Effect of Medial Meniscal Release on Tibial Translation After Tibial Plateau Leveling Osteotomy

Short-term outcomes of 43 dogs treated with arthroscopic suturing for meniscal tears associated with cranial cruciate ligament disease

OBJECTIVE

To describe short-term outcomes and complications in dogs receiving meniscal suturing and concurrent tibial plateau leveling osteotomy (TPLO) with or without augmentation with an extracapsular suture.

STUDY DESIGN

Retrospective case series.

ANIMALS

Forty-three client-owned dogs submitted for cruciate ligament disease.

METHODS

Dogs were included if meniscal suturing was performed during or after a TPLO procedure. Criteria included an unstable medial meniscus without evidence of a tear, a caudal vertical longitudinal tear with or without displacement, or if a bucket-handle tear was debrided and the remaining rim was unstable. Stifle stabilization was performed by either a standard TPLO or an augmented TPLO (TPLO + internal brace [IB]). Outcome measures included physical examination findings, radiographs, subjective gait examination, Liverpool Osteoarthritis in Dogs (LOAD) scores, and second-look arthroscopy.

RESULTS

Forty-four meniscal repairs were performed in 43 dogs. Five types of meniscal tears were treated employing eight suture materials. Complications were documented in 15 cases (34%). The stabilization technique had a significant impact on the outcome (p = .049): TPLO + IB had a 93.3% success rate and the success rate was 71.4% in the TPLO-only group.

CONCLUSION

Five types of meniscal pathology were addressed successfully in the study, indicating that currently accepted criteria for meniscal suturing in dogs may be overly conservative. The majority of complications were not related to the meniscal suturing itself and did not compromise the outcome. The stifle stabilization technique had an impact on outcome.

CLINICAL SIGNIFICANCE

The authors found arthroscopic meniscal suturing to be practical and successful in this patient population. Postoperative stifle stability had an impact on successful treatment.

Multiparametric Comparison of Two TTA-Based Surgical Techniques in Dogs with Cranial Cruciate Ligament Tears

Tearing of the cranial cruciate ligament causes hindlimb lameness in dogs. Different surgical procedures have been proposed to treat this condition. In this study, two different TTA-based techniques and implants were compared. A total of 30 dogs were separated into two groups according to the technique and implant used (Porous TTA® or Model Xgen®). The aim of the study was to assess whether one of these techniques has better functional recovery of the joint, better bone consolidation after the osteotomy procedure and fewer osteoarthritic changes. We compared both groups up to 3 months after surgery. No significant differences were found in any of the assessed parameters. Thus, both procedures were found to be equally effective and safe.

Comparison of incidence of medial meniscal injury in small dogs (≤15 kg) and medium-to-large dogs (>15 kg) with naturally occurring cranial cruciate ligament disease undergoing tibial plateau levelling osteotomy: 580 stifles (2015 to 2019)

OBJECTIVES

To investigate whether a difference exists in incidence of medial meniscal tears between small (≤15 kg) and medium-to-large (>15 kg) dogs with naturally occurring cranial cruciate ligament disease.

MATERIALS AND METHODS

Records were retrospectively reviewed to identify the incidence of medial meniscal tears in dogs undergoing tibial plateau levelling osteotomy. Degree of cruciate insufficiency, method of identification (arthroscopy or arthrotomy), tibial plateau angle, weight and signalment were recorded. A two-proportion z-test with clustering adjustment was used to compare the meniscal tear rate between the two groups. Logistic regression analysis was used to investigate the effects of variables on medial meniscal tears.

RESULTS

Seventy-six stifles in 67 small dogs and 504 stifles in 384 medium-to-large dogs were included. The rate of meniscal injury at index surgery was 38.2% in small dogs and 36.7% in medium-to-large dogs. The subsequent meniscal tear rate was 1.3% in small dogs and 8% in medium-to-large dogs. The difference in meniscal tear rate was not statistically significant at either index surgery or subsequently. Degree of cruciate ligament insufficiency and use of arthroscopy were significantly associated with medial meniscal tears at index surgery. No variables were significantly associated with subsequent medial meniscal tears.

CLINICAL SIGNIFICANCE

No significant difference exists in medial meniscal tear rate between small and medium-to-large dogs either at index surgery or subsequently. The index of suspicion of concurrent medial meniscal tears should be higher in dogs with complete tear of the cranial cruciate ligament but a partial tear does not preclude meniscal pathology.

Subsequent meniscal tears following tibial tuberosity advancement and tibial plateau leveling osteotomy in dogs with cranial cruciate ligament deficiency: An in vivo experimental study

OBJECTIVE

To evaluate the short- and mid-term effects of tibial tuberosity advancement (TTA) and tibial plateau leveling osteotomy (TPLO) on subsequent meniscal tears.

STUDY DESIGN

Experimental in vivo study.

ANIMALS

Purpose-bred beagle dogs (n = 15).

METHODS

For each dog, the cranial cruciate ligaments were transected; one limb underwent TTA and the other limb underwent TPLO. Orthopedic and radiographic examinations were performed preoperatively and at 12 and 32 weeks postoperatively. Gross evaluation of the stifle joint was performed after euthanasia at 12 (n = 10) and 32 (n = 5) weeks.

RESULTS

Lameness scores were not different between TTA and TPLO limbs at any time point. Radiographic osteoarthritis scores of TTA stifles (1.33 ± 0.49) were higher than TPLO stifles (0.67 ± 0.49) (p = .002) at 12 weeks postoperatively, but there was no difference between groups at 32 weeks postoperatively. Subsequent medial meniscal tears occurred in 6/10 TTA stifles, and 0/10 TPLO stifles at 12 weeks postoperatively and in 5/5 TTA stifles, and 1/5 TPLO stifles at 32 weeks postoperatively. Subsequent lateral meniscal tears occurred in 4/5 TTA stifles at 32 weeks postoperatively. Medial meniscal total gross pathology score was higher in TTA than TPLO stifles. TTA stifles had more articular cartilage damage when compared with TPLO stifles at 32 weeks postoperatively.

CONCLUSION

In this within-dog experimental comparison, subsequent medial meniscal tears and cartilage injury was more prevalent following TTA when compared to TPLO.

CLINICAL SIGNIFICANCE

In an experimental model, TPLO protects the medial meniscus and articular cartilage better than TTA in stifles with complete cranial cruciate ligament deficiency.

Femorotibial kinematics in dogs treated with tibial plateau leveling osteotomy for cranial cruciate ligament insufficiency: An in vivo fluoroscopic analysis during walking

OBJECTIVE

To determine the ability of tibial plateau leveling osteotomy (TPLO) to address abnormal femorotibial kinematics caused by cranial cruciate ligament (CCL) rupture during walking in dogs.

STUDY DESIGN

Prospective, clinical.

ANIMALS

Sixteen dogs (20-40 kg) with unilateral complete CCL rupture.

METHODS

Lateral view fluoroscopy was performed during treadmill walking preoperatively and 6 months after TPLO. Digital three-dimensional (3D) models of the femora and tibiae were created from computed tomographic (CT) images. Gait cycles were analyzed by using a 3D-to-2D image registration process. Craniocaudal translation, internal/external rotation, and flexion/extension of the femorotibial joint were compared between preoperative and 6-month postoperative time points for the affected stifle and 6-month postoperative unaffected contralateral (control) stifles.

RESULTS

In the overall population, CCL rupture resulted in 10 ± 2.2 mm (mean ± SD) cranial tibial translation at midstance phase, which was converted to 2.1 ± 4.3 mm caudal tibial translation after TPLO. However, five of 16 TPLO-treated stifles had 4.1 ± 0.3 mm of cranial tibial subluxation during mid-to-late stance phase, whereas 10 of 16 TPLO-treated stifles had 4.3 ± 0.4 mm of caudal tibial subluxation throughout the gait cycle. Overall, postoperative axial rotational and flexion/extension patterns were not different from control, but stifles with caudal tibial subluxation had more external tibial rotation during mid-to-late stance phase compared with stifles with cranial tibial subluxation.

CONCLUSION

TPLO mitigated abnormal femorotibial kinematics but did not restore kinematics to control values in 15 of 16 dogs during walking.

CLINICAL SIGNIFICANCE

Tibial plateau leveling osteotomy reduces cranial tibial subluxation during walking, but persistent instability is common.

Relationship between the stage of osteoarthritis before and six months after tibial tuberosity advancement procedure in dogs

The present retrospective study evaluated the progression of osteoarthritis in stifle joints based on the radiographic grade of osteoarthritis (OA) scored in dogs with cranial cruciate ligament rupture. The aim of the study was to search for a correlation between the stage of radiographic osteoarthritis prior to surgery and the osteoarthritis progression occurring after the tibial tuberosity advancement (TTA) procedure. It was hypothesized that the procedure carried out in dogs in the early stages of OA could reduce the OA changes. A total of 190 X-ray images obtained from the medical records of 38 dogs were evaluated. The radiographic signs of osteoarthritis of 38 stifle joints were scored from 0 to 3 in 10 specific anatomic locations. The radiographs were divided into 4 groups based on the global scores: A) no-OA, B) mild-OA, C) moderate-OA, D) severe-OA; they were assessed prior to surgery, and 1, 2, 3 and 6 months post-operatively (T0, T1, T2, T3 and T6). There were no differences in osteoarthritis progression in Groups A and C at any time. Osteoarthritis changes from T0 to T6 were statistically significant in Group B. The OA changes in the anatomic locations were investigated. The most common anatomic sites for OA changes were the patella apex, the proximal and distal trochlear ridges, and the caudal aspect of the tibial plateau assessed before surgery. After surgery, the score increased in the first three locations in 10, 9 and 11 joints, respectively; instead, the progression of osteoarthritis in the caudal aspect of the tibial plateau occurred in 23 out of 38 stifle joints. The results indicated that the TTA procedure could be effective in slowing down the OA progression when carried out in the absence of or in the early stages of disease. Therefore, an early intervention may be suggested in clinical practice to obtain minimal or no progression 6 months postoperatively.

Surgical Treatments for Canine Anterior Cruciate Ligament Rupture: Assessing Functional Recovery Through Multibody Comparative Analysis

Anterior cruciate ligament (ACL) deficiency can result in serious degenerative stifle injuries. Although tibial plateau leveling osteotomy (TPLO) is a common method for the surgical treatment of ACL deficiency, alternative osteotomies, such as a leveling osteotomy based on the center of rotation of angulation (CBLO) are described in the literature. However, whether a CBLO could represent a viable alternative to a TPLO remains to be established. The aim of this study is to compare TPLO and CBLO effectiveness in treating ACL rupture. First, a computational multibody model of a physiological stifle was created using three-dimensional surfaces of a medium-sized canine femur, tibia, fibula and patella. Articular contacts were modeled by means of a formulation describing the contact force as function of the interpenetration between surfaces. Moreover, ligaments were represented by vector forces connecting origin and insertion points. The lengths of the ligaments at rest were optimized simulating the drawer test. The ACL-deficient model was obtained by deactivating the ACL related forces in the optimized physiological one. Then, TPLO and CBLO treatments were virtually performed on the pathological stifle. Finally, the drawer test and a weight-bearing squat movement were performed to compare the treatments effectiveness in terms of tibial anteroposterior translation, patellar ligament force, intra-articular compressive force and quadriceps force. Results from drawer test simulations showed that ACL-deficiency causes an increase of the anterior tibial translation by up to 5.2 mm, while no remarkable differences between CBLO and TPLO were recorded. Overall, squat simulations have demonstrated that both treatments lead to an increase of all considered forces compared to the physiological model. Specifically, CBLO and TPLO produce an increase in compressive forces of 54% and 37%, respectively, at 90° flexion. However, TPLO produces higher compressive forces (up to 16%) with respect to CBLO for wider flexion angles ranging from 135° to 117°. Conversely, TPLO generates lower forces in patellar ligament and quadriceps muscle, compared to CBLO. In light of the higher intra-articular compressive force over the physiological walking range of flexion, which was observed to result from TPLO in the current study, the use of this technique should be carefully considered.

Evaluation of recovery of limb function by use of force plate gait analysis after tibial plateau leveling osteotomy for management of dogs with unilateral cranial cruciate ligament rupture

OBJECTIVE

To evaluate recovery of limb function by use of gait force analysis after tibial plateau leveling osteotomy (TPLO) in dogs with unilateral cranial cruciate ligament (CrCL) rupture.

ANIMALS

19 dogs with unilateral CrCL rupture treated with TPLO.

PROCEDURES

Force plate gait analysis was performed before and 1, 2, 4, and 7 months after TPLO. Ground reaction forces (GRFs; which comprised peak vertical force [PVF], vertical impulse [VI], peak braking force, braking impulse, peak propulsion force [PPF], and propulsion impulse), time to switching from braking to propulsion, and vector magnitude at PVF in the forelimbs and hind limbs were evaluated.

RESULTS

GRFs in the affected hind limb were significantly lower than in the contralateral hind limb before TPLO. These variables, except for PPF, were not significantly different 7 months after TPLO. Time to the switching point in the affected hind limb was significantly less from before to 2 months after TPLO. Vector magnitude at PVF had a similar pattern as PVF and VI during the recovery process. The PVF in the ipsilateral forelimb was significantly higher than in the contralateral forelimb before TPLO.

CONCLUSIONS AND CLINICAL RELEVANCE

A similar pattern was detected between PVF or VI and craniocaudal force during recovery of dogs that underwent TPLO. Rupture of he CrCl resulted in a decrease in GRFs in the affected hind limb as well as in the switching point and PVF of limbs. However, weight distribution for the craniocaudal force was normalized before PVF or VI. Vector magnitude at PVF might be effectively evaluated by combining vertical force and craniocaudal force.

Cranial cruciate ligament structure in relation to the tibial plateau slope and intercondylar notch width in dogs

Cranial cruciate ligament (CCL) rupture is one of the most common orthopedic conditions in dogs. The pathogenesis of CCL rupture is not fully described and remains to be elucidated fully. Several hypotheses have been proposed to explain the etiology of these changes. The objective of this study was to investigate structural changes in the CCL in relation to the tibial plateau angle (TPA) and the intercondylar notch (ICN) width in dogs. Fifty-five skeletally mature dogs were included in this study. ICN width and TPA measurements were obtained from intact CCL stifles. Samples of the CCL, caudal cruciate ligament (CaCL), and femoral head ligament (FHL) were harvested and stained for routine histological and immunohistochemical analysis. Microscopic changes in the ligaments were observed and were found to correlate with the TPA and ICN width values. The degree of structural changes within the CCL was observed to correlate with an increasing TPA and a narrowing ICN width. Changes in the CCL are likely to be caused by excessive forces acting through the ligament in stifles with a high TPA. Chondroid metaplasia of the CCL is an adaptation to abnormal mechanics within the stifle joint caused by altered bone morphology.

Quantifying meniscal kinematics in dogs

The dog has been used extensively as an experimental model to study meniscal treatments such as meniscectomy, meniscal repair, transplantation, and regeneration. However, there is very little information on meniscal kinematics in the dog. This study used MR imaging to quantify in vitro meniscal kinematics in loaded dog knees in four distinct poses: extension, flexion, internal, and external rotation. A new method was used to track the meniscal poses along the convex and posteriorly tilted tibial plateau. Meniscal displacements were large, displacing 13.5 and 13.7 mm posteriorly on average for the lateral and medial menisci during flexion (p = 0.90). The medial anterior horn and lateral posterior horns were the most mobile structures, showing average translations of 15.9 and 15.1 mm, respectively. Canine menisci are highly mobile and exhibit movements that correlate closely with the relative tibiofemoral positions. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1710-1716, 2018.

The Pathobiology of the Meniscus: A Comparison Between the Human and Dog

Serious knee pain and related disability have an annual prevalence of approximately 25% on those over the age of 55 years. As curative treatments for the common knee problems are not available to date, knee pathologies typically progress and often lead to osteoarthritis (OA). While the roles that the meniscus plays in knee biomechanics are well characterized, biological mechanisms underlying meniscus pathophysiology and roles in knee pain and OA progression are not fully clear. Experimental treatments for knee disorders that are successful in animal models often produce unsatisfactory results in humans due to species differences or the inability to fully replicate disease progression in experimental animals. The use of animals with spontaneous knee pathologies, such as dogs, can significantly help addressing this issue. As microscopic and macroscopic anatomy of the canine and human menisci are similar, spontaneous meniscal pathologies in canine patients are thought to be highly relevant for translational medicine. However, it is not clear whether the biomolecular mechanisms of pain, degradation of extracellular matrix, and inflammatory responses are species dependent. The aims of this review are (1) to provide an overview of the anatomy, physiology, and pathology of the human and canine meniscus, (2) to compare the known signaling pathways involved in spontaneous meniscus pathology between both species, and (3) to assess the relevance of dogs with spontaneous meniscal pathology as a translational model. Understanding these mechanisms in human and canine meniscus can help to advance diagnostic and therapeutic strategies for painful knee disorders and improve clinical decision making.

Femorotibial kinematics in dogs with cranial cruciate ligament insufficiency: a three-dimensional in-vivo fluoroscopic analysis during walking

BACKGROUND

Cranial cruciate ligament (CrCL) insufficiency is a degenerative condition that is a common cause of pelvic limb lameness and osteoarthritis in dogs. Surgical therapies developed to treat dogs with naturally occurring CrCL insufficiency aim to address the resultant instability, but the in-vivo alterations in stifle kinematics associated with CrCL insufficiency have not been accurately defined. The objective of this study was to quantify the 3-dimensional femorotibial joint kinematics of dogs with naturally occurring cranial cruciate ligament (CrCL) insufficiency during ambulation. Eighteen client-owned dogs (20-40 kg) with natural unilateral complete CrCL rupture were included. Computed tomographic scans were used to create digital 3-dimensional models of the femur and tibia bilaterally for each dog. Lateral fluoroscopic images were obtained during treadmill walking and 3 complete gait cycles were analyzed. Stifle flexion/extension angle, craniocaudal translation, and internal/external rotation were calculated throughout the gait cycle using a previously described 3D-to-2D image registration process. Results were compared between the pre-operative CrCL-deficient and 6-month post-operative contralateral stifles (control).

RESULTS

CrCL-deficient stifles were maintained in greater flexion throughout the gait cycle. Cranial tibial subluxation was evident in CrCL-deficient stifles at all time points throughout the gait cycle [9.7 mm at mid-stance (P < 0.0001); 2.1 mm at mid-swing (P < 0.0017)], and the magnitude of cranial tibial subluxation was greater at mid-stance phase than at mid-swing phase (P < 0.0001). Greater internal tibial rotation was present in CrCL-deficient stifles during stance phase (P < 0.0022) but no difference in axial rotation was evident during swing phase.

CONCLUSIONS

Naturally occurring CrCL rupture causes profound craniocaudal translational and axial rotational instability, which is most pronounced during the stance phase of gait. Surgical stabilization techniques should aim to resolve both craniocaudal subluxation and axial rotational instability.

Second-look arthroscopic findings after CORA-based leveling osteotomy

OBJECTIVE

To describe the arthroscopic appearance of intra-articular structures mid-term (9 months) and long-term (>12 months) after CORA-based leveling osteotomy (CBLO).

STUDY DESIGN

Case series.

ANIMALS

Dogs (n = 41) with second-look arthroscopy of the stifle after CBLO for treatment of a cranial cruciate ligament (CCL) deficiency. Both stifles were re-evaluated (stifles n = 42) in 1 dog.

METHODS

Medical records of dogs that had second-look arthroscopy after CBLO were reviewed. Arthroscopic images of the femoral condyles were independently reviewed. The surgical report documented the integrity of menisci and articular cartilage of the tibial plateaus.

RESULTS

The population included 7 stifles with stable partial CCL tears, 35 stifles with complete CCL tears (n = 28), or incompetent partial CCL tears (n = 7). Median time to second look arthroscopy was 16 months (9-24 months) for stable partial tears. The CCL remained intact in 6 stifles. The Outerbridge score of the articular cartilage of the femoral condyles was as 0 (6) or 1 (1). The articular cartilage of the tibial plateaus appeared normal in all stifles. Median time to second look arthroscopy of stifles with complete tears was 12 months (range, 9-34 months). The caudal cruciate ligament was normal or mildly fibrillated. The appearance of the articular cartilage of the femoral condyles was scored as 0 or near normal (grade 1-2) in all dogs. The articular cartilage of the tibial plateaus appeared normal, except in 1 dog with grade 4 lesion.

CONCLUSION

CBLO results in minimal to no change in articular cartilage in at a median time of 14 months after surgery. Postoperative clinical lameness is often attributed to late onset meniscal pathology.

Retrospective study of 476 tibial plateau levelling osteotomy procedures

Objective: To determine the rate of subsequent ‘pivot shift’, meniscal tear and risk factors associated with complications of tibial plateau levelling osteotomy (TPLO) and to assess clinical and owner perception outcome.

Study design: Retrospective study.

Sample population: Three hundred and forty-eight dogs that had undergone TPLO surgical procedures (n = 476 stifles).

Methods: Medical records were reviewed for the retrieval of information on breed, sex, age, body weight, clinical history, radiograph findings, pre- and postoperative tibial plateau angle, limb alignment, unilateral versus bilateral disease, condition of cranial cruciate ligament (CCL) and menisci, implant material, healing time and complications. Clinical and owner-assessed questionnaire outcomes were also recorded.

Results: Forty-six (9.7%) postoperative complications were reported. Twenty (4.2%) were classified as major complications requiring an additional surgical intervention, and 26 (5.5%) as minor complications. No risk factors associated with postoperative complications were identified. Ten (2.1%) subsequent meniscal injuries in the stifles with normal unaltered menisci at time of TPLO were reported with a median postoperative time of 9.5 months. Signs of postoperative ‘pivot shift’ were reported in 15 (3.1%) stifles. All stifles with a ‘pivot shift’ had a complete CCL rupture or a debrided partial CCL rupture a medial menisectomy was identified as a risk factor for a ‘pivot shift’ (p = 0.02). Dogs with intact medial meniscus had a significantly higher activity level (p <0.0001) and a shorter time to peak function (p = 0.02) than dogs that underwent menisectomy according to an owner questionnaire.

Conclusions: Dogs with TPLO and intact meniscus seemed to have a better and faster recovery than dogs with TPLO and menisectomy based on owner questionnaires. ‘Pivot shift’ was infrequent after TPLO surgery. All dogs with a ‘pivot shift’ had a complete CCL rupture or a debrided partial CCL rupture and menisectomy was identified as a risk factor for its occurrence.

Clinical relevance: Considering the relatively low rate of subsequent meniscal injury after TPLO, systematic medial meniscal release with TPLO may be unnecessary. The ‘pivot shift’ deserved further investigation to completely understand its mechanism, to identify its anatomic components and potential consequences on the stifle joint.

The effect of tibial tuberosity advancement and meniscal release on kinematics of the cranial cruciate ligament-deficient stifle during early, middle, and late stance

Objectives: To evaluate the effect of tibial tuberosity advancement (TTA) and meniscal release on cranial-caudal and axial rotational displacement during early, middle and late stance phases in the canine cranial cruciate ligament- (CCL) deficient stifle.

Study design: In vitro biomechanical study.

Methods: Eighteen pelvic limbs were evaluated for the effects of TTA on cranial-caudal displacement and axial rotation under a load equivalent to 30% bodyweight, and under the following treatment conditions: normal (intact CCL), CCL deficient, TTA-treated (CCL deficient + TTA), and meniscal release (TTA treated + meniscal release). The limbs were evaluated in the early, middle, and late stance phases using electromagnetic tracking sensors to determine cranial tibial displacement and tibial rotation relative to the femur.

Results: Transection of the CCL resulted in significant cranial tibial displacement during early, middle, and late stance (p < 0.0001) and significant internal rotation during early (p = 0.049) and middle stance (p = 0.0006). Performance of TTA successfully eliminated cranial tibial displacement in early, middle, and late stance (p <0.0001) however, the TTA was unsuccessful in normalizing axial rotation in middle stance (p = 0.030). Meniscal release had no effect on cranial-caudal or rotational displacement when performed in conjunction with the TTA.

Clinical significance: Tibial tuberosity advancement effectively eliminates cranial tibial displacement during early, middle and late stance however, TTA failed to provide rotational stability in mid-stance.

Combining a joint health supplement with tibial plateau leveling osteotomy in dogs with cranial cruciate ligament rupture. An exploratory controlled trial

Canine cranial cruciate ligament rupture (CrCLR) is a very common pathology. Surgical stabilization is the first choice treatment, although it does not fully eliminate the increased risk of osteoarthritis. This preliminary study was carried out to explore whether a newly formulated joint health supplement would benefit metabolic, clinical and radiographic changes in dogs with CrCLR surgically treated with tibial plateau leveling osteotomy (TPLO). Besides chondroitin sulfate and glucosamine hydrochloride, the studied supplement contained anti-inflammatory and antioxidant ingredients, the main ones being N-palmitoyl-D-glucosamine (Glupamid®) and quercetin. It was thus intended to target not only chondrodegenerative components of osteoarthritis, but also post-injury inflammatory response and oxidative stress of joint tissues. Thirteen dogs underwent TPLO and were randomly allocated to treatment (n = 6) and control groups (n = 7), the former receiving the joint supplement for 90 days. Lameness and radiographic osteoarthritis changes were scored before (i.e., baseline) and at 30 and 90 days post-surgery. Synovial fluid samples were collected from injured stifles at the same time points. Levels of representative metabolites were measured by proton nuclear magnetic resonance spectroscopy in a blinded fashion. In the metabolomic analysis, special attention was paid to lactate, due to its emerging recognition as a key marker of inflammation. In the last time period (from the 30th to the 90th day), lameness improved by a factor of 2.3 compared to control dogs. No significant difference was observed in the radiographic osteoarthritis score between groups. In the first postoperative month, lactate and creatine levels significantly dropped in treated compared to control dogs. Compared to surgery alone, combining the joint supplement with TPLO resulted in a trend to a better clinical outcome in the later time interval but did not influence osteoarthritis radiographic progression. A significantly better rebalance of joint microenvironment in the early time interval (baseline - 30 days) was shown by metabolomic analysis, thus suggesting that the study supplement could limit ongoing inflammatory responses.

Systematic review of the prevalence, risk factors, diagnosis and management of meniscal injury in dogs: Part 2

OBJECTIVE

To systematically evaluate the evidence reporting the diagnosis and management of meniscal injury in dogs with cranial cruciate ligament failure.

STUDY DESIGN

Systematic literature review.

MATERIALS AND METHODS

Research questions relating to the accuracy of diagnostic techniques for meniscal injury and the effects of meniscal treatment were defined. An electronic database search of PubMed and CAB Abstracts was performed during March 2015. Data were extracted for study participants, design, intervention, outcome measures and results. Studies were evaluated using a validated instrument for assessing methodological quality and assigned a Quality Index score. A level of evidence was then assigned to each study.

RESULTS

Eighty-nine studies were identified. The median Quality Index score was 14 out of a possible 26. Twenty-seven studies were prospective case series, 31 retrospective case series, 16 animal research and 15 cadaveric studies. There were no class I or class II studies, 27 class III and 62 class IV studies.

CONCLUSIONS

Despite a large number of publications the quality of evidence was generally low. No one study or combination of studies provided high quality evidence to support one diagnostic or surgical intervention over another for meniscal injuries in dogs with cranial cruciate ligament failure.

Effect of tibial tuberosity advancement on cranial tibial subluxation in the feline cranial cruciate deficient stifle joint: An ex vivo experimental study

The effects of Tibial Tuberosity Advancement (TTA) on Cranial Tibial Subluxation (CTS) and Tibial Rotation Angle (TRA) were evaluated in a model of feline Cranial Cruciate Ligament (CrCL)-deficient stifle joint. Ten hindlimbs of adult cats were used. Quadriceps and gastrocnemius muscles were simulated using cables, turnbuckles and a spring. An axial load of 30% body weight was applied. The stifle and talocrural joint angles were adjusted to 120°. Patellar tendon angle (PTA), CTS and TRA were measured radiographically before and after CrCL section, after TTA and after additional advancement by 1 and 2mm. CrCL section resulted in a CTS of 8.1±1.5mm and a TRA of 18.4±5.7 °. After TTA, PTA was significantly decreased from 99.1±1.7° to 89.1±0.7°; CTS and TRA did not change significantly (7.8±1.0mm and 15.9±5.7° respectively). Additional advancement of the tibial tuberosity by 1mm did not significantly affect CTS and TRA. Additional advancement of the tibial tuberosity by 2mm significantly reduced the PTA to 82.9±0.9°. A significant decrease of CTS (6.9±1.3mm) and TRA (14.7±3.6°) was also observed. A lack of stabilization of the CrCL deficient stifle was observed after TTA in this model of the feline stifle. Even though the validity of the model can be questioned, simple transposition of the technique of TTA from the cat to the dog appeared hazardous.

The structural and compositional transition of the meniscal roots into the fibrocartilage of the menisci

The meniscal roots, or insertional ligaments, firmly attach the menisci to tibial plateau. These strong attachments anchor the menisci and allow for the generation of hoop stress in the tissue. The meniscal roots have a ligament-like structure that transitions into the fibrocartilagenous structure of the meniscal body. The purpose of this study was to carry out a complete analysis of the structure and tissue organization from the body of the meniscus through the transition region and into the insertional roots. Serial sections were obtained from the meniscal roots into the meniscal body in fixed juvenile bovine menisci. Sections were stained for collagen and proteoglycans (PG) using fast green and safranin-o staining protocols. Unstained sections were imaged used a backlit stereo microscope. Optical projection tomography (OPT) was employed to evaluate the three-dimensional collagen architecture of the root-meniscus transition in lapine menisci. Tie-fibres were observed in the sections of the ligaments furthest from the bovine meniscal body. Blood vessels were observed to be surrounded by these tie-fibres and a PG-rich region within the ligaments. Near the tibial insertion, the roots contained large ligament-like collagen fascicles. In sections approaching the meniscus, there was an increase in tie-fibre size and density. Small tie-fibres extended into the ligament from the epiligamentous structure in the outermost sections of the meniscal roots, while large tie-fibre bundles were apparent at the meniscus transition. The staining pattern indicates that the root may continue into the outer portion of the meniscus where it then blends with the more fibrocartilage-like inner portions of the tissue. In unstained sections it was observed that the femoral side of the epiligamentous structure surrounding the root becomes more fibrous and thickens in the inferior inner portion of the posterior medial root. This thickening changes the shape of the root to more closely resemble the meniscus wedge shape. These observations support the concept of root continuity with the outer portion of the meniscus, thereby connecting with the hoop-like structure of the peripheral meniscus. OPT identified continuous collagen organization from the root into the meniscal body in longitudinal sections. In the radial direction, the morphology of the root continues into the meniscal body consistent with the serially sectioned bovine menisci. Blood vessels were prevalent on the periphery of the root. These blood vessels then arborized to cover the anterior femoral surface of the meniscus. This is the first study of the structural transition between the insertional ligaments (roots) and the fibrocartilagenous body of the menisci. These new structural details are important to understanding the meniscal load-bearing mechanism in the knee.

Comparison of growth factor treatments on the fibrochondrogenic potential of canine fibroblast-like synoviocytes for meniscal tissue engineering

OBJECTIVE

To determine the in vitro effects of differing growth factor treatments on the fibrochondrogenic potential of fibroblast-like synoviocytes from cruciate ligament deficient femorotibial joints of dogs.

STUDY DESIGN

In vitro study.

SAMPLE POPULATION

Synoviocytes from dogs (n = 8) with naturally occurring cruciate ligament insufficiency.

METHODS

Synoviocytes were cultured in monolayer and synthesized into tensioned synoviocyte bioscaffolds (TSB) suspended in media containing TGF-β3, or FGF-2, TGF-β1, and IGF-I. The 1,9-dimethylmethylene blue (DMMB) assay and toluidine blue stain assessed glycosaminoglycan content; hydroxyproline assay, and collagen I and II immunohistochemistry assessed collagen content. Biomechanical properties were determined by materials testing/force-deformation curves.

RESULTS

All tissue cultures formed tensioned fibrous tissue-like constructs. Mean tissue cellularity and cellular viability was significantly greater in the triple growth factor-treated TSB by 0.09% and 44%, respectively. Percentage collagen content, and relative gene expression for collagen I, II, and aggrecan was not significantly different between groups. Median percentage of GAG content was significantly greater in triple growth factor-treated TSB by 1.6%. Biomechanical properties were not different in compression. Triple growth factor-treated TSB were significantly stronger in toughness, peak load to failure, and stiffness in tension.

CONCLUSIONS

TGF-β3 cultured bioscaffolds failed to outperform triple growth factor-treated TSB. Architectural extracellular matrix (ECM) organization and cellularity likely explained the differences between groups. TGF-β3 alone cannot be recommended at this time for in vitro formation of autologous fibrocartilage bioscaffolds for meniscal deficiency.

Lateral and medial tibial plateau angles in normal dogs. An osteological study

OBJECTIVES

To measure lateral and medial tibial plateau angle values in isolated canine tibiae and to compare lateral and medial tibial plateau angle values between dogs based on sex and breed.

METHODS

Tibiae of 90 dogs from 24 different breeds were used. Photographs were taken of the medial and lateral aspects of the tibiae for measurement of the medial and lateral tibial plateau angles. Additionally, the medial tibial plateau angle was measured from radiographs of the tibiae. Two-way analysis of variance was used to test the effects of side, sex and breed on the medial and lateral tibial plateau angles as measured from photographs as well as the medial tibial plateal angles as measured from radiographs. The photographic and radiographic medial tibial plateau angles were compared by paired t-test, whereas the medial and lateral photographic tibial plateau angles were compared by t-test.

RESULTS

When all dogs were included in the analysis, the difference between the mean medial tibial plateau angle (24.0 ± 3.19°) and the mean lateral tibial plateau angle (25.5 ± 3.84°) as measured from photographs was significant (p <0.05). The difference in the photographic medial tibial plateau angle between male and female dogs was significant (p <0.05), whereas the difference in the photographic lateral tibial plateau angle between sexes was not significant. There was a significant difference between the medial and lateral tibial plateau angles as measured from photographs in male dogs (p <0.05) but not in female dogs. Breed comparisons also showed significant differences for the photographic lateral tibial plateau angle (p <0.05).

CLINICAL SIGNIFICANCE

The axial rotation of the femoral condyles on the tibial plateau is probably affected by the discrepancy between the medial and lateral tibial plateau angles, and this difference in certain breeds might influence the prevalence of cranial cruciate ligament disease.

Comparison of gait and pathology outcomes of three meniscal procedures for induction of knee osteoarthritis in sheep

OBJECTIVE(S)

Meniscectomy (MX) of sheep induces a well-established animal model of human osteoarthritis (OA). This study compared the clinical (lameness) and pathological outcomes of unilateral, complete medial MX vs two less traumatic and more easily performed meniscal destabilisation procedures.

METHODS

Four-year old wethers (n = 6/group) underwent sham operation, cranial pole release (CPR), mid-body transection (MBT) or total MX of the medial meniscus. Joints were assessed for gross pathology (cartilage erosion and osteophytes), histomorphometry, two histopathology scoring methods (modified Mankin-type and Pritzker score), and immunohistology for ADAMTS- and MMP-cleaved neoepitopes, at 12 weeks post-op. Ground reaction forces (GRFs) were determined by force plate in a subset (n = 4/group) at baseline, 2.5, 8, and 12 weeks post-op.

RESULTS

Gross pathology scores of operated groups differed significantly from sham animals (P < 0.05) but not from each other, though qualitative differences were noted: CPR sheep developed more cranial and focal lesions, while MBT and MX joints showed more widespread lesions and osteophyte formation. Similarly, histopathology scores were significantly elevated vs sham but did not differ between operated groups at P < 0.05, except for a trend for lower tibial cartilage histopathology in MBT consistent with the immunohistologic pattern of reduced aggrecanase-cleavage neoepitope in that model. CPR sheep developed less femoral subchondral sclerosis, suggesting some residual biomechanical effect from the destabilised but intact meniscus. Few significant differences were noted between operated groups in force plate analyses, though gait abnormalities appeared to be least in CPR sheep, and most persistent (>12 weeks) in MBT animals.

CONCLUSION

The well-validated ovine MX model and the simpler meniscal destabilisation procedures resulted in broadly similar joint pathology and lameness. Meniscal CPR or MBT, as easier and more clinically relevant procedures, may represent preferred models for the induction of OA and evaluation of potential disease-modifying therapies.

Radiographic landmarks for measurement of cranial tibial subluxation in the canine cruciate ligament deficient stifle

OBJECTIVES

The primary objective was to develop a repeatable radiographic technique for assessment of cranial tibial subluxation (CTS) and test the intra-observer and inter-observer repeatability of the chosen landmarks. A secondary objective was to determine the effects of digital radiographic magnification on CTS measurement repeatability.

METHODS

Twenty-three normal canine pelvic limbs were used to determine the magnitude of CTS before and after transection of the cranial cruciate ligament. Mediolateral radiographs were taken with and without fiduciary markers in place. Three investigators measured the CTS using radiographically visible anatomic landmarks at two different magnifications. The total observed variabilities were assessed by inter-observer and intra-observer differences. Paired t-tests were used to determine the effect of magnification and marker presence on CTS measures.

RESULTS

Measurement of the CTS from the caudal margin of the intercondylar fossa on the femur to the intercondylar eminence was the most repeatable. Poor correlation between the anatomic landmarks and the fiduciary bone markers was observed. We found no effect of magnification or presence or absence of bone markers on measurement of CTS.

CLINICAL SIGNIFICANCE

Cranial tibial subluxation can be detected with the most repeatability by measuring between the caudal margin of the intercondylar fossa and the intercondylar eminence. Magnification of the digitized radiographic image had minimal effect on repeatability. This technique can be used for in vivo analysis of the canine cruciate ligament deficient stifle joint.

Effect of tibial plateau leveling osteotomy on femorotibial subluxation: in vivo analysis during standing

OBJECTIVE

To assess the effect of tibial plateau leveling osteotomy (TPLO) on femorotibial subluxation during standing in dogs with cranial cruciate ligament (CrCL) insufficiency.

STUDY DESIGN

Prospective clinical study.

ANIMALS

Fifteen dogs weighing 20-45 kg with unilateral complete CrCL insufficiency.

METHODS

Force-platform analysis, and lateral weight-bearing radiographs of the affected stifle were acquired preoperatively, 1, 3, and 6 months postoperatively. The distance between the origin and insertion of the CrCL (CrCL(d) ) was measured on each radiograph and compared between time points using ANOVA. Lateral radiographs of the non-weight-bearing affected stifle and weight-bearing contralateral normal stifle were acquired preoperatively, and CrCL(d) was compared with a paired t-test. Dogs were grouped according to medial meniscal status (intact or hemimeniscectomy) and CrCL(d) was compared within each group using ANOVA.

RESULTS

No difference was observed in CrCL(d) between the non-weight-bearing affected stifle and the contralateral stifle (P = .994). That is, femorotibial joint alignment in the affected stifle when non-weight-bearing was considered normal. Preoperatively in the affected stifle, CrCL(d) during weight-bearing was 6.3 ± 2.4 mm longer than normal (P < .001). Postoperative weight-bearing CrCL(d) in dogs with intact menisci at all time points was not statistically different from normal; CrCL(d) at 1 (P = .014) and 6 months (P = .005) postoperatively was longer than normal in dogs with hemimeniscectomy.

CONCLUSIONS

TPLO does not consistently resolve femorotibial subluxation during standing in dogs with CrCL insufficiency. The medial meniscus appears to be an important contributor to stability in stifles treated by TPLO.

Incidence of medial meniscal tears after arthroscopic assisted tibial plateau leveling osteotomy

OBJECTIVE

To determine the incidence of medial meniscal tears in dogs with naturally occurring cranial cruciate ligament (CCL) disease treated with arthroscopy and tibial plateau leveling osteotomy (TPLO).

STUDY DESIGN

Retrospective case series.

SAMPLE POPULATION

Canine Stifles (n = 357) with naturally occurring CCL disease.

METHODS

Medical records (November 2006-November 2009) were reviewed for all dogs with CCL disease treated with arthroscopic CCL debridement, meniscal probing, and TPLO. We investigated the significance of the preoperative variables; age, weight, tibial plateau angle (TPA), sex, and the preoperative condition of the CCL on the prevalence of concurrent meniscal tears (CMT) and incidence of late onset meniscal tears (LMT).

RESULTS

Prevalence of CMT and incidence of LMT was 32.2% and 5.6%, respectively. A significant difference between age of dogs with and without CMT was identified. There was a significantly lower prevalence of CMT and incidence of LMT in dogs that had a partial CCL tear compared with those that had a complete CCL tear. All dogs with LMT treated by partial meniscectomy (PMM) returned to peak postoperative limb function after (PMM) based on client-assessed outcomes.

CONCLUSIONS

This study demonstrates the importance of LMT as a complication, the importance of comprehensive meniscal assessment, and may add to the evidence against routinely performing meniscal release in TPLO. The preoperative condition of the CCL should be considered before operating on grossly normal menisci.

Geometry of the femoral condyles in dogs

The stifle joint is one of the most important joints in dogs from the orthopaedic point of view. The aim of this study was to document the morphometric values of femoral condyles, given the close relationship between the shape and function of an anatomic structure. The left femora of 16 mid-sized dogs were used, and diameter and nine radii as well as cranial and caudal bow lengths from each condyle were measured. The photographs were taken of the distal femora from both sides. All measurements were obtained from these images by using software. Additionally, the rotation angle was calculated from the intercondylar distance and the difference between lateral and medial bow lengths. In addition to the rotation angle, the difference of diameter and nine radii between the lateral and medial condyles was determined. All radii except getting at 90° were significantly different between the medial and lateral condyles. The greatest values were determined in the caudal part of the medial condyle. This results the smaller contact area and a greater pressure on the underlying surface, and therefore the meniscus and articular cartilage of the caudal part of the medial side suggests the possibility of a risk of injury as the stifle joint flexes. The mean rotational angle of the femur was also calculated to be 2.18° laterally and 1.02° medially in the caudal and cranial parts of condyles, respectively. The result of this study showed that the lateral and medial condyles had different shapes in canine femur.

Subchondral bone changes in three different canine models of osteoarthritis

OBJECTIVE

To test the hypothesis that changes in subchondral bone are significantly different among three canine models of osteoarthritis (OA).

DESIGN

In 21 purpose-bred mongrel dogs, OA was induced in one knee joint via either anterior cruciate ligament transection (ACLt; n = 5), medial femoral condylar groove creation (GR; n = 6), or medial meniscal release (MR; n = 5). Five dogs that had sham surgery (SH; n = 5) in one knee joint served as controls. Lameness scoring was performed every 4 weeks. Twelve weeks after surgery, the knee joints were examined by histology and histomorphometry.

RESULTS

Articular cartilage pathology as determined by Mankin scores was significantly severe in all three OA models compared to SH controls in the medial tibia (P < 0.001 to P = 0.026). ACLt had significantly thinner subchondral plate thickness (Sp.Th) in both the medial and lateral tibias while MR had significantly thicker Sp.Th in the medial tibia compared to SH controls (P < 0.001 to P = 0.011). Trabecular bone volume (BV/TV) and trabecular bone thickness (Tb.Th) for ACLt were significantly less than SH controls in the tibias (P < 0.001 to P = 0.011). Tibial Sp.Th, BV/TV, and Tb.Th were all moderately to strongly correlated with lameness scores obtained throughout the study period (r = -0.436 to r = -0.738, P < 0.001 to P = 0.047) while Mankin scores showed moderate to strong correlations with Sp.Th in each OA model (r = 0.465 to r = 0.816, P < 0.001 to P = 0.033).

CONCLUSIONS

Changes in Sp.Th are associated with articular cartilage damage while tibial Sp.Th and BV/TV and Tb.Th appear to be all influenced by joint loading alterations.

Cranial cruciate ligament disease in dogs: biology versus biomechanics

The stifle joint of dogs is an organ comprised of multiple tissue types that must work in concert to maintain joint health and function. Cruciate disease in dogs is caused by a spectrum of causal and risk factors that result in a final common pathway of abnormal biomechanics and abnormal biology causing osteoarthritis, or organ failure, of the stifle and the clinical signs of lameness, pain, and limb dysfunction. It is vital to understand the components of the biologic and biomechanical pathologies to improve our understanding of cruciate disease in dogs so that we can improve preventative, diagnostic, and therapeutic strategies for our canine patients.

Comparison of short- and long-term function and radiographic osteoarthrosis in dogs after postoperative physical rehabilitation and tibial plateau leveling osteotomy or lateral fabellar suture stabilization

OBJECTIVES

To compare short- and long-term functional and radiographic outcome of cranial cruciate ligament (CrCL) injury in dogs treated with postoperative physical rehabilitation and either tibial plateau leveling osteotomy (TPLO) or lateral fabellar suture stabilization (LFS).

STUDY DESIGN

Prospective observational clinical study.

ANIMALS

Medium to large breed dogs with naturally occurring CrCL injury (n=65).

METHODS

Dogs with CrCL injury were treated with either TPLO or LFS and with identical physical rehabilitation regimes postoperatively. Limb peak vertical force (PVF) was measured preoperatively and at 3, 5, and 7 weeks, and 6 months and 24 months postoperatively. Stifles were radiographically assessed for osteoarthrosis (OA) preoperatively and 24 months postoperatively.

RESULTS

Thirty-five dogs had LFS and 30 dogs had TPLO. Radiographic OA scores were significantly increased at 24 months compared with preoperative scores in all dogs. Radiographic OA scores preoperatively and at 24 months were not significantly different between treatment groups. PVF was significantly increased from preoperative to 24 months among both treatment groups but not significantly different between treatment groups preoperatively or at 3, 5, 7 weeks, 6, or 24 months.

CONCLUSION

No significant difference in outcome as determined by ground reaction forces or radiographic OA scores were found between dogs with CrCL injury treated with LFS or TPLO.

CLINICAL RELEVANCE

LFS and TPLO remain good options for stabilizing stifles with CrCL injury with all dogs showing significant functional improvement. This study does not support the superiority of either surgical technique.

Potential iatrogenic medial meniscal damage during tibial plateau leveling osteotomy

OBJECTIVE

To evaluate potential iatrogenic medial meniscal (MM) damage during tibial plateau leveling osteotomy (TPLO) and to establish a safe zone (SZ) for hypodermic needle (HN) identification of the medial aspect of the stifle joint.

STUDY DESIGN

Prospective cohort.

ANIMALS

Cadaveric canine stifles (n=40).

METHODS

HN (20 or 25 G) were inserted through the medial collateral ligament (MCL) of the femorotibial joint and through the SZ insertion points. The medial meniscus was inspected for iatrogenic damage. Statistical comparison of MM damage caused by different needle sizes and insertion sites was performed using Fisher's exact test with significance at P< .05.

RESULTS

Twenty-gauge group: 65% of stifles had minor MM damage with MCL insertion compared with 35% of stifles with SZ insertion (P=.0049). Severe MM damage occurred in 25% of stifles with MCL insertion compared with 0% of stifles with SZ insertion (P=.0014). Twenty-five-gauge group: 85% of stifles had minor MM damage with MCL insertion compared with 30% after SZ insertion (P=.0011); however, no severe MM injury was noted.

CONCLUSIONS

HN insertion though the MCL can produce iatrogenic damage to the MM. Use of a 25 G HN and SZ site for insertion reduced the frequency and severity of MM damage.

CLINICAL RELEVANCE

HN insertion into the medial aspect of the femorotibial joint during TPLO can cause gross iatrogenic MM damage, which may contribute to the incidence and misdiagnosis of latent MM injuries after TPLO.

Meniscal release in cruciate ligament intact stifles causes lameness and medial compartment cartilage pathology in dogs 12 weeks postoperatively

OBJECTIVE

To evaluate after 12 weeks the effects of caudal medial meniscal release (MR) in the cranial cruciate ligament-intact canine stifle.

STUDY DESIGN

Blinded, prospective in vivo study.

ANIMALS

Purpose-bred hound dogs (n=10).

METHODS

Either MR (n=5) or a sham (SH) surgery (n=5) was performed via arthroscopy. Orthopedic examination and subjective lameness evaluation were performed in each dog preoperatively and at 4, 8, and 12 weeks after surgery. Twelve weeks postoperatively, ultrasonographic, radiographic, and arthroscopic examinations were performed on the operated stifles. Gross pathology of the articular cartilage, cruciate ligaments, and menisci was assessed. India ink staining of the femoral and tibial articular surfaces was performed to determine the percent area of articular cartilage damage.

RESULTS

At 8 and 12 weeks after surgery, MR dogs were lamer than SH dogs. At 12 weeks, the degree of radiographic OA was significantly higher in MR stifles than in SH stifles. Gross and sonographic meniscal pathology was more severe in MR stifles compared with SH stifles. MR stifles had significantly more severe articular cartilage pathology compared with SH stifles 12 weeks after surgery; pathology was most severe in the medial compartment.

CONCLUSIONS

MR alone is associated with articular cartilage loss, further meniscal pathology, degenerative joint disease, and lameness.

CLINICAL RELEVANCE

Subsequent osteoarthritis and dysfunction of the stifle joint should be considered when making clinical decisions regarding MR in dogs.

Tibial osteotomies for cranial cruciate ligament insufficiency in dogs

OBJECTIVE

To review the biomechanical considerations, experimental investigations, and clinical data pertaining to tibial osteotomy procedures for treatment of cranial cruciate ligament (CrCL) insufficiency in dogs.

STUDY DESIGN

Literature review.

METHODS

Literature search through Pub Med, Veterinary Information Network, Commonwealth Agricultural Bureau Abstracts, and conference proceedings abstracts (November 1977 to March 2007).

RESULTS

Reported tibial osteotomy procedures attempt to eliminate sagittal instability (cranial tibial thrust) in CrCL-deficient stifles by altering the conformation of the proximal tibia. Functional stability can be achieved by decreasing the tibial plateau slope (cranial tibial closing wedge osteotomy [CTWO], tibial plateau leveling osteotomy [TPLO], combined TPLO and CTWO, proximal intraarticular osteotomy, chevron wedge osteotomy), altering the alignment of the patellar tendon (tibial tuberosity advancement), or both (triple tibial osteotomy). Clinical reports assessing the efficacy of these procedures frequently use subjective outcome measures, and the periods of follow-up evaluation are highly variable. Satisfactory results have been reported in most (>75%) dogs irrespective of the type of tibial osteotomy procedure.

CONCLUSIONS

Currently available data does not allow accurate comparisons between different tibial osteotomy procedures, or with traditional methods of stabilizing the CrCL-deficient stifle. Carefully designed long-term clinical studies and further biomechanical analyses are required to determine the optimal osteotomy technique, and whether these procedures are superior to other stabilization methods.

CLINICAL RELEVANCE

Limb function in dogs with CrCL insufficiency can be improved using the currently described tibial osteotomy techniques.

Tibial Tuberosity Advancement for Stabilization of the Canine Cranial Cruciate Ligament-Deficient Stifle Joint: Surgical Technique, Early Results, and Complications in 101 Dogs

OBJECTIVE

To describe the surgical technique, early results and complications of tibial tuberosity advancement (TTA) for treatment for cranial cruciate ligament (CrCL)-deficient stifle joints in dogs.

STUDY DESIGN

Retrospective clinical study.

ANIMALS

Dogs (n=101) with CrCL-deficient stifles (114).

METHODS

Medical records of 101 dogs that had TTA were reviewed. Complications were recorded and separated into either major or minor complications based on the need for additional surgery. In-hospital re-evaluation of limb function and time to radiographic healing were reviewed. Further follow-up was obtained by telephone interview of owners.

RESULTS

Complications occurred in 31.5% of the dogs (12.3% major, 19.3% minor). Major complications included subsequent meniscal tear, tibial fracture, implant failure, infection, lick granuloma, incisional trauma, and medial patellar luxation; all major complications were treated with successful outcomes. All but 2 minor complications resolved. The mean time to documented radiographic healing was 11.3 weeks. Final in-hospital re-evaluation of limb function (mean, 13.5 weeks), was recorded for 93 dogs with lameness categorized as none (74.5%), mild (23.5%), moderate (2%), and severe (1%). All but 2 owners interviewed were satisfied with outcome and 83.1% reported a marked improvement or a return to pre-injury status.

CONCLUSIONS

TTA is a procedure comparable with alternate methods of CrCL repair with expected good to excellent functional outcome.

CLINICAL RELEVANCE

TTA procedure can be successfully used to obtain the dynamic stability of a CrCL-deficient stifle joint in dogs.

The role of the high tibial osteotomy in the unstable knee

High tibial osteotomy is an accepted treatment option for knee arthrosis in association with coronal malalignment. However, the effect of this procedure on the sagittal balance of the knee has until recently been largely ignored. Basic science research over the past several years and some small clinical series have introduced a "novel" concept whereby the sagittal balance of a ligament deficient knee can be restored to some degree by altering the posterior tibial slope. This review summarizes the available evidence supporting the role of selective high tibial osteotomy in the treatment of both the acute and chronic ligament deficient knee.