Diagnosis and surgical repair of patellar luxations in a flock of sheep

Eleven sheep with a common ancestry were evaluated for clinical signs of hind limb lameness. Physical examination revealed advanced forms of patellar luxation. Radiography confirmed the diagnosis of patellar luxation; flexed dorsoproximal-dorsodistal radiographic views were obtained and revealed hypoplasia of the femoral trochlea. Because of the advanced form of patellar luxation and trochlear hypoplasia, surgical intervention was recommended in the form of recession trochleoplasty and a modified tibial tuberosity transposition, along with imbrication and releasing incisions. Sheep may have a genetic predisposition for patellar luxation.     

Treatment of a congenital lateral patellar luxation by recession trochleoplasty in a donkey foal

The present report describes the surgical treatment of a congenital lateral patellar luxation in a 6-month-old female donkey foal. The foal was presented with a slight crouched position, muscle atrophy, moderate lameness, reluctance to flex the right hindlimb at a walk and slight effusion of the right stifle joint. The foal responded painfully to the stifle flexion test. Irreducible lateral luxation of the right patella was confirmed on physical examination and radiography. The animal was treated surgically by recession trochleoplasty and imbrication of the medial joint capsule. The animal gradually improved after surgery, and good clinical results were reported after 6 months post-operatively. In conclusion, congenital lateral luxation of the patella should be considered as a congenital cause of lameness in donkeys and surgical repair by recession trochleoplasty and medial imbrication of the joint capsule can be helpful to treat this problem.     

Rotating dome trochleoplasty: an experimental technique for correction of patellar luxation using a feline model.

The purpose of this study was to compare a trochlear block recession to a rotating dome trochleoplasty, a novel technique for the correction of patellar luxation in small animals. Twenty-eight limbs were used from 14 feline cadavers. With the stifles in flexion and extension, computed tomography was utilized to compare width and depth of the trochlea, medial trochlear ridge height, trochlear articular surface area preserved, patellar contact articular surface area, patellar area covered by the trochlear ridges and patellar tilt angle. The results of this study demonstrated that a rotating dome trochleoplasty is superior to a trochlear block recession with regard to medial trochlear height, trochlear width, trochlear depth and trochlear surface area preservation. The results of this study support further biomechanical evaluation of this technique which eventually may lead to clinical trials.     

Trochlear Block Recession in an Alpaca with Traumatic Lateral Patellar Luxation

Objective— To report surgical treatment of traumatic lateral patellar luxation using trochlear block recession in an alpaca.
Study Design— Clinical case report.
Animals— Five-year-old female alpaca.
Methods— Grade IV/IV lateral, left patella luxation and mild femoropatellar joint effusion was identified by palpation and visual assessment, and confirmed by ultrasonography and radiographs. Trochlear block recession combined with lateral retinacular release and medial imbrication to restore patella function.
Results— Progressive improvement in weight bearing occurred during hospitalization (6 days) and at 3.5 weeks, no lameness was observed; radiographically, the patella was in normal anatomic alignment. At 15 months, there were no signs of lameness with unrestricted exercise and the alpaca had given birth to another cria.
Conclusions— In this alpaca with traumatic origin of the lateral patellar luxation and normal femoro-tibial alignment, a combination of retinacular imbrication, contralateral release, and trochlear block recession were successful for long-term treatment of lateral patellar luxation.
Clinical Relevance— Although trochlear block recession is most commonly performed in small animals, this technique may be useful in treatment of traumatic patellar luxations in camelids.     

Clinical signs and results of treatment in cats with patellar luxation: 42 cases (1992-2002)

OBJECTIVE: To describe clinical signs and results of treatment in cats with patellar luxation. DESIGN: Retrospective case series. ANIMALS: 42 cats in which patellar luxation had been diagnosed on the basis of results of palpation of the stifle joints. PROCEDURES: Degree of luxation was graded on a scale from 1 to 4, and severity of lameness was graded on a scale from 0 to 5. Radiographs of stifle joints were evaluated for signs of osteoarthritis. Long-term function was classified as poor, fair, good, or excellent. RESULTS: 34 cats had bilateral luxation and 8 had unilateral luxation. Only 7 (17%) cats had a history of trauma. Mean age of the cats was 3.3 years, and mean weight was 4.26 kg (9.4 lb); 26 (62%) were domestic shorthairs. Seventy-three of the 76 (95%) affected joints had medial patellar luxation. Luxation grades could be assigned to 65 joints, with grade 2 (30 joints) and 3 (22 joints) luxation being most common. Lameness grades could be assigned to 73 joints, with grade 1 lameness (27 joints) most common. Outcome was excellent for 8 of 17 joints treated without surgery and for 23 of 35 joints treated surgically. Complications attributable to surgery were reported in 8 cats. CONCLUSIONS AND CLINICAL RELEVANCE: Patellar luxation should be considered as a cause of hind limb lameness in cats. Low-grade luxation can be associated with lameness of the same severity as high-grade luxation. Surgical correction of patellar luxation in cats with grade 2 or 3 lameness can result in a favorable outcome.     

SURGICAL MANAGEMENT OF A TRAUMATIC ELBOW LUXATION WITH CIRCUMFERENTIAL SUTURE PROSTHESES IN A RABBIT (ORYCTOLAGUS CUNICULUS)

A 2-year-old dwarf rabbit was referred for right forelimb lameness of 1-week duration. Physical examination and radiographic findings were consistent with an elbow luxation. Manual reduction under anesthesia was unsuccessful in correcting the luxated joint. A surgical approach was recommended to repair the rabbit elbow luxation. Transcondylar, transradial, and transulnar tunnels were drilled from lateral to medial with 2 suture prostheses being placed, 1 from the radius to the humerus and 1 from the humerus to the ulna. Analgesia was provided and the patient was reevaluated on days 2, 7, and 14 after the procedure. The luxation was reduced and no recurrence was noted a year following the surgical procedure. Circumferential suture prostheses, recently described with no reported postoperative complications in cats, can be used successfully in rabbits as evidenced in this case report.     

Patellar luxation in 70 large breed dogs

O bjectives : To report the signalment, history, clinical features, and outcome in dogs weighing greater than 15 kg, treated surgically and non-surgically for patellar luxation. Risk factors for the development of patellar luxation, postoperative complications, and outcome were evaluated.
M ethods : Details regarding signalment, bodyweight, breed, aetiology, unilateral or bilateral luxation, duration of lameness, grade of luxation, direction of luxation, grade of lameness at presentation, concomitant cranial cruciate ligament rupture, method of treatment, surgical technique, surgeon, and complications were obtained from the medical records. Outcome was graded as excellent, good, fair, or poor, according to the degree of lameness.
R esults : Seventy dogs (45 males and 25 females) were included. Thirty-five had bilateral luxations (105 limbs). Mean age was two years, and mean weight was 30 kg. The relative risk for Labrador retrievers was 3·3 (P<0·001). All luxations were developmental. Luxations were medial in 102 stifles and lateral in three. Fourteen stifles had concomitant cranial cruciate ligament rupture. As the grade of patellar luxation increased, so did the grade of lameness (P<0·001). Surgery was performed in 70 stifles, and outcome was excellent/good in 94 per cent and fair/poor in 6 per cent of stifles. Complications occurred in 29 per cent of stifles, and increasing bodyweight was found to be a risk factor (P=0·03). Thirty-five stifles were managed non-surgically, and outcome was excellent/good in 86 per cent and fair/poor in 14 per cent of stifles.
C linical S ignificance : In view of the potential risk of postoperative complications, all surgically treated cases of patellar luxation in large breed dogs should be managed with a femoral trochleoplasty, a tibial tuberosity transposition (stabilised with K-wires and a tension band wire), and soft tissue releasing and tightening procedures.     

Laterally luxating patella in a goat

A laterally luxating patella causing progressively worsening hind limb lameness was discovered in an 18-month-old cross-bred goat. The luxation was believed to be congenital in origin. Surgical correction was accomplished via subchondral trochlear sulcoplasty, capsular imbrication, and lateral relieving desmotomy. Surgical correction of an unusual orthopedic problem in goats can be accomplished by use of routine canine orthopedic techniques.     

Treatment of coxofemoral luxation in a mature Welsh pony by femoral head ostectomy: Long‐term outcome

A 233 kg, 4‐year‐old Welsh pony stallion presented with a unilateral coxofemoral luxation and a history of previous upward fixation of the patella. This condition was surgically managed by femoral head ostectomy using a craniodorsal approach to the luxated coxofemoral joint, without greater trochanteric osteotomy. Immediate improvement in weightbearing was observed after surgery and primary intention healing was recorded. Long‐term outcome, 4 years after surgery, was assessed by radiographic, ultrasonographic and lameness examination. The pony was in good body condition and the initial weight of this patient was restored. Despite fetlock hyperlaxity of the contralateral hindlimb, amyotrophy and mechanical lameness of the affected hindlimb, the pony showed evident comfort without apparent signs of pain and was able to trot and gallop. Bone callus was observed at imaging examination.     

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.     

Distal luxation of the patella in a horse

A 19-year-old Thoroughbred gelding presented with sudden onset, non-weight bearing lameness in the right hindlimb. Radiography confirmed distal luxation of the patella, which was replaced into its normal anatomical location under general anaesthesia. There were no pathological sequelae noted on follow-up examination 9 months after the initial injury. To our knowledge, this is a rare manifestation of patellar luxation, only reported once previously in the equine literature.     

Comparison of trochlear block recession and trochlear wedge recession for canine patellar luxation using a cadaver model

OBJECTIVE: To compare trochlear block recession (TBR) to trochlear wedge recession (TWR) with regards to patellar depth (percentage of patellar volume under the trochlear ridges), patellar articular contact, percentage of recessed trochlear surface area, and resistance to patellar luxation. STUDY DESIGN: In vitro computed tomography (CT) and biomechanical evaluation using a cadaver model. SAMPLE POPULATION: Twelve normal, large-breed canine cadavers. METHODS: Bilateral pelvic limb specimens with intact stifle joints were mounted on a positioning device. The femoral trochlear ridges were reduced to provide a standard shallow trochlea. TBR or TWR was performed to a standard depth randomly on paired specimens. CT and biomechanical evaluations were performed pre- and postoperatively in both an extended (148 degrees ) and flexed (113 degrees ) stifle position. CT images were digitized and measurements made using an image-analysis software program. Biomechanical testing consisted of applying 40 degrees of internal tibial rotation and documenting patellar luxation. RESULTS: The change in trochlear depth (depth of recession) was not significantly different between groups. In the extended stifle position (patella in the proximal trochlea), patellar depth and patellar articular contact with the recessed trochlea were significantly greater after TBR compared with TWR. The percentage of recessed trochlear surface area was significantly greater after TBR compared with TWR. In the extended position, a smaller percentage of the patellae luxated within 40 degrees of internal tibial rotation after TBR compared with TWR. CONCLUSIONS: TBR increases proximal patellar depth, increases patellar articular contact with the recessed proximal trochlea, recesses a larger percentage of trochlear surface area, and results in a greater resistance to patellar luxation in an extended position as compared with TWR. CLINICAL RELEVANCE: TBR may help limit the development of stifle DJD in dogs treated for canine patellar luxation.     

Facilitated ankylosis of a juvenile,flexurally deformed,open, luxated and infected metacarpophalangeal joint using an alternative approach

A 4‐day‐old Arabian filly was referred for severe lameness due to a flexurally deformed, open, luxated and infected metacarpophalangeal joint. Arthrodesis was indicated as progressive cartilage destruction and osteomyelitis developed. An alternative arthrodesis technique was employed, which consisted of a loop of cerclage wire running through predrilled holes in a lateromedial direction and dorsal to the central axis of the third metacarpal bone and proximal phalanx, in combination with external coaptation using a half‐limb transfixation cast. Ankylosis was radiographically confirmed after 4 weeks. The foal was discharged from the hospital with a grade 1 out of 5 lameness and a 6–7° valgus deviation of the ankylosed metacarpophalangeal joint. At telephone follow‐up after 18 months, the owner reported persistence of the valgus deviation, soundness at walk, and a slight gait irregularity at trot. The described cerclage wire arthrodesis technique is a relatively simple method for attaining ankylosis that could be considered in similar cases.     

A novel surgical treatment of type 3 congenital elbow luxation in a dog

Congenital luxation of the ulnar and radius is a rare orthopaedic condition in the dog. This case report describes a novel surgical treatment for congenital elbow luxation in a medium-breed dog. A 6-week-old Kelpie presented for left forelimb lameness and deformity. Radiographs and computed tomography (CT) confirmed the diagnosis of unilateral ulnar and radius luxation. The surgical repair involved open reduction followed by fixation with an extraarticular pin and a transarticular external fixator. The outcome of surgery was improved leg function and weight-bearing, however, reluxation of the radial head was diagnosed 7 weeks following surgery. This technique may offer an alternative surgical option to improve clinical signs, as well as insight into improving the management of this condition.     

Surgical treatment of tarsometatarsal joint luxation in a miniature horse foal

A 2-week-old Miniature Horse foal was referred for evaluation and treatment of a luxated right tarsometatarsal joint. Treatment consisted of closed reduction and internal fixation using two partially threaded Steinmann pins placed in normograde fashion through the tuber calcis into the proximal third metatarsus. Traumatic luxation has been reported to occur in the tarsocrural, proximal intertarsal and tarsometatarsal joints within the equine tarsus. Treatment for luxation of the distal intertarsal joint has not been documented. The treatment method most commonly suggested for tarsal luxation is closed reduction and cast immobilisation. Internal fixation using lag screws and plating has also been described. A combination of internal fixation and external coaptation is thought to achieve maximal stability and allow faster convalescence in cases of tarsal luxation. This case report describes for the first time a technique using two Steinmann pins to achieve successful internal fixation of a traumatic tarsometatarsal joint luxation in a 2-week-old Miniature Horse foal.     

Traumatic elbow luxation in 14 dogs and 11 cats

Objective To report the presentation and treatment of traumatic elbow luxation and to evaluate success following closed or open reduction. Design Retrospective case series conducted between April 1999 and April 2009. Methods Records of 14 dogs and 11 cats were reviewed for signalment, history, radiographic findings and treatment; 14 owners were contacted via phone questionnaire to assess for limb function following treatment. Fisher's two‐tailed P test was used to evaluate potential risk factors for lameness. Results The majority of luxations were caused by car accident and 96% of the cases luxated in a lateral direction. Closed reduction was successful in all cats and 11 dogs; 3 dogs required open reduction. Owners rated the animals' limb function as excellent (71%), good (7%), fair (22%) or poor (0%). All cats were rated excellent. An excellent result following closed reduction was achieved in 67% of canine cases. All cases of open reduction achieved fair results. All owners were satisfied with the outcome. No risk factors were significantly associated with post‐reduction lameness. Conclusions Elbow joints with good stability following closed reduction have a favourable outcome. Poor stability following closed reduction is an indication for surgery. Results suggest that cats tolerate elbow luxation better than dogs.     

Acetabular component orientation as an indicator of implant luxation in cemented total hip arthroplasty

OBJECTIVE: To determine the sensitivity and specificity with which acetabular component angles of inclination and version could be used, alone or in combination, to predict luxation of cemented total hip arthroplasties (THA). STUDY DESIGN: Comparison of retrospectively selected cases and controls SAMPLE POPULATION: All THA performed at the University of Florida between 1991 and 1998 with the BioMedtrix system and for which at least 2 months of radiographic follow-up were available. All THA performed at the University of Georgia with the BioMedtrix system which subsequently luxated. METHODS: Acetabular component inclination angle (IA) and acetabular version angle (VA) were determined for each THA. Data were grouped according to outcome - luxation or no luxation - with the luxated cases from the 2 institutions pooled. Receiver operator characteristic (ROC) analysis was used to evaluate decision rules for using IA and VA as tests for detecting postoperative luxation. Sensitivity and specificity for luxation and 95% confidence bounds were computed with selected values of IA and VA as cut-points. RESULTS: The nonluxation group consisted of 68 THA with a median follow-up time of 5 months (range, 2-60 months). The luxation group consisted of 12 THA with a mean time to luxation of 36 days. The nonluxation group had a mean +/- standard deviation (SD) IA and VA of 40.3 degrees +/- 8.9 degrees and 71.1 +/- 13.6 degrees, respectively, whereas the luxation group had a mean +/- SD IA and VA of 34.7 degrees +/- 12.6 degrees and 72.9 degrees +/- 16.6 degrees, respectively. An IA cut-point of 37.8 degrees achieved 58.3% sensitivity and 57.4% specificity. A VA cut-point of 73 degrees achieved 75.0% sensitivity and 51.5% specificity. IA and VA considered simultaneously achieved a 50.0% sensitivity and 88.2% specificity. CONCLUSIONS AND CLINICAL RELEVANCE: ROC analysis indicated that both IA and VA considered individually or simultaneously were poor indicators of luxation. Although extreme values of IA may predict luxation with high specificity, the potential for luxation cannot be excluded based on apparently appropriate values of IA and VA. The results of this study also indicate that a successful outcome is possible with a wide range of acetabular component positions.     

Total Hip Replacement in an Alpaca Using a Cementless Implant

Objective— To report use of a cementless total hip prosthesis in an alpaca.
Study Design— Case report.
Animals— Alpaca (n=1) with chronic craniodorsal coxofemoral luxation.
Methods— A 2.5-year-old Suri alpaca, 3 months pregnant, was admitted for evaluation of acute onset severe left hind limb lameness (grade 4/5) of 6 weeks duration. After diagnosis of craniodorsal luxation of the left femoral head, total hip replacement (THR) using a cementless implant was performed because of the poor prognosis for reduction of a chronic luxation.
Results— A press-fit prosthesis was used and the alpaca delivered a live cria 8 months later. Persistent mild mechanical lameness remained after surgery, with moderate reduction in mobility of the coxofemoral joint. The prosthesis was stable and correctly positioned at 7 weeks and at 9 months. There was mild exostosis surrounding the proximal aspect of the femur at 9 months, and Steinmann pins used to repair the trochanteric osteotomy were removed because of migration. At 1 year, the alpaca has a slight gait abnormality, remains with the herd on pasture and has been re-bred.
Conclusion— Chronic coxofemoral luxation in an alpaca can be managed by THR.
Clinical Relevance— THR is a viable treatment option in alpacas with severe coxofemoral disease.     

Surgical repair of coxofemoral luxation in a horse.

A 4-year-old castrated male Miniature Horse was evaluated because of severe right hind limb lameness of 5 days' duration. The diagnosis of craniodorsal luxation of the right coxofemoral joint was made by physical examination and radiographic imaging. Closed reduction was attempted but was unsuccessful. Surgical reduction was successfully performed, using toggle pin, synthetic capsular reconstruction, and trochanteric transposition techniques. No postoperative complications were observed. Follow-up 26 months after surgery revealed no recurrence of the luxation and no evidence of lameness. These surgical techniques are used successfully for repair of coxofemoral luxations in small animals. To our knowledge, there has been no report of these techniques attempted in horses. These surgical techniques may have merit for the treatment of coxofemoral luxations in small equine patients.     

Extended proximal trochleoplasty for the correction of bidirectional patellar luxation in seven Pomeranian dogs

Seven Pomeranians with bidirectional patellar luxation (BPL) were prospectively studied regarding aetiology and results of a new surgical technique. Radiographic evaluation of the ratio between patellar ligament length and patellar bone length revealed no differences between Pomeranians with bidirectional patellar luxation and healthy stifle joints. Functional rather than anatomic patella alta might be associated with bidirectional patellar luxation in Pomeranians. The surgical outcome of extended proximal trochleoplasty was good‐to‐excellent in 87·5% of the stifles and all dogs achieved functional recovery. There was only minimal radiographic progression of osteophyte formation at 48 weeks after surgery. To the authors’ knowledge, this is the first report on bidirectional patellar luxation in small breed dogs and its successful surgical treatment.