ly be provoked by the specific anatomy of the ovine patellofemoral joint (small lateral femoral condyle, patella located outside and proximal to the trochlear groove in extension, proximolateral to distomedial angle of the trochlear groove \[[@B17]\]), together with the high loading forces resulting from an unprotected rise from the lying down position \[[@B49]\]. Besides, the high luxation rate following the classical approach may possibly be ascribed in part to a genetic predisposition for patellar luxation in sheep \[[@B50]\]. Altogether, these factors may favour a unilateral experimental set-up, allowing for at least one pain-free hindleg to facilitate postoperative rising and standing.

Clinical signs of patellar luxation include persistent, abnormal hindleg carriage with the stifle joint flexed, lameness, and -especially in bilateral luxations- crouching, bowlegged or knock-kneed stance (Table [1](#T1){ref-type="table"}), and may usually be perceived upon postoperative weightbearing (circa 24 hours after surgery). The suspected diagnosis can be affirmed by clinical examination: When luxated, the patella is palpable laterally, with a grinding sensation when being mobilized and a snapping sound upon reduction. Although not necessary routinely, additional radiological examination by X-ray (anteroposterior (Figure [3](#F3){ref-type="fig"}) or flexed dorsoproximal-dorsodistal radiographic views \[[@B50]\]) may confirm the diagnosis. In this report, the initial treatment of these grade II-III luxations was non-operatively, but as lameness and non-weightbearing worsened, soft tissue revision surgery (capsular and retinacular imbrication) was performed. In order to preserve the femoral trochlea, osseous reconstruction procedures initially developed for the canine model \[[@B50]\] such as trochleoplasty \[[@B51]\] or tibial tuberosity transposition \[[@B52]\] were avoided here. Intriguingly, the postoperative rate of re-luxations was of 80%. In good agreement, failure rates of 80% and 50% have been reported for the 