Modified tibial tuberosity advancement procedure with tuberosity advancement in excess of 12 mm in four large breed dogs with cranial cruciate ligament-deficient joints

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.

Cranial cruciate ligament rupture in small dogs (<15 kg): a narrative literature review

Small breed dogs (<15 kg) affected by cranial cruciate ligament rupture secondary to cranial cruciate ligament disease are usually middle-aged (mean age at presentation: 5.4 to 9.8 years); terrier breeds, miniature and toy poodles are over-represented. Small breed dogs have a different morphology of the proximal tibia compared to medium and large breed dogs with a steep tibial plateau angle (mean tibial plateau angle 28.8° to 36.3°), absent base of the flare of the tibial tuberosity and a caudally bowed fibula. There is a lack of evidence regarding the optimal management of cranial cruciate ligament rupture in small dogs. The treatment options consist of conservative management, extracapsular stabilisation, cranial closing wedge ostectomy, tibial plateau levelling osteotomy and tibial tuberosity advancement. The limited evidence available shows that conservative management is likely to result in prolonged recovery time (average time to recovery approximately 4 months). There is paucity of reports focussing on extracapsular stabilisation in small breed dogs, and questions have been raised regarding the early failure of the extracapsular suture subject to higher loads due to the steep tibial plateau angle of small breed dogs. Cranial closing wedge ostectomy and tibial plateau levelling osteotomy have been reported to have low major complication rates and good subjective outcomes. It is controversial whether tibial tuberosity advancement is a suitable technique in dogs with steep tibial plateau angle, which includes most small breed dogs.

A retrospective evaluation of complications associated with forkless tibial tuberosity advancement performed in primary care practice

OBJECTIVE

To report postoperative complications associated with forkless tibial tuberosity advancement (TTA) performed in primary care veterinary practice and to compare results with previous publications.

STUDY DESIGN

Retrospective study.

SAMPLE POPULATION

Three hundred seventy-four forkless TTAs in 329 dogs performed by six nonspecialist veterinarians.

METHODS

Medical records of dogs treated with a standard forkless TTA (2013-2016) and with at least 12 months of postoperative follow-up were reviewed. Complications recorded by the referring practice or the operating veterinarian were classified as minor (medically treated) or major (surgically treated).

RESULTS

Complications occurred in 57 of 374 (15.2%) TTAs; 28 (7.5%) complications were major, and 29 (7.7%) complications were minor. Postliminary meniscal injuries were documented in 12 of 374 (3.2%) TTAs (12/57 major complications) and were more common when the ratio of cage size to bodyweight was ≤0.25 (P = .019). Mean TTA (cage size) was greater in this population than what has been previously reported for a lower median bodyweight.

CONCLUSION

The incidence of major complications was low and within the range previously reported for TTA in referral practice after adjusting for study design. The magnitude of advancement was greater, and the incidence of postliminary meniscal injury was lower than what has been previously reported, after accounting for dogs that had a preliminary meniscal injury or medial meniscal release.

CLINICAL SIGNIFICANCE

Forkless TTA may be successfully performed by experienced veterinarians in primary care practice with a low rate of complications. The incidence of postliminary meniscal injury may be reduced by a greater degree of advancement of the tibial tuberosity.

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.

Comparison of three imaging modalities used to evaluate bone healing after tibial tuberosity advancement in cranial cruciate ligament-deficient dogs and comparison of the effect of a gelatinous matrix and a demineralized bone matrix mix on bone healing - a pilot study

Background

Bone healing and assessment of the state of bone bridging is an important part of clinical orthopedics, whether for fracture healing or for follow up of osteotomy procedures. Tibial tuberosity advancement (TTA) is designed to restore stability in cruciate deficient stifle joints by advancing the tuberosity while creating an osteotomy gap. The current study aims to: 1) compare three different imaging modalities to assess bone healing: ultrasound, radiographs and computed tomography (CT) and, to 2) compare the effect of a gelatinous matrix (GM) versus a demineralized bone matrix mix (DBM mix) on bone healing and bridging of this osteotomy gap in 10 otherwise healthy client-owned dogs with cranial cruciate ligament insufficiency. Osseous union of the osteotomy gap was evaluated with ultrasound, radiographs and CT at one, two, and 3 months postoperatively. Dogs were randomly selected to receive GM or DBM mix to fill the osteotomy gap created during the TTA procedure. Bone healing was assessed subjectively on all modalities as well as scored on radiographs and measured using Hounsfield units (HUs) on CT. Time to heal based on ultrasound, radiographs and CT were statistically compared between groups with significance set at p < 0.05.

Results

All osteotomy gaps were bridged with bone within 3 months for all modalities. Bridging bone was diagnosed in 5.6 weeks, 10.4 weeks and 9.6 weeks based on ultrasound, radiographs, and CT, respectively, in dogs treated with DBM mix. In dogs treated with GM osseous union was diagnosed in a mean of 4.0 weeks, 9.6 weeks and 7.2 weeks based on ultrasound, radiographs and CT. Ultrasound diagnosed osseous union significantly faster than both CT and radiographs (p < 0.001). The dimensions of the newly formed bone differed between treatment groups with the central portion of the bone only providing a small bridge in GM cases. Although bridging of the osteotomy gap occurred earlier in the group that received GM, no significant statistical difference was found between the two groups.

Conclusions

Radiographs overestimate the time needed for osseous union of the osteotomy gap. All osteotomy sites healed radiographically within 3 months.

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.

Measurement of the patellar tendon-tibial plateau angle and tuberosity advancement in dogs with cranial cruciate ligament rupture

Objectives: To (i) compare agreement of the common tangent (CT) and tibial plateau angle (TP) methods in terms of measuring the patellar tendon angle (PTA) and required advancement and (ii) determine the intraand inter-observer reliability of observers who measured PTA and the advancement.

Methods: Six observers were divided into three groups based on their level of experience. They measured the PTA and the required advancement on 43 radiographic images of the tibiae of dogs affected by cranial cruciate ligament rupture. Each observer repeated the measurements three times with each method. The inter-technique (interT), intra-observer (intraO), and interobserver (interO) reliabilities were evaluated, assessed by calculating the intraclass correlation coefficient (ICC), and represented by Jones plots.

Results: The agreement between PTA-CT and PTA-TP was low (the ICC interT values ranged from 0.11 to 0.4). The PTA-CT was associated with moderate intra-observer reliability (ICC intraO, CT = 0.61) and poor interobserver reliability (ICC interO, CT = 0.33). The PTA-TP was associated with good intra-observer reliability (ICC intraO, TP = 0.75) and moderate interobserver reliability (ICC interO, TP = 0.59). Interobserver reliability did not depend on the level of experience. The advancement measurements were associated with reliability results similar to those obtained for PTA. Jones’ plots showed that the CT method consistently yielded lower PTA and advancement values than the TP method.

Conclusion: Given its poor reliability, the CT method is not recommended.

Effect of tibial subluxation on the measurements for tibial tuberosity advancement in dogs with cranial cruciate ligament deficiency

Objectives: 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.

Methods: 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 interand intra-observer differences.

Results: Measurements of CTS and preoperative TTA showed a good to excellent interand 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.

Conclusion: 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.

Comparison of radiographic measurements of the patellar tendon-tibial plateau angle with anatomical measurements in dogs

Objective: To evaluate the validity of the common tangent and conventional tibial plateau angle methods for measuring the patellar tendon angle (PTA) in dogs.

Methods: Radiographs of cadaveric stifles (n = 20) placed at 135° in true lateral position were obtained to measure the PTA with both methods. A Kirschner wire was inserted perpendicularly to the patellar tendon at its insertion on the tibia and the stifle was dissected. Two Kirschner wires were then used to identify the anatomical landmarks of the tibial plateau. A digital image was obtained of the proximal tibia in true lateral position. Six blinded observers measured each PTA digitally while the anatomical PTA was determined by an independent blinded observer from the angle between the line representing the tibial plateau and the Kirschner wire representing the perpendicular to the patellar tendon. The agreement between the methods was determined statistically from an intraclass correlation coefficient (ICC).

Results: The global ICC for the common tangent method (0.44) and for the conventional method (0.4) indicated that their overall validity is poor. The measurements obtained by common tangent method and conventional method were respectively below and above the anatomical measurements. The reproducibility of the PTA measurements based on images of the dissected stifles was very good.

Clinical significance: Both the common tangent and conventional methods show poor concordance with the anatomical measurement of PTA. Further studies are needed to determine if errors in measurements affect the clinical outcome.

Variation of tibial plateau geometry and cruciate ligament coordinates in six breeds of dogs

Objectives: The first aim of this study was to examine whether or not variations concerning the conformational characteristics of the proximal surface of the tibial plateau exist among six different dog breeds as well as within the same breed. The second aim of this study was to determine the coordinates of the cruciate ligaments.

Methods: One hundred and four tibias of 52 mature dogs from six different breeds were used. Photographs of the proximal surface of tibial plateau were taken, and measurements for the length, width and area of the tibial plateau, and the lateral and medial condyles were taken. In addition, the intercondylar width, height of Gerdy's tubercle, popliteal notch depth, and extensor groove depth were measured and recorded. The quotients from these measurements were calculated and compared amongst the dog breeds. The coordinates of the cruciate ligaments, according to the centre of tibial plateau, were also determined.

Results: Based on the calculated quotients, variations in the geometry of the tibial plateau geometry were common among the breeds. Within the same breed, on the other hand, length and width measurements of the tibial plateau were the least variable parameters among the other parameters examined. The cranial cruciate ligament was located in front of the surface centre of tibial plateau in all breeds. The position of cranial cruciate ligament was more variable in the craniocaudal direction than that observed in the mediolateral direction; this was the exact opposite of caudal cruciate ligament.

Clinical significance: The inter-breed variations of the quotients determined in the present study may facilitate attempts aimed to assess the risk factors of stifle joint injury and to design total knee prostheses.

Comparison of complications following tibial tuberosity advancement and tibial plateau levelling osteotomy in very large and giant dogs 50 kg or more in body weight

OBJECTIVES

To analyse and compare major complications in dogs ≥50 kg undergoing tibial tuberosity advancement (TTA) or tibial plateau levelling osteotomy (TPLO) for treatment of cranial cruciate ligament disease.

METHODS

Medical records and radiographs of client-owned dogs (≥50 kg) treated for cranial cruciate ligament disease with either TTA or TPLO between January 2011 and November 2015 were reviewed. Ninety-one TTA cases and 54 TPLO cases met the study inclusion criteria. All complications within one year of surgery were recorded. Major complications were those requiring surgical revision or intervening medical therapy to resolve. Logistic regression analysis evaluated for associations with major complication occurrence. Major complications were statistically compared between TTA and TPLO treatment groups.

RESULTS

Incidence of major complications following TTA and TPLO surgery were 19.8% and 27.8%, respectively. Surgical site infection (SSI) was the single most common major complication following both TTA (15.4%) and TPLO (25.9%) surgery. There were no significant differences between TTA and TPLO treatment regarding the rate of SSI, surgical revision, or overall occurrence of major complications. Postoperative antibiotic therapy significantly reduced the risk of a major complication in all dogs ≥50 kg (p = 0.015; OR: 0.201: 95%CI: 0.055-0.737).

CLINICAL SIGNIFICANCE

Major complications occurred frequently following TTA and TPLO treatment of cranial cruciate ligament disease in dogs ≥50 kg. The increased chance for SSI should be considered and postoperative antibiotic therapy is recommended.

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.

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.

Clinical audit for the tibial tuberosity advancement procedure: establishing the learning curve and monitoring ongoing performance for the tibial tuberosity advancement procedure using the cumulative summation technique

OBJECTIVES

To quantitatively assess the learning curve for the tibial tuberosity advancement (TTA) procedure performed by a single surgeon using the cumulative summation (CUSUM) technique and to determine if surgeon performance remained under control (i.e. within specified quality boundaries) after the learning curve had been climbed.

STUDY DESIGN

Retrospective study.

ANIMALS

Dogs (n = 122) with cranial cruciate ligament deficient stifles (n = 167).

METHODS

Records of all dogs that had a TTA procedure performed by the same surgeon were reviewed. Cases were included if the following information was available: weight, breed, date of surgery, presence of partial or full cruciate rupture, meniscal pathology, occurrence and description of postoperative complications and treatment with a minimum of 12 months follow-up. Patients were excluded if they had a concurrent illness. Major complications were defined as those requiring revision surgery. The CUSUM technique was used to determine the time taken for the surgeon to reach a pre-defined level of competency and to monitor ongoing performance.

RESULTS

Major complications occurred in 15 out of 167 procedures (9%) within 12 months of TTA surgery. The complication rate decreased as surgical experience was gained with the technique, however the learning curve continued until the 22nd procedure. Thereafter, despite the target complication rate being re-set at a lower level, the surgeon's performance remained acceptable, i.e. within the revised quality boundary.

CLINICAL SIGNIFICANCE

The CUSUM technique was used for clinical audit, to determine the learning curve for the TTA procedure for a single surgeon, and to monitor ongoing performance. An experienced general practitioner had a learning curve of 22 procedures and complication rates were within the published ranges.

Mechanical testing of a new osteotomy design for tibial tuberosity advancement using the Modified Maquet Technique

OBJECTIVES

To evaluate the mechanical properties of the distal cortical hinge associated with a new osteotomy design for the Modified Maquet Technique (MMT).

STUDY DESIGN

Ex vivo mechanical study.

METHODS

The osteotomy was started 10 mm caudal to the tibial tuberosity and extended over 150% of the length of the tibial crest; it was slightly curved distally to stay at a distance of 2 to 4 mm from the cranial cortex, according to the body weight. Ninety-six tibiae were tested in advancement, and 60 tibiae were axially loaded perpendicular to the tibial plateau, until failure of the crest. Desired advancement was measured using the common tangent method in 60 tibiae. Angle of opening, thickness, and area of the cortical hinge were recorded.

RESULTS

Desired advancement of 6 mm, 9 mm, 12 mm and 15 mm was recorded in 16, 12, 18 and 14 tibiae respectively. Mean maximal advancement in these bones was 15.6 ± 6.4 mm, 20.8 ± 5.2 mm, 21.3 ± 5.2 mm and 22.7 ± 5.2 mm respectively. The desired advancement was reached in all but one tibia. Advancement was mainly influenced by the angle of opening and the stiffness of the cortical hinge. Mean ultimate load to failure was 6.12 ± 2.4 times the body weight. It was significantly associated with the body weight, thickness, and area of the cortical hinge.

CLINICAL RELEVANCE

Mean maximal advancement was higher than clinically required without occurrence of fissure or fracture. Ultimate load to failure and maximal advancement could be predicted using calculated formulae.

Preliminary experience of a modified Maquet technique for repair of cranial cruciate ligament rupture in dogs

The modified Maquet technique (MMT) uses the same principle as the tibial tuberosity advancement (TTA) for stabilization of the cranial cruciate ligament-deficient stifle in the dog. In the MMT, the tibial tuberosity is advanced in a similar manner to that used in the TTA, however the means by which the tibial crest is stabilized differs. The plate and fork originally described by Montavon et al. are not used (7). The MMT was first described by Maquet for use on humans; it leaves intact a distal bony attachment to the tibial shaft, and the tuberosity is either reinforced or not by a figure-of-eight wire. In this paper, we describe the MMT, and we report the results of our first 20 canine patients with cranial cruciate ligament rupture that were treated by the MMT. Mean clinical bone healing time was 6.8 weeks (range 4 to 12 weeks). The evidence provided by this clinical communication suggests that it is technically possible to achieve an advancement of the tibial tuberosity without the need for a plate. The MMT deserves consideration as a primary treatment option for cranial cruciate ligament rupture in dogs, and further evaluation in large clinical studies. Long-term follow-up and force plate analysis would be necessary to compare the MMT to both the TTA and the tibial plateau levelling osteotomy.