Risk factors and long-term surgical outcome of patellar luxation and concomitant cranial cruciate ligament rupture in small breed dogs

Concomitant cranial cruciate ligament rupture (CCLR) is a common complication in small breed dogs with patellar luxation (PL) with an elusive pathogenesis. Surgical treatment is available and commonly includes remodelling osteotomies. While these modern techniques have shown good functional results, access is limited due to the high costs for owners and the need for special surgical equipment. The objectives of the study were to evaluate the frequency and risk factors for concomitant CCLR in small breed dogs with PL. To study the outcome and complications of the combination of the Wedge recession osteotomy (WR) and Tibial tuberosity transposition (TT) with a Fascia over-the-top (OT) or a Capsular and fascial imbrication technique (CFI) for the simultaneous treatment of PL and concomitant CCLR. A retrospective study is presented here. The signalment, body weight, luxation grade and direction, affected side, bilateral or unilateral PL, CCLR and meniscal status were analysed. The surgical treatment for PL and concomitant CCLR, outcome and complications were investigated. Of 233 small breed dogs with PL, 52 (22.31%) had a concomitant CCLR. Maltese dogs were more likely to have concomitant CCLR. The mean age for the dogs with PL only was 5.32 years, which was significantly younger than the mean age of dogs with PL and concomitant CCLR (7.39 years). Overweight dogs with PL were prone to develop concomitant CCLR. Surgical stabilisation with a combination of WR, TT and OT or CFI had excellent or good results in 86.63% of the cases, while 16.67% of the cases developed complications. In conclusion, PL and concomitant CCL ruptures can be managed successfully by performing a combination of WR, TT and OT or CFI. The outcomes and complication rates are comparable to remodelling osteotomies. Moreover, these techniques are less expensive and can be performed with standard surgical equipment. These findings should be beneficial for clinical diagnosis, client education and treatment.