# A novel meniscal root refixation pull‐in technique with an all‐suture anchor shows biomechanical properties comparable to standard suture anchor and transtibial pull‐out techniques

## TL;DR

A new technique for repairing meniscal root tears using a pulled-in suture anchor shows similar strength to traditional methods, but none fully restore the original meniscal root's stability.

## Contribution

A novel pull-in technique using an all-suture anchor is introduced and biomechanically compared to standard meniscal root repair methods.

## Key findings

- No repair technique restored the biomechanical properties of the native meniscal root.
- The pull-in technique showed comparable load-to-failure and stiffness to conventional methods.
- The push-in technique had significantly higher displacement after cyclic loading compared to the native meniscal root.

## Abstract

Repair techniques for posterior meniscal root (PMMR) tears include repair with transtibial pull‐out and anchors. An alternative approach uses all‐suture anchors pulled in, avoiding a posterior medial portal. While clinical feasibility has been assessed, biomechanical properties of this technique remain unknown. We hypothesised that the biomechanical properties using the pull‐in technique would be comparable to those achieved with conventional repair techniques.

Fifty fresh‐frozen porcine tibiae were fixed in a steel pot. Whereas in group (1) the native meniscal root was kept intact (native meniscal root (NM)), the PMMR was sectioned and refixed in groups (2)–(5): (2) Double‐loaded suture anchor (screw anchor) (SA), (3) transtibial pull‐out repair with two sutures (TTPO), (4) double‐loaded pull‐in repair with all‐suture anchor that was pulled into the subcortical bone which was predrilled from retrograde direction (PULL) and (5) double‐loaded push‐in repair with all‐suture anchor traditionally pushed into the predrilled subcortical bone in antegrade direction (PUSH). Testing was performed using a universal testing machine with 1000 cycles (5–20 N/0.5 Hz) with subsequent load‐to‐failure (LTF) meaning failure of the NM or refixation. Outcomes measured included LTF (N), cyclic displacement (mm), and stiffness (N/mm). The failure mode was documented macroscopically.

Controlled laboratory study.

No repair technique restored the stability of the NM, reaching 1064.6 ± 226.0 N in LTF (p ≤ 0.0001). Reconstructions had significantly lower LTF: SA (251.4 ± 52.8 N), TTPO (233.4 ± 50.0 N), PULL (206.2 ± 86.5 N) and PUSH (214.3 ± 55.2 N). The NM showed the highest stiffness with 156.1 ± 76.3 N/mm (p ≤ .0001) compared to (SA) 36.2 ± 10.1 N/mm, (TTPO) 33.6 ± 6.2 N/mm, (PULL) 36.8 ± 12.7 N/mm, (PUSH) 27.7 ± 6.6 N/mm. Increased displacement after 1000 cycles was shown, with (2.3 ± 0.7 mm) in PULL, only with significant differences noted between NM (1.5 ± 0.8 mm) and PUSH (3.1 ± 0.7 mm) (p ≤ .001), NM and SA (2.5 ± 0.8 mm) (p ≤ .05), and TTPO (2.1 ± 0.7 mm) and PUSH (p ≤ .05). No failures occurred during cyclic loading. Failure after LTF was always a suture cut‐out at the meniscus.

Current repair techniques for posterior medial root tears do not fully restore the biomechanical properties of an intact root. The new pull‐in technique with an all‐suture anchor which is pulled in instead of pushed in shows biomechanical properties comparable to conventional methods, especially regarding LTF.

There is no level of evidence as this study was an experimental laboratory study.