Summary

A seven-year-old, 41 kg, intact, cross breed dog, was presented with a history of bilateral hind limb lameness after falling from a height of 1 m. Clinical and radiographic findings were consistent with bilateral patellar tendon rupture. Surgical repair was performed bilaterally. The tendons were sutured primarily, and an internal splint of nylon leader was added. Good apposition of the severed tendon ends had been achieved intraoperatively; however, post operative radiographs showed supra-trochlear displacement of both patellae. The casts used to immobilize the stifle joints slipped distally and three days post operatively the tendon repair had broken down, bilaterally. Revision surgery was undertaken and the tendons were re-sutured. Nylon leader was placed through holes that had been drilled in the patellae and tibiae. The stifle joints were immobilized with type I external skeletal fixators (ESFs). Both freeform polymethylmethacrylate (PMMA) connecting bars were found to be broken at the level of the stifle joints two days later, without any disruption of the primary tendon repair. Each connecting bar was replaced with two connecting bars of PMMA reinforced with 3 mm steel wire. The dog was fully weight-bearing with a reduced range of motion in flexion immediately after removal of the ESFs at six weeks and was still sound 18 months post-operatively. Primary tendon repair in combination with adequate immobilization allowed for an excellent outcome in a complicated bilateral pathology.