Shoulder lameness in horses: an analysis of 58 suspected cases

The results of a detailed investigation of 58 horses with suspected shoulder lameness are described. Lameness was found to originate distal to the shoulder region in 22 horses. No diagnosis was reached in five horses. Genuine shoulder problems occurred in 29 horses. The clinical signs of shoulder lameness are described and contrasted with lower limb lameness. The limitations of currently available diagnostic techniques are discussed. Problems identified in the shoulder region included osteochondritis dissecans, subchondral bone cysts, arthrosis, fracture, luxation, septic arthritis and soft tissue damage. Some of the differences between osteochondritis dissecans and subchondral bone cysts are described and it is suggested that these are two separate conditions.     

Fractures of the accessory carpal bone in the horse

The clinical signs and radiographic appearance of 19 cases of fracture of the accessory carpal bone of horses are described. In 17 cases the fractures were in the frontal plane and occurred palmar to the groove on the lateral aspect of the bone. In six cases radiographs taken six months to three years after the fracture occurred showed no evidence of bony union; nevertheless, these and five other horses for which follow-up information was available for up to seven years all became sound, and seven of them returned to competitive activity.     

DISTAL PHALANX FRACTURES IN HORSES

The case records of 274 horses with fractures of the distal phalanx were reviewed. Fifty-two horses had bilateral forelimb fractures, for a total of 326 distal phalanx fractures. The fractures were classified into one of five previously described types, based on the radiographic anatomic configuration of the fracture. Solar margin fractures, which have been briefly described in other reports and previously classified as type V fractures, were identified in 132 horses. This type of fracture is distinct from other distal phalanx fractures. Due to the high incidence of solar margin fractures, these fractures were classified as a separate type (type VI). Follow-up radiographic examinations to assess fracture healing were available for 36 horses. Twenty-two horses with distal phalanx fractures (three type I, nine type II, two type III, one type IV, one type V, and six type VI) had radiographic evidence of complete bony union of the fracture at a mean of 11 months after injury. Eight horses with complete type II fractures involving the articular surface had bony union of the body and solar margin, but not the subchondral bone at the articular surface, a mean of 11 months after injury. Six horses (four type II and two type IV) had little radiographic evidence of bony healing during the follow-up period. All fractures that eventually healed had evidence of progression toward bony union by 6 months after injury.     

Fracture of the Supraglenoid Tubercle Treatment and Results in Five Horses

Five horses with fractures of the supraglenoid tubercle (tuber scapulae) were presented from 6 weeks to 1 year after injury. Clinical signs included lameness characterized by a shortened cranial phase of the stride and shoulder muscle atrophy. Radiographically, the fractures differed in the degree of cranioventral displacement of the fragment as well as the extent of joint involvement. Three horses were treated by resection of the fractured tubercle, including one using a new grid approach to the area of the fracture. Two of these horses have returned to athletic activity and one was euthanized due to postoperative infection. One horse with minimal displacement and joint involvement was treated with rest and raced successfully. One horse seen with a fracture of 1 year duration also was treated with rest and was a pasture sound broodmare.     

Fractures of the rostral portion of the mandible and maxilla in horses: 89 cases (1979-1997).

OBJECTIVE: To compare fracture locations, repair methods, complications, and outcomes of horses with fractures of the rostral portions of the mandible and maxilla. DESIGN: Retrospective study. ANIMALS: 89 horses with fractures of the rostral portions of the mandible and maxilla. PROCEDURE: Medical records and radiographs were reviewed. Fractures were categorized by fracture location and stability. Postoperative complications and long-term outcome were determined by clinical examination and telephone interviews with horse owners. RESULTS: 4 fracture types were recognized. Fractures involving just the alveolar plate (33%) and those involving the alveolar plate and the body of the bone (32%) were most common and were often repaired by interdental wiring. Unilateral fractures of the mandible (11%) were managed without surgery if stable. Unstable fractures were repaired with wires, a U-shaped bar (U-bar), or a bone plate. Bilateral fractures (24%) were often repaired with orthopedic wires in foals or with a U-bar, acrylic splint, wires, or bone plate in adult horses. In 2 horses, bilateral fractures were managed conservatively. Short-term complications developed in 24 of 89 (27%) horses. Soft tissue infections and wire loosening or failure were the most common short-term and long-term complications. Wire replacement was not required in any horses after release from hospital. Persistent draining tracts were most often associated with bone sequestration. Long-term functional and cosmetic outcomes were favorable for all fracture types and repair methods. CLINICAL IMPLICATIONS: Although complications in horses with fractures of the mandible and maxilla are common, long-term prognoses for functional and cosmetic outcome are favorable.     

Autologous Platelet Concentrates as a Treatment for Shoulder Injury in a Horse

Shoulder injury is an uncommon cause of lameness in horses. Trauma to the shoulder region may produce bone and soft-tissue damage. The present study describes the case of a severe left shoulder injury caused by blunt trauma in a 6-year-old gelding. Clinical and ultrasonographic examination revealed fracture of the supraglenoid tuberosity of the scapula and of the lesser tubercle of the humerus with fiber disruption and hematoma of the biceps brachii, bicipital bursitis, and suprascapular nerve damage. The gelding was successfully treated with three intralesional injections of autologous platelet concentrates administered at 2-week intervals. Although all these combined injuries took a minimum of 18 to 24 months for full recovery, the gelding reached full recuperation of the affected limb in 10 months. These results suggest that injections of autologous platelet concentrate could provide a therapeutic benefit in the treatment of shoulder bone fractures and soft-tissue injuries in horses.     

Distal splint bone fractures in the horse: an experimental and clinical study

An experimental and clinical study to investigate the aetiology of distal splint bone fractures is described. In vitro, extension of the fetlock did not appear to alter the position of the distal ends of the splint bones, although tension in the interosseous tendons increased. Flexion of the fetlock resulted in slight outward displacement of the distal ends of the splint bones. It is suggested that concurrent desmitis of the suspensory ligament can cause movement of the ends of the splint bones thus predisposing to a fatigue fracture. In a clinical study of 87 horses, 114 splint bone fractures were identified. In at least 70 per cent of horses, suspensory desmitis was present. Follow up information was available in 24 horses in which more than 80 per cent of the fractures healed spontaneously. Non-union fractures were not painful and did not cause lameness.     

RADIOGRAPHIC APPEARANCE OF EQUINE LUMBOSACRAL AND PELVIC ABNORMALITIES BY LINEAR TOMOGRAPHY

Radiologic findings are described in 20 horses with clinical signs of a caudal lumbar or hindlimb problem; the horses were subjected to linear tomography of the lumbosacral and pelvic regions. The cases could be divided into four groups: sacroiliac arthrosis (6 horses), lumbosacral abnormalities (3 horses), pelvic or lumbar fracture (6 horses), and no radiographic abnormalities (5 horses). Five of the six horses with sacroiliac arthrosis had spur formation, with localized arthrosis at the caudal aspect of the sacral wing and its articulation with the auricular surface of the ilium. In one horse these lesions were confirmed at postmortem examination. The sixth horse, a Standardbred trotter, had more even and widespread arthrosis of the sacroiliac joint. The three lumbosacral abnormalities were present in two horses with fusion of the L₅-L₆ articulation and one horse with a wider than normal sacrolumbar articulation. Linear tomography also proved to be of diagnostic and prognostic value in the evaluation of lumbar and pelvic fractures. Finally, tomography could be used to eliminate the presence of sacroiliac or lumbosacral damage in some horses that presented with clinical signs suggestive of disease of the lumbosacral or sacroiliac region.     

Dorsal Frontal Fractures of the First Phalanx in the Horse

Dorsal frontal fractures of the first phalanx in nine horses are described. All fractures were in hindlimbs, and two horses were affected bilaterally. Of the eleven fractures, seven were incomplete and nondisplaced, one was complete and nondisplaced, and three were complete and displaced. Two horses with complete displaced fractures had their fractures repaired with lag screw fixation combined with open reduction, and the other seven horses were treated nonsurgically.
All horses were sound on the injured limb within 3 to 6 months of the injury. Lag screw fixation was recommended for horses with complete, displaced dorsal frontal fractures in order to reduce the articular defect and help prevent secondary joint changes. Nonsurgical therapy in the form of stall rest with a heavy support wrap resulted in bony healing of the fracture in 4 to 6 months.
Follow-up was obtained on all nine horses: two were retired for breeding; five performed equal to or better than their previous level of racing performance; one was performing successfully as a combined training horse; and one returned to a lower level of performance due to an unrelated forelimb lameness.     

Palmar/Plantar Process Fractures of the Proximal Phalanx In 15 Horses

Fifteen fractures of the palmar or plantar process of the proximal phalanx in 15 horses are described. Ten were articular and five were nonarticular. Two modes of therapy were used depending on the location of the fracture. Nonarticular fractures were treated with stall rest or reduction in exercise, and articular fractures were treated with either surgical removal or internal fixation of the fragment. All horses that were operated on were sound within 6 months after surgery. Follow-up information was obtained on all horses through client questionnaire and race records in the racing breeds (Standardbred and Thoroughbred) and client questionnaire alone is the nonracing breeds (Quarterhorse and Arabian). Fourteen horses returned to an equal or better level of performance than before injury; one horse returned to a lower level of performance.     

Factors associated with racing performance of Thoroughbreds undergoing lag screw repair of condylar fractures of the third metacarpal or metatarsal bone

OBJECTIVE: To evaluate effects of sex, fracture configuration, affected limb, and screw placement on outcome of Thoroughbreds with condylar fractures involving the third metacarpal or metatarsal bone. DESIGN: Cohort study. Animals-56 horses. PROCEDURE: Age, sex, affected limb, fracture configuration, fracture length, fracture fragment width, and distance of the most distal screw from the articular surface were analyzed in logistic regression models. RESULTS: Females were more likely to have displaced fractures and race in fewer races after surgery than males. Sex and fracture configuration were associated with number of postoperative races. Among horses that returned to racing, those with thicker fracture fragments were 11 times as likely as horses with thinner fracture fragments to win a race after surgery. Horses with longer fractures and older horses had fewer postoperative races. Horses in which the most distal screw had been placed further from the joint surface had more races. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that female horses with displaced condylar fractures and male horses with nondisplaced condylar fractures are more likely to be referred for treatment. The effect of sex on outcome for these horses cannot be clearly separated from the effect of fracture configuration. When adjusted for fracture configuration, males were 6 times as likely as females to race after surgery. When adjusted for sex, horses with nondisplaced fractures were 17 times as likely as horses with displaced fractures to race after surgery. Results suggest that the most distal screw should be placed above the epicondylar fossa.     

Condylar fracture of the cannon bone with axial sesamoid fracture in three horses

The case histories of three young thoroughbred racehorses with displaced lateral condylar fractures combined with an axial fracture of the lateral sesamoid bone are described. In two cases the condylar fracture was repaired surgically but both horses developed severe degenerative joint disease and remained lame. The third horse was destroyed humanely. It is important that axial fractures of the sesamoid bone are recognised so that a poorer prognosis can be given for treatment of condylar fractures in racing thoroughbreds.     

Problems associated with the interpretation of the results of regional and intra-articular anaesthesia in the horse

The difficulties associated with the interpretation of the results of regional and intra-articular anaesthesia are discussed with reference to eight lame horses. The clinical and radiographic features of each horse are described, together with the results of anaesthesia. One horse had clinical and radiographic signs consistent with navicular disease but it was not possible to relieve the lameness. Two horses had fractures of bones within the foot but lameness was not improved by palmar (abaxial sesamoid) nerve blocks. One horse had more than one cause of lameness. Four horses had joint pathology but none responded to intra-articular anaesthesia.     

Short incomplete sagittal fractures of the proximal phalanx in ten horses not used for racing

Objective— To describe short incomplete sagittal fractures of the proximal phalanx (type Ia P1 fractures) in horses not used for racing and report outcome.
Study Design— Retrospective study.
Animals— Horses (n=10) with type Ia P1 fractures.
Methods— Retrieved data of horses with type Ia P1 fractures were signalment, history and results of orthopedic examination. Radiographs were re-evaluated for position and length of the fracture line, presence of osteoarthritis or subchondral cystic lesions (SCL), periosteal new bone formation and subchondral sclerosis. Conservative treatment (n=4) included box confinement for 2 months followed by 1 month of hand walking. Surgical therapy (n=6) consisted of internal fixation by screws inserted in lag fashion in 5 horses. Concurrent SCL were debrided by curettage via a transcortical drilling approach. In 1 horse, only SCL curettage but not internal fixation was performed. Outcome was assessed on a clinical and radiographic follow-up examination in all horses.
Results— Mean follow-up time was 27 months (median, 13.5 months; range, 9 months to 9 years). All horses treated with internal fixation were sound at follow-up and had radiographic fracture healing. Of the 4 horses managed conservatively, 3 remained lame and only 1 horse had radiographic evidence of fracture healing. Catastrophic fracture propagation occurred in 2 horses not treated by internal fixation, 20 and 30 months after diagnosis, respectively.
Conclusions— Horses with a type Ia P1 fracture treated surgically had a better outcome than those managed conservatively and lack of fracture healing seemingly increases the risk of later catastrophic fracture.
Clinical Relevance— Surgical repair of type Ia P1 fractures should be considered to optimize healing and return to athletic use.     

Evaluation of transfixation casting for treatment of third metacarpal, third metatarsal, and phalangeal fractures in horses: 37 cases (1994-2004)

OBJECTIVE: To evaluate clinical findings, complications, and outcome of horses and foals with third metacarpal, third metatarsal, or phalangeal fractures that were treated with transfixation casting. DESIGN: Retrospective case series. Animals-29 adult horses and 8 foals with fractures of the third metacarpal or metatarsal bone or the proximal or middle phalanx. PROCEDURES: Medical records were reviewed, and follow-up information was obtained. Data were analyzed by use of logistic regression models for survival, fracture healing, return to intended use, pin loosening, pin hole lysis, and complications associated with pins. RESULTS: In 27 of 35 (77%) horses, the fracture healed and the horse survived, including 10 of 15 third metacarpal or metatarsal bone fractures, 11 of 12 proximal phalanx fractures, and 6 of 8 middle phalanx fractures. Four adult horses sustained a fracture through a pin hole. One horse sustained a pathologic unicortical fracture secondary to a pin hole infec-tion. Increasing body weight, fracture involving 2 joints, nondiaphyseal fracture location, and increasing duration until radiographic union were associated with horses not returning to their intended use. After adjusting for body weight, pin loosening was associated with di-aphyseal pin location, pin hole lysis was associated with number of days with a transfixation cast, and pin complications were associated with hand insertion of pins. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that transfixation casting can be successful in managing fractures distal to the carpus or tarsus in horses. This technique is most suitable for comminuted fractures of the proximal phalanx but can be used for third metacarpal, third metatarsal, or middle phalanx fractures, with or without internal fixation.     

Incomplete Oblique Sagittal Fractures of the Dorsal Cortex of the Third Metacarpal Bone in Six Horses

Objective —To describe incomplete oblique sagittal dorsal cortical fractures of the equine third metacarpal bone, their surgical repair, and subsequent performance of the horses.
Study Design —Retrospective examination of medical records and racing performance.
Animal Population —Six Thoroughbred race horses, 2 to 4 years of age.
Methods —Radiographic confirmation of all fractures preceded general anesthesia and surgical correction. Three fractures were treated by intracortical compression using screws placed in lag fashion, and five fractures were treated by osteostixis. Race records were reviewed for each horse to determine performance after surgery.
Results —Fractures were best observed on palmarodorsal radiographic projections. Three horses treated by intracortical compression returned to racing, but fracture recurred in one horse and was treated by osteostixis. This horse and the other three horses treated by osteostixis raced after surgery.
Conclusions —Horses with incomplete oblique sagittal fractures of the dorsal cortex of the third metacarpal bone can race after surgical management of the fracture by screws placed in lag fashion or osteostixis. The authors' preferred surgical procedure for managing this fracture is osteostixis.
Clinical Relevance —Palmarodorsal radiographic projections of the third metacarpal bone are recommended in young Thoroughbred race horses suspected of having dorsal metacarpal stress fractures.     

Management of comminuted fractures of the proximal phalanx in horses: 64 cases (1983-2001)

OBJECTIVE: To report the outcome of surgical treatment of comminuted fractures of the proximal phalanx in horses. DESIGN: Retrospective study. ANIMALS: 64 horses. PROCEDURE: Medical records and radiographs were reviewed to obtain information regarding signalment, fracture classification, and treatment. Follow-up information was obtained by telephone conversation or evaluation of production records. RESULTS: Thirty-eight horses had moderately comminuted fractures of the proximal phalanx. Two horses were euthanatized immediately. Fractures of the proximal phalanx in 36 horses were repaired with open reduction and internal fixation with a successful outcome in 33 (92%) horses. Reconstruction of the fracture was performed in most horses by use of a long curved incision, transection of the collateral ligament of the metacarpophalangeal or metatarsophalangeal joint, and open exposure of the proximal articular surface of the proximal phalanx. Twenty-six horses had severely comminuted fractures of the proximal phalanx. Six horses were euthanatized immediately. One horse was euthanatized after 9 days of treatment with a cast alone. Severely comminuted fractures of the proximal phalanx in 13 horses were treated with an external skeletal fixation device, and fractures healed in 8 of those horses. Six horses with severely comminuted fractures of the proximal phalanx were treated with transfixation pins incorporated into a fiberglass cast, and fractures healed in 4 horses. CONCLUSIONS AND CLINICAL RELEVANCE: Moderately comminuted fractures of the proximal phalanx can be successfully repaired; however, fractures that are too severe to permit accurate reconstruction of the fragments remain difficult to treat and horses have only a fair prognosis for survival.     

Technetium-99m-HDP uptake characteristics in equine fractures: a retrospective study

Bone scintigraphy is a very sensitive diagnostic tool to detect elevated bone metabolism. In cases of fractures and fissure fractures, the radiopharmaceutical uptake in the bone is said to be increased within a few hours after the injury. In this retrospective study, the scintigraphic uptake characteristics at the fracture site of 36 horses with radiographically confirmed fractures or fissure fractures were evaluated. Uptake ratios between the fracture region and adjacent normal bone or soft tissue activity respectively were calculated and compared to different anamnestic and radiographic data. The overall sensitivity of bone scintigraphy was 94.4% (34 positive cases out of 36). In the 36 horses, no correlation between the age of the fracture and the radiopharmaceutical uptake was found. However, there seems to be a lack of sensitivity in early detection of equine pelvic fractures when a standing bone scintigraphy examination protocol is used.