Evaluation of the Marsh Deer Stifle Joint by Imaging Studies and Gross Anatomy

This study aimed to evaluate the stifle joint of marsh deer using imaging studies and in comparison with gross anatomy. Ten hindlimbs from 5 marsh deer (Blastocerus dichotomus) were used. Radiography, computed tomography (CT) and magnetic resonance imaging (MRI) were performed in each stifle joint. Two hindlimbs were dissected to describe stifle gross anatomy. The other limbs were sectioned in sagittal, dorsal or transverse planes. In the craniocaudal radiographic view, the lateral femoral condyle was broader than the medial femoral condyle. The femoral trochlea was asymmetrical. Subsequent multiplanar reconstruction revealed in the cranial view that the external surface of the patella was roughened, the medial trochlea ridge was larger than the lateral one, and the extensor fossa at the lateral condyle was next to the lateral ridge. The popliteal fossa was better visualized via the lateral view. Sagittal MRI images identified lateral and medial menisci, caudolateral and craniomedial bundles of cranial cruciate ligament, caudal cruciate ligament, patellar ligament and common extensor tendon. In conclusion, the marsh deer stifle presents some anatomical characteristics of the ovine stifle joint.     

Synovial T-cell lymphoma of the stifle in a dog

A 6-year-old, 43-kg, spayed female rottweiler was presented for a 1-month history of progressive, left hind-limb lameness. Upon physical examination, a cranial drawer sign and joint distention were present in the left stifle. Radiographically, the stifle had evidence of effusion, remodeling of the patella, and an enlarged popliteal lymph node. Marked synovial thickening and an intact cranial cruciate ligament were noted during surgery. Despite finding a nonspecific, mixed inflammatory response on joint fluid cytopathology, histopathology demonstrated T-cell lymphoma of the synovium. Lameness may be the sole presenting clinical sign in canine lymphoma.     

Experimental cranial cruciate replacement in cattle using a patellar ligament graft

The cranial cruciate ligament was surgically removed from the right stifle joint in ten heavy steers and two bulls, and replaced with a tendon-ligament graft harvested from the tendon of the gluteobiceps muscle including a portion of the lateral patellar ligament. Two surgical techniques (placing the graft through a femoral bone tunnel and placing the graft through the joint space) were compared using six animals in each group.

Both surgical techniques were easily performed and caused minimal postoperative inflammation. The clinical response observed over four to five months was considered satisfactory in 9 of 12 animals. However, the tensile strength of the graft determined at necropsy was less than the cranial cruciate ligament in the opposite normal stifle in all animals tested.

     

Clinical Results of Surgical Correction of Medial Luxation of the Patella in Dogs

Thirty-four dogs that had surgical correction of medial patellar luxation (MPL) in 52 stifle joints were examined after a minimum follow-up period of 1 year (median, 3.6 years). The dogs were divided into the following three groups depending on their age at the time of surgery: group 1, 3 to 6 months; group 2, 8 to 20 months; and group 3, 2.2 to 12 years. Two of the dogs in group 3 had ruptured their cranial cruciate ligament in addition to having MPL. The results were based on a clinical assessment of the animal's gait, and physical and radiographic examination of the stifle joints. Six of seven stifle joints evaluated in group 1 had radiographic evidence of moderate to severe degenerative joint disease of the patellofemoral joint, and in two of the joints recurrence of MPL was observed. Failure to maintain reduction of the patellofemoral joint was also observed in 11 of 22 (50%) and 12 of 23 (52%) of the stifle joints in groups 2 and 3, respectively. In the latter groups, mild degenerative joint disease was evident radiographically in stifle joint that had not maintained reduction. Four of the 34 dogs were consistently (n = 2) or intermittently (n = 2) lame; the two dogs that were consistently lame had cranial instability of the stifle consistent with rupture of the cranial cruciate ligament. In the latter two dogs, the cranial cruciate ligament had been intact at the time of surgery for correction of MPL.     

ULTRASONOGRAPHIC ANATOMY OF THE NORMAL CANINE STIFLE

Ultrasonographic examination of the normal canine stifle joint was performed to characterize its normal anatomy. Stifles of four normal adult dogs were imaged in sagittal and transverse planes and each anatomic structure visualized was recorded. Normal anatomic structures consistently seen included the patellar tendon, medial and lateral menisci, the cranial cruciate ligament and femoral condyle cartilage. The caudal cruciate ligament was visualized in two dogs. Collateral ligaments and meniscal ligaments were not visualized. The dogs were then euthanized and each stifle was isolated. Following removal of superficial muscles and skin, each stifle was imaged in a water bath to definitively identify the structures that had previously been visualized on the live dogs. The ultrasonographic appearance of the isolated stifle specimens was similar to that found in live dogs. The results of this study indicate that ultrasound can be used to image the normal anatomy of the canine stifle. The echogenicity of the patellar ligament, cruciate ligaments, menisci and articular cartilage was similar to that previously reported in equine stifles and human knees.     

Preliminary study evaluating tests used to diagnose canine cranial cruciate ligament failure

O bjective : To estimate specificity, sensitivity, positive predictive value and negative predictive value of tests and signs used for the diagnosis of cranial cruciate ligament failure in dogs.
M ethods : One stifle in each of 42 dogs was examined: 25 "affected" and 17 "control" dogs. All dogs were subjected to the following tests when conscious: cranial drawer, tibial compression, patellar tendon palpation and palpation of the medial aspect of the joint. Under general anaesthesia, cranial drawer and tibial compression tests were repeated and a lateral stifle radiograph was taken to evaluate changes of the infrapatellar fat pad. The results were analysed using a 2×2 table method. Sensitivity, specificity, positive predictive value and negative predictive value were estimated.
R esults : The sensitivity of the cranial drawer and tibial compression tests was surprisingly low when performed on conscious patients but significantly better when performed under anaesthesia. Similarly, palpation of the medial aspect of the stifle joint cannot be considered a reliable indicator of cranial cruciate ligament injury. Patellar palpation and radiographic assessment showed excellent sensitivity, specificity, positive predictive value and negative predictive value.
C linical S ignificance : In the diagnosis of cranial cruciate ligament, it is essential that the clinician is aware of each test's features and limitations to reduce the risk of misdiagnosis.     

Cranial cruciate stability in the rottweiler and racing greyhound: an in vitro study

An in vitro biomechanical study of cadaver stifles from rottweilers and racing greyhounds was undertaken to evaluate the contribution of the cranial cruciate ligament to stifle joint stability. This was performed at differing stifle joint angles, first with the joint capsules and ligaments intact and then with all structures removed except for the cranial cruciate ligament. Craniocaudal laxity increased in both breeds as stifle flexion increased. The rottweiler stifle showed greater craniocaudal joint laxity than the racing greyhound at all joint angles between 150 degrees and 110 degrees, but the actual increases in joint laxity between these joint angles were similar for both breeds. Tibial rotation during craniocaudal loading of the stifle increased craniocaudal laxity in both breeds during joint flexion. The relative contribution of the cranial cruciate ligament to cranial stability of the stifle joint increased as the joint flexed and was similar in both breeds.     

Radiographic measurement of craniocaudal instability in stifle joints of clinically normal dogs and dogs with injury of a cranial cruciate ligament

OBJECTIVE: To determine craniocaudal laxity of the stifle joint of dogs when joints were positioned in tibial compression or neutral position. SAMPLE POPULATION: 19 normal stifle joints in 10 clinically normal dogs, 29 stifle joints with varying injury to the cranial cruciate ligament (10 complete ruptures alone, 10 complete ruptures with concomitant damage to the medial meniscus, 6 partial ruptures alone, and 3 partial ruptures with concomitant meniscal tearing), and 19 unaffected contralateral stifle joints in those 29 dogs. PROCEDURE: Relative displacement of bony landmarks was measured on paired lateral radiographs (neutral and tibial compression positions). Two measuring techniques were customized for use in dogs. RESULTS: The first technique failed to distinguish results in normal stifle joints from those in stifle joints with partial deficiency of cranial cruciate ligaments. Significant differences were found for joints with complete rupture, compared with stifle joints in clinically normal dogs. The second technique detected differences between normal stifle joints and injured joints with partial or complete rupture of the cranial cruciate ligament. Significant differences were not detected between joints with partial versus complete rupture. Adjusting data to account for size of dog did not improve results. CONCLUSIONS AND CLINICAL RELEVANCE: A wide range in measurements of laxity was found for stifle joints with intact cranial cruciate ligaments. Differences in degree of damage to the ligament and medial meniscus cannot be deduced from the amount of relative displacement measured on radiographs. Pathologic changes to the cranial cruciate ligament will not necessarily induce detectable changes in laxity of stifle joints in dogs.     

Radiographic assessment of the progression of osteoarthrosis in the contralateral stifle joint of dogs with a ruptured cranial cruciate ligament

The formation and progression of osteoarthrosis in the unaffected contralateral stifle joints of 14 dogs with a unilateral cranial cruciate ligament rupture were monitored radiographically in terms of a global score and the scores for 10 parameters specific for the stifle joint. The dogs were examined initially and six and 12 months later by three observers, and the variability between the observers' scores was also assessed. The score for osteophytes at the tibial attachment site of the ligament was the most reliable parameter, and that for the increase in femoropatellar joint space was the least reliable. In the contralateral stifle joints there were significant increases after six and 12 months in osteophyte formation caudal to the tibial plateau, and in subchondral sclerosis of the tibial plateau and of the long digital extensor muscle groove. These three parameters progressed more regularly during the disease process than the other parameters. The global osteoarthrosis score of the contralateral stifle joint was an important risk factor for sustaining a rupture of the cranial cruciate ligament in that joint during the next six months.     

ECHOGRAPHIC EXAMINATION OF THE STIFLE JOINT AFFECTED BY CRANIAL CRUCIATE LIGAMENT RUPTURE IN THE DOG

Ultrasound is a useful technique for the study of normal and pathologic stifle joints, in particular for soft tissue examination. The aim of this study was to evaluate sonography for examination of stifle joints affected by cranial cruciate ligament rupture. Forty-two medium to giant breed dogs were studied. Tibial compression radiography was performed. A 7.5 MHz transducer with an incorporated 2 cm thick standoff was employed. Sagittal and midsagittal images were collected. The stifle was positioned in maximum flexion during sonography. Sonographic findings were compared with pathologic findings at surgery. Ultrasound was useful in evaluating the presence of fibrous tissue within the joint due to repair processes. It was observed in 70% of stifles with radiographic evidence of chronic osteoarthritis. In 19.6% of the joints it was possible to identify the ruptured cranial cruciate ligament. Ultrasound was not an accurate test for cruciate rupture evaluation, but was specific for the soft tissue pathologic changes which were observed consequent to joint instability.     

Multiple ligamentous injuries of the canine stifle joint: a study of 12 cases

Multiple ligamentous injuries of the canine stifle are uncommon. In this study, they affected mainly adult, male, working or sporting dogs and occurred secondary to severe trauma, or where chronic joint infection had weakened the supporting structures. Rupture of the cranial cruciate, caudal cruciate and lateral collateral ligaments was the most common injury observed and this occurred after catching the limb in a fence or gate. Reconstruction of the collateral and cranial cruciate ligaments, and careful repair of damaged menisci and joint capsule, was an effective method of treatment for medium- and large-size dogs. Reconstruction of the caudal cruciate ligament and postoperative limb support was not found to be essential. All dogs with subluxated stifles had good to excellent limb function with minimal loss of mid-thigh circumference or stifle joint range of motion at follow-up. Less favourable results were achieved where there was stifle joint luxation with extensive disruption to secondary joint restraints.     

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.     

Evaluation of the Lateral Collateral Ligament After Fibular Head Transposition in Dogs

Cranial transposition of the fibular head stabilizes the stifle joint by displacing the distal attachment of the lateral collateral ligament (LCL). The forces applied to the LCL after displacement may cause ligamentous elongation. This investigation evaluated the morphological, histological, and biomechanical changes of the LCL after fibular head transposition (FHT) in dogs. Unilateral cranial cruciate ligament (CCL) excision and FHT were performed on 25 dogs. Cross-sectional area, length, histological, and structural properties of the LCL were evaluated 3 weeks, 4 months, and 10 months after surgery. Ligament length means were significantly increased at week 3, month 4, and month 10 compared with intraoperative length means. No significant changes in elongation were observed after week 3. Fibrovascular proliferation within the LCL increased the cross-sectional area and associated structural properties.     

Partial rupture of the cranial cruciate ligament of the stifle in dogs: 25 cases (1982-1988)

Partial rupture of the cranial cruciate ligament was diagnosed in 25 dogs. In all dogs, the primary problem at the time of physical examination was hind limb lameness. The mean time from initial onset of lameness to diagnosis at exploratory surgery was 17 weeks. A cranial drawer sign was detected in 13 of the 25 dogs; in 9, the cranial drawer sign was evident only when the stifle was positioned in flexion. Of the 25 dogs, 12 had no detectable cranial drawer sign in response to manipulation of the involved stifle. In all dogs, lateral stifle arthrotomy was performed in routine manner, and the cranial cruciate ligament was found to be incompletely torn. Lesions identified during arthrotomy were rupture of the craniomedial band (n = 20 dogs), interstitial tear (n = 4 dogs), and rupture of the caudolateral band (n = 1 dog).     

Cranial tibial thrust: a primary force in the canine stifle

A cranially directed force identified within the canine stifle joint was termed cranial tibial thrust. It was generated during weight bearing by tibial compression, of which the tarsal tendon of the biceps femoris is a major contributor, and by the slope of the tibial plateau, found to have a mean cranially directed inclination of 22.6 degrees. This force may be an important factor in cranial cruciate ligament rupture and in generation of cranial drawer sign.     

Cranial cruciate ligament injury in the dog: pathophysiology, diagnosis and treatment

Cranial cruciate ligament (CCL) disease in the dog is a multifactorial complex problem that requires a thorough understanding of the biomechanics of the stifle joint to be understood. Successful treatment of rupture of the CCL should be based on managing underlying anatomical and conformational abnormalities rather than attempting to eliminate the tibial cranial drawer sign. The cranial and caudal cruciate ligaments, the patella ligament and quadriceps mechanism, the medial and lateral collateral ligaments, the medial and lateral menisci and the joint capsule provide stability of the joint and load-sharing. The function of the stifle is also significantly influenced by the musculature of the pelvic limb. An active model of biomechanics of the stifle has been described that incorporates not only the ligamentous structures of the stifle but also the forces created by weight-bearing and the musculature of the pelvic limb. This model recognises a force called cranial tibial thrust, which occurs during weight-bearing, and causes compression of the femoral condyles against the tibial plateau. In middle-aged, large-breed dogs, forces acting on the CCL together with conformation-related mild hyperextension of the stifle and slightly increased tibial plateau slopes are suspected to cause progressive degeneration of the ligament. Palpation of craniolateral stifle laxity has become pathognomonic for CCL rupture; however, chronic periarticular fibrosis, a partial CCL rupture, and a tense patient, may make evaluation of instability of the stifle difficult. Surgical treatment is broadly separated into three groups: intracapsular, extracapsular, and tibial osteotomy techniques. Tibial osteotomy techniques do not serve to provide stability of the stifle but rather alter the geometry of the joint to eliminate cranial tibial thrust such that functional joint stability is achieved during weight-bearing. Visualisation of both menisci is a critical aspect of CCL surgery, irrespective of the technique being performed. Regardless of the surgical technique employed, approximately 85% of dogs show clinical improvement. However, many of these dogs will demonstrate intermittent pain or lameness. Post-operative management is an integral part of the treatment of CCL rupture, and significant benefits in limb function occur when formalised post-operative physiotherapy is performed.     

Evaluation of Experimental Transection and Partial Excision of the Caudal Cruciate Ligament in Dogs

The caudal cruciate ligament (CaCL) of one stifle joint in seven dogs was transected and a 2 to 4 mm section was removed. Six months after surgery, none of the dogs were lame. Thigh muscle circumference, stifle range of motion, and internal tibial rotation in the operated limb were not significantly different from the preoperative measurements or the contralateral, unoperated limb. A caudal drawer motion was consistently present in the stifle joints with a transected CaCL. A radiographic evaluation of the operated stifle joints did not reveal osteoarthritic changes; four of seven stifle joints had an irregular fat pad 6 months after surgery. Results of a joint fluid analysis revealed a slight increase in synovial cells within treated stifle joints; inflammatory cells were not observed. The only gross morphologic change in stifle joints with a severed ligament was enlarged knobby remnants of the CaCL. Articular cartilage defects or osteophytes were not observed. Results of a histologic examination of the CaCL remnants revealed synovial cellular capping and intraligamentous fibroplasia. Based on a limited number of dogs, it was concluded that isolated transection of the CaCL produced minimal clinical and pathologic changes in the stifle joint during a 6 month period.     

Factors affecting width of the canine femorotibial joint space in nonweight-bearing radiographs.

Caudocranial stifle radiographs with variations in positioning were made in two greyhound cadavers. Radiographs were repeated after each of three interventions: cranial cruciate desmotomy; release of the caudal horn of the medial meniscus; complete medial meniscectomy. The joint space on medial and lateral aspects of the joint was measured by a observer who was unaware of positioning or intervention. One dog had significantly wider joint space than the other (1.0 vs. 1.5mm). The lateral aspect of the joint space was wider than the medial aspect (1.7 vs. 0.7 mm). Medial rotation of the stifle resulted in an increase of 0.4 mm in width of the lateral joint space, whereas lateral rotation of the stifle reduced the lateral joint space by an average of 0.4 mm. Decentering the X-ray beam had no significant effect on joint space width. Tension increased the width of the medial joint space by an average of 1.2 mm and the lateral aspect by an average of 1.3 mm. Cranial cruciate desmotomy resulted in an average 0.3 mm increase in width of the joint space, and medial meniscectomy with an average 0.2 mm reduction of the joint space. Although the femorotibial joint space was affected by iatrogenic stifle injuries and by medial or lateral rotation, these changes were less than the differences between the two dogs. Hence it seems unlikely that the small changes in joint space width associated with cruciate ligament desmotomy and medial meniscectomy will be detectable in clinical practice.