Epidemiology of fractures: The role of kick injuries in equine fractures

Closed laceration of the trachea, esophagus and guttural pouches in a mare caused by blunt trauma

A mare was admitted for progressive swelling of the neck, lethargy and anorexia. Radiography revealed perilaryngeal, peritracheal, and periesophageal emphysema. Endoscopy revealed pharyngeal and tracheal roof collapse, and a small laceration on the trachea. Treatment with antimicrobials, fluids, and flunixin was initiated. To prevent exacerbation of the emphysema, temporary tracheostomy was performed. Clipping for the tracheostomy revealed a hoofprint mark on the ventral neck. Subsequent endoscopies revealed laceration of the esophagus and guttural pouch septum communicating with the visceral compartment of the neck. Four days after admission, an esophagostomy was performed to prevent leakage of ingesta into the neck and allow feeding. Complications occurred: Deep cervical infection requiring surgical drainage; Esophageal impaction with shavings on one occasion causing extensive mucosa erosions; Laminitis managed with restricted physical activity and corrective farriery. Tracheostomy tube removal, esophagostomy tube removal, and patient discharge occurred 10, 36 and 51 days after admission, respectively. The mare did well after discharge and returned to competing in children's showing classes. Blunt trauma to the neck can lacerate the trachea, esophagus and guttural pouches causing emphysema and deep cervical infection, which can be treated with antimicrobials, temporary tracheostomy, temporary esophagostomy, surgical drainage, and supportive care.

Total removal of the fourth metacarpal bone in an Icelandic horse

Fractures of the splint bones are the most common fractures in horses. Various treatment options for splint bone fractures (MC/MT II and IV), including conservative and surgical management, have been described. This report describes an acute splint bone fracture due to external trauma in a 17-year-old Icelandic mare. The fracture was diagnosed as an open multifragment fracture of the proximal third of the fourth metacarpal bone (MCIV) in the right front limb. Surgery was performed with the horse under general anaesthesia. The distal fragments were removed, and the distal part of the proximal remnant splint bone was cut with an osteotome. During the postoperative period, a routine x-ray-control two days after surgery showed a dislocated fracture of the remaining proximal part of the fourth metacarpal bone. In a second surgery, the proximal part of MCIV was entirely removed. After a reconvalescence period of 5 month, the horse reached her previous level of performance as a leisure horse. The mare is still free of lameness 6 years after the incident.

Treatment of a Mandibular Diastemal Fracture Using Locking Compression Plate and Cerclage Wire in a Mare

This report describes the combination of two surgical fracture repair techniques and the postoperative management of a mandibular diastemal fracture in a two-year-old mare. The mare was referred to a veterinary hospital with a laceration over the body of the right mandible. Radiographic assessment revealed two mesial fracture lines involving the second premolar tooth and a ventrally displaced bone fragment. The mare was treated under general anesthesia and the fracture was corrected using open reduction and plate fixation. A 3.5 mm narrow 15-hole locking compression plate with seven locking screws were used in a bridge form. Cerclage wire was also used to anchor the incisor teeth to the second and third premolar teeth. The cerclage wire and incisor teeth were covered with polymethylmethacrylate to prevent implant failure and avoid injury to the oral mucosa. Implants were removed 55 days after surgery and the mare was discharged from hospital five days later. The mare returned for cerclage wire removal after 90 days and was allowed to resume exercise thereafter. The combination of two surgical techniques, proper implant choice and appropriate postoperative management, including use of pelleted feed, contributed to successful bone healing and return to function.

A review of equine tibial fractures

Equine tibial fractures are relatively infrequent in racing and non-racing sport horses, but limitations in successful treatment of tibial fractures in adult horses result in relatively high mortality compared with other musculoskeletal injuries. The aetiology of tibial fracture can be classified into two general categories: traumatic impact or fatigue failure. Tibial stress fractures, also known as fatigue fractures, are often rated as the second most common stress fracture in racing Thoroughbreds; young age, early stage in race training, and initiation of training after a period of rest are the reported risk factors. Both impact and fatigue fracture propagation are dependent on the magnitude of force applied and on the local composition/alignment of mineralised collagen in the tibial lamella. Extensive research has characterised the pattern of strain distribution and stress remodelling within the equine tibia, but in vivo measurement of load and angular moments are currently not feasible. Further research is warranted to correlate biomechanical theory of tibia fatigue fracture propagation with current histopathological data. Preventative measures for fatigue fractures aim to optimise diagnostic efficiency, reduce the interval between injury and diagnosis and modify racing and training conditions to reduce non-specific fracture risk. Treatment options for complete tibial fractures in adult horses are limited, but with careful case selection, successful outcomes have been reported after open reduction and internal fixation. On the other hand, tibial stress fractures and minimally displaced incomplete fractures are typically treated conservatively and have good prognosis for athletic recovery. This review aims to describe the current literature regarding tibial fracture aetiology, prevalence, risk factors, fracture biomechanics, treatment, prognosis and prevention.

Simulated Kick Injury to the Mandible in Horses: Study of Fracture Configurations and Physical Parameters of the Impact

OBJECTIVE

 The goal of this study was to generate mandibular fractures in three regions of the diastema using a metal impactor to simulate a kick from a horse and to determine the mean deceleration in the initial phase of the impact event, the maximum contact force, the impact energy necessary to create a fracture and the duration of the impact.

STUDY DESIGN

 Thirty heads of horses aged between 5 and 20 years and euthanatized for various reasons were used. The heads were attached to a steel bar at the occiput at an axial angle of 45 degrees so that the body of the mandible was positioned horizontally and directly under the trajectory of the impactor. A 2 kg solid impactor was dropped with velocities of 6 to 14 m/s to simulate a kick from a horse. The impact was recorded using a high-speed video camera with a frame rate of 30,000 frames per second. Radiographs of the heads were obtained before and after the simulated kick.

RESULTS

 Mandibular fractures with configurations similar to those seen in clinical practice were generated at all three locations. The mean deceleration increased with impact velocity and with more cranially located impact positions. Absorbed energy increased with increasing impact velocity when no fracture was generated.

CONCLUSION

 The susceptibility to experimental fracture of the diastema increased from rostral to caudal locations, which is most probably caused by decreasing mandibular bone strength and an increase in the curvature at the lateroventral aspect of the mandible in that region. Physical parameters depended on fracture occurrence and type.

Surgical management of a Salter-Harris type I proximal physeal fracture of the tibia in a foal: a case report

Background

One of the traumatic fractures occurring in the hindlimb of the foals is physeal fractures of the tibia. The most common type of proximal tibial fracture in foals is reported to be Salter-Harris type II.

Case presentation

This case report describes the history, clinical signs, radiographic findings, and surgical management of a proximal physeal fracture of the tibia due to the kick trauma in a 2-weeks-old Kurdish female foal, with signs of left pelvic limb lameness, valgus deviation with non-weight-bearing, non-mobility in stifle region and crepitation in the affected area. In this case, radiography was utilized to confirm the fracture and detect the exact location of the fracture fragments. The Salter-Harris type I accompanied by tibial tuberosity fracture was diagnosed. In this case, a size 4.5 mm seven-hole, T-plate, and cortical bone screws were employed to fix the physeal fracture, and a cortical bone screw was utilized to fix the tibial tuberosity in the normal position. Case follow-up during two months showed no significant complications, and the patient was fully recovered (no lameness anymore).

Conclusions

To our knowledge, this is the first report of Salter-Harris type I fracture in proximal tibia accompanied by tibial tuberosity fracture in a foal treated by a T-plate implant. A cortical screw in lag fashion for tibial tuberosity was utilized in this case for the first time, and the results were satisfying. T-Plate fixation can be recommended as an effective surgical treatment for proximal tibial fractures in foals.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12917-022-03285-6.

Influence of a novel scaffold composed of polyurethane, hydroxyapatite, and decellularized bone particles on the healing of fourth metacarpal defects in mares

OBJECTIVE

To determine the effect of a novel scaffold, designed for use in bone regeneration, on healing of splint bone segmental defects in mares.

STUDY DESIGN

In vivo experimental study.

SAMPLE POPULATION

Five adult mares (4-10 years old; mean weight, 437.7 kg ± 29 kg).

METHODS

Bilateral 2-cm full-thickness defects were created in the fourth metacarpal bones (MCIV) of each horse. Each defect was randomly assigned to either a novel scaffold treatment (n = 5) or an untreated control (n = 5). The scaffold was composed of polyurethane, hydroxyapatite, and decellularized bone particles. Bone healing was assessed for a period of 60 days by thermography, ultrasonography, radiography, and computed tomography (CT). Biopsies of each defect were performed 60 days after surgery for histological evaluation.

RESULTS

On the basis of radiographic analysis, scaffold-treated defects had greater filling (67.42% ± 26.7%) compared with untreated defects (35.88% ± 32.7%; P = .006). After 60 days, CT revealed that the density of the defects treated with the scaffolds (807.80 ± 129.6 Hounsfield units [HU]) was greater than density of the untreated defects (464.80 ± 81.3 HU; P = .004). Evaluation of histology slides provided evidence of bone formation within an average of 9.43% ± 3.7% of the cross-sectional area of scaffolds in contrast to unfilled defects in which connective tissue was predominant throughout the biopsy specimens.

CONCLUSION

The novel scaffold was biocompatible and supported bone formation within the MCIV segmental defects.

CLINICAL SIGNIFICANCE

This novel scaffold offers an effective option for filling bone voids in horses when support of bone healing is indicated.

Plate Removal after Internal Fixation of Limb Fractures: A Retrospective Study of Indications and Complications in 48 Horses

OBJECTIVE

 The aim of this study was to determine the indications for, and complications of, plate removal surgery in horses that underwent internal fixation of limb fractures.

STUDY DESIGN

 Medical records of horses presented to our hospital between 1990 and 2015 for the removal of plates after treatment of limb fractures were reviewed. Data collected at the time of initial presentation, including signalment, history, fracture features and treatment and information about the indications, timing and complications of implant removal were reviewed.

RESULTS

 The most common bones involved were the ulna (n = 19) and third metacarpal and metatarsal bones (n = 14). A total of 63 plates were removed from 48 horses during 53 separate surgeries, and the complication rate was 6/48; six horses had complications related to implant removal, which included persistent infection (n = 1) and refracture (n = 5). Complications related to implant removal were associated with comminuted fractures (p = 0.002), age > 3 years (p = 0.016) and the presence of surgical site infection (p = 0.001).

CONCLUSION

 Plate removal after fracture healing is necessary in patients with implant-associated clinical signs. There is a strong relationship between the complication rate and the degree of comminution of the original fracture, increasing age and the presence of surgical site infection. The surgeon must be aware of these risk factors when planning plate removal.