Risk Factors for Fibular Fracture after TPLO

Prospective evaluation of the surgical stabilization and outcome of canine tibial plateau fractures in three cases

OBJECTIVE

To report the surgical approaches and stabilization of lateral and medial tibial plateau fractures (TPF), as well as the long-term outcome following repair.

STUDY DESIGN

Prospective series of three client-owned dogs.

ANIMALS

Three dogs.

METHODS

For the two lateral TPF cases (Unger type 41-B1), the surgical approach included separation of the lateral collateral ligament and long digital extensor tendon. The lateral meniscus was elevated to allow visualization of the tibial surface and assess fracture reduction. The first case was repaired using two 2.0 mm lag screws (with washers). The second case sustained a lateral TPF, fibular fracture and concurrent tubercle of Gerdy fracture. Both tibial fractures were stabilized using two 2.0 mm lag screws with washers and two 0.9 mm Kirschner wires (K-wires). A third case, diagnosed with an Unger type 41-B2 medial TPF, was treated using 0.9 mm K-wires and 22-gauge tension band.

RESULTS

There were no major complications noted. One minor complication occurred (screw yield two weeks postoperatively). By 8 weeks, all patients reached clinical union with good limb function. Owners were contacted 9-36 months postoperatively. LOAD scores and examinations were performed for two of three patients; the third patient was not contactable after relocating out of state. Both cases with completed questionnaires had a LOAD score of 5/52.

CONCLUSION

Tibial plateau fractures are rare in canine patients. While challenging, they can be successfully managed using a combination of lag screws, K-wires, and tension band.

CLINICAL SIGNIFICANCE

Surgical stabilization of TPF is feasible and may reduce the risk of meniscal injury.

Outcome in 12 Dogs with Chronic Radiographic Cranial Tibial Subluxation after Tibial Plateau Leveling Osteotomy (2019-2021)

Objective

The objective of this study was to examine outcomes in dogs with cruciate ligament rupture (CR) that had chronic radiographic cranial tibial subluxation at the time of osteotomy healing after tibial plateau leveling osteotomy (TPLO). Study Design. Retrospective case analysis of 12 dogs with prospective follow-up. Four of the 12 dogs were prospectively studied 12-24 months after surgery to assess long-term radiographic and clinical outcomes.

Results

Three of the 4 dogs showed improvement in radiographic cranial tibial subluxation at long-term follow-up. In the other dog, minimally improved cranial tibial subluxation was associated with severe lameness. At long-term follow-up, gait analysis in 3 dogs with improved subluxation showed the symmetry of weight-bearing within 10% for peak vertical force, and no clinically lameness. Preoperative tibial plateau angle (TPA) and radiographic osteoarthritis in dogs with prospective follow-up and all dogs treated with TPLO surgery in the study period were not significantly different.

Conclusion

Dogs with chronic radiographic cranial tibial subluxation are acceptable candidates for TPLO. Radiographic improvement in stifle reduction may take more than 10 weeks. The dog with long-term persistent subluxation also had a higher TPA over time, suggestive of ineffective surgical correction with TPLO and treatment failure.

Tibial Plateau Leveling Osteotomy in small and large breed dogs: a comparative retrospective study of complications and outcomes

OBJECTIVE

To compare complication rates and outcomes of small and large breed dogs that had locking plate Tibial Plateau Leveling Osteotomy (TPLO) performed due to cranial cruciate ligament disease during the same time period at a single institution and identify potential influencing factors.

MATERIAL AND METHODS

136 cases with TPLO performed at a single institution between January 2013 and December 2015 were retrospectively reviewed. Dogs were grouped by plate sizes (2.0, 2.4, 2.7, 3.5 and 3.5 broad) and by small breeds (2.0-2.7 plate sizes) and large breeds (3.5 plates). Potential influencing factors on lameness and complications were recorded from the database and measured on radiographs and statistically compared.

RESULTS

Small dogs experienced fewer complications than large dogs (10% vs. 22%) and not a single major complication. Small dogs were significantly less lame at recheck and at long-term follow-up. Progression of bone healing had an influence on the lameness grade of dogs at recheck after TPLO. Distance of the most proximal screw from the joint was identified as a risk factor for implant failure. The width of the patella ligament correlated with body weight and uniformly increased 2.4 times after TPLO.

CONCLUSIONS

TPLO in small breed dogs has a lower overall complication rate than in large breed dogs. The TPLO plate should always be placed as close to the joint as possible to reduce the risk of implant failure.

CLINICAL RELEVANCE

TPLO can be recommended as treatment for cranial cruciate ligament rupture (CCLR) in dogs of all sizes.

Evaluation of the clinical value of routine radiographic examination during convalescence for tibial plateau-leveling osteotomy

OBJECTIVE

To determine how frequently routine follow-up radiographic findings would result in a change to the postoperative plan following tibial plateau-leveling osteotomy (TPLO) in dogs.

STUDY DESIGN

Retrospective study SAMPLE POPULATION: Short-term group: 100 cases; intermediate-term group: 50 cases.

METHODS

Medical records of 100 consecutive cases meeting the inclusion criteria were reviewed (the short-term group). The cases had no owner-perceived issues and underwent routinely prescribed radiographic follow up between 40 and 60 postoperative days after TPLO performed by one experienced surgeon. Complications identified on physical examination (PE) and radiographic examination (RE) were recorded, along with any changes to the postoperative plan. Medical records of 50 consecutive cases that had short-term and intermediate-term (≥180 days) REs and PEs were reviewed similarly (intermediate-term group).

RESULTS

Fifty-one cases in the short-term group had no complications on PE or RE. Forty-nine dogs were diagnosed with minor complications (patellar ligament desmitis, patella or fibula fracture, gait abnormalities): 42 on RE only; 6 on PE and RE; 1 on PE only. Exercise restriction was extended for 2 weeks in 2 cases with radiographic patellar ligament desmitis. Two cases in the intermediate-term group had minor complications at intermediate-term RE. No new PE or RE complications developed between short-term and intermediate-term evaluations.

CONCLUSION

At routine rechecks of dogs with no owner-perceived issues after TPLO, 49% had minor complications but only 2% were deemed significant enough to alter patient management. The likelihood of new radiographic complications developing after short-term evaluation is low.

CLINICAL SIGNIFICANCE

Routine radiographic recheck examinations rarely altered the postoperative plan in TPLO cases with unremarkable clinical recoveries.

The epidemiology of cruciate ligament rupture in an insured Swedish dog population

Cruciate ligament rupture (CLR) is a common orthopedic disorder in dogs. The study objectives were to evaluate incidence rate (IR), cause-specific mortality rate (CSMR) and risk factors for CLR in insured dogs. A single cohort study of dogs insured in Agria Pet Insurance in Sweden (2011–2016) was performed. Age at diagnosis, IR, CSMR and relative risk (RR) for CLR was calculated overall and per breed. The cohort included just over 600,000 dogs. The IR of CLR was 23.8 (95% confidence interval, 23.1–24.6) cases per 10,000 DYAR. The breeds with highest RR of CLR were Boerboel and Dogo Canario, while the breeds with lowest RR were Standard Dachshund and Miniature Pinscher. Dogue de Bordeaux had highest RR of euthanasia due to CLR. The median age at veterinary care claim for CLR was 7.1 (range 0.3–16.0) years and 6.6 (0.3–12) years at life insurance settlement. Large and giant breeds were generally diagnosed and euthanized due to CLR at a younger age compared to smaller breeds. The majority of the breeds with increased RR of CLR diagnosis and CLR-related euthanasia were large or giant. A pattern of increasing size and decreasing age at diagnosis/CLR-related euthanasia was observed.

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

OBJECTIVE

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.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Fracture group: 20 stifles; reference group: 65 stifles.

METHODS

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.

RESULTS

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.

CONCLUSION

The risk of patella fractures increased as TPAs after TPLOs decreased.

CLINICAL SIGNIFICANCE

Care should be taken to avoid excessive rotation during TPLO to decrease the likelihood of postoperative patellar fractures.

Risk factors for severe postoperative complications in dogs with cranial cruciate ligament disease - A survival analysis

OBJECTIVE

To analyze the effect of surgical technique and other risk factors on severe postoperative complications in dogs with cranial cruciate ligament disease (CCLD).

MATERIALS AND METHODS

A cohort study of 255 dogs (287 stifles) surgically treated for CCLD at two veterinary university hospitals (2011-2016) was performed. The electronic medical records were reviewed and dog owners and referring veterinarians contacted for additional information. The complications were classified as minor, major and catastrophic, where major and catastrophic were considered severe. A multivariable Cox proportional hazards model was applied to assess risk factors for severe postoperative complications.

RESULTS

Three surgical techniques were used; lateral fabellotibial suture (LFS, 141 stifles), tibial plateau leveling osteotomy (TPLO, 77 stifles) and tibial tuberosity advancement (TTA, 69 stifles). The most common severe postoperative complications were surgical site infections or complications related to the surgical implant. Severe postoperative complications occurred in 31 % of the stifles treated with TPLO, 22 % of the stifles treated with LFS and 25 % of the stifles treated with TTA. The multivariable Cox proportional hazards model identified surgical technique (p = 0.0258) as a risk factor for severe postoperative complications; TPLO had a significantly lower hazard than LFS (hazard ratio (HR) = 0.37, p = 0.007) when controlling for body weight and age, which also were identified as risk factors (HR = 1.05, p < 0.001 and HR = 0.91, p = 0.047, respectively).

CONCLUSION AND CLINICAL RELEVANCE

Although TPLO procedures had the highest occurrence of severe postoperative complications, the hazard was lower than for LFS after adjusting for body weight and age. This implies that it is important to consider potential effect-modifiers when comparing postoperative complications after CCLD surgery.

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

OBJECTIVE

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).

STUDY DESIGN

Retrospective case-control study.

ANIMALS

Dogs undergoing TPLO-FO (n = 23) and dogs undergoing routine TPLO (n = 49).

METHODS

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.

RESULTS

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 °).

CONCLUSION

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.

CLINICAL SIGNIFICANCE

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.

Contribution of antirotational pins and an intact fibula to the ex vivo compressive strength of four tibial plateau leveling osteotomy constructs

OBJECTIVE To assess the contribution of antirotational pins (ARPs) and an intact fibula to the compressive strength of 4 tibial plateau leveling osteotomy (TPLO) constructs (bone and implants). SAMPLE 20 hind limbs from 10 canine cadavers. PROCEDURES Each hind limb was assigned to 1 of 4 TPLO constructs (construct in which the ARP was removed, constructs in which 1 or 2 ARPs were left in place, and construct in which the ARP was removed and the fibula was cut). Following TPLO completion, all limbs underwent mechanical testing that included 10,000 cycles of cyclic axial compression followed by testing to failure at a displacement rate of 1 mm/s. Displacement during cyclic testing; load generated at 0.5, 1.0, and 3.0 mm of displacement; ultimate load; and failure type were recorded for each limb. Mean values were compared among the groups. RESULTS None of the specimens failed during cyclic testing. None of the variables assessed during mechanical testing differed significantly among the 4 groups. During testing to failure, the majority (17/20) of specimens failed as the result of a long oblique fracture through the first screw hole in the distal segment. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the axial compressive strength and stiffness of a TPLO construct were not significantly affected by the addition of 1 or 2 ARPs or the presence of an intact fibula. These findings appear to support removal of ARPs during uncomplicated TPLOs, but further research is warranted to assess the effect of ARP removal on bone healing and complication rates.

Complications of tibial plateau levelling osteotomy in dogs

The tibial plateau levelling osteotomy (TPLO) is one of the most common surgical procedures used to treat cranial cruciate ligament disease in dogs. Complications occurring during or after TPLO can range in severity from swelling and bruising to fracture and osteomyelitis. Ten to 34% of TPLO surgical procedures are reported to experience a complication and approximately two to four percent require revision surgery to address a complication. Although the risk factors for many complications have not been fully assessed, the best available evidence suggests that complications of TPLO can be reduced with increased surgeon experience, careful surgical planning, and accurate execution of the surgical procedure. Identification of known or suspected risk factors and intraoperative technical errors allow subsequent action to be taken that is aimed at decreasing postoperative morbidity. There is a need for prospective studies with consistent data reporting in order to fully reveal the incidence risk factors for complications associated with TPLO.

Tibial plateau levelling osteotomy in eleven cats with cranial cruciate ligament rupture

OBJECTIVE

To report the surgical procedure, intra- and postoperative complications, and short-term follow-up of tibial plateau levelling osteotomy (TPLO) in feline patients with cranial cruciate ligament (CrCL) rupture using a 2.0 or 2.4 mm Synthes^® TPLO plate.

STUDY DESIGN

Prospective study.

MATERIAL AND METHODS

Eleven cats with a CrCL rupture were included in the study. Inspection of intra-articular structures was carried out via arthroscopy or arthrotomy. Each patient was re-examined one and 10 days after surgery. Orthopaedic examination and follow-up radiographs were obtained four to 12 weeks postoperatively.

RESULTS

Two meniscopathies and one partial CrCL rupture were detected. Minor intra-operative complications occurred in five cats (suboptimal positioning of the plate [n = 3], proximal fibular fracture [n = 1], a visible osteotomy gap [n = 1]). Postoperatively, minor complications were detected in three cats (mild patellar desmitis [n = 2], superficial wound infection [n = 1]). No additional surgical reintervention, graded as major complication, was necessary. Four to eight weeks postoperatively, all cats showed no to mild intermittent lameness. Complete bone union was apparent within four to 12 weeks. Owners reported a high level of comfort and mobility during the last follow-up.

CONCLUSION

The preliminary results of this study support the use of TPLO in cats, but larger case numbers are needed to evaluate its practicability, as well as long-term outcome (>1 year), especially evaluating the development and the clinical relevance of osteoarthritis.

Accuracy of three pre- and intra-operative measurement techniques for osteotomy positioning in the tibial plateau levelling procedure

OBJECTIVES

To prospectively compare the accuracy of three preoperative measurement techniques in tibial plateau levelling osteotomy (TPLO) planning.

METHODS

Fifty-nine dogs were randomly assigned to one of three measurement techniques; A, B or C. Surgeons measured the intended osteotomy location on preoperative radiographs according to the assigned technique. Measurements were used intra-operatively during osteotomy placement. Postoperative measurements were made by a single blinded observer and compared to preoperative measurements.

RESULTS

Fifty-one dogs were included for final statistical analysis. The mean absolute differences between pre- and postoperative measurements was 1.72 mm ± 0.958, 1.79 mm ± 1.010, and 3.56 mm ± 1.839, for techniques A, B and C, respectively. No significant differences were identified for patient age, gender, limb or surgeon. Techniques A and B were not significantly different (p = 0.8799). Techniques A and B were significantly more accurate than C (p = 0.0001 and p = 0.0003, respectively). Weight was significantly different among the groups (p = 0.047) but the statistical results did not change when an adjustment was made for bodyweight (p = 0.4971, p <0.001 and p = 0.0007, respectively).

CLINICAL SIGNIFICANCE

Preoperative measuring for planning a TPLO osteotomy is recommended. Techniques A and B in the current study were clinically practical and significantly more accurate compared to technique C.

Osteosarcoma following tibial plateau leveling osteotomy in dogs: 29 cases (1997-2011)

OBJECTIVE

To determine the signalment, tibial plateau leveling osteotomy (TPLO) plate type, clinical staging information, treatment, and oncological outcome in dogs that developed osteosarcoma at the proximal aspect of the tibia following TPLO and to calculate the interval between TPLO and osteosarcoma diagnosis.

DESIGN

Multi-institutional retrospective case series.

ANIMALS

29 dogs.

PROCEDURES

Medical records from 8 participating institutions were searched for dogs that developed osteosarcoma (confirmed through cytologic or histologic evaluation) at previous TPLO sites. Signalment, TPLO details, staging tests, treatment data, and outcome information were recorded. Descriptive statistics were calculated, and disease-free intervals and survival times were evaluated by means of Kaplan-Meier analysis.

RESULTS

29 dogs met the inclusion criteria. The mean age was 9.2 years and mean weight was 45.1 kg (99.2 lb) at the time of osteosarcoma diagnosis. Most dogs had swelling over the proximal aspect of the tibia (17/21) and lameness of the affected limb (28/29). The mean interval between TPLO and osteosarcoma diagnosis was 5.3 years. One type of cast stainless steel TPLO plate was used in most (18) dogs; the remaining dogs had received plates of wrought stainless steel (n = 4) or unrecorded type (7). Twenty-three of 29 dogs underwent treatment for osteosarcoma. Median survival time for 10 dogs that underwent amputation of the affected limb and received ≥ 1 chemotherapeutic treatment was 313 days.

CONCLUSIONS AND CLINICAL RELEVANCE

Results supported that osteosarcoma should be a differential diagnosis for dogs with a history of TPLO that later develop lameness and swelling at the previous surgical site. Oncological outcome following amputation and chemotherapy appeared to be similar to outcomes previously reported for dogs with appendicular osteosarcoma.

In vitro incidence of fibular penetration with and without the use of a jig during tibial plateau leveling osteotomy

OBJECTIVE

To determine the incidence of fibular penetration during placement of the Synthes® locking TPLO plate with and without the use of a jig.

STUDY DESIGN

Cadaveric, experimental study.

SAMPLE POPULATION

Cadaveric paired pelvic limbs (n = 8) from skeletally mature dogs.

METHODS

Limbs were assigned to 1 of 2 groups (jig-less-TPLO = no jig used; jig-TPLO = jig used). Synthes® locking TPLO plates were applied using proximal screws of excessive length to facilitate identification of fibular penetration. Screw tip locations were identified by dissection and frequency of fibular penetration was compared between groups.

RESULTS

None of the jig-TPLO limbs and 6 (75%) of jig-less-TPLO limbs had fibular penetration, a difference that was statistically significant. Fibular penetration was most frequently associated with the most proximal screw.

CONCLUSIONS

A significantly higher incidence of fibular penetration occurs when Synthes® locking TPLO is performed without use of a jig.

A pitfall on postoperative radiographs in dogs after tibial plateau leveling osteotomy

OBJECTIVE

To identify the cause of an occasional radiolucent line in the tibia on postoperative radiographs after tibial plateau leveling osteotomy (TPLO) in dogs.

STUDY DESIGN

Retrospective case series and ex vivo experiment.

SAMPLE POPULATION

Dogs (n = 80; 87 stifles) with cranial cruciate ligament (CCL) rupture that had TPLO; and 4 canine tibia specimens.

METHODS

Medical records (2007-2010) and radiographs of dogs that had TPLO were reviewed and examined for presence of a radiolucent line on postoperative radiographs. The TPLO procedure was reproduced ex vivo to determine the origin of this line by use of metallic wires to identify bone contours.

RESULTS

A curvilinear radiolucent line was visible in 14 (16%) tibias and was 5.4 times more likely to be visible with lateral misalignment of the tibial diaphysis relative to the plateau and 2.6 times more likely visible on caudocranial radiographs with the stifle in outward rotation. Fracture complication rate was higher in dogs with this radiolucent line (P = .02) and with lateral misalignment of the tibial diaphysis relative to the plateau (risk ratio, 3.8). The line could be reproduced ex vivo and caused by superimposition of the craniomedial border of osteotomy with the tibial plateau.

CONCLUSIONS

The radiolucent line was a spurious fracture line created by the medial margin of the tibial osteotomy and confounding factors such as tibial misalignment may explain the apparently associated higher complication rate.