Excessive Tibial Plateau Angle Research Articles

Double-Cut Tibial Plateau Leveling Osteotomy for the Management of Cranial Cruciate Ligament Insufficiency in Dogs with an Excessive Plateau Angle: Early Clinical Results in 16 Dogs.

To describe a modification of the tibial plateau leveling osteotomy technique wherein a double cut is made in the same plane to level the tibial plateau (double-cut tibial plateau leveling osteotomy [DCTPLO]) for treating dogs with cranial cruciate ligament (CrCL) and excessive tibial plateau angle (eTPA) diseases. The DCTPLO technique was performed on 18 stifles in dogs with CrCL and an eTPA (>34°). This study evaluated the accuracy of preoperative planning, feasibility of the technique, postoperative clinical outcomes, radiographic examinations at the postoperative follow-up for the first 120 days, evolution of the tibial plateau angle (TPA), time of union of the osteotomy, apposition of the implants, and possible complications. The described technique proved to be feasible for clinical application, with reproducibility from preoperative planning. An effective reduction in the eTPA levels was observed. The mean preoperative and postoperative TPA values were 39.4° (36°-43.5°) and 6.3° (3°-13°), respectively. Radiographic healing time was 60 days in 17/18 of stifles. Minor complications (not requiring surgical review or clinical treatment) were observed in 4/18 of stifles. The DCTPLO technique was effective for treating CrCL disease with TPA of up to 43.5° in dogs.

Three-dimensional-printed patient-specific guides for tibial deformity correction in small-breed dogs.

To describe the use of patient-specific 3-D-printed osteotomy, reduction, and compression guides for tibial closing wedge osteotomy in small-breed dogs. 6 dogs with unilateral tibial deformities. Six small-breed dogs with 1 or a combination of tibial deformities, including excessive tibial plateau angle, valgus, and torsion, were scheduled to undergo tibial closing wedge osteotomy using patient-specific 3-D-printed osteotomy, reduction, and compression guides. The location and orientation of the wedge osteotomy were determined based on CT data using computer-aided design software. After the tibial deformities were corrected, postoperative CT or radiographs were obtained to compare the achieved tibial limb angles with the planned angles. Clinical evaluation and radiographic follow-up were performed on all dogs. Guides were successfully positioned at each specific location, and osteotomies were performed without radiation exposure or observer assistance in all dogs. Tibial deformities were corrected with angular errors of 1.8 ± 1.4°, 2.3 ± 2.1°, and 2.6 ± 1.3° in the sagittal, frontal, and transverse planes, respectively. Mild complications resolved within 1 month in 3 dogs, and revision surgery was not required. Five dogs improved to the normal gait (mean, 14.8 ± 6.6 weeks), and 1 dog recovered a satisfactory gait 24 weeks after surgery. All limbs healed 14 ± 4.7 weeks after surgery. Patient-specific 3-D-printed osteotomy, reduction, and compression guides can provide effective assistance allowing accurate correction of tibial deformities. Their use yields good clinical outcomes in small-breed dogs.

Morphologic impact of four surgical techniques to correct excessive tibial plateau angle in dogs: A theoretical radiographic analysis.

To determine morphologic differences between four tibial osteotomy techniques used to correct excessive tibial plateau angle (eTPA). Retrospective radiographic analysis. Sixteen dogs (27 tibias) with eTPA. Virtual corrections of eTPA were performed on sagittal plane radiographs of canine tibia using four tibial osteotomy techniques and categorized into respective groups. Group A represented the center of rotation of angulation (CORA)-based leveling osteotomy (CBLO) and coplanar cranial closing wedge ostectomy (CCWO), Group B the tibial plateau leveling osteotomy (TPLO) and CCWO, Group C the modified CCWO (mCCWO), and Group D the proximal tibial neutral wedge osteotomy (PTNWO). Pre- and post-correction TPA, tibial length and mechanical cranial distal tibial angle (mCrDTA) were measured and compared. Mean TPA prior to correction was 42.67 ± 6.1°. Post-correction mean TPAs were 10.47 ± 2.1°, 6.77 ± 1.6°, 4.76 ± 1.5°, and 7.09 ± 1.3° for Groups A, B, C, and D, respectively. TPA correction accuracy in Groups A and D varied least from target TPAs. Tibial shortening was documented in Group B in contrast to other groups. The greatest mechanical axis shift was identified in Group A. Each technique achieved TPA < 14° despite having different effects on tibial morphology including alteration of tibial length, mechanical axis shift and variation in correctional accuracy. Despite all methods being able to correct eTPA, the choice of technique will affect morphology in unique ways and should be considered prior to surgery to consider the implications in a given patient.

Radiographic Comparison of Virtual Surgical Corrective Options for Excessive Tibial Plateau Angle in the Dog.

The main aim of this study is to compare the impact of six proximal tibial osteotomies on the geometry and alignment of tibias with and without excessive tibial plateau angle (TPA). Mediolateral radiographs of 30 canine tibias were divided into three groups (n = 10/group): moderate TPA (≤34 degrees), severe TPA (34.1-44 degrees) and extreme TPA (>44 degrees). Six proximal tibial osteotomies were simulated on each tibia using orthopaedic planning software: cranial closing wedge ostectomy (CCWO), modified CCWO (mCCWO), isosceles CCWO (iCCWO), neutral isosceles CCWO (niCCWO), tibial plateau levelling osteotomy with CCWO (TPLO/CCWO) and coplanar centre of rotation of angulation-based levelling osteotomy (coCBLO). All tibias were reduced to a standard target TPA. Pre- and postoperative measurements were obtained for each virtual correction. Compared outcome measures included tibial long axis shift (TLAS), cranial tibial tuberosity shift (cTTS), distal tibial tuberosity shift (dTTS), tibial shortening and osteotomy overlap. Across all TPA groups, TPLO/CCWO had the lowest mean TLAS (1.4 mm) and dTTS (6.8 mm); coCBLO had the largest TLAS (6.5 mm) and cTTS (13.1 mm); CCWO had the largest dTTS (29.5 mm). CCWO had the largest degree of tibial shortening of 6.5 mm, while mCCWO, niCCWO and coCBLO resulted in minimal tibial lengthening (1.8-3.0 mm). These trends were generally conserved across different TPA groups. All findings had a p-value less than 0.05. mCCWO balances moderate alterations to tibial geometry while preserving osteotomy overlap. The TPLO/CCWO has the least effect on tibial morphology alteration, whereas the coCBLO results in the largest alteration.

Surgical and medical management in the treatment of proximal tibial metaphyseal fracture in immature dogs.

The purpose of this study was to report approaches to surgical and medical management of proximal tibial metaphyseal fractures (PTMF) and short-term case outcome. Medical records of immature dogs with PTMF were reviewed and data were collected including history, signalment and side affected. Data pertaining to surgical and medical management including radiographic evaluation and short-term complications were recorded. Forty-five dogs with a total of 47 PTMF identified and treated between 2007-2019 were included in this study. Six cases were managed with external coaptation alone. Forty-one cases were treated surgically with constructs including K-wires in different configurations, bone plate and screws, and external skeletal fixation. Of the cases managed conservatively, 4 developed complications, including bandage sores, diffuse osteopenia of the tarsus/metatarsus, and angular limb deformities. Surgical complications including pin migration necessitating removal, osteopenia, and screw placement in the proximal tibial growth plate or into the stifle joint were found in 16 cases. PTMF treated with surgery had a subjectively more predictable outcome compared to those treated with external coaptation alone. Conservative management may result in complications including development of excessive tibial plateau angle (TPA) as well as distal tibial valgus.

Excessive Tibial Plateau Angle Correction Diminishes Cruciate Degeneration.

Excessive Tibial Plateau Angle Correction Diminishes Cruciate Degeneration.

Double-cut center of rotation of angulation–based leveling osteotomy for treatment of cranial cruciate ligament deficiency and excessive tibial plateau angle secondary to growth anomaly in two dogs

A 4-year-old female Staffordshire Bull Terrier (dog 1) and a 6-year-old male Yorkshire Terrier (dog 2) were evaluated because of left pelvic limb lameness. Both dogs had a partial rupture of the left cranial cruciate ligament associated with a unilateral excessive tibial plateau angle (51° in dog 1 and 41° in dog 2) secondary to a growth anomaly. Both dogs underwent a double-cut center of rotation of angulation-based leveling osteotomy combining rotation of the proximal fragment with a cranial closing wedge ostectomy. The procedure allowed leveling of the tibial plateau to a final angle of 11° in one dog and 10° in the other without perioperative complications. Both dogs had excellent functional outcomes ≤ 4 months after the surgery. No postoperative complications were reported during follow-up (12 months and 9 months for dogs 1 and 2, respectively). Results for these dogs suggested that double-cut center of rotation of angulation-based leveling osteotomy can be considered as a viable treatment option for cranial cruciate ligament deficiency associated with excessive tibial plateau angle.

Prophylactic Efficacy of Tibial Plateau Levelling Osteotomy for a Canine Model with Experimentally Induced Degeneration of the Cranial Cruciate Ligament

The aim of this study was to clarify the histological effects of tibial plateau levelling osteotomy on cranial cruciate ligament degeneration induced by excessive tibial plateau angle. Five female Beagles were used to bilaterally create excessive tibial plateau angle models surgically. A second tibial plateau levelling osteotomy was performed 11 months after the first surgery on the right stifle (tibial plateau levelling osteotomy group), and a sham operation that did not change the tibial plateau angle was performed on the left stifle (excessive tibial plateau angle group). At 6 months after the second surgery, the dogs were euthanatized. The cranial cruciate ligament was stained with haematoxylin-eosin to assess the cell density, Alcian-Blue to assess proteoglycans and Elastica-Eosin to assess elastic fibres, and immunohistochemically stained to assess type I (COL1) and type II collagen and SRY-type HMG box 9 (SOX9) expression. In each group, the cranial cruciate ligament degeneration, especially on the tibial side, including the presence of Alcian-Blue- and Elastica-Eosin-positive regions, decreased in COL1-positive regions, and enhancement of SOX9 expression was observed. Besides, compared with the tibial plateau levelling osteotomy group, the excessive tibial plateau angle group showed increases in Alcian-Blue- and Elastica-Eosin-positive regions and a decrease in the COL1-positive regions. The results suggested that excessive tibial plateau angle-induced cranial cruciate ligament degeneration can be suppressed by reducing the biomechanical load on the cranial cruciate ligament by performing tibial plateau levelling osteotomy.

Investigation of the effects of excessive tibial plateau angle and changes in load on ligament tensile forces in the stifle joints of dogs.

To investigate the effect of an excessive tibial plateau angle (TPA) and change in compressive load on tensile forces experienced by the cranial cruciate, medial collateral, and lateral collateral ligaments (CCL, MCL, and LCL, respectively) of canine stifle joints. 16 cadaveric stifle joints from 16 orthopedically normal Beagles. Stifle joints were categorized into unchanged (mean TPA, 30.4°) and excessive (mean TPA before and after modification, 31.2° and 41.1°, respectively) TPA groups. The excessive TPA group underwent a TPA-increasing procedure (curvilinear osteotomy of the proximal aspect of the tibia) to achieve the desired TPA. A robotic system was used to apply a 30- and 60-N compressive load to specimens. The craniomedial band of the CCL, caudolateral band of the CCL, MCL, and LCL were sequentially transected; load application was repeated after each transection. Orthogonal force components were measured in situ. Forces on ligaments were calculated after repeated output force measurements as the contribution of each component was eliminated. Increasing the compressive load increased tensile forces on the craniomedial and caudolateral bands of the CCL, but not on the MCL or LCL, in specimens of both groups. At the 60-N load, tensile force on the craniomedial band, but not other ligaments, was greater for the excessive TPA group than for the unchanged TPA group. Results indicated that stress on the CCL may increase when the compressive load increases. The TPA-increasing procedure resulted in increased tensile force on the CCL at a 60-N compressive load without affecting forces on the MCL or LCL.

Técnica de placa dupla para fixação concomitante da osteotomia de nivelamento do platô tibial e ostectomia modificada em cunha de fechamento cranial da tíbia em um cão com doença do ligamento cruzado cranial e ângulo de platô tibial excessivo: relato de caso

ABSTRACT Tibial plateau leveling osteotomy (TPLO) associated to cranial wedge closing ostectomy (CCWO) has been one of the best options to manage cranial cruciate ligament (CCL) disease and excessive tibial plateau angle (TPA) in large dogs, however, the complication rate is potentially high. It is believed that a more robust fixation is necessary to stabilize them and decrease the risk of implant failure. A 6-year-old male American Pit Bull, weighing 36kg, with 90-day history of right hind limb lameness, was diagnosed with CCL disease. Due to the excessive tibial plateau angle (42°), TPLO was associated with a modified CCWO using a double plating technique. A final TPA of 12⁰ was accomplished, and a restricted level of exercises and physiotherapy were recommended. The patient was followed monthly until the fifth month postoperatively, when radiographic bone consolidation and no lameness were observed. By the date of this submission, 3 years after the procedure, the owner has reported no complications. The double plating technique for fixing TPLO and modified CCWO proved to be effective for the treatment of CrCL deficiency in a large dog with an excessive TPA.

Center of rotation of angulation-based leveling osteotomy combined with a coplanar cranial closing wedge ostectomy to manage cranial cruciate ligament insufficiency in dogs with excessive tibial plateau angle.

To describe outcomes of dogs with excessive tibial plateau angle (eTPA) and cranial cruciate ligament (CrCL) disease treated with center of rotation of angulation-based leveling osteotomy (CBLO) and cranial closing wedge ostectomy (CCWO). Retrospective study. Twenty-one dogs. Medical records of dogs with CrCL disease and eTPA (>34°) treated with CBLO/CCWO were reviewed. Signalment, body weight, intra-articular structure appearance, TPA (preoperatively, postoperatively, and at osteotomy healing), postoperative function, and complications were recorded. Twenty-one dogs (28 stifles) with CrCL disease/eTPA underwent CBLO/CCWO. Twenty stifles had complete CrCL tears and eight tears were partial. Mean age and weight of dogs were 4 years (range, 1-9) and 27 kg (range, 4-65), respectively. Medial menisci were normal in 20 stifles, torn in 5, and degenerative in 3. All lateral menisci were normal. The caudal cruciate ligament was normal in 26 stifles and partially torn in 2. Mean TPA was 43° preoperatively, 10° postoperatively, and 10° at final recheck. Grade 4 healing occurred in all osteotomies by 8 weeks postoperatively. Complications included one pin migration, breakage of two proximal screws (1 case), one late-onset caudolateral band CrCL tear, two late-onset meniscal tears, and one surgical site infection. Eighteen dogs returned to full function, and three dogs achieved acceptable function, at a mean of 27 months. Center of rotation of angulation-based leveling osteotomy/CCWO resulted in grade 4 osteotomy healing by 8 weeks, minimal complications, and acceptable to full return to function. Center of rotation of angulation-based leveling osteotomy/CCWO should be considered to treat canine CrCL disease/eTPA.

Caudal Cruciate Ligament Rupture in an Adult Dog 8.5 Years Post Juvenile Tibial Plateau Cranial Hemiepiphysiodesis

AbstractThe aim of this study was to report a case of caudal cruciate ligament rupture in a 9-year-old dog who underwent juvenile tibial plateau cranial hemiepiphysiodesis that was performed to treat a partial cranial cruciate ligament rupture and excessive tibial plateau angle. A 9-year-old, 45 kg, male Bernese Mountain dog was referred for a non-traumatic acute right pelvic-limb lameness. At the age of 5 months, the dog underwent bilateral tibial plateau cranial hemiepiphysiodesis to treat a bilateral partial cranial cruciate ligament rupture and excessive tibial plateau angles. At clinical examination, a caudal tibial subluxation of the right stifle was detected. The right tibial plateau angle was 3 degree. Arthroscopy confirmed a complete caudal cruciate ligament rupture. The cranial cruciate ligament was partially torn. A diagnosis of caudal cruciate ligament rupture 8.5 years post juvenile tibial plateau hemiepiphysiodesis was made. A tibial plateau overcorrection might have contributed to caudal cruciate ligament rupture in this dog.

Modified cranial closing wedge osteotomy for treatment of cranial cruciate ligament insufficiency in dogs with excessive tibial plateau angles: Technique and complications in 19 cases

To describe short-term outcomes of a modified cranial closing wedge osteotomy (CCWO) for treatment of dogs with cranial cruciate ligament disease and excessive tibial plateau angle (eTPA). Retrospective clinical study. 18 client-owned dogs (19 stifles) with cranial cruciate ligament disease and eTPA (>34°). A modified CCWO was performed with Kirschner wires as osteotomy alignment aids. A juxta-articular neutral wedge osteotomy equal in angle to the preoperative TPA was performed. Fixation was achieved with a tibial plateau leveling osteotomy (TPLO) plate and tension band wire apparatus (89%) or a TPLO plate (11%). Preoperative and postoperative, and recheck TPA, cranial tibial long axis shift, and major and minor complications were recorded. The mean preoperative TPA (49.5° ± 6.7°) was reduced postoperatively (8.3° ± 4.8°). Four of 19 joints (21%) developed 2 major and 3 minor complications during the intraoperative and follow-up period (577 day mean in-hospital recheck). Two cases were diagnosed with surgical site infections requiring implant removal for resolution. Fixation failure or implant complications were not observed in any dog during the limited radiographic follow-up period. All dogs were sound or recovering as expected, with 15/19 dogs (79%) showing complete radiographic osteotomy healing at their final in-hospital follow-up examination. Modified CCWO should be considered for the treatment of cranial cruciate ligament disease in dogs with eTPA. In this case series, the described technique was associated with uneventful osteotomy healing without implant failures in all dogs, although radiographic follow-up was limited in some cases.

Histological and immunohistological analysis of degenerative changes in the cranial cruciate ligament in a canine model of excessive tibial plateau angle.

To create a canine model of excessive tibial plateau angle (eTPA) and assess the chondroid metaplasia and extracellular matrix alteration in the cranial cruciate ligament. Seven mature female Beagles were included. Cylindrical osteotomy was performed bilaterally in the proximal tibia. The TPA was increased to approximately 40° in the left tibia (eTPA stifle) and left unchanged in the right tibia (control stifle). Exercise stress was started at three months postoperatively, and at 12 months postoperatively the dogs were euthanatized and the cranial cruciate ligaments were collected. The specimens were subjected to haematoxylin and eosin staining to assess the ligamentocyte morphology and immunostaining to assess the type I (COLI), type II (COLII), and type III (COLIII) collagen, and the sry-type HMG box 9 (SOX9) staining. Macroscopic cranial cruciate ligament injury was absent in six dogs but present in the eTPA stifle of one dog, which was excluded from the analysis. The ligamentocyte density decreased and the percentage of round ligamentocytes increased in the eTPA stifles. The COLII, COLIII, and SOX9 staining increased significantly and COLI deposition decreased in the eTPA stifles compared to the control stifle. The extracellular matrix changed, COLI deposition decreased, and COLIII and SOX9 staining increased in the cranial cruciate ligament of the eTPA stifles. SOX9 may contribute to COLII synthesis in the extracellular matrix of the cranial cruciate ligament in eTPA stifles, and eTPA may promote chondroid metaplasia and extracellular matrix alteration.

Combination Tibial Plateau Leveling Osteotomy and Transverse Corrective Osteotomy of the Proximal Tibia for the Treatment of Complex Tibial Deformities in 12 dogs

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. Cases series. Dogs (n=12; 19 stifle joints). 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. 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. 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.

Modification of the cranial closing wedge ostectomy technique for the treatment of canine cruciate disease

To describe a modification of the cranial closing wedge ostectomy (CCWO) technique and to compare its efficacy to the standard technique on cadaveric specimens. The standard and modified CCWO technique were applied to eight pairs of cadaveric tibiae. The following parameters were compared following the ostectomy: degrees of plateau levelling achieved (degrees), tibial long axis shift (degrees), reduction in tibial length (mm), area of bone wedge removed (cm²), and the area of proximal fragment (cm²). The size of the removed wedge of bone and the reduction in tibial length were significantly less with the modified CCWO technique. The modified CCWO has two main advantages. Firstly a smaller wedge is removed, allowing a greater preservation of bone stock in the proximal tibia, which is advantageous for implant placement. Secondly, the tibia is shortened to a lesser degree, which might reduce the risk of recurvatum, fibular fracture and patella desmitis. These factors are particularly propitious for the application of this technique to Terrier breeds with excessive tibial plateau angle, where large angular corrections are required. The modified CCWO is equally effective for plateau levelling and results in an equivalent tibial long-axis shift. A disadvantage with the modified technique is that not all of the cross sectional area of the distal fragment contributes to load sharing at the osteotomy.

Comparison of Surgical Treatment Options for Cranial Cruciate Ligament Disease in Large‐Breed Dogs with Excessive Tibial Plateau Angle

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. Multicenter, case-control study. eTPA group (TPA>or=35 degrees)=58 dogs (78 stifles); control group (TPA<or=30 degrees)=58 dogs (72 stifles). 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, chi(2) tests, and t-tests were calculated to discern differences between eTPA and control-group dogs. TPLO was the most common treatment for eTPA. Owner-perceived outcome was superior for eTPA group dogs when TPLO resulted in TPA<or=14 degrees compared with those with postoperative TPA>14 degrees. 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. Surgical treatment of dogs with eTPA has a higher complication rate, but comparable outcome to that of dogs without eTPA. Postoperative TPA<or=14 degrees and addition of ancillary implants are recommended when using TPLO to treat dogs with eTPA.

Risk factors for excessive tibial plateau angle in large-breed dogs with cranial cruciate ligament disease

To identify risk factors for development of excessive tibial plateau angle (TPA) in large-breed dogs with cranial cruciate ligament disease (CCLD). Case-control study. 58 dogs with excessive TPAs (ie, TPA >or= 35 degrees ; case dogs) and 58 dogs with normal TPAs (ie, TPA <or= 30 degrees ; control dogs). Medical records and radiographs were reviewed and owners were interviewed to identify potential risk factors for excessive TPA. Case dogs were 3 times (95% confidence interval, 1.2 to 8.0) as likely to have been neutered before 6 months of age as were control dogs. Case dogs with TPA >or= 35 degrees in both limbs were 13.6 times (95% confidence interval, 2.72 to 68.1) as likely to have been neutered before 6 months of age as were control dogs with TPA <or= 30 degrees in both limbs. Case dogs were significantly younger at the onset of hind limb lameness than were control dogs. Results suggested that early neutering was a significant risk factor for development of excessive TPA in large-breed dogs with CCLD. Further research into the effects of early neutering on TPA and the pathophysiology of CCLD is warranted.

Combination Tibial Plateau Leveling Osteotomy and Cranial Closing Wedge Osteotomy of the Tibia for the Treatment of Cranial Cruciate Ligament‐Deficient Stifles with Excessive Tibial Plateau Angle

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