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.     

Change in tibial plateau angle after tibial plateau leveling osteotomy in dogs

OBJECTIVE: To determine the change in tibial plateau angle (TPA) during healing after tibial plateau leveling osteotomy (TPLO) performed for cranial cruciate ligament insufficiency in dogs and to examine factors that may be associated with the change. STUDY DESIGN: Retrospective study. STUDY POPULATION: One hundred and forty-nine canine stifles after TPLO procedure. METHODS: Records of dogs that had TPLO were reviewed. Patient age, weight, sex, breed, pre- and postoperative TPA, recheck TPA, time to recheck, type of implant used, and radiographic evidence of healing were analyzed. RESULTS: Mean time to recheck evaluation was 46 days (range, 28-65 days). Mean difference between immediate postoperative and recheck TPA measurements was 1.5 degrees (range, -3 to 9 degrees). Recheck TPA was a significantly greater (numerically higher) than immediate postoperative TPA (P<.0001). There was no significant effect of patient weight, type of plate used, or healing status of the osteotomy at the time of recheck. No correlation between pre- or postoperative TPA angles and change in TPA angle was detected. CONCLUSIONS: TPA changes during osteotomy healing after TPLO, but factors influencing this change were not identified. CLINICAL RELEVANCE: TPA may increase during healing after TPLO despite apparently adequate osteotomy fixation. The clinical relevance of this increase is unknown but is likely minimal.     

A comparison of outcomes following tibial plateau levelling osteotomy and cranial tibial wedge osteotomy procedures.

The objective of this study was to determine whether clinical outcomes were superior and complication rates were lower in dogs that had had a cranial cruciate ligament rupture treated by tibial plateau levelling osteotomy (TPLO), compared to those dogs that had been treated using the original cranial tibial wedge osteotomy (CTWO) procedure. Thirty-seven client-owned dogs with cranial cruciate ligament rupture were included in the study: 19 dogs underwent a TPLO procedure, and 18 dogs underwent a CTWO procedure. The study was retrospective, with the data being obtained from medical records and a review of radiographs. The long-term outcome was assessed by means of an owner questionnaire using a visual analogue scale. For the majority of factors that were reviewed, there was not a significant difference in outcome between the dogs that had a TPLO or those that had undergone a CTWO. All of the dogs showed a rapid return to weight bearing after surgery, and at the six week re-examination, the majority of the dogs did not have any pain on stifle palpation. They displayed a good stifle range of motion and significantly lower lameness scores than those prior to surgery. The complication rates did not differ between the procedures, however, within this small sample of dogs, complications following a CTWO were more likely to require revision surgery.     

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.     

Proximal tibial intraarticular ostectomy for treatment of canine cranial cruciate ligament injury

OBJECTIVE: To report a technique for surgical alteration of the slope of the tibial plateau by a proximal tibial intraarticular ostectomy (PTIO) after injury to the canine cranial cruciate ligament (CCL) and to determine the outcome. STUDY DESIGN: Prospective clinical study. ANIMALS: Dogs (n=52) with CCL injury in 60 stifle joints. METHODS: CCL injury was treated by lateral stifle arthrotomy, removal of CCL remnants, and appropriate meniscal surgery. PTIO was performed to remove a wedge of bone from the proximal aspect of the tibia. The ostectomy site was reduced and stabilized using a bone plate and screws applied to the medial surface of the tibia as well as a craniocaudal positional screw. Dogs were evaluated at 6 weeks, 6, and 12 months by complication assessment, lameness scores, stifle range of motion (ROM), thigh circumference, radiographic assessment, degenerative joint disease (DJD) scores, and surgeon and owner evaluation of function. RESULTS: Lameness scores improved by 6 and 12 months in all but 1 dog. Thigh circumference and DJD were increased at 6 and 12 months. Complications occurred in 20% of dogs with all but 1 occurring perioperatively or within 6 weeks; most common were injury to the long digital extensor tendon (4 dogs) and plate failure (3); 2 other dogs required surgery to treat complications. Most owners (98%) reported that lameness had improved by 12 months; 90% were extremely or very satisfied with the procedure and 90% would have the same procedure performed on another dog. CONCLUSION: PTIO to level the tibial plateau provided a satisfactory clinical outcome in dogs >20 kg with CCL injury and the complication rate was similar to tibial plateau levelling osteotomy (TPLO). Stifle osteoarthritis continued to progress radiographically. CLINICAL RELEVANCE: PTIO represents an alternative to TPLO that does not require specialized surgical equipment.     

Kinematic gait analysis of the hind limb after tibial plateau levelling osteotomy and cranial tibial wedge osteotomy in ten dogs

This study identifies and compares the kinematic gait changes occurring in tibial plateau levelling osteotomy (TPLO) and cranial tibial wedge osteotomy (CTWO) limbs after transection of the cranial cruciate ligament (CrCL). Ten, healthy, adult beagle dogs were assigned to TPLO (five dogs) and CTWO (five dogs) groups. Hind limb kinematics were assessed, while dogs were trotted at speeds ranging from 2.0 to 2.3 m/s. The animals were evaluated preoperatively (prior to TPLO and CTWO surgery) and at both 8 and 12 weeks after surgery. Two-dimensional evaluation was synchronized to obtain the three-dimensional coordinates using the APAS motion analysis software. Gait patterns were assessed by measuring stifle, tibiotarsal joint angles and stifle joints angular velocity. Stifle and tibiotarsal joint functions were not affected by TPLO surgery, but stifle and tibiotarsal joint angles were changed, following CTWO surgery, compared with their preoperative values. The angular velocity patterns of CTWO were characterized by increased stifle joint extension velocity from the middle to end swing phase and decrease in the peak velocities (flexion) during swing phase. None of these changes was observed in the stance phase after the CTWO surgery. These kinematic results showed that dogs that underwent a CTWO procedure were more likely to have significantly hyperextended gait patterns of the swing phase postoperatively than the dogs that had a TPLO procedure for repair of a ruptured CrCL.     

Effects of early intensive postoperative physiotherapy on limb function after tibial plateau leveling osteotomy in dogs with deficiency of the cranial cruciate ligament

OBJECTIVE: To determine effects of early intensive postoperative physiotherapy on limb function in dogs after tibial plateau leveling osteotomy (TPLO) for deficiency of the cranial cruciate ligament (CCL). ANIMALS: 8 adult dogs with CCL deficiency. PROCEDURE: After TPLO, dogs underwent a physiotherapy program 3 times/wk (physiotherapy group; n = 4) or a walking program (home-exercise group; 4). All dogs were evaluated before surgery, 1 and 10 days after surgery, and 3 and 6 weeks after surgery. Thigh circumference (TC), stifle joint flexion and extension range of motion (ROM), lameness, and weight-bearing scores were recorded. RESULTS: Before surgery, CCL-deficient limbs had significantly reduced TC and reduced flexion and extension ROMs, compared with values for the contralateral control limb. Six weeks after TPLO, the physiotherapy group had significantly larger TC than the home-exercise group, with the difference no longer evident between the affected and nonaffected limbs. Extension and flexion ROMs were significantly greater in the physiotherapy group, compared with values for the home-exercise group, 3 and 6 weeks after surgery. Six weeks after surgery, the difference in flexion and extension ROMs was no longer evident between the affected and nonaffected limbs in the physiotherapy group. Both groups had improvements for lameness and weight-bearing scores over time, but no difference was found between the 2 groups. CONCLUSIONS AND CLINICAL RELEVANCE: After TPLO in CCL-deficient dogs, early physiotherapy intervention should be considered as part of the postoperative management to prevent muscle atrophy, build muscle mass and strength, and increase stifle joint flexion and extension ROMs.     

Anatomic femorotibial changes associated with tibial plateau leveling osteotomy

This prospective study evaluated anatomic femorotibial changes utilizing the relationship between the intercondylar notch and the intercondylar eminence following tibial plateau leveling osteotomy (TPLO). We hypothesized that TPLO results in anatomic alteration of the femorotibial joint. Pre- and post-operative computed tomography (CT) scans of cranial cruciate deficient stifle joints treated with TPLO were performed on 25 client-owned dogs. Computed tomography scans were performed at 3 different stifle angles: extension, 135° walking angle, and 90° of flexion. Tibial plateau leveling osteotomy did not result in a significant medial or lateral shift of the intercondylar eminence relative to the intercondylar notch. There was a significant cranial shift of the intercondylar eminence with the stifle in extension following TPLO. In addition, TPLO resulted in a significantly narrowed femorotibial joint space. The biomechanical effects of TPLO and medial meniscal release need to be further defined.     

Incidence of motion loss of the stifle joint in dogs with naturally occurring cranial cruciate ligament rupture surgically treated with tibial plateau leveling osteotomy: longitudinal clinical study of 412 cases

OBJECTIVE: To report the incidence of loss of stifle extension or flexion and its relationship with clinical lameness after tibial plateau leveling osteotomy (TPLO) for treatment of cranial cruciate ligament (CCL) rupture. STUDY DESIGN: Longitudinal study. ANIMALS: Dogs (n=280) with CCL rupture (n=412). METHODS: TPLO was performed without meniscal release or arthrotomy. Angles of extension and flexion of the stifle were measured by goniometry to determine range of motion. Based upon motion loss, stifles were divided in 3 groups: no loss of extension or flexion (n=322), <10 degrees loss of extension or flexion (n=78), > or =10 degrees loss of extension or flexion (n=12). RESULTS: Loss of extension or flexion > or =10 degrees was associated with significantly (P=.001) higher clinical lameness scores in comparison with no loss, or loss of extension or flexion <10 degrees. Osteoarthrosis in the cranial femorotibial joint was significantly correlated (P<.005, r(2)=0.55) with loss of extension. Loss of extension > or =10 degrees was less tolerable and less amenable to physical rehabilitation than flexion loss. CONCLUSIONS: Loss of extension or flexion > or =10 degrees was responsible for higher clinical lameness scores. Osteoarthrosis in the cranial femorotibial joint led to extension loss. CLINICAL RELEVANCE: Loss of extension or flexion should be assessed in dogs with persistent clinical lameness after TPLO so that early intervention can occur. Our study provides guidelines to define clinically relevant loss of extension or flexion of stifle joint after TPLO.     

Pre- and postoperative force plate analysis of dogs with experimentally transected cranial cruciate ligaments treated using tibial plateau leveling osteotomy

Objective— Quantitative and objective assessment of hindlimb kinetics after cranial cruciate ligament (CrCL) transection and subsequent stifle stabilization using the tibial plateau leveling osteotomy (TPLO) in normal dogs.
Study Design— In vivo experimental biomechanical evaluation.
Animals— Six healthy adult foxhounds.
Methods— Dogs were screened by orthopedic and radiographic examination before study entry. Force plate analysis of gait was measured before extirpation of the right CrCL and TPLO and again at 8 and 18 weeks after surgery.
Results— There was a significant decrease in peak vertical forces (PVFs) and vertical impulse (VI) of the treated hindlimb at 8 weeks when compared with preoperative and 18-week measurements. When compared with preoperative values, there was no significant difference in 18 week PVF and VI in dogs that had TPLO.
Conclusion— TPLO can restore kinetic measures of limb function at 18-weeks after surgery when compared with preoperative values after experimental transection of the CrCL in dogs.
Clinical Relevance— TPLO induces lameness that returns to near normal at 18 weeks. The severity and duration of lameness was similar to that reported for other experimental models of stifle instability repaired by different techniques.     

The effect of tibial plateau leveling osteotomy position on cranial tibial subluxation: an in vitro study

OBJECTIVES: To compare centered versus distal tibial plateau leveling osteotomy (TPLO) position on cranial tibial subluxation, postoperative tibial plateau angle (TPA), and tibial long axis shift (TLAS). STUDY DESIGN: In vitro biomechanical evaluation. ANIMALS: Six pairs of canine cadaveric hind limbs. METHODS: One limb of each pair was randomly assigned to the distal (TPLO-D) or centered (TPLO-C) osteotomy group. Cranial tibial subluxation (CTS) under load was quantified sequentially under 3 conditions: intact, after cranial cruciate ligament transection, and after TPLO; a corrected CTS value was also calculated. Postoperative TPA and TLAS were measured. Comparisons were made using 1-way repeated measures ANOVA with a Tukey's multiple comparison post hoc test for CTS, and a Wilcoxon's sign rank test for TPA and TLAS. Significance was set at P<.05. RESULTS: TPLO-C had a significantly lower mean CTS than TPLO-D (P<.01). Corrected CTS was also significantly lower in TPLO-C than in TPLO-D (P<.001). Postoperative TPA and TLAS were less in TPLO-C than in TPLO-D (P=.0312). CONCLUSION: Our results confirm that distal centering of the TPLO leads to craniodistal translation of the tibial plateau, TLAS, and a postoperative TPA that is greater than expected. This geometric effect has the biomechanical effect expected of inadequate tibial plateau leveling, namely incomplete neutralization of cranial tibial thrust. CLINICAL RELEVANCE: The centered osteotomy position is geometrically more precise, and biomechanically more effective than the distal position.     

The effect of tibial plateau angle on ground reaction forces 4-17 months after tibial plateau leveling osteotomy in Labrador Retrievers

OBJECTIVE: To assess the relationship between postoperative tibial plateau angle (TPA) and ground reaction forces (GRFs) in Labrador Retrievers at least 4-months after tibial plateau leveling osteotomy (TPLO) surgery. STUDY DESIGN: A retrospective longitudinal study. ANIMALS: Thirty-two Labrador Retrievers with unilateral cranial cruciate ligament disease that had TPLO and concurrent meniscal surgery. METHODS: TPA and GRFs were measured pre- and > or = 4 months postoperatively. Preoperative GRFs, preoperative TPA, duration of injury, postoperative TPA and degree of rotation were each compared with postoperative GRFs using correlation analysis. Dogs were also grouped by postoperative TPA and compared using 1-way analysis of variance (ANOVA). Postoperative function was compared with meniscal release/meniscectomy, patient age, sex, body weight and follow-up time using ANOVA. RESULTS: No significant relationship was found between preoperative GRFs, preoperative TPA, duration of injury, postoperative TPA, degree of rotation, or meniscal release/meniscectomy and postoperative function. Mean preoperative GRFs for all dogs were 28.8 +/- 9.5 for peak vertical force (PVF) and 9.3 +/- 3.1 for peak vertical impulse (VI). Mean postoperative GRFs for all dogs were 40.4 +/- 5.0 for PVF and 14.1 +/- 1.9 for VI. CONCLUSIONS: No statistically significant relationship was found between postoperative TPA and GRFs after TPLO > or = 4 months after surgery, where the postoperative angle was between 0 and 14 degrees. No significant relationship was found between the preoperative TPA and postoperative function. CLINICAL RELEVANCE: Limb function in Labrador Retrievers was not affected by postoperative TPA and re-operation for cases with a postoperative TPA between 0 and 14 degrees is not recommended.     

Biomechanics of tibial plateau leveling of the canine cruciate-deficient stifle joint: a theoretical model

OBJECTIVE: To evaluate the effect of tibial plateau leveling on the biomechanics of the canine stifle. STUDY DESIGN: Analysis of a 3-dimensional (3-D) anatomically accurate theoretical model of the canine stifle. METHODS: A 3-D, 3-segment mathematical model of the normal canine stifle was modified to simulate the effect of rotation of the tibial plateau during tibial plateau leveling osteotomy (TPLO). The model examined the normal stifle, the stifle with a tibial plateau angle (TPA) of 0 degrees, and the stifle with a TPA of 5 degrees. Analysis of the models at 10 consecutive equally spaced positions during the stance phase yielded data such as ligament forces and joint reaction forces at each position. RESULTS: Rotation of the tibial plateau to a TPA of 0 degrees almost eliminates forces in the cranial cruciate ligament (CCL) throughout the stance phase. Rotation to a TPA of 5 degrees did not, however, substantially decrease the load in the CCL. Both procedures increased the load in the caudal cruciate ligament (CaCL). CONCLUSIONS: Cranial tibial thrust (CTT) is converted into caudal tibial thrust when the TPA is 0 degrees ; however, rotating the plateau to a TPA of 5 degrees does not eliminate the CTT. CLINICAL RELEVANCE: The TPLO procedure performed as currently recommended (rotating the tibial plateau to a TPA of 5 degrees) may not eliminate the CTT, but only reduce it. Both TPLO procedures evaluated here were found to increase the load in the CaCL.     

Comparison of surgical treatment options for cranial cruciate ligament disease in large-breed dogs with excessive tibial plateau angle

Objective— To identify surgical techniques performed by veterinary surgeons for the treatment of cranial cruciate ligament disease in large-breed dogs with excessive tibial plateau angle (eTPA), compare their outcomes, identify risk factors for postoperative complications, and compare outcome and complication rate with tibial plateau leveling osteotomy (TPLO) in dogs without eTPA.
Study Design— Multicenter, case–control study.
Animals— eTPA group (TPA≥35°)=58 dogs (78 stifles); control group (TPA≤30°)=58 dogs (72 stifles).
Methods— Control and eTPA group dogs were identified. Medical records, radiographic reviews, and pet-owner interviews were used to identify surgical treatments performed, their complications, and outcome. Odds ratios with 95% confidence intervals, χ² tests, and t-tests were calculated to discern differences between eTPA and control-group dogs.
Results— TPLO was the most common treatment for eTPA. Owner-perceived outcome was superior for eTPA group dogs when TPLO resulted in TPA≤14° compared with those with postoperative TPA>14°. Loss of tibial plateau leveling during convalescence was the most commonly observed major complication; addition of ancillary implants to TPLO significantly reduced its incidence. Postoperative complications were more common in dogs with eTPA than in dogs without eTPA; however, no difference in owner-perceived outcome was identified.
Conclusions— Surgical treatment of dogs with eTPA has a higher complication rate, but comparable outcome to that of dogs without eTPA.
Clinical Relevance— Postoperative TPA≤14° and addition of ancillary implants are recommended when using TPLO to treat dogs with eTPA.     

Risk factors for tibial tuberosity fracture after tibial plateau leveling osteotomy in dogs

Objective— To evaluate factors that predispose to tibial tuberosity (TT) fracture after tibial plateau leveling osteotomy (TPLO) in dogs.
Study Design— Retrospective study.
Animals— Dogs (n=182) with cranial cruciate ligament (CCL) rupture undergoing 213 TPLO surgeries.
Methods— Medical records and radiographs of 2 groups of dogs that had TPLO surgery (2000–2001, 2004–2005) were evaluated to determine the effect of operative technique and surgeon experience on TT fracture.
Results— TT fracture was diagnosed in 8 dogs (9 TPLO, 4.2% of surgical procedures). Four fractures occurred after unilateral TPLO in 167 dogs (2.4%), 4 fractures occurred after simultaneous bilateral TPLO in 5 dogs (40%), and 1 fracture occurred after staged bilateral TPLO in 36 dogs (2.8%). Simultaneous bilateral TPLO resulted in a 12.4 times higher odds of TT fracture versus unilateral TPLO ( P =.046). The mean absolute thickness of the TT after TPLO was less in dogs sustaining TT fractures (7.2 ± 2.2 mm) than those that did not (10.8 ± 2.7 mm, P <.0001). The odds of fracture decreased by 37% when the absolute TT width postosteotomy increased by 1 mm ( P <.0001). An increase in tibial plateau angle at follow-up versus immediately postoperative was associated with TT fracture ( P =.025). Surgeon experience was not associated with TT fracture.
Conclusion— A combination of surgical decision-making and surgical technique play a role in the occurrence of TT fracture after TPLO. Simultaneous bilateral TPLO was associated with a high percentage of TT fracture.
Clinical Relevance— Careful planning of osteotomy positioning is advised while performing TPLO surgery.     

Complications with and owner assessment of the outcome of tibial plateau leveling osteotomy for treatment of cranial cruciate ligament rupture in dogs: 193 cases (1997-2001)

OBJECTIVE: To identify complications associated with tibial plateau leveling osteotomy (TPLO) for treatment of cranial cruciate ligament rupture in dogs and assess owner perceptions of outcome. DESIGN: Retrospective study. ANIMALS: 193 dogs that underwent unilateral or bilateral TPLO (253 TPLOs total) between November 1997 and March 2001. PROCEDURE: Complications associated with the surgical procedure were recorded. A questionnaire was sent to owners of all dogs to assess their perceptions of outcome. RESULTS: Complications were identified in 47 of the 193 (24.4%) dogs and in association with 52 of the 253 (20.6%) TPLOs. Dogs that underwent bilateral TPLOs during a single anesthetic episode had a higher complication rate than did dogs that underwent unilateral TPLO and dogs that underwent bilateral TPLOs during separate anesthetic episodes. Body weight, surgery time, whether a meniscal release or meniscectomy was performed, and extent of cruciate ligament damage were not associated with whether complications occurred. One hundred forty-one of 151 (93%) owners who responded to the questionnaire were satisfied with the outcome of the surgery. Assessments of outcome were not significantly different between owners of dogs that had complications and owners of dogs that did not. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that complications developed in approximately 25% of dogs undergoing TPLO for treatment of a cranial cruciate ligament injury but that most complications responded to appropriate treatment, and development of complications did not affect owner assessments of outcome. There was a higher incidence of complications when bilateral TPLOs were performed during a single anesthetic episode.     

Effect of medial meniscal release on tibial translation after tibial plateau leveling osteotomy

OBJECTIVE: To evaluate the biomechanical effects of medial meniscal release (MMR) and medial, caudal pole hemimeniscectomy (MCH) on joint stability in the cranial cruciate ligament (CCL)-deficient canine stifle before and after tibial plateau leveling osteotomy (TPLO). STUDY DESIGN: Experimental study. ANIMALS: Thirty-one dogs. METHODS: In experiment 1, 16 pairs of normal hindlimbs randomly assigned to an intact or transected CCL group were studied to determine the magnitude of tibial translation after MMR and MCH under 20% body weight load using radiographic imaging of radio-opaque markers. In experiment 2, 15 pairs of CCL-deficient hindlimbs were randomly assigned to a TPLO or sham TPLO group. The remainder of the experiment was performed as described for experiment 1. The effect of CCL transection, MMR, MCH and TPLO were analyzed using 2-way repeated measures ANOVA; P<.05 was considered significant. RESULTS: We found a greater effect of MMR on tibial translation in transected CCL stifles than in intact stifles (P=.0016). We found no further effect of MCH after MMR (P>.05). We found a greater effect of MMR in sham TPLO than TPLO stifles (P=.0013) but no further effect of MCH after MMR (P>.05). CONCLUSIONS: By resisting tibial translation the medial meniscus might be at greater risk of tearing in CCL-deficient stifles. TPLO may spare the medial meniscus by neutralizing the tibial thrust and eliminating the wedge effect of the medial meniscus. CLINICAL RELEVANCE: MMR may not be indicated in the CCL-deficient stifle stabilized by TPLO.     

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.     

Long-term radiographic comparison of tibial plateau leveling osteotomy versus extracapsular stabilization for cranial cruciate ligament rupture in the dog

OBJECTIVE: Comparison of 2 methods of surgical management of cranial cruciate ligament (CCL) injury in large-breed dogs using a radiographic osteoarthrosis (OA) scoring system. STUDY DESIGN: Retrospective study. ANIMALS: Client-owned dogs (n=66). METHODS: Radiographs were evaluated from dogs weighing >/=22.7 kg, with surgical management of CCL rupture using extracapsular repair (ECR) or tibial plateau leveling osteotomy (TPLO). Radiographs were taken immediately before surgery and >/=12 months later. An OA score was assigned to each set of radiographs taken at the preoperative and final examinations by evaluating 32 specific features of stifle OA. The difference between preoperative and final OA scores were subtracted and 2 final score categories of a change 5 were created. A logistic regression model was used to evaluate the effect of right versus left pelvic limb, age, preoperative weight, postoperative weight, days from surgery until final radiographic recheck, cranial cruciate status at surgery, medial meniscus status at surgery, and ECR versus TPLO. RESULTS: The ECR group had 27 stifles (22 dogs) and the TPLO group had 52 stifles (44 dogs). ECR dogs had a preoperative weight of 33.4+/-9.3 kg (range 22.7-54.1 kg) and a preoperative OA score of 13.0+/-8.4 (range 1-34) compared with TPLO dogs that had a preoperative weight of 38.9+/-9.1 kg (range 25-63.9 kg) and preoperative OA score of 15.9+/-8.4 (range 4-44). Postoperative weights for ECR and TPLO dogs were 33.6+/-9 kg (range 21.8-54.6 kg) and 39.4+/-10.1 kg (range 24-72 kg), respectively. Final OA scores were: ECR dogs, 26.3+/-10.8 (range, 10-54); TPLO dogs, 23.3+/-9.5 (range, 12-50). Dogs with a final change in OA score of >/=6 were 5.78 times more likely to have had ECR compared with those that had TPLO as stabilization procedure (odds ratio=5.78; Log-likelihood test P-value=.025). Other dependent variables were not significant. CONCLUSIONS: Based on logistic regression analysis, dogs with larger OA score differences were 5.78 times more likely to have had ECR than TPLO. CLINICAL RELEVANCE: Prospective, randomized surgical trials with pre-defined objective measures would be required to further evaluate the clinical importance of these preliminary findings which suggest that TPLO may help stabilize the cranial tibial thrust as originally proposed.     

Short-term and eight to 12 months results of a tibial tuberosity advancement as treatment of canine cranial cruciate ligament damage

OBJECTIVE: To describe the perioperative complications and the six weeks and eight to 12 months outcome of cases of canine cranial cruciate ligament damage treated with a tibial tuberosity advancement. METHODS: The medical records including the six weeks' postoperative re-evaluation and radiographs of dogs with a tibial tuberosity advancement (70 operated stifles) were analysed regarding the short-term outcome and the recorded complications. A questionnaire for the evaluation of the eight to 12 months outcome was sent to the owners and the answers tabulated. RESULTS: The complication rate was comparable with previous reports of cranial cruciate ligament rupture treated with a tibial tuberosity advancement or a tibial plateau leveling osteotomy (TPLO). The most frequent complication was a symptomatic late secondary meniscal damage in six cases (8.5 per cent). These cases were successfully treated with a partial meniscectomy during a minimal invasive procedure. The six-week re-evaluation showed advanced healing of the tibial crest osteotomies in 94 per cent of the cases and a significant reduction of the lameness in all dogs. Eighty-three per cent of the owners reported that their dogs are never lame or only after heavy exercise eight to 12 months after the tibial tuberosity advancement procedure. Sixty-five per cent of the owners stated the overall treatment to be excellent, 28 per cent good. CLINICAL SIGNIFICANCE: The six weeks' follow-up examination and the questionnaire revealed results of the tibial tuberosity advancement comparable to previously published studies, stating that the lameness and the activity level of the patients with cranial cruciate ligament disease greatly improved after the tibial tuberosity advancement.