Factors influencing stifle stability in canine limb press models: A systematic review and meta-analysis.

Limb press models have been widely used to explore aspects of canine stifle stability and to inform surgical practice. This systematic review aimed to synthesize test conditions, periarticular forces, and stability measures in canine limb press models for comparison with in vivo measurements. Six databases (EMBASE, Ovid MEDLINE, CAB abstracts, Agricola, Scopus, and Web of Science) were searched from inception to 17.03.2025. Peer-reviewed experimental studies using static, axially loaded, whole-limb constructs and reporting cranial tibial translation, rotation, and/or periarticular forces were eligible for inclusion. Twenty-three articles were included, reporting results from 368 healthy limbs of dogs of various breeds. Most (17/23) simulated stance during walking but landmarks for limb angulation were frequently poorly described or deviated from those used in cited studies. Cranial cruciate ligament transection caused mean cranial translation of 14.6 mm and mean internal rotation of 13.1°. Cranial translation and rotation were improved by osteotomy techniques, but data were heterogeneous, sample sizes were often small, and reporting standards inconsistent. Key data regarding quadriceps, gastrocnemius, or cranial thrust forces were extremely limited. This review identified potentially serious knowledge gaps regarding simulated muscle and periarticular forces, and concerns over limb angulation. Further evaluation of ex vivo models is warranted to determine the likely validity of currently reported models. If current models are shown to simulate muscle forces which do not reflect expected in vivo loading, this could help explain the difference between in vivo and ex vivo assessments of joint stability following surgeries such as TPLO and TTA.