Chapter 92 - part 2 proximal phalanx Flashcards
What are the fracture configurations of the proximal phalanx?
1) proximal intraarticular osteochondral fractures (no histo confirmation that supports that is true OC)
(2) fractures involving the shaft or diaphyseal region of the proximal phalanx.
What are the types of fractures in each group?
- DOF
- POF (Type I and type II)
- short dorsal frontal
- Sagittal
3.1 long incomplete
3.2 non-displaced complete
3.3 displaced complete - frontal plane fractures biarticular
- palmar/plantar eminence
What are the most common cause of OC fractures?
trauma and hyperextension
What treatment is preferred for large chip fractures of the proximal phalanx?
Surgical removal using arthroscopy
What is the size of proximal fragment that can be embebed in the synovia?
2 mm and can heal without causing clinical symptoms
where is usualy the dorsoproximal fragment?
Dorsomedial
What percentage of racehorses return to use after arthroscopic surgery for osteochondral fractures of the proximal phalanx?
89% with 82% racing
Describe the surgical dorsal arthroscopy approch
DR - extension of the limb + distension of the joint (35mL)
Arthroscopic portal in proximolateral quadrant - arthro sleeve inserted perpndicular first to skin and after parallel to the articular surface of MCIII
What is the postoperative convalescence following arthroscopy OCD DOF?
6-12 weeks
Palmar/Plantar approach
skin incision with blade 11 proximal part of teh bulging capsule
arthroscopic sheath and conical obturator are inserted perpendicular to the skin initially and then are directed distad
fetlock 30-45º degree flexionat this time to facilitate passage between distal metacarpus/metatarsus and the proximal sesamoid bones
Bonilla VCOT 2019 described Standing Needle Arthroscopy of the Metacarpophalangeal and MetatarsophalangealJoint for Removal of Dorsal Osteochondral Fragmentation in 21 Horses. What is the size of the arthroscope?
1.2 mm needle arthroscope
What was the key finding about the return to racing post-diagnosis between non-surgically and surgically treated horses Ramzam 2021?
A) Non-surgically treated horses returned faster
B) Surgically treated horses returned faster
C) Both groups returned at the same rate
D) Neither group returned to racing
A) Non-surgically treated horses returned faster
The proximopalmar and proximoplantar osteochondral fractures can be classified in 2 types name them
Type I fractures when they are avulsed from the **axial, proximal, plantar or palmar rim of the proximal phalanx and are mostly articular.
Larger, abaxially located, partly articular osteochondral fragments have been categorized as Type II fractures.
Type II fractures extend distad 2 to 3 cm and contain minimal articular cartilage.**
Type I fractures have:
A. Lameness visible at higher speed (minimal)
B. Lameness visible all circumstances
C. Lamenes visible only if flexed
D. No lameness
A. Lameness visible at higher speed (minimal)
type II DO NOT PRODUCE LAMENESS
What type of proximal phalanx fractures are categorized as Type I fractures?
Avulsed from the axial, proximal, plantar or palmar rim
What is the success rate of horses returning to racing at or above their preoperative level after surgery for Type I fractures?
63%
How are Type I proximal plantar osteochondral fracture fragments usually accessed for surgical removal? describe approach
Via an arthroscopic approach through the plantar pouch
DR - flexed limb 30 to 45º - distension 35 mL - arthroscopic sheath and conical obturator
are inserted perpendicular to the skin initially and then are directed distad un the bulging capsule
Motorized resectors, radiofrequency cutting loupes or diode CO2 lase may be required
What is the incidence of Type II abaxial osteochondral proximal pal/pl fragments fractures in Standardbred yearlings?
Low (2.4% of 753 yearlings)
What is the convalescent care period for Type I fracture osteochondral proximal pal/pl fragments patients post-surgery?
6 to 12 weeks
P
Elevated oblique radiographic projection (D30Pr70L-PlDiMO) of the rear MTP region of a Standardbred pacer with a Type I (axial) osteochondral fracture (arrow) in the plantar pouch. These fragments need to be differentiated from Type II fractures on the abaxial corner of the proximal phalanx, many of which do not need surgery.
What is the best projection to differentiate Type I from type II osteochondral proximal palmar plantar fragments
the dorsal (20- to 30-degree) proximal (70-degree) medial—plantarodistal lateral oblique projection, highlight the plantar rim of the phalanx and the associated base of the proximal sesamoid bone
diagnosis
Figure 20.10 Osteochondral
fragmentation of the proximal plantar
aspect of the proximal phalanx. Lateral to
medial view (A) and elevated oblique view
(B) of plantar proximal phalanx fragment
diagnosis
Are type II proximal osteochondral fragmentation surgical?
No, Type II proximoplantar osteochondral fragments are located on the abaxial tuberosity of the proximal phalanx
and are** predominantly extraarticular = surgery rarely indicated**
If type II is giving clinical issues (extremly rare) what are the surgical options?
Nixon fx book
Arthrotomy A vertical 4 cm skin incision is made on the
abaxial surface of the fetlock joint at the level of the proximal
tuberosity of the proximal phalanx, a prominent portion of which is palpable dorsal to the palmar digital artery, vein, and nerve. The incision is continued through the distal part of the annular ligament of the fetlock and the joint capsule immediately distal to the collateral sesamoidean ligament and proximal to the proximal surface of the proximal phalanx. The fetlock is flexed and a retractor is used to expose the fracture. The fragment is
dissected free and removed.
**Lag screw fixation of a large fracture with two 3.5 mm cortical bone **screws also reported.
How do you remove the type I pal/pl fractures in yearlings during arhtroscopic approach?
A. Motorized resectors
B.. Diode or Co2 laser
C. Radiofrequency loupes
D. All of them
D. all of them
The fragments are dissected from the covering of synovial membrane and remnants of the attached short sesamoidean ligaments and removed
Would you go to surgery with a type II abaxial osteochondral fractures?
No usually extra-articular, very rare 2.4% prevalence, do not cause lameness and if associated to lameness place a 3.5 or 4.5 mm cortex screws inserted in lag fashion to achieve union.
Describe the dorsal frontal fractures
Most
involve fragmentation of the dorsal articular surface which may, or may
not, extend distally into the attachment of the fibrous joint capsule (usually extend only 2 to 5 cm from articular surface in the dorsolateral cortex of P1
Dorsal frontal fractures are usually complete or incomplete?
complete and minimally displaced
what is the ideal treatment?
Better repair with screw fixation in lag fashion one or two 3.5-mm cortex screws
Recover in soft bandage
What is the recovery after the lag screw placement for frontal fractures postop rest?
2 w complete stall rest followed by 6 weeks of hand walking
In the dorsal frontal fractures do you remove the implantes?
only where lysis or reaction has developed beneath the screw heads
Only if not displaced and healing occurs in 4 to 6 months
Favorable prognosis to return to race
what are the dyaphyseal fractures in P1?
- Sagittal
3.1 long incomplete
3.2 non-displaced complete
3.3 displaced complete - frontal plane fractures biarticular
P1 diaphyseal fractures are more in the FL or HL?
FL
SCB trauma and development of short fractures extending from sagittal groove is typical in race or Warmbloods?
Warmbloods
What is the prognosis for short diaphyseal fractures?
These are considered stress fractures, have significant variation in their configuration, and often are accompanied by osteoarthritis with a poor prognosis.
complete sagittal fractures exit axial or lateral or medial?
Complete fractures exit on either the lateral or, rarely, medial cortex of the proximal phalanx or enter the proximal interphalangeal joint (Figure 92-13, A)
Figure 92-13. (A) Dorsopalmar radiographic view of a complete nondisplaced fracture of the proximal phalanx commencing at the sagittal groove within the MCP joint and spiraling distally to enter the PIP joint. (B) Repair using 4.5-mm cortex screws placed in lag fashion through stab incisions.
Short sagittal fractures can be difficult to localize on routine dorsopalmar/-plantar radiographs and extend how much?
0.5 to 2 cm
when do you advise the owner to treat with screw fixation applying lag technique a short sagittal fracture?
If it doesn’t heal after 3 months of conservative therapy
short dorsal P1 fractures are more dorsally in FL or HL?
FL
when is transfixation device mandatory?
Disruption of weight-bearing support without an intact bony column is generally a contraindication to screw repair alone. In this case transfixation is required
If you place a 4.5 mm cortex screw how distal from the first one can you place the screw?
An additional more distal cortex screw can be placed 18 to 20 mm distal to the initial screw, depending on fracture length.
Long incomplete and nondisplaced fracture treatment?
For routine nondisplaced fractures, the proximal phalanx can be stabilized by inserting screws in lag fashion through stab incisions (see Figure 92-13, B)
In long incomplete and nondisplaced fracture what size should be the most proximal screw?
5.5 cortex screw for additional compression of the articular surface
How far from the sagittal groove should pass the proximal 5.5 mm cortex screw in long incomplete fractureS?
the proximal screw should pass within 5 mm of the most distal point of the sagittal groove of the proximal phalanx to provide maximum compression to the articular surface.
In long incomplete and nondisplaced fracture of P1 the first 5.5mm screw is placed 5 mm from SGroove and additional screws should be placed at what distance?
Additional screws are placed at intervals of 20 to 22 mm until the entire fracture line has been stabilized.
diagnosis
Figure 92-14. (A) Transverse computed tomographic (CT) view of an oblique frontal plane fracture of the proximal phalanx.
treatment?
Figure 92-14. (A) Transverse computed tomographic (CT) view of an oblique frontal plane fracture of the proximal phalanx. (B) Postoperative dorsopalmar radiographic view showing the direction the cortex screws were inserted in lag fashion. The CT image allowed the surgeon to orient the screws perpendicular to the fracture plane.