Suture Anchor Technique Shows Superior Biomechanical Properties Compared With Transtibial Pull‐Out for Posterior Medial Meniscus Root Repairs: A Systematic Review

PURPOSE: To compare the biomechanical properties between transtibial pull-out (TP) and suture anchor (SA) techniques for treating posterior medial meniscal root tears (PMMRTs). METHODS: The PubMed, Embase, and Cochrane database were searched for studies published before April 20, 2025. Inclusion criteria were: (1) comparative biomechanical studies evaluating SA vs TP for PMMRT repair; (2) studies using cadaveric or animal specimens; and (3) studies written in English or with an English translation. Exclusion criteria included single-technique studies, anterior meniscal root studies, studies with combined ligament injuries, and clinical/observational human studies. Quality assessment of included studies was performed using the Biomechanics Objective Basic science Quality Assessment Tool. Extracted data from the studies included study characteristics and experimental data, such as repair techniques (suture materials, suture configurations and anchor types), types of biomechanical testing, and relevant outcome parameters (displacement, load, stiffness, contact area, contact pressure, failure modes). The results from different studies were compared. RESULTS: This study systematically reviewed 7 biomechanical studies (including 165 porcine knee joints and 44 human cadaver knee joints) to compare the biomechanical properties of the TP and SA techniques in repairing PMMRTs. Due to variations in suture types, suturing methods, anchor types, and biomechanical testing protocols across studies, a meta-analysis was not performed. The results showed that SA technique was significantly superior to TP technique in terms of initial load, failure load, contact area, and structural stiffness (P < .05). In addition, in the test of clinical failure load (defined as 3-mm displacement), the SA group (48.6-74.0 N) was significantly higher than TP group (19.9-56.7 N) (P < .001). In terms of displacement characteristics, although 3 studies found no significant difference between the two techniques in terms of initial and failure displacements, the cyclic loading tests of 5 studies all showed that the displacement of the SA group was smaller (P < .01). The contact mechanics analysis showed that the two techniques performed comparably in terms of contact pressure (2 out of 3 studies) and peak pressure, but 2 studies found that the contact area of the SA group was larger (P < .05). The failure mode analysis showed that suture cutout of the meniscus was the most common of the known failure modes for both techniques: 56% in the TP group and 52% in the SA group. In the TP group, the remaining known failures were suture-related (44%, including elongation and breakage). In the SA group, additional known failure modes included suture elongation (19%) and suture eyelet breakage (7%); 22% of failures were uncategorized due to unspecified causes in the original studies. CONCLUSIONS: Compared with TP technique, the PMMRTs repaired by SA technique has better biomechanical properties in terms of displacement during cyclic loading, initial repair load, ultimate failure load, initial stiffness, stiffness in cyclic loading tests, ultimate stiffness and contact area. Suture cutout from the meniscus is the most common cause of failure in both techniques. CLINICAL RELEVANCE: This review confirms from a biomechanical perspective that the SA technique is superior to the TP technique in posterior medial meniscal root repair, and it also provides a basis for selecting surgical methods in the treatment of PMMRTs.