Computed tomography-guided cannulated lag screw placement for treatment of ununited anconeal process: surgical technique, clinical outcome, and radiographic healing in 7 dogs

J Am Vet Med Assoc. 2024 Feb 14;262(5):1-7. doi: 10.2460/javma.23.10.0569. Print 2024 May 1.

Abstract

Objective: A novel technique and outcomes for correction of ununited anconeal process (UAP) via CT-guided cannulated lag screw placement in 7 canine patients is described.

Animals: Cases of canine patients (7 patients/8 elbows) diagnosed with UAP that subsequently underwent CT-guided cannulated lag screw placement were retrospectively evaluated.

Clinical presentation: Pre- and postoperative exam findings (lameness and pain on range of motion) are presented. Preoperative radiographs and postoperative radiographs at 2 time points (approximately 8 weeks postoperatively and at the time of the most recent imaging; mean, 221 days; range, 85 to 828 days) were scored for degree of arthrosis and postoperative radiographs were evaluated for radiographic union. Complications were reported and stratified by severity and time postoperatively.

Results: Minor perioperative (0 to 3 months postoperatively) complications included seroma formation (n = 1) and major perioperative complications involved development of surgical site infections (2), with 2 patients requiring implant removal in the perioperative period (44 and 82 days postoperatively). All patients achieved radiographic union, defined as partial or complete bridging of the anconeal process to the ulna within the study period (mean radiographic follow-up time 221 days postoperatively; range, 85 to 828 days; 5/8 joints partial bridging, 3/8 joints complete bridging) and pre- versus postoperative elbow arthrosis scores remained static in all patients.

Clinical relevance: The case outcomes described support the use of CT-guided cannulated lag screw placement as a feasible option for treatment of UAP.

Keywords: cannulated screw; computed tomography; dog; elbow dysplasia; ununited anconeal process.