Canine Limb Orthopedics

Carpus, Elbow, Humerus

Puppy Carpal Laxity Syndrome (PCLS)

 Age‑specific developmental instability (6‑16 wk); two sub‑types (hyper‑ vs. hypo‑extension).  Exam focus: splint protocol (2 weeks, re‑form every 2‑3 days) and when surgical tenotomy or pancarpal arthrodesis is indicated.

Accessory Carpal Bone Fracture in Greyhounds

 Breed‑predominant (≈80 % right‑carpus); classification I‑V with “sprain‑avulsion” subtypes.  Exam point: large fragments → surgical repair; small fragments often heal with a > 90 % return to racing.

Metacarpophalangeal (MCP) Sesamoid Disease

Typical in racing Greyhounds, Rottweilers, Labradors. Key sign: pain on palpation of MCP joint without obvious fracture; radiographs are the primary diagnostic tool.  Treatment contrast: conservative rest vs. palmar sesamoid excision.

Indications for rest → mild lameness, no major fragment, low‑impact dog.

Indications for surgery → persistent pain > 4 weeks, large/displaced fragment, high‑performance dog.

Paw‑Pad Corns (Keratomas) in Greyhounds

 Hyper‑keratotic circular lesions on digital pads; high recurrence (>50 %).

 Exam emphasis: surgical excision is the mainstay, but adjuncts (laser, cryo) have limited success; prognosis is guarded because of recurrence.

Radial/Ulnar Asynchronous Growth (Radial or Ulnar Shortening)

A mismatch in length between the radius and ulna caused by loss of synchronous growth of their physes. It manifests as either radial shortening or ulnar shortening in growing dogs. 

Diagnosis relies on radiographs/CT showing mismatched bone lengths.  

When is conservative management appropriate? (R/U asynchronous growth)

In mild cases (≤ 10 % length discrepancy) with little angular deformity and no elbow incongruity; activity restriction and periodic re‑checks are sufficient.

Which surgical option is preferred for a juvenile dog with ulnar shortening?

Dynamic ulnar ostectomy – a large segment of the ulna is removed, periosteum excised, and a fat graft or intramedullary pin may be placed to prevent early bridging, allowing proximal migration of the ulna.

What is the adult‑dog counterpart to dynamic ulnar ostectomy?

Ulnar shortening osteotomy – a segmental (often wedge) resection of the ulna with internal plate fixation to match the radius length.

When would radial lengthening be chosen over ulnar shortening?

In severe radial shortening where shortening the ulna would compromise limb function; distraction osteogenesis of the radius using an external fixator is performed.

Monteggia Fracture (proximal ulna + radial‑head luxation)

Classic pattern of ulnar fracture with radial‑head dislocation; classification I‑IV. Exam focus: repair with intramedullary pin or plate ± radioulnar screw and the need to remove implants after 4‑6 weeks.

Incomplete Ossification of the Humeral Condyle (IOHC/HIF)

Developmental failure of the lateral/medial humeral ossification centres (fusion normally 8‑12 wk). Unique because it is diagnosed best with CT and most dogs are prophylactically treated with a trans‑condylar screw + plate rather than waiting for a fracture.  Exam may ask for breed predisposition (Spaniels, French Bulldog) and the rationale for prophylaxis.

Distal Humeral Condyle Fractures (Lateral Condyle)

Often linked to IOHC; usually Salter‑Harris IV. Key exam point: lag screw fixation ± K‑wire; untreated leads to medial elbow subluxation.

Carpal Arthrodesis (Pancarpal vs. Partial)

Decision‑making based on which carpal joints are involved (ABCJ, middle, carpometacarpal). Exam often tests the functional standing angle (10‑12° extension) and differences in motion preservation (partial retains ~85 % carpal motion).

Elbow Luxation – Traumatic vs. Congenital

 TEL: closed reduction + short‑term immobilisation; CEL: closed reduction rarely possible, usually requires osteotomy or ligament reconstruction. Exam questions frequently compare prognosis and when surgical vs. non‑surgical management is appropriate.

Digit Neoplasia (SCC most common)

Breed‑independent but high prevalence; exam may ask the most common digit tumor in dogs (SCC) and the preferred treatment (digit amputation) plus prognosis based on tumour type.

Flexor Carpi Ulnaris (FCU) Tendon Injury

 Large‑breed athletic dogs (Greyhounds, Weimaraners). Unique because MSK ultrasound is the diagnostic modality of choice, and treatment may involve surgical repair vs. conservative rest—often a point‑of‑contrast question.

Puppy Carpal Flexural Contracture Deformity

Hyper‑flexion with “wheel‑barrow test” as a diagnostic clue; recovery time averages 2–3 weeks, and the exam may test the difference in outcome between rest + bandage vs. rest alone for different grades.