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

Successful centralisation technique for treatment of post-traumatic absence of the radial shaft in a dog

This report describes a centralisation procedure for the treatment of a radial non-union, characterised by extensive bone loss and an intact ulna, in an 18-month-old toy poodle. A lateral approach to the radius/ulna shafts was realised and, after debridement of the non-union site, an ulnar osteotomy was performed proximal to the styloid process of the ulna. Transposition of the distal fragment of the radius to the distal end of the osteotomised proximal segment of the ulna was performed and the stabilisation was obtained using a locking plate with proximal screws in the ulnar shaft and distal screws in the radius epiphysis. The patient achieved bone union in 10 weeks and the last evaluation, performed 112 weeks postoperatively, showed a full return to pre-injury function. Based on the results of this report, the centralisation was effective in the treatment of post-traumatic absence of the radial shaft in a dog.

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.

What Is the Cost of Off-Axis Insertion of Locking Screws? A Biomechanical Comparison of a 3.5 mm Fixed-Angle and 3.5 mm Variable-Angle Stainless Steel Locking Plate Systems

OBJECTIVE

 The aim of this study was to evaluate the effect of screw insertion angle and insertion torque on the mechanical properties of a 3.5 fixed-angle locking plate locking compression plate (LCP) and 3.5 variable-angle locking plate polyaxial locking system (PLS).

METHODS

 In the LCP group, screws were placed abaxially at 0, 5 and 10 degrees. In the PLS group, screws were placed at 0, 5, 10, 15 and 20 degrees abaxially. The insertion torque was set to 1.5 and 2.5 Nm in the LCP and PLS groups respectively. A load was applied parallel to the screw axis, and the screw push-out force was measured until the locking mechanism was loosened.

RESULTS

 The 3.5 LCP showed higher push-out strength than the 3.5 PLS when the screws were placed at 0 degree regardless of the insertion torque. The off-axis insertion of 3.5 LCP locking screws resulted in a significant decrease in push-out strength (p < 0.05). A higher insertion torque value significantly increased the screw holding strength for the 3.5 LCP (p < 0.05). The 3.5 PLS system had a significantly higher push-out force when the screws are at 0 degree than at 5, 10 and 15 degrees, and 20 degrees (p < 0.05) at any given insertion torque. An increase in the insertion torque did not have a significant effect on the push-out strength of the 3.5 PLS locking system.

CONCLUSION

 The 3.5 PLS is more sensitive to the screw insertion angle than to the insertion torque, whereas the 3.5 LCP is affected by both factors. Placing 3.5 LCP locking screws off-axis significantly reduces the screw holding strength; therefore, this approach has to be avoided. The findings of our research indicate that a 1.5 Nm torque can be used for a 3.5 PLS.