1st Ray Flashcards
what is the inferior surface of the 1st MT head grooved for?
articulation with the sesamoids
what are the sesamoids embedded in
the plantar plate
Sesamoids divide the plantar plate into what ligamentous regions?
- metatarsosesamoid ligaments (medial and lateral)
- phalangeosesamoid ligaments (medial and lateral)
- intersesamoid lig
what forms the sesamoid apparatus?
- tendon of FHB
- tendon of abductor hallucis
- conjoined tendon of adductor hallucis
- sesamoids
- plantar plate (includes sesamoid ligaments)
what bones does the 1st ray consist of
First MT and 1st cuneiform
what bones does the 1st ray articulate with
navicular, 2nd MT base and intermediate cuneiform
describe the motion of the 1st ray
uniaxial but triplanar
where does the axis of the 1st ray pass?
anterior, lateral, plantar to posterior, medial and dorsal
does the 1st ray provide for supination/pronation
NO, axis is directed opposite to the joints that provide for supination/pronation
the 1st ray is deviated:
- – from the sagittal plane
- – from frontal plane
- – from transverse plane
45
45
9
what type of motion occurs at the 1st ray
equal dorsiflexion/inversion and plantarflexion/eversion
what are some planal dominance of the 1st ray
- sagittal plane deformity
- dorsiflexed 1st ray
- congenital dorsiflexed 1st ray (metatarsus primus elevatus)
- acquired dorsiflexed
are typically bilateral and usually asymmetric
what are etiologies of a dorsiflexed 1st ray
- compensated RF varus
- FF supinatus
- abnormal STJ pronation (PL tendon looses its pull allowing the 1st ray to dorsiflex)
- spasm of the TA
- paresis or paralysis of the posterior tibial
- compensated FF varus
- iatrogenic
- trauma
what are clinical observations that are symptomatic of a dorsiflexed 1st ray?
- hallux limitus
- dorsal prominence
- hyperkeratotic lesions submet 2 and plantar aspect of the IPJ of the hallux
- during gait the STJ pronates and the calcaneus everts during propulsion
what are etiologies of a plantarflexed 1st ray
- congenital
- uncompensated RF varus
- FF valgus
- peroneal longus spasm
- paralysis of the TA and gastroc/soleus complex
- iatrogenic
what are clinical observations of a plantarflexed 1st ray
- hyperkeratosis submet 1 and 5
- compensation causing STJ supination
- acquired pes cavus foot type
plantarflexed 1st ray treatment
NSAIDs, analgesics
Orthotics (treat biomechanic abnormaility, 1st ray cut out to accommodate the 1st MT and sesamoids)
Surgical osteotomy
what is hallux limitis
- deformity of the 1st MPJ
- base of the proximal phalanx of the hallux is subluxed plantarly on the 1st MT head
- hallux is unable to move on the dorsum of the 1st ray
in younger patients with hallux limitus, you usually see
an exostosis
in older patients with hallux limitus, they usually present with
DJD of the articular surface
etiologies of hallux limitus
- hypermobility of the 1st ray
- excessively long 1st ray
- dorsiflexed 1st ray
- arthritis
- trauma
- osteomyelitis/septic joint
- paralysis of PL or spasm of TA
clinical features of hallux limitus
- 1st MT head is square in shape
- boney proliferation of the 1st MPJ
- compensation at the joint most distal AND most proximal
- tendonitis of the EHL
- decrease length of propulsion
- hyperkeratosis at the plantar aspect of the IPJ of the hallux
- trauma to the toenail
what is stage 1 of hallux limitus?
No DJD on x-ray
Normal ROM on non-weight bearing
No pain at end ROM
what is stage 2 of hallux limitus?
Pain at end ROM
Flat 1st MT head
Dorsal exostosis and periarticular lipping
what is stage 3 of hallux limitus
Crepitus on ROM
Joint space narrowing
Osteophyte formation
Increase flattening of the 1st MT head
what is stage 4 of hallux limitus
- obliteration
- osteophyte fragmentation
- minimum ROM/total ankylosis
what is the Drato, Oloff and Jacob Classification
Stage 1 - Pre-hallux limitus
Stage 2 - Structural adaptation
Stage 3 - Bone destruction
Stage 4 - End stage
what is functional hallux limitus
-limitation of the dorsiflexion of the 1st MPJ available during the stance phase of gait
is pain present upon examination of a functional hallux limitus
no (only a problem when ambulated)
what is required for treatment of a functional hallux limitus
- recognize etiological factors
- examine the LE and foot
- examine both weight-bearing and non weight-bearing ROM
- examine gait analysis
what is the conservative treatment for functional hallux limitus
NSAID
Steroid medication/oral or intra-articular injections
Orthoses - functional hallux limitus
Shoe gear - high toe box, steel shank, lower heel height, proper shoe size, avoid heel lifts
HAV deformity occurs in what planes?
transverse AND frontal plane
what kind of deformity is HAV
Progressive subluxation of the 1st MPJ during the propulsive phase of gait
what are the pathomechanics of HAV
- hypermobile 1st MT head inverts relative to the hallux
- a valgus subluxation occurs at the hallux at the 1st MPJ
- base of the proximal phalanx of the hallux subluxes laterally on the 1st MT head
- hallyx abducts on the 1st MT head
- the 1st ray subluxes at its base and the 1st MT adducts
Etiologies of HAV
- hypermobile 1st ray
- rheumatoid arthritis (system disease)
- neuromuscular disease
- iatrogenic
- abnormal STJ pronation
what occurs during Stage 1 of HAV deformity
- lateral subluxation of base of proximal phalanx
- minor lateral sesmoid displacement
lateral subluxation of base of proximal phalanx is only evident in what kind of x-ray
weight-bearing AP views
what occurs during Stage 2 of HAV deformity
- abduction deformity of the hallux
- hallux presses against 2nd toe
- medial bump
- sesmoids shift laterally
what occurs during Stage 3 of HAV deformity
- increased widening of the foot
- increase intermetatarsal angle
- tibial sesmoids are lateral to the 1st MT head
- mononeuritis is a common complaint
what occurs during Stage 4 of HAV deformity
- dislocation or major subluxation of the hallux
- overlapping 2nd digit
- frequently seen in conjunction with rheumatoid arthritis
- apropulsive gait
rate of development of HAV depends on
- extent or amount of abnormal STJ pronation
- size of the FF adducts angle
- extent of calcaneal eversion
- extent of STJ an MTJ subluxation
- extent of chronic inflammation at the 1st MPJ
what are other factors of HAV
- inclination angle of the STJ (, more calcaneal eversion with STJ pronation)
- excessive angle and base of gait
- absence of a propulsive period during stance phase
- obesity (may widen the base of gait)
- length of stride (if there is pronation during propulsion)
- hard flat terrain (can cause more abnormal pronation)
- abnormal fitting shoe gear
treatment of HAV
conservative - NSAIDs, steroid injection
- change in shoe gear*** (MUST DO THIS)
- orthoses
what is juvenile HAV deformity
- onset may occur at any age
- Root - “onset occurs when the child develops a propulsive gait (HAV is acquired)”
- a deformity exists in an individual 20 years-old or younger due to growth and remodeling of articular cartilage
factors associated with juvenile HAV
Metatarsus Adductus Pes Planus Ankle Equinus Hypermobile First Ray Neurological Disorders Juvenile Rheumatoid Arthritis
treatment of juvenile HAV
- conservative
- splints
- bunion shield
- shoe
- orthoses
what are the 2 surgical treatments for juvenile HAV
Delay surgery until skeletal maturity has occurred to avoid injury to the epiphyseal structures
Perform surgery before adaptive changes has created permanent alterations of structures
what is splay foot
- progressive abnormal transverse plane spreading of the MT
- an abnormally large intermetatarsal angle btwn the 1st and 2nd and the 4th and 5th MT
what are etiologies of spay foot
- abnormal STJ pronation
- subluxation of the rays at their basal joints which articulate with the navicular, cuboid and with each other
pronation in a splay foot can cause
- decrease transverse arch
- talus is displaced medially and plantarly
- if MT primus adducts and subluxation of the 5th ray is present, there is an increase in the angle btwn the 1st and 2nd MT and 4th and 5th MT
- the entire MT will become less stable to vertical GRF and ligaments become stretched
what are clinical features of Splay foot
- wide FF
- prominent HAV and Tailors bunion
- digital deformities
what is the normal IM angle of MT 1 and 2
7-9
what is the normal IM angle of MT 4and 5
9
what will be present in a radiograph of a splay foot
- increase IM angle btwn 1,2 and 4,5
- 5th ray is more dorsiflexed with lateral bowing of the shaft
treatment of Spay foot
Conservative Shoes Orthoses to correct pronation Surgical Correction of associated problems (HAV, Tailors bunion)
Metatarsus Primus Adductus deformity is in what plane
-transverse plane deformity of the 1st ray
what is Metatarsus Primus Adductus deformity
1st MT and cuneiform gradually sublux away from the 2nd ray
etiologies of Metatarsus Primus Adductus deformity
(same as splay foot)
- abnormal STJ pronation
- subluxation of the rays at their basal joints which articulate with the navicular, cuboid and with each other
what is the 5th ray composed of
5th MT only
what type of motion occurs at the 5th ray
uniaxial, triplanar
where does the axis of the 5th ray pass through
proximal,plantar,lateral to dorsal,distal, medial
5th ray deviates primarily from what planes
sagittal and frontal (only slight deviation from the transverse plane)
what type of motion does the 5th ray provide
supination + pronation
Tailors Bunion deformity occurs in what plane
transverse plane
what can be seen present with a Tailor’s bunion
- 5th MT head develops a lateral prominence
- isolated deformity or part of a splay foot
- inflammed bursa
Etiologies of a Tailors Bunion
Abnormal STJ pronation plus uncompensated varus deformity
Abnormal STJ pronation plus hypermobile 5th Ray
Congenital dorsiflexed 5th Ray (not curved laterally on x-ray)
Congenital plantarflexed 5th Ray
Idiopathic (absence of the adductus hallucis muscle)
clinical features of Tailor’s Bunion
- prominent 5th MT head
- possible overlying adventitious bursa formation of the 5th MT head
- hyperkeratotic lesion submet 5
- prominence 5th MT base
radiographic features of Tailor’s Bunion
- increased IM angle btwn 4th and 5th MT
- increased lateral deviation angle
- large dumbell shaped 5th MT head
- arthritic changes leading to exostosis formation at the 5th MPJ
- rotoation of the lateral plantar tubercle to the lateral position
treatment of Tailor’s Bunion
Conservative
NSAID, Steroid injection
Shoes
Assessment of underlying medical conditions which may aggravate the condition
Tapping or padding on painful boney prominence
Debridement of hyperkeratotic lesions
central ray consist of what rays
rays 2nd and 3rd metatarsals and cunieforms and 4th MT only
rays 2-4 provide —- plane motion
sagittal
the 3rd ray has less ——- than the 2nd and 4th ray
dorsal excursion
pathomechanics of 1st ray deformities
- isolated structural deformities
- a long 1st MT or long proximal phalanx can cause hallux limitus, digital deformities and callus
- a short 1st MT-brachymetatarsal can cause callus, HAV and digital deformities
what are central ray deformities associated with sagittal plane relationship?
Metatarsal equinus-associated with Pes cavus
Metatarsal abductus/adductus-usually mechanically induced synovitis or rheumatoid arthritis
Metatarsal dislocation-radiographs confirm diagnosis
Central Ray deformities associated with abnormal metatarsal head structure
Hypertrophy of the plantar condyles-Lateral condyle most common occurrence
Avascular Necrosis
what is avascular necrosis
abnormal blood supply to the bone causing a local infarct
where is avascular necrosis commonly seen
in the 2nd met head (Freiburg’s disease)
avascular necrosis is caused by
repetitive microtrauma or major trauma to the growth plate
where is the pain and deformity with avascular necrosis
met head
avascular necrosis is clinically associated with
- history of trauma
- localized pain at leve of joint
- flat MT head or proximal phalanx base
- punctate keratosis
General Treatment for Central MT Ray Deformity
Conservative
Pain meds, debridement of keratotic lesions, padding of keratotic lesions and boney prominence, orthoses (functional or accommodative) and shoe therapy
Surgical (high failure rate for certain procedures)
Osteotomy, proximal or distal - to elevate metatarsal head
Plantar condylectomy, partial or total metatarsal head resection, and arthroplasty of the involved joint
what is predislocation syndrome
- painful instability of the lesser MPJ
- dislocation of the proximal phalangeal base of the MT head
- is progressive
why does predislocation syndrome occur
due to weakening of the periarticular structure that stabilize the MPJ (plantar plate)
what are signs of predislocation syndrome
- medial or lateral deviation of digit (medial most common)
- hammertoe deformity - dorsal corn is not present
- 2nd MPJ is affected mot often
what are clinical presentations of predislocation syndrome
Acute or chronic focal plantar pain Pain on ambulation/subsides at rest Swelling plantar aspect of the foot Patient relates “Walking on Stones” History of trauma/increase activity level Patient was given a diagnosis of Neuroma
what is Stage 1 of predislocation syndrome
mild edema plantar, dorsiflexed MPJ, extreme tenderness on manipulation, no anatomical misalignment
what is Stage 2 of predislocation syndrome
moderate edema, deviation of affected digit on radiograph and clinically
what is Stage 3 of predislocation syndrome
moderate edema of the entire circumference of the MPJ and extending to digit, more pronounced deviation, possible subluxation
what is another name for vertical stress test
Thompson and Hamilton
how is a vertical stress test performed
Foot is in neutral stance
Metatarsal head is stabilized between two fingers, the other hand grabs the base of the proximal phalanx
Vertical force is applied to the base of the proximal phalanx in a dorsal direction
Positive test-when the proximal phalanx can be translocated 2mm dorsally above the metatarsal head
what are differential diagnosis for predislocation syndrome
DJD of MPJ Avascular Necrosis - xray Rheumatoid Arthritis Neuromuscular Dysfunction Neuroma – rule out using ultrasound
pathomechanics of predislocation syndrome
-any structural or biomechanical deformity that increases loading forces within the FF and results in inflammation of the plantar plate
examples of pathomechanics of predislocation syndrome
Long 2nd metatarsal HAV High Heeled shoes Heel lifts Hypermobility Metatarsus Primus Elevatus Ehlers - Danlos syndrome
what is the plantar plate
fibrocartilage thickening of the 1st MPJ capsule
what is the plantar plate attached to
- firmly attached to the base of the proximal phalanx, loosely attached to the MT head
- major distal attachment to the plantar fascia
- attachment to the deep transverse MT ligament, MPJ collateral lig, interosseous, and lumbricales muscles
what is the function of the plantar plate
stabilizes the lesser MPJ plantarly
diagnosis modality of the plantar plate
- x-ray - lateral and DP (MT length)
- arthrogram - evaluate integrity of the joint capsule. Inject contrast dye dorsally
Opaque if joint capsule is ruptured, if it leaks outside the joint capsule, the collateral ligaments are ruptured - MRI
conservative treatment of fractured plantar plate
Steroid (oral and injectable)
NSAIDS
Metatarsal sling pad/taping
Longitudinal Metatarsal Pad with a lesser MPJ cut out
Shoe gear - extra depth shoes with a rocker bottom and a steel shank
Physical Therapy
what is the goal of performing a plantar plate surgery
- release the periarticular contracture and decompression of the MPJ to reestablish alignment of the digit
- restore plantar plate function and release dorsally contracted structures
what procedures can be performed at the plantar plate
Primary repair of plantar plate
Tendon Transfer (EDB)
Soft tissue and Osseous-resection of Proximal Phalanx base, Partial Metatarsal head resection, Oblique osteotomy of metatarsal head and neck
Arthrodesis (fusion) of the PIPJ
Extensor hood release
Dorsal, medial, and lateral MPJ capsule release
K-wire driven across the MPJ for 5 to 7 weeks
name sagittal plane digital deformities
- hammer toe
- claw toe
- mallet toe
- hallux extensus
- hallux flexus
name transverse plane digital deformities
- digiti abductus
- digiti adductus
- hallux interphalngeus
name frontal plane digital deformities
-curly toe/varus
name combination digital deformities
adductovarus toe
what are the primary muscles involved in digital functions
- Intrinsic - lumbricales, quadratus plantae, interossei, EDB, FDB
- extinsic - FDL, EDL, FHL, EHL
describe a hammer toe
- Dorsiflexed position of the proximal phalanx at the MPJ
- Plantarflexed position of the middle phalanx at the PIPJ and an extended position of the distal phalanx at the DIPJ
describe a claw toe
Dorsiflexed position of the proximal phalanx at the MPJ and plantarflexed position of both the middle and distal phalanx at the PIPJ and DIPJ
describe a mallet toe
Plantarflexed position only of the distal phalanx at the DIPJ
what is hallux extensus
Extended or dorsiflexed position of the distal phalanx of the hallux at the IPJ
what is hallux flexus
Mild plantarflexed position of the distal phalanx of the hallux of the IPJ and mild dorsiflexion at the MPJ
what is hammer digit syndrome (HDS)
loss of normal muscle balance
how can a HDS exist as
a classic hammer or claw toe deformity
etiologies of HDS
Flexor Stabilization (most common) FDL & FDB gains a mechanical advantage over the interossei during stance phase of gait
HDS causes
- flexible/hypermobile foot
- FF valgus
- interosseous muscle weakness
- adductovarus deformity of the 4th and 5th toe
flexor substitution is a rare cause of
HDS
what is flexor substitution
substitution of the deep posterior and lateral components of the leg for the triceps surae during late stance phase of gait. The flexors will fire early and longer causing severe digital contractions with no adductovarus component
what is the cause of triceps weakness
neurogenic or iatrogenic
what is extensor substitution
-mechanical advantage of the extensors over the lumbricales during the swing phase of gait
extensors substitution can cause what deformities
hammer toe
claw toe
extensor substitution can be seen with
- ankle and MT equinus
- lumbricale wakness
- EDL spasticity
where can extensor substitution be seen
at the hallux and lesser digits
etiologies of hammer toe deformity
Plantarflexed deformity of the metatarsal Loss of lumbricles function Imbalance between medial and lateral interossei muscle Flaccid paralysis of EDB and EDL Brachymetatarsal Forefoot valgus Abduction pressure from the hallus Subluxed pronated 5th metatarsal Trauma to MPJ
etiologies of claw toe deformity
Forefoot adductus Congenital plantarflexed 1st Ray Inflammatory arthritis Contracture or spasm of the long and short flexors Gastrocnemius pareis Supinated forefoot deformity Forefoot equinus
Clinical fetures of HDS
Bursitis of the involved IPJ
Flexor plate dislocation
MTJ limitus, abductus, adductus
Rotation of a digit, long and short digits
Ulceration, nail pathology, subungual exostosis, neuritis
Kelikian push-up test - assessing the degree of rigidity of the HDS deformity
when does hallux extensus usually occur
secondary to hallux limitus
what is hallux extensus
Pain present on plantar aspect of IPJ hallux, plantar keratoma at IPJ, distal subungual exostosis, nail pathology
what foot types is hallux extensus associated with
Compensated forefoot varus
Forefoot valgus
Compensated gastrocnemius equines
what is hallux interphalangeus
The distal phalanx of the hallux is deviated away from the midline of the body
when can hallux interphalangeus occur
isolated or with a HAV deformity
what can aggravate hallux interphalangeus
valgus rotation of the hallux
where can digital adductus occur
at the MPJ, PIPJ or DIPJ
congenital hallux interphalangeus affects the
distal phalanx
