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.     

Rupture of the cranial cruciate ligament associated with deformity of the proximal tibia in five dogs

Excessive mechanical stress due to caudal sloping of the tibial plateau may result in early breakdown of the cranial cruciate ligament (CrCL). Five dogs with CrCL rupture associated with caudal sloping of the proximal tibial plateau are described. All were small dogs, of between three and six years of age, with a mean bodyweight of 9.3 kg, which had acute hindlimb lameness. Radiographic examination revealed cranial displacement of the tibia, with a tibial angle varying from 58 to 60 degrees. All cases were treated with a lateral fabellotibial suture and cranial cuneiform osteotomy of the proximal tibia. All dogs were using the operated limb three days after surgery, with normal gait re-established after a mean period of 10 days. Excessive tibial plateau sloping is not a frequent cause of hindlimb lameness in small animals, although it is important to consider it as a predisposing factor for rupture of the CrCL.     

MORPHOMETRIC ASSESSMENT OF THE PROXIMAL PORTION OF THE TIBIA IN DOGS WITH AND WITHOUT CRANIAL CRUCIATE LIGAMENT RUPTURE

Based on the clinical observation that dogs with a steep tibial plateau slope had variable tibial morphology, we hypothesized that these dogs could be further characterized using measurements developed by examining computer generated models of specific proximal tibial malformations. A 3D tibial model was created from a normal canine tibia. The model was manipulated to reproduce two specific proximal tibial anomalies representing deformities originating from the tibial plateau or the proximal tibial shaft. Data from these models were used to create specific measurements that would characterize the shape of these anomalies. These measurements included the diaphyseal tibial axis (DTA)/proximal tibial axis (PTA) angle, which defined the orientation of the proximal portion of the shaft in relation to the tibial mid-shaft. These measurements were then made on radiographs of dogs with and without cranial cruciate ligament (CCL) rupture. Models with tibial plateau and proximal shaft deformities had a steep tibial plateau slope (TPS). Models with proximal shaft deformity had a markedly increased DTA/PTA angle. The model with a 10 degree proximal shaft deformity had a DTA/PTA angle of 11.23 degrees. Six dogs (9.0%) had a DTA/PTA angle larger than 11.23 degrees (range, 11.4-13.9 degrees). Dogs in this group had ruptured CCL and a steep TPS. Dogs with CCL rupture had higher TPS (mean, 31.8 +/- 4.1 degrees) and DTA/PTA angle (mean, 6.0 +/- 3.3 degrees) than dogs without CCL rupture (means, 23.6 +/- 3.4 degrees and 4.1 +/- 2.2 degrees, respectively). Dogs with proximal shaft deformity represented a distinct group, which could not be identified using the magnitude of the TPS alone. Characterizing more precisely the shape of the proximal portion of the tibia in dogs contributes to our understanding of the pathogenesis of steep TPS and may facilitate the optimization of the surgical management of dogs with CCL rupture.     

Risk Factors Associated with Fibular Fracture After Tibial Plateau Leveling Osteotomy

Objective— To determine the incidence of, and risk factors for, fibular fracture after tibial plateau leveling osteotomy (TPLO) in dogs.
Study Design— Case series.
Sample Population— TPLO (n=168) on 142 dogs.
Methods— Medical records (January 2006–September 2007) and radiographs of all dogs that had TPLO were reviewed. Data retrieved were breed, sex, age, weight, type of plate, use of a jig, time to recheck, preoperative tibial plateau angle (TPA), immediate postoperative TPA, and presence or absence of fibular fracture.
Results— Fibular fractures occurred in 5.4% TPLOs. Body weight, change in TPA, and preoperative TPA were significantly higher in dogs with fibular fracture. TPLO without use of a jig was significantly associated with fibular fracture. Age, postoperative TPA, and plate type were not significantly associated with fibular fracture.
Conclusions— Fibular fracture is uncommon after TPLO. Risk factors are increased body weight, greater preoperative TPA, greater change in TPA, and TPLO performed without a jig. All fractures occurred during convalescence.
Clinical Relevance— Owners should be warned of potential complications and risk factors associated for fibular fracture after TPLO.     

Tibial tuberosity avulsion fracture in dogs: a review of 59 dogs

OBJECTIVES: To evaluate the high incidence of tibial tuberosity avulsion fracture diagnosed in skeletally immature Staffordshire bull terriers presenting to a UK animal welfare charity hospital. METHODS: A retrospective review of tibial tuberosity avulsion fractures treated by the hospital between 2002 and 2007. RESULTS: Sixty-five tibial tuberosity avulsion fractures were recorded in 59 dogs. Fifty-one tibial tuberosity avulsion fracture-affected dogs (86 per cent) were Staffordshire bull terriers. Dogs sustaining tibial tuberosity avulsion fractures had median and mean ages of five and 4.9 months, respectively (range three to 10 months). Where recorded, injury was associated with a short fall or jump (typically 3 to 4 feet) in 29 of 50 dogs. Three fracture patterns were recorded: 37 stifles sustained isolated tibial tuberosity avulsion fracture; 15 stifles sustained tibial tuberosity avulsion fracture accompanied by separation of the proximal tibial epiphysis; in 13 stifles epiphyseal separation extended to produce Salter-Harris type II fracture of the caudal tibial metaphysis. On analysis of the hospital database, tibial tuberosity avulsion fracture was a reason for presentation in 51 (3.3 per cent) of 1536 Staffordshire bull terriers, but only five (0.18 per cent) of 2815 other breed dogs, registered under the age of 12 months during the study period (P<0.001). CLINICAL SIGNIFICANCE: Staffordshire bull terriers commonly present with tibial tuberosity avulsion fracture, with or without concurrent separation of the proximal tibial epiphysis, to this urban charity hospital.     

In vitro effects of osteotomy angle and osteotomy reduction on tibial angulation and rotation during the tibial plateau-leveling osteotomy procedure

OBJECTIVE: To determine the effect of osteotomy angle, reduction technique, and tibial plateau rotation angle on angular and rotational limb deformities. STUDY DESIGN: Geometric comparison using bone models. METHODS: Rotational osteotomies were made in the proximal metaphysis of artificial tibias at 0 degrees, 10 degrees, 20 degrees, -10 degrees, and -20 degrees from perpendicular with respect to either the proximodistal and craniocaudal tibial axes. Negative-numbered angles represented osteotomies made from distal to proximal or caudal to cranial. Changes in tibial angulation and torsion were measured using a 3-dimensional digitizing instrument at tibial plateau rotation angles from 0 degrees to 30 degrees at 5 degrees increments. Two osteotomy reduction techniques were used: complete osteotomy reduction and alignment of the medial cortex. The mean of 5 measurements of torsional and angular tibial deformity for each of the 9 osteotomy orientations in each reduction technique group was obtained. RESULTS: All had increasing angular and rotational deformity as tibial plateau rotation angle increased. In the medially aligned cortex group, all tibias had valgus deformity, and 8 of 9 tibias were internally rotated. In the reduced osteotomy group, minimal angular deformity was seen in tibias with osteotomy variation along the proximodistal axis; however, tibias with osteotomy variation along the craniocaudal axis had angular deformity ranging from 6.0 degrees of varus deformity to 14.3 degrees of valgus deformity. Rotational deformity was affected similarly by osteotomy variation along either axis. Reduction technique had greater affect on angular and rotational deformity than osteotomy angle variation. CLINICAL RELEVANCE: These results suggest that osteotomy reduction may play a greater role in angular and rotational deformity than osteotomy angle, although extreme osteotomy angles should be avoided. To decrease the severity of deformity, we recommend that the osteotomy be made perpendicular to the craniocaudal and proximodistal axes and be completely reduced with less regard for alignment of the medial cortex.     

Influence of limb positioning and measurement method on the magnitude of the tibial plateau angle

OBJECTIVE: To evaluate the effect of limb positioning and measurement technique on the magnitude of the radiographically determined tibial plateau angle (R-TPA). STUDY DESIGN: In vitro study, R-TPA was determined by 6 blinded observers and image measurement software. ANIMALS: Five canine cadaver hind limbs. METHODS: The legs were positioned on a custom-made positioning device simulating a radiographic tabletop technique in lateral recumbency. True lateral positioning was defined by superimposition of femoral and tibial condyles on the radiographic projection. Radiographs were taken while the specimens were relocated in a proximal, distal, caudal, and cranial direction with respect to the radiographic beam. For each specimen, 25 different radiographic views were obtained and 6 blinded observers determined the radiographic TPA using 2 different methods. The conventional method used precise anatomic landmarks to determine the tibial plateau. To simulate osteoarthritic changes complicating identification of these landmarks, the tangential method estimated the tibial plateau as the tangent to the central portion of the tibial plateau. After periarticular soft tissue dissection the anatomic tibial plateau angle (A-TPA) was determined. The A-TPA and the R-TPA were compared. RESULTS: The R-TPA significantly decreased as limb position with respect to the X-ray beam changed from cranial proximal to caudal distal. The maximal mean radiographic R-TPA difference was 3.6 degrees with the first and 5.7 degrees with the second method. Regardless of the method used there was no significant difference between A-TPA and R-TPA in the true lateral position. In the peripheral positions, however, significant differences between anatomic and radiographic TPA were seen. CONCLUSIONS: Limb positioning influenced the radiographic appearance of the tibial plateau and the magnitude of the measured TPA. Cranial and proximal positioning of the limb relative to the X-ray beam leads to overestimation whereas caudal and distal positioning leads to underestimation of the TPA. CLINICAL RELEVANCE: True lateral positioning of the tibia defined by superimposition of the femoral and tibial condyles should be used for accurate TPA determination before tibial plateau leveling osteotomy.     

Growth dynamics of the canine proximal tibial physis

Objective: To determine growth of the proximal tibial physis in the Labrador Retriever, a breed of dog at risk for rupture of the cranial cruciate ligament (CCL). Animals: Male Labrador Retriever dogs (n=6). Methods: Tantalum markers (0.5 mm diameter) were implanted in the right proximal tibial epiphysis and metaphysis of each dog at 16 weeks of age. Lateral and craniocaudal radiographic projections of the tibia were made monthly and longitudinal growth was assessed from radiographs; a growth curve was generated from the data. Data from dogs that had undergone proximal tibial epiphysiodesis (PTE) was compared with the growth curve to demonstrate if the growth curve accurately predicted changes in the growth associated with this procedure. Results: Growth rate of individual dogs decreased slowly and non‐linearly over the 1st year of age. Growth from the proximal tibial physis is described. Conclusions: Growth of individual dogs described here follows the model of saltation and stasis. The growth curve generated predicted the change in tibial plateau angle (TPA) for two Labrador Retrievers that had PTE (±1°).     

Tibial plateau symmetry and the effect of osteophytosis on tibial plateau angle measurements

A novel technique was developed to estimate the caudal medial tibial plateau landmark in the face of osteophytosis to improve accuracy in tibial plateau angle measurements. Using this technique, tibial plateau angles were evaluated in 31 normal dogs before and 8 months after right cranial cruciate ligament transection. There was no significant difference in mean tibial plateau angle before or after induction of osteophytosis. Additionally, it was determined that 90% of dogs had a difference of =2 degrees between right and left tibial plateau angles, which was considered symmetrical.     

Combination tibial plateau leveling osteotomy and transverse corrective osteotomy of the proximal tibia for the treatment of complex tibial deformities in 12 dogs

Objective: To describe a surgical technique, and outcome, for treatment of proximal tibial deformity (varus, valgus, excessive tibial plateau angle [eTPA], tibial torsion and patellar luxation) by combined tibial plateau leveling osteotomy (TPLO) and transverse corrective osteotomy. Study Design: Cases series. Animals: Dogs (n=12; 19 stifle joints). Methods: Medical records of dogs that had combination TPLO and transverse corrective osteotomy, were reviewed. Pre‐ and postoperative tibial angulation, tibial torsion, tibial plateau angle (TPA), corrective osteotomy technique, method of fixation, and complications were recorded. In hospital re‐evaluation of limb function and alignment and length of time to radiographic healing were reviewed. Long‐term outcome was assessed by visual analog scale (VAS) questionnaire and owner telephone interview. Results: Proximal tibial varus or valgus was present in 68.4%; 73.7% had eTPA; and 47.4% had both. Medial patellar luxation (MPL) was present in 57.9%, of which 47.4% had tibial tuberosity displacement. Severe tibial torsion was present in 68.4%. Mean pre‐ and postoperative TPA was 37.5° and 5.7°, respectively. The mean postoperative mechanical medial proximal tibial angle (mMPTA) and mechanical medial distal tibial angle (mMDTA) were 92.2° (range, 88–96°) and 96.1° (range, 94–101°), respectively. Postoperative surgical complications were documented in 21.0%, which included implant loosening or breakage (5.3%), seroma (5.3%), septic arthritis (5.3%), and infection of the proximal tibia (5.3%). All complications were considered major because they required additional surgery. Mean time to document radiographic healing was 10.4 weeks. In‐hospital re‐evaluation of lameness was obtained at the same time; 82.4% were not lame or had a mild lameness, 17.6% had severe lameness (2/3 with infection). The VAS evaluation revealed excellent results and owner satisfaction in all ten dogs in which long‐term follow‐up was obtained. Conclusions: Long‐term clinical outcome of combination TPLO and transverse corrective osteotomy was excellent, and had a high owner satisfaction. Healing times were comparable to standard TPLO with a similar complication rate.     

Management of laterally displaced proximal tibial physeal fractures in three dogs

Fractures of the proximal tibial physis are uncommon in dogs, and are rarely associated with marked instability and lateral displacement of the proximal tibial epiphysis. Three dogs with proximal tibial physeal fractures demonstrating marked instability and lateral displacement were treated with two different principles of fixation. Healing of the physeal fracture was achieved with rigid internal fixation in one case, and with adaptational osteosynthesis supplemented with a temporary transarticular external skeletal fixator in two cases. Duration of surgery and technical difficulty was reduced using a modified adaptational osteosynthesis approach, suggesting that surgical treatment of these uncommon and challenging fractures may be more appropriately achieved by this technique.     

Caudal proximal tibial deformity and cranial cruciate ligament rupture in small-breed dogs

Eight dogs presented with chronic hindlimb lameness associated with cranial cruciate ligament rupture. Seven were small terriers. A caudal deformity of the proximal tibial shaft, originating at the proximal tibial physis, and an excessive caudal slope of the tibial plateau were present bilaterally in all dogs. The deformity was thought to be responsible for the cranial cruciate ligament failure and poor response to conservative management. Tibial plateau angles were in excess of 26 degrees in all dogs. The lameness was bilateral in three dogs. There was complete cranial cruciate ligament rupture in seven stifles and partial rupture in four. There were no meniscal injuries. Surgical correction resulted in a significant improvement (P<0.0001) in all dogs, with a mean follow-up of 12 months (range three to 24 months). There were no complications.     

Cranial cruciate ligament rupture in small dogs (<15 kg): a narrative literature review

Small breed dogs (<15 kg) affected by cranial cruciate ligament rupture secondary to cranial cruciate ligament disease are usually middle-aged (mean age at presentation: 5.4 to 9.8 years); terrier breeds, miniature and toy poodles are over-represented. Small breed dogs have a different morphology of the proximal tibia compared to medium and large breed dogs with a steep tibial plateau angle (mean tibial plateau angle 28.8° to 36.3°), absent base of the flare of the tibial tuberosity and a caudally bowed fibula. There is a lack of evidence regarding the optimal management of cranial cruciate ligament rupture in small dogs. The treatment options consist of conservative management, extracapsular stabilisation, cranial closing wedge ostectomy, tibial plateau levelling osteotomy and tibial tuberosity advancement. The limited evidence available shows that conservative management is likely to result in prolonged recovery time (average time to recovery approximately 4 months). There is paucity of reports focussing on extracapsular stabilisation in small breed dogs, and questions have been raised regarding the early failure of the extracapsular suture subject to higher loads due to the steep tibial plateau angle of small breed dogs. Cranial closing wedge ostectomy and tibial plateau levelling osteotomy have been reported to have low major complication rates and good subjective outcomes. It is controversial whether tibial tuberosity advancement is a suitable technique in dogs with steep tibial plateau angle, which includes most small breed dogs.     

Proximal tibial epiphysiodesis to reduce tibial plateau slope in young dogs with cranial cruciate ligament deficient stifle

The purpose of this study was to evaluate the ability of proximal tibial epiphysiodesis to reduce the tibial plateau slope in young dogs with cranial cruciate ligament (CCL) deficient stifles. Of the 14 treated dogs, eight had a bilateral injury, for a total of 22 joints. After physical and radiographical examination and measurement of tibial plateau slope, all of the dogs underwent surgery. Insertion of the screw was placed in the most proximal part of the tibial plateau, in its medio-lateral centre, aiming to the tibial shaft and using a K wire predriven as a guide; correct position of the screw was confirmed with intraoperative fluoroscopy or radiography. In all of the dogs the tibial slope was decreased at the time of physis fusion and the degree of change depended on the age and the breed of the dog at the time of surgery. The minimum change was 4 degrees and the maximum was 24 degrees. There was a statistically significant difference between tibial slope measured before surgery compared to tibial slope measured at the last follow-up visit after surgery. This study shows that the partial proximal tibial fusion in dogs with ACL injuries was effective in reducing the tibial slope during the residual growing time to such an extent to stabilize the joint, provided that the surgery had been carried out when there was still residual growing potential. The technique appeared to be mini-invasive and malalignment complications could be avoided by correct and precise insertion of the screw.     

Digital measurement of radiographic tibial plateau angle. A comparison to measurement on printed digital images.

Pre-operative digital radiographs from 50 dogs undergoing a tibial plateau leveling osteotomy were evaluated. Tibial plateau angles were measured directly on printed films and measured on digital images using two different commercial DICOM viewers. The radiographs were scored for osteoarthritis and positioning. Using pooled results, the mean TPA from the digital images employing Web1000 (26.47 degrees +/- 3.90) was significantly higher then the mean TPA using film radiographs (25.41 degrees +/- 3.51), or IQ-View Pro (25.48 degrees +/- 3.89). There was not a significant difference between mean TPA using radiographs or IQ-view. Digital TPA measurement using built-in angle calipers in the clinical setting is a valid technique compared to measurements from film radiographs, and produces reproducible results. However, before changing to digital measurements, the chosen software programme should be validated against measurements using film radiographs to determine the magnitude of differences.     

Combination tibial plateau leveling osteotomy and cranial closing wedge osteotomy of the tibia for the treatment of cranial cruciate ligament-deficient stifles with excessive tibial plateau angle

OBJECTIVE: To describe a surgical technique, and outcome, for treatment of cranial cruciate ligament (CrCL) deficient stifle joints with excessive tibial plateau angle (TPA) by combined tibial plateau leveling osteotomy and cranial closing wedge osteotomy (TPLO/CCWO). STUDY DESIGN: Retrospective clinical study. ANIMALS: Fifteen client-owned dogs (18 stifle joints). METHODS: Medical records of dogs that had TPLO/CCWO were reviewed. Pre- and postoperative TPA, CCWO technique, method of fixation and complications were recorded. In-hospital re-evaluation of limb function and length of time to radiographic healing was reviewed. Long-term outcome was assessed by owner telephone interview. RESULTS: Mean pre- and postoperative TPA was 42 degrees and 8 degrees, respectively. The Slocum biradial saw was used to create the CCWO in 4 stifle joints (mean postoperative TPA, 16 degrees) and a sagittal saw was used in 14 stifle joints (mean postoperative TPA, 5 degrees). Postoperative surgical complications were documented in 77.8% of cases; including patellar tendon thickening (61.1%), and implant loosening or breakage (27.8%), seroma formation (11.1%), and local irritation (11.1%). A second surgical procedure was performed in one-third of cases primarily to retrieve implants. Mean time to documented radiographic healing was 18 weeks. Final in-hospital re-evaluation of limb function (mean, 23 weeks postoperatively) was recorded as no lameness in 73.3% and mild lameness in 26.7%. All interviewed owners were satisfied with outcome and 90.9% reported marked improvement or a return to preinjury status. CONCLUSIONS: Long-term clinical outcome of TPLO/CCWO was very good in dogs with excessive TPA, with high owner satisfaction. Longer healing times and a higher complication rate were observed compared with TPLO alone. CLINICAL RELEVANCE: TPLO/CCWO of the tibia in stifle joints with excessive TPA allows for full correction of the TPA to 5 degrees without eliminating buttress support of the tibial tuberosity.     

Comparison of tibial plateau angles in dogs with and without cranial cruciate ligament injuries

OBJECTIVE: To measure and compare tibial plateau angles (TPA) of dogs with cranial cruciate ligament (CrCL) injuries and dogs without CrCL injuries. DESIGN: Prospective study. ANIMALS: 87 dogs. PROCEDURE: Stifle joints were measured from lateral radiographic views to determine TPA in 3 groups: group-1 dogs had CrCL injuries, group-1a dogs, a subgroup of group 1, had 1 unaffected stifle joint, and group-2 dogs had no CrCL injuries. Age, sex, breed, body weight, limb injured, and TPA were recorded for each dog. RESULTS: 56 stifle joints were measured in group-1 dogs; mean TPA was 23.76 degrees , and mean age and weight were 5.7 years and 37.91 kg (83.4 lb), respectively. Fourteen stifle joints were measured in group-1a dogs; mean TPA was 24.71 degrees , and mean age and weight were 5.6 years and 38.06 kg (83.8 lb), respectively. Sixty stifle joints were measured in group-2 dogs; mean TPA was 18.10 degrees , and mean age and weight of these dogs were 4.83 years and 35.85 kg (79 lb), respectively. The most common breeds included Labrador Retriever, Golden Retriever, and Rottweiler. The TPA of dogs in group 1 and group 1a were significantly greater than the TPA of dogs in group 2. CONCLUSIONS AND CLINICAL RELEVANCE: Dogs with CrCL injuries have a significantly greater TPA than dogs without CrCL injury. With further investigation, a normal TPA can be determined. In the future, TPA measurements may be used to screen dogs suspected of being susceptible to CrCL injury.     

In vitro comparison of tibial plateau leveling osteotomy with and without use of a tibial plateau leveling jig

OBJECTIVE: To evaluate the influence of a tibial plateau leveling jig on osteotomy orientation, fragment reduction, and postoperative tibial plateau angle (TPA) during tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: In vitro experimental study. ANIMALS: Large-breed canine cadavers (n=20). METHODS: TPLO was performed on 40 hindlimbs using 4 methods. Group 1: Jig; dogs in dorsal recumbency with the osteotomy parallel to the distal jig pin. Groups 2-4: No jig; dogs in lateral recumbency with the osteotomy in a vertical orientation (group 2: tibia parallel to the table top; group 3: controlled superimposition of the femoral condyles; group 4: internal rotation of the tibia). Postoperative TPA, fragment reduction, and osteotomy orientation relative to the tibial plateau were compared. Positive or negative values denoted deviation from parallel relative to the tibial plateau. RESULTS: Postoperative TPA, fragment reduction, and proximodistal osteotomy orientation were not significantly different between groups. Craniocaudal osteotomy orientation was significantly different (P<.005) from the tibial plateau. Median deviations were -4.0 degrees (group 1), 11.8 degrees (group 2), 11.2 degrees (group 3), and 0.2 degrees (group 4). Group 1 was not significantly different from group 4. CONCLUSIONS: A jig is not essential for osteotomy orientation, tibial plateau rotation, or fragment reduction. Comparable results were achieved performing a vertical osteotomy with the tibia slightly internally rotated (10 degrees -15 degrees) and parallel to the table surface. CLINICAL RELEVANCE: TPLO without use of a jig reduces surgical trauma, is less time consuming, and reduces cost.     

Tibial plateau leveling osteotomy and cranial closing wedge ostectomy in a cat with cranial cruciate ligament rupture

A 5-year-old domestic shorthair cat was presented for a nonweight-bearing left pelvic-limb lameness. Orthopedic and radiographic examinations revealed a cranial cruciate ligament rupture and deformity of the proximal tibial metaphysis. The deformity of the proximal tibia resulted in an exaggerated tibial plateau angle of approximately 75 degrees. Surgical correction was performed with a combination of tibial plateau leveling osteotomy and cranial closing wedge ostectomy. The procedures resulted in an excellent clinical outcome with immediate return to weight bearing in the operated limb and progressive improvement in function over the ensuing 4 months.     

Angle between the patellar ligament and tibial plateau in dogs with partial rupture of the cranial cruciate ligament

OBJECTIVE: To measure the angles between the patellar ligament and the tibial plateau and between the patellar ligament and the common tangent at the tibiofemoral contact point (TFCP) in stifle joints of dogs with partial rupture of the cranial cruciate ligament (CrCL) for comparison with data obtained for stifle joints in dogs with intact CrCLs. SAMPLE POPULATION: 60 stifle joints of 54 dogs with surgically confirmed partial CrCL rupture. PROCEDURES: Mediolateral radiographic views of the stifle joints were obtained, and the angles between the patellar ligament and the conventionally defined tibial plateau (angle gamma) and between the patellar ligament and the common tangent to the TFCP (angle alpha) were measured at incidental stifle joint flexion (angle beta) by 2 independent observers. Data underwent linear regression analysis and were compared with findings in joints of dogs without degenerative joint disease. RESULTS: In stifle joints of dogs with a partial rupture of the CrCL, angles gamma and alpha were 5 degrees and 2 degrees larger than each corresponding angle in healthy canine joints. At 100 degrees of flexion, the patellar ligament was perpendicular to the conventionally defined tibial plateau. At 110 degrees of flexion, the patellar ligament was perpendicular to the common tangent at the TFCP. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs, stifle joints with partially ruptured CrCLs have marginally larger angles between the patellar ligament and the tibial plateau, compared with joints with intact CrCLs; at equivalent angles of flexion, comparatively greater shear force affects the CrCLs in stifle joints with partial CrCL ruptures.