The Effect of Preoperative Planning Method on Recommended Tibial Tuberosity Advancement Cage Size

Comparison and interobserver reliability of three different methods for measuring the amount of the tibial tuberosity advancement in the preoperative planning of TTAT

INTRODUCTION

The goal of preoperative planning techniques for advancement of the tibial tuberosity is to determine the amount of advancement required to achieve a postoperative patellar tendon angle of 90° and to select the optimal wedge size to achieve this target.

MATERIAL AND METHODS

Three radiographic methods for determining the advancement distance for the tibial tuberosity were evaluated for comparability and interobserver reliability. Among the methods developed, we decided to include the common tangent method, the tibial anatomy-based method, and the Bielecki method. For all techniques, radiographs were taken in mediolateral projection with the knee joint flexed at 135°. Three observers with different levels of experience independently evaluated and scored the degree of osteoarthritis for each stifle, as previously described, and performed measurements of the amount of advancement of the tibial tuberosity on 33 stifles using common tangent method, tibial anatomy-based method, and Bielecki method.

RESULTS

According to the results, the overall score for osteoarthritis in the mediolateral view was influenced by the experience of the observers, which contradicts the results from a previous study. Regarding the measurement methods used to assess advancement, poor interobserver reliability was found for common tangent method and Bielecki method, while only a slightly moderate interobserver agreement was found for tibial anatomy-based method.

DISCUSSION

These results are inconsistent with data collected by Bielecki and colleagues. Moreover, measurements from common tangent method and tibial anatomy-based method were overlapping, as confirmed previously. Conversely, Bielecki method showed no agreement with the other methods included in the present study, with a significantly higher mean rank, probably due to its correction formula. Based on the results of the present study, tibial anatomy-based method has better interobserver reliability and is easier to perform according to the observers.

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°.

Comparison of the short-term complications of TTA-rapid and modified cTTA procedures

The objective of this retrospective study was to determine the complications of the first 30 tibial tuberosity advancement rapid (TTA-rapid) and 30 modified circular tibial tuberosity advancement (mcTTA) procedures performed by our team, and to compare the results with the findings reported in the literature. Our research was based on 30 procedures in each group. All dogs were client-owned. Data were collected only for the study of cases that had a minimum follow-up period of 3 months. Intraoperative (IO) and postoperative (PO) complications were assessed, with the latter divided into two subgroups: major and minor. Results obtained for the TTA-rapid group: IO complications 23.3% (7/30), major PO complications 13.3% (4/30), minor PO complications 16.7% (5/30). Results of the mcTTA group: IO complications 0% (0/30), major PO complications 3.3% (1/30), minor PO complications 20% (6/30). Comparing the complication rates, we found that there was a significant difference between the two groups in the occurrence of IO complications (P = 0.01054); however, there was no significant difference in the incidence of major (P = 0.3533) and minor (P > 0.9999) PO complications between groups. Our results are consistent with the findings reported in the literature and suggest that both techniques are efficient and carry a relatively low complication rate.

Determination of the Stifle Angle at Standing Position in Dogs

Simple Summary

The cranial cruciate ligament rupture is one of the most common orthopaedic diseases encountered in dogs. Surgical techniques have been developed to stabilize the stifle, with an overall accepted benefit of tibial osteotomies, among which is the tibial tuberosity advancement. Prior to surgery, the required tibial tuberosity advancement must be determined on a strict lateral radiographical view of the affected stifle with femur and tibia at an angle of 135° as initially recommended. We sought to determine if this particular stifle angle around mid-stance phase was similar among multiple dog breeds. A mean value of stifle angle of 145° was obtained. Mean stifle angle at mid-stance phase in a healthy dog is regularly higher than 135° and is likely breed and individual dependent. The pre-operative measurement of the required advancement made on stifles in 145° extension, a value close to full physiological extension, could contribute to decreasing the incidence of late post-operative meniscal lesion, consecutive to the underestimation of the tibial tuberosity advancement.

Abstract

Background: The cranial cruciate ligament rupture is one of the most common orthopaedic diseases encountered in dogs. Surgical techniques have been developed to stabilize the stifle, with an overall accepted benefit of tibial osteotomies among which is the tibial tuberosity advancement (TTA). Prior to surgery, the required TTA must be determined on a strict lateral radiographical view of the affected stifle with femur and tibia at an angle of 135° as initially recommended. This value, initially determined in only two dog breeds, has been considered the mean standard value of the canine stifle angle during the mid-stance phase. Methods: We sought to determine if this particular stifle angle around mid-stance phase was similar among multiple dog breeds. We built up a custom-made radiographic system for stifle angle measurement in standing dogs. Results: A mean value of stifle angle of 145° was obtained. Mean stifle angle at mid-stance phase in a healthy dog is regularly higher than 135° and is likely breed and individual dependent. Conclusions: The pre-operative measurement of the required TTA made on stifles in 145° extension, a value close to full physiological extension could contribute to decreasing the incidence of late post-operative meniscal lesion, consecutive to underestimation of TTA.

Tibial Tuberosity Advancement Techniques (TTAT): A Systematic Review

(1) Background: Several surgical techniques were described for the treatment of cranial cruciate ligament rupture in dogs. This report aims to critically review the available literature focused on preoperative planning, surgical procedure, follow-up, and complications of cranial cruciate ligament rupture treated by tibial tuberosity advancement techniques; (2) Methods: three bibliographic databases: PubMed, Google Scholar, and Scopus were used for a board search of TTAT (canine OR dog). Five GRADE recommendations according to Grading of Recommendations Assessment, Development and Evaluation and Joanna Briggs Institute Critical Appraisal Checklists were applied to the studies included. Data regarding preoperative planning (a measure of advancement), meniscal disease (meniscectomy, meniscal release, and late meniscal tears), and postoperative patellar tendon angle were recorded. Time frame, outcome, and complications were classified according to Cook’s guidelines; (3) Results: from 471 reports yielded, only 30 met the inclusion criteria. The common tangent method was the most commonly reported measurement technique for preoperative planning. The 40.21% of stifles presented meniscal tears at surgery, while 4.28% suffered late meniscal tears. In short-, mid-and long-term follow-ups examined showed a full/acceptable function was shown in >90% of cases. Among all new generation techniques, minor complications were reported in 33.5% of cases and major complications in 10.67%; (4) Conclusions: Compared to traditional TTA, new generation TTAT resulted effective in the treatment of cranial cruciate ligament failure, showing a lower rate of late meniscal injury but a higher rate of minor complications.

Mechanical Testing of the New Cage for Tibial Tuberosity Advancement with the Cranial Implant Fixation (TTA CF) Technique—Ex Vivo Study on Sheep Model

Simple Summary

Tibial tuberosity advancement is a method of surgical treatment of cranial cruciate ligament rupture in animals.. In previous reports, the biomechanical effectiveness of tibial tuberosity advancement surgeries was evaluated by axial pressure on the tibial tuberosity to test the strength and resistance of the fixation or by pulling on the tuberosity. To our knowledge, there are no reports that examined the strength that is needed to pull out an implant from the tibia after tibial advancement. This study is the first report that focuses on pulling out the TTA implant, which corresponds to the biointegrity and ingrowth of the TTA cage with the tibia.

Abstract

Background: Modifications of tibial tuberosity advancement are well accepted for cranial cruciate rupture repair. We compared the loads that were needed to pull the TTA CF cage out in the two groups. The first group consisted of five sheep in which osteotomy and TTA CF cage fixation were performed as assumed preoperatively. The second group consisted of five sheep in which intraoperative or postoperative discrepancies from preoperative planning were found. This is also the first report describing biomechanical testing after tibial tuberosity advancement with cranial implant fixation (TTA CF) surgical procedures. Results: A total of 10 ovine proximal tibiae were tested biomechanically by tearing out TTA CF implants from the bone. The mean maximal loaded forces to pull out the cage in Group 1, in which fixation of the implant was performed as assumed preoperatively, was 878 ± 61 N, and in Group 2, in which discrepancies from preoperative planning were found, was 330 ± 55 N. The mean implant displacement under maximal load to failure was 2.6 mm and 2.2 mm in Groups 1 and 2, respectively. There was a significant difference between Group 1 and Group 2 in the maximal loads-to-failure; however, the difference in the displacement at maximal loaded forces to pull out the cage was not significant between the groups. Conclusions: The mean maximal loaded forces to pull out the cage was significantly lower in Group 2, where discrepancies from preoperative planning were found (878 ± 61 N vs. 330 ± 55 N). The lower forces that were needed to extract the TTA CF implant from the tibia can lead to the conclusion that biointegration of the implant is also weaker. Correct positioning of the osteotomy line and TTA CF implant is essential for good biointegrity and thus for limiting complications in the form of tibial tuberosity avulsion fracture or tibial shaft fracture.

Radiographic measurement of canine stifle joint angles using four different landmark methods

This study was conducted to compare angles physically set on the stifle joints of cadaveric limbs of dogs with the results by four different radiographic methods for stifle angle measurement. Thirteen pelvic limbs from various large breeds and skeletally-mature dogs were used. The stifles were fixed at four angles: 125°, 130°, 135° and 140°. Altogether 52 radiographs were done. Each stifle angle set on the cadaver limbs was radiographically measured using four sets of landmarks (the goniometric, long axis, eminence and kinematic methods). We found similarity between angles physically set on cadaver limbs and radiographically measured using the long axis method (P > 0.05). The goniometric method showed similarity in group of limbs with the stifle fixed at 140° (P > 0.05), and other measurements differed significantly (P < 0.05). Eminence and kinematic method measurements were different compared to the angle of fixation of the stifle on the cadaver (P < 0.05) but similar compared to each other (P > 0.05). The method of stifle joint angle measurement should be considered when comparing similar studies, and also in pre-operative measurements for some tibial osteotomies aimed at stabilizing the joint after cranial cruciate ligament rupture.

Subsequent meniscal tears following tibial tuberosity advancement and tibial plateau leveling osteotomy in dogs with cranial cruciate ligament deficiency: An in vivo experimental study

OBJECTIVE

To evaluate the short- and mid-term effects of tibial tuberosity advancement (TTA) and tibial plateau leveling osteotomy (TPLO) on subsequent meniscal tears.

STUDY DESIGN

Experimental in vivo study.

ANIMALS

Purpose-bred beagle dogs (n = 15).

METHODS

For each dog, the cranial cruciate ligaments were transected; one limb underwent TTA and the other limb underwent TPLO. Orthopedic and radiographic examinations were performed preoperatively and at 12 and 32 weeks postoperatively. Gross evaluation of the stifle joint was performed after euthanasia at 12 (n = 10) and 32 (n = 5) weeks.

RESULTS

Lameness scores were not different between TTA and TPLO limbs at any time point. Radiographic osteoarthritis scores of TTA stifles (1.33 ± 0.49) were higher than TPLO stifles (0.67 ± 0.49) (p = .002) at 12 weeks postoperatively, but there was no difference between groups at 32 weeks postoperatively. Subsequent medial meniscal tears occurred in 6/10 TTA stifles, and 0/10 TPLO stifles at 12 weeks postoperatively and in 5/5 TTA stifles, and 1/5 TPLO stifles at 32 weeks postoperatively. Subsequent lateral meniscal tears occurred in 4/5 TTA stifles at 32 weeks postoperatively. Medial meniscal total gross pathology score was higher in TTA than TPLO stifles. TTA stifles had more articular cartilage damage when compared with TPLO stifles at 32 weeks postoperatively.

CONCLUSION

In this within-dog experimental comparison, subsequent medial meniscal tears and cartilage injury was more prevalent following TTA when compared to TPLO.

CLINICAL SIGNIFICANCE

In an experimental model, TPLO protects the medial meniscus and articular cartilage better than TTA in stifles with complete cranial cruciate ligament deficiency.

Comparison of Outcome and Complications in Dogs Weighing Less Than 12 kg Undergoing Miniature Tibial Tuberosity Transposition and Advancement versus Extracapsular Stabilization with Tibial Tuberosity Transposition for Cranial Cruciate Ligament Disease with Concomitant Medial Patellar Luxation

OBJECTIVE

 The aim of this study was to describe a technique for performing miniature tibial tuberosity transposition and advancement (mTTTA). The secondary objective of this study was to compare the short-term outcome and complications in small breed dogs weighing less than 12 kg undergoing surgical correction of cranial cruciate ligament disease with concurrent medial patellar luxation via either extracapsular stabilization with tibial tuberosity transposition (ECS + TTT) or mTTTA.

STUDY DESIGN

 This is a retrospective case comparison study.

RESULTS

 There was no significant difference in overall outcome between the ECS + TTT group and the mTTTA group when comparing 8-week postoperative radiographic healing scores as well as 2- and 8-week postoperative lameness scores.

CONCLUSION

 This study concluded that the mTTTA procedure was feasible and the overall outcome and complications for the dogs that underwent ECS + TTT and those that underwent mTTTA were comparable.

Tibial tuberosity advancement technique in small breed dogs: study of 30 consecutive dogs (35 stifles)

OBJECTIVES

To assess the outcome and peri-operative complications of the tibial tuberosity advancement technique in small dogs with cranial cruciate ligament rupture.

MATERIALS AND METHODS

Cranial cruciate ligament rupture was diagnosed by positive drawer sign or tibial thrust test and confirmed at surgery in 30 dogs (35 stifles) weighing less than 15 kg. Clinical and radiographic follow-up was obtained at 4 and 12 weeks or later. Thigh diameter and affected and non-affected stifle joint flexion and extension angles were also measured.

RESULTS

At 4-week follow-up 26 of 35 (74%), eight of 35 (23%) and one of 35 (3%) showed no, mild and moderate lameness, respectively. Similarly, at 12 weeks or later the respective outcomes were 32 of 35 (91%), two of 35 (6%) and one of 35 (3%). The mean thigh diameter of affected limbs at 12 or more weeks was 96% of the mean of normal limbs and stifle range of motion reached 98% of normal extension and 97% of normal flexion. There were complications in two of 35 stifles: one screw partially inserted into the joint and postoperative wound dehiscence, both of which required surgical correction.

CLINICAL SIGNIFICANCE

The tibial tuberosity advancement technique leads to acceptable outcomes in small dogs with cranial cruciate ligament rupture.

In vivo fluoroscopic kinematography of cranio-caudal stifle stability after tibial tuberosity advancement (TTA): a retrospective case series of 10 stifles

It was the aim of the study to determine retrospectively cranio-caudal stifle instability following TTA (tibial tuberosity advancement) using fluoroscopic kinematography. Ten stifles (eight dogs, mean body weight 27.3 kg) with complete rupture of the cranial cruciate ligament and a mean follow-up of 12.8 weeks (5.4 - 28.4 weeks) after TTA underwent latero-lateral, uniplanar fluoroscopic kinematography while walking on a treadmill. Immediately before TTA, each stifle was explored arthroscopically and in the case of a longitudinal or bucket-handle tear of the caudal horn of the medial meniscus the unstable axial portion was resected. The high-speed fluoroscopic video sequences obtained were inspected visually for femoro-tibial translation (cranial drawer). The influence of postoperative patellar tendong angle (PTA), cage size and meniscal surgery on stifle stability was analyzed using logistic regression analysis. In three stifles, resection of unstable meniscal tissue was necessary. Fluoroscopically, nine out of ten stifles showed cranio-caudal instability. Three stifles were potentially overcorrected (post PTA < 90°), seven potentially undercorrected (post PTA > 90°). None of the three parameters analyzed had a significant influence on postoperative in vivo stability (p=0.0988). In conclusion, it appears that inadequate cranialization of the tibia tuberosity might be an expected result of the TTA procedure, as well as persistent cranio-caudal instability during walking. However, instability cannot solely be attributed to insufficient cranialization because three out of nine unstable stifles were sufficiently or even overcorrected (PTA ≤ 90°). Further in vivo studies are needed to resolve these conflicting findings.

Relationship between Tibial conformation, cage size and advancement achieved in TTA procedure

Background

Previous studies have suggested that there is a theoretical discrepancy between the cage size and the resultant tibial tuberosity advancement, with the cage size consistently providing less tibial tuberosity advancement than predicted. The purpose of this study was to test and quantify this in clinical cases. The hypothesis was that the advancement of the tibial tuberosity as measured by the widening of the proximal tibia at the tibial tuberosity level after a standard TTA, will be less than the cage sized used, with no particular cage size providing a relative smaller or higher under-advancement, and that the conformation of the proximal tibia will have an influence on the amount of advancement achieved.

Results

One hundred sixty-four dogs met the inclusion criteria. The mean percentage under-advancement was 15.5%. All dogs had an advancement less than the stated cage size inserted. An association between the proximal tibial tuberosity angle (increased in cases with low patellar tendon insertion), and percentage under-advancement was found, with an increase of 0.45% under-advancement for every 1 degree increase in angle a (p = 0.003). There was also evidence of a difference between the mean percentage under-advancement in breeds (p = 0.001) with the Labrador having the biggest under-advancement. Cage size (p = 0.83) and preoperative tibial plateau angle (p = 0.27) did not affect under-advancement.

Conclusions

The conformation of the tibial tuberosity and therefore the relative cage positioning have an impact on mean percentage under-advancement of the tibial tuberosity after standard TTA. In all evaluated cases, the advancement of the tibial tuberosity was less than intended by the cage size selected.

Planned wedge size compared to achieved advancement in dogs undergoing the modified Maquet procedure

Objectives: To evaluate the patellar ligament to tibial plateau angle (PL-TPA) and amount of achieved advancement in dogs that underwent the modified Maquet procedure; compare wedge sizes recommended using two different planning techniques (Orthomed and modified tibial tuberosity advancement); and evaluate anatomical factors that predict the wedge size required to obtain a 90° PL-TPA.

Methods: Pre- and postoperative radio-graphs of dogs that had a modified Maquet procedure performed were evaluated for the following: calculated wedge size using two different planning techniques, the actual wedge size used, the achieved tibial tuberosity advancement, and the changes in PL-TPA. Anatomical measurements of the tibia were evaluated and correlated with the actual wedge size.

Results: Of the 38 modified Maquet procedures identified, 53% (n = 20) had a PLTPA of 90° ± 5°. Actual achieved advancement of the tibial tuberosity was 30% less than the wedge size used. Changes in PL-TPA and tibial width persisted at eight weeks postoperatively without loss of advancement. The two planning techniques did not result in a significantly different selection of wedge size.

Clinical relevance: Current planning techniques for the modified Maquet procedure result in under-advancement of the tibial tuberosity. Both measurement techniques evaluated do not result in appropriate advancement.

Evaluation of a new method to determine the tibial tuberosity advancement distance required to reduce the patellar tendon-tibial plateau angle to 90° with the modified Maquet technique in dogs

OBJECTIVE To assess use of a new radiographic method to determine the distance by which the tibial tuberosity should be advanced to reduce the patellar tendon-tibial plateau angle (PTA) to 90° by means of the modified Maquet technique (MMT) in dogs. SAMPLE 24 pelvic limbs from 12 adult medium-sized to large-breed canine cadavers. PROCEDURES Radiographs of stifle joints at 135° extension in true lateral position were used to determine tibial tuberosity advancement distances for use in the MMT. A method was devised to incorporate the planned osteotomy axis; distal patellar translations of 0, 3, 5, or 10 mm; and advancement cage implant application level along the osteotomy site in advancement planning measurements. Concordance correlation coefficients (CCCs) were calculated to compare these adjusted advancement measurements with true advancement measurements obtained for the same joints in another study after treatment by MMT. Intraobserver, interobserver, and total agreement for selected measurements were determined by assessment of CCCs for results obtained by 3 blinded observers. RESULTS Agreement between true advancement measurements and measurements obtained with osteotomy axis and cage position method calculations that incorporated a 5-mm distal patellar translation distance was excellent (CCC, 0.96). Intraobserver and interobserver agreements for the planning measurements evaluated were good to excellent (CCC, 0.83 to 0.96). CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that the osteotomy axis and cage position method incorporating a 5-mm distal patellar translation distance has the potential to improve success rates for achieving a PTA of 90° in medium-sized to large-breed dogs undergoing MMT for treatment of cranial cruciate ligament rupture. Further research is warranted.

Tibial tuberosity advancement in small-breed dogs using TTA Rapid implants: complications and outcome

OBJECTIVE

To assess the perioperative complications and the outcome when treating small-breed dogs with cranial cruciate ligament insufficiency with tibial tuberosity advancement using the TTA Rapid implant.

MATERIALS AND METHODS

40 dogs (48 stifles) with cranial cruciate ligament insufficiency and body weight of 15 kg or less. Diagnosis was confirmed by arthroscopy or arthrotomy, followed by tibial tuberosity advancement surgery. Six weeks after surgery, the dogs were re-evaluated with clinical examination and radiography. Mid- to long-term outcome was assessed using client questionnaire.

RESULTS

Intraoperative complications consisted of four osteotomy-related fissures through the cranial cortex; two complete fissures were stabilised with a screw, the others healed without intervention. After surgery there were two tibial fractures and two incisional complications. Six weeks postoperatively, limb function was good to excellent in 43 dogs (94%). Two late meniscal injuries occurred. The overall major complication rate was 7/48 14·6%). Mid- to long-term follow-up information was available for 43 stifles: 34 stifles (79%) were free of lameness at a median of 72 weeks postoperatively. The outcome was rated excellent by 88% of the clients and good by 7%.

CLINICAL SIGNIFICANCE

The use of TTA Rapid implants is an alternative for treatment of cranial cruciate ligament insufficiency in small-breed dogs, with complication rates comparable to those recorded in larger breeds and to other techniques, and with a high degree of owner satisfaction.

Effect of proximal translation of the osteotomized tibial tuberosity during tibial tuberosity advancement on patellar position and patellar ligament angle

Background

Cranial cruciate ligament insufficiency is a common orthopaedic problem in canine patients. This cadaveric and radiographic study was performed with the aim of determining the effect of proximal translation of the tibial tuberosity during tibial tuberosity advancement (TTA) on patellar position (PP) and patellar ligament angle (PLA).

Results

Disarticulated left hind limb specimens harvested from medium to large breed canine cadavers (n = 6) were used for this study. Limbs were mounted to Plexiglass sheets with the stifle joint fixed in 135° of extension. The quadriceps mechanism was mimicked using an elastic band. Medio-lateral radiographs were obtained pre-osteotomy, after performing TTA without proximal translation of the tibial tuberosity, and after proximal translation of the tibial tuberosity by 3mm and 6mm. Radiographs were blinded to the observer for distance of tibial tuberosity proximalization following radiograph acquisition. Three independent observers recorded PP and PLA (tibial plateau method and common tangent method). Comparisons were made between the stages of proximalization using repeated measures ANOVA. Patellar position was found to be significantly more distal than pre-osteotomy, if the tibial tuberosity was not translated proximally (P = 0.001) and if it was translated proximally by 3mm (P = 0.005). The difference between pre-osteotomy PP and 6mm proximalization was not significant. The PLA was significantly larger if the tibial tuberosity was not translated proximally compared to tibial tuberosity proximalization of 6mm using the tibial plateau and the common tangent methods (P = 0.006 and P = 0.015 respectively).

Conclusions

Proximalizing the tibial tuberosity during TTA helps in maintaining vertical position of the patella in the patellar groove. Proximalization of the tibial tuberosity reduces PLA when compared to TTA without tibial tuberosity proximalization.

Comparison of desired radiographic advancement distance and true advancement distance required for patellar tendon-tibial plateau angle reduction to the ideal 90° in dogs by use of the modified Maquet technique

OBJECTIVE To evaluate the validity of 2 radiographic methods for measurement of the tibial tuberosity advancement distance required to achieve a reduction in patellar tendon-tibial plateau angle (PTA) to the ideal 90° in dogs by use of the modified Maquet technique (MMT). SAMPLE 24 stifle joints harvested from 12 canine cadavers. PROCEDURES Radiographs of stifle joints placed at 135° in the true lateral position were used to measure the required tibial tuberosity advancement distance with the conventional (A^M) and correction (A^E) methods. The MMT was used to successively advance the tibial crest to A^M and A^E. Postoperative PTA was measured on a mediolateral radiograph for each advancement measurement method. If none of the measurements were close to 90°, the advancement distance was modified until the PTA was equal to 90° within 0.1°, and the true advancement distance (TA) was measured. Results were used to determine the optimal commercially available size of cage implant that would be used in a clinical situation. RESULTS Median A^M and A^E were 10.6 mm and 11.5 mm, respectively. Mean PTAs for the conventional and correction methods were 93.4° and 92.3°, respectively, and differed significantly from 90°. Median TA was 13.5 mm. The A^M and A^E led to the same cage size recommendations as for TA for only 1 and 4 stifle joints, respectively. CONCLUSIONS AND CLINICAL RELEVANCE Both radiographic methods of measuring the distance required to advance the tibial tuberosity in dogs led to an under-reduction in postoperative PTA when the MMT was used. A new, more accurate radiographic method needs to be developed.

Electrocautery technique for proximal tibial epiphysiodesis in Labrador retriever puppies: experimental study

ABSTRACT There are few studies about the treatment options for cranial cruciate ligament rupture in growing dogs, especially with epiphysiodesis techniques. The aim of this study was to evaluate the electrocautery technique for proximal tibial epiphysiodesis in Labrador retriever puppies. The novel electrocautery technique was compared with the screw technique regarding the efficacy for tibial plateau leveling in growing dogs. Six healthy Labrador retriever puppies were divided into two groups. The screw technique was used in one group and the electrocautery technique was used in the other group. Both proximal tibial epiphysiodesis techniques for tibial plateau leveling were effective in achieving reduced tibial plateau angle and did not cause significant joint changes. The screw technique was more invasive and caused slightly greater morbidity than the electrocautery technique. The electrocautery technique seems to be a good alternative for proximal tibial epiphysiodesis in young dogs.

Effect of tibial tuberosity advancement on cranial tibial subluxation in the feline cranial cruciate deficient stifle joint: An ex vivo experimental study

The effects of Tibial Tuberosity Advancement (TTA) on Cranial Tibial Subluxation (CTS) and Tibial Rotation Angle (TRA) were evaluated in a model of feline Cranial Cruciate Ligament (CrCL)-deficient stifle joint. Ten hindlimbs of adult cats were used. Quadriceps and gastrocnemius muscles were simulated using cables, turnbuckles and a spring. An axial load of 30% body weight was applied. The stifle and talocrural joint angles were adjusted to 120°. Patellar tendon angle (PTA), CTS and TRA were measured radiographically before and after CrCL section, after TTA and after additional advancement by 1 and 2mm. CrCL section resulted in a CTS of 8.1±1.5mm and a TRA of 18.4±5.7 °. After TTA, PTA was significantly decreased from 99.1±1.7° to 89.1±0.7°; CTS and TRA did not change significantly (7.8±1.0mm and 15.9±5.7° respectively). Additional advancement of the tibial tuberosity by 1mm did not significantly affect CTS and TRA. Additional advancement of the tibial tuberosity by 2mm significantly reduced the PTA to 82.9±0.9°. A significant decrease of CTS (6.9±1.3mm) and TRA (14.7±3.6°) was also observed. A lack of stabilization of the CrCL deficient stifle was observed after TTA in this model of the feline stifle. Even though the validity of the model can be questioned, simple transposition of the technique of TTA from the cat to the dog appeared hazardous.

The Modified Maquet Procedure (MMP) in Dogs: Technical Development and Initial Clinical Experience

The literature about tibial tuberosity advancement surgery in dogs and humans informed the development of a version of the operation using a wedge-shaped implant of titanium foam. Computer-assisted drawing and stereolithography was used to create instruments and implants that were evaluated by cadaver surgery. A trial, involving 26 client-owned dogs with lameness due to cranial cruciate ligament failure, was started. Follow-up was done by clinical and radiographic examination after 4 wk and clinical examination again 6-11 mo after surgery. The titanium foam implant maintained tibial tuberosity advancement easily and effectively. The same major complication occurred in 2 of the first 6 cases before, a slightly modified technique was used to treat 20 dogs without complication. At mid-term follow-up (6-11 mo), 20/26 dogs (77%) had returned to full function, two dogs (7.7%) had acceptable function, two dogs (7.7%) could not be evaluated due to recent contra lateral modified Maquet procedure surgery, and two (7.7%) dogs had died for reasons unrelated to the study. This is the first clinical report of the use of titanium foam in veterinary orthopaedics. Modified Maquet procedure appears to be an effective treatment for lameness due to failure of the cranial cruciate ligament in dogs.

Comparison of the proximal tibial angles between Labrador Retrievers and other dog breeds with and without cranial cruciate ligament rupture

ABSTRACTThe influence of the proximal tibia conformation in the rupture of the cranial cruciate ligament (CCL) in dogs is still controversial, especially in Labrador Retrievers. The aim of this study was to compare the angles of the proximal tibia between Labrador Retrievers and other large breeds of dogs, both groups with and without CCL rupture. Radiographic images of 64 stifle joints were obtained and divided into four groups of 16 images. Group 1 consisted of Labrador dogs without orthopedic disorders, group 2 consisted of Labrador dogs with CCL rupture, group 3 consisted of dogs of various large breeds without orthopedic disorders, and group 4 consisted of dogs of various large breeds with CCL rupture. The radiographs were performed in mediolateral projection with the stifle joint positioned at an approximate angle of 135°. The tibial plateau angle showed an overall average of 22.17°±4.20°, and there was no statistically significant difference between the groups. The patellar ligament angle in relation to the tibial plateau had a mean of 103°±4.20°, and there was a significant difference between groups 1 and 4. The patellar ligament angle in relation to the common tangent at the tibiofemoral contact point showed an average of 99.06°±6.08°, and there was no difference between the groups. The patellar ligament insertion angle had an overall average of 51.45°±5.06°, and there was a significant difference between the two groups of normal dogs and two groups of ruptured dogs. In conclusion, the tibial plateau angle, the patellar ligament angles and the patellar ligament insertion angle do not seem to be predisposing factors for rupture of the CCL in Labrador Retriever dogs. In general, there seems to be no relationship between the angles of the proximal tibia and the CCL rupture in dogs.