Treatment Of Medial Patellar Luxation Research Articles

Combination of closing-wedge distal femoral osteotomy and modified tibial plateau levelling osteotomy for the treatment of medial patellar luxation and concomitant cranial cruciate ligament disease in dogs

Considering the prevalence of cranial cruciate ligament disease (CCLD) and concurrent medial patellar luxation (MPL) among dogs, and the concomitant bone deviations routinely identified, the aim of this study is to evaluate the efficacy of the combination between distal femoral osteotomy (DFO) and modified tibial plateau levelling osteotomy (mTPLO) for the treatment of MPL with distal femoral varus, tibial torsion, and CCLD. Dogs with concurrent MPL and CCLD that underwent DFO and mTPLO procedures were included. Subjective clinical evaluations of gait and pre-operative and immediate post-operative radiographic examinations were performed. Surgical data were documented. The anatomical lateral distal femoral angle (aLDFA), femoral varus angle, mechanical medial proximal tibial angle, and tibial plateau angle (TPA) were compared between the pre- and post-operative periods. A total of 12 dogs were included in this study. Closing-wedge DFO and mTPLO procedures were performed on 14 limbs. The mean pre-operative and post-operative aLDFA values were 104.8 ± 3.9° and 95.4 ± 2.4°, respectively. TPA values were 26.2 ± 3.7° pre-operatively and 6.3 ± 3.2° post-operatively. Bone healing was observed in 7.1 %, 71.3 %, and 85.5 % of patients at the first, second, and third follow-up, respectively. Lameness was resolved in 28.5 %, 78.5 %, and 100 % at 30, 60, and 90 days, respectively. No major peri- or post-operative complications were reported. The combination of mTPLO and DFO aligns the stifle extensor mechanism, promoting dynamic stabilization. It can be considered for the treatment of concurrent MPL and CCLD in dogs, performed as a single procedure, and is associated with favorable short-term outcomes.

Comparative analysis of post-operative rehabilitation approaches for medial patellar luxation in small-breed dogs

Background and Aim: Electrical stimulation (ES) and light amplification by stimulated emission of radiation (LASER) therapy are frequently used in post-operative rehabilitation; however, there is currently insufficient research comparing their effectiveness. This study aimed to assess the effectiveness of post-operative rehabilitation following medial patellar luxation (MPL) surgical correction by comparing ES and LASER therapy when combined with exercise. This was compared with a control group that consisted solely of post-operative home exercise implemented by the owner. Materials and Methods: We conducted a prospective clinical trial on dogs that had undergone surgical treatment for MPL. The dogs were categorized into the following three groups: The control group, which did not participate in any post-operative rehabilitation program; the ES group, which received post-operative rehabilitation involving ES therapy; and the LASER group, which underwent post-operative rehabilitation featuring LASER therapy. Results: There were no significant differences among the groups regarding the evaluation parameters, including lameness score, pain score, thigh muscle circumference, and range of motion. Although there may have been a difference in pain score in some groups, it could be attributed to the pre-operative condition of patients. These results aligned with the owner questionnaires’ canine brief pain inventory assessments, showing no significant differences between treatment groups. Conclusion: Post-operative rehabilitation for MPL correction may enhance limb usage, joint function, muscle mass, and pain relief. However, the duration and level of post-operative pain may influence the necessity for rehabilitation. In addition, ES and LASER therapy offer similar pain-relieving effects after MPL surgery; therefore, the choice between these methods depends on the availability of equipment and veterinarian preferences. Keywords: electrical stimulation, light amplification by stimulated emission of radiation therapy, medial patellar luxation, post-operative management, rehabilitation.

Comparison of the reoperation rates of three techniques for tibial tuberosity transposition in medial patellar dislocation

A common technique for the treatment of medial patellar luxation is the lateral transposition of the tibial tuberosity. Two variations of a new surgical method with a retention plate and fixation with a wire or a security plate, were tested against each other and against the existing fixation with Kirschner wires and a tension band by the number of reoperations. The new method using a retention plate and security plate showed the lowest rate of reoperations (5 %), followed by the new technique using retention plate and wire (14 %) and the existing fixation with Kirschner wires and a tension band (34 %). A possible explanation for the good result of the new method can be the fixation of the implants on the medial side of the tibia and the non-use of Kirschner wires.

Outcomes and complications of a modified tibial tuberosity transposition technique in the treatment of medial patellar luxation in dogs.

To report a modification of the tibial tuberosity transposition (m-TTT) technique used to treat medial patellar luxation (MPL) in dogs, and report its complications. Retrospective case series. Dogs (n = 235) undergoing MPL correction, using m-TTT (n = 300 stifles). Medical records and client surveys were reviewed to determine complications associated with this technique and they were compared with previously reported complications using similar techniques. Short-term minor complications included low-grade reluxation (11 stifles, 3.6%), incisional seroma (nine stifles, 3%), pin-associated swelling (seven stifles, 2.3%), patellar desmitis (six stifles, 2%), superficial incisional infection (four stifles, 1.3%), pin migration (three stifles, 1%), tibial tuberosity (TT) fracture (two stifles, 0.6%), tibial tuberosity displacement and patella alta (one stifle, 0.3%), pin-associated discomfort (one stifle, 0.3%), trochlear block fracture (one stifle, 0.3%). Short-term major complications included pin migration (three stifles, 1%), incisional infection (two stifles, 0.6%), tibial tuberosity fracture (two stifles, 0.6%), and high grade reluxation (two stifles, 0.6%). Long-term follow-up examination data were available for 109/300 (36.3%) stifles. One minor complication and four major complications were documented. All long-term complications were due to pin migration. The overall major complication rate was 4.3% (13/300 stifles), with a minor complication rate of 15% (46/300 stifles). The owner survey indicated a 100% satisfaction rate. The m-TTT technique yielded acceptable complication rates, with high owner satisfaction. The m-TTT should be considered as an alternative technique for treating dogs with MPL requiring a tibial tuberosity transposition.

Tibial Tuberosity Transposition Tool Technique in Combination with Distal Femoral Lateral Closing Wedge Osteotomy for Patellar Luxation Treatment in Five Dogs

AbstractMedial patellar luxation is a multifactorial condition resulting from a misalignment of the stifle extensor mechanism. Several techniques have been described for correcting this condition, depending on the specific morphological changes identified. This case series describes the combination of tibial tuberosity transposition tool techniques and distal lateral femoral closing wedge osteotomy in the treatment of dogs with medial patellar luxation. A combination of these two techniques was used in five dogs with varying degrees of medial luxation of the patella resulting from distal femoral varus and less than 20 degrees distal external torsion of the tibia. The combination of techniques allowed the alignment of the stifle extensor mechanism and corrected medial patellar luxation in all dogs. Radiographic bone union occurred in all dogs, with a mean time of 30 ± 2 days for tibial osteotomy and 48 ± 16 days for the femur. There was no recurrence of patellar dislocation, and no complications developed in any animal during a 1-year-long observation period. This case series demonstrates that the combination of tibial tuberosity transposition tool techniques and distal lateral femoral closing wedge osteotomy can be an effective treatment for medial patellar luxation associated with distal femoral varus with external tibial torsion less than 20 degrees.

Comparison of Semi-Cylindrical Recession Trochleoplasty and Trochlear Block Recession for the Treatment of Canine Medial Patellar Luxation: A Pilot Study.

The aim of this study was to describe an alternative method for trochleoplasty, semi-cylindrical recession trochleoplasty (SCRT), and compare it to trochlear block recession (TBR) in regard to recessed trochlear depth, patellar depth, patellar articular contact with the trochlea, recessed trochlear surface area, procedure time, complications and functional outcome. Ten dogs with bilateral grade II-III medial patellar luxations underwent bilateral simultaneous correction surgery including tibial tuberosity transposition, lateral imbrication and trochleoplasty with one stifle each undergoing TBR and SCRT. Patients received pre-and postoperative stifle computed tomography scans and pre- and 8-week postoperative pressure platform analysis and physical examinations. Recessed trochlear depth, patellar depth, trochlear surface area, patellar articular contact, procedure time, complications and functional outcomes as measured by gait analysis were compared between the two techniques. There was no significant difference in measured outcome variables between techniques at any time point. At the time of the 8-week reassessment, no patella had reluxated. Short-term follow-up shows similar functional outcomes between both techniques regarding rate of reluxation and limb function. The SCRT was subjectively easier to perform than TBR, particularly in small patients. The SCRT is an acceptable method of trochleoplasty for the treatment of medial patellar luxation in dogs and further studies evaluating long-term outcomes are justified.

Technique of Tibial Tuberosity Transposition and Advancement (TTTA) With Use of TTA-Maquet Cage-Only in Dog

Background: The most common conditions that compromise the stifle joint in dogs are medial patellar luxation (MPL) and cranial cruciate ligament (CCL) rupture. Surgical procedures are usually indicated for the treatment of these diseases. One ordinary technique for the treatment of MPL is the tibial tuberosity transposition, and one prominent technique for CCL rupture is the tibial tuberosity advancement. These techniques can be associated in one surgical procedure called tibial tuberosity transposition and advancement (TTTA) for the simultaneous treatment of both stifle diseases. The aim of this study is to report the surgical treatment of a dog with MPL and CCL rupture affecting the same joint by the TTTA technique with the use of a TTA-Maquet cage-only.Case: A 3-year-old Pitbull dog weighing 39 kg was attended at Veterinary Hospital with a history of marked lameness in the left pelvic limb. The orthopedic examination showed positive results for cranial drawer motion and tibial compression tests, and a complete CCL rupture was diagnosed. The presence of patellar luxation was evaluated by manual pressure on the patella, and grade 3 of MPL was diagnosed. Both conditions were affecting the same stifle joint. In addition, survey radiographs of the affected joint were performed. Surgical treatment was indicated by the TTTA technique. Radiographic measurements were taken to calculate the cranial tibial tuberosity advancement by the tibial plateau and the common tangent methods, and a titanium TTA-Maquet cage-only of 10.5 x 20.0 mm was selected. Linear osteotomy was performed on the tibial tuberosity with the aid of an oscillating saw, based on the Maquet hole technique. The tibial tuberosity was carefully displaced cranially and the cage was inserted at the site of osteotomy. The cage ears were molded on the tibial surface and fixed with 2.4 mm self-tapping cortical screws. At the moment of the cage attachment to the tibial tuberosity, orthopedic washers of 2 mm wide were placed between the cranial ears of the cage and the tibial tuberosity, thus promoting a lateral transposition of the tibial tuberosity. The patient was maintained in the early postoperative period with Robert Jones bandage, and with antibiotic, analgesic and anti-inflammatory drugs. On the second day after the procedure partial limb support with presence of mild lameness was observed. At three months postoperatively, the animal had no claudication and MPL was corrected. The radiographic examination showed the proper process of bone repair at the osteotomy site. In the clinical evaluation performed at one year after surgery the patient was in good condition without lameness and with proper limb support and muscular gain.Discussion: The studies that evaluated the association of tibial tuberosity transposition and tibial tuberosity advancement techniques (TTTA) for the simultaneous treatment of MPL and CCL rupture demonstrated that this is a viable and effective procedure. In this report, the accomplishment of tibial osteotomy based on the Maquet hole and the advancement of the tibial tuberosity with the TTA-Maquet cage-only allowed the dynamic stabilization of the CCL deficient stifle and the early use of the affected limb. In addition, the TTTA technique proved to be effective for the correction of grade 3 of MPL in a large dog, allowing adequate recovery of the limb function without complications during a one year evaluation period.

Biomechanical Comparison of Soft Tissue Reconstructions in the Treatment of Medial Patellar Luxation in Dogs

Biomechanical Comparison of Soft Tissue Reconstructions in the Treatment of Medial Patellar Luxation in Dogs

Distal femoral lateral closing wedge osteotomy as a component of comprehensive treatment of medial patellar luxation and distal femoral varus in dogs.

To describe a cohort of dogs with medial patellar luxation managed with a distal femoral lateral closing wedge ostectomy (DFO) as a component of comprehensive treatment, and to report radiographic and long-term clinical outcome of this technique. Medical records of dogs that had a lateral closing wedge DFO as part of management of medial patellar luxation at three veterinary teaching hospitals were reviewed. Surgical reports as well as the preoperative, postoperative, and follow-up radiographs were reviewed. The anatomical lateral distal femoral angle (aLDFA) was determined. Long-term clinical outcome was assessed by telephone interview with the owner. A lateral closing wedge DFO was performed on 66 limbs. The mean pre- and postoperative aLDFA was 107.6° ± 5.8° and 94.1° ± 4.2°, respectively. Cranial cruciate ligament disease was identified in 28/66 affected limbs. Tibial angular deformity, torsional deformity, or both was identified in nine of the 66 limbs. Ostectomy healing was confirmed radiographically in 51/66 limbs. The mean time to union was 73 ± 37 days. All patellae were in the normal position and stable. Complications included infection (2/51), fixation failure (1/51), delayed healing (2/51), and persistent lameness (1/51). In this cohort of cases, DFO was a highly successful and repeatable component of surgical treatment for dogs with medial patellar luxation associated with femoral varus. This study also provides more evidence of the high rate of concurrent cranial cruciate ligament disease in cases of medial patellar luxation complicated by femoral varus, and supports an association between stifle instability and medial patellar luxation.

Computed tomographic evaluation of femoral and tibial conformation in English Staffordshire Bull Terriers with and without congenital medial patellar luxation.

To compare hindlimb conformation of English Staffordshire Bull Terriers with and without medial patellar luxation using computed tomography. Hindlimb computed tomography (CT) was performed on six English Staffordshire Bull Terriers with grade II or III medial patellar luxation, and six without medial patellar luxation. Inclination angle, femoral condyle trochanteric angle, anteversion angle (AA), distal anteversion angle (DAA), proximal anteversion angle (PAA), femoral varus angle (FVA), tibial valgus angle (TVA), and tibial torsion angle (TTA) were measured. Student's T-test was conducted to compare normal limbs to limbs with medial patellar luxation, all limbs of dogs with medial patellar luxation to limbs of the control group, and medial patellar luxation affected limbs (normal limbs of unilaterally affected dogs excluded) to the control group. P-values less than 0.05 were considered significant. Two dogs with medial patellar luxation were only affected unilaterally. Limbs of English Staffordshire Bull Terriers with medial patellar luxation had significantly diminished AA and DAA, in addition to decreased TVA. These differences were similar regardless of how the unaffected limbs from affected dogs were treated in our analysis. Medial patellar luxation in this population of English Staffordshire Bull Terriers was characterized by a decrease in femoral anteversion, external rotation of the femoral diaphysis, and decreased tibial valgus. These findings may help inform clinical decision making when performing osteotomy for treatment of medial patellar luxation in this breed.

Erratum to: Computed tomographic evaluation of femoral and tibial conformation in English Staffordshire Bull Terriers with and without congenital medial patellar luxation.

Objective: To compare hindlimb conformation of English Staffordshire Bull Terriers with and without medial patellar luxation using computed tomography. Methods: Hindlimb computed tomography (CT) was performed on six English Staffordshire Bull Terriers with grade II or III medial patellar luxation, and six without medial patellar luxation. Inclination angle, femoral condyle trochanteric angle, anteversion angle (AA), distal anteversion angle (DAA), proximal anteversion angle (PAA), femoral varus angle (FVA), tibial valgus angle (TVA), and tibial torsion angle (TTA) were measured. Student’s T-test was conducted to compare normal limbs to limbs with medial patellar luxation, all limbs of dogs with medial patellar luxation to limbs of the control group, and medial patellar luxation affected limbs (normal limbs of unilaterally affected dogs excluded) to the control group. P-values less than 0.05 were considered significant. Results: Two dogs with medial patellar luxation were only affected unilaterally. Limbs of English Staffordshire Bull Terriers with medial patellar luxation had significantly diminished AA and DAA, in addition to decreased TVA. These differences were similar regardless of how the unaffected limbs from affected dogs were treated in our analysis. Discussion and conclusion: Medial patellar luxation in this population of English Staffordshire Bull Terriers was characterized by a decrease in femoral anteversion, external rotation of the femoral diaphysis, and decreased tibial valgus. These findings may help inform clinical decision making when performing osteotomy for treatment of medial patellar luxation in this breed.

3D-printing Bone Model for Surgical Planning of Corrective Osteotomy for Treatment of Medial Patellar Luxation in a Dog

3D-printing Bone Model for Surgical Planning of Corrective Osteotomy for Treatment of Medial Patellar Luxation in a Dog

Kite Shield-Shaped Wedge Recession for Treatment of Medial Patellar Luxation in Seven Small-Breed Dogs.

To document the trochlear depth (TD) and clinical outcome after kite shield-shaped wedge (K-wedge) recession trochleoplasty in toy-breed dogs with medial patellar luxation (MPL). Case series. Seven toy-breed dogs (<5 kg) with uni- or bilateral grades II-IV MPL (10 stifles). A K-wedge recession trochleoplasty was performed in all dogs in combination with other surgical procedures as treatment for MPL. The TD, the ratio of the proximal TD to patella thickness, and the presence of osteophytes were determined from computed tomography images taken pre-, and 1 and 12 months postoperative. Lameness scores and MPL grade were also recorded. The TD and the ratio of proximal TD to patella thickness increased significantly immediately postoperative and remained increased at 1 and 12 months postoperative. The osteophyte score was significantly higher at 12 months postoperative than preoperative. All dogs had a reduction in MPL grade and improvement in lameness postoperative. K-wedge recession trochleoplasty was successful in treating MPL in a series of toy-breed dogs and offers an alternate to other trochlear recession techniques.

Treatment of Medial Patellar Luxation by Placement of a Cortical Screw on the Medial Side of the Tibial Crest in a Dog

An 8 ㎏, 9-month-old castrated male Shiba Inu presented with a history of intermittent bilateral hind limb lameness. On examination, grade Ⅲ medial patellar luxation of the bilateral hind limbs was diagnosed. A novel surgical method involving relatively noninvasive tibial tuberosity transposition was used to restore normal alignment of the quadriceps mechanism. The procedure involved an incision on the medial cortical bone of the tibial tuberosity along the tibial crest and placement of a cortical screw on the medial side of the tibial crest to laterally transpose the tibial tuberosity. Lameness and patellar luxation of bilateral hind limbs were improved at a 3-month postoperative examination. This technique could be considered an effective treatment for medial patellar luxation in skeletal immature patients.

Evaluation of surgical treatment of medial patellar luxation in Pomeranian dogs

In a prospective study, the outcome of surgical correction of medial patellar luxation of 70 stifle joints in 55 Pomeranian dogs was evaluated. Trochlear block recession alone was performed in 46 stifle joints, or in combination with tibial tuberosity transposition in 24 stifle joints in cases with grade II, III or IV medial patellar luxation. Additional procedures were performed to restore lateral and medial retinacular function. The recurrence of patellar luxation and the degree of lameness were evaluated up to at least 16 weeks after surgery. The overall recurrence rate was 10%. The outcome of surgery was considered good for grade II luxation with a 100% success rate. Recurrent medial patellar luxation was diagnosed in approximately 11% of dogs with grade III and in 36% of dogs with grade IV luxation. The postoperative lameness score decreased significantly in comparison with the preoperative score at four weeks and thereafter until the end of the study.

Latero-distal transposition of the tibial crest in cases of medial patellar luxation with patella alta

Medial patellar luxation is defined as medial displacement of the patella from the trochlear groove. In dogs, medial luxations account for 75% of all patellar luxation cases, and are frequently associated with patella alta. Common surgical treatments for medial luxation are trochleoplasty and lateral transposition of the crest to drive the patella into the correct anatomical alignment. Postoperative complications for this procedure are estimated to be between 18-29% of cases, with up to 48% of complications involving reluxation. It was previously hypothesized that in cases of medial luxation involving patella alta, the addition of a distal component to the lateral tibial crest transposition will result in repositioning of the patella into its proper position in the trochlear groove, thus reducing the recurrence of luxation. We performed this modified procedure on 14 dogs (17 limbs) that were suffering from medial luxation combined with patella alta, and our results led to favourable clinical outcomes. This modified surgical procedure places the patella into a more normal proximo-distal anatomical position, is simple to perform, and may become common practice for surgical treatment of medial patellar luxation with an alta component.

Surgical treatment of medial patellar luxation without femoral trochlear groove deepening procedures in dogs: 91 cases (1998–2009)

To assess signalment, outcomes, and complications for dogs surgically treated for medial patellar luxation (MPL) with a combination of lateral retinacular imbrication and tibial crest transposition procedures without femoral trochlear groove deepening techniques, and to determine whether osteoarthritis progressed in these patients during the 8-week period following surgery. Retrospective case series. Animals-91 dogs. Medical records were reviewed for information on signalment, clinical history, unilateral versus bilateral disease, preoperative and postoperative MPL grades, duration of follow-up, and perioperative and postoperative complications. Radiographs obtained preoperatively and during 8-week follow-up examinations were reviewed and assigned degenerative joint disease (DJD) scores (range, 0 to 3). Data were analyzed to determine factors influencing outcomes. Kaplan-Meier curves were constructed for recurrence of MPL. Minor postoperative complications were reported for 31 of 91 (34.1%) dogs. Patellar reluxation occurred in 18 of 91 (19.8%) dogs. Reluxation or complications for which additional surgery was recommended developed in 6 of 91 (6.6%) dogs. At last clinical follow-up, 10 of 91 (11.0%) dogs had at least occasional lameness. No difference was revealed between preoperative and postoperative (8-week follow-up) radiographic DJD scores. Results of surgical treatment of MPL without femoral trochlear groove deepening procedures were comparable to those in studies of surgical treatment that included groove deepening procedures. Radiographic indices of DJD did not increase during the 8 weeks following surgery. These results suggest that trochlear groove deepening procedures are not always necessary, and patients that undergo these techniques should be carefully selected.

Tibial tuberosity transposition-advancement for treatment of medial patellar luxation and concomitant cranial cruciate ligament disease in the dog

To report surgical technique, morphometric effects and clinical outcomes for tibial tuberosity transposition-advancement (TTTA), sulcoplasty and para-patellar fascial imbrication for management of concomitant medial patellar luxation (MPL) and cranial cruciate ligament (CCL) disease in 32 dogs. Case series. A previous technique for tibial tuberosity advancement was modified to incorporate lateral and distal tibial tuberosity transposition. Preoperative, immediate, and six to eight week postoperative radiographs were reviewed with morphometry of a range of tibial and stifle anatomic parameters. Findings of sequential clinical examinations to six to 20 months postoperatively were recorded. Thirty-nine stifles were treated by surgery. Medial patellar luxation grade ranged from II to IV/IV. The CCL rupture was complete in 17/39 stifles, and incomplete in 22/39. Complications occurred in 11/39 stifles including MPL recurrence (n=4). Resolution of subjectively-assessed lameness occurred in 29/39 stifles at the six to eight week assessment. Resolution of lameness was eventually documented in 35/39 stifles (4/39 lost to follow-up), and was maintained at the six to 20 month reassessment where available. The TTTA induced relative patella baja in 31/39 stifles. Magnitude of actual tibial tuberosity advancement was lower than that predicted by cage size. Tibial tuberosity transposition-advancement is a potential treatment modality for concomitant CCL disease and MPL in the dog, but refinement of planning is required, while biomechanical and kinematic effects remain unknown.

Fracture of the lateral trochlear ridge after surgical stabilisation of medial patellar luxation

This report details the management of a dog with a fracture of the lateral trochlear ridge, which occurred as a postoperative complication following trochlear block recession and tibial tuberosity transposition for treatment of medial patellar luxation. To the authors' knowledge, this complication has not been previously reported.

Rotation of the femoral trochlea for treatment of medial patellar luxation in a dog

A crossbreed dog was presented with non-weight bearing on the right hindlimb and a semi-flexed stifle. Clinical examination and radiographic investigation showed a grade 3 medial patellar luxation, characterised by hypoplasia of the medial trochlear ridge. No other significant skeletal abnormalities were detected. A 180 degrees rotation of the femoral trochlea was the surgical technique chosen to treat the trochlear dysplasia, the aim being to move the normal lateral ridge to the medial side and thereby prevent patellar luxation. This technique was able to restore correct conformation of the femoral trochlea and preserve the integrity of the trochlear groove cartilage, thus potentially retarding the progression of degenerative joint disease. The dog recovered fully and postoperative radiographic examinations showed healing of the rotated trochlea with only mild signs of degenerative joint disease.