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Background: To investigate the incidence of implant-related complications when humeral unicondylar fractures in immature dogs are stabilised with a transcondylar bone screw and epicondylar Kirschner wire (K-wire)/pin., Methods: Records of cases treated by the author in this clinic over a 10-year period were screened for those involving humeral condylar fractures. These were then reduced to include those patients who were less than 7 months of age with unicondylar fractures and follow-up radiographs., Results: Thirty fractures in 29 dogs met the inclusion criteria. All of these had been stabilised with a transcondylar bone screw and epicondylar K-wire. Fracture healing was documented in all dogs. Surgical site infection was not recorded. Implant-related major complications were reported in four (13%) dogs and successfully treated by either implant removal or replacement. Short-term outcome was judged as excellent in 23 out of 30 and good in seven out of 30 of these fractures., Conclusion: The use of a transcondylar bone screw in combination with an epicondylar K-wire is an appropriate fixation method for humeral unicondylar fractures seen in puppies less than 7 months of age., (© 2022 British Veterinary Association.)

Background: A triangular screw configuration has been suggested as preferable for repair of sagittal fractures of the proximal phalanx., Objective: To assess the outcome of a triangular screw construct for repair of incomplete and complete minimally displaced proximal phalanx fractures under standing sedation in a population of Thoroughbred racehorses, compared with a cohort repaired using a linear screw configuration., Study Design: Retrospective cohort study., Methods: Medical records and radiographs were accessed to garner clinical data. Date of return to racing was determined from www.racingpost.com. Survival data were compared using log-rank test., Results: Sixty-two horses with one horse having two separate fractures. Fifty-four fractures were repaired using triangular screw configuration, 10 with a linear screw configuration. 81% (43/53) of horses with triangular repair returned to racing at a median of 289 days (161-482 days), 70% (7/10) horses with linear screws returned to racing at a median of 351 days (230-815 days)., Main Limitations: A limited number of horses underwent conventional (linear) screw placement., Conclusion: A triangular screw configuration placed in the standing sedated horse is an effective way to repair incomplete and complete minimally displaced proximal phalanx fractures. The rate of return to racing was excellent with a low rate of complications., (© 2020 EVJ Ltd.)

This study evaluated the feasibility, complications and long-term outcomes of using a cannulated drill system combined with intraoperative imaging to place a transcondylar screw for the management of canine humeral intracondylar fissure. Thirteen dogs were enrolled, with one dog undergoing staged bilateral surgery. No intraoperative complications occurred. Five minor (36%) and three major (21%) postoperative complications occurred, giving an overall complication rate of 57%. None of the screws placed penetrated the articular surface. The mean duration of surgery was 28 min (SD ±3.5) for dogs that developed a major complication versus 46 min (SD ±18.1) for those that did not (p=0.015). The duration of preoperative lameness was significantly shorter for cases which suffered a major complication (2 days; SD ±2.8) than those that did not (34 days; SD ±31.7, p=0.008). None of the variables assessed were significantly associated with minor complications. Median time from surgery to last follow-up was 5.8 years (range 3.5-8.5 years). Median Liverpool Osteoarthritis in Dogs questionnaire score at the final point of follow-up was 16 (range 7-27). A significant number of patients were found to require analgesia at long-term follow-up., Competing Interests: Competing interests: None declared., (© British Veterinary Association 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: Despite the recommendation of plate fixation for propagating condylar fractures of the third metacarpal (McIII) or third metatarsal bone (MtIII), lag screw fixation can be a viable surgical option., Objectives: To evaluate short-term outcome and long-term racing performance of horses that underwent lag screw fixation of long condylar fractures of the McIII/MtIII., Study Design: Retrospective case series., Methods: Medical records, post-surgical racing performance and outcome of 26 horses with propagating fractures of the medial and/or lateral condyle of McIII/MtIII were reviewed. Medical information included were age, breed, sex, physical examination at admission, circumstances of fracture, radiographic evaluation, anaesthesia and recovery records, surgical and post-operative management, as well as complications. Outcome included racing data and information from telephone interviews., Results: Twenty-six horses (9 Standardbreds and 17 Thoroughbreds) were admitted with a long condylar fracture of the McIII/MtIII. Fore- and hindlimbs were equally represented with the left hindlimb being more frequently involved. Most of the fractures had a spiralling component (76%) and four (15%) were comminuted. Fifteen (58%) horses raced post-surgery including nine Standardbreds (100%) and six Thoroughbreds (35%). Twelve of them were placed in at least one race and 11 won at least once. One horse sustained a severe complication in recovery. No significant difference was observed in the racing performances before and after surgery., Main Limitations: Follow-up method and duration were not standardised and there is a low number of cases with six surgeons., Conclusions: Long condylar fractures can be repaired using lag fashion technique combined with a half-limb or full-limb tight cast for recovery as a good surgical alternative. Similar results to plate fixation can be expected, with a return to racing of more than 50%, and the prognosis being even better for pacers., (© 2018 EVJ Ltd.)

Reasons for Performing the Study: A technique for minimally invasive repair of slab fractures of the third tarsal bone has not previously been reported. Results of third tarsal bone slab fracture repair in Thoroughbred racehorses are lacking., Objectives: To report the outcomes of repair of uniplanar frontal slab factures of the third tarsal bone using a single 3.5 mm cortex screw in lag fashion., Study Design: Retrospective case series., Methods: Case records of horses that had undergone this procedure were reviewed., Results: Seventeen horses underwent surgery. Eighteen percent of cases had wedge shaped third tarsal bones. A point midway between the long and lateral digital extensor tendons and centrodistal and tarsometatarsal joints created a suitable entry site for implants. The fracture location, configuration and curvature of the third tarsal bone and associated joints requires a dorsolateral proximal-plantaromedial distal trajectory for the screw, which was determined by preplaced needles. There were no complications and fractures healed in all cases at 4-6 months post surgery. Seventy-nine percent of horses returned to racing and, at the time of reporting, 3 are in post operative rehabilitation programmes., Conclusion: The technique reported provides a safe, appropriate and repeatable means of repairing slab fractures of the third tarsal bone. Surgical repair is a viable alternative to conservative management., (© 2016 EVJ Ltd.)

Reasons for Performing Study: Standing fracture repair in the horse is a recently described surgical procedure and currently there are few follow-up data. This case series contains 2 novel aspects in the standing horse: repair of incomplete sagittal fractures of the proximal phalanx and medial condylar repair from a lateral aspect., Objectives: To describe outcome in a case series of horses that had lower limb fractures repaired under standing sedation at Rossdales Equine Hospital., Method: Case records for all horses that had a fracture surgically repaired, by one surgeon at Rossdales Equine Hospital, under standing sedation and local anaesthesia up until June 2011, were retrieved. Hospital records, owner/trainer telephone questionnaire and the Racing Post website were used to evaluate follow-up., Results: Thirty-four horses satisfied the inclusion criteria. Fracture sites included the proximal phalanx (incomplete sagittal fracture, n = 14); the third metacarpal bone (lateral condyle, n = 12, and medial condyle, n = 7); and the third metatarsal bone (lateral condyle, n = 1). One horse required euthanasia due to caecal rupture 10 days post operatively. Twenty horses (66.7% of those with available follow-up) have returned to racing. Where available, mean time from operation to return to racing was 226 days (range 143-433 days)., Conclusions: Standing fracture repair produced similar results to fracture repair under general anaesthesia in terms of both the number of horses that returned to racing and the time between surgery and race., Potential Relevance: Repair of lower limb fracture in the horse under standing sedation is a procedure that has the potential for tangible benefits, including avoidance of the inherent risks of general anaesthesia. The preliminary findings in this series of horses are encouraging and informative when discussing options available prior to fracture repair., (© 2012 EVJ Ltd.)

Reasons for Performing Study: Surgical correction of carpal angular limb deformities by growth retardation is commonly undertaken with a screws and tension band wire loop technique (S&W) or a single transphyseal screw (STS). This study compares complications after S&W and STS bridging in the distal radius of Thoroughbred yearlings., Objective: To compare the prevalence of complications serious enough to require follow-up radiographs following either S&W or STS surgery for growth manipulation in the distal radius of Thoroughbred yearlings., Methods: Medical records and radiographs from Thoroughbred yearlings (age range 261-457 days) treated for carpal angular limb deformities at a single hospital over 2 years were reviewed. Each of the techniques was used exclusively during a single year. The complication threshold criterion for inclusion was the need for nonroutine radiographs of the operated site anytime after implant insertion or removal., Results: Of 568 horses, 253 received S&W and 315 received STS. Horses were of similar age at the time of surgery for STS and S&W. Single transphyseal screws were left in place for a significantly shorter amount of time (16 days). Sex, the limb(s) treated and medial vs. lateral placement were not significantly different between techniques. Complications included physitis post implant removal, metaphyseal collapse post implant removal, infection, overcorrection and seroma formation severe enough to require radiography. Physitis and metaphyseal collapse occurred significantly more frequently with STS compared with S&W. Infection, overcorrection and seromas were not significantly different between techniques., Conclusion: The STS and S&W techniques are both viable treatment options for correction of carpal angular limb deformities. However, horses treated with the STS technique have a significantly increased risk of developing physitis or metaphyseal collapse., Potential Relevance: Horses treated with STS bridging have a significantly increased risk of developing the post correction complications of moderate to severe physitis and metaphyseal collapse compared with horses treated with S&W bridging., (© 2011 EVJ Ltd.)

Reasons for Performing the Study: Removal of large chip fractures of the carpal bones and the osteochondral deficits that result, have been associated with a worse prognosis than removal of small fragments in similar locations., Hypothesis: Reducing the articular defects by repair of large osteochondral fragments may have advantages over removal., Methods: Horses with osteochondral chip fractures that were of sufficient size and infrastructure to be repaired with small (2.7 mm diameter) AO/ASIF cortex screws were identified and repair effected by arthroscopically guided internal fixation., Results: Thirty-three horses underwent surgery to repair 35 fractures of the dorsodistal radial carpal bone (n = 25), the dorsal margin of the radial facet of the third carpal bone (n = 9) and the intermediate facet of the distal radius (n = 1). There were no surgical complications and fractures healed satisfactorily in 26 of 28 horses and 23 horses returned to racing performance., Conclusion: Arthroscopically guided repair of carpal chip fractures with small diameter cortex screws is technically feasible and experiences with 33 cases suggest that this may have advantages over fragment removal in managing such cases., Potential Relevance: Surgeons treating horses with large chip fractures of the carpal bones should consider arthroscopically guided internal fixation as an alternative to removal., (© 2010 EVJ Ltd.)

Reasons for Performing Study: The effectiveness and best method to manage dorsal cortical stress fractures is not clear. This study was performed to evaluate the success of lag screw fixation of such fractures in a population of Thoroughbred racehorses., Hypothesis: Lag screw fixation of dorsal cortical stress fractures is an effective surgical procedure allowing racehorses to return to their preoperative level of performance., Methods: The records of 116 racehorses (103 Thoroughbreds) admitted to Equine Medical Centre, California between 1986 and 2008 were assessed. Information obtained from medical records included subject details, limb(s) affected, fracture configuration, length of screw used in repair and presence of concurrent surgical procedures performed. Racing performance was evaluated relative to these factors using Fisher's exact test and nonparametric methods with a level of significance of P<0.05., Results: Of 92 Thoroughbred horses, 83% raced preoperatively and 83% raced post operatively, with 63% having ≥5 starts. There was no statistically significant association between age, gender, limb affected, fracture configuration or presence of concurrent surgery and likelihood of racing post operatively or of having 5 or more starts. The mean earnings per start and the performance index for the 3 races following surgery were lower compared to the 3 races prior to surgery; however, 29 and 45% of horses either improved or did not change their earnings per start and performance index, respectively., Conclusions and Potential Relevance: Data show that lag screw fixation is successful at restoring ability to race in horses suffering from dorsal cortical stress fractures., (© 2010 EVJ Ltd.)

Reasons for Performing Study: Fracture repair and arthrodesis in horses require rigid fixation in order to achieve early post operative comfort. The locking compression plate (LCP) was designed to allow greater stability and less periosteal disruption than conventional plates., Objective: To describe a series of clinical cases in which the LCP was used for fracture stabilisation or arthrodesis., Methods: Medical records, radiographs and follow-up for 31 horses having fracture stabilisation or arthrodesis with the LCP were reviewed. Reasons for treatment included fracture of the olecranon (n = 2), metatarsal III (n = 2), ilial shaft (n = 1), femur (n = 2), radius (n = 2), medial condylar (n = 5) and complex lateral condylar (n = 1); or arthrodesis of the metacarpophalangeal joint (n = 8), proximal interphalangeal joint (n = 8) and carpus (n = 2)., Results: Of the 31 horses, 27 were discharged from the hospital. Complications included incisional infection (32%), implant infection (19%), implant loosening/ breakage (22%), contralateral limb laminitis (16%), colic (3%) and diarrhoea (3%). Follow-up was available on all horses with at least 6 weeks of follow-up ranging up to 25 months. Of the 31 horses, 25 are sound for intended purpose, one is lame and 5 were subjected to euthanasia for complications associated with the original injury., Conclusions: The LCP is an acceptable means of fracture stabilisation and arthrodesis in the horse., Potential Relevance: The LCP should be considered for difficult fracture configurations and arthrodeses, especially when increased stability of the fixation is needed.

Reasons for Performing Study: A method for proximal interphalangeal joint (PIP joint) arthrodesis that provides a stable fixation and minimal duration of cast support is evaluated retrospectively., Objectives: Evaluate the clinical use of a combined plate-screw method for PIP joint arthrodesis in a large number of horses., Methods: The records of 53 horses undergoing PIP joint arthrodesis were reviewed. Arthrodesis was performed with a dorsally placed 3-, 4- or 5-hole narrow dynamic compression plate (DCP) with 2 transarticular cortex screws placed in lag fashion either side of the plate. Subject details, clinical presentation, radiographic findings, surgical technique, post operative treatment and complications were recorded. Long-term follow up (mean 3 years) was obtained for 46 horses., Results: Arthrodesis procedures (n = 58) were performed on 53 horses with a DCP in combination with transarticular cortex screws placed in lag fashion. Conditions treated were osteoarthritis (OA) of the PIP joint, fracture of middle phalanx, PIP joint subluxation, subchondral cystic lesions and degenerative joint disease secondary to sepsis. Time of post operative cast application was 14 days. Overall 40/46 (87%) horses could be used as intended including 20/25 (81%) forelimb and 20/21 (95%) hindlimb arthrodeses. Twenty-three of 27 (85%) horses used for performance had successful outcomes. Complications included implant infection, cast sores and partial implant failure., Conclusions: PIP joint arthrodesis using a DCP and transarticular cortex screws placed in lag fashion provides a stable construct and short casting period with minimal complications. The prognosis for return to performance was excellent for horses treated with hindlimb PIP joint arthrodesis and good for forelimb arthrodesis., Potential Relevance: Use of a combination technique for PIP joint arthrodesis allows a high proportion of horses with pastern joint disease to be returned to their athletic potential.

Reasons for Performing Study: Repair of spiral and long diaphyseal metacarpal and metatarsal fractures under anaesthesia can be problematic and associated with a high incidence of complications, including fracture propagation necessitating euthanasia., Objective: To report on a practical repair technique for which general anaesthesia is not required., Methods: Thirteen racehorses with a spiral/propagating condylar fracture had the fracture repaired using local anaesthesia and sedation, without the need for general anaesthetic., Results: Ten of the horses returned to training and 8 raced again. Two horses were retired directly to stud. One horse had propagation of the fracture 3 days post surgery, and was subjected to euthanasia., Conclusions and Potential Relevance: Results achieved were comparable to those gained using standard repair techniques under general anaesthesia. The described technique removes the need for general anaesthesia for repair of selected condylar fractures.

Reasons for Performing Study: Complications of osteosynthesis including superficial and deep infections continue to affect adversely outcome in equine surgery of the lower limb., Objective: To describe a technique for minimally invasive plate fixation in horses and evaluate clinical results of the technique., Hypothesis: Lower complication rates would occur in horses treated with a minimally invasive approach compared with conventional techniques., Methods: Cases of minimally invasive plate fixation from January 1999 to December 2003 were evaluated. Case records, radiographs and race records for horses that sustained distal third metacarpal/metatarsal (Mc/tIII) condylar fractures were assessed. Follow-up information was obtained and results analysed. In addition, results for horses that received arthrodesis by a conventional, open approach during the same period were evaluated and statistical analysis was performed., Results: Thirty-two cases of minimally invasive plate fixation were identified (22 incomplete distal Mc/tIII condylar fractures with a spiralling or diaphyseal component, 10 metacarpophalangeal arthrodeses and 4 pastern arthrodeses). For both types of arthrodesis, surgery times and infection rates were lower and survival rates higher in the minimally invasive group, but no statistical difference was found. Spiralling condylar fractures were successfully managed, without catastrophic fracture., Conclusions and Potential Relevance: Minimally invasive percutaneous plate osteosynthesis (MIPPO) can be successfully used for select applications in horses, and may reduce morbidity and mortality in equine fracture repair.

Reasons for Performing Study: Fractured ribs are encountered quite frequently in newborn Thoroughbred foals, often with fatal outcome. Surgical repair of fractures therefore requires consideration as a means of reducing mortality., Objectives: To evaluate the repair of rib fractures using internal fixation techniques in foals at 2 different equine hospitals following similar diagnostics and case selection., Methods: The records of 14 foals that underwent internal fixation of fracture ribs were reviewed. Subject details, clinical presentation, diagnosis, surgical technique, post operative care and complications were recorded. Follow-up information was obtained in 7 foals., Results: The fractured ribs were reduced and stabilised using reconstruction plate(s), self-tapping cortical screws and cerclage wire in 12 cases, Steinmann pins and cerclage wires in 1 case and both techniques in 1 case. Not every rib was reduced on each case. Surgical reduction was performed on an average of 2 ribs, range 1-3 ribs in each foal. At the time of writing, 4 foals had been sold, one age 2 years was in training and 2 others died from unrelated causes., Conclusions: Our data support the use of surgical stabilisation utilising reconstruction plates, self-tapping cortical screws and cerclage wire for selected cases of thoracic trauma in neonatal foals. The use of Steinmann pins may be suboptimal due to cyclic failure, implant migration and the potential for iatrogenic internal thoracic trauma., Potential Relevance: Foals with existing extensive internal thoracic trauma resulting from rib fracture(s), or the potential for such trauma, previously considered to have a guarded to poor prognosis for survival, may be successfully managed with internal fixation of selected fracture sites.

Two koi (Cyprinus carpio) from the same pond developed similar lesions of scoliosis. Radiographic examinations showed that their spines had become malaligned as a result of vertebral compression fractures involving T14 to T16. The vertebrae in both fish were stabilised with screws, k-wire and polymethylmethacrylate. They both appeared to improve after surgery, but they began to decline and died within three months. A postmortem examination revealed multi-organ inflammation that was not associated with the surgical implants.

The purpose of this study was to evaluate a new method of internal fixation technique for pastern arthrodesis. Pastern arthrodeses are performed commonly in horses with chronic osteoarthritis of the pastern joint or, in cases of acute traumatic injury to the pastern, in which the weightbearing bony column must be restored. Chronic osteoarthritis of the pastern is a frequent cause of lameness in the equine athlete and is evidenced by chronic lameness localised to the pastern joint, and supported radiographically by periosteal proliferation and loss of joint space. Nonsurgical and surgical treatments have both been described in the literature. Complications following pastern arthrodesis have been reported on several occasions and appear to focus on excessive periarticular exostoses and increased time in a cast due to prolonged time to bony fusion. The hospital records of horses presenting for pastern arthrodesis to the Rood and Riddle Equine Hospital in Lexington, Kentucky, were reviewed and 22 met criteria for inclusion in the study. Horses with chronic osteoarthritis of the proximal interphalangeal joint or horses with an acute traumatic injury to the pastern undergoing pastern arthrodesis with one of the following techniques were included in the study. Horses with severe comminution of the middle phalanx were excluded. Three 5.5 mm cortical bone screws placed in lag fashion alone or in combination with a 4 or 3 hole dynamic compression plate affixed with 4.5 mm cortical bone screws were compared. A lower limb fibreglass cast was applied in all cases. Period in cast, time to return to intended use, complications encountered and outcome were evaluated. Seven of the 8 hindlimbs treated with the combination technique became sound. Three out of 6 of the front limbs treated with the combination technique became sound. Four of the 5 horses with hindlimbs, and one of the 2 with front limbs, treated with screws only returned to their intended use. The type of internal fixation did not appear to influence the overall number of horses returning to the intended level of performance. The period spent in cast and the time to return to soundness were decreased in horses operated on using the combination technique. We concluded that, in the immediate postoperative period, the combination of the parallel screw technique with a dorsally-applied dynamic compression plate provides the most stable and secure fixation, minimising motion, expediting bone remodelling and therefore favouring rapid fusion of that joint.

A dog and a cat suffered talocalcaneal luxation with plantar displacement of the head of the talus. Each case was associated with luxation of the talocentral joint and subluxation of the calcaneoquartal joint. The collateral ligaments were not significantly disrupted and this made it technically difficult to reduce the luxations. However, after open reduction, the luxations were inherently stable and a positional screw provided long-term stability. Both animals returned to their previous level of activity with no detectable signs of lameness.

The purpose of this study was to evaluate screw fixation with cortical drilling as a surgical treatment for dorsal cortical stress fractures of MCIII in the Thoroughbred racehorse. Details of age, sex, limb affected, fracture assessment, and post operative recommendations were obtained from medical records and radiographs. Fracture healing was assessed radiographically at the time of screw removal. Performance evaluation was determined from race records obtained from The Jockey Club Information System, Lexington, Kentucky. Fifty-six Thoroughbred racehorses were treated surgically for stress fracture of MCIII with screw fixation and cortical drilling. Stress fractures occurred primarily in the left front limb of the male 3-year-olds, in the dorsolateral cortex of the middle third of MCIII. Ninety-seven percent of the fractures travelled in a dorsodistal to palmaroproximal direction. Median period to screw removal was 2.0 months. Evaluation at time of screw removal revealed 98% of single stress fractures of the left front limb were healed radiographically. Median period to resume training was 2.75 months (single stress fractures); median period to race was 7.62 months. There was no statistically significant difference in earnings/start before and after surgical intervention. Of the 63 fractures treated, two recurred. There were no catastrophic failures, and no incisional infections.

The surgical techniques employed in the repair of femoral neck fractures in two dogs and a Charolais calf are described. All the fractures were extracapsular; one of the dogs also had a fractured femoral diaphysis. For both dogs, exposure of the femoral neck was made from a dorsal approach after removal of the greater trochanter, while for the calf, a gluteal transection technique was used. All the fractures were successfully fixed using cortical screws, and in the case of the femoral diaphysis, a vitallium plate was used. All the animals were walking with minimal lameness eight weeks after surgery.

Methods of treating fractures of the olecranon in the horse are reviewed. A further 4 cases are recorded in which the fracture was treated by open reduction and fixation with a heavy duty Venable's plate placed on the caudal aspect of the ulna. Three cases had an oblique fracture through the semilunar notch; this was complicated in one by a fracture of the lateral half of the radial head which resulted in subluxation of the radio-humeral joint. The fracture of the radial head was treated by open reduction and fixation with a lag screw. The fourth case had an oblique fracture of the olecranon just proximal to the semilunar notch, complicated by a fracture of the anconeal process which was removed. The fractures healed within 10 weeks and the plates were removed in all 4 cases. During follow-up periods ranging from 10 to 26 months, all 4 animals became sound.

A series of 79 fractures of the pedal bone in various types of horses are reported and the clinical features described. The fractures were of 3 types--intra-articular or extra-articular, involving the wing of the pedal bone, and fractures of the extensor process. Forty-five horses with a fractured wing of the pedal bone were treated conservatively and 11 by immobilisation of the bony fragment with a compression screw. Conservative treatment was usually successful in the extra-articular fractures. Intra-articular fractures treated conservatively in animals under 3 years had a good prognosis. The results were not so satisfactory in older horses and surgical treatment proved to be the method of choice. All, but one, of the 23 fractures of the extensor process were treated conservatively. The prognosis was not always good, as secondary osteoarthritis of the interphalangeal joint sometimes developed.

Five cases of fracture of the third tarsal bone in racehorses are reported. A method of surgical correction employing a cortical bone screw is described in 2 cases. Healing of the fractures was followed radiographically. Surgical repair permitted both horses to return to competition. The 3 cases treated conservatively suffered a prolonged healing time and excessive new bone formation. They were unable to return to training due to persistent lameness.

Six cases of patella fractures are reported. Three horses presented an avulsion fracture of the medial patellar angle. For a precise diagnosis of this fracture a radiographic skyline view was indispensable; lateral views were not diagnostic. One of these horses recovered after three months' rest but radiographically the fracture remained visible. One horse with a comminuted fracture recovered after five months' rest. A case with a contaminated longitudinal patella fracture was destroyed. The sixth horse had a chip fracture of the dorsomedial part of the patella. The outcome of this case is unknown.

Observations on a series of 38 cases (35 Doberman Pinschers and three Great Danes) of the canine wobbler syndrome are described. Radiographic examinations suggested that the primary lesion is an intervertebral instability at C6/7, but with time, secondary changes of the disc degeneration and prolapse and vertebral body malformation causing stenosis of the vertebral canal occur. Cases detected at a young age and showing only the primary lesion were treated successfully, by disc fenestration alone or by disc fenestration and intervertebral screwing. The success rate in older cases with secondary lesions was poor and in this type of case, cord decompression by dorsal laminectomy appears necessary.

The hock of a greyhound containing a titanium alloy central tarsal replacement was examined histologically. The animal had raced competitively 43 times before retirement. The examination showed that the adaptation and encapsulation of the implant by the surrounding bones, together with the excellent purchase of the screw into the fourth tarsal bone, had maintained the implant in excellent position during vigorous load-bearing. There was no histopathological evidence to suggest that the fixation of the implant was failing. The results provide evidence for the value of titanium alloy implants as a central tarsal replacement in greyhounds with type V fractures, and as a feasible alternative to euthanasia.