Clinical comparison and short-term radiographic evaluation of Tight Rope and Lateral Suture procedures for dogs after cranial cruciate ligament rupture

ABSTRACT: The aim of this study was to monitor short-term osteoarthrosis progress in relation to a recently introduced novel extracapsular method called the Tight Rope procedure and after Lateral Suture with nylon in cruciate-deficient dog stifle joints. Twelve dogs were included in the study. Treatment type was not randomised. Mediolateral radiographs from 12 stifle joint were evaluated preoperatively and six months after surgery. A modified scoring system for evaluation of osteoarthrotic changes was used. The initial osteoarthrotic score in the TightRope group ranged from three to six and in the Lateral Suture group from 0 to 11. In the TightRope group 66.6% of dogs had an osteoathrotic score difference of ≤ 5 and 33.3% dogs had an osteoarthrotic score difference of 5. For the Lateral Suture group 50% of dogs had an osteoarthrotic score difference of ≤ 5 and 50% dogs had an osteoarthrotic score difference of 5. The Wilcoxon signed rank test revealed a significant difference between preoperative and postoperative osteoarthrotic scores (P = 0.0038). No significant differences were noted between TightRope and Lateral Suture groups in terms of changes in mean radiographic osteoarthrotic score preoperatively and at the sixmonth postoperative end point. Both groups had numerically higher radiographic scores six months after surgery. Keywords: cruciate-deficient stifle; extracapsular method; radiology; dog List of abbreviations CCL = cranial cruciate ligament, LS = Lateral Suture, OA = osteoarthrosis, SD = standard deviation, TR = Tight Rope Supported by the Scientific Sponsorship Agency of the Ministry of Education of the Slovak Republic (Project VEGA MS SR No.1/2945/12). Cranial cruciate ligament (CCL) provides craniocaudal stability, prevents hyperextension and constrains medial rotation of the tibia in the canine stifle joint. CCL rupture is the leading cause of hind leg lameness; it is also the most frequent cause of degenerative disease of the canine stifle joint (Johnson and Johnson 1993). The primary goal of surgical management of a CCL rupture is to promote return to normal function, by providing joint stability. Functional stability is thought to minimise or slow down the progression of osteoarthrosis (OA) (Slocum and Slocum 1998). Many surgical procedures have been used to secure the stability of the stifle joint with torn cranial cruciate ligament, but there is no evidence to show that any given surgical treatment is to be preferred the over others (Aragon and Budsberg 2005, Au et al. 2010; Conzemius et al. 2005). These methods can be classified as promoting static or dynamic stabilisation according to the technique used (Boudrieau 2009; Kuhn et al. 2011). Extracapsular Lateral Suture (LS) is a commonly performed technique for static stabilisation of the stifle (Caporn and Roe 1996). More recently, a novel extracapsular method called the Tight Rope procedure (TR) has been introduced, which is based on the lateral retinacular imbrication suture principle (Cook et al. 2010). Our objective was to evaluate outcomes by assessing subjective measurement of cranial drawer and cranial tibial thrust at 6 months after surgery (Cook et al. 2010). Our next objective was to use a previously reported radiographic stifle OA scoring system (Vasseur and Berry 1992) to com- Veterinarni Medicina, 59, 2014 (10): 502–505 Original Paper 503 pare short-term postoperative radiographs, comparing Tight Rope with Lateral Suture techniques. MATERIAL AND METHODS Dogs presented at the Small Animal Clinic, UVM from October 2011 to March 2012 for unilateral hind limb lameness and with CCL rupture as the confirmed cause were considered for study inclusion. Dogs were excluded when concurrent orthopaedic and/or neurological disorders were diagnosed. CCL rupture was diagnosed based on orthopaedic examination of dogs, which consisted of adspection of the dog’s gait and palpation of affected stifle joint, pain, periarticular fibrosis, positive cranial drawer and positive cranial tibial thrust. Treatment type was not randomised. Dogs were pre-medicated, anaesthetised, positioned in dorsal recumbency, and prepared for aseptic surgery. Aseptic technique was strictly adhered to throughout all aspects of both procedures. For all dogs, the CCL was completely debrided. Damaged meniscus, when present, was treated by complete meniscectomy. Tight Rope or Lateral Suture was then performed as previously described (Hulse and Johnson 1997; Cook et al. 2010) to correct stifle instability. A mediolateral radiographic projection of each stifle was evaluated preoperatively and at final examinations. Radiographic evidence of stifle OA was scored using a modification of the system described by Vasseur and Berry (1992). An OA score for each stifle was determined by evaluating 14 specific radiographic features of OA. Structures evaluated included the patella (apical osteophytes, basal osteophytes, cranial apical enthesiopathy), femur (trochlear groove periarticular osteophytes, supratrochlear lysis, fabellar periarticular osteophytes), tibia (cranial periarticular osteophytes, caudal periarticular osteophytes, subchondral cystic lesions, condyle remodelling, central tibial plate