Surgical repair of congenital lateral luxation of the patella in an Arabian foal using a polypropylene mesh

A 3-h-old, 40-kg Arabian filly was referred to the Veterinary Teaching Hospital, due to inability to stand and nurse after birth. The left stifle was oedematous and warm, and the patella was palpated lateral to the distal end of the femur. Radiographs of the left stifle confirmed the patella to be positioned laterally. The trochlear groove of the femur appeared of normal depth, and no other radiographic abnormalities were observed. The filly was leucopenic (white blood cell count 3.0 x 109/L; reference range 6.9–17.0 x 109/L) and had a normal packed cell volume [40% (RR 37–50%)] and low concentration of total serum protein [44 g/L (RR 51–78 g/L)] suggesting the filly likely suffered from failure of passive transfer. The filly was surgically treated for lateral patellar luxation by transecting the lateral parapatellar fascia, imbricating the medial parapatellar fascia and suturing a polypropylene mesh to the imbricated fascia. Post-operative complications included dehiscence of the lateral incision, a subcutaneous abscess on the medial aspect of the stifle and synovial sepsis of the femoropatellar joint. The filly was sound at the walk 10 months after surgery, and no osseous abnormalities were noted on examination of radiographs of the left stifle at that time.