Management of concurrent patellar luxation and cranial cruciate ligament rupture using modified tibial plateau levelling

Assessing the Effectiveness of Modified Tibial Plateau Leveling Osteotomy Plates for Treating Cranial Cruciate Ligament Rupture and Medial Patellar Luxation in Small-Breed Dogs

In small-breed dogs with concurrent cranial cruciate ligament rupture (CCLR) and medial patellar luxation (MPL), correcting both disorders is are essential for restoring normal gait. However, the previously described surgical treatment, using two osteotomy technique, poses a high risk of fracture and instability. Addressing CCLR and MPL with a single osteotomy and implant was considered superior to the conventional method. Therefore, a pre-contoured modified tibial plateau leveling osteotomy (PCM-TPLO) plate facilitating medial shifting of the proximal tibia was developed. We compared postoperative alignment and strength between this novel plate group and a conventional tibial plateau leveling osteotomy (TPLO) plate group using eight small-breed dog cadavers each. Additionally, we investigated the potential of the novel plate as an alternative to tibial tuberosity transposition. Postoperative alignment and strength were assessed through radiographs and mechanical testing. Measurements including tibial plateau angle, mechanical medial proximal tibial angle, and number of screws within the joint were also analyzed. There were no significant differences in all measured parameters. For the novel plate, the medial displacement ratio of the proximal tibia was confirmed to be approximately 30%, and the result was thought to be appropriate. These findings suggest that the PCM-TPLO plate could be a promising alternative for treating concurrent CCLR and MPL in small-breed dogs.

Short-term outcomes of cranial cruciate ligament rupture treated surgically with tibial plateau leveling osteotomy or non-surgically in small-breed dogs weighing less than10 kg

Cranial cruciate ligament rupture (CCLR) is a common cause of stifle joint pain in dogs. This study assessed the short-term outcomes in the management of CCLR, with or without concurrent medial patellar luxation (MPL), in small-breed dogs, comparing surgical intervention using tibial plateau leveling osteotomy (TPLO) with non-surgical approaches. Dogs weighing less than 10 kg and suffering from CCLR were divided into two groups: surgical and non-surgical (nine stifles per group). Both groups followed the same rehabilitation protocol. Measurements were taken on days 0, 14, 28, 42, 56, 70, and 84. These measurements included the mean difference in orthopedic assessment score (diffOAS) and thigh muscle circumference (TMC) assessed by veterinarians, as well as the Canine Brief Pain Inventory score (CBPI) evaluated by the owners. Six stifles had concurrent MPL in the surgical group and five in the non-surgical group. No significant differences were observed in diffOAS (P=0.685), TMC (P=0.557), CBPI pain severity score (P=0.062), and CBPI pain interference score (P=0.29) between the two groups. However, both groups showed a significant decrease (P<0.05) in diffOAS and CBPI. The TMC remained relatively stable in the non-surgical group (P>0.05), but it significantly increased in the surgical group (P<0.05). Both groups demonstrated improved clinical outcomes in the short term, with no significant differences. However, cautious consideration should be given to a conservative treatment in small-breed dogs, particularly when considering the exclusive improvement observed in TMC within the TPLO group.

Complications and Long-Term Outcomes after Combined Tibial Plateau Leveling Osteotomy and Tibial Tuberosity Transposition for Treatment of Concurrent Cranial Cruciate Ligament Rupture and Grade III or IV Medial Patellar Luxation

OBJECTIVES

 This study aims to report complications and long-term outcomes of combined tibial plateau leveling osteotomy and tibial tuberosity transposition (TPLO-TTT) for treatment of concurrent cranial cruciate ligament rupture and medial patellar luxation (MPL).

STUDY DESIGN

 This is a retrospective study. Dogs that underwent TPLO-TTT for treatment of combined cranial cruciate ligament rupture and grade III or IV MPL were included. Signalment, fixation method, and complications were recorded. Long-term outcome assessment (minimum 1 year postoperatively) was performed through clinical and radiographic reexamination at the authors' institution.

RESULTS

 Twenty-four stifles (22 dogs) were included. Twenty-one stifles had a grade III MPL, and 3 stifles had grade IV MPL. Four major complications consisting of surgical site infection (n = 3) and recurrent grade II MPL (n = 1) were observed. Dogs with surgical site infections were successfully treated with implant removal and oral antibiotics. No additional surgery was performed for the patient with recurrent MPL as no signs of lameness were observed. Minor complications occurred in five cases. At long-term evaluation (median: 27 months; range: 12-67 months), 21/22 dogs were clinically sound and 23/24 stifles had a complete resolution of MPL.

CONCLUSION

 TPLO-TTT can be considered as an effective surgical option to treat patients with concurrent cranial cruciate ligament rupture and MPL with a relatively low major complication rate. Owners should be warned of the potential need for implant removal.

Effect of Plate Type on Tibial Plateau Levelling and Medialization Osteotomy for Treatment of Cranial Cruciate Ligament Rupture and Concomitant Medial Patellar Luxation in Small Breed Dogs: An In Vitro Study

OBJECTIVE

 The main aim of this study was to determine the effective magnitude of proximal tibial segment medialization achievable during tibial plateau levelling and medialization osteotomy (TPLO-M) with Fixin 1.9-2.5 mm pre-contoured T plates with three different offsets.

METHODS

 In this in vitro study, 36 tibia bone models reconstructed using stereolithography from hindlimb CT scans of a 5 kg dog and a 10 kg dog without orthopaedic disease were used. TPLO-M was performed using plates with three different offsets (2, 4 and 6 mm). Post-osteotomy radiographic and bone models measurements were performed.

RESULTS

 Regardless of patient weight, the +4 mm offset plates provided a translation of 2.93mm (± 0.51) while the +6 mm offset plates provided a translation of 5.03mm (± 0.47). In the 5kg dog bone model group limited bone contact at the osteotomy site was documented when using the +6mm offset plate.

CONCLUSION

 The +4mm and +6mm offset Fixin plates may be considered for TPLO-M in dogs weighing between 5 and 10 kg. The +6mm offset plate should be used cautiously in dogs weighing less than 10 kg since this plate may result in insufficient postoperative bone apposition at the osteotomy site.

Inter- and Intra-Observer Variations in Radiographic Evaluation of Pelvic Limbs in Yorkshire Terriers with Cranial Cruciate Ligament Rupture and Patellar Luxation

The main aims of the study were to describe bone alignment differences in Yorkshire Terriers (YT) with cranial cruciate ligament rupture (CCLR), patellar luxation (PL), or with a combination of both (CCLR + PL); to verify the theory of increased strain on cranial cruciate ligament (CrCL) due to PL as a predisposing factor; and to evaluate intra- and inter-observer variability of the protocols developed for measurement of femoral and tibial alignment in Yorkshire Terriers. Fifty-five hindlimbs of YT were divided into four groups: Control, CCLR, PL, and CCLR + PL. Thirty parameters were radiographically evaluated including hip joint, femoral, tibial, and intercondylar fossa (ICF) parameters. Three observers evaluated all parameters on two separate occasions with a twelve-week interval between measurements. Significant differences in conjunction with CCLR and PL theories between groups were noticed in: Norberg angle (NA), quadriceps angle (Qa), anatomic lateral distal femoral angle (aLDFA), femoral varus (FVA), mechanical cranial proximal tibial angle (mCrPTA), mechanical caudal proximal tibial angle (mCdPTA), tibial plateau angle (TPA), distal tibial axis/proximal tibial axis angle (DPA). Some interesting findings are the similarity of values between Control and CCLR vs. CCLR + PL and PL groups in Na, Qa, aLDFA; between CCLR + PL and PL in FVA and a significantly lower age of dogs in CCLR + PL compared to CCLR group. Based on our results, we can conclude that YT with different clinical findings have differing bone morphology. Moreover, these findings may support PL as a predisposing factor for CCLR in small breeds. Measurements in which excellent inter- observer agreement was achieved may be used for surgical planning or for further discussions.

Combined center of rotation of angulation-based leveling osteotomy and tibial tuberosity transposition: An ex vivo mechanical study

OBJECTIVE

To describe the technique of combined center of rotation of angulation (CORA)-based leveling osteotomy (CBLO) with tibial tuberosity transposition (TTT) and to compare the load to failure between CBLO combined with TTT and CBLO or TTT alone.

STUDY DESIGN

Ex vivo study.

SAMPLE POPULATION

Twelve pairs of cadaveric pelvic limbs.

METHODS

Six pairs of cadaveric tibia were tested in each group (CBLO-TTT versus CBLO) and (CBLO-TTT versus TTT) with each limb randomly assigned to a treatment group. Construct stability was determined by applying a tensile force to each patellar tendon until failure occurred. Load at failure and mode of failure were recorded for each specimen.

RESULTS

No difference in mean load to failure was identified between CBLO-TTT (897 N) and CBLO alone (943 N) (P = .81). There was also no difference in the mean load to failure between the CBLO-TTT (928 N) and TTT alone (1046 N) (P = .12).

CONCLUSION

Performing a TTT in combination with a CBLO does not weaken the construct failure to load when compared with each procedure performed alone.

CLINICAL SIGNIFICANCE

A combined CBLO and TTT could be considered a viable option for concurrent management of a cranial cruciate ligament deficient stifle and medial patella luxation.

Patellar luxation and concomitant cranial cruciate ligament rupture in dogs - A review

A patellar luxation and concomitant cranial cruciate ligament rupture is a common pathology in dogs. Diagnosis is based on clinical evidence of a patellar luxation and stifle joint instability. However, diagnostic imaging is required to assess the number of skeletal deformities and signs of instability. Surgical options include both soft tissue and osseous techniques, although, in most cases, a combination of multiple procedures is necessary to correct the patellar luxation and restore the stifle joint stability. Complication rates are generally low, but can include reluxation and implant-associated complications. This article describes the patellar luxation and cranial cruciate ligament rupture signs in dogs, including the clinical presentation and diagnosis, and discusses current treatment options.

Tibial tuberosity transposition advancement for treatment of concomitant cranial cruciate ligament rupture and medial patellar luxation in four feline stifles

Case series summary

Three cats (four stifles) were diagnosed with varying grades of medial patellar luxation and stifle instability in cranial tibial thrust. Radiographs showed periarticular osteophytosis, intra-articular mineralization and opacification encroachment of the infrapatellar fat pad. Stifle exploration revealed either partial (n = 2) or complete (n = 2) cranial cruciate ligament tear and medial meniscal injury in all cases. Medial meniscectomy, partial parasagittal patellectomy, femoral trochleoplasty and tibial tuberosity transposition advancement using a 6 mm cage, two-fork plate and 4 mm spacer were performed in four stifles. Screws (2.0 mm) and washers were used in the cranial cage ears rather than conventional 2.4 mm screws. By the 2-week recheck, lameness was minimal and stifles were stable. Radiographic follow-up at 8 weeks showed appropriate progression of osseous union in all cases. One cat experienced a major complication, suffering tibial fracture following a lapse in exercise restriction, and revision surgery was performed successfully with subsequent osseus union of the osteotomy site. At the mid-term follow-up, all cats had a return to previous level of function, as assessed by both owner questionnaire and clinical evaluation.

Relevance and novel information

Tibial tuberosity transposition and advancement has been shown to be successful in dogs for the treatment of concomitant medial patellar luxation and cranial cruciate ligament rupture. To date, there have been no reports of tibial tuberosity transposition and advancement in cats. A benefit of this approach is concomitant alignment of the extensor mechanism and neutralization of the femorotibial shear force. Our case series describes successful use of tibial tuberosity transposition advancement in cats.

Modified tibial plateau levelling osteotomy to treat lateral patellar luxation and cranial cruciate ligament deficiency in a dog

The use of modified tibial plateau leveling osteotomy adapted for correction of the lateral patellar dislocation was effective, allowing simultaneous treatment of lateral patellar luxation and cranial cruciate ligament deficiency.

Risk factors for short-term postoperative complications in the 8 weeks after tibial plateau leveling osteotomy in dogs weighing less than 15 kilograms: A retrospective study

The purpose of this retrospective study was to evaluate the risk factors for short-term postoperative complications in the 8 weeks after unilateral tibial plateau leveling osteotomy (TPLO) for cranial cruciate ligament rupture in small dogs weighing less than 15 kg. Medical records were retrospectively reviewed for 90 dogs weighing <15 kg that underwent medial parapatellar arthrotomy with inspection of the meniscus and TPLO performed by the same surgeon between January 2012 and December 2017. The overall complication rate was 4.44% (4/90 dogs). There were four cases of partial incisional dehiscence, none of which required surgical revision. Complications were significantly more likely in dogs that had undergone placement of a 2.4-mm TPLO plate. Overall, the complication rate was less than that in previous studies of dogs weighing > 15kg. In this study, patients in which 2.4-mm TPLO plates were used were more likely to develop postoperative complications. Dogs weighing <15 kg that underwent TPLO had good short-term outcomes with minimal complications. In our study, the overall complication rate after TPLO in dogs weighing <15 kg is less than that historically reported in heavier dogs. Our data suggests that TPLO is a safe treatment option in small dogs with cranial cruciate ligament rupture.

Canine cruciate ligament ruptures: Implications for financial costs and human health

The cranial cruciate ligament (CCL) in dogs is homologous to the anterior cruciate ligament (ACL) in humans. Factors that place an individual at-risk for noncontact ruptures are not clearly defined in humans or dogs. Cyclic variation in human females as well as early spay/neuter in canines has frequently implicated hormonal variation, however these factors do not fully explain the human dimorphic or canine breed rupture rates. The present study examined dogs as a proxy model for humans to better understand the covariance. A random clinical data sample from the Oklahoma State University Veterinary Hospital was obtained on (n = 29) CCL surgical cases and nonsurgical (n = 28) controls. A statistical test for association of spay/neuter with CCL rupture was significant (chi-square = 21.7, p < .01). Sex balance between the groups was not significantly (p > .01) different. Data on other variables related to morphometric variability such as the tibial plateau angle was not available on the nonsurgical sample and comparisons could only be made to values from the literature. Though there may have been sample bias, this preliminary study found that more large than small dogs were represented in the surgical sample. Our results also support the claim that spayed/neutered dogs are more likely to rupture their CCL than intact dogs. Given the high costs of surgical repair, both for canines and humans, we argue for multivariate studies that investigate the interaction of variables in a larger subject sample which can provide comparable data on all parameters.

Effect of patellar luxation on radiographic measurements of tibial plateau angle in small-breed dogs

OBJECTIVE To determine whether medial patellar luxation would affect radiographic tibial plateau angle (TPA) measurements in small-breed dogs. DESIGN Prospective cross-sectional study. ANIMALS 15 small-breed dogs (25 stifle joints) with grade 2 or 3 medial patellar luxation (5 dogs with unilateral luxation and 10 dogs with bilateral luxation). PROCEDURES Digital mediolateral radiographic images of each affected stifle joint were acquired with the patella in manually reduced (n = 25) and luxated (25) positions. In 2 measurement sessions separated by > 48 hours, 3 observers unaware of patella status (luxated or reduced) measured the TPA in each image twice in random order. Mixed linear modeling was performed to determine the effect of patella status on TPA measurements, and intraobserver and interobserver variation in measurements were calculated. RESULTS TPA measurements by all observers differed significantly between the first and second measurement sessions, but by a mean value of only 0.7°. A few significant differences were identified between 1 pair of observers by patella status and between patella statuses for 1 observer, but all mean differences were ≤ 1.7°. No significant difference in intraobserver variation was identified between patella statuses for any observer. Interobserver variation was not affected by patella status and measurement session. CONCLUSIONS AND CLINICAL RELEVANCE Although some significant differences were identified in radiographic TPA measurements in dogs with medial patellar luxation, depending on whether the patella was luxated or manually reduced, these differences were so small they could be considered clinically unimportant. Consequently, we believe that in small-breed dogs with patellar luxation, patella status would be unlikely to have a clinically meaningful effect on the measured TPA.

Surgical stabilization of concomitant canine medial patellar luxation and cranial cruciate ligament disease

Objectives: To compare complication rates and outcomes between cases of concomitant cranial cruciate ligament (CrCL) disease and medial patellar luxation (MPL) treated using extracapsular stabilization and tibial tuberosity transposition (ECS+TTT) and tibial tuberosity transposition and advancement (TTTA).

Methods: In a multicentre retrospective study, records from four referral hospitals were reviewed for dogs with concomitant CrCL pathology and MPL treated using ECS+TTT or TTTA. Data retrieved included signalment, partial/complete CrCL tear, MPL grade, treatment performed, occurrence of postoperative complications, and postoperative outcome grade. Associations between surgical procedure and risk of complication and surgical procedure and outcome were investigated using univariable logistic regression and proportional odds logistic regression respectively. Multiple logistic regression was used to explore confounding factors.

Results: A total of 72 stifles were evaluated in 66 dogs; 32 stifles were stabilized using ECS+TTT and 40 using TTTA. Overall complications were 2.7 times more frequent in the ECS+TTT group and major complications occurred only in this group. The TTTA group was less likely to suffer complications (17.5%) compared to the ECS+TTT group (46.9%) (p = 0.009) and TTTA cases had lower odds of a poorer clinical outcome (p = 0.047).

Clinical significance: Stifles stabilized using ECS+TTT are more likely to suffer from postoperative complications and a poorer clinical outcome when compared to TTTA.

Supplementary Material to this article is available online at https://doi.org/10.3415/VCOT-16-10-0148

Distal femoral lateral closing wedge osteotomy as a component of comprehensive treatment of medial patellar luxation and distal femoral varus in dogs

OBJECTIVE

To describe a cohort of dogs with medial patellar luxation managed with a distal femoral lateral closing wedge ostectomy (DFO) as a component of comprehensive treatment, and to report radiographic and long-term clinical outcome of this technique.

METHODS

Medical records of dogs that had a lateral closing wedge DFO as part of management of medial patellar luxation at three veterinary teaching hospitals were reviewed. Surgical reports as well as the preoperative, postoperative, and follow-up radiographs were reviewed. The anatomical lateral distal femoral angle (aLDFA) was determined. Long-term clinical outcome was assessed by telephone interview with the owner.

RESULTS

A lateral closing wedge DFO was performed on 66 limbs. The mean pre- and postoperative aLDFA was 107.6° ± 5.8° and 94.1° ± 4.2°, respectively. Cranial cruciate ligament disease was identified in 28/66 affected limbs. Tibial angular deformity, torsional deformity, or both was identified in nine of the 66 limbs. Ostectomy healing was confirmed radiographically in 51/66 limbs. The mean time to union was 73 ± 37 days. All patellae were in the normal position and stable. Complications included infection (2/51), fixation failure (1/51), delayed healing (2/51), and persistent lameness (1/51).

CLINICAL SIGNIFICANCE

In this cohort of cases, DFO was a highly successful and repeatable component of surgical treatment for dogs with medial patellar luxation associated with femoral varus. This study also provides more evidence of the high rate of concurrent cranial cruciate ligament disease in cases of medial patellar luxation complicated by femoral varus, and supports an association between stifle instability and medial patellar luxation.

Combined tibial plateau levelling osteotomy and tibial tuberosity transposition for treatment of cranial cruciate ligament insufficiency with concomitant medial patellar luxation

OBJECTIVES

To describe the surgical technique and report short-term outcome for combined tibial plateau levelling osteotomy and tibial tuberosity transposition (TPLO-TTT) as an option in the treatment of cranial cruciate ligament insufficiency with concomitant medial patellar luxation.

METHODS

Medical records were reviewed (2011-2013) of dogs that underwent a standard tibial plateau levelling osteotomy followed by a tibial tuberosity transposition in the frontal plane and stabilized with pin and tension-band wire fixation as a component of surgical treatment for combined cranial cruciate ligament insufficiency and medial patellar luxation. Signalment, fixation method together with any ancillary procedures, function at the in-hospital follow-up examinations, and any complications were recorded. Healing was assessed retrospectively based on the grading criteria of the International Society Of Limb Salvage.

RESULTS

Fifteen stifle joints in 11 dogs were identified; 13 stifles were available for in-hospital follow-up. All 13 achieved union (3 with grade III/IV and 10 with grade IV/IV radiographic healing scores); mean time to healing was 10.6 (± 2.9) weeks. Patellar ligament thickening was also identified radiographically in seven of the 13 of stifle joints. All dogs were reported to have mild or no lameness at their last follow-up examination. No catastrophic or major postoperative complications occurred that required additional surgery. Patellar re-luxation did not occur in any of the 13 stifles available for in-hospital follow-up.

CLINICAL SIGNIFICANCE

The TPLO-TTT was found to be a reliable and effective technique when used as a part of the treatment of combined cranial cruciate ligament insufficiency with concomitant medial patellar luxation in this series of dogs.

Owner Evaluation of a CORA-Based Leveling Osteotomy for Treatment of Cranial Cruciate Ligament Injury in Dogs

OBJECTIVE

To evaluate a center of rotation of angulation (CORA)-based leveling osteotomy for cranial cruciate ligament injury in dogs.

STUDY DESIGN

Retrospective case series.

ANIMALS

Dogs (n=70).

METHODS

Medical records (March 2011 to March 2012) of dogs diagnosed with a cranial cruciate ligament (CCL) injury treated with a CORA-based leveling osteotomy and stabilized using a bone plate and headless compression screw were reviewed. Radiographs were reviewed for tibial plateau angle and radiographic healing at final evaluation graded on a 5-point scale. Follow-up for a minimum of 6 months postoperatively was conducted by owner completion of a questionnaire regarding their dog's function after surgery. Based on owner responses, clinical outcomes were established.

RESULTS

CORA-based leveling osteotomy was used for 70 stifles with CCL injury. The mean time to final radiographic recheck was 107 days (range, 32-424 days). Radiographic healing scores were 42 dogs (69%) with grade 4, 17 dogs (28%) with grade 3, and 2 dogs (3%) with grade 2. The mean time to follow-up was 11.9 months (range 6-18 months). Fifty-four of the 70 (77%) dogs had full function, 13 (19%) had acceptable function, and 3 (4%) had unacceptable function. Complications occurred in 11 stifles (16%), including 3 incisional, 6 late-onset meniscal tears, and 2 implant related.

CONCLUSION

The described method of a CORA-based leveling osteotomy can be successfully performed for treatment of CCL injury in dogs. At the time of mid-term and long-term owner follow-up, most dogs in this case series had returned to full function.

Efficacy of Postoperative Antimicrobial Use for Clean Orthopedic Implant Surgery in Dogs: A Prospective Randomized Study in 100 Consecutive Cases

OBJECTIVES

To investigate whether administration of postoperative oral antimicrobial drugs has a beneficial effect on preventing surgical site infections (SSI) in clean orthopedic surgery involving stainless steel plating systems.

STUDY DESIGN

Randomized prospective clinical study.

ANIMALS

Dogs (n = 97).

METHODS

One hundred consecutive cases (97 dogs) that had clean orthopedic surgery requiring stainless steel plate fixation were randomly assigned using a random number generator to either YES group (administration of postoperative oral antimicrobials) or NO group (no administration of postoperative oral antimicrobials). Dogs in YES group were administered oral cefalexin or potentiated amoxicillin for 7 days, whereas dogs in NO group were discharged without oral antibiotics. Minimum follow-up was 12 months. Multivariable logistic regression was used to determine risk factors for SSI.

RESULTS

Overall postoperative infection rate was 12.9%. Infection occurred in 2 cases (4.3%) administered postoperative oral antimicrobials and in 10 cases (21.3%) not administered postoperative antimicrobials. Total anesthetic time and use of oral antimicrobials were the only significant factors associated with SSI. Use of postoperative antimicrobials was associated with a significant reduction in the risk of infection by ~84% and risk of infection was increased by ~2% for each minute increase in anesthesia time.

CONCLUSIONS

Administration of oral postoperative antimicrobials had a protective effect against development of SSI in clean orthopedic implant surgery.

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.