Evaluation of Fibular Head Transposition for Repair of Experimental Cranial Cruciate Ligament Injury in Dogs

Unilateral cranial cruciate ligament excision and fibular head transposition (FHT) were performed on 30 adult dogs. Vertical ground reaction forces were determined using force plate data before and after surgery. Cranial drawer motion, tibial rotation, and varus-valgus motion were measured at monthly intervals. Radiographic, gross, and histological examinations of the stifle joints that had been operated on were performed 3 weeks, 4 months, and 10 months after surgery. A scoring system was used to evaluate lameness, osteophyte formation, and meniscal damage. Rank correlation coefficients were calculated between variables tested in pairs. Cranial drawer motion and abnormal tibial rotation were present in all of the joints that had been operated on. Peak vertical force and associated impulse were not restored during the study time period. Meniscal damage was noted in 25% of the dogs at month 4 and in 50% of the dogs at month 10. Progressive gross and histological deterioration of the articular cartilage was observed in all joints. Positive correlations were noted between the degree of stifle joint instability and meniscal injury or radiographic changes. FHT did not control cranial drawer motion and rotational instability, was not successful in restoring limb function, and did not prevent joint degeneration, especially meniscal damage.     

Cranial cruciate ligament rupture in the dog—a retrospective study comparing surgical techniques

SUMMARY Three surgical techniques, grouped as intra-articular techniques, extra-capsular techniques and fibular head transposition, were used for repair of the cranial cruciate ligament (CCL)-deficient stifle in 113 dogs over a 4 year 4 month period. The clinical outcome of the techniques were compared using information provided by the owners and physical examination. Regardless of surgical technique, 85.7 to 91.0% of dogs showed clinical improvement after surgery. However, less than 50% of dogs became clinically sound on the operated leg and 9.0 to 14.3% of dogs remained persistently lame on the operated leg. No statistical association was found between result after surgery and age, body weight, sex, duration of injury before surgery, association with injury, tibial plateau angle, degree of radiographic osteoarthritis before surgery or the presence of concurrent medial meniscal injury. On physical examination, extra-capsular techniques appeared superior to the fibular head transposition in terms of joint stability and limb function. Concurrent medial meniscal injury necessitating meniscectomy existed in 48.0% of cases. Twenty-two percent of dogs ruptured their contralateral CCL at an average of 14 months after the first.     

Fibular head transposition for repair of cruciate-deficient stifle in the dog

Fibular head transposition (FHT) was introduced as a surgical technique to reconstruct the cruciate-deficient stifle in the dog. Surgically moving the fibular head into a cranial position alters the orientation of the lateral collateral ligament, thereby preventing cranial drawer motion and minimizing internal rotation of the tibia. The technique was found to be safe, mechanically sound, and clinically effective. Comparison of clinical results for this technique with those for the fascial strip technique (using a uniform grading system) demonstrated an overall superior performance of FHT. Factors found to adversely influence clinical results were heavy body weight and meniscal damage. The interval between stifle injury and reconstructive surgery or the presence of associated osteoarthritic disease bore no relationship to clinical outcome. It was concluded that the clinical performance after FHT was equal or superior to other surgical methods for reconstructing the cruciate-deficient stifle in the dog.     

Complications of transposition of the fibular head for stabilization of the cranial cruciate-deficient stifle in dogs: 80 cases (1982-1986)

Over a 5-year period, fibular head transposition was performed in 85 stifles in 80 dogs with rupture of a cranial cruciate ligament. The most common complication during surgery was iatrogenic fracture of the fibular head or neck (10 dogs; 12.5%), and the most common postoperative complication was seroma formation at the lateral aspect of the proximal portion of the tibia overlying the pin (6 dogs; 7.5%). Sixty-nine of 80 owners were contacted for follow-up evaluation of lameness 6 months to 5 years after surgery; 51% reported excellent results, 39% good results, and 10% fair results. Fifty-six dogs were available for long-term follow-up examination; all dogs had some degree of medical thickening of the stifle, 27 (48%) had crepitus, 4 (7%) had signs of pain, and 2 (3.5%) had moderate cranial drawer instability on manipulation of the joint. Results were good or excellent in 90% of the dogs.     

Reduction and stabilization of hip luxation by the transposition of the ligamentum sacrotuberale in dogs: an in vivo study

OBJECTIVES: To evaluate the effectiveness of transposition of the sacrotuberous ligament (LST) for the treatment of coxofemoral luxation in the dog. STUDY DESIGN: In vivo experimental study. SAMPLE POPULATION: Ten mixed-breed dogs (weighing 12 to 26 kg). METHODS: After general anesthesia, the LST was exposed and released from the sacrum with a sacral bone fragment. Coxofemoral luxation was created by capsulotomy and transection of the ligament of the head of the femur. Suture was passed through 2 small holes in the bone fragment to guide transposition of the LST through a tunnel drilled through the acetabulum and femoral head and neck. The suture material was pulled tight and an interference screw was placed into the femoral tunnel to lock the sacral bone fragment and LST securely in the tunnel. Butorphanol was administered for pain relief and dogs were allowed unrestricted activity. Coxofemoral radiographs were obtained at 15-day intervals. Two dogs were euthanatized for macroscopic and histopathologic examinations at 3 months. RESULTS: Release of the sacral bone was moderately difficult. The transposed ligament and bone fragment were of an appropriate length and were easily and securely fixed by a interference screw method. Visible severe lameness, during the first 7 to 10 days improved to mild lameness within 10 to 21 days. Gait was subjectively normal after 5 weeks. No radiographic abnormalities were observed at any time point. Grossly, the LST was intact and apparently viable and functional. On histopathology, the space in the bone tunnel was filled with new tissue and a hyaline-like layer surrounded the LST. The sacral bone fragment attached to the LST was united with the femoral bone. CONCLUSIONS: Transposition of the LST reduced and stabilized experimentally induced coxofemoral luxation in 10 dogs. Survival of the LST up to 3 months and its adaptation to transposition suggest that this surgical technique could be considered as a permanent treatment option for hip luxations. Transposition and fixation of the LST was easy, but releasing the sacral edge of the LST was difficult because of its deep location and division of the origin into 2 branches in some dogs. CLINICAL RELEVANCE: Results of this experimental study suggest that the technique may be satisfactorily used in dogs with coxofemoral luxation.     

Biceps femoris muscle transposition for treatment of cranial cruciate ligament rupture in small breed dogs

The purpose of this study was to evaluate a new extracapsular surgical technique for the treatment of cranial cruciate ligament rupture in small breed dogs. Nine small breed dogs (seven females and two males) weighing ≤ 15 kg were treated with biceps femoris muscle transposition (BFT). The duration of the BFT procedure was 20 min. Each patient underwent a standard clinical protocol and a questionnaire for the owners. Follow-up (at 1, 3, and 12 months postoperative) confirmed significant improvement in all patients, especially at 1 month postoperatively (p < 0.01) and again after complete stifle joint assessment at 3 months postoperatively. After 12 months, only two patients showed a slight increase in osteoarthritis. According to our results, BFT is a simple extracapsular surgical technique that can be used for the treatment of cranial cruciate ligament rupture in small breed dogs.     

Morphometric and Structural Examination of the Collateral Ligaments of the Canine Elbow Joint

The aim of this study was to describe morphological differences between the lateral collateral ligament (LCL) and the medial collateral ligament (MCL) of the canine elbow joint. Forty forelimbs of 22 dogs (adult German shepherd dogs and shepherd mongrels) were dissected. The length and width of defined segments of the ligaments (i. e. total length, areas of origin and insertion, 'free part', 'humeral part', 'antebrachial part') were measured in extension (160°) and flexion (30°). Statistical analyses of the data were performed using the data analysis software SAS 8.0. In addition the collateral ligaments of ten forelimbs of five shepherd mongrels were studied histologically. The LCL differs from the MCL in the following morphological items: a) the areas of origin and insertion are larger and in consequence the 'free part' of the lateral ligament is shorter; b) the caudal crus of the LCL is fan-shaped with a broad insertion area at the ulna whereas the caudal crus of the MCL remains slim; c) in the LCL the 'humeral part' varies in length depending on extended or flexed position of the joint, which is due to the spiral shape of the capitulum humeri; d) the microscopical structure of the LCL is organized less tightly; the collagen fibre bundles cross in varying angles. Referring to these details the LCL seems to allow and to limit a slight rotation of the forearm when the elbow joint is extremely flexed.     

RADIOGRAPHIC AND ULTRASONOGRAPHIC EVALUATION OF THE PATELLAR LIGAMENT FOLLOWING TIBIAL PLATEAU LEVELING OSTEOTOMY

Objective evaluation of patellar ligament changes following tibial plateau leveling osteotomy (TPLO) for cranial cruciate ligament injury has not been published to date. In this study, the patellar ligament was evaluated using radiographs and high-resolution ultrasound in 31 stifles (29 dogs) preoperatively and at 1 month (n=31), 2 months (n=18), and 6 months (n=13) postTPLO. A ratio of the thickness of the proximal to distal patellar ligament was determined for all radiographs evaluated. Ultrasound evaluation included proximal, middle, and distal mid-sagittal thickness and transverse thickness, and transverse area measurements. Subjective grading (0 being normal through a scale of 3) of the ultrasound changes was also performed at each evaluation. Significant thickening of the distal patellar ligament was noted postoperatively as evidenced by thickness and area measurements and a decreased radiographic ratio (P < 0.01). Preoperative patellar ligament thickness and area were similar at the proximal, middle and distal sites. Ultrasound-derived thickness and area measurements of the distal patellar ligament were increased at 1 and 2 months (P < 0.01). The radiographic ratio was significantly decreased at 1, 2 and 6 months (P < 0.01). Subjectively, all patellar ligaments scored a 0 preoperatively and 16/31 received a score of 2 or 3 during follow-up evaluation. Additionally, these dogs had ultrasonographic and radiographic changes consistent with distal patellar ligament thickening. Body weight (kg) and postoperative TPLO angle had a significant influence on 1-month postoperative distal patellar ligament area using a stepwise logistic model (P < 0.05). Patellar ligament desmitis is a common postoperative sequela to the TPLO procedure, however its clinical significance (i.e., correlation with a residual lameness) was not evaluated in this study.     

Risk factors for fibular fracture after TPLO

Objective: To determine (1) risk factors for fibular fracture after tibial plateau leveling osteotomy (TPLO) and (2) if a single postoperative radiographic measurement or measurement ratio of the proximal tibial fragment can be used as a predictor for fibular fracture. Study Design: Multivariate retrospective clinical study. Animals: Dogs (n=326) with cranial cruciate ligament rupture that had TPLO (n=355). Methods: Medical records (January 2004–November 2007) and radiographs of dogs that had TPLO were reviewed. TPLO plate type, distance between tibial plateau and proximal screw, proximodistal tibial plateau fragment length, tibial plateau width, the presence of a fibular drill hole filled with a screw or not, and fibular fractures were recorded. Results: The odds of having a fibular fracture were 10 times greater in dogs with a fibular drill hole than in dogs without a drill hole. The odds of having a fibular fracture were 1.46 times greater for every 4.5 kg increase in body weight. Tibial plateau angle (TPA) at the time of reevaluation was larger than the postoperative TPA and TPA increase was larger in dogs with fibular drill holes than without (P<.01) and in dogs with fibular fractures than without (P<.01). Conclusion: An unfilled fibular drill hole and increased body weight are risk factors for fibular fracture.     

Biomechanical Stability of Four Cranial Cruciate Ligament Repair Techniques in the Dog

Four commonly used cranial cruciate ligament (CCL) repair techniques were compared biomechanically in canine cadaver stifles by assessment of immediate postoperative laxity (cranial drawer) and stiffness. Each joint was tested nondestructively before repair, with the CCL intact and with the CCL excised. The cranio-caudal laxity after each repair was expressed as a percentage of the laxity in the same stifle after CCL excision. The stiffness of a repair was expressed as a percentage of the same intact joint's stiffness at an equivalent displacement. Repaired stifles were tested three consecutive times to the same maximum load (180 N) and the comparative laxity and stiffness in each test were determined. Fibular head transposition resulted in significantly increased stiffness, less laxity, and less decay per test than the other repairs. Lateral imbrication resulted in significantly less laxity on all tests, and significantly greater stiffness than the fascial strip or patellar tendon on the second and third tests to maximum load. The fascial strip resulted in significantly less laxity on all tests than the patellar tendon, but it was not significantly greater in stiffness. These data suggest that, of the reconstructive methods tested, fibular head transposition has biomechanically superior properties in the immediate postoperative period.     

Transposition of the sacrotuberous ligament for the treatment of coxofemoral luxation in dogs

A surgical technique is described for transposition of the sacrotuberous ligament to replace the teres ligament in the treatment of coxofemoral luxation in dogs. Ten dogs with coxofemoral luxation were treated using this technique and all animals regained full limb function within two months of surgery. It is suggested that the technique could be employed in dogs suffering from all types of hip luxations.     

Closed Transventricular Dilation of Discrete Subvalvular Aortic Stenosis in Dogs

Discrete subvalvular aortic stenosis with peak systolic pressure gradients of more than 60 mm Hg was treated by closed transventricular dilation in six young dogs. Peak systolic pressure gradients were measured by direct catheterization before surgery, immediately after dilation, and 3 months after surgery. Maximum instantaneous pressure gradients were measured by continuous wave Doppler echocardiography before surgery and 6 weeks to 9 months after surgery. All dogs survived the procedure, and two dogs were clinically normal after 9 and 14 months. Two dogs died at week 6 and month 7. One dog was receiving medication for pulmonary edema 15 months after surgery. One dog underwent open resection of the subvalvular ring at month 3, and was clinically normal 6 months after the second procedure. Complications included intraoperative ventricular fibrillation in one dog, and mild postoperative aortic insufficiency in one dog. Closed transventricular dilation resulted in an immediate 83% decrease in the peak systolic pressure gradient from a preoperative mean of 97 +/- 22 mm Hg to a mean of 14 +/- 15 mm Hg. However, systolic pressure gradients measured by direct catheterization at month 3 (77 +/- 26 mm Hg), and by Doppler echocardiography at week 6 to month 9 (85 +/- 32 mm Hg) were not significantly different from preoperative values, which suggested recurrence of the aortic stenosis. Closed transventricular dilation should not be considered a definitive treatment for discrete subvalvular aortic stenosis in dogs, but may be useful in young dogs with critical aortic stenosis as a bridge to more definitive surgery.     

Clinical Results Following Nonoperative Management for Rupture of the Cranial Cruciate Ligament in Dogs

Eighty-five dogs were diagnosed as having rupture of the cranial cruciate ligament. They were managed by restriction of activity to leash walks for 3 to 6 weeks, weight loss if indicated, and analgesic medication as needed. Twenty-four of 28 dogs that had a body weight of 15 kg or less (85.7%) were considered to be clinically normal (no lameness and normal range of motion in stifle, 21 dogs) or improved (3 dogs) after an average follow-up period of 36.6 months. Lameness in the remaining four dogs persisted or worsened over an average period of 8.2 months (minimum 6 months), and surgical replacement of the cruciate ligament was performed. Eleven of 57 dogs that had a body weight of 15 kg or greater (19.3%) were classified as normal (4 dogs) or improved (7 dogs) after an average follow-up period of 49.1 months. Lameness in the remaining 46 dogs persisted or worsened over an average period of 10.2 months (minimum 6 months), and surgical replacement of the cruciate ligament was performed.     

Morphometric evaluation of growth in llamas (Lama glama) from birth to maturity.

Normal growth characteristics of llamas (Lama glama) were evaluated from conception until 1 week after parturition in pregnant females (study 1) and from 1 month after birth to maturity (study 2). In study 1, pregnant multiparous llamas (n = 10) were measured at monthly intervals from conception until 1 week after parturition; in study 2, llamas (n = 270) were measured once. Body weight of pregnant llamas (study 1) did not increase significantly until after the eighth month of pregnancy. Llamas of study 2 reached mature height, length, thoracic circumference, and weight at 18, 24, 36, and 36 months of age, respectively. From 1 month of age to maturity, the growth characteristics of males, nonpregnant females, and females during the first 8 months of pregnancy did not differ. Correlations (r2) between height, length, and thoracic circumference related to body weight for all but the pregnant llamas during the last 3 months of pregnancy were 0.822, 0.834, and 0.948, respectively. The equation describing thoracic circumference as a predictor of body weight was: Weight (kg) = (1.005 x 10(-3)) x circumference (cm)2.424.     

Popliteal Tendon Transposition for Stabilization of the Cranial Cruciate Ligament Deficient Stifle Joint in Dogs: An Experimental Study

Popliteal tendon transposition was performed in five dogs with surgically induced cranial cruciate ligament rupture. After a lateral approach to the stifle joint, the popliteal tendon was severed distal to the sesamoid bone and transposed cranially onto the tibial crest to mimic the sagittal orientation of the cranial cruciate ligament. The origin of the popliteal tendon on the lateral femoral condyle was preserved. Lameness was not clinically detectable 2 months after surgery. At 6 months postoperatively, there was minimal radiographic and histopathologic evidence of degenerative joint disease in the stifle joints that had underwent surgery. There was no gross or microscopic evidence of meniscal damage found at necropsy 6 months after surgery. Biome-chanical studies are warranted before recommending the procedure.     

Morphology and correction of distal tibial valgus deformities

OBJECTIVES: To characterise distal tibial valgus deformities in dogs through physical examination and radiographic evaluation. Methods: In a clinical study of 16 client-owned dogs, twelve unilateral and four bilateral distal tibial valgus deformities were evaluated using palpation and radiographs. The origin and amplitude of angulation, rotation and length deficits if present were measured. Radiographically, fibular length and position in relation to the tibia was compared in affected and clinically normal limbs. The dimensions of the fibular physes were also compared between clinically normal and affected limbs. RESULTS: Rottweilers and Shetland sheepdogs were overrepresented. Valgus deformities ranged from 16 degrees to 48 degrees (median, 32 degrees ) in affected and from 0 degrees to 13 degrees (median, 6 degrees ) in contralateral, clinically normal limbs. Fibular length, fibular position relative to the tibia or physeal dimensions were not statistically different between affected and clinically normal limbs. CONCLUSION AND CLINICAL RELEVANCE: Many distal tibial valgus deformities in dogs are a uniplanar deformity without concurrent craniocaudal or rotational changes or length deficits. A growth cessation in the fibula does not appear to be responsible for the development of the deformity.     

The Effect of Intercondylar Notchplasty on the Normal Canine Stifle

This study evaluated the effect of notchplasty (enlargement of the intercondylar fossa) in stable and unstable canine stifles. Bilateral notchplasty and unilateral cranial cruciate ligament (CrCL) transection were performed in 6 dogs. Exercise, consisting of walking 1.5 miles three times a week, began 1 month after surgery and continued until euthanasia 6 months after surgery. Evaluation methods included orthopedic examination, serial radiographs, thin section radiography, histopathology, and gross pathology. Notchplasty in the stable stifle did not cause lameness beyond 3 weeks, joint instability, or degenerative joint disease. In the stable stifle, smooth resurfacing of the notchplasty site with fibrous and osseous tissue occurred. Stifles with notchplasty and CrCL transection exhibited persistent lameness, instability, and degenerative joint disease. In CrCL deficient stifles osteophytes formed within the notchplasty site, resulting in a rough surface. Our observations indicated significant refilling in notchplasties of both stable and unstable stifles ( P <.05). However, the intercondylar fossa (ICF) width 6 months after notchplasty was significantly smaller in unstable stifles compared with stable stifles ( P <.05) indicating that greater refilling of the notchplasties occurred in the unstable stifles. In clinical cases, notchplasty should be larger than the desired final result to accomodate the partial refilling that occurs even in stable stifles.     

Evaluation of Internal Obturator Muscle Transposition in Treatment of Perineal Hernia in Dogs

A technique that utilizes transposition of the internal obturator muscle for repair of perineal hernias was evaluated. Forty-two male dogs were followed for at least one year after surgery. The repair failed in only one animal, a dog with previously operated bilateral hernias. Microangiography demonstrated an adequate blood supply to the transposed internal obturator muscles of two dogs examined at three weeks and three months after surgery.     

Prevalence of Urinary Tract Infection in Dogs after Surgery for Thoracolumbar Intervertebral Disc Extrusion

Background: Urinary tract infection (UTI) is a common complication in people with spinal cord injury (SCI). Dogs with acute intervertebral disc extrusion (IVDE) have similar risk factors for UTI when compared with human SCI patients and have a high perioperative prevalence of UTI. Objectives: Determine the prevalence of UTI in dogs for 3 months after surgery for thoracolumbar IVDE and identify risk factors for development of UTI. Animals: Twenty‐five dogs treated surgically for 26 acute disc extrusions. Methods: Prospective study. Urinalysis and urine culture were performed perioperatively. At home, owners monitored urine with dipsticks every 48 hours for 1 month then once a week until 3 months. Dogs returned for assessment of motor function, urinalysis, and urine culture at 1 and 3 months after surgery. Presence of UTI over the 3‐month period was correlated to potential risk factors. Results: Ten dogs (38%) developed 12 UTIs over the 3‐month period, with the majority occurring between weeks 1 and 6; 60% of the UTIs were occult. Hematuria in the absence of pyuria or UTI was a common finding in the perioperative period. Sex, breed, and ambulatory status influenced the risk of developing a UTI. Conclusions and Clinical Importance: There is a high prevalence of UTIs, many of which are occult, in the 3 months after surgery for thoracolumbar IVDE. These dogs should be routinely monitored for UTI with urine culture regardless of urinalysis results.