Tibial Tuberosity Advancement In Dogs Research Articles

Comparison of Two Preoperative Radiographic Methods for Assessing Tibial Tuberosity Advancement to Achieve a Postoperative Patella Tendon Angle of 90° in Dogs.

Previous studies have suggested that the preoperative methods used to plan tibial tuberosity advancement in dogs may result in under-advancement. Therefore, this cadaveric study compared the effectiveness of the common tangent method and the tibial-anatomy-based method for achieving a target patellar tendon angle (PTA) of 90° after the modified Maquet procedure. Twenty stifle joints of mesomorphic dogs were randomly assigned to the two measurement methods. Radiographs taken in the mediolateral projection were used to measure tibial tuberosity advancement, and the wedge size was selected accordingly. For each surgical procedure, a custom-made three-dimensional wedge matched to an OrthoFoam wedge was used as a spacer. Postoperative radiographs were used to measure the PTA and to evaluate the position of the wedge. The measured advancement was not significantly different between the two methods. For 60% of the cases, the advancement measured using the common tangent method was <5.3 mm and the wedge size was increased to match that of commercially available wedges. Consequently, there was a significant difference between the measurements and wedges selected between the two procedures. The postoperative PTA did not differ significantly between the two methods and was 90° ± 5° in 80% of the stifles. The position of the wedge relative to the osteotomy was not significantly different between the methods. In conclusion, the advancement determined using the tibial-anatomy-based method was generally consistent with the size of commercially available wedges, and the method yielded a mean postoperative PTA of 90°.

Role of Tibial Tuberosity Fracture/Fissure through the Maquet Hole in Stifle Osteoarthritis after Porous Tibial Tuberosity Advancement in Dogs at Mid-Term Follow-Up.

Tibial tuberosity advancement (TTA) is used to treat cranial cruciate ligament rupture of the stifle joint in dogs. Tibial tuberosity fracture/fissure is a complication of TTA that may have a favorable prognosis. The aim of this study was to detect how tibial tuberosity fracture/fissure through the Maquet hole worsens the progression of osteoarthritis (OA) in the stifle joint of dogs treated with porous TTA. Seventeen cases were included in the study, divided into two groups. The first group (n = 10) included subjects that had tibial tuberosity fracture/fissure through the Maquet, and the second group included subjects that had no complications (n = 7). Both groups showed significant progression compared to OA at 3 months after surgery. We observed that at T0, the control group showed a higher level of OA. For this reason, we normalized the OA scores, evaluating the percentage difference from T0 and T1. We verified that there were no statistically significant differences between the two groups. The results confirm that OA progression in subjects undergoing TTA was not significantly influenced by fracture/fissure of the tibial tuberosity through the Maquet hole. Therefore, fracture fissure through the Maquet hole should be considered as a common minor complication during TTA.

Biological response to an experimental implant for tibial tuberosity advancement in dogs: A pre-clinical study

In this study, we propose a novel bioresorbable bioactive implant for tibial tuberosity advancement (TTA). The implant consists of a gradually resorbing load-bearing shell which encompasses rapidly resorbing small casings loaded with silica-based bioactive glass (BG) particulates which promote bone formation and reduce the risk of infection. The shell and the casings are manufactured by 3D printing from two medical grade bioresorbable polymers (a polyglycolide/lactide based and a polydioxanone based) that have different degradation rates. The casings are expected to resorb within days after surgery to expose the BG particulates while the shell would retain the load-bearing properties of the implant for the time required by bone healing. Unlike the currently used metallic devices, the novel implant is resorbed and excreted from the body once its purpose is fulfilled.This study presents a logical progression from the in vitro characterisation of the materials and implants to the in vivo investigation of the experimental implants. This included mechanical testing of the materials, finite element analysis of a preliminary design of the novel TTA implant, assessment of the degradation behaviour of the polymers and the ion exchange of BG in simulated body fluid, and investigation of the biological response to the novel implants after implantation in rabbits.The osteointegration of the novel implants was comparable to the osteointegration of Ti6Al4V implants in the control group; the biological efficacy and safety were confirmed. The biological response was in line with the expectations. The proof of concept for the novel TTA implants was demonstrated.

Mesenchymal stem cells in osteotomy repair after tibial tuberosity advancement in dogs with cranial cruciate ligament injury

BackgroundThe cranial cruciate ligament rupture (CCLR) is the most commonly encountered orthopedic condition in dogs. Among the various techniques to treat this condition, tibial tuberosity advancement (TTA) has been used to obtain rapid recovery of the affected knee. The objective of this study was to evaluate the viability of the use of mesenchymal stem cells (MSC) implanted in the osteotomy site obtained by TTA in nine dogs diagnosed with CCLR.MethodsThe MSC were isolated from the adipose tissue of the dogs and cultured for eight days, the animals were divided into two groups. Animals from the treated group (GT) received cell transport medium containing about 1.5 millions MSC, and the animals from the control group (GC) received only the cell transport medium. The study was performed in a double-blind manner using radiographs acquired on days 15, 30, 60 and 120 after the procedure. Evaluations of the density of the trabecular bone were performed using image analysis software. The results were subjected to descriptive statistical analysis, followed by the normality test, Chi-square test, Mann-Whitney test and Tukey’s multiple comparison test for p ≤ 0.05.ResultsAfter 30 days of the procedure, the animals of the GT presented an ossification mean 36.45% greater (p ≤ 0.033) than the GC, and there were no statistical differences for the other periods.ConclusionsDespite the total bone ossification within the expected period, there was no minimization of the estimated recovery time with the application of MSC, and inflammatory factors should be considered for reassessment of the therapeutic intervention time.

Comparison of bone healing, as assessed by computed tomography, following tibial tuberosity advancement in dogs with and without autogenous cancellous bone grafts

AIMS: To objectively compare measures of bone healing, using computed tomography (CT) in dogs following bilateral tibial tuberosity advancement (TTA), between tibiae treated with and without autogenous cancellous bone grafts.METHODS: Ten dogs with bilateral cranial cruciate ligament disease requiring surgical stabilisation were prospectively recruited to undergo single-session bilateral TTA, with only one, randomly assigned, tibia receiving bone graft in the osteotomy deficit. Bone healing at the osteotomy site was assessed using CT performed 38–70 days post-operatively. CT images were evaluated using both objective measurements of osseous bridging and subjective evaluation by six radiologists. Repeated measures ANOVA was used to compare the objective outcomes between the grafted and non-grafted tibiae.RESULTS: The mean percentage of the osteotomy deficit bridged at the lateral cortex was greater in grafted (77.6, SD 35.2%) compared to non-grafted (63.0, SD 36.5%) tibiae (p=0.001), but did not differ at the medial cortex (p=0.1). The mean minimum callus width was greater in grafted (7.2, SD 3.3 mm) compared to non-grafted (3.6, SD 2.9 mm) tibiae (p<0.001). There was no difference in mean attenuation (measured in Hounsfield units) of the callus between grafted and non-grafted tibiae (p=0.5). The grafted tibia was deemed to have superior bone healing in 50/60 subjective assessments made by radiologists.CONCLUSIONS: Superior osseous bridging was detected by CT analysis following TTA using autogenous cancellous bone grafts compared with no graft. This was shown by greater bridging percentage at the lateral cortex and formation of a broader callus. Qualitative assessments made by six radiologists also supported the conclusion that bone healing was improved by use of autogenous cancellous bone graft. CT was a useful method for assessing evidence of bone healing following TTA.CLINICAL RELEVANCE: These findings justify the application of autogenous cancellous bone graft to augment healing following TTA in dogs.

The effect of cancellous bone grafts on time to consolidation at osteotomy site following tibial tuberosity advancement in dogs

Rupture of the cranial cruciate ligament is the main cause of lameness in dogs. Several surgical techniques are used as a treatment, especially osteotomies, as the tibial tuberosity advancement (TTA). Recently new research are being conducted investigating ways to reduce bone healing time. Cancellous bone grafting is considered to be the gold standard method to speed healing due to its osteoinductive and osteoconductive properties. The aim of this study was to evaluate the effect of cancellous gone grafts on the time taken for consolidation at the osteotomy site in dogs undergoing TTA surgery. TTA surgery was performed in 19 stifles in which there was rupture of the cranial cruciate ligament and a tibial plateau angle less than 27 degrees. The cases were divided into two groups: dogs in the control group (C) had TTA only and for those in the study group (E) TTA was complimented with a cancellous bone graft. Serial radiographs were evaluated at 21 day intervals post-surgery and consolidation was confirmed by visual inspection by three observers (two radiologists and an orthopedic surgeon). There was no difference in consolidation time between Groups C and E. The addition of cancellous bone grafting to the osteotomy did not influence time to consolidation in dogs undergoing TTA surgery.

Radiographic evaluation and comparison of the patellar ligament following tibial plateau leveling osteotomy and tibial tuberosity advancement in dogs: 106 cases (2009-2012).

OBJECTIVE To radiographically evaluate and compare changes in the patellar ligament of dogs following tibial plateau leveling osteotomy (TPLO) and tibial tuberosity advancement (TTA). DESIGN Retrospective case series. ANIMALS 106 dogs that underwent TPLO (n = 59) or TTA (n = 47) for unilateral rupture of the cranial cruciate ligament at a private veterinary hospital from August 2009 through September 2012. PROCEDURES Medical records were reviewed to collect information on dog signalment, surgical procedure, whether arthrotomy had been performed, pre- and postoperative measurements of patellar ligament angle (PLA) and tibial plateau angle (TPA), and preoperative and follow-up measurements of patellar ligament thickness. RESULTS For dogs that underwent TTA, thickening of the distal portion of the patellar ligament was identified radiographically in 43 (92%) dogs at the first follow-up examination and 36 (77%) at the second follow-up examination. For dogs that underwent TPLO, these numbers were 57 (97%) and 54 (92%), respectively. A significant decrease in patellar ligament thickness was identified between the first and second follow-up examinations for TTA but not TPLO. Mean ± SD PLA following TTA was 89.46 ± 5.54°, representing a mean difference from the preoperative PLA of 11.86 ± 5.3°; following TPLO, mean TPA was 12.61 ± 4.03°, representing a mean difference from the preoperative TPA of 16.74 ± 7.13°. CONCLUSIONS AND CLINICAL RELEVANCE Patellar ligament thickening occurred following TPLO and TTA in dogs. The clinical relevance of this thickening remains unknown.

Risk factors for tibial tuberosity fracture after tibial tuberosity advancement in dogs.

To retrospectively identify factors that predispose to tibial tuberosity (TT) fracture after tibial tuberosity advancement (TTA) in dogs. The medical records and radiographs of a group of control dogs (n = 212) that had TTA surgery (n = 241 procedures) and did not sustain a fracture between 2008 and 2013, and those of 12 dogs that did sustain a fracture (n = 13 procedures) between 2008 and 2013 at two veterinary teaching hospitals were evaluated to determine the effect of signalment, body weight and surgical inaccuracies on TT fracture. Multivariable logistic regression was performed with the occurrence of TT fracture as the outcome variable of interest. Signalment and body weight were not found to be associated with TT fracture. Of the surgical inaccuracies, osteotomy shape (p = 0.003), plate position (p = 0.009), and cage position (p = 0.039) were factors significantly associated with TT fracture. This study provides data to support the hypothesis that poor plate position, poor cage position, and narrow distal osteotomy width are associated with TT fracture after TTA. We conclude that it is of paramount importance to pay careful attention to surgical technique in order to reduce this risk.

Effect of tibial subluxation on the measurements for tibial tuberosity advancement in dogs with cranial cruciate ligament deficiency. An ex vivo study.

The main objectives were to evaluate the impact of femorotibial subluxation on the preoperative measurements for tibial tuberosity advancement (TTA) by defining radiographic landmarks and testing the repeatability for assessing cranial tibial subluxation (CTS). Also, we aimed at developing a formula to calculate the necessary adjustment in measurement of TTA in stifles with CTS. Forty stifles were used to examine the influence of CTS on preoperative TTA measurements before and after transection of the cranial cruciate ligament. Mediolateral radiographs were obtained and measurements performed by three investigators. The observed variabilities were assessed by inter- and intra-observer differences. Measurements of CTS and preoperative TTA showed a good to excellent inter- and intra-observer correlation. We found a significant influence of CTS on TTA measurements and developed a formula to calculate the necessary adjustment in measurement of TTA in stifles with CTS. We found a correlation between the tibial subluxation and the measurements for TTA, with the latter decreasing with increasing subluxation. This has to be taken into account when measuring the advancement in stifles with complete rupture of the cranial cruciate ligament. We provided a formula to calculate the necessary addition to the measured advancement.

Radiographic changes of the patellar ligament in dogs after tibial tuberosity advancement

Patellar desmopathy in dogs after tibial plateau levelling osteotomy has been described in many studies. Tibial tuberosity advancement is a biomechanically different technique. It is assumed that the patellar ligament is loaded with little force similarly as after tibial plateau levelling osteotomy. Various aspects related to secondary patellar desmopathy are not completely understood. This study deals with computed radiography measurement of patellar ligament thickness after tibial tuberosity advancement in dogs with cranial cruciate ligament rupture. The thickness of the patellar ligament in exactly predetermined locations was measured from mediolateral radiographs of stifle joints. A total of 18 dogs (20 knee joints) with cranial cruciate ligament (ligamentum cruciatum craniale) rupture underwent three radiographic examinations of the knee (preoperative examination and control examination 7 and 15 weeks after the surgery). Significant difference was found between the thickness of the patellar ligament in the first and second examinations. Some of the demographic factors possibly related to patellar ligament thickness (age, sex, body weight, type of cranial cruciate ligament rupture, arthrotomy, cage size, meniscal injury, time between surgery and radiographic examination) were analyzed. However, statistical analyses did not show any effect of these factors on the thickness of the patellar ligament, except for the time between surgery and radiographic examination. These findings can extend the surgeons’ knowledge of biomechanical aspects of tibial tuberosity advancement.

Surgical and postoperative complications associated with tibial tuberosity advancement for cranial cruciate ligament rupture in dogs: 458 cases (2007–2009)

To describe the surgical and postoperative complications encountered with tibial tuberosity advancement (TTA) performed in dogs with cranial cruciate ligament-deficient stifle joints. Retrospective case series. 458 dogs (TTA performed on 501 stifle joints). During the 2-year period, 624 TTA procedures had been performed in dogs for correction of cranial cruciate ligament deficiency. Five hundred one stifle joints in 458 dogs fit the criteria for inclusion; 43 dogs had had TTAs performed on both stifle joints. Historical data and complications reported were analyzed. Following 501 TTA surgeries, there were 95 instances of complications reported. In 7 stifle joints, 2 complications occurred. The most common complication was incisional infection and inflammation. Stifle joints with medial menisci that did not undergo medial meniscal release had a high incidence of subsequent injury, and meniscal tear was the most common complication treated by a second surgery. A partially torn cranial cruciate ligament left in situ at the time of TTA did not protect against subsequent injury of an intact, unreleased medial meniscus. Most fractures were identified on routine follow-up radiography and were rarely treated. In terms of preoperative factors, high body weight (> 40 kg [88 lb]) and a high preoperative patellar tendon angle were significantly associated with complications. High body weight and preoperative patellar tendon angle were significantly associated with complications following TTA in dogs. Subsequent meniscal tear was the most common reason for second surgery, suggesting that medial meniscal release of intact menisci should be considered when performing TTA in dogs.

Theoretical discrepancy between cage size and efficient tibial tuberosity advancement in dogs treated for cranial cruciate ligament rupture

To calculate the difference between the desired tibial tuberosity advancement (TTA) along the tibial plateau axis and the advancement truly achieved in that direction when cage size has been determined using the method of Montavon and colleagues. To measure the effect of this difference on the final patellar tendon-tibial plateau angle (PTA) in relation to the ideal 90°. Trigonometry was used to calculate the theoretical actual advancement of the tibial tuberosity in a direction parallel to the tibial plateau that would be achieved by the placement of a cage at the level of the tibial tuberosity in the osteotomy plane of the tibial crest. The same principle was used to calculate the size of the cage that would have been required to achieve the desired advancement. The effect of the difference between the desired advancement and the actual advancement achieved on the final PTA was calculated. For a given desired advancement, the greater the tibial plateau angle (TPA), the greater the difference between the desired advancement and the actual advancement achieved. The maximum discrepancy calculated was 5.8 mm for a 12 mm advancement in a case of extreme TPA (59°). When the TPA was less than 31°, the PTA was in the range of 90° to 95°. A discrepancy does exist between the desired tibial tuberosity advancement and the actual advancement in a direction parallel to the TPA, when the tibial tuberosity is not translated proximally. Although this has an influence on the final PTA, further studies are warranted to evaluate whether this is clinically significant.

Effect of Tibial Plateau Leveling Osteotomy on Patellar Tendon Angle: A Radiographic Cadaveric Study

To determine the effect of tibial plateau leveling osteotomy (TPLO) on patellar tendon angle (PTA) in dogs. Cadaveric radiographic study. Pelvic limb pairs (n=5) obtained from skeletally mature dogs, weighing 22-36 kg. TPLO was performed using a radiolucent jig that allowed for plateau segment rotation to a tibial plateau angle (TPA) of 15 degrees, 6 degrees, and 0 degrees. Before, and at each of the prescribed rotations, PTA was measured by the tibial plateau (PTA(TP)) and common tangent (PTA(CT)) methods with the stifle positioned at 135 degrees of flexion. Linear regression analysis was performed to evaluate the correlation between TPA and PTA. At a mean (+/-SD) TPA of 5.9+/-0.7 degrees, mean+/-SD PTA(TP) and PTA(CT) were 94.1+/-1.6 degrees and 86.8+/-2.5 degrees, respectively. A linear correlation was observed between TPA and PTA(TP) (r=0.85) and between TPA and PTA(CT) (r=0.61). Based on the regression equation of TPA and PTA(CT), a TPA of 12 degrees corresponded to a PTA(CT) of approximately 90 degrees. TPLO to a TPA of 6 degrees reduces PTA to values similar to those recommended when performing tibial tuberosity advancement in dogs with cranial cruciate ligament insufficiency. TPLO may neutralize tibial thrust by modifying PTA as well as decreasing TPA. TPLO to a TPA of 6 degrees may not be necessary to neutralize the cranial tibial thrust according to the plateau rotation based on PTA(CT) measurement.

Correlation of Radiographic Changes after Tibial Tuberosity Advancement in Dogs with Cranial Cruciate‐Deficient Stifles with Functional Outcome

To (1) evaluate radiographic changes associated with osteoarthrosis (OA) before and after tibial tuberosity advancement (TTA) and (2) determine if these changes are indicative of limb function as determined by kinetic gait analysis. Prospective clinical study. Dogs (n=35) with cranial cruciate ligament (CCL) deficient stifles (38). Variables recorded were: complete or partial CCL rupture, meniscal lesions, arthroscopically graded cartilage lesions, complications, and revision surgeries. Radiographic evaluation and kinetic gait analysis (vertical ground reaction forces [GRFs]) were conducted pre- and 4-16 months postoperatively (mean, 5.9 months). Radiographs were evaluated without knowledge of operative findings and functional outcome. A score (0-3) based on new bone production at 11 specific sites was used to grade OA. Soft tissue changes were classified separately as normal or excessive. Preoperative scores were correlated with clinical variables. Postoperative scores and progression of OA scores were correlated with clinical variables and GRFs. OA remained unchanged in 17 joints and progressed in 21 (55%). Dogs with meniscal lesions had higher OA scores preoperatively, but not at follow-up. Dogs with severe cartilage lesions at surgery had more progression of OA. GRFs improved after surgery and were not correlated with any of the radiographic OA scores. Progression of OA was greater in the presence of severe cartilage lesions at surgery. OA scores were not correlated with GRFs. Progression of OA is generally expected to occur after TTA despite improvement of limb function.

Force plate gait analysis to assess limb function after tibial tuberosity advancement in dogs with cranial cruciate ligament disease

To assess functional outcome in dogs with cranial cruciate ligament (CrCL) disease after tibial tuberosity advancement (TTA) using force plate gait analysis, and to evaluate parameters potentially influencing outcome. Prospective clinical study. Consecutive clinical patients (n = 37) with CrCL-deficient stifles (n = 40). The stifle joints were examined arthroscopically prior to TTA. Meniscal release was not performed if the medial meniscus was intact. Open medial arthrotomy and partial meniscectomy were performed in the presence of meniscal tears. Vertical ground reaction forces were measured preoperatively and at follow-up examinations four to 16 months postoperatively (mean: 5.9 months). The ground reaction forces of a group of 65 healthy dogs were used for the comparison. The potential effects of clinical parameters on functional outcome were evaluated statistically. Complete CrCL rupture was identified in 28 joints, and partial CrCL rupture in 12 joints. The medial meniscus was damaged in 21 stifles. Vertical ground reaction forces were significantly higher at follow-up (P < 0.01), but remained significantly lower than those of control dogs (P < 0.01). Complications were identified in 25% of joints, and the dogs with complications had significantly lower peak vertical forces at follow-up than the dogs without complications (P = 0.04). Other clinical parameters did not influence outcome. Tibial tuberosity advancement significantly improved limb function in dogs with CrCL disease, but did not result in complete return to function. Complications adversely affected functional outcome. A return to a function of approximately 90% of normal can be expected in dogs with CrCL disease undergoing TTA.