Ch 55 carpus, metacarpus and digits Flashcards

Question

sesamoid disease causes?

Answer 1

causes of sesamoid disease - trauma, - congenital disorders of ossification, - degenerative joint diseases from abnormal forces, - osteonecrosis secondary to vascular compromise dogs that present with thoracic limb lameness will have additional orthopedic conditions that could be the primary cause of the lameness because sesamoid disease is often subclinical STUDY: observational study comparing the long-term outcomes of a group of dogs treated conservatively versus surgically - Better clincal results and less OA change in those threated conservatively with rest - try conservative management first are fair for the level of evidence. - Surgery is limited to removal

Answer 2

Hyperextension causes: fall from heights, jumps, no trauma i.e. immune-mediated arthropathies

Answer 3

- results in loss of palmar support and hyperextension of the carpus. - Both medial and lateral collateral ligaments have a role in preventing carpal hyperextension. - Luxation of the carpus may occur at the proximal (antebrachiocarpal), middle carpal, or distal (carpometacarpal) level - antebrachiocarpal joint was injured in 50% of the cats Dx - routine lateral and dorsopalmar views, stress lateral (with the carpus in extension) and medial and dorsopalmar stress - Conservative management of carpal hyperextension is rarely successful - Pancarpal or partial carpal arthrodesis is generally accepted as the best treatment

Answer 4

If grade 1 or grade 2 sprain of the radial or ulnar collateral ligaments is present, palpable instability is unlikely. Rupture (grade 3 sprain) of the ligament leads to instability - confirmed by joint space widening on stress views. Enthesophyte formation is reported in chronic sprains - Conservative treatment of grade 1 and 2 sprains has been successful in both racing Greyhounds and pet > true incidence of success is unknown - Suturing the torn ligament and splinting can primarily repair radial and ulnar collateral ligament ruptures - Most authors recommend a synthetic suture stabilization - drill holes, bone anchors, or screws placed at the origin and insertion of the collateral ligaments - palmar splints or casts are recommended for 4 to 8 weeks - chronic collateral ligament instability, a pancarpal arthrodesis

Answer 5

27% in the forelimb - 79% of which are distal - 69% are medial - 50% instability | one retrospective study of 98 cases

Answer 6

occur most frequently on the medial aspect of the limb, - loss of soft tissue support may include the short radial collateral ligament, along with the radial styloid process - reconstruction using bone anchors or arthrodesis tx - surgical debridement and lavage, appropriate bandages and splints, topical antimicrobials, and oral antibiotics. - instability, decision regarding immediate versus delayed stabilization while the open wounds are managed - immediate stabilization can be performed using internal or external fixation - delayed wound healing and implant-associated infection - unknown if better to delay stabilisation or not

Answer 7

- deep digital flexor tendon is usually the affected (palmar to the superficial flexor from the level of the metacarpophalangeal joint) - radiographs demonstrating dorsal deviation of the distal phalanx - treat as contaminated wound - positioning the digits in flexion during repair - carpus and toes are maintained in slight flexion, External coaptation for 6 to 8 weeks - Immobilization can decrease the function of flexor tendons. - In vitro, platelet-rich plasma enhanced maximum breaking strength and stiffness after suturing

Answer 8

Hyperextension of the distal interphalangeal joint. When weightbearing, the claw will appear elevated

Answer 9

indications - collateral ligament injury, - hyperextension injury with or without luxation, - shearing injury, - articular fracture that is not repairable, - severe OA, - immune-mediated arthritis leading to joint collapse or pain, - neurogenic injury that affects only the distal limb pancarpal versus a partial pancarpal indicated when the antebrachiocarpal joint is involved or when middle carpal or carpometacarpal joint involvement causes damage to the accessory carpal ligaments, the palmar fibrocartilage, and the palmar ligaments. STUDY: low case numbers, different surgical procedures within the groups, and bilateral treatment of some dogs were confounding factors, but function was not very different between the two surgery groups

Answer 10

10-12 degrees

Answer 11

- DCP or LC-DCP - Hybrid-DCP - Single- or double-stepped hybrid arthrodesis plate (VOI) - CastLess plate (Orthomed) (20% less risk of MC fracture)

Answer 12

- antebrachiocarpal joint (gait cycle) range is from 10 - 47 degrees of extension - **palmar surface** is the tension surface > major disadvantage of a difficult approach Medial pancarpal arthrodesis has been reported - dorsal approach - expose distal third of the radius, the carpus, and the length of metacarpal III. The extensor carpi radialis muscle tendon to metacarpals II and III is severed - articular cartilage is removed > cartilage to the level of subchondral bone - cancellous autograft or allograft - plate: one screw engages the intermedioradial carpal bone and the four distal screws - using a splint to help avoid implant complications is refuted in both clinical and biomechanical studies. These studies indicate that splinting is the cause of complications, with no evidence of protecting the constructs

Answer 13

not standardized between studies Comparison of complications across publications is difficult due to differences in case management, reporting classification systems and follow-up time **7% to 50%.** - mechanical lameness can persist - screw loosening, - implant breakage, - infection, - metacarpal bone fracture, - implant sensitivity, - incomplete arthrodesis, - continual gait abnormality associated with splint common (minor)

Answer 14

Tanner MC, Fischer C, Schmidmaier G, Haubruck P. Evidencebased uncertainty: do implant-related properties of titanium reduce the susceptibility to perioperative infections in clinical fracture management? A systematic review. Infection 2021;49 (05):813–821

Answer 15

- MC screws no more than 40% diameter - Plate spans more that 50% length of MCIII - Additional support of IM pins (controversial) - Ensuring proper alignment of distal limb - Adequate removal of articular cartilage

Answer 16

- Review: clinical/biomechanical studies of plates demonstrates that despite differences biomechanically, all plates can be used successfully. - Comparison 2.7/3.5 mm hybrid and the 3.5 mm DCP > significant difference between bending moments at failure, favoring the hybrid - percentage of bone diameter removed for screw placement is important CastLess vs hybrid (finite element model). - bone distal to the last metacarpal screw had the greatest stress - CastLess plate had 20% less risk of metacarpal fracture than the hybrid - no significant differences in the stiffness - failure rarely due to plate breakage and usually due to technical mistakes locking alps vs hybrid - no difference Pancarpal specialty plates stepped hybrid plates designed with a smaller metacarpal screw, a long version best angle of 10 to 12 degrees of extension without manual bending CastLess plate is designed with the distal screws engaging metacarpals III and IV at an angle of 8 degrees.

Answer 17

Engage MC III and IV at an angle of 8 degrees

Answer 18

- STUDY: plate, with or without crossed Kwire, demonstrated significant increase in yield load with crossed Kwires, but stiffness and failure loads were not different > appears to be no reason to increase stiffness for PCA plates - transarticular linear or circular ESF Cats - Fixation methods were variable - complication rate was 35% (comparable with canine - long-term outcomes were similar to those of canines

Answer 19

- 40% with hybrid plate at mean 288d - 46.2% with CastLess plate at mean 209d Bony bridging intercarpal and carpometacarpal > 9 - 12 wk Radiocarpal > 17 - 30 wks

Answer 20

- appropriate for injuries of the intercarpal and carpometacarpal joints - may preserve some function of the antebrachiocarpal joint and may improve long-term outcomes - Published case series have been managed using plates, cross-pins, or pins - case series PCA vs ParCA reported only 50% satisfactory ParCA versus 70% for PCA - STUDY: comparison CastLess and a T-plate demonstrated similar results Sx - first screw placed intermedioradial carpal bone, next screw most distal plate hole on metacarpal III - ensure place the plate distal enough to avoid contact with the distal radius when joint is extended - intermedioradial carpal bone screws too long; otherwise may interfere with palmar ligaments - cross-pin technique: metacarpal II to the ulnar carpal bone and then another pin from the intermedioradial carpal bone to metacarpal V - clinical studies indicate that external coaptation may not be necessary with any plating techniques

Answer 21

- location (antebrachiocarpal, middle carpal, or carpometacarpal) is considered severe and will likely require a pancarpal arthrodesis - Complete luxations are uncommon compared with subluxations

Answer 22

36 dogs with radiographic osteoarthritis were identified, but only 9 of those dogs presented with osteoarthritis as a clinical problem - were clinical were more likely to have swelling over the affected digits. - Metacarpals IV and V were affected more often - periosteal reaction is extensive (up to 33% of the length of the metacarpal bone) > smooth with no destructive lesions - distinguish from primary bone neoplasia of a metacarpal bone

Answer 23

Carpal hyperextension, hyperflexion or flexural deformity in young puppies. - Dobermans and Shar-Peis overrepresented - Associated with over or under supplemented diets and concrete floors with little exercise room - Recovery in 1-4wk with appropriate diet, controlled exercise program and good traction flooring - splint or bandage, no evidence suggests that any support is needed | 65% of the dogs recovered within 2 weeks

Answer 24

- **SCC** 35%, subungual epithelium (greater metastatic potential than in other parts of the body, amputation 1yr MST 76%)) - **melanoma** 17.3% (MST 322 days) - **STS** 9.7% (2 showing metastatic dz) - **MCT** 6.7% (1-year MST 75%)

Answer 25

- **SCC** 23.8% (MST 73 days) - FSA - Adenocarcinoma - OSA - MCT - HSA Prognosis was poor for SCC and for adenocarcinoma

Answer 26

- Inflammatory lesions (26.7%), and neoplastic lesions 72.3% - Radiographic osteolysis seen in both malignant and benign neoplasms, most common in dogs with SCC - Pulmonary metastatic: melanoma (32%) squamous cell carcinoma (13%). - Digit amputation > recommended tx

Answer 27

indications: - chronic sprains or luxations, - intra-articular fractures, - chronic osteomyelitis - osteoarthritis - neoplasms or degloving/shearing wounds entire digit, an inverted-Y incision is made

Answer 28

Nearly all lesions will recur in Greyhounds, other breeds do not have recurrence after surgical excision

Answer 29

Unknown! - Possible trauma, drugs, bone infection - Reported in intermedioradial carpal bone and accessory carpal bone - PCA resolved pain and lameness

Answer 30

retrospective survey methylprednisolone and bupivacaine (IMPB) or conservative management with nonsteroidal anti-inflammatories and rest (CMNR) One week after IMPB, 52/58 (89.7%) dogs demonstrated resolution of lameness compared with 1 week of CMNR, 0/18 (P < 0.001 Dogs presenting with the sesamoid disease had comorbidities 65.4% of cases. Elbow disease was the most common comorbidity 29/78 (37.2%). no difference in lameness or client satisfaction between treatment groups at long-term follow-up (12 months). Dogs that had a recurrence of lameness had a 50% likelihood of responding to a second injection (median 54 days) also to confirm the diagnosis of sesamoid disease. aetiology of sesamoid disease in Rottweilers is mostly speculative. Proposed aetiologies include anomalous congenital ossification (bipartite), degenerative joint disease, osteochondrosis, trauma and flat-footed confirmation pain on flexion and palpation of the affected joints, joint effusion and soft tissue swelling, with subtle lameness radiographic changes do not correlate with affected digits Mathews et al. concluded that sesamoidectomy was associated with a greater progression of degenerative joint disease compared with conservative management

Answer 31

concerns in the literature regarding the deleterious effects of intra-articular local anaesthetics. prompted studies into chondrocyte death in vivo and in vitro environments. The studies typically involve high concentrations of bupivacaine in contact with in vitro cell cultures of chondrocytes incubated for long periods. - Barry et al: intra-articular concentration of bupivacaine rapidly dilutes over a 30-min period, suggesting that rapid dissolution of bupivacaine is unlikely to result in a deleterious effect on chondrocytes. - Contrary to these findings, combinations of methylprednisolone/1.0% lidocaine, triamcinolone/1.0% lidocaine and triamcinolone/0.0625% bupivacaine lowered the subjective chondrocyte viability scores in another in vivo study.

Answer 32

antebrachiometacarpal arthrodesis. Excision of all carpal bones, except the accessory carpal bone, was done, either because of persistent infection or to allow the manus to be arthrodesed in a functional position All five arthrodeses achieved complete osseous union within 4–67 weeks. Infection necessitated plate removal in 4/5 dogs had acceptable limb function at the time of the final evaluation

Answer 33

working dogs (worth) - Following arthrodesis, 6/12 (50%) dogs could perform duties as before surgery. A further four (33%) dogs could perform most former duties. - Post-operative complications occurred in 50% of dogs, but in only one case affected the eventual outcome - 20% infection

Answer 34

Implant (55%) removal after partial carpal arthrodesis was frequent and was commonly indicated due to pin and wire fixation or plate implant interference. This study may impact how we prepare clients for potential post-operative complications and implant removal when recommending partial carpal arthrodesis. 75% return to function

Answer 35

Damage to the FCU tendon were located at the ulnar head on ultrasonographic and intraoperative examinations immobilized by a type I external skeletal fixation for 6 weeks No recurrence of carpal hyperextension was observed over 36 months after surgery hyperextension due to disruption of the palmar ligament or some kind of tendon injury, the only tendon involved in stability during extension of the carpus is that of the flexor carpi ulnaris muscle (FCU) FCU - humeral head (caput humerale), medial epicondyle of the humerus ulnar head (caputulnare), proximomedial ulna - both muscle bellies insert onto the accessory carpal bone

Answer 36

Retrospective. 22. comparison of ALPS titanium hybrid and steel Hybrid-DCP for pancarpal arthrodesis + coaptation at surgeon discretion - ALPS → higher metacarpal coverage (74%) vs HDCP (56.5%) - complications: major: ALPS 4/15 (26.6%), HDCP (4/14 (28.6%) - ALPS: SSI, plate fracture, sx site dehiscence - HDCP: screw loosening, SSI 30-35% minor: ALPS 3/15 (20%), HDCP (35.7%) - no significant difference - outcome: ALPS → 66.7% full function, 25% acceptable, 8.33% unacceptable HDCP → 72.7% full, 9.1% acceptable, 18.1% unacceptable - no significant difference between groups lower bending stiffness and strength ALPS > titanium having a lower modulus of elasticity compared with stainless steel. Healing of PCA is reported to plateau after 84 days (12 weeks)

Answer 37

retrospective, All dogs responded to conservative management, with all dogs regaining full extension of the antebrachiocarpal joint and ambulating normally at the time of the final visit For dogs with grade 3 severity, however, mean time to recovery was significantly shorter for dogs treated with rest and bandaging than for dogs treated with rest alone.

Answer 38

Feline carpal injuries only have a single short radial collateral ligament > antebrachiocarpal subluxation is possible with rupture of the dorsal joint capsule and short radial collateral ligament alone. pancarpal arthrodesis > reduce the height of jumping and to increase reluctance to climb. reduced pronation and supination Evidence base: grade III or IV, most retrospective case series Always perform stress views primary repair with rigid fixation as a first-line treatment (more favourable outcome) rather than PCA

Answer 39

The proximal row of carpal bones translate and rotate independently from the ulna in the cat during pronation of the antebrachium. This may have future implications in the diagnosis and management of feline carpal injuries involving the antebrachiocarpal joint. feline carpal joint is not purely a ginglymus because movements other than flexion and extension at the level of the antebrachiocarpal joint may occur PCA > important to understand the extent to which this surgical procedure may compromise supination and pronation.

Answer 40

Prospective descriptive study. Study population: Cadavers from dogs weighing more than 20 kg Arthrography improved the capabilities of MRI but not of CT for visualization of the canine carpal ligaments. Magnetic resonance arthrography was particularly useful for evaluation of the stabilizers of the antebrachiocarpal joint. Clinical significance: 3 Tesla MRA and MRI allow excellent visualization of the ligamentous morphology and may be helpful in the diagnostic process of carpal sprains in dogs. Preliminary results