Locking Plate Fixation for Canine Acetabular Fractures

Comparison of Bending Stiffness between String of Pearls Plate-Bone Substitute Constructs with and without Bending Tees in a Fracture Gap Model

OBJECTIVE

 The aim of this study was to compare the bending properties of String of Pearls plate-bone substitute constructs with and without bending tees in the nodes over a simulated fracture gap. It is hypothesized that the constructs with tees will have higher bending stiffness.

STUDY DESIGN

 Acetal polymer tubes and 12-hole, 3.5-mm String of Pearls plates were used to create plate-bone substitute constructs simulating stabilization in a bridging fashion over a 45-mm gap. Twenty-four constructs were made with 12 containing tees in the nodes over the fracture gap. Single-cycle load-to-failure 4-point bending was performed in mediolateral and craniocaudal planes. Bending stiffness was compared with a t-test (p < 0.05).

RESULTS

 All plate-bone substitute constructs had a permanent loss of structural integrity via plastic deformation of the plate. The bending stiffness (mean ± standard deviation) of the craniocaudal group was 59.11 ± 1.98 N/mm with tees and 59.25 ± 1.69 N/mm without tees (p = 0.88). In the mediolateral group, the bending stiffness was 43.17 ± 0.75 N/mm with tees and 41.09 ± 0.91 N/mm without tees (p = 0.0042).

CONCLUSION

 In 4-point bending, the plate-bone substitute constructs with tees had equivalent bending stiffness in the craniocaudal plane and increased bending stiffness in the mediolateral plane. However, with a small absolute difference in values, the clinical significance is unclear. Future studies for cyclic bending, torsional, and axial compression tests should be performed to further investigate the value of tees in the nodes over a comminuted or gap fracture repaired in a bridging fashion.

A Bilateral Acetabular Physeal Fracture Treated with External Fixation in an Immature Cat

This study aimed to assess the outcome of a bilateral acetabular physeal fracture treated with external fixation in an immature cat, a surgical technique not usually employed in immature patients. The fixator took 40 days, and it was removed after radiographic bone healing was achieved. No significant complications related to the technique were identified, and the outcome was classified as good based on the functional assessment and pain scales employed. The use of external fixation for stabilising acetabular fractures in immature cats should be considered a viable technical option, especially for minimally invasive stabilisation.

Retrospective Assessment of Thirty-Two Cases of Pelvic Fractures Stabilized by External Fixation in Dogs and Classification Proposal

The goals of this study were to evaluate the outcomes of bone healing, patient comfort during the treatment, functional results, and complications in pelvic fractures treated with external fixation, as well as to propose a classification system for the applied external frames. A total of thirty-two canine patients with pelvic fractures of different origins were treated. To provide a better reference for the frames used, an alphanumeric classification system was developed, detailing the frame structure and the number and location of the pins used. In this study, eighty-six fractures were treated in the 32 patients of this work, with an average fixation time of 9.88 ± 4.15 weeks. No major complications were detected in this case cohort, and the outcomes were rated at 9.46 based on a visual assessment scale for the patient's comfort during treatment. Outcomes graded as excellent and good were 96%. The use of external fixation for stabilization of pelvic fractures should be considered as a technical option, especially for minimally invasive stabilization of complex fractures, either as a primary or secondary stabilization.

Minimally invasive repair of acetabular fractures in dogs: Ex vivo feasibility study and case report

OBJECTIVE

To describe and evaluate minimally invasive repair of acetabular fractures in dogs using plates contoured to 3D-printed hemipelvic models.

STUDY DESIGN

Ex vivo feasibility study and case report.

SAMPLE POPULATION

Adult canine cadavers (n = 5); 8 year old male neutered Chihuahua.

METHODS

Bone plates were contoured to 3D printed hemipelvic models derived from computed tomographic scans of each dog. In cadavers, acetabular, ischial, and pubic osteotomies were performed. A small craniolateral approach to the ilial body and a caudal approach to the ischium were made and connected through epiperiosteal tunnels. Under fluoroscopic guidance, fractures were reduced, and precontoured bone plates were applied with locking screws. Postoperative computed tomographic images were used to assess fracture gaps, step defects, and pelvic angulation. Cadavers were dissected for subjective assessment of sciatic nerve injury. Radiographic and clinical follow up was acquired for the clinical case.

RESULTS

Small fracture gaps (<2 mm) and step defects (<1 mm), low pelvic angulation (<5°), and minimal (none n = 4 and mild n = 1) sciatic nerve injuries were observed in cadaver testing. There was slight (~1 mm) medial displacement of the pubic segment and good functional outcome for the clinical case, with radiographic healing documented at 3 months postoperatively.

CONCLUSION

Minimally invasive acetabular fracture repair in dogs with the aid of 3D printing was feasible and accurate.

CLINICAL SIGNIFICANCE

Minimally invasive repair techniques assisted by 3D printing may be applicable for acetabular fractures in dogs. The technique should be evaluated further before routine use can be recommended.

Locking Compression Plate Fixation of Feline Acetabular Fractures: Application, Complications and Perioperative Outcome

OBJECTIVES

 The aim of this study was to report the use, complications and perioperative outcome of locking compression plates (LCP) for acetabular fracture fixation in feline patients.

STUDY DESIGN

 Medical records were reviewed for cats presented with acetabular fractures between 2011 and 2019. Only cases that involved open reduction and internal fixation with at least one LCP and had a minimum of 5-week postoperative follow-up were included. Long-term follow-up was based on the Feline Musculoskeletal Pain Index.

RESULTS

 Fifteen cats with 15 acetabular fractures met the inclusion criteria. Locking compression plates were used as a sole method of fixation in 11/15 cases, while with other ancillary implants in 4/15 cases. There were two minor complications related to the LCP consisting of a single screw backing out. Two major perioperative complications not related to the locking implants were described and required further surgical treatment. At the last clinical follow-up (median 46 days: 38-88 days), function was described as full for 7/15 cats, and acceptable for 8/15 cats. The Feline Musculoskeletal Pain Index questionnaire was completed by 9/15 owners at a median of 2,332 days; all owners reported their cats had minimal impairment.

CLINICAL SIGNIFICANCE

 Based on our results, LCP is a suitable implant for acetabular fracture fixation in cats, associated with a satisfactory outcome. Complications were similar to previously reported with other methods.

Humeral intracondylar fissures in French bulldogs

BACKGROUND

French bulldogs have previously been reported to be at an increased risk of developing humeral condylar fractures (HCF). Humeral intracondylar fissures (HIF) are thought to be a predisposing factor for HCF occurrence in skeletally mature dogs particularly when the fracture occurs during normal activity. We hypothesised that HIF may be a predisposing factor for HCF in French bulldogs.

METHODS

A retrospective case series of nine French bulldogs that had sustained HCF and where CT was performed prior to surgery.

RESULTS

Five of the fractured humeri had sclerosis adjacent to the fracture site. Six of the contralateral intact humeri were diagnosed with HIF on the basis of a partial (2/6) or complete (4/6) hypoattenuating area extending between the distal articular surface and the supratrochlear foramen in the sagittal plane, with adjacent sclerosis (6/6).

CONCLUSIONS

Recognition of sclerosis at the intracondylar fracture surface on CT can prompt suspicion that HIF preceded HCF. A predisposing HIF has potentially great clinical significance for this breed if we draw parallels with breeds such as the springer spaniel for whom HIF and HIF-associated condylar fracture is well documented.

Radiographically confirmed outcomes after fracture repair with a PLS polyaxial locking system in 40 dogs and cats

OBJECTIVE

To report radiographic findings and complications after fracture repair with a new polyaxial locking plate system (PLS polyaxial locking system; Aesculap/B Braun, Tuttlingen, Germany) in dogs and cats.

STUDY DESIGN

Retrospective case review from four veterinary practices.

SAMPLE POPULATION

Twenty-six dogs and 14 cats (40 long bone fractures).

METHODS

Medical and radiographic records of dogs and cats with long bone fractures treated with the PLS were reviewed. Cases were included when operative records were complete and included documentation of radiographic union or complications. Phone interviews of owners were performed for long-term follow-up. Ancillary methods of fracture fixation and associated complications were recorded.

RESULTS

Only two complications were recorded, one of which required a revision surgery. Radiographic follow-up was performed for all fractures. Radiographic union without complications was achieved in 38 of 40 (95%) fractures. Radiographic union was documented before 60 days in 19 of 40 (47.5%) fractures, between 61 and 90 days in 15 of 40 (37.5%) fractures, and after 90 days in six of 40 (15%) fractures. A functional union was observed at a mean time ± SD of 70.8 ± 38.9 days (range, 32-182). One or more ancillary fixation methods were used in 27 of 40 (67.5%) fractures.

CONCLUSION

The PLS polyaxial locking system was often used with adjunct fixation in this series, and radiographically confirmed healing without complications was documented in most cases.

CLINICAL SIGNIFICANCE

Use of the PLS can result in high success rates for fracture repair in dogs and cats, but ancillary fixation should be strongly considered.