Comparison of three radiographic assessment methods for detecting slipped capital femoral epiphyses in cats: Klein's line, modified Klein's line and the S-sign.

OBJECTIVES: The aim of the present study was to investigate whether diagnostic assessment methods used on radiographs in humans with slipped capital femoral epiphysis (SCFE) can be used in cats. METHODS: The ventrodorsal (VD) extended-leg and VD frog-leg pelvic radiographs of 20 cats with SCFE without fully displaced femoral capital epiphyses (FCE), eight cats with fully displaced FCE and five control cats with normal pelvic anatomy were assessed by five observers on two separate occasions 3 months apart. The Klein's line and modified Klein's line were assessed on each VD extended-leg radiograph, and the S-sign was assessed on each VD extended-leg and VD frog-leg radiograph. RESULTS: Excluding cases of fully displaced FCE, the S-sign on the VD frog-leg radiographs more accurately diagnosed SCFE than the S-sign on the VD extended-leg radiographs and the Klein's line (92.4% vs 88.8% vs 60.6%, respectively), and had the greatest sensitivity (93.9% vs 79.2% vs 30.6%, respectively). The S-sign on the VD extended-leg radiographs had greater specificity than the Klein's line and S-sign on the VD frog-leg radiographs (99.2% vs 97.9% vs 90.9%, respectively). The modified Klein's line detected SCFE in 40.2% of cases that were negative for the Klein's line. CONCLUSIONS AND RELEVANCE: The S-sign in both VD extended-leg and VD frog-leg views successfully detected SCFE in cats and can be used to increase early diagnosis and treatment in cats with SCFE that have only subtle radiographic changes.

Do owner-reported changes in mobility reflect measures of activity, pain and degenerative joint disease in cats?

OBJECTIVES: The aim of this blinded, nested case-control study was to compare cats with and without early owner-reported mobility changes using subjective and objective outcome measures (owner-completed questionnaires, orthopaedic examination). METHODS: A total of 57 cats with and without early owner-reported signs of impaired mobility were allocated to the case (n = 30) and control (n = 27) groups, respectively. Participating owners completed one inclusion and two pre-visit questionnaires (Feline Musculoskeletal Pain Index, VetMetrica). Cats were then visited in their own homes, where they underwent an orthopaedic examination, an assessment of their body condition score and temperament, and the placement of an accelerometer on their collar for 2 weeks. RESULTS: There was no significant difference between groups for age category, breed, sex, temperament and body condition score. Case cats scored significantly lower for the Feline Musculoskeletal Pain Index (P = 0.003) and the VetMetrica domain of Comfort (P = 0.002), but not Vitality (P = 0.009) or Emotional Wellbeing (P = 0.018). Total pain (P <0.0001), crepitus (P = 0.002) and thickening (P = 0.003) scores were higher in case cats, as was the presence of bilateral disease (P = 0.005, odds ratio 14) and the number of bilaterally affected joints (P = 0.001). CONCLUSIONS AND RELEVANCE: Both the Feline Musculoskeletal Pain Index and orthopaedic examination were able to differentiate cats with early owner-reported signs of impaired mobility from healthy cats. VetMetrica Comfort domain scores indicated a compromised quality of life for cats with early owner-reported signs of impaired mobility compared with healthy cats. Being able to recognise signs of mobility impairment earlier would allow interventions aimed at slowing disease progression, thereby improving feline health and welfare.

Humeral condylar fractures and fissures in the French bulldog.

OBJECTIVE: To report the configuration, risk factors, fixation methods and complication rates after repair of humeral condylar fractures (HCF) in French bulldogs, and report the presence of humeral intracondylar fissures (HIF) in this population as a possible predisposing factor. STUDY DESIGN: Retrospective clinical cohort study. SAMPLE POPULATION: Forty-four elbows. METHODS: The medical records of dogs referred between January 2012 and December 2021 were searched for French bulldogs presenting with HCF. Signalment, fracture configuration, stabilization method and complication occurrence were obtained. Postoperative radiographs were assessed for implant positioning, and computed tomography (CT) scans were assessed for the presence and size of HIF in the contralateral elbow. RESULTS: Lateral humeral condylar fractures represented 28/44 (63.6%) of HCF in French bulldogs. Repair with a transcondylar screw (TCS) and Kirschner-wire(s) (K-wire) were 7.62 times more likely to result in a major complication (95% CI: 1.43, 21.89; p = .01) compared to other methods. All incidences (7/7) of TCS migration were within the TCS + K-wire group. A HIF was identified in 18/31 (58.1%) dogs. Older animals were not significantly less likely to have a HIF than younger animals (p = .129). CONCLUSIONS: Fracture stabilization with a TCS and K-wire(s) was associated with an increased risk of major complications and migration of the TCS. A HIF was present in the contralateral elbow of over half of the French bulldogs where CT was available. CLINICAL SIGNIFICANCE: A HIF may be a predisposing factor of HCF in French bulldogs. Alternative methods of stabilization to a TCS and K-wire(s) should be used to reduce complication risk.

Analysis of feline humeral fracture morphology and a comparison of fracture repair stabilisation methods: 101 cases (2009-2020).

OBJECTIVES: The aims of this study were to describe the type, presentation and prognostic factors of feline humeral fractures over a 10-year period and to compare three stabilisation systems for feline humeral diaphyseal fractures. METHODS: In total, 101 cats with humeral fractures presenting to seven UK referral centres between 2009 and 2020 were reviewed. Data collected included signalment, weight at the time of surgery, fracture aetiology, preoperative presentation, fixation method, surgical details, perioperative management and follow-up examinations. Of these cases, 57 cats with humeral diaphyseal fractures stabilised using three different fixation methods were compared, with outcome parameters including the time to radiographic healing, time to function and complication rate. RESULTS: The majority of the fractures were diaphyseal (71%), with only 10% condylar. Of the known causes of fracture, road traffic accidents (RTAs) were the most common. Neutered males were over-represented in having a fracture caused by an RTA (P = 0.001) and diaphyseal fractures were significantly more likely to result from an RTA (P = 0.01). Body weight had a positive correlation (r = 0.398) with time to radiographic healing and time to acceptable function (r = 0.315), and was significant (P = 0.014 and P = 0.037, respectively). Of the 57 humeral diaphyseal fractures; 16 (28%) were stabilised using a plate-rod construct, 31 (54%) using external skeletal fixation and 10 (18%) using bone plating and screws only. Open diaphyseal fractures were associated with more minor complications (P = 0.048). There was a significant difference between fixation groups in terms of overall complication rate between groups (P = 0.012). There was no significant difference between fixation groups in time to radiographic union (P = 0.145) or time to acceptable function (P = 0.306). CONCLUSIONS AND RELEVANCE: All three fixation systems were successful in healing a wide variety of humeral diaphyseal fractures. There was a significantly higher overall complication rate with external skeletal fixators compared with bone plating; however, the clinical impact of these is likely low.

Patellar fractures in cats: Repair techniques and treatment decision-making.

PRACTICAL RELEVANCE: While feline patellar fractures are not commonly encountered in practice, they tend to be found more often in younger cats; no breed or sex predispositions are recognised. If there is no evidence of a traumatic aetiology, the cat may be suspected of having patellar fracture and dental anomaly syndrome (PADS). Patellar fractures are easy to diagnose on lateral radiographs and there are several different fracture types. The type of fracture, the age of the cat at fracture occurrence and whether there is suspicion of a pathological aetiology are all relevant when considering treatment technique. CLINICAL CHALLENGES: While some cats with patellar fractures will do well with conservative management, surgical treatment is often indicated and decision-making can be challenging. EVIDENCE BASE: Information and recommendations provided in this review are based on the literature and the author's own clinical experience. There are several publications on PADS, but there is limited evidence as to what the underlying cause of this condition is, and the best method for managing patellar fractures is still an area where more research is needed. AIM: This review aims to gather the papers, case series and case reports published over the past few decades in order to discuss how best to manage different types of patellar fractures.

Chronic paronychia in cats with patellar fracture and dental anomaly syndrome.

CASE SERIES SUMMARY: The aim of this case series was to describe the clinical features and treatment of paronychia in cats diagnosed with patellar fracture and dental anomaly syndrome (PADS). Clinical records, photographs, microbiology, cytology and histopathology reports were collected, and follow-up was obtained. Five cats with paronychia were included. All five cats had multiple digits of multiple limbs affected and eventually underwent amputation of the third phalanx of one or multiple digits. A total of 36 digits were affected, 17% (n = 6/36) resolved with medical management and 83% (n = 30/36) were eventually treated successfully by amputation. The cats had treatment with numerous courses of antibiotics (range 7-20; mean 11 courses) over periods of time ranging from 10 to 67 months (mean 32 months). RELEVANCE AND NOVEL INFORMATION: Chronic paronychia may be an additional clinical feature of PADS and the probable mechanism involves poor integrity of osteopetrotic bone, loss of normal nailbed anatomy and secondary osteomyelitis of the distal phalanx. Medical management with antibiotics, anti-inflammatory therapy and steroid treatment may improve the clinical signs in the short term; however, in severe instances, amputation of the third phalanx of the affected digit seems to be necessary to resolve repeated recurrences and discomfort. Additional information on the long-term outcome is required. In any cat with atraumatic patellar fractures and/or retained deciduous teeth, paronychia may require surgical management if medical management is unsuccessful.

Associations between early neutering, obesity, outdoor access, trauma and feline degenerative joint disease.

OBJECTIVES: The aim of this case-control study was to identify early-life risk factors associated with the occurrence of owner-reported mobility changes in 6-year-old cats by examining prospective data from a longitudinal cohort study of pet cats, the Bristol Cats study. METHODS: Data on potential risk factors were obtained from seven sequential questionnaires completed between the ages of 2-4 months and 5 years. Mobility-related questions from the study questionnaire distributed at the age of 6 years were used to calculate each cat's mobility score. Cats with mobility scores of ⩾2 and 0 were allocated to the case and control groups, respectively, and the cat's status was the outcome variable. RESULTS: Of the 799 cats included for analysis, 238 (29.8%) had owner-reported mobility changes. Binomial logistic regression using backwards elimination identified four risk factors for owner-reported mobility changes at 6 years of age: entire neuter status at 6 months of age (odds ratio [OR] 1.97; 95% confidence interval [CI] 1.26-3.07), sustained trauma before 6 years of age (OR 1.85; 95% CI 1.30-2.60), outdoor access at 6 years of age (OR 1.67; 95% CI 0.96-2.90) and overweight/obese status at 6 years of age (OR 1.62; 95% CI 1.13-2.33). CONCLUSIONS AND RELEVANCE: Risk factor analysis demonstrated that obesity, outdoor access and a history of trauma may predispose cats to developing owner-reported mobility changes associated with degenerative joint disease, whereas neutering before 6 months of age appears to decrease that risk.

Treatment of pelvic fractures in cats with patellar fracture and dental anomaly syndrome.

OBJECTIVES: The aim of this study was to describe the treatment and outcome of acetabular and other pelvic fractures in cats with patellar fracture and dental anomaly syndrome (PADS) and to provide advice on how to manage these cases in practice. METHODS: Data were collated on cats with PADS that were reported to have sustained pelvic fractures or had fractures or fissures of the pelvis identified on submitted radiographs. The details of the fractures were recorded, in addition to any treatment and outcome information. RESULTS: Of the 215 cases reported with PADS, 58 cats (27%) were found to have pelvic fractures, none of which were known to have resulted from significant trauma. There were 101 fractures in total and of these 15 were treated with surgery, including 10 acetabular fractures, two ilial, two pubic and one ischial fracture. Screw loosening and loss of fracture reduction was seen in four of the surgically treated fractures (two pubic fractures, one ilial and one acetabular fracture). Fourteen cats were euthanased as a direct result of a fracture occurring. While most pelvic fractures healed uneventfully, some cats remained intermittently lame, but it was not always possible to determine the cause of the lameness from the information available and because all cats had concurrent patellar fractures. CONCLUSIONS AND RELEVANCE: Many of the pelvic fractures healed with conservative management. Fractures involving articular surfaces such as acetabular fractures may benefit from surgical stabilisation as surgery may offer the benefits of articular fracture repair with improved joint congruency and a faster return to normal activity.

Treatment of humeral condylar fractures and humeral intracondylar fissures in cats with patellar fracture and dental anomaly syndrome.

OBJECTIVES: The aim of this study is to describe the treatment and outcome of humeral condylar fractures and humeral intracondylar fissures in cats with patellar fracture and dental anomaly syndrome (PADS) and to provide advice on how to manage these cases in practice. METHODS: Data were collated on cats with PADS that were reported to have sustained humeral fractures or had fractures or fissures of the humerus identified on radiographs. The details of the fractures were recorded in addition to any treatment and outcome information. RESULTS: Of the 207 cases reported with PADS, 18 cats (8.7%) were found to have humeral condylar fractures, none of which was known to have resulted from significant trauma. Where treatment occurred, it involved the placement of transcondylar positional or lag screws. In some cases additional implants, including supracondylar bone plates and screws or Kirschner wires (K-wires), were used. Follow-up data revealed that only two cats were euthanased owing to the presence of the humeral fractures, with at least eight achieving some degree of recovery of function. CONCLUSIONS AND RELEVANCE: These humeral fractures all have the characteristics of stress insufficiency fractures, being simple isolated fractures that are short oblique, with increased radio-density at the fracture line and occurring following minimal or no trauma. Humeral intracondylar fissures were identified in two cats and it is possible that some of the other fractures may have occurred secondary to pre-existing fissures. To our knowledge, no prior reports exist of fissures in cats that do not meet the criteria for PADS. Surgical repair primarily consisted of the placement of transcondylar lag or positional screws with, in some cases, adjunct implants such as bone plates and screws or K-wires. Though there were insufficient data to determine the prognosis for these fractures in the long term, unlike patellar fractures, many of these fractures will heal if treated appropriately.

Skull pathology in 10 cats with patellar fracture and dental anomaly syndrome.

CASE SERIES SUMMARY: The aim of this case series is to describe the clinical and radiological features of mandibular and maxillary abnormalities in cats diagnosed with patellar fractures and dental anomalies, a condition that we have named 'patellar fracture and dental anomaly syndrome' (PADS), also known previously as 'knees and teeth syndrome'. Where available, clinical records, skull and/or intraoral dental radiographs, head CT images, microbiology and histopathology reports were collected, and follow-up was obtained. Ten cats with mandibular or maxillary abnormalities were identified. Common clinical features included multiple persistent deciduous teeth, gingivitis and swellings of the jaw. Skull radiographs were available for 7/10 cats and head CT images were available for one cat. Findings included marked bony and periosteal proliferation, hypodontia, root resorption, root malformation and unerupted permanent teeth. Where available, microbiology and histopathology results were consistent with osteomyelitis. RELEVANCE AND NOVEL INFORMATION: Mandibular and maxillary abnormalities are an additional unreported clinical feature of the rare condition that we have termed PADS. Radiologically, these lesions can have an aggressive appearance, which can mimic neoplasia. Medical management with antibiotic and anti-inflammatory therapy improves clinical signs in the short term; however, surgical extraction of persistent deciduous and unerupted permanent teeth, and debridement of proliferative and necrotic bone appear to be necessary for an improved outcome. Additional information on long-term outcome is required.

Incidence and types of preceding and subsequent fractures in cats with patellar fracture and dental anomaly syndrome.

OBJECTIVES: The aim of this study was to document the incidence of preceding and subsequent fractures to the patellar fractures in cats with patellar fractures and dental anomaly syndrome. METHODS: Records of cats with patellar fracture and dental anomaly syndrome were retrieved from the combined databases at the University of Bristol, UK, and Exclusively Cats Veterinary Hospital, USA. A request was made to complete a questionnaire to obtain long-term follow-up of these cats with respect to their current status and fractures to other bones; radiographs and histories were requested and were reviewed for treatment of ongoing fractures and outcome. RESULTS: Of the 191 cases reported with this syndrome, 92 cats (48.2%) had dental anomalies and 78 (40.8%) had fractures to other bones; 21 cats sustained the fractures preceding the patellar fractures and 57 subsequently. In total, there were 175 fractures: acetabulum (25%), tibia (22%), ischium (15.4%), humeral condyle (13.7%), calcaneus (5.1%), ilium (5.1%), pubis (3.4%) and other bones (10.2%). The majority of these fractures were characteristic of insufficiency (stress) fractures with a very similar configuration in each bone. CONCLUSIONS AND RELEVANCE: A high proportion of cats with patellar fracture and dental anomaly syndrome will have preceding or subsequent fractures to their patellar fractures. In this study, >10% of cats suffered characteristic fractures preceding the patellar fractures. The presence of these fractures should alert the veterinarian to the possibility that the cat is affected by patellar fracture and dental anomaly syndrome.

Open-mouth jaw locking in cats: a literature review and use of CT in three cases.

CASE SERIES SUMMARY: This report summarises and reviews the published cases of open-mouth jaw locking in cats and describes three further cases. Case 1 was a 5-year-old, 5.3 kg male neutered domestic shorthair cat. CT identified changes consistent with temporomandibular joint (TMJ) dysplasia with osseous degenerative changes, and the cat subsequently underwent bilateral partial zygomectomy with bilateral partial coronoidectomy. Case 2 was a 10-year-old, 6.0 kg male neutered Exotic Shorthair. Aside from a fracture of the left maxillary canine tooth crown and absence of the left maxillary fourth premolar tooth, no abnormalities were found on CT scan. The cat also underwent bilateral partial zygomectomy with bilateral partial coronoidectomy. The third case was a 1-year-old, 4.0 kg male neutered Persian cat. Changes on CT were consistent with bilateral TMJ dysplasia, and the cat underwent staged bilateral partial zygomectomy with bilateral partial coronoidectomy. There was no recurrence of open-mouth jaw locking in any of the cases on long-term follow-up. RELEVANCE AND NOVEL INFORMATION: Open-mouth jaw locking has been reported in cats of a wide range of ages, from 1-10 years. Cats with all skull types (brachycephalic, mesaticephalic and dolichocephalic) may be affected, but brachycephalic breeds seem to be over-represented. A CT scan with the jaw locked in place is recommended for diagnosis and surgical planning purposes; two of the cases reported here document the first cases of TMJ dysplasia in cats to be definitively diagnosed using CT. Trauma and symphyseal or TMJ laxity may also predispose to development of the condition. Partial coronoidectomy and partial zygomatic arch resection performed alone or in combination are generally successful at preventing recurrence. Bilateral partial zygomectomy with bilateral partial coronoidectomy has not previously been reported as a surgical treatment, and is recommended when open-mouth jaw locking occurs bilaterally.

Complications and outcomes associated with 13 cases of triceps tendon disruption in dogs and cats (2003-2014).

This study reports data from a larger number of cases of triceps tendon disruption. Records from 10 veterinary referral hospitals between 2003 and 2014 were searched for canine and feline cases diagnosed with triceps tendon disruption, based on orthopaedic examination confirmed during surgery. Long-term follow-up and owner satisfaction were assessed using a questionnaire. There were 13 cases of triceps tendon disruption diagnosed across seven hospitals (nine dogs, four cats). Trauma, history or presence of a wound, surgery in the region of tendon attachment or corticosteroid treatment preceded triceps tendon disruption. Radiographic signs or histopathology suggestive of a chronic tendinopathy was common. All cases underwent surgical repair involving a tendon suture pattern, 12 of which were secured through bone tunnels. Immobilisation was used in all cases in the form of transarticular external skeletal fixation (TAESF) (8/9 dogs) or spica splint (four cats, two dogs; in one dog a TAESF was applied after complications associated with the spica splint). Complications occurred in 11 cases (17 total complications), frequently associated with the immobilisation method. One case had traumatic tendon rerupture two years following surgery. A wound at presentation was associated with the development of multiple complications. Nine cases had long-term follow-up; five achieved normal function, four achieved acceptable function. Despite the complications, overall return to subjective normal or acceptable function, as assessed by the owners, was achieved in the majority of cases.

Evaluation of variables influencing success and complication rates in canine total hip replacement: results from the British Veterinary Orthopaedic Association Canine Hip Registry (collation of data: 2010-2012).

The objective of this study was to assess the variables associated with complications of total hip replacement (THR) and report owner-assessed outcomes. Entries into the British Veterinary Orthopaedic Association-Canine Hip Registry (BVOA-CHR) between September 2011 and December 2012 were reviewed separately and in conjunction with previous data (January 2010-August 2011). An outcomes assessment questionnaire was used to collect data from owners. Incidences of surgeon-reported and owner-reported complications were 8.2 per cent and 4.3 per cent, respectively. THR using the BioMedtrix BFX cup/stem prosthesis had a greater incidence of complications compared with THR using the BioMedtrix CFX cup/stem prosthesis (P=0.002); complications were 4.48 times more likely when using the BioMedtrix BFX cup/stem prosthesis versus the BioMedtrix CFX cup/stem prosthesis. THR using the BioMedtrix BFX cup/stem prosthesis had a higher incidence of complications compared with THR using a hybrid prosthesis (BioMedtrix BFX cup/CFX stem, BioMedtrix CFX cup/BFX stem) (P=0.046); complications were 2.85 times more likely when using the BioMedtrix BFX cup/stem prosthesis versus a hybrid prosthesis. In 95 per cent of cases, owner satisfaction with the outcome of THR was 'very good' or 'good'. Complication rates from the BVOA-CHR are similar to previous studies. The data suggest that prosthesis type is associated with complication rate, with BioMedtrix BFX (circa 2012) having a high short-term complication rate.

Combined physeal fractures of the distal radius and ulna: complications associated with K-wire fixation and long-term prognosis in six cats.

Objectives The objective was to describe the complications and long-term outcome associated with Kirschner (K)-wire fixation of combined distal radial and ulnar physeal fractures in six cats. Methods Medical records (2002-2014) of six referral institutions were searched for cats with combined distal radial and ulnar physeal fractures. Cases with complete clinical files, radiographs and surgical records were retrospectively reviewed. Long-term outcome was assessed via telephone interviews using an owner questionnaire. Results Complete files were available for 6/9 identified cases (cases 1-6). All fractures were classified as Salter-Harris type I or II. Five cases underwent open reduction and internal fixation via cross-pinning of the distal radius and intramedullary pinning of the ulna (cases 1-3); fixation of the distal radial and ulnar physes with one K-wire each (case 4); and K-wire fixation of the radial physis in combination with two transulnoradial K-wires (case 5). One case underwent closed reduction and percutaneous cross-pinning of the distal radius under fluoroscopic guidance (case 6). The complications encountered were: reduced radiocarpal range of motion (ROM) (cases 1, 3, 4, 5); implant loosening/migration (cases 1, 2, 5); and radioulnar synostosis (case 4). None of the cats developed angular limb deformity. Long-term outcome (12 months to 7 years after surgery) was graded as 'excellent' by the owners in all cases. Conclusions and relevance Prognosis is favourable for feline combined distal radial and ulnar physeal fractures following K-wire fixation in cats over 7 months of age. Implant removal after bony union is recommended to minimise reduction in ROM and to prevent implant loosening/migration.

Colored Indicator Undergloves Increase the Detection of Glove Perforations by Surgeons During Small Animal Orthopedic Surgery: A Randomized Controlled Trial.

OBJECTIVE: To determine whether use of colored indicator gloves affects perforation detection rate and to identify risk factors for glove perforation during veterinary orthopedic surgery. STUDY DESIGN: Prospective randomized controlled trial. SAMPLE POPULATION: 574 double pairs of gloves worn during 300 orthopedic surgical procedures (2,296 gloves). METHODS: Primary and assistant surgeons double-gloved for all orthopedic surgical procedures. Type of inner glove (standard or colored indicator) was randomized for the first 360 double pairs of gloves worn by surgeons during 180 procedures. Perforations detected by surgeons were recorded and gloves changed if requested. For a further 120 procedures, indicator gloves were used exclusively. All gloves were leak-tested after surgery to identify perforations. Association between potential risk factors and perforation was explored using multivariate logistical regression analysis. RESULTS: Glove perforations occurred during 43% of surgeries with a mean of 2.3 holes/surgery. Inner gloves were intact in 63% of glove pairs where an outer perforation occurred. Intraoperative perforation detection was improved when colored indicator gloves were worn (83% sensitivity) vs. standard gloves (34% sensitivity; P<.001). Independent risk factors for perforation were placement of plates and/or screws (P=.001; OR=2.4; 95% CI, 1.4-4.0), placement of an external skeletal fixator (P=.002; OR=7.0; 95% CI, 2.1-23.8), use of orthopedic wire (P=.011; OR=2.4; 95% CI, 1.2-4.7), and primary surgeon being board-certified (P=.016; OR=1.9; 95% CI, 1.1-3.1). CONCLUSION: Increased surgeon recognition of glove perforations through use of colored indicator gloves enables prompt change of gloves if perforation occurs and may reduce potential contamination of the surgical site.

Complications associated with corrective surgery for patellar luxation in 85 feline surgical cases.

The objective was to review surgical techniques and postoperative complications of surgical correction for patellar luxation (PL) in cats. A retrospective study evaluating 85 surgeries in 71 cats was performed. The records from four referral centres were searched for cats with surgical management of PL. Signalment, history, PL grade and direction, corrective surgical techniques and outcome were retrieved. Binary logistic regression analysis was used to interrogate relationships between case features, surgical correction methods and outcomes. The outcomes were classified as minor and major complications (requiring revision surgery), including continued PL (reluxation). Postoperative complications occurred in 26% of cases; 20% had major complications, including 5% patellar reluxation, and 6% had minor complications. Cats with previous ipsilateral femoral fracture were significantly more likely to suffer complications, including minor (P = 0.02, odds ratio = 12.67), major (P = 0.03, OR = 7.2) and patellar reluxation (P = 0.01, OR = 19.25). Minor complications were significantly more likely with grade 4 PL (P = 0.03, OR = 8.5). Major complications were significantly more likely with tibial tuberosity transposition (TTT; P = 0.03, OR = 5.57). Patellar reluxation was significantly more likely if stifle surgery had been performed previously (P = 0.05, OR = 8.00). The presence of bilateral PL, hip dysplasia, grade 1, 2 or 3 PL, corrective surgery using an anti-rotational suture or femoral sulcoplasty did not influence complications. Complications were more likely for grade 4 PL, previous ipsilateral femoral fracture, if TTT was performed and for cases with previous stifle surgery. This information allows consideration of risks and complicating factors.

Patellar ligament rupture in the cat: repair methods and patient outcomes in seven cases.

The medical records of cats receiving surgical treatment for unilateral patellar ligament rupture between 1999 and 2012 at 12 referral centres in the UK and Ireland were reviewed. Seven cases were identified: six were caused by trauma and one was iatrogenic, occurring as a complication following surgical stabilisation of a tibial fracture. All cases were treated by sutured anastomosis of the ruptured ligament, with six of the repairs protected by a circumpatellar and/or transpatellar loop of suture. The stifle was immobilised by transarticular external skeletal fixation in three cases. No cases required revision surgery. No complications were reported. Final evaluation, performed at a median time of 31 days, determined five patients to have returned to acceptable or good limb function; two cases were lost to follow-up. The data suggest that, in cats, the current surgical techniques extrapolated from their canine counterparts for repair of a completely or partially ruptured patellar ligament are successfully used and result in acceptable limb function.

Quasi-isometric points for the technique of lateral suture placement in the feline stifle joint.

OBJECTIVE: To evaluate the quasi-isometric points (nearest isometric points) between the distal aspect of the femur and fabella and the proximal aspect of the tibia for placement of a lateral suture in cats. STUDY DESIGN: Radiographic study. ANIMALS: Cadaveric cat stifles (n = 7 cats; 14 stifles). METHODS: Specimens were secured in a mounting frame to maintain rigid fixation of the femur and allow free range of motion of the stifle joint and proximal tibia. Two anatomic landmarks were identified: the center of the lateral fabella (Ff) and a point 4 mm proximal to the insertion of the patellar tendon adjacent to the tibial cortex (Tt). Radiopaque spheres were placed at predefined landmarks in the femur (caudal aspect of the lateral femoral condyle distal [F1] and proximal [F2] to the lateral fabella) and in the tibia (caudal to the proximal aspect of the extensor groove [T1]; cranial to the proximal aspect of the extensor groove [T2]; 2 mm proximal and caudal to the insertion of the patellar tibial tendon [T3] and 3 mm caudal to the insertion of the patellar tibial tendon [T4]. For each stifle, 4 radiographic projections were made: in extension (166°), in flexion (45°), and 2 intermediate stance phases (90°, 130°). ANOVA was used to compare means of the distance between the point pairs and means of the percent change in variation of distance (VOD%) using the 45° measurement as a reference. RESULTS: Mean VOD% nearest to zero, over all the different angles tested, was produced by Ff-Tt, which was statistically significantly different from each of the other point pairs. CONCLUSION: Ff-Tt provides the best quasi-isometric points for placement of lateral sutures in cats, compared with all combinations tested. Further assessments with biomechanical studies are needed to evaluate the reproducibility of these landmarks for stabilization of CCL rupture in cats.

Idiopathic ischemic necrosis of an accessory carpal bone in a dog.

CASE DESCRIPTION: A 6-year-old neutered female mixed-breed dog was evaluated because of a 6-week history of left forelimb lameness that varied in severity. CLINICAL FINDINGS: Radiography revealed expansile and lytic changes of the left accessory carpal bone (ACB). Results of histologic evaluation of ACB core biopsy specimens indicated areas of bone necrosis. The entire left ACB was excised and submitted for histologic evaluation; results confirmed a diagnosis of idiopathic ischemic necrosis. TREATMENT AND OUTCOME: Left pancarpal arthrodesis was performed to treat carpal hyperextension and persistent lameness. The dog had an excellent functional outcome with no other problems related to the carpus until its death 4 years later, further decreasing suspicion that the problem was attributable to an undetected neoplasm or bacterial or fungal osteomyelitis. CLINICAL RELEVANCE: The radiographic and histologic findings for the dog of this report were similar to previously reported findings for dogs with ischemic femoral head necrosis and humans with ischemic carpal (pisiform or lunate bone) necrosis. The etiology of the ischemic ACB necrosis in this dog was not determined. To the authors' knowledge, this is the first report of a dog with idiopathic ischemic ACB necrosis. Idiopathic ischemic necrosis should be included as a differential diagnosis for dogs with lameness and destructive and expansile ACB radiographic lesions. An excellent functional outcome may be attained by means of ACB excision and pancarpal arthrodesis.