Postoperative Tibial Plateau Angle Research Articles

Effect of tibial plateau angle < 5° on ground reaction forces in dogs treated with tibial plateau leveling osteotomy for cranial cruciate ligament rupture up to 6 months postoperatively

Tibial plateau leveling osteotomy (TPLO) has been commonly performed in dogs with cranial cruciate ligament disease (CCLD) since the introduction by Slocum and Slocum (1993). To reduce cranial tibial thrust the TPLO technique aims for a postoperative tibial plateau angle (TPA) of 5–6.5°. In recent years studies have shown that a postoperative TPA below 5° could be beneficial regarding stifle stability or meniscal load. Dogs with CCLD that were treated with TPLO, were examined preoperatively, six weeks, three and six months postoperatively with gait analysis and grouped according to their postoperative TPA. The aims of study was (1) to evaluate if dogs with a postoperative TPA below 5° would have a faster limb function recovery up to six months postoperatively as measured objectively with ground reaction forces (GRFs) and (2) to determine whether the postoperative TPA correlates with the outcome measurements. Dogs with TPA <5° showed no faster limb function recovery postoperatively up to six months as measured with peak vertical force (PVF) or vertical impulse (VI) (p > 0.05). No correlation for the postoperative TPA <5° on GRFs was demonstrated. But the postoperative TPA showed a significant correlation with the symmetry indices of PVF (SIPVF) and VI (SIVI) for all dogs (>5° and <5° TPA together), indicating that with lower postoperative TPA dogs had a more symmetrical gait in hindlimbs SIPVF (r = 0.144, p < 0.05) and SIVI (r = 0.189, p < 0.01). The study indicates that a lower postoperative TPA could be beneficial regarding hindlimb symmetry indices of GRFs.

Cadaveric comparison of two techniques for intraoperative placement of tibial plateau levelling osteotomies in dogs.

Both tibial tuberosity fractures and deviation from the planned postoperative tibial plateau angle have been associated with poor centring of tibial plateau levelling osteotomies (TPLOs). The aim of this cadaveric study was to compare two techniques for centring the osteotomy and preserving the tibial tuberosity width (TTW). Stifle radiographs were obtained from 20 limbs of 10 dogs. TPLO was planned on each stifle, and a two-wire technique (TWT) and a technique using the medial collateral ligament (MCL) as an intraoperative landmark were planned. The techniques were executed and marked with radiopaque pins. Further radiographs were obtained and analysed. On average, TWT resulted in a 20.4% increase in TTW and medial collateral ligament technique (MCLT) resulted in a 13.4% decrease. Expressed as a percentage of the radial saw size, the average error in the centring of the osteotomy arising from the TWT was 13.4% and that from the MCLT was 14.2%. This study had a small sample size and involved a single surgeon. Neither technique reliably identified the desired centre of the osteotomy, and both had a similar magnitude of error. MCLT resulted in reduced TTW, while TWT resulted in increased TTW. A reduced TTW has been associated with an increased risk of tibial tuberosity fracture, so MCLT is not recommended for clinical use.

Cranial closing wedge ostectomies for management of canine cranial cruciate ligament insufficiency: Comparison and geometric modelling of errors

Variants of the cranial closing wedge ostectomy (CCWO) may be used to manage cranial cruciate ligament deficient stifles by reduction of the tibial plateau angle (TPA). Concerns have been raised about predictability of achieving target TPA, limb shortening, axis shift, and distalization of the tibial tuberosity.Landmarks derived from tibial radiographs (n = 50) by 5 observers, along with outlines of the cranial and caudal proximal tibial cortices, were used to simulate six CCWO variants. Tested variants were Slocum-type (n = 2), modified (n = 2), isosceles, and anatomical-mechanical axis (AMA)-based CCWO. Observer specific landmarks were used to model pre- and postoperative errors in TPA measurement. Mean landmarks were used to compare key outcome variables between the variants, as well as modelling errors in positioning the wedge apex.Variants differed markedly in TPA, axis shift, mechanical axis length changes, and tibial tuberosity distalization, with more proximally positioned wedges performing better than distally positioned wedges. Errors in TPA identification appeared partially self-correcting due to altered axis shifts. Craniocaudal shifts in wedge apex position had the most severe effects on outcome variables, especially in shorter tibiae with greater initial TPA values.Recent CCWO variants are likely to achieve a satisfactory postoperative TPA with limited axis shift. The AMA-based CCWO technique appears to influence MA length and tibial tuberosity position the least, and apart from the effect on TPA where no advantage could be discerned, it appeared more robust in the face of wedge apex positioning errors than the other techniques.

A modified triple tibial osteotomy for management of canine cranial cruciate ligament disease: retrospective assessment of 309 procedures (2017–2020)

ABSTRACTCase historyMedical records from a single referral hospital (Animal Referral Hospital, Sinnamon Park, Australia) of dogs treated with modified triple tibial osteotomy (TTO) for management of cranial cruciate ligament (CrCL) disease from June 2017 to June 2020 were reviewed. Modifications to the originally described TTO procedure included a modified wedge angle calculation and performing the tibial osteotomies without the use of pre-drilled guide holes.Clinical findingsA total of 253 dogs met the inclusion criteria. Two dogs were excluded, leaving 251 dogs that had undergone 309 procedures for assessment, and data from these, including complications, were reviewed. Complete, partial competent, and partial incompetent rupture of the cranial cruciate ligament was identified in 202/309 (65.4%), 79/309 (25.6%), and 28/309 (9.1%) stifles, respectively. Medial meniscal injury was identified in 207/309 (67.0%) stifles at the time of initial surgery.Treatment and outcomeFifty-eight dogs had bilateral procedures, including both single-session and staged surgeries, and 48 of these were available for analyses. The modifications to the TTO procedure described herein resulted in a median wedge angle of 21° and a median post-operative tibial plateau angle of 5.8°. Tibial compression testing following surgery indicated elimination of cranial tibial thrust in all stifles in this series. The most common intra-operative complication was tibial tuberosity fracture (15/309; 4.9%). Minor post-operative complications occurred in 37/309 (12.0%) procedures, with infection being the most common (27/309; 8.7%). Major post-operative complications occurred in 9/309 (2.9%) procedures. The intra- and post-operative complication rates for dogs undergoing bilateral single-session TTO were both 8.3% (2/24). The intra- and post-operative complication rates for dogs undergoing bilateral staged TTO were both 4.2% (1/24). The low number of complications for both the bilateral single-session and bilateral staged TTO groups precluded statistical analysis. All complications resolved uneventfully as determined by the attending surgeon.Clinical relevanceThe modified TTO technique described here was safe and effective for the management of canine CrCL disease in the dogs included in the case series. Findings of this study suggest that, with careful case selection, the modified TTO may be performed as a bilateral single-session procedure in dogs with concurrent bilateral cranial cruciate ligament disease. Future studies analysing the effects of these modifications on stifle biomechanics would be beneficial.AbbreviationsCrCL: Cranial cruciate ligament; SSI: Surgical site infection; TPA: Tibial plateau angle; TPLO: Tibial plateau levelling osteotomy; TTA: Tibial tuberosity advancement; TTO: Triple tibial osteotomy

Predicting tibial plateau angles following four different types of cranial closing wedge ostectomy.

To investigate how tibial long axis (TLA) shift affects the postoperative tibial plateau angle (TPA) in four cranial closing wedge ostectomy (CCWO) techniques. In silico study. A total of 15 client-owned dogs. Computed tomography (CT) scans of 15 client-owned dogs were reviewed using an open-source 3D computer graphics editor. Each computer-generated 3D tibia model underwent a CCWO, with cranial cortex alignment, in 10° increments up to 70° using each of the four previously described techniques. The TLA shift, TPA and mechanical tibial length (mTL) were calculated, using trigonometry, for each model. Equations for predicting final TPA were generated with linear regression. A total of 433 3D computer generated tibial models were analyzed. With each technique, the TPA varied in a linear fashion within the studied range of wedge angles. The TLA shift and tibial shortening magnitude varied between the four different CCWO techniques, with maximum mTL reduction of ranging from 7.5% to 40.9%. All predicted TPAs using the generated equations were within the target range of 4-6°. A linear relationship between ostectomy wedge angle and TPA correction was observed in this study, which allowed for generation of accurate corrective equations. These results allow extrapolation of the wedge angle required to reach a postoperative TPA of 5°, by considering the TLA shift. The use of the generated corrective equations may thus increase CCWO planning precision.

Use of a jumbo plate in dogs greater than 50 kg following tibial plateau leveling osteotomy does not prevent increase in tibial plateau angle through convalescence.

To investigate the use of a locking 3.5/4.0-mm jumbo tibial plateau leveling osteotomy (TPLO) plate in maintaining the postoperative tibial plateau angle (TPA) in giant-breed dogs weighing > 50 kg and to report the associated complications. Canine patients weighing > 50 kg that underwent TPLO stabilized with a locking 3.5/4.0-mm jumbo TPLO plate between January 2017 and May 2022. Retrospective case series retrieving postoperative outcomes from the medical records. Healing scores and TPAs were calculated using postoperative and recheck radiographs. Owner-perceived outcomes were obtained via questionnaire. 24 stifles in 22 dogs were included. Postoperative complications were recorded in 11 of 24 cases (45.8%) inclusive of 1 minor, 1 catastrophic, and 9 major complications. A statistically significant increase in TPA over the convalescent period was found. Grade 4 healing was present in 18 of 24 (75%) stifles, while the remainder were scored as grade 3. The use of a locking 3.5/4.0-mm jumbo TPLO plate did not prevent a statistically significant increase in TPA through convalescence. This procedure displayed an unacceptably high complication rate when compared with contemporary literature of TPLO. Despite a high complication rate in this patient population, most complications were successfully managed with medical and/or surgical treatment, and high mean and median healing scores were achieved at the radiographic recheck. Additionally, owner-perceived long-term outcomes were excellent.

A mismatch of planning and achieved tibial plateau angle in cranial closing wedge surgery: An in silico and clinical evaluation of 100 cases.

(1) To determine whether Oxley's modified cranial closing wedge osteotomy (CCWO) results in a tibial plateau angle (TPA) of 5° in silico, (2) compare in silico to clinical postoperative TPA and (3) determine the impact of ostectomy distalization in silico. Cross-sectional retrospective radiographic in silico study. A total of 100 stifle radiographs; 90 dogs (small ≤25 kg = 84; large >25 kg = 16). Tibial plateau angles were measured preoperatively (TPAPre ), after in silico planning (TPAPlan ), and postoperatively (TPAPost ). Virtual ostectomies were evaluated for plate fit. Postoperative ostectomy position was measured. Virtual ostectomies were performed 5/7.5/10/15 mm from the patellar tendon insertion in 10 dogs from each preoperative TPA category (≤20°/21-25°/ 26-30°/31-35°/>35°). Comparisons for TPAPre , TPAPost , and TPAPlan were made between small and large dogs, and the outcome to the target 5° between TPA categories and ostectomy positions. Mean ± SD TPAPre was 28.6 ± 6.2° and higher in small than large dogs. Mean TPAPlan was 7.6 ± 2.7°. Plate fit was appropriate in all. In silico, TPAs were greater than 5° except for cases with TPAPre > 35°. Median TPAPost was 5.5° (-4-21) and was higher in small (7°) than large (4.5°) dogs. Postoperative ostectomy position was more distal than Oxley's guidelines. When distalized >7.5 mm in silico, the magnitude of under-correction increased. Oxley's modified CCWO did not result in TPA of 5° in most cases. Ostectomy distalization exacerbated under-correction. Current guidelines should be modified to achieve 5° TPA postoperatively.

Preoperative planning using computed tomography in tibial plateau levelling osteotomy: A comparison with conventional radiography.

BackgroundTibial plateau levelling osteotomy (TPLO) is currently one of the most common surgical procedures for the correction of the stifle joint with a ruptured cranial cruciate ligament. TPLO is based on the preoperative tibial plateau angle (TPA); therefore, it is essential to optimise the consistency and repeatability of TPA measurements.ObjectivesThis study aims to compare computed tomography (CT) with conventional radiography in the preoperative planning of TPLO.MethodsThis prospective study included six dogs (12 hindlimbs) and 13 canine cadaveric hindlimbs. In the six beagle dogs, TPAs were measured by three radiologists using digital radiographic and CT images to evaluate the intra‐ and inter‐observer agreement. To evaluate the intra‐observer agreement of the TPA before and after surgery, and the intended angle of the postoperative TPA according to the preoperative planning method, 13 cadaveric hindlimbs were evaluated thrice at random by a single radiologist.ResultsThe intra‐ and inter‐observer intraclass correlation coefficients (ICCs) of the CT method were higher than those of the radiographic method in normal beagle dogs. The intra‐observer ICC of the CT method before and after TPLO was generally higher than that of the radiographic method in the cadaver. However, no significant difference was noted in the evaluation of the intended postoperative TPA according to the preoperative planning method.ConclusionsThe intra‐ and inter‐observer ICCs allowed for easy identification of landmarks required to consistently determine the TPA in the preoperative planning of TPLO based on CT images.

Efficacy of a Customized Three-Dimensional Printing Surgical Guide for Tibial Plateau Leveling Osteotomy: A Comparison With Conventional Tibial Plateau Leveling Osteotomy.

Objective: To prospectively evaluate the effect of a computed tomography (CT)-based three-dimensional (3D) printing surgical guide on surgical accuracy of tibial plateau leveling osteotomy (TPLO).Study Design: Cadaveric study.Animals: Canine cadaveric hindlimbs (n = 14).Methods: TPLO was performed on cadaver hindlimbs disarticulated at the coxofemoral joint to compare and evaluate the conventional TPLO method (n = 7) with one that used customized 3D printing surgical guides (n = 7). The operation time and postoperative tibial plateau angle (TPA) of the osteotomy were evaluated. Moreover, the osteotomy inclination, torsion, and distance and the direction of eccentricity were assessed using CT reconstruction.Results: Significant differences in the operation time (p < 0.001), postoperative TPA (p < 0.05), osteotomy inclination (p < 0.05), and osteotomy torsion (p < 0.05) were observed.Conclusion: The use of TPLO surgical guide reduced the operation time and inaccurate osteotomy.Clinical Significance: The surgical technique applied with a customized 3D printing surgical guide could be used to perform osteotomy and TPA adjustment more precisely than conventional TPLO.

Evaluation of the risk of patella fracture as the result of decreasing tibial plateau angle following tibial plateau leveling osteotomy.

To evaluate the effect of postoperative tibial plateau angle (TPA) following tibial plateau leveling osteotomy (TPLO) on the risk of patella fracture during the convalescent period. Retrospective study. Fracture group: 20 stifles; reference group: 65 stifles. Medical records were reviewed for stifles with patellar fractures after a TPLO procedure (fracture group) and stifles with >180 days radiographic examination with no complications following TPLO (reference group). Stifle radiographs were masked to group and final TPA (fTPA) was measured, at the time of fracture diagnosis (fracture group) and at last follow-up (reference group), using PACS software. TPAs in the fracture and reference groups were compared using the Wilcoxon rank-sum test. Statistical significance was set at .05. Patellar fractures were diagnosed at a median of 69 days (range 31-189) after surgery. The median duration of follow-up time for the reference group was 471 days (range 180-1868). Median fTPA for the fracture group was 1.4° (range [-10.3]-7.1). Median fTPA for the reference group was 4.1° (range [-3.9]-14.1). The odds of patellar fractures increased by 21.7% (95% CI: 8.6%-35.6%) for every 1° decrease in fTPA. The risk of patella fractures increased as TPAs after TPLOs decreased. Care should be taken to avoid excessive rotation during TPLO to decrease the likelihood of postoperative patellar fractures.

Rock back phenomenon in 32 dogs that underwent tibial plateau levelling osteotomy

The aim of this study was to evaluate the postoperative temporal changes in the tibial plateau angle (TPA) after a tibial plateau levelling osteotomy (TPLO) in dogs. The TPA of thirty-two dogs were measured before surgery (TPA&lt;sub&gt;1&lt;/sub&gt;), immediately after the TPLO (TPA&lt;sub&gt;2&lt;/sub&gt;), and later at the healing of the osteotomy site (TPA&lt;sub&gt;3&lt;/sub&gt;). Three observers carried out three TPA measurements for each patient at the time of the evaluation. TPA changes were observed over the bone healing (2.05 ± 3.05°); however, no statistical significance was noted when comparing TPA&lt;sub&gt;3&lt;/sub&gt; and TPA&lt;sub&gt;1&lt;/sub&gt;. There were no statistical differences in the inter-observer measurements among TPA&lt;sub&gt;1&lt;/sub&gt;, TPA&lt;sub&gt;2&lt;/sub&gt;, and TPA&lt;sub&gt;3&lt;/sub&gt; (P &amp;gt; 0.05). The comparison between the preoperative TPA&lt;sub&gt;1&lt;/sub&gt; and the rock back showed a low positive correlation (S = 4 735.9, P = 0.471 5, r = 0.131 976 9). There was also a low positive correlation between the body weight (kg) and the change in the TPA during the bone healing (S = 4 581.8, P = 0.381, r = 0.160 234 7). Although changes in the TPA have been observed over the time of the bone healing, they were not influenced by the preoperative and postoperative TPA, or by the body weight. The magnitude of the variation in the TPA is not determined by the previous inclination or by the degree of rotation in the plateau.

Preoperative planning for tibial plateau leveling osteotomy based on proximal tibial width.

The purpose of this study was to evaluate the applicability and feasibility of a novel preoperative planning method for tibial plateau leveling osteotomy (TPLO) based on the width of the proximal tibia. All TPLO procedures were performed by the same surgeon. In preoperative planning, the width of the tibial crest to the caudal edge of the medial tibial plateau (W) was measured, and the saw blade size that was closest to the distance between the point of the cranial third W and the intercondylar tubercles was selected. The postoperative tibial plateau angle (TPA), distance of eccentricity (DOE), and minimum thickness of the tibial tuberosity remaining cranial to the osteotomy (tibial tuberosity width; TTW) were documented. Complications in the perioperative and follow-up periods were documented. Thirty-one TPLO procedures were performed in 28 dogs, including both small and large breeds. The postoperative TPA was 8.4 ± 2.0° and the DOE was 3.55 ± 2.88 mm. The ratio of the TTW to the preoperative W was 0.27 ± 0.06. There were no major complications, such as fractures of the tibial tuberosity or implant breakage. This preoperative planning method allowed appropriate planning for TPLO with a clear index that was based on the size of the tibia rather than the breed or weight of the dog. This method should be of benefit to the surgeon, whether an expert or a novice, and contribute to the success of TPLO.

Use of a Modified Tibial Plateau Levelling Osteotomy with Double Cut and Medial Crescentic Closing Wedge Osteotomy to Treat Dogs with Cranial Cruciate Ligament Rupture and Tibial Valgus Deformity.

The aim of this study was to report efficacy of a modified tibial plateau levelling osteotomy (TPLO) with double cut and medial crescentic closing wedge osteotomy (TPLO/MCCWO) to treat dogs with cranial cruciate ligament rupture and concurrent tibial valgus. This study was a cases series. Medical records of dogs that had TPLO with medial crescentic closing wedge osteotomy were reviewed. Data collected included signalment, body weight, pre- and postoperative tibial valgus angle, tibial plateau angle (TPA), surgical planning, corrective osteotomy technique, method of fixation, complications, and length of time to radiographic healing. Fifty-two surgical procedures performed in 45 dogs (7 bilateral) were included in the study. Mean age at surgery was 54 months, and body weight ranged from 5 to 63 kg (mean: 36.5 kg). Mean pre- and postoperative mechanical medial proximal tibial angle were 101° (98°-107°) and 92.80° (88°-97°) respectively. The mean pre- and postoperative TPA were 27.80° (16-35°) and 6.50° (3-11°) respectively. Intraoperative complications occurred in two stifles: in one stifle over-rotation of the proximal tibial segment resulted in a TPA of -8°, with immediate revision to a 5° TPA; in the second stifle a fissure of the lateral tibial cortex developed during insertion of a screw and required adjunctive fixation. No postoperative complications were recorded and all osteotomies healed uneventfully. Tibial plateau levelling osteotomy/medial crescentic closing wedge osteotomy is an effective treatment for dogs with cranial cruciate ligament rupture and tibial valgus allowing accurate correction of the tibial deformity with a low complication rate.

Fibular osteotomy to facilitate proximal tibial rotation during tibial plateau leveling osteotomy.

To identify factors that restrict proximal tibial rotation during tibial plateau leveling osteotomy (TPLO) and report on the outcome of concurrent fibular osteotomy (TPLO-FO). Retrospective case-control study. Dogs undergoing TPLO-FO (n = 23) and dogs undergoing routine TPLO (n = 49). Medical records and radiographs of dogs that had undergone TPLO-FO were reviewed. Data that were collected included signalment, preoperative tibial plateau angle (TPA), mechanical medial proximal tibial angle (mMPTA), postoperative and recheck TPA and mMPTA, ratio of fibular width to tibial width (FW:TW), presence of tibiofibular synostosis, tibial osteotomy location, and use of additional implants. The odds of exhibiting rotational constraints requiring FO during TPLO were 62-fold greater in dogs with tibiofibular synostosis than in dogs without synostosis. Dogs with FW:TW greater than 0.24 were 7.8-fold more likely to exhibit rotational constraints. After TPLO-FO, the postoperative increase in TPA was greater after single-plate fixation (mean, 5.4 ° ± 4.5 °) compared with fixation with 2 plates (mean, 1.4 ° ± 0.6 °). Proximal tibiofibular synostosis and a relatively wide fibula restricted tibial plateau rotation. In these dogs, concurrent fibular osteotomy allowed adequate rotation. Adjunct plate fixation limited loss of rotation after TPLO-FO. Successful TPLO relies on adequate rotation of the proximal tibial segment. Fibular osteotomy and adjunct plate fixation are recommended to achieve and maintain adequate rotation of the osteotomized tibia in dogs with rotational constraints.

Influence of methods of joint inspection during tibial plateau leveling osteotomy on the radiographic appearance of the patellar tendon.

To determine the influence of methods of joint inspection during tibial plateau leveling osteotomy (TPLO) on radiographic appearance of the patellar tendon. Retrospective study. Client-owned dogs (191) treated with TPLO (199). Data collected from medical records included signalment, weight, duration of anesthesia and surgery, preoperative and postoperative tibial plateau angle (TPA), cranial cruciate ligament status, meniscal status, and meniscal treatment. Method of joint inspection was recorded as (1) arthroscopy (AR), (2) craniomedial parapatellar arthrotomy (CrMA), or (3) caudomedial arthrotomy (CdMA). The radiographic thickness of the patellar tendon (PTT) was measured preoperatively and at 8-12 weeks postoperatively. Radiographic signs of patellar tendonitis were graded as 0-2 on the basis of the severity of changes. Thirty-nine dogs (41 stifles) underwent AR, 86 dogs (87 stifles) underwent CrMA, and 70 dogs (71 stifles) underwent CdMA. Durations of surgery (P < .001) and anesthesia (P < .001) were longer when joints were inspected by AR than by arthrotomies. PTT was greater after AR than after CrMA (P = .004) and CdMA (P < .001). The proportion of dogs with grade 1 or grade 2 PTT was greater after AR (78.04%) than after CrMA (52.87%, P = .0065) and CdMA (28.17%, P < .001). The PTT was thicker 8-12 weeks after TPLO when stifles were inspected arthroscopically rather than via arthrotomies. The method of stifle exploration during TPLO influences the postoperative radiographic appearance of the patellar tendon and may contribute to patellar tendinopathy.

Modified cranial closing wedge ostectomy in 25 dogs.

To describe the planning of a modified cranial closing wedge ostectomy (mCCWO) and determine the accuracy of execution without intraoperative jigs or alignment guides. Retrospective study. Twenty-five client-owned dogs (32 stifles) with cranial cruciate ligament disease. Medical records of dogs treated with mCCWO between July 2014 and December 2016 were reviewed. Preoperative, postoperative, and 8-week-recheck radiographs were reviewed to measure changes in the conformation of the proximal tibia. The accuracy of execution was assessed by comparing planned and actual postoperative tibial plateau angle (TPA) and the lengths of bone contact along osteotomy lines. Radiographic healing and clinical outcome were subjectively evaluated 8 weeks after surgery. Preoperative planning of mCCWO decreased the cranial wedge length by a mean of 23% compared with the traditional CCWO planning. Mean TPA decreased from 40.69 ° (range 28-63) to 6.94 ° (range 2-20) after surgery (P < .001). Mean tibial length decreased by 0.5 mm (±0.16, P = .003), from 138 mm (range 65-267) to 137.5 mm (range 65-265) after mCCWO. The tibial long axis (TLA) shifted by a mean of 3.47 ° (range 0-10). Planned and actual postoperative TPA differed by -0.66 ° (±0.47, P = .034). The proximal and distal apposing osteotomies differed in length by 1.81 mm (±0.35). No bone healing complications or implant failures were diagnosed, and all dogs returned to subjectively satisfactory function by 8 weeks after surgery. The preoperative planning and methods of execution of the mCCWO resulted in differences in target TPA and postoperative TPA, differences in lengths of proximal and distal osteotomies, and tibial shortening that did not appear clinically significant in this study. mCCWO can be planned and accurately executed without consideration of TLA shift or the intraoperative use of alignment guides or jigs.

Effect of Tibial Plateau Levelling Osteotomy on Cranial Tibial Subluxation in the Feline Cranial Cruciate Deficient Stifle Joint: An Ex Vivo Experimental Study.

This study evaluated the effects of tibial plateau levelling osteotomy on cranial tibial subluxation and tibial rotation angle in a model of feline cranial cruciate ligament deficient stifle joint. Quadriceps and gastrocnemius muscles were simulated with cables, turnbuckles and a spring in an ex vivo limb model. Cranial tibial subluxation and tibial rotation angle were measured radiographically before and after cranial cruciate ligament section, and after tibial plateau levelling osteotomy, at postoperative tibial plateau angles of +5°, 0° and -5°. Cranial tibial subluxation and tibial rotation angle were not significantly altered after tibial plateau levelling osteotomy with a tibial plateau angle of +5°. Additional rotation of the tibial plateau to a tibial plateau angle of 0° and -5° had no significant effect on cranial tibial subluxation and tibial rotation angle, although 2 out of 10 specimens were stabilized by a postoperative tibial plateau angle of -5°. No stabilization of the cranial cruciate ligament deficient stifle was observed in this model of the feline stifle, after tibial plateau levelling osteotomy. Given that stabilization of the cranial cruciate ligament deficient stifle was not obtained in this model, simple transposition of the tibial plateau levelling osteotomy technique from the dog to the cat may not be appropriate.

A novel jig arm to measure tibial plateau angle during tibial plateau leveling osteotomy.

To determine the ability of a novel device attached to the proximal tibial plateau leveling osteotomy (TPLO) jig pin to accurately predict intraoperative change in tibial plateau angle (TPA). In vitro cadaveric study. Left hindlimbs of adult dogs (n = 9). A modified Slocum tibial plateau leveling (TPL) jig with the Rotational Osteotomy Measuring Arm (ROMA) was placed on the tibia and a radial TPLO osteotomy was performed. Based on preoperative radiographic TPA measurements, the proximal segment was rotated using the traditional method of marking points on the osteotomy a specified distance apart. After rotation, the predicted TPA was recorded based on the ROMA. Postoperative TPA was measured on radiographs. The ability of the ROMA to predict postoperative TPA was compared to that of the traditional method. The average final TPA achieved with the traditional method was 6.4° (range, 3.0-10.0°). The ROMA predicted a final TPA of 5.8° (range, 3.8-10.1°). No significant difference was found between the TPA predicted based on the traditional method and ROMA method. The ROMA may be an alternative to the traditional method of measuring proximal segment rotation during TPLO procedure. Performing a TPLO with the ROMA may accurately predict the postoperative TPA while eliminating the need for measuring chord length, making reference marks, or referencing TPA charts for various osteotomy blade sizes.

Sagittal accuracy of tibial osteotomy position during in vivo tibial plateau levelling osteotomy performed without an alignment jig and cutting guide.

To assess the accuracy of tibial osteotomy location for tibial plateau levelling osteotomy (TPLO) in the sagittal plane and its effect on the postoperative tibial plateau angle (TPA), when performed without an alignment jig and saw guide. Also, to document the improvement gained with experience. Medical records and stifle radiographs of dogs undergoing TPLO, without the use of an alignment jig and saw guide, by one surgeon were reviewed (2010-2014). Postoperative radiographs were reviewed to record the distance and direction of eccentricity. Postoperative TPA was also recorded. In a series of 401 TPLO procedures, 231 met the inclusion criteria. The absolute distance of eccentricity (DOE) for all dogs was 3.0 ± 1.6 mm. When evaluating surgical experience, the DOE for the final 77 cases (2.72 ± 1.43 mm), the middle 77 cases (3.18 ± 1.49 mm), and the first 77 cases (3.24 ± 1.7 mm) were not significantly different (p = 0.07157). There was a very weak correlation between DOE and postoperative TPA (R = 0.029). The location of the tibial osteotomy when performing TPLO without an alignment jig and saw guide compared favourably with previously documented use of an alignment jig and saw guide. Whilst the location of the tibial osteotomy has a theoretical impact on the postoperative TPA, other factors appear to be of greater importance. Surgeon experience did not result in significant improvement in accuracy up to 231 procedures.

Outcome of Tibial Closing Wedge Osteotomy in 55 Cranial Cruciate Ligament-Deficient Stifles of Small Dogs (

To describe the outcome of cranial closing wedge osteotomy (CWO) of the tibia for treatment of cranial cruciate ligament (CrCL)-deficient stifles in dogs with a body weight of <15 kg. Retrospective case series. Forty-five client-owned dogs (n=55 stifles). Medical records (2005-2014), radiographs, and owner questionnaire were used to identify the surgical procedure performed, associated complications and outcome in 45 dogs undergoing CWO in 55 stifles. Data for 55 stifles from 45 dogs were included. Bichon Frise was the most frequent dog breed (n=11). Mean pre- and postoperative tibial plateau angle (TPA) were 36.3° (95% CI 35.1-37.5) and 7.5° (95% CI 6.7-8.2), respectively. Pin and tension bands were placed in 38/55 stifles (69%). The most frequent complication at short-term follow-up (2 weeks) was incisional complications in 8 stifles; all resolved with systemic antibiotic administration alone. Data were available for all stifles at 8 week follow-up with an overall complication occurrence in 16/55 stifles (28%); 1 dog required revision surgery. Tibial osteotomy healing was evident on radiographs at 8 weeks postoperative in 53 stifles (96%), considered complete in 27 stifles, and good in 26 stifles. Follow-up owner questionnaire was available for 36 dogs at a mean of 24 months and 34/36 owners (94%) were satisfied with the procedure and considered their dog had a good quality of life with minimal long-term complications. Dogs with a body weight <15 kg undergoing CWO for treatment of a CrCL-deficient stifle had a good outcome based on clinical status, radiographic evaluation, and owner questionnaire.