Intra-articular Fibrolipoma of the Stifle in a Dog.

A 12 yr old male castrated miniature Australian shepherd dog presented for surgical consultation of historical bilateral medial patellar luxations with a 3 mo history of an acute onset of a left pelvic limb lameness. Physical examination confirmed medial patellar luxations and a mass effect of the left stifle medially. Radiographs showed medial distension of the joint capsule by a soft tissue opacity. Fine-needle aspirate of the left stifle revealed a mesenchymal cell population. Left medial parapatellar stifle arthrotomy found a fatty mass, which was excised at its base. A benign fibrolipoma was diagnosed on histopathology, and the excision was expected to be curative. The owners reported immediate improvement of perceived comfort postoperatively. At 2 and 24 wk, the dog returned to a normal level of function. Lipomas of the stifle, although rare, should be considered as a differential for intra-articular masses causing lameness.

Evaluation of the quadriceps muscle length to femoral length ratio in small breed dogs with medial patellar luxation.

OBJECTIVE: To determine the quadriceps muscle length (QML) to femoral length (FL) ratio (QML/FL) and its associated factors in small breed dogs with medial patellar luxation (MPL) and to compare the differences in the QML/FL between MPL grades. STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Small breed dogs (<10 kg) with MPL: 78 dogs (134 limbs). METHODS: Medical records and computed tomography (CT) images from 2008-2020 were reviewed. Furthermore, age, bodyweight, sex, laterality, MPL grade, femoral inclination angle (FIA), femoral torsion angle (FTA), anatomical lateral distal femoral angle (aLDFA), and patellar ligament length to patellar length ratio were included in the regression analysis to determine the factors associated with QML/FL. Each measurement parameter was compared among the four MPL grade groups. RESULTS: The final model demonstrated that the QML/FL increased with increasing age (p = .004) and decreased with increasing FTA and aLDFA (p = .015 and p < .001, respectively). The MPL grade IV group had a lower QML/FL than the grade I, II, and III groups (p = .002, p < .001, and p < .001, respectively). CONCLUSION: Among small breed dogs, those with MPL grade IV had a shortened QML associated with femoral deformities. CLINICAL SIGNIFICANCE: Noninvasive evaluation of the QML/FL improves our understanding of the length mismatch between the quadriceps muscle and the femur.

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

OBJECTIVE: 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. STUDY DESIGN: Retrospective case series. SAMPLE POPULATION: Dogs (n = 235) undergoing MPL correction, using m-TTT (n = 300 stifles). METHODS: 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. RESULTS: 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. CONCLUSION: The m-TTT technique yielded acceptable complication rates, with high owner satisfaction. CLINICAL SIGNIFICANCE: The m-TTT should be considered as an alternative technique for treating dogs with MPL requiring a tibial tuberosity transposition.

Computed tomographic measurements of the femoral trochlea in dogs with and without medial patellar luxation.

OBJECTIVES: To determine cutoff values in small (SB) and medium/large (MLB) breed dogs with and without medial patellar luxation (MPL) for identifying abnormal femoral trochlea morphology. STUDY DESIGN: Original research. ANIMALS: A total of 80 computed tomographic (CT) scans from client-owned dogs METHODS: Four groups of 20 dogs were created: (1) control SB, (2) control MLB, (3) MPL-SB, and (4) MPL-MLB. Two authors measured the femoral trochlear groove angle (FTGA), femoral trochlear angle (FTA), and femoral trochlear ridge inclination angle (FTRIA) in two points with CT. ANOVA and ROC-analysis were tested to the control and MPL groups to assess sensitivity, specificity, and cutoff values. Statistical significance was set to p < .05. Intraclass correlation coefficients evaluated the inter-rater agreement. RESULTS: FTGA (± SD) in control SB (128.8° ± 4.7°) and control MLB (119.2° ± 5.6°), was smaller (p < .0001) than in MPL-SB (139.4° ± 4.4°) and MPL-MLB (133.7° ± 5.1°). FTA and FTRIA were decreased (p = .12, p = .23) in MPL-SB (2.1° ± 6.8; -0.3° ± 3.3°) and MPL-MLB (3.8° ± 5.6°; 1.7° ± 4.5°) compared to control SB (0.2° ±4.1; -0.1° ± 2.6°) and control MLB (5.3° ± 2.8°; 3.1° ± 1.3°). Cutoff values for FTGA, FTA, and FTRIA were > 134°, < -5.9°, < -2 ° (SB), and > 128.3°, < -0.4°, < -0.4° (MLB). Sensitivity, specificity, and inter-rater agreement were superior for FTGA than FTA and FTRIA. CONCLUSIONS: Dogs without MPL had a deeper femoral trochlear groove than MPL dogs. SB had a shallower groove than MLB. The measurement of FTA and FTRIA was not reliable. CLINICAL RELEVANCE: A FTGA <134° (SB) and < 128° (MLB) may be considered as a cutoff for trochleoplasty decision-making.

The value of routine radiographic follow up in the postoperative management of canine medial patellar luxation.

OBJECTIVE: To determine the influence of radiographic examination on the recommendations made at the time of planned re-evaluation of dogs after medial patellar luxation (MPL) surgery. STUDY DESIGN: Retrospective multi-institutional case series. ANIMALS: Client-owned dogs (N = 825) that underwent MPL surgery. METHODS: Records of 10 referral institutions were searched for dogs that had been treated surgically for unilateral MPL and underwent a planned follow-up visit, including radiographs. The frequency of, and reasons for, changes in further recovery recommendations were investigated. RESULTS: Follow up was performed at a median of 6 (range, 4-20) weeks postoperatively. Isolated radiographic abnormalities were identified in 3.3% (27/825) of dogs following MPL surgery and led to a change in recommendations in 3% (13/432) of dogs that were presented without owner or clinician concerns. Lameness, administration of analgesia at follow up, and history of unplanned visits prior to routine re-examination were associated with a change in postoperative plan (P < .001). In the absence of owner and clinician concerns, the odds of having a change in convalescence plans were not different, whether or not isolated radiographic abnormalities were present (P = .641). CONCLUSION: Routine radiographs at follow up did not influence postoperative management of most dogs after MPL surgery in the absence of abnormalities on clinical history or orthopedic examination. CLINICAL SIGNIFICANCE: Dogs that were presented for routine follow up after unilateral MPL surgery without owner concerns, lameness, analgesic treatment or a history of unplanned visits, and for which examination by a surgical specialist was unremarkable, were unlikely to benefit from radiographs.

Three-dimensional volume rendering planning, surgical treatment, and clinical outcomes for femoral and tibial detorsional osteotomies in dogs.

OBJECTIVES: To describe a computed tomographic (CT) methodology for planning the correction of femoral and tibial torsion and report the clinical outcomes after femoral (FDO) and tibial (TDO) detorsional osteotomy in dogs affected by torsion malalignment and patellar luxation (PL). STUDY DESIGN: Multicenter retrospective study. ANIMALS: Eighteen client-owned dogs. METHODS: Dogs underwent CT to measure femoral (FTA) and tibial torsion angle (TTA). Abnormal femoral external torsion was defined when FTA <20°, abnormal femoral internal torsion if FTA >35°; abnormal tibial external torsion was defined when TTA < -10°, and abnormal tibial internal torsion when TTA >2°. The cortical arch length (CAL) was measured with CT and used intraoperatively to determine the magnitude of correction. The medical records and radiographs were reviewed and used to report clinical and radiographic outcomes. Radiographs were reviewed to evaluate postoperative limb alignment, patellar position, and bone healing. RESULTS: Twenty-two detorsional osteotomies were performed. Mean preoperative FTA was 14° for medial-PL and 45.2° for lateral-PL. Mean preoperative TTA was 11° for medial-PL. Physiological patellar tracking was restored in 22/22 of cases. CAL measurement allowed for correction of abnormal torsion in 19/22 of cases. Seventeen out 18 dogs had full or acceptable functional outcome. The median radiographic follow-up was 3 months. Major complications occurred in 2/22 cases, which suffered an iatrogenic abnormal femoral internal torsion and a persistent hindlimb lameness. CONCLUSIONS: CAL can be measured with CT and used intraoperatively to guide the correction of abnormal torsion in dogs. CLINICAL RELEVANCE: Abnormal femoral and tibial torsion are predisposing factors for PL. A higher complication rate is expected when FDO and TDO are performed in the same hindlimb.

Three-dimensional motion of the patella in French bulldogs with and without medial patellar luxation.

BACKGROUND: French bulldogs exhibit significantly larger femoral external rotation and abduction than other breeds. We were curious as to whether this peculiar leg kinematic affects patellar motion and/or might induce medial patellar subluxation (MPSL) or medial patellar permanent luxation (MPPL). We hypothesized that the more abducted leg posture during stance causes an unusual medial pull direction of the rectus femoris muscle during stance, and that this may facilitate the occurrence of MPSL or even MPPL during locomotion. To test our hypothesis, we analyzed existing stifle-joint X-ray-sequences collected during the treadmill walk and trot of seven adult female French bulldogs. We estimated 3D-patellar kinematics using Scientific Rotoscoping. RESULTS: The three-dimensional motion of the patella comprises rotations and translations. From the seven dogs analyzed, three exhibited MPSL and one MPPL during the gait cycle. Medial patellar luxation (MPL) occurred mostly around toe-off in both gaits studied. Patellar position was generally not gait-related at the analyzed timepoints. In dogs with MPL, the patella was placed significantly more distally (p = 0.037) at touch-down (TD) and at midswing (p = 0.024), and significantly more medial at midswing (p = 0.045) compared to dogs without MPL. CONCLUSIONS: Medial patellar luxation seems to be the consequence of the far from parasagittal position of the stifle joint during stance due to a broad trunk, and a wide pelvis. This peculiar leg orientation leads to a medial sideway pull caused by the rectus femoris muscle and the quadriceps femoris and may initiate plastic deformation of the growing femur and tibia. Thus, a way to avoid MPL could be to control breeding by selecting dogs with lean bodies and narrow pelvis. Actual breeding control programs based on the orthopedic examination are susceptible to errors. Systematic errors arise from the fact that the grading system is highly dependent on the dog's condition and the veterinarians' ability to perform the palpation on the stifle. Based on our results, the position of the patella at TD, or even perhaps during stand might offer a possibility of an objective radioscopic diagnostic of the MPL.

Proximodistal and caudocranial position of the insertion of the patellar ligament on the tibial tuberosity and patellar ligament length of normal stifles and stifles with grade II medial patellar luxation in small-breed dogs.

OBJECTIVE: To assess the role of the proximodistal and caudocranial relative position of the patellar ligament insertion on the tibia and patellar ligament length-to-patellar length ratio (PLL:PL) in small-breed dogs with and without grade II medial patellar luxation (MPL). STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Dogs weighing ≤15 kg, including 43 stifles with MPL and 34 control stifles. METHODS: The proximodistal and caudocranial relative position of the patellar ligament insertion was determined as a ratio using the vertical (VTT) and horizontal distance (HTT) between the tibial tuberosity insertion and the tibial plateau divided by the tibial plateau length (TPL). In addition, PLL:PL and tibial plateau angle (TPA) were determined. RESULTS: The VTT:TPL ratio was lower in affected stifles (95% CI: 0.86-0.94) than in the control group (0.93-1.01; p = .01). No other difference was identified between affected and normal stifles. CONCLUSION: The only difference identified in this study consisted of a more proximal position of the patellar ligament insertion in the stifles of small-breed dogs with grade II MPL. CLINICAL SIGNIFICANCE: The more proximal position of the patellar ligament insertion will result in a more proximal position of the patella in the trochlear groove and may contribute to the development of MPL. Potentially, this will also affect the risk of recurrence of MPL after surgical treatment.

Transarticular elastic external skeletal fixator correction of a stifle rotational deformity and patellar luxation in a dog.

OBJECTIVE: To report the preoperative evaluation, treatment with transarticular elastic external skeletal fixation (ESF), and outcome of a dog with bilateral medial patellar luxation (MPL) and stifle rotational deformity. ANIMAL: One nonambulatory, 2.5-month-old, 7.5-kg mixed-breed intact female dog. STUDY DESIGN: Case report METHODS: Complex pelvic limb deformities were assessed with physical examination and computed tomography (CT) and characterized as bilateral grade 4 MPL and 90° internal rotation of the tibia in relation to the femur. Three-dimensional imaging and bone models were used to quantify the deformity and rehearse surgical correction. Transarticular elastic chains between ESF pins in the femur and tibia were used to gradually correct stifle rotational malalignment on each pelvic limb. Soft tissue releases, imbrication, and a transphyseal staple were used to correct the patellar luxation (PL) and femoral varus. The dog was reevaluated for 1 year postoperatively. RESULTS: Short- and long-term management included intensive physical rehabilitation to increase pelvic limb strength and function. Surgical treatment resulted in resolution of the PL and neutral stifle alignment. The dog was able to ambulate with persistent decreased range of motion of the stifle. CONCLUSION: Transarticular elastic chains and femoral physeal stapling improved the function of a dog with severe bone deformities and PL in a growing dog.

Biomechanical analysis of canine medial patellar luxation with femoral varus deformity using a computer model.

BACKGROUND: Femoral varus deformities complicating the realignment of the quadriceps muscles are frequently associated with medial patellar luxation (MPL) in dogs. Therefore, distal femoral osteotomy (DFO) is recommended in dogs affected with severe MPL and a distal femoral varus deformity. The presence of an anatomic lateral distal femoral angle (aLDFA) of ≥ 102° has been anecdotally recommended as an indication for performing corrective DFO in large-breed dogs. However, the effect of a femoral varus deformity on MPL has not been scientifically evaluated. We aimed to evaluate the influence of a femoral varus deformity on MPL using a finite element method based computer model. Three-dimensionally reconstructed computed tomographic images of a normal femur from a Beagle dog were deformed using meshing software to create distal varus deformities. A total of thirteen aLDFAs, including 95°, 98° and 100°-110°, were simulated. The patellar positions and reaction force between the patella and trochlear grooves were calculated for all finite element models under constant rectus femoris muscle activation. RESULTS: The patella was displaced medially from the trochlear groove at an aLDFA of ≥103°. With an aLDFA of 103° to 110°, the reaction force was equal to zero and then decreased to negative values during the simulation, while other models with aLDFAs of 95°, 98°, and 100°-102° had positive reaction force values. The patella began to luxate at 24.90 seconds (sec) with an aLDFA of 103°, 19.80 sec with an aLDFA of 104°, 21.40 sec with an aLDFA of 105°, 20.10 sec with an aLDFA of 106°, 18.60 sec with an aLDFA of 107°, 15.30 sec with an aLDFA of 108°, 16.60 sec with an aLDFA of 109°, and 11.90 sec with an aLDFA of 110°. CONCLUSION: Severe distal femoral varus with an aLDFA of ≥103° caused MPL when other anatomical factors were controlled. Thissimplified computer model provides complementary information to anecdotal cutoffs for DFO, hence it should be applied to clinical patients with caution.

Accuracy of patient-specific three-dimensional-printed osteotomy and reduction guides for distal femoral osteotomy in dogs with medial patella luxation.

OBJECTIVE: To compare precorrectional and postcorrectional femoral alignment following distal femoral osteotomy using patient-specific 3-dimensional (3D)-printed osteotomy and reduction guides in vivo and ex vivo. STUDY DESIGN: Prospective study. SAMPLE POPULATION: Ten client-owned dogs and matching 3D-printed plastic bone models. METHODS: Distal femoral osteotomy was performed via a standard approach using osteotomy and reduction guides developed with computer-aided design software prior to 3D-printing. Femoral osteotomy and reduction was also performed on 3D-printed models of each femur with identical reprinted guides. Femoral varus angle (FVA) and femoral torsion angle (FTA) were measured on postoperative computed tomographic images by 3 observers. RESULTS: In vivo, the mean difference between target and achieved postoperative was 2.29° (±2.29°, P = .0076) for the FVA, and 1.67° (±2.08°, P = .300) for the FTA. Ex vivo, the mean difference between target and achieved postoperative was 0.29° (±1.50°, P = .813) for the FVA, and -2.33° (±3.21°, P = .336) for the FTA. Intraobserver intraclass correlation coefficients (ICC; 0.736-0.998) and interobserver ICC (0.829 to 0.996) were consistent with an excellent agreement. CONCLUSION: Use of 3D-printed osteotomy and reduction guides allowed accurate correction of FTA in vivo and both FVA and FTA ex vivo. CLINICAL SIGNIFICANCE: Use of 3D-printed osteotomy and reduction guides may improve the accuracy of correction of femoral alignment but warrant further evaluation of surgical time, perioperative complications, and patient outcomes compared with conventional techniques.

Spontaneous resolution of bilateral congenital patellar luxation in an alpaca cria.

An 8-day-old alpaca was presented for suspected meconium impaction and abnormal gait and posture. Physical examination revealed bilateral medial patellar luxation. In previous reports, medical treatment of patellar luxation in crias has been associated with a poor to grave prognosis; here we report a case of successful resolution.

Résolution spontanée d'une luxation patellaire bilatérale congénitale chez un bébé alpaga. Un alpaga âgé de 8 jours a été présenté pour une impaction soupçonnée du méconium et une démarche et une posture anormales. L'examen physique a révélé une luxation patellaire médiale bilatérale. Dans des rapports antérieurs, le traitement médical de la luxation patellaire chez les bébés alpaga a été associé à un pronostic sombre ou grave; nous avons ici un rapport de cas d'une résolution réussie.(Traduit par Isabelle Vallières).

Major complications of tibial tuberosity advancement in 1613 dogs.

OBJECTIVES: To report major postoperative complications in 1613 dogs with tibial tuberosity advancement (TTA). STUDY DESIGN: Retrospective case series. SAMPLE POPULATION: Dogs (n = 1613) with cranial cruciate ligament deficiency treated with TTA. METHODS: Medical records of TTAs performed between December 2007-2013 were reviewed for age, sex, weight, contralateral stifle surgery, surgical approach, duration of preoperative lameness, presence of meniscal damage, concurrent patellar luxation and simultaneous bilateral TTA. Major postoperative complications were defined as surgical site infection (SSI) (superficial, deep, or organ/space), implant failure, fracture, patellar luxation, and meniscal tear. RESULTS: Major complications were recorded in 13.4% of cases. Superficial SSI (incisional irritation) was diagnosed in 6.9% cases, requiring only antimicrobial therapy. Other complications included postliminary medial meniscal tear (2% incidence), deep SSI (incisional dehiscence, 1.1%), implant failure (1%), patellar luxation (1.2%), fracture (0.9%), and organ/space SSI (septic arthritis, 0.4%). Dogs with normal menisci were less likely to develop postliminary meniscal tears if the medial meniscus was released at the time of TTA (P < .0001). No association was detected between recorded parameters and complications, although dogs >8 years old approached significance (P = .05) in terms of predisposition to major complications. CONCLUSIONS: Major complications after TTA are uncommon, even in dogs with concurrent patellar luxation or bilateral simultaneous procedures. In spite of its morbidity, medial meniscal release may prevent postliminary meniscal tears.

Comparison of complication rates of unilateral, staged bilateral, and single-session bilateral surgery for the treatment of bilateral medial patellar luxation in dogs.

This retrospective study compared complication rates in 93 client-owned dogs (119 stifles) undergoing single-session bilateral, staged bilateral, or unilateral surgery for bilateral medial patellar luxation. Clinical characteristics and complication rates were compared and risk factors for major complications were explored. Sixty-five dogs had unilateral, 16 staged bilateral and 11 single-session bilateral surgery. Complications occurred in 28/119 stifles (24%), 11 (9%) of which required revision surgery. Patellar reluxation occurred in 7/119 (6%) stifles, with no revision required. There was no significant association between timing of surgery and incidence of complications. In dogs < 10 kg with bilateral medial patellar luxation, single-session bilateral surgery is a feasible treatment option with a complication rate comparable to staged bilateral or unilateral medial patellar luxation surgery.

Comparaison des taux de complication de la chirurgie unilatérale, bilatérale à étage, et bilatérale à session unique pour le traitement de la luxation patellaire chez le chien. Cette étude rétrospective a comparé les taux de complications observés chez 93 chiens de propriétaires (119 genoux) subissant une chirurgie bilatérale simultanée, une chirurgie bilatérale en deux temps ou une chirurgie unilatérale pour luxation médiale de la rotule bilatérale. Les données cliniques et les taux de complications ont été comparés et les facteurs à risque de complications majeures ont été étudiés. 65 chiens ont subi un traitement unilatéral, 16 un traitement bilatéral en deux temps et 11 un traitement bilatéral simultané. Des complications sont survenues dans 28/119 grassets (24 %), dont 11 (9 %) ont nécessité une chirurgie de révision. Une reluxation de la rotule s'est produite dans 7/119 grassets (6 %), sans qu'une révision n'ait été nécessaire. Aucune association significative entre le planning chirurgical et l'apparition de complications n'a pu être mise en évidence. Chez les chiens < 10 kg souffrant de luxation médiale de la rotule bilatérale, une chirurgie bilatérale simultanée est une option thérapeutique valable, possédant un taux de complications comparable à celui de la chirurgie en deux temps ou seulement unilatérale.(Traduit par les auteurs).

Breeding implications resulting from classification of patellae luxation in dogs.

Patellar luxation (PL) is one of the major hereditary orthopaedic abnormalities observed in a variety of dog breeds. When the patellae move sideways out of the trochlear groove, this is called PL. The PL score varies between dogs from normal to very severe. Reducing the prevalence of PL by breeding could prevent surgery, thereby improve welfare. Orthopaedic specialists differentiate between normal and loose patellae, where the patellae can be moved to the edge of the trochlear groove, considering scoring loose patellae as normal in the future. Loose patellae are considered acceptable for breeding so far by the breeding organization. The aim of this study was to analyse the genetic background of PL to decide on the importance of loose patellae when breeding for healthy dogs. Data are available from two dog breeds, that is Flat-coated Retrievers (n = 3808) and Kooiker dogs (n = 794), with a total of 4602 dogs. Results show that loose patellae indicate that dogs are genetically more susceptible to develop PL because family members of the dogs with loose patellae showed more severe PL. In addition, the estimated breeding values for dogs with loose patellae indicate that breeding values of dogs with loose patellae were worse than breeding values obtained for dogs with a normal score. Given these results, it is advised to orthopaedic specialists to continue to score loose patellae as a separate class and to dog breeders to minimize the use of dogs in breeding with a genetically higher susceptibility for PL.

Postoperative Complications and Short-Term Outcome Following Single-Session Bilateral Corrective Surgery for Medial Patellar Luxation in Dogs Weighing <15 kg: 50 Cases (2009-2014).

OBJECTIVE: To assess complication rates and short-term outcome in small dogs with bilateral medial patellar luxation (MPL) undergoing single-session bilateral corrective surgery. STUDY DESIGN: Retrospective case series. ANIMALS: Dogs weighing <15 kg with congenital bilateral MPL that underwent single-session bilateral corrective surgery (n = 50). METHODS: Surgical procedures for MPL correction included trochlear wedge recession (TWR), crest transposition, lateral imbrication, and medial fascial release. Complication rates were correlated with number of surgical procedures, weight, whether or not a bandage was applied postoperatively, and surgeon experience (ACVS Diplomate vs resident). Results were compared with the most recent study evaluating single-session bilateral corrective surgery for MPL. RESULTS: Overall complication rate was 22% (11 of 50 dogs). Implant failure occurred in 2 dogs (3 stifles) requiring revision. Grade 1 patella reluxation was the most common minor complication at 10% (5/50). Overall complication and reluxation rates were similar to previous studies. There were no intraoperative complications after performing TWR in small dogs. CONCLUSION: Single-session bilateral corrective surgery for MPL is well tolerated in small dogs with complication rates historically similar to dogs undergoing unilateral or staged bilateral surgery. With individual case assessment, single-session surgery could be offered to owners, allowing one anesthetic episode and potentially lowering the chance for morbidity. Further studies, ideally prospective studies, are needed to assess long-term outcome following single-session bilateral corrective surgery for MPL.

Surgical Correction of Traumatic Lateral Patellar Luxation.

OBJECTIVE: To report successful surgical repair of a grade IV lateral patellar luxation in a 437-kg heifer. STUDY DESIGN: Case report. ANIMAL: Seventeen-month-old Holstein heifer (437 kg). METHODS: Diagnosis of traumatic lateral patellar luxation was made based on physical examination, and confirmed on radiographs. Arthroscopic examination of the stifle assessed joint changes. Lateral patellar luxation was surgically repaired using lateral release of the patella and medial imbrication of the joint capsule. RESULTS: The heifer presented nonweight-bearing lameness of the left hind limb (5/5 lameness score). Unilateral grade IV lateral patellar luxation was diagnosed based on physical examination and radiography. Arthroscopic examination of the stifle showed synovitis and cartilage eburnation of the medial articular surface of the patella and of the lateral trochlear ridge of the femur. Lateral release of the patella and medial imbrication of the joint capsule was performed. The heifer remained lame (4.5/5 lameness score) and developed severe disuse muscle atrophy after surgery. By day 112, the heifer was walking easily and was completely weight bearing on the left hindlimb but did have a gait alteration (2/5 lameness score). On day 229, the heifer calved for the first time and lameness was no longer evident. CONCLUSION: This report documents successful surgical treatment of traumatic lateral patellar luxation in a large heifer but additional case evaluation is required to provide an accurate prognosis for this condition and treatment in large cattle.

Clinical results of single-session bilateral medial patellar luxation repair in 26 small breed dogs.

Medical records of 26 small breed dogs treated with single-session bilateral medial patellar luxation repair were reviewed. Excluding dogs with complications associated with cranial cruciate ligament disease, 20/21 dogs with long-term follow-up achieved a complete or acceptable clinical recovery. The complication rate was not increased compared to that previously reported for unilateral patellar luxation repair.

Résultats cliniques de la réparation d'une luxation patellaire médiale bilatérale en une seule séance chez 26 chiens de petites races. Les dossiers médicaux de 26 chiens de petites races ayant subi la réparation d'une luxation patellaire médiale bilatérale en une seule séance ont été évalués. En excluant les chiens avec des complications associées à la maladie du ligament croisé antérieur, un rétablissement clinique complet ou acceptable a été observé chez 20/21 chiens lors d'un suivi à long terme. Le taux de complication n'a pas augmenté comparativement aux résultats antérieurement publiés pour la réparation d'une luxation patellaire unilatérale.(Traduit par Isabelle Vallières).

SURGICAL CORRECTION OF TRAUMATIC PATELLAR LUXATION IN AN EURASIAN LYNX (LYNX LYNX).

The aim of this report is to describe the successful surgical repair of a traumatic medial patellar luxation in a 4-yr-old female Eurasian lynx ( Lynx lynx ). The animal presented with hind limb lameness. Physical and radiographic examinations were performed under sedation. After diagnosing a medial patellar luxation, surgical repair was recommended. A combination of soft tissue reconstructive techniques was used to repair the medial patellar luxation. The limb was not immobilized postoperatively, but the animal was confined to a cage for 1 mo. The recovery was uneventful and return to normal activity was observed within 1 mo. Soft tissue reconstructive techniques can be used as the only surgical treatment for the repair of a traumatic patellar luxation in both domestic and wild animals.

[Intermittent upward fixation of the patella in 12 cows: A retrospective study of treatment and long-term prognosis]. / Patella-Fixation nach proximal bei 12 Kühen: Eine retrospektive Untersuchung zu Therapie und Langzeitprognose.

This retrospective study investigated possible risk factors for intermittent upward fixation of the patella and the outcome of medial patellar desmotomy in 12 cows. All but one young cow had distinctive clinical signs, which usually started in the periparturient period. Medial patellar desmotomy led to normalisation of the stride in 10 cows but did not improve the condition of the young cow. Another cow developed instability and signs of lateral patellar luxation in the affected stifle and was euthanized. The 10 cows that were operated successfully remained in the long term free of symptoms. Medial patellar desmotomy is a suitable treatment for upward patellar fixation in cattle but should be reserved for cows with typical clinical signs. The medial patellar ligament should be cut 4 to 6 cm proximal to its insertion on the tibia to minimise the risk of injury to the middle patellar ligament.