Application of a Hook Plate for Management of Equine Ulnar Fractures

Closed fractures of the proximal aspect of the ulna were repaired in 10 horses younger than or equal to 6 months of age by application of a hook plate using a tension band principle. Ulnar fractures were classified as type 1A (2 horses), type 1B (4 horses), type 2 (1 horse), type 3 (1 horse), and type 4 (2 horses); all fractures had displacement of a proximal fragment. Complications were implant deformation (4 horses), screw pullout (1 horse), osseous sequestration (1 horse), ulnar fracture through a hole used to apply a tension device (1 horse), and metacarpophalangeal deformity associated with a displaced anconeal fragment (1 horse). Hook deformation was likely associated with failure to insert screws in all of the proximal holes of the plate and also in two horses, possibly with difficult recovery from anesthesia. Seven horses were discharged from the hospital and were being used for athletic activities. Insertion of the hook through the tendon of the triceps muscle and incorporation of the fragment within the hook can be used to effectively reduce and stabilize a fragment that might otherwise not hold screws.     

Arthroscopic surgery for osteochondral fractures of the proximal phalanx of the metacarpophalangeal and metatarsophalangeal (fetlock) joints in horses

Arthroscopic surgery for osteochondral fractures of the proximal phalanx was performed on 74 fetlock joints of 63 horses for a total of 87 fractures during a 2-year period. The medial dorsal proximal aspect of the proximal phalanx of the forelimbs was most commonly involved (59 fractures), followed by the lateral aspect (26 fractures), and 2 fractures occurred in the fetlock joint of the right hindlimb. At surgery, 82 fragments were removed and 5 fragments that had healed or were embedded in the joint capsule were not removed. Of the fragments removed, 15 were fixed firmly to the proximal phalanx, 63 were easily movable by arthroscopic instruments (but had soft tissue attachments to the proximal phalanx), and 4 were floating free within the joint. Arthroscopic surgery allowed excellent visualization and appreciation of the attachments of fragments and their stage of healing. Horses returned to full race training at an average of 11 1/2 weeks (range, 6 to 24 weeks). Thirty eight of 46 horses (82.6%) with adequate postoperative follow-up returned to athletic performance at least equal to that before fetlock injury.     

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.     

Conservative management of 17 horses with nonarticular fractures of the tibial tuberosity

REASONS FOR PERFORMING STUDY: Fractures of the tibial tuberosity (FTT) are caused by direct trauma, and are the second most commonly reported injury in event horses with stifle trauma. Conservative management of horses with FTT has been advocated, but results and prognosis for this method of therapy are unknown. OBJECTIVES: To report and review the findings of a retrospective study of 17 horses admitted to a veterinary teaching hospital from 1986-2001 with nonarticular FTT that received conservative management. METHODS: Subject details, aetiology of the accident, limb affected, degree of lameness at time of admission, size and degree of displacement of the fracture fragment, complications such as comminution of the fracture fragment or damage to soft tissue structures within the affected stifle, and treatment recommendations were obtained from medical records. Owners and trainers were contacted regarding the horse's return to athletic use. The follow-up period consisted of 11-154 months. RESULTS: Two horses were reportedly sound, but unable to return to competition for unrelated reasons. Of the horses that completed the rehabilitation period, 12/15 (80%) returned to athletic use at the same level as before the injury. Three horses were diagnosed with damage to soft tissue supporting structures of the affected stifle and could not return to their former level of competition. CONCLUSIONS: Concurrent soft tissue damage, diagnosed at the time of the initial injury, was statistically significant in precluding horses from returning to athletic careers. All other variables were found to have no effect upon outcome. POTENTIAL CLINICAL RELEVANCE: This retrospective study suggests that the conservative management of nonarticular FTT is a viable treatment modality in managing athletic equine patients presenting with these fractures.     

Noncomminuted fractures of the proximal phalanx in 69 horses

In a retrospective study, we examined the case records for 69 horses with noncomminuted fractures of the proximal phalanx, excluding proximal chip fractures. Forty-nine of the horses sustained the fracture while racing or training for racing. Radiographic examination of all affected limbs was performed, and fractures were classified into 6 noncomminuted types: midsagittal fractures, including short incomplete midsagittal fractures, long incomplete midsagittal (LIMS) fractures, and complete midsagittal (CMS) fractures; dorsal frontal fractures; distal joint fractures; plantar process fractures; physeal fractures; and oblique fractures. Four horses were destroyed before treatment. Sixty-five horses were treated and 63 survived to go home. Long-term follow-up evaluation of the horses that were sent home revealed that 4 were euthanatized after discharge because of persistent lameness of the fractured limb. Of the 59 remaining horses, 34 returned to racing, 7 were used as show or pleasure riding animals, 8 were used for breeding, and 10 were lost to follow-up. More Standardbreds with noncomminuted proximal phalangeal fractures returned to racing than did Thoroughbreds. Of 30 Standardbreds that raced or trained before the fracture, 23 (76.7%) returned to racing--8 to their previous level of performance, 11 to a lower level of performance, and 4 to an unknown level of performance. The Standardbreds that returned to racing were horses with physeal fractures (2/2), LIMS fractures (4/4), CMS fractures (11/16), short incomplete midsagittal fractures (4/7), distal joint fractures (1/2), and plantar process fractures (1/2). Of 21 Thoroughbreds that raced or trained before the injury, 11 (52.4%) returned to racing--7 to their previous level of performance and 4 to a lower level of performance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Arthroscopic removal of fracture fragments involving a portion of the base of the proximal sesamoid bone in horses: 26 cases (1984-1997)

OBJECTIVE: To determine the outcome of horses with basal fractures of the proximal sesamoid bone from which a fracture fragment involving a portion of the base of the bone was removed arthroscopically and to determine whether fragment size was associated with outcome. DESIGN: Retrospective study. ANIMALS: 26 horses. PROCEDURE: Dorsopalmar and axial-abaxial lengths of the fracture fragment were measured on the dorsopalmar and mediolateral radiographic views, respectively, and percentage of the base of the sesamoid bone involved was estimated. Fractures were classified as grade 1 (< or = 25% of the base involved) or grade 2 (> 25% but < 100% of the base involved). Outcome was classified as successful if the horse started at least 2 races or unsuccessful if the horse started only 1 race or failed to return to racing. RESULTS: There were 24 racehorses and 2 nonracehorses. Twelve (50%) of the racehorses returned to racing and started at least 2 races. Eight of 14 horses with grade-1 fractures and 4 of 10 horses with grade-2 fractures had a successful outcome. Ten of 16 horses without associated articular disease had successful outcomes, compared with 2 of 8 horses with associated articular disease. However, fragment size and presence of associated articular disease were not significantly associated with outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Horses with basal fractures of the proximal sesamoid bone from which a fracture fragment involving a portion of the base of the bone is removed arthroscopically have a fair prognosis for return to racing.     

Conservative treatment of intra-articular distal phalanx fractures in horses not used for racing

OBJECTIVE: To determine the success rate and whether specific patient and treatment factors influenced the outcome after conservative treatment with a bar shoe with quarter clips of intra-articular fractures of the distal phalanx in horses not used for racing. DESIGN: Retrospective study. SAMPLE POPULATION: Thirty-two client-owned horses. PROCEDURE: Hospital records of horses that had been treated conservatively for intra-articular fractures of the distal phalanx at Skara Equine Hospital or Halland Animal Hospital in Sweden between 1995 and 2001 were reviewed. Racehorses in active training and horses affected with other musculoskeletal diseases were excluded from the study. Follow-up was performed by questionnaire and telephone inquires to the owners 1 to 7 years after injury. RESULTS: Twenty-two horses (69%) returned to their previous or expected level of use and did not wear their bar shoe when they were put back into training. There was no statistically significant correlation between outcome and patient or treatment variables, or bony union of the fracture. CONCLUSIONS AND CLINICAL RELEVANCE: Conservative treatment of intra-articular fractures of the distal phalanx carries a fair prognosis for return to previous or expected level of use in horses not used for racing. Radiographic evidence of fracture healing and age of the patient do not seem to influence the prognosis. Horses not used for racing do not need to be shod with a bar shoe with quarter clips for the rest of their athletic career.     

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.     

Management of fractures and exostosis of the metacarpals and metatarsals II and IV in 25 horses

Twenty-five cases of fractures of the second and fourth metacarpal and metatarsal (splint) bones were reviewed. Fourteen fractures involved a thoracic limb and 11 involved a pelvic limb. Fractures of the proximal one-third of splint bones are reported in one of two forms: fractures that are closed, or fractures with a permanent or intermittent draining sinus. Thirteen of the fractures presented were closed fractures and the remaining 12 were open. All of the closed fractures were managed by surgical excision of the distal fragment and the exostosis at the fracture site, followed by primary surgical wound closure. Lag screw fixation of the proximal fragment was used in three cases. All of the open fractures were managed surgically by excision of the distal splint fragment and debridement of the contaminated fracture site. Primary wound closure was used in 11 of the 12 cases. All closed fractures healed by primary intention, and 10 of 13 were free from lameness at one year follow-up. The 11 open wounds which were operated and subsequently closed under suture healed by primary intention. The wound left open healed by granulation, scar contraction, and epithelialisation. Eight of these horses were sound one year later. The remainder of the open fractures were lost to follow-up.     

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.     

Risk factors for proximal sesamoid bone fractures associated with exercise history and horseshoe characteristics in Thoroughbred racehorses

OBJECTIVE: To assess individual and combined associations of high-speed exercise and horseshoe characteristics with risk of forelimb proximal sesamoid bone fractures and proximal sesamoid bone midbody fractures in Thoroughbred racehorses. ANIMALS: 269 deceased Thoroughbred racehorses. PROCEDURES: A case-control study design was used to compare 121 horses with a fracture of at least 1 of 4 forelimb proximal sesamoid bones (75 horses had a midbody fracture) and 148 horses without a forelimb proximal sesamoid bone fracture. Univariable and multivariable logistic regression analyses were used to evaluate potential risk factors for association with proximal sesamoid bone fracture. RESULTS: Compared with horses that died without proximal sesamoid bone fractures, horses that died with proximal sesamoid bone fractures were more likely to be sexually intact males, spend more time in active trainingand racing, complete more events, train and race longer since their last layup, have higher exercise intensities during the 12 months prior to death, and have greater cumulative distances for their career. Horses with proximal sesamoid bone midbody fractures were more likely to be sexually intact males, train and race longer since their last layup, and have higher exercise intensities during the 12 months prior to death. CONCLUSIONS AND CLINICAL RELEVANCE: Limitingexercise intensity and the continuous time spent in activity duringa horse's career may decrease the frequency of forelimb proximal sesamoid bone fractures in Thoroughbred horses.     

Surgical Management of Proximal Splint Bone Fractures in the Horse

Fractures of Metacarpal and Metatarsal II and IV (the splint bones) were treated in 283 horses over an 11 year period. In 21 cases the proximal portion of the fractured bone was stabilized with metallic implants. One or more cortical bone screws were used in 11 horses, and bone plates were applied in 11 horses. One horse received both treatments. Complications of screw fixation included bone failure, implant failure, radiographic lucency around the screws, and proliferative new bone at the ostectomy site. Only two of the horses treated with screw fixation returned to their intended use. Complications of plate fixation included partial fixation failure (backing out of screws), wound drainage, and proliferative bony response around the plate. Six of the 11 horses treated by plate fixation returned to their intended use. The authors recommend consideration of plate fixation techniques for repair of fractures in the proximal third of the splint bone.     

Subchondral cystic lesions of the proximal extremity of the tibia in horses: 12 cases (1983-2000)

OBJECTIVE: To determine clinical and radiographic features of subchondral cystic lesions (SCL) of the proximal extremity of the tibia in horses that could be used to classify these lesions as being related to osteochondrosis or osteoarthritis and to evaluate results of surgical debridement. DESIGN: Retrospective study. ANIMALS: 12 horses with 14 SCL. PROCEDURE: Medical records and radiographs obtained before and after treatment were reviewed. RESULTS: In 6 young horses (8 lesions), SCL were considered to be related to osteochondrosis; all involved the lateral tibial condyle. The remaining 6 horses were mature and had radiographic evidence of osteoarthritis in addition to SCL. Arthroscopic debridement was performed in 4 horses in which lesions were considered to be a result of osteochondrosis and in 3 horses with osteoarthritis. Three horses in which SCL were considered to be a result of osteochondrosis performed athletically after debridement. Two horses with moderate osteoarthritis returned to work after arthroscopic debridement but at a lower level of athletic performance. One horse with SCL related to osteochondrosis responded to medical treatment and went on to race. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that arthroscopic debridement of SCL is feasible in horses in which lesions involve the cranial portion of the lateral or medial tibial condyle, and that treated horses may be able to perform athletically.     

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.     

Incomplete linear tibial fractures in two horses

Incomplete linear tibial fractures were identified in two horses with the aid of scintigraphy. Both horses were treated successfully by strict stall confinement, and both returned to normal athletic activity. Scintigraphy can be used to facilitate the generally difficult diagnosis of incomplete tibial fractures.     

Arthroscopic removal of dorsoproximal chip fractures of the proximal phalanx in standing horses

OBJECTIVE: To report a technique for, and outcome after, arthroscopic removal of dorsoproximal chip fractures of a proximal phalanx in standing horses. STUDY DESIGN: Retrospective study. ANIMALS OR SAMPLE POPULATION: A total of 104 horses, 1 to 13 years of age, with a dorsoproximal chip fracture of a proximal phalanx. METHODS: Horses were restrained in standing stocks and sedated with intravenous xylazine, detomidine, or a combination of both drugs. Local analgesia was achieved with 2% mepivacaine administered intra-articularly and by subcutaneous infiltration in a crescent-shaped block dorsal to the fetlock. Sterile drapes were placed on the surgical field, and impervious drapes were used on the hoof and floor. Arthroscopic portals were created in the dorsal pouch of the metacarpophalangeal or metatarsophalangeal joints to remove chip fractures. Statistical analysis was performed on race records for all Thoroughbred racehorses and compared with previously published studies. Operative and hospitalization times were compared with those of the general hospital population, and risks associated with general anesthesia were examined. RESULTS: No major operative or postoperative complications occurred. Ninety-one percent of racehorses raced after surgery with 78% returning to race at the same or higher level. CONCLUSION: Standing arthroscopic surgery can be performed successfully to remove dorsoproximal chip fractures of the proximal phalanx. CLINICAL RELEVANCE: Standing arthroscopic surgery is a valid alternative treatment for experienced surgeons to avoid the expense and potential risks associated with general anesthesia.     

Characterisation and cardiac directed differentiation of canine adult cardiac stem cells

A multicentre study of 285 cases was performed to enhance the management of distal phalangeal fractures on the basis of clinical evidence. The outcome after treatment was available for 223 of the cases. Horses with a non-articular type I fracture had a better prognosis (91.7%) for return to original or expected level of use than horses with an articular type II or III fracture (69.6% and 74.1%, respectively). The prognosis for types IV and V fractures was fair (57.7% and 57.1%, respectively) and for type VI good (80%). Horses with a hindlimb fracture had a significantly greater chance of a successful outcome. No significant association between age or time to start treatment and success rate was noted. The best treatment option for types I-III fractures was a conservative approach (box rest). Type IV fractures were best treated by arthroscopic removal of the fragment. Immobilisation of the hoof did not seem to influence outcome. Radiological findings and clinical healing were not accurately correlated and the re-commencement of training should be based on clinical rather than radiological findings. Complete osseous union of the fracture was not essential for a successful return to athletic activity.     

Size and geometry of apical sesamoid fracture fragments as a determinant of prognosis in Thoroughbred racehorses

Reason for performing study: Analysis was performed to examine a method for refining the preoperative prognosis for horses that had surgery to remove apical fractures of the proximal sesamoid bones (PSBs). Objectives: To determine if: 1) there was a difference in size or configuration of apical fractures between the different anatomical locations of the PSBs, which have been shown to affect the prognosis; and 2) the size or configuration could predict the prognosis for racehorses with these fractures. Methods: The study included 110 weanlings and yearlings and 56 training racehorses that underwent surgery to remove apical PSB fractures. Radiographs of the fractures were used for measurement of the abaxial and axial proportion and the abaxial to axial ratio, and race records were used to determine average earnings per start (AEPS) and total post operative starts. Analysis of variance and regression statistics were used to compare the fragment sizes between the specific PSBs on each of the limbs and compare size and configuration of the fractures to prognosis. Results: There was a significantly larger abaxial to axial ratio (more transverse fracture) for the forelimb medial sesamoids than for all other sesamoids in untrained racehorses (P = 0.03). There were no other significant differences in size. There was no relationship between fracture size or configuration and AEPS nor total post operative starts. Conclusions: Apical fractures in weanlings and yearlings tend to be more transverse in the forelimb medial PSBs than the other PSBs. Apical fracture size and geometry does not determine prognosis for apical sesamoid fractures. Potential relevance: Horses that undergo surgery to remove larger apical fractures of the PSBs do not have a worse outcome than those horses with smaller fractures.     

Arthroscopic removal of fractures of the lateral malleolus of the tibia in the tarsocrural joint: A retrospective study of 13 cases

There is limited information on the treatment of lateral malleolus (LM) fractures in the horse, with no previously published case series for the outcome following arthroscopic removal of such fractures. This report reviews and evaluates findings of a retrospective study of 13 horses admitted to a private equine referral hospital over a 10 year period (1999–2009) that underwent arthroscopic removal of fractures of the LM. Hospital records were reviewed and details including patient history, aetiology of the fracture and limb affected, results of all diagnostic tests and surgical reports were documented. Performance information concerning Thoroughbred horses that went onto race post operatively was collected using an online database. Owners and trainers were contacted regarding the return to performance for non‐Thoroughbred cases or those that did not go onto race post operatively. Of the 13 horses presented, 12 were Thoroughbreds, 9 of which were National Hunt racehorses and 3 were Flat racehorses. The other horse in the study was used for general purpose riding. All cases presented with an acute unilateral fracture. Eleven of the 13 had >6 months post operative follow‐up and all were nonlame. Of the 12 Thoroughbreds, 10 have raced again, a total of 104 times (median 5 times). The median time from surgery to return to racing was 241 days (180–366 days). It is concluded that horses with fractures of the LM have an excellent prognosis for return to full athletic performance following arthroscopic debridement; and that arthroscopic fragment removal is an appropriate treatment method for fractures of the LM.     

Comminuted First Phalanx Fractures in 30 Horses: Surgical vs. Nonsurgical Treatments

Comminuted first phalanx fractures were diagnosed in 30 horses. One leg was involved in each horse. Five horses were presented with open fractures. Nine horses had a portion of intact cortex (strut) extending from the proximal to distal joint. Ten horses were euthanized, including one with an open fracture, without treatment. The remaining 20 horses were treated by open reduction with a neutralization plate (8 horses, including one with an open fracture), open reduction with lag screw fixation (3 horses), lag screw fixation through stab incisions (2 horses), external coaptation with a cast (3 horses), and external skeletal fixation using a weight supporting shoe (4 horses, including 3 with open fractures).
Thirteen horses were euthanized following treatment because of persistent infection (9), chronic lameness (2), and third metacarpal bone fractures (2). Seven horses survived longer than 1 year after treatment. Six were lame and used as breeding animals, and one horse went on to race successfully. All four horses with open fractures that were treated were subsequently euthanized.
Significantly more horses with an intact strut of bone survived after treatment (4 of 7 [57%]) when compared to horses without an intact strut of bone that were treated (3 of 13 [23%]) (p < 0.05).
Invasive surgical approaches used for the repair of comminuted first phalanx fractures in this study were associated with an unacceptable infection rate (55%). Techniques involving less trauma to the compromised soft tissue around the fracture should afford a better chance for a successful outcome.