# Biomechanical effects of cranial closing wedge osteotomy on joint stability in normal canine stifles: an ex vivo study

## TL;DR

This study examines how a surgical technique called CCWO affects joint stability in dog knees, both with and without a key ligament.

## Contribution

The study provides new biomechanical insights into CCWO's effectiveness in stabilizing canine stifle joints under various conditions.

## Key findings

- CCWO reduced compressive displacement but increased drawer and rotational displacement in canine stifle joints.
- CCWO combined with CrCL transection worsened joint instability during drawer tests.
- CCWO is most effective for stabilization when the cranial cruciate ligament is intact.

## Abstract

Cranial closing wedge osteotomy (CCWO) is a functional stabilisation technique for cranial cruciate ligament (CrCL) ruptures. This biomechanical study aimed to evaluate the influence of CCWO on the stability of the stifle joint.

Eighteen Beagle stifle joints were divided into two groups: control and CCWO. The stifle joints were analyzed using a six-degree-of-freedom robotic joint biomechanical testing system. The joints were subjected to 30 N in the craniocaudal (CrCd) drawer and proximal compression tests and 1 Nm in the internal–external (IE) rotation test. Each test was performed with an extension position, 135°, and 120° of joint angle.

The stifle joints were tested while the CrCLs were intact and then transected.

In the drawer test, the CCWO procedure, CrCL transection, and stifle joint flexion increased CrCd displacement. The CCWO procedure and CrCL transection showed an interaction effect. In the compression test, the CCWO procedure decreased and CrCL transection and stifle joint flexion increased displacement. In the IE rotation test, CCWO, CrCL transection, and stifle joint flexion increased the range of motion.

CCWO was expected to provide stability against compressive force but does not contribute to stability in the drawer or rotational tests. In the CCWO-treated stifle joint, instability during the drawer test worsened with CrCL transection. In other words, performing the CCWO procedure when the CrCL function is present is desirable for stabilizing the stifle joint.