Miller-Foot and Ankle Flashcards
What is tolertail
TOLERTIAL” - at “T”oe “O”ff “L”eg “E”xternally “R”otates “T”alus “I”nverts “A”nd “L”ocks. John Ayres MD
How do you lock the foot?
Function of the transverse tarsal joint. When the heel is everted, the transverse tarsal joints are parallel and unlocked, allowing the foot to be supple and pronate and accommodate to the floor. When the heel is inverted (varus), the transverse tarsal joint is divergent and locked, allowing for a stable hindfoot/midfoot complex for toe-off.
review hindfoot/forefoot motion
The critical assessment is to determine the relationship of the forefoot to the hindfoot.
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If the heel is in a neutral position (subtalar neutral), the forefoot should be parallel with the floor to meet the ground flush (plantigrade).
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If the first ray is elevated, the forefoot is in varus position. If the first ray is flexed, the forefoot is in valgus position (see Fig. 6.3). This should not be confused with hindfoot varus or valgus.
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Example: in a long-standing flatfoot deformity the heel is valgus and the forefoot has compensated by going into varus or supinating to keep the foot flat to the ground.
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Once the heel has been corrected, the elevated first ray can be easily seen
Review the gait cycle
One full gait cycle from heel strike to heel strike is termed a stride.
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Each stride is composed of a stance phase (heel strike to toe-off; 62% of cycle) and a swing phase (toe-off to heel strike; 38% of cycle) (Fig. 6.10).
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Walking is defined by a period of double-limb support in addition to there always being one foot in contact with the ground throughout the gait cycle.
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Ground reaction forces are approximately 1.5 times body weight during walking and 3 to 4 times body weight during running.
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This difference is due to the increased load after the float phase of running, in which there is no foot in contact with the ground.
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As the speed of gait increases, the stance phase decreases.
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Soft-tissue contributions to gait mechanics
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Swing phase
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Anterior tibialis—contracts concentrically
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Loss of function results in footdrop and steppage gait.
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Heel strike
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Anterior tibialis—contracts eccentrically
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Controls the rate at which foot strikes the ground. In patients with footdrop, the rapid strike of the foot can result in a loud “slap” during heel strike.
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Hindfoot—locked/inverted at initial strike; passively everts during transition from heel strike to foot flat
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Allows for energy absorption. Failure of hindfoot eversion in patients with cavovarus deformity increases forces to lateral foot, resulting in stress fractures (fifth metatarsal), callus formation, and ankle instability.
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Foot flat
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Gastrocnemius-soleus complex—eccentric contraction
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Controls forward progression of body over the foot
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Loss of function results in a calcaneus gait with heel pain
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Hindfoot—unlocked/everted for ground accommodation
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At terminal stance, the FDL tendon is most active
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Toe-off
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Gastrocnemius-soleus complex—concentric contraction
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In addition, as foot progresses from heel strike to toe-off, the following changes allow foot to convert from a flexible shock absorber to a rigid propellant:
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Plantar fascia, which attaches to plantar medial heel and runs the length of the arch to the bases of each proximal phalanx, is tightened as MTP joints extend. The longitudinal arch is accentuated.
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This is called the windlass mechanism (Fig. 6.11).
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Hindfoot supinates, with firing of the PTT.
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Transverse tarsal joint locks and provides a rigid lever arm for toe-off.
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Insufficiency of the PTT will limit the ability to lock the transverse tarsal joint.
Halgus Valgus Schemata
chematic representation of tendons around the first metatarsal head. (A) Normal articulation in a balanced state. (B) Relationship of the tendons in hallux valgus deformity. FHBL, Lateral head of the FHB; FHBM, medial head of the FHB.
What is the Halgus Valgus Angle?
Hallux valgus angle. Marks are placed in the middiaphyseal region of the proximal phalanx and the first metatarsal at equal distances from the medial and lateral cortices. The longitudinal axis of the proximal phalanx is determined by an axis drawn through points A and B, and the longitudinal axis of the first metatarsal is determined by a line drawn through points C and D. The hallux valgus angle is formed by the intersection of the diaphyseal axes of the first metatarsal (line CD) and the proximal phalanx (line AB).
What is the IMMA?
First–second intermetatarsal angle. Middiaphyseal reference points (X) are placed equidistant from the medial and lateral cortices of the first (C and D) and second (E and F) metatarsals in both the proximal and distal middiaphyseal region. The longitudinal axis is drawn for both the first metatarsal (line CD) and the second metatarsal (line EF). The first–second intermetatarsal angle is formed by the intersection of these two axes (lines CD and EF).
what is the halgus valgus IP angle?
Hallux valgus interphalangeal angle. On the proximal phalanx, reference points (X) are drawn at middiaphysis. On the distal phalanx reference points are placed at the distal tip of the phalanx and at the midpoint of the articular surface of the distal phalanx. A line is drawn to connect the reference points for the axes of each phalanx. Line A indicates the proximal phalanx axis. The intersection of the axis of the distal phalanx with the longitudinal axis of the proximal phalanx forms the hallux valgus interphalangeal angle.
review the plan for surgical fixation of Halgus Valgus
Schemes of surgical fixation for Halgus Valgus
Lateral and AP drawings delineating various surgical options for management of hallux valgus. It is important to note that a distal soft tissue release is performed in conjunction with all corrections. The exception to this is a hallux MTP joint fusion.
Halgus Valgus text miller Review
Hallux valgus is defined as lateral deviation of the great toe with medial deviation of first metatarsal.
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Pathophysiology: likely multifactorial
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Intrinsic factors such as genetic predisposition, ligamentous laxity, and predisposing anatomy (convex metatarsal head, pes planus) are contributory.
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Extrinsic factors such as certain types of shoewear (narrow toe box, high heels) also play a role.
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Pathoanatomy (Fig. 6.26)
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Medial capsular attenuation
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Proximal phalanx drifts laterally, leading to the following conditions:
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Plantar-lateral migration of abductor hallucis (ABH); change in position causes the muscle to plantar flex and pronate the hallux.
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The pronation of the hallux is amplified by the proximal phalangeal attachment of the adductor hallucis (ADH).
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Stretching of the extensor hood of the extensor hallucis longus (EHL)
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Lateral deviation of the EHL and flexor hallucis longus (FHL), causing a muscular imbalance and deforming force for valgus progression and pronation of the great toe (Fig. 6.27)
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First metatarsal head moves medially off the sesamoids, increasing the intermetatarsal angle (IMA).
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Secondary contracture of the lateral capsule, adductor hallucis, and lateral metatarsal-sesamoid and intermetatarsal ligaments
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Radiographs
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Multiple measurements can be obtained from standard radiographs that guide treatment options.
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Hallux valgus angle (HVA): angle formed by line along first metatarsal shaft and line along shaft of proximal phalanx (Fig. 6.28)
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Normal: less than 15 degrees
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First–second IMA: angle formed by lines along first and second metatarsal shafts (Fig. 6.29)
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Normal: less than 9 degrees
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Hallux valgus interphalangeus (HVI) angle: angle formed by lines along shafts of the proximal phalanx and distal phalanx (Fig. 6.30)
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Normal: less than 10 degrees
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Associated with a congruent deformity
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Distal metatarsal articular angle (DMAA): angle formed by line along articular surface of first metatarsal and line perpendicular to axis of first metatarsal (Fig. 6.31)
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Normal: less than 10 degrees
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Increased angle associated with a congruent deformity.
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Congruency of first MTP joint must be determined (Fig. 6.32).
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Congruency is determined by comparing the line connecting the medial and lateral edges of the first metatarsal head articular surface with the similar line for the proximal phalanx.
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When these lines are parallel, the joint is congruent.
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Increased DMAA
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Distal redirectional osteotomy of the metatarsal head (medial closed-wedge osteotomy)
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Increased HVI
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Akin osteotomy—medial closed-wedge osteotomy of the phalanx
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Both of these operations may be required in addition to an osteotomy of the metatarsal to correct the increased IMA. Performing these osteotomies does not exclude additional distal or proximal metatarsal correction.
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When these lines are divergent, the joint is incongruent.
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Patients may present with both an incongruent joint and increased DMAA or HVI in severe deformities.
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Position of sesamoids should be noted; in more severe or chronic deformities, the sesamoids are frequently displaced laterally.
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Presence of degenerative changes in first MTP joint and first TMT joint should be noted.
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A stiff or arthritic MTP joint requires a first MTP arthrodesis.
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Nonoperative treatment
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Adjusting shoewear and increasing the size of the toe box may limit pain with pressure along the prominent dorsomedial eminence.
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There is no role for “corrective” braces or splints.
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Operative treatment
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The best indication for operative intervention is pain that has not responded to adjustments in shoewear or activity. Surgical correction of a hallux valgus deformity is not a cosmetic procedure.
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The appropriate surgical procedure is determined by the abnormal radiographic angular measurements in concordance with underlying clinical abnormalities.
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The patient’s physical findings and associated pathology dictate the appropriate surgical procedure regardless of the angular measurements.
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First MTP fusion required for following conditions; IMA will correct with realignment of first MTP; concomitant metatarsal osteotomy is notrequired (Fig. 6.33).
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Rheumatoid arthritis (RA)
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Osteoarthritis
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Painful or stiff first MTP—deformity cannot be passively corrected
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Spasticity
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Stroke
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Cerebral palsy
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Lapidus (first TMT realignment arthrodesis) required for:
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Ligamentous laxity
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First TMT DJD
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Procedures never appropriate in isolation (high recurrence rate)
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Distal soft tissue release (modified McBride procedure)
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Modification—retention of the lateral (fibular) sesamoid to avoid hallux varus
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Medial eminence resection
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Medial capsular imbrication
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Isolated osteotomy without associated soft tissue correction
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Algorithmic approach to identifying the appropriate surgical intervention is listed in Box 6.1
Box 6.1Algorithmic Approach to Surgical Correction of Hallux Valgus
IMA ≤13 degrees AND HVA ≤40 degrees
Distal metatarsal osteotomy (chevron)
IMA >13 degrees OR HVA >40 degrees
Proximal metatarsal osteotomy
Instability of the first TMT/joint laxity
Lapidus (fusion of first TMT joint)
Arthritis or spasticity
First MTP fusion
Increased DMMA
Distal metatarsal redirectional osteotomy in addition to metatarsal translational osteotomy
HVI
Akin osteotomy
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All patients should undergo a soft tissue release with all associated osteotomies and first TMT arthrodesis (Lapidus procedure) (Fig. 6.34).
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IMA 13 degrees or less and HVA 40 degrees or less
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Distal metatarsal osteotomy (chevron)
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Distal soft tissue release
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Medial eminence resection and capsular repair
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IMA greater than 13 degrees or HVA greater than 40 degrees
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Proximal metatarsal osteotomy/scarf
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Distal soft tissue release
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Medial eminence resection and capsular repair
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Instability of first TMT/joint hyperlaxity
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Lapidus procedure (fusion of first TMT joint) (Fig. 6.35)
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Soft tissue release
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Medial eminence resection and capsular repair
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Increased DMAA (>10 degrees)
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Distal medial closed-wedge metatarsal osteotomy in addition to what is required by angular measurements (Fig. 6.36)
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IMA 13 degrees or less and HVA 40 degrees or less
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Distal biplanar closed-wedge metatarsal osteotomy
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Translates and redirects the metatarsal head simultaneously.
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IMA greater than 13 degrees or HVA greater than 40 degrees
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Proximal metatarsal osteotomy and distal medial closed-wedge metatarsal osteotomy
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Instability of first TMT/joint hyperlaxity
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Lapidus procedure and distal medial closed-wedge metatarsal osteotomy
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If there is arthritis or pain at the first TMT, consider a Lapidus procedure
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Hallux valgus interphalangeus
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Akin osteotomy
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Can be done in isolation if no other deformity present
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Commonly performed in addition to procedures required to correct HVA and IMA (Fig. 6.37)
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Operative complications
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Avascular necrosis (AVN)
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Distal metatarsal osteotomy and lateral soft tissue release may be performed simultaneously without increased risk of AVN.
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Intraoperative laser Doppler study demonstrated that medial capsulotomy primary is insult to metatarsal head blood flow.
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Care must be taken with vascular pedicle dorsolaterally.
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Recurrence
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Can occur with any procedure—highly associated with:
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Undercorrection of IMA
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Isolated soft tissue reconstruction (modified McBride procedure)
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Isolated resection of the medial eminence
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Persistent lateral subluxation of the sesamoids
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Dorsal malunion
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Results in transfer metatarsalgia—highly associated with:
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Lapidus procedure (first TMT fusion)
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Often related to inadequate preparation of plantar joint (depth of first TMT is ≈30 mm)
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Proximal crescentic osteotomy
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Hallux varus—associated with:
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Resection of the fibular sesamoid (original McBride procedure)
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Overresection of the medial eminence
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Excessive lateral release
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Overcorrection of IMA
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Nonunion
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Highest risk associated with a Lapidus procedure
Anatomy and function of lesser toe deformities
Static stability of the lesser toes is provided by the congruency of the MTP and interphalangeal joints.
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Plantar plate—plantar aponeurosis and capsule—provides a soft tissue block to metatarsal head depression and prevents hyperextension of the MTP joint.
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Persistent hyperextension at MTP joint may lead to attenuation and weakening of plantar structures.
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Dynamic stability is provided by the various tendons that insert on lesser toes (Fig. 6.41).
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Extensor digitorum longus: primary extensor of MTP joint
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Runs through a sling over dorsal surface of MTP joint before splitting into a central slip that inserts on the middle phalanx and two dorsolateral slips that reconverge to insert at the base of the distal phalanx.
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Distal extensor effect of the EDL is neutralized when the proximal phalanx is dorsiflexed, as in hammer-toe or claw-toe deformity.
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There is no EDL to the fifth digit.
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Extensor digitorum brevis (EDB) extends PIP joints and inserts on lateral aspects of EDL tendons on all but the fifth toe.
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Flexor digitorum longus: primary plantar flexor of distal interphalangeal (DIP) joints as it inserts on plantar aspects of distal phalanges; also weakly plantar flexes MTP joints.
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Flexor digitorum brevis (FDB) splits at the level of the MTP joint and inserts on plantar lateral aspects of the middle phalanges. The FDB is the primary plantar flexor of the PIP joints.
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Intrinsic muscles of the foot include the lumbricals, which originate from the FDL tendon and insert on the extensor sheath over the MTP joints, and four dorsal and three plantar interossei muscles, which insert on the medial aspects of the proximal phalanges.
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These muscles act similarly to the intrinsic muscles of the hand, flexing the MTP joints and extending the PIP and DIP joints.
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Pull of the intrinsics is plantar to the rotational axis of the MTP joints.
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Plantar translation of the metatarsal head after a distal osteotomy of the metatarsal places the intrinsics dorsal to the axis of rotation of the MTP joint, creating the “floating toe.”
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Extrinsic muscles (EDL and FDL) overpower intrinsic muscles in positioning the lesser toes in hammer- and claw-toe deformities, with the EDL driving MTP joint extension and the FDL driving PIP and DIP joint flexion.
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EDL is also a weak antagonist to flexion at interphalangeal joints, and likewise, the FDL is a weak antagonist to extension at MTP joint.
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There is no flexor (FDL/FDB) attachment to the proximal phalanges.
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Dorsiflexion of the proximal phalanx at MTP joint neutralizes these weak antagonist effects and accentuates the developing deformity.
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Lesser-toe deformities occur much more commonly in women (up to a 5:1 ratio); difference thought to be secondary to high-fashion shoewear that constricts the forefoot and maintains the MTP joints in hyperextension.
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A hammer-toe deformity most commonly involves the second toe, because it is relatively longer than the other lesser toes. A short toe box causes the second toe to buckle and extend at the MTP joint.
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Long-term positioning of the MTP joint in hyperextension will attenuate the static plantar structures, allowing depression of the metatarsal head, distal migration of the fat pad, and imbalance of the dynamic forces on the toe, as described earlier.
what are the surgical treatment options for lesser toe deformities?
Review Hammer toe deformity
The characteristic hammer-toe deformity is flexion of the PIP joint. With weight bearing, the MTP joint appears dorsiflexed; this should correct with elevation of the foot off the ground (Fig. 6.42).
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Contracture of the FDL is responsible for the flexible hammer-toe deformity
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The term complex hammer toe refers to concomitant dorsiflexion of the MTP joint that does not correct and is more appropriately termed (and treated as) a claw toe.
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Treatment depends on the flexibility of the deformity (Table 6.3).
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Flexible deformity
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Nonoperative—protective padding, tall toe-box shoes, corrective hammer-toe splints are effective.
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Operative—flexor tenotomy or flexor to extensor tendon transfer
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Fixed deformity
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Nonoperative—accommodative shoes and protective padding can minimize callus formation. A corrective splint should not be used (Fig. 6.43).
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Operative—PIP arthroplasty (resection of distal neck and head of proximal phalanx) or PIP arthrodesis
Review Claw toe deformity
Characterized by flexion of the PIP and DIP joints in the setting of fixed hyperextension of the MTP joint (Fig. 6.44)
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Clawing typically involves multiple toes and is often bilateral.
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Results from dysfunction of the intrinsic musculature
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Often a neurogenic etiology
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Cavus deformity, neuromuscular diseases that affect the balance of the extrinsic and intrinsic musculature, inflammatory arthropathies that lead to attenuation of soft tissue structures and instability of the MTP joint, and trauma have all been implicated in the etiology of claw toes.
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Claw toes are a noted complication of compartment syndrome involving the deep compartments of the foot.
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Treatment depends on the flexibility of the deformity (see Table 6.3).
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Flexible deformity
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Nonoperative—shoe modification, padding over any prominent or painful callosities, and use of orthotics to offload and support a potentially painful, plantarly displaced metatarsal head
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Operative
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Flexor-to-extensor tendon transfer of the FDL alters the function of the FDL to function as an intrinsic and to maintain the correction (Fig. 6.45).
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Often leads to stiffness of MTP joint
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Lengthening of the EDL and EDB is typically required.
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Fixed deformity
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Nonoperative—shoe modification, padding over any prominent or painful callosities, and use of orthotics to offload and support a potentially painful, plantarly displaced metatarsal head
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Operative
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PIP arthroplasty or arthrodesis, along with MTP joint capsulotomy and extensor lengthening
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Dislocated MTP joint requires use of a Weil or distal metatarsal shortening osteotomy to reduce the MTP joint (Fig. 6.46).
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Review mallet toe deformity
A mallet toe consists of an isolated flexion deformity at the DIP joint (Fig. 6.47).
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Treatment (see Table 6.3)
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Nonoperative—similar methods to those used in treating hammer-toe and claw-toe deformities
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Operative
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Flexible deformity
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Flexor tenotomy
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Fixed deformity
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DIP arthroplasty (excision of the distal neck and head of the middle phalanx) or DIP fusion
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Extensor repair can be performed to minimize recurrence.
Review crossover toe deformity
Multiplanar instability of the second toe may cause the toe to lie dorsomedially relative to the hallux (Fig. 6.48).
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Commonly referred to as a crossover second toe, this deformity:
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Requires disruption of the plantar plate—KEY component
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Requires attenuation of the lateral collateral ligament
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May be iatrogenic—caused by steroid injection within the MTP joint, which results in plantar plate attenuation
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Treatment
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Nonoperative—toe taping and corrective splints can minimize the discomfort but will not permanently correct the deformity.
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Operative
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For complete tears of the plantar plate, plantar plate repair has been advocated, with promising results. Plantar plate repair typically requires a shortening osteotomy of the distal metatarsal to aid in visualization and tissue repair.
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Flexor-to-extensor tendon transfer with release of the medial collateral ligament
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EDB tendon transfer with rerouting plantar to the intermetatarsal ligament
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Reserved for less severe deformities; leads to more mobility of MTP joint than a flexor-to-extensor transfer
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Distal metatarsal osteotomy (Weil) required if severe subluxation or dislocation of the MTP joint
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If there is skin break down at the PIP dorsally, surgical débridement (with obtaining of specimen cultures) and delay of definitive treatment must be considered
Plantar plate pathology
Mild subluxation of the MTP joint that manifests as pain and swelling without any deformity
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Drawer test results in pain within the joint (Fig. 6.49).
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Most sensitive physical examination test to evaluate for plantar plate injury
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More commonly seen in athletes (runners, tennis)
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If the diagnosis is in question, an MR arthrogram of the involved joint will identify any injuries to the plantar plate or collateral ligaments.
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Treatment
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Nonoperative
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Toe taping and stabilizing lesser-toe orthotics/metatarsal pads
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Steroid injections are contraindicated and may result in iatrogenic creation of a crossover-toe deformity.
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Operative
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MTP synovectomy with reconstruction of the MTP joint capsule for isolated synovitis
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With severe instability or deformity, a flexor-to-extensor tendon transfer is traditionally performed to stabilize MTP joint.
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For complete tears of the plantar plate, plantar plate repair has been advocated.
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Especially in high-level athletes
Review Friedburg infarction
Osteochondrosis (avascular necrosis) of one of the lesser metatarsals, most commonly involving the second metatarsal
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Patient has pain localized over the affected metatarsal head.
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The second metatarsal is affected in over two-thirds of cases. The third metatarsal accounts for most of the remaining cases. The fourth is affected in less than 5% of cases. The first and fifth metatarsals are rarely affected.
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Pain is worse with ambulation and activities, and relieved with rest.
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Common radiographic findings in Freiberg disease include:
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Resorption of the central metatarsal bone adjacent to the articular surface, with flattening of the metatarsal head (Fig. 6.50)
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Osteochondral loose bodies
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Joint space narrowing in late-stage disease, with associated osteophyte formation along with collapse of the articular surface (Fig. 6.51)
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Nonoperative treatment
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Common strategies consist of activity modification, shoewear modification (hard sole), orthotics (metatarsal bar), and a period of protected weight bearing.
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Operative treatment
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For early-stage disease, joint débridement should be considered.
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All inflamed synovium, osteophytes, and loose bodies are débrided through a dorsal incision.
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This procedure should be considered for patients with relatively good articular surface congruity and minimal metatarsal deformity.
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Many studies have reported good results with dorsal closed-wedge metaphyseal osteotomy of the affected metatarsal (Fig. 6.52).
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Performed in conjunction with a thorough débridement of inflamed synovium, abnormal cartilage, osteophytes, and necrotic bone
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Serves to rotate the plantar aspect of the articular surface, which is typically well preserved, to a more superior position, where it then articulates with the phalanx
What is IPK?
Intractable plantar keratosis?
Plantar callus secondary to excess pressure from metatarsal head
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Predisposing factors: fat pad atrophy, plantar-flexed first ray, equinus contracture, intrinsic minus toe contracture, and hypertrophy of the sesamoid
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Two main types (Fig. 6.53):
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Discrete form
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Localized callus with a hyperkeratotic core, usually caused by prominence of fibular/lateral condyle of the lesser metatarsal head
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Commonly associated with a prominent tibial sesamoid
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Nonoperative treatment
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Callus trimming and soft metatarsal pads
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Total-contact orthosis or extended steel shank should be considered for patients with significant fat pad atrophy.
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Operative treatment
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Shaving of the plantar surface of the tibial sesamoid or fibular metatarsal condylectomy
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In more advanced cases, complete excision of the tibial sesamoid should be considered.
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In the patient with a plantar-flexed first ray, dorsiflexion osteotomy should be considered.
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Diffuse form
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Secondary to pressure phenomenon from the entire metatarsal head
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Commonly associated with an elongated metatarsal, an excessively plantar-flexed metatarsal, or transfer lesion. If there is no first ray pathology, it is important to evaluate for the presence of a gastrocnemius contracture.
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Nonoperative treatment—similar to the discrete form of IPK
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Operative treatment
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Correction of the underlying deformity is critical— revision of the first ray to restore weight bearing through the medial column is critical
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Secondary shortening of the lesser metatarsals may be required if the first ray is excessively short; however, shortening should not be done without correction of first ray pathology.
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Gastrocnemius recession as required by the physical examination findings
what is bunionette deformity?
Prominence over distal aspect of fifth metatarsal head
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Causes pain over lateral or plantar aspect of MTP joint, particularly with compressive shoewear
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Bunionette deformity in conjunction with ipsilateral hallux valgus and metatarsus primus varus is termed splayfoot.
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Three distinct types have been described, based on the anatomic location of the deformity along the fifth metatarsal:
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Type I deformity—distinguished by presence of an enlarged fifth metatarsal head (Fig. 6.54)
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Type II deformity—demonstrates lateral bowing of fifth metatarsal diaphysis (Fig. 6.55)
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Type III deformity—demonstrates an abnormally widened fourth–fifth metatarsal angle (normal <8 degrees) (Fig. 6.56)
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Conservative treatment
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Shoewear modification, strategic padding, and shaving of the symptomatic callus are usually effective.
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With plantar callus or associated pes planus, a metatarsal pad or custom orthotic device should be considered.
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Surgical treatment
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Lateral metatarsal head condylectomy (type I deformity)
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Distal fifth metatarsal osteotomy (i.e., chevron; type II deformity)
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Oblique diaphyseal osteotomy (type III deformity)
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Metatarsal head resection should be considered for salvage.
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Proximal osteotomy should be avoided owing to the tenuous blood supply at the proximal metadiaphyseal junction of the fifth metatarsal.
review the anatomy of the seasamoids
Medial (tibial) and lateral (fibular) hallucal sesamoids are part of a strong sesamoid capsuloligamentous complex.
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Enveloped within the two heads of the flexor hallucis brevis (FHB) tendon, separated by an intersesamoid ridge called the crista
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Attached to proximal phalanx via the plantar plate
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Suspended by the collateral ligaments of MTP joint, metatarsosesamoid ligaments, intersesamoid ligament, abductor hallucis tendon, and adductor hallucis tendon
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Analogous to the patella, sesamoids provide a mechanism to increase the mechanical advantage of the pulley function of the intrinsics (FHB).
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Protect the FHL and disperse the forces beneath the first metatarsal head
Review seasamoid deformity
Sesamoid disorders can include acute injury (fracture, dislocation, sprain/“turf toe”), sesamoiditis, stress fracture, arthrosis, AVN, and IPK.
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Diagnosis
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Chief complaint is pain under the first metatarsal head, especially with toe-off.
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Physical examination—tenderness with direct palpation of the involved sesamoid, pain with first-MTP ROM
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Radiographs—in addition to AP and lateral views, lateral oblique (fibular sesamoid) and medial oblique (tibial sesamoid) views isolate each bone, and axial view shows the articulation with the metatarsal head (Fig. 6.57).
•
Radiographs of contralateral side should be obtained to compare position of sesamoids relative to the base of the proximal phalanx.
•
Tibial sesamoid should be 10.4 mm from the base, and fibular sesamoid should be 13.4 mm from the base.
•
Should be within 3 mm of the spaces on the contralateral extremity
▪
Mechanism of injury—forced dorsiflexion of the first MTP joint, repetitive loading
□
Turf toe—forced dorsiflexion with foot in equinus (and axial load) can result in avulsion of the plantar plate off the base of the phalanx and subsequent proximal migration of the sesamoids.
•
Hyper–plantar flexion of MTP joint with valgus force is a less common mechanism; seen in beach volleyball players.
•
Tibial sesamoid is more frequently involved in trauma but also more likely to be bipartite or multipartite.
▪
Conservative treatment
□
Turf toe
•
Grade 1—capsular strain
•
Signs—normal ROM, weight bearing without difficulty, normal radiographs
•
Treatment—stiff insole, taping, with immediate return to play
•
Grade 2—partial capsular tear
•
Signs—painful ROM, limited weight bearing, normal radiographs
•
Treatment—no athletic activity for 2 weeks, stiff insole, return to play if painless 60-degree dorsiflexion present
•
Grade 3—complete tear of the plantar plate
•
Signs—severe pain with palpation, limited and painful ROM, abnormal radiographs (fracture, proximal sesamoid migration)
•
Treatment—superior results demonstrated with operative repair of the plantar plate over conservative care.
□
Traumatic hallux valgus that involves the medial capsule and medial sesamoid with acute deformity of the hallux is best treated with immediate surgical repair as opposed to late reconstruction.
□
Sesamoid fracture
•
Initial treatment with a fracture boot to limit the stress across the sesamoid
•
Transition to sesamoid relief pad (dancer’s pad) with gradual resumption of activity
□
Sesamoiditis
•
Treated with antiinflammatory medications, rest, ice, and activity, and then shoewear modification
•
Operative treatment
•
Symptomatic nonunion or cases that prove refractory to conservative care can be treated surgically with bone grafting or with partial or complete sesamoidectomy.
•
Results of sesamoidectomy are the most predictable.
•
Excision of the proximal or distal pole achieves the best results and should be performed if the fracture pattern allows.
•
Complications of medial and lateral sesamoidectomy are hallux valgus and varus, respectively.
•
Repairing the defect with capsule (or a slip of abductor hallucis for the tibial sesamoid) helps prevent this complication.
•
Cock-up deformity (or claw toe) will occur if both sesamoids are excised (Fig. 6.58).
•
Care should be taken to avoid injury to the FHL and loss of flexor function, especially in the high-performance athlete.
review pes planus
May be congenital (see Chapter 3, Pediatric Orthopaedics) or acquired (also called adult-acquired flatfoot deformity [AAFD])
▪
Determining whether the deformity is flexible or fixed is important
□
Fixed or rigid deformity requires a triple arthrodesis.
▪
Tarsal coalitions tend to cause rigid flatfoot deformities.
▪
Present in adolescence or later
▪
50% bilateral
▪
1 in 100 people affected
▪
Diagnostics: radiographs and CT scans
▪
Treatment
□
Nonoperative: rests, walking boot, casts, injections
□
Operative: resection and interposition with muscle/fatty tissue if less than 50% of middle facet is involved; arthrodesis if more than 50%
▪
Pathology
□
Most common cause of AAFD is PTTD.
•
PTT is the primary dynamic support for the arch.
•
PTT fires after the foot is flat to generate heel rise and lock the transverse tarsal joint for a rigid, stable foot during push-off (toe-off).
•
The tibia rotates externally and the transverse tarsal locks as the PTT fires during push-off.
•
Etiology of PTTD is multifactorial and includes:
•
Zone of hypovascularity 2–6 cm proximal to the PTT insertion on the navicular
•
Overload of the arch due to activity or obesity
•
Inflammatory disorders such as RA
□
The spring (calcaneonavicular) ligament is the primary static stabilizer of the TN joint.
•
Incompetence of the spring ligament is associated with increased flatfoot deformity.
•
Most commonly the superomedial band (70%)
•
Isolated acute rupture of the spring ligament has been reported to cause an acute deformity without PTTD.
•
Reconstruction of the spring ligament with allograft or autograft as an adjunct to standard flatfoot reconstruction has shown success in early series.
review PTT deficiency
Patients complain of medial ankle/foot pain early, progressive loss of arch, and lateral ankle pain late (subfibular impingement).
□
Physical examination
•
Standing examination demonstrates asymmetric hindfoot valgus, depressed arch, and an abducted forefoot.
•
Too-many-toes sign: when the foot is viewed posteriorly, it appears to have more than five toes (Fig. 6.86)
•
Pain or inability to perform single-limb heel rise indicates insufficient PTT.
•
Whether deformity is flexible (passively correctable to a plantigrade foot) or fixed (rigid deformity that is not passively correctable) must be determined
•
Lateral impaction syndrome or subfibular impingement with significant valgus of the heel, such that it abuts the fibula, may be present; abutment of the lateral process of the talus and the calcaneus can occur as well.
□
Radiographs (Fig. 6.87)
•
Pes planus indicated by negative lateral talar–first metatarsal angle (Meary angle)
•
Forefoot abduction indicated by TN uncoverage
Review the treatment stages of Pes Planus PTT disorder
Stage I—tenosynovitis without deformity
•
Nonoperative
•
Immobilization (cast or boot)
•
Orthotic after acute swelling and pain subside
•
Arch support with medial heel wedge
•
Operative
•
Synovectomy of PTT
□
Stage II—flexible deformity is the critical feature; PTT is degenerated and functionally incompetent.
•
Nonoperative
•
AFO in conjunction with physical therapy has demonstrated the highest success rate.
•
Use of a full-length orthotic with an arch support, medial heel wedge, and medial forefoot support (if supination/forefoot varus present) is used after acute pain has resolved.
•
A lace-up ankle brace may also be used.
•
Operative (if conservative measures fail after 6 months or more)
•
Correction of all stage II deformities includes a tendon transfer (FDL or FHL) into the navicular to reconstruct the PTT.
•
Presence of a gastrocnemius contracture should be assessed for and if present corrected with a gastrocnemius recession.
•
Although reconstruction of the spring ligament has been advocated, there are limited data to demonstrate its efficacy at this time.
•
Stage IIA—defined by hindfoot valgus without significant forefoot abduction (<40% uncovering of the talus)
•
Medial slide calcaneal osteotomy (Fig. 6.88)
•
To address signs of subfibular impingement
•
Stage IIB—defined by forefoot abduction (>40% uncovering of the talus) in addition to hindfoot valgus
•
Lateral column lengthening (Fig. 6.89)
•
To address hindfoot valgus and improve the longitudinal arch of the foot/medial column of the foot
•
Additional medial slide calcaneal osteotomy may be required.
•
Stage IIC—defined by fixed forefoot supination/varus (first ray is elevated after correction of the hindfoot to neutral) in addition to hindfoot valgus (Fig. 6.90). Forefoot abduction may also be present.
•
Stable medial column—navicular is colinear with first metatarsal.
•
Cotton osteotomy (dorsal open-wedge osteotomy of the cuneiform) to plantar flex the first ray, to correct forefoot varus
•
Unstable medial column—plantar sag at NC or first TMT joint
•
Medial column fusion (based on point of collapse)
•
Isolated first TMT fusion
•
Isolated NC fusion
•
Combined NC and TMT fusion (both joints are involved radiographically)
•
Hindfoot treatment based on talar uncovering
•
Less than 40%—medial slide calcaneal osteotomy
•
More than 40%—lateral column lengthening and possible medial slide calcaneal osteotomy if residual hindfoot valgus
•
Stage II surgical summary
•
FDL or FHL tendon transfer for all patients
•
Gastrocnemius recession if contracture present
•
Hindfoot valgus—medial slide calcaneal osteotomy
•
Forefoot abduction—lateral column lengthening
•
Forefoot supination
•
Stable medial column—Cotton osteotomy
•
Unstable medial column—first TMT arthrodesis
□
Stage III—defined by a fixed/rigid pes planovalgus deformity
•
Nonoperative
•
Accommodative rigid AFO or Arizona brace. No attempt should be made to correct the deformity—correction carries increased risk of pain and pressure points, leading to ulceration.
•
Operative
•
Triple arthrodesis
•
If subtalar arthrodesis (alone or as part of triple) has been malunited in valgus, with tenderness in the lateral subfibular region, arthrodesis takedown and revision arthrodesis may be required.
•
Severely abducted deformities may require an all-medial approach, to limit risk of wound healing issues with the sinus tarsi approach.
•
Some authors argue that the calcaneocuboid joint is challenging to see, but cadaveric studies have demonstrated the ability to see >90% of each joint from the medial approach alone.
•
Additional medial column stabilization is occasionally needed for severe deformities (Fig. 6.91).
•
TAL if equinus contracture present
•
Stage IV—defined by incompetence of the deltoid ligament; standing AP ankle radiograph demonstrates lateral talar tilt (valgus) or ankle arthritis.
•
If the ankle valgus is passively correctable with minimal degenerative changes, an attempt can be made at deltoid ligament reconstruction with hindfoot reconstruction.
•
Rigid deformity or progressive arthritis requires TTC arthrodesis (Fig. 6.92).
Review the Diagnosis of Pes Cavus deformity
Defined by a high-arched foot, often with associated heel varus (cavovarus)
▪
Pathology
□
Neuromuscular
•
Unilateral—tethering of the spinal cord or spinal cord tumors must be ruled out.
•
Bilateral—most commonly Charcot-Marie-Tooth (see Section 11, Neurologic Disorders)
•
Idiopathic—usually subtle, bilateral
•
Traumatic—secondary to talus fracture malunion, compartment syndrome, crush injury
▪
Diagnosis
□
Patients complain of painful calluses under the first metatarsal, fifth metatarsal, and medial heel.
•
There may be pain along the peroneal tendons as well.
•
These may need to be addressed as part of surgical intervention.
•
Secondary to the plantar-flexed first ray and varus hindfoot
•
Plantar flexion of the first ray is secondary to overpowering of the tibialis anterior by the peroneus longus.
•
Varus of the hindfoot is secondary to the overpull of the PTT.
•
On an adequate weight-bearing, lateral foot radiograph, visibility of the middle facet of the subtalar joint indicates varus hindfoot.
□
Often associated with lateral ankle ligament instability, peroneal tendon pathology
□
Coleman block test used to assess flexibility of the hindfoot (out of varus) when the first metatarsal plantar flexion (forefoot valgus) is eliminated.
•
Wooden block placed just lateral to the first ray; first metatarsal head then lies off the block, with remainder of block on the weight-bearing foot.
•
If the hindfoot passively corrects into valgus, the deformity is forefoot driven (due to plantar-flexed first ray).
Review the treatment for pes cavus
Dwyer closed-wedge osteotomy of calcaneus for varus heel. (A) Lateral skin incision is made inferior and parallel to peroneal tendons. (B) Wedge of bone is resected with its base laterally. (C) Wedge of bone is tapered medially. (D) Calcaneus is closed after bone has been removed, and varus deformity is corrected to slight valgus.
Forefoot driven treatment-often times need forefoot osteotomy
what is the non-operative treatment for pes cavus?
Cavus foot orthotic. Note the hollowed-out recess under the first metatarsal head, laterally based forefoot wedge, and lowered medial arch.
Review Morton’s Neuroma
Compressive neuropathy of the interdigital nerve, most commonly in the third web space, followed by the second web space (Fig. 6.60)
□
The pathophysiology of this condition is still poorly understood.
•
Theories include compression/tension around the IM ligament, repetitive microtrauma, vascular changes, excessive bursal tissue, endoneural edema, and eventual perineural fibrosis.
▪
Diagnosis
□
Patients frequently report pain and burning on the plantar aspect of the web space, with more than 60% of patients noting pain radiating into the toe distally. Numbness is reported by only 40% of patients.
□
Exacerbated by footwear with narrow toe boxes and high heels
•
Higher predilection in the female population
•
Likely related to shoewear, with forced plantar flexion of the metatarsal heads
□
Physical examination
•
Palpation between and just distal to the metatarsal heads elicits plantar tenderness.
•
Compressing the medial and lateral aspects of the forefoot while palpating the web space structures can provoke symptoms and occasionally a bursal “click” with associated pain (Mulder sign).
•
Metatarsalgia and MTP synovitis often manifest similarly and should be ruled out.
□
Radiographs
•
Plain films should be obtained to rule out bony masses or deformity.
•
MRI or ultrasound can be used to identify other pathologies but are not required for diagnosis.
▪
Nonoperative treatment
□
Shoewear modification (avoiding high heels and narrow toe boxes) is the most important and effective intervention.
□
Metatarsal pads placed proximal to the focus of pain can prevent direct pressure and widen the intermetatarsal space during weight bearing, thereby indirectly decompressing the nerve.
□
Corticosteroid injections can have moderate effectiveness (≈50% of patients report positive response); repetitive injections can lead to hammer-toe deformity.
□
Alcohol sclerosing injections have not proved to be effective and are not recommended.
▪
Operative treatment
□
Excision of neuroma
•
Dorsal approach most common
•
Transverse intermetatarsal ligament is incised and resected.
•
The common digital nerve and its branches are identified and the nerve is resected 2 to 3 cm proximal to the intermetatarsal ligament (proximal to the small plantar branches), allowing the proximal stump to retract (Fig. 6.61).
•
Minimizes formation of stump neuroma, the most common complication
•
Difficult visualization results in a 4% rate of failure to excise the neuroma.
•
Overall success rates approach 80%.
•
Neuroma often causes perineural fibrosis.
•
Plantar approach
•
Decreases the rate of missed neuroma excision
•
Does not require incision of the transverse intermetatarsal ligament
•
Associated with increased risk (5%) of painful plantar scar
•
Typically used for revision neuroma resection
Review Recurrent neuroma
Definition
□
Bulbous enlargement of the neural stump (or secondary glioma)
□
Usually caused by inadequate proximal resection or failure of the nerve to retract after excision
□
Neural stump adheres to adjacent bone and soft tissue, causing a traction neuritis.
▪
Diagnosis
□
Localized pain and tenderness to palpation (Tinel sign) in web space of previous neuroma resection, at or proximal to metatarsal heads
□
Recurrent neuroma is likely if symptoms are localized and reproducible.
▪
Nonoperative treatment—similar to that for primary neuroma (see earlier)
▪
Operative treatment
□
Excision of the stump neuroma can be performed through another dorsal incision or through a plantar incision.
□
Plantar incision allows access to a very proximal location in which to place the resected neuroma stump.
•
Preferred approach for revision neuroma excision
□
The new stump should be transposed into muscle tissue if possible.
□
Success rate after excision of a recurrent or stump neuroma is 65%–75%.
Review tarsal tunnel syndrome
Definition
□
Compressive neuropathy of the tibial nerve within the fibroosseous tunnel posterior and inferior to the medial malleolus
□
Tarsal tunnel is bounded by the flexor retinaculum (laciniate ligament) superficially; the medial talus, medial calcaneus, and sustentaculum tali deeply; and the abductor hallucis inferiorly.
□
The tarsal tunnel also contains the tibialis posterior, the FHL and FDL tendons, the posterior tibial artery, the venae comitantes, and the numerous septa that subdivide the tunnel.
□
Reported causes of tarsal tunnel syndrome include tenosynovitis, engorged or varicose vessels, synovial or ganglion cysts, pigmented villonodular synovitis, nerve sheath tumors, lipomas, fracture of the sustentaculum tali or medial tubercle of the posterior process of the talus, middle facet tarsal coalition, and accessory muscles.
□
Systemic diseases such as diabetes mellitus, RA, and ankylosing spondylitis may have an indirect effect by causing inflammatory edema.
▪
Diagnosis
□
Symptoms of tarsal tunnel syndrome may be vague and misleading.
•
Include a burning sensation on the plantar surface of the foot and medial ankle and occasional sharp pains or paresthesias
•
“Irritable” tibial nerve must be ruled out.
•
Palpation should be performed along tibial nerve and branches distal to flexor retinaculum.
•
Prolonged standing, walking, or running can exacerbate the symptoms.
□
Physical examination
•
Percussion of the entire course of the distal tibial nerve and its branches should be performed.
•
Tinel sign, radiating pain or discomfort with continuous deep compression over the nerve, or diminished two-point discrimination may be elicited.
•
Sensory examination is usually unpredictable.
•
Hindfoot alignment should be assessed—pes planus may cause increased tension on the nerve.
•
Prior lateral closed-wedge osteotomy of the calcaneus can increase tension on nerve as well.
•
Wasting of the abductor hallucis or abductor digiti quinti may be seen if the medial or lateral plantar nerve is involved, respectively.
□
Diagnostic tests
•
Electrodiagnostic studies should be performed to help make the diagnosis or determine a different level of compression.
•
Sensory nerve conduction study findings are more commonly abnormal than those of motor nerve conduction studies.
•
Electromyography (EMG) abnormalities are less sensitive.
•
MRI may identify the presence of a mass-occupying lesion or middle facet subtalar coalition, which if present must be excised (Fig. 6.62).
•
Surgical decompression with mass excision results in more predictable symptomatic improvement compared with patients with tarsal tunnel syndrome and no associated mass.
•
Correlation with history and physical examination findings is essential.
□
Nonoperative treatment
•
Management should begin with conservative measures unless there is a suspicious mass or suspected malignancy.
•
Medications such as NSAIDs, vitamin B6, and tricyclic antidepressants are most commonly prescribed.
•
SSRIs and antiseizure medications (gabapentin, pregabalin) are also used.
•
Physical therapy may include stretching, massage, desensitization, and iontophoresis.
•
Orthoses to correct hindfoot valgus (medial heel wedge) play an important role as well.
•
In cases of acute inflammation or severe limitation because of pain, a brief course of a controlled ankle motion (CAM) walker boot or short-leg cast may be helpful.
□
Operative treatment
•
Space-occupying lesion should be excised, with concomitant nerve release.
•
If appropriate conservative management for 3 to 6 months is unsuccessful, surgical intervention is warranted.
•
Longitudinal incision is made over the course of the tibial nerve; it curves distally behind medial malleolus to the abductor musculature (Fig. 6.63)
•
The nerve is identified proximally, and the proximal investing fascia and flexor retinaculum are released.
•
Care must be taken to release the superficial and deep fascia of the abductor hallucis muscle.
•
Endoscopic tarsal tunnel release is not recommended.
•
Recurrence of tarsal tunnel syndrome is a challenging problem.
•
Incomplete release is the most common etiology; however, intrinsic nerve damage may play a role in recurrent symptoms.
•
Revision release may be of benefit if incomplete release is suspected, although results are often poor.
review anterior tarsal tunnel
Definition
□
Compressive neuropathy of the deep peroneal nerve in the fibroosseous tunnel formed by the Y-shaped inferior extensor retinaculum (Fig. 6.64)
□
The nerve divides into the lateral motor and the medial sensory branches within the tunnel and is accompanied by the dorsalis pedis artery.
□
Common causes of compression include tightly laced shoes, anterior osteophytes at the tibiotalar and TN articulations, a bony prominence associated with pes cavus deformity or fracture, ganglion cysts, and tendinitis of the EDL, EHL, or tibialis anterior (Fig. 6.65).
▪
Diagnosis
□
Patients present with burning pain and paresthesias along the medial second toe, lateral hallux, and first web space, or even vague dorsal foot pain.
□
Symptoms are often worse at night when the ankle assumes a plantar-flexed posture for sleep, and with wearing of shallow, laced shoes.
□
Physical examination
•
Decreased two-point discrimination, presence of Tinel sign along course of the deep peroneal nerve
•
Pain may be worse with plantar flexion of ankle as the nerve is stretched.
▪
Nonoperative treatment
□
Night splints, NSAIDs, diagnostic/therapeutic injections, shoe tongue padding, and footwear with loose lacing or alternative lacing techniques are the conservative approaches.
▪
Operative treatment
□
Surgical release involves incising the distal half of the inferior extensor retinaculum, releasing both branches of the nerve, excising bone spurs, and carefully repairing the bony capsule to avoid exposing the nerve to bleeding bone while protecting the dorsalis pedis artery.
□
Patients should understand that relief of the paresthesias and dysesthesias may take weeks or months.
sequelae of upper motor neuron disorders
Definition
□
Most commonly secondary to traumatic brain injury, stroke, and spinal cord injury
□
Disruption of the upper motor neuron pathways can lead to paralysis, muscular imbalance, and acquired spasticity, which ultimately may cause deformity of the foot and ankle.
□
Secondary problems include fixed contractures, calluses, pressure sores, hygiene issues, joint subluxation, shoewear difficulties, and dissatisfaction with physical appearance.
□
The most common deformity of the foot and ankle is equinovarus.
•
The equinus component is caused by overactivity of the gastrocnemius-soleus complex.
•
The varus is due to relative overactivity of the tibialis anterior and the tibialis posterior tendons with lesser contributions from the FHL and FDL.
•
The posterior tibial tendon is balanced by the peroneus brevis.
•
The anterior tibial tendon is balanced by the peroneus longus.
•
The anterior tibial tendon is balanced by the Achilles tendon complex in the sagittal plane.
▪
Nonoperative treatment
□
Early intervention with physical therapy, stretching and strengthening, and maintenance of joint ROM.
□
Other modalities include splinting, serial casting, oral muscle relaxants, phenol and lidocaine nerve blocks, and botulinum type A toxin injections.
•
Phenol blocks have a proven history, often have longer-lasting effects, and are less expensive than botulinum toxin injections.
•
Advantage of botulinum is ease of delivery—requires only an injection into the muscle belly rather than a precise injection around the motor nerve.
▪
Operative treatment
□
Surgery for acquired spasticity should be delayed at least 6 months after onset to allow for maximum recovery.
□
Equinus deformity is addressed with either an open Z-lengthening of the Achilles tendon or a percutaneous triple hemisection technique (Fig. 6.66).
□
Varus deformity is addressed with one of two procedures.
•
Tendon transfer to lateral cuneiform
•
Lateral cuneiform is center of rotation of the foot
•
Split anterior tibial tendon transfer (SPLATT) or total anterior tibial tendon
•
Posterior tibial tendon transfer is not the preferred surgical procedure in the setting of spasticity. If the varus deformity is fixed, lateral closed-wedge calcaneal osteotomy or subtalar fusion may be necessary.
□
Release of the toe flexors is often required secondary to a tenodesis effect as the ankle is brought into a plantigrade position.
Review Rheumatoid foot
Definition
□
Chronic symmetric polyarthropathy that most commonly manifests in the third and fourth decades and is more prevalent in women.
□
Synovitis causes ligament and capsular laxity and cartilage and bony erosion.
□
Vasculitis and soft tissue fragility are common, requiring diligent care of the soft tissues during nonoperative and operative management.
•
Use of immune-mediating pharmacologic therapies in the perioperative period should be discussed with a rheumatologist because of possible complications.
•
Most can be continued (prednisone, methotrexate, hydroxychloroquine), but the newer biologic agents (e.g., TNF antagonists) should be discontinued.
•
Most significant risk factor for development of a postoperative wound infection: history of previous wound infection
▪
Diagnosis
□
Foot involvement very common in RA
•
Forefoot more commonly involved than midfoot or hindfoot
□
Patients complain of forefoot swelling, poorly defined pain, and eventually deformity.
□
MTP joint pathophysiology
•
Chronic synovitis leads to incompetence of the joint capsules and collateral ligaments.
•
Toes subluxate or dislocate dorsally, deviate laterally into valgus, and develop hammering (Fig. 6.73).
•
Intrinsic muscles worsen the claw-toe deformity.
•
Plantar fat pad migrates distally and atrophies, causing metatarsalgia and painful keratoses.
•
As lesser toes deviate laterally, hallux valgus occurs and transfer metatarsalgia worsens.
□
Midfoot and hindfoot are less commonly and less severely involved in RA.
•
Significant midfoot/hindfoot arthrosis (TN joint characteristic)
•
Often results in a pes planovalgus deformity
•
Underlying cause of flatfoot deformity must be carefully assessed to determine whether it is midfoot driven or hindfoot driven.
•
Midfoot etiology—TMT joints subluxated, with a congruent hindfoot (Fig. 6.74)
•
Treatment—realignment midfoot arthrodesis
•
Hindfoot etiology—transverse tarsal and subtalar joints are subluxated, with a normal midfoot.
•
Treatment—triple arthrodesis
□
Tibiotalar joint also commonly involved—easily differentiated from osteoarthritis by lack of osteophyte formation, osteopenia, and symmetric joint space narrowing (Fig. 6.75)
•
Ankle arthrodesis is currently the treatment of choice, with ankle replacement emerging as a more reliable technique.
•
A tibiotalar and subtalar (tibiotalocalcaneal [TTC]) arthrodesis performed with an intramedullary nail risks a tibial stress fracture in patients with RA.
•
This complication is best treated conservatively with a cast.
•
Risks of wound complications after total ankle arthroplasty have been shown to be higher in patients with RA.
▪
Treatment
□
Nonoperative treatment
•
Rest, NSAIDs, immune-modulating drugs under the direction of a rheumatologist, toe taping, orthoses, and careful use of corticosteroid injections may help symptoms related to synovitis.
□
Operative treatment
•
Early (mild hallux valgus, mild claw toe without dislocation)
•
The new disease-modifying medication has resulted in a significant decrease in end-stage rheumatologic deformity. In patients with mild deformity without joint pain and with radiographic evidence of sparing of the joint space, joint preservation surgery as would be performed for nonautoimmune cases should be considered. Patients must be informed that the rate of recurrence may be higher and that late arthrodesis may be necessary secondary to the underlying disease process.
•
Late (in presence of severe deformity)—“rheumatoid forefoot reconstruction” (Hoffman procedure) (Fig. 6.76)
•
First MTP arthrodesis, lesser metatarsal head resection with pinning of the lesser MTP joints, and closed osteoclasis of the interphalangeal joints versus PIP arthroplasty
•
Silicone arthroplasty not recommended; complications are cock-up deformity, silicone synovitis, and osteolysis.
•
Accomplished through three well-placed longitudinal dorsal incisions (Fig. 6.77)
•
Extensor brevis tenotomy and Z-lengthening of the extensor longus tendons may be necessary.
•
Most common complication of forefoot arthroplasty is intractable plantar keratoses.
•
Midfoot, hindfoot, or ankle arthrodesis indicated as previously described
what is the rheumatoid Hoffman procedure?
midfoot OA treatment
Midfoot arthrodesis is the treatment of choice.
•
In the setting of deformity (flatfoot) the joints must be reduced into anatomic position to achieve a satisfactory result (realignment arthrodesis) (Fig. 6.81).
•
Medial column arthrodesis refers to fusion of both the NC and first TMT joints; it is occasionally required for a flatfoot deformity to stabilize the collapsed midfoot and restore the lateral–first TMT angle.
•
In situ fusion in the setting of a deformity will predictably lead to a poor result.
review subtalar bone block arthrodesis
Indicated for prior calcaneal fracture with loss of height
•
Normal calcaneal declination is ≈26 degrees
•
Results in anterior impingement, complaints of anterior ankle pain with ambulation in addition to hindfoot pain
•
Autograft or allograft bone block arthrodesis restores the height of the calcaneus.
•
Less successful at correcting residual hindfoot varus
What is a triple arthrodesis?
Arthrodesis of single joints leads to significant limitation in hindfoot inversion/eversion (affects TN > ST > CC).
•
Isolated TN fusion has a high rate of nonunion, and given the significant restriction of hindfoot motion from a TN fusion, an ST fusion is commonly performed in addition to ensure union without causing any incremental functional deficit.
•
Triple arthrodesis is also an appropriate option. If the CC joint is unaffected, it is more common to not include the CC joint in the arthrodesis (“medial double”) for a pes planovalgus deformity.
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Triple arthrodesis is usually performed to correct arthritis of the triple joint complex or rigid deformity that is not pes planovalgus
Review Peroneal tendon disorders
Most common disorders include tendinitis/tenosynovitis and tendon subluxation/dislocation, which often causes peroneus brevis degenerative tears.
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Diagnosis
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Acute or chronic localized swelling and tenderness over peroneal tendons
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Common cause of chronic pain following an ankle sprain or with chronic instability
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Associated with cavovarus foot deformity
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Peroneal subluxation or dislocation
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Caused by forced eversion and dorsiflexion leading to disruption of superior peroneal retinaculum (SPR)
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Pain and/or sensation of snapping in the retrofibular groove
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Often causes peroneus brevis degenerative tears
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Sudden dorsiflexion during downhill skiing is a common report.
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Plain radiographs may demonstrate a rim fracture of the lateral aspect of the distal fibula.
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Acute rupture of the peroneus longus tendon at or through a fracture of the os peroneum can occur.
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Radiographs show a retraction or fracture of the os peroneum.
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MRI may demonstrate displacement of peroneal tendons anterolateral to the retrofibular region.
FHL tendon pathology
Stenosing FHL tenosynovitis
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Usually seen in dancers on pointe and gymnasts
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Posterior ankle pain, triggering of the hallux interphalangeal joint, and pain with resisted hallux plantar flexion
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Stenosis occurs along course of FHL between the posterolateral and posteromedial tubercles of the talus.
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MRI is the diagnostic modality of choice.
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Fluid (high signal intensity) is noted surrounding the FHL at the level of the ankle joint (Fig. 6.97).
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Nonoperative treatment—activity modification, consideration of boot immobilization for short period of rest, NSAIDs
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Operative treatment—open (posteromedial approach) or arthroscopic FHL tenosynovectomy and release of the fascia
Review 5th metatarsal classification
Radiograph of jones fracture
Lisfranc Roman Arch
The second cuneiform and second metatarsal base are shaped like a keystone in the coronal plane. The Lisfranc joint is shaped like a Roman arch. The anatomy and stabilization by the Lisfranc ligament are important for support of the arch of the foot.
The second cuneiform and second metatarsal base are shaped like a keystone in the coronal plane. The Lisfranc joint is shaped like a Roman arch. The anatomy and stabilization by the Lisfranc ligament are important for support of the arch of the foot.
Normal Lisfranc radiograph
Normal anteroposterior weight-bearing radiograph demonstrating the alignment relationship between the base of the second metatarsal (arrow) and middle cuneiform (arrowhead). Any lateral deviation of the second metatarsal relative to the middle cuneiform is consistent with a Lisfranc disruption and must be treated operatively.
What is the fleck sign?
Patient with a Lisfranc injury identified by the fleck sign (arrow). In this case, the ligament itself remained intact and the injury occurred by avulsion of the ligament from the base of the second metatarsal. The function of the ligament is compromised, and operative intervention is indicated.
Review Hawkins talar fracture classification
The Hawkins classification of talar neck fractures remains useful because it is relatively simple, guides treatment, and has prognostic value.
(A) Type I fracture (minimally displaced).
(B) Type II fracture, with displacement of the subtalar joint.
(C) Type III fracture, with displacement of the subtalar and tibiotalar joints.
(D) The type IV fracture as described by Canale includes a talar neck fracture with displacement of the subtalar, tibiotalar, and talonavicular joints.
what is hawkins’ sign?
what is a snowboarder’s ankle?
Snowboarder’s ankle (fracture of the lateral process of the talus).
review the radiographic evaluation of calcaneal fractures:
The normal (A and C)
vs pathologic (G and H) radiographic anatomy of the calcaneus.
The lateral (A, E, and G) and Harris axial (C and H) views of the calcaneus are useful in assessing the shape and alignment of the calcaneus. (A and E) The lateral view allows for assessment of the posterior and middle facet positions as well as of calcaneal height (Böhler angle; E).
The Böhler angle is formed by drawing two lines. The first is drawn from the highest point on the anterior process to the highest point on the posterior facet. The second line is tangential to the superior edge of the tuberosity. The normal value of the Böhler angle is 25 to 40 degrees. (G) In the injured calcaneus, the Böhler angle is diminished, corresponding to the loss of height (flattening). (F) The critical angle of Gissane is the angle formed by the intersection of a line drawn along the dorsal aspect of the anterior process of the calcaneus and a line drawn along the dorsal slope of the posterior facet. The normal value of the Gissane angle is 120 to 145 degrees. (C and H) The axial view is useful for determining displacement of the tuberosity, varus angulation, fibular abutment, and displacement of the lateral wall.
Review the Sanders classification for calcaneal fractures
The Sanders classification is based on the fracture pattern through the posterior facet as seen on coronal CT scan. Type 1 fractures are nondisplaced. Type 2 fractures are two-part fractures of the posterior facet. Type 3 fractures are three-part fractures of the posterior facet. Type 4 fractures are highly comminuted, with four or more fragments to the posterior facet. (A and B) Type 2 and type 3 fractures are further classified according to the location of the fracture lines (A, B, and C), as shown. (C) This fracture would therefore be a Sanders type 3AC. The prognosis for calcaneus fractures worsens as the comminution of the posterior facet worsens.
