Vet Comp Orthop Traumatol 2019; 32(06): 483-491
DOI: 10.1055/s-0039-1692189
Clinical Communication
Georg Thieme Verlag KG Stuttgart · New York

A Retrospective Study Using the String of Pearls Tibial Plateau Levelling Osteotomy Locking Plate for the Treatment of Cranial Cruciate Ligament Disease

Ross E. McGregor
1  Northside Veterinary Specialists, Sydney, Australia
Eugene A. Buffa
1  Northside Veterinary Specialists, Sydney, Australia
Christopher J. Tan
2  Sydney Veterinary Emergency and Specialists, Sydney, Australia
Mark A. Schembri
3  Post Graduate Foundation in Veterinary Science, The University of Sydney, Sydney, Australia
Caro-Anne Badcock
4  Shimsco Consulting, Wootton, Australia
Alen Lai
5  Northshore Veterinary Specialist Centre, Sydney, Australia
› Author Affiliations
Funding None.
Further Information

Publication History

24 April 2018

27 April 2019

Publication Date:
21 June 2019 (online)


Objective The aim of this study was to describe the use of String of Pearls (SOP) tibial plateau levelling osteotomy (TPLO) locking plates for the treatment of cranial cruciate ligament disease and retrospectively assess osteotomy healing, tibial plateau angle (TPA) change (c) and overall complication rates.

Methods Medical records and radiographic studies of 170 SOP TPLO surgical procedures were analysed. Radiographic measurement of TPAc and osteotomy union was determined 6 to 8 weeks postoperatively. Intra- and postoperative major and minor complications were identified. Factors influencing TPAc, osteotomy union and complications were assessed.

Results Mean (standard deviation) TPAc was 1.3° (1.61) and median osteotomy union was graded as 2 (26–50%) union. Improved osteotomy union was associated with retention of the antirotational pin (odds ratio [OR]: 2.3; 95% confidence interval [CI]: 1.3–4; p = 0.005) and reduced TPAc (OR: 0.8; 95%CI: 0.66–0.97; p = 0.02). Complications occurred in 42 (24.7%) procedures with 11 (6.5%) considered major and 31 (18.2%) minor.

Clinical significance The use of the SOP TPLO plating system resulted in a median grade 2 (26–50%) radiographic osteotomy union score at 6 to 8 weeks' follow-up, less than previous TPLO locking plate studies. Osteotomy union was associated with retention of the antirotational pin and reduced TPAc. Major and minor complication rates were marginally greater than recent locking plate studies with fibular fracture and screw loosening common complications. The use of SOP TPLO plates is cautioned and further study is warranted.

Animal care guideline

No handling or use of animals for experimentation was performed in this study.

Author Contribution

R McGregor, E Buffa, C Tan and A Lai participated in the study conception, design, drafting and revision of the manuscript. C Badcock and M Schrembi participated in data acquisition, analysis and interpretation as well as drafting and revision of the manuscript. All authors approved the version before submission.


All authors report no conflict of interest related to this study and have no personal or financial relationship with other organizations or persons that could inappropriately bias or influence the contents of this paper.