Long digital extensor tendon avulsion in the dog
7-month-old Great Dane with a 3-week right hind limb lameness after rough play. There is stifle effusion and pain on craniolateral palpation; there is no cranial drawer and the patella is stable. Radiographs show a small bone fragment craniodistal to the lateral femoral condyle, with a defect at the extensor fossa.
What is the most appropriate treatment?
chevron_right Show answer and explanation
A. TPLO, because the lameness is due to cranial stifle instability
There is no cranial drawer: the stifle is stable craniocaudally. The problem is avulsion of the tendon origin, which is not corrected by a tibial osteotomy.
B. Curettage of the bed as for osteochondritis of the lateral femoral condyle
Stifle OCD affects the articular surface of the condyle, not the extensor fossa. Here there is an avulsed fragment carrying the tendon origin, which should be reattached.
C. Reattachment of the fragment to its origin (screw or spiked washer); if chronic, tenodesis of the tendon to the proximal tibia
Correct. The long digital extensor originates from the extensor fossa of the lateral femoral condyle; in young large-breed dogs it can avulse with a bone fragment. Reattaching it or fixing the tendon to the tibia restores function with a good prognosis.
D. It needs no surgery: the fragment always resorbs with NSAIDs and rest
An intra-articular avulsed fragment does not resorb reliably; it can perpetuate synovitis and lameness and promote osteoarthritis.
lightbulb Key takeaway
In a young large-breed dog with a stable lame stifle, effusion and craniolateral pain, look for a fragment next to the lateral femoral condyle. It is an uncommon injury but has a good prognosis if recognised.
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Updated: October 31, 2026 · Educational content for veterinary professionals. It does not replace current clinical guidelines or the judgement of the attending veterinarian.