Seil, Romain

Abstract Medial meniscus extrusion, particularly in the setting of medial meniscus posterior root tears (MMPRTs), has become an area of interest in recent years due to the correlation between meniscus extrusion with inferior clinical outcomes, progression to osteoarthritis, and increased rate of conversion to total knee arthroplasty after MMPRT repair. This correlation led to the development of meniscus centralisations procedures that can be performed in addition to MMPRT repair and/or high tibial osteotomy. Although it was originally thought that medial meniscus extrusion was a consequence of MMPRTs, it has been reported that meniscus extrusion often precedes the development of MMPRTs, which suggests that there may be underlying meniscus pathology that predisposes to the development of both meniscus extrusion and MMPRTs. The purpose of this narrative review is to provide an overview of the anatomy, pathology, and surgical management of meniscus extrusion and MMPRTs, while identifying areas of future research to further elucidate the relationship meniscus extrusion and MMPRTs that may be necessary to improve outcomes after MMPRT repair. Level of Evidence Level V.

Background: Optimized surgical fixation and meniscal stabilization during rehabilitation increase healing success. However, the latest generation of all-inside devices has not yet been biomechanically compared with inside-out suture tape (IO-ST) repair. Hypothesis: (1) The contact area of a suture anchor (SA) would compensate for a meniscal defect better than polyether ether ketone anchors (PA); (2) adjustable tensioning for all-inside meniscal repair fixation would result in higher initial load than IO-ST repair; and (3) stiffer constructs would decrease secondary displacement. Study Design: Controlled laboratory study. Methods: This study investigates human menisci (N = 39) via microscopic imaging and a biomechanical testing protocol. For the imaging protocol, needles of an all-inside SA or PA device and an IO-ST device were inserted after staining to measure the iatrogenic defect created by the needle insertion (n = 20) and the length, width, and meniscus contact area of deployed all-inside anchors (n = 6). For biomechanical testing, menisci with longitudinal bucket handle tears were prepared, and single stitches were repaired (each n = 9). After suture tensioning (50 N) and fixation, initial load, initial stiffness, and relief displacement were measured. Constructs underwent cyclic loading between 2 and 20 N, with 10,000 cycles (0.75 Hz), and stiffness and displacement were measured. Ultimate stiffness and load-to-failure were analyzed at 3.15 mm/sec. Results: All-inside needles created greater iatrogenic meniscal defects ( P < .001) than IO-ST repair. While PAs were longer ( P < .001), SAs were wider with a greater meniscal contact area (both P < .001). IO-ST repair resulted in the lowest initial load ( P < .001) and relief displacement ( P < .001), whereas SA repair resulted in a higher initial load ( P < .007) and stiffness ( P < .023) than PA repair. The overall stiffer SA fixation ( P < 001) significantly reduced cyclic displacement compared with other repairs ( P < .044). The PA group failed due to an anchor fracture at a significantly lower load (84.3 ± 10.7 N; P < .001) than the IO-ST (136.4 ± 10.5 N) and the SA repair (122.1 ± 17.5 N), with a suture-based failure mode. The ultimate stiffness of SA constructs was higher ( P < .045) than that of other repairs. Conclusion: While all-inside devices showed improved primary stability, the IO-ST construct demonstrated the highest load-to-failure. In a human cadaveric model, meniscal repair with a more compact and conforming SA was stiffer and reduced cyclic displacement compared with PA and IO-ST repair. Clinical Relevance: All-inside SA repair improved primary stability. Future clinical series will define the overall significance of healing rates.

Multiligament knee injuries (MLKIs) represent a broad spectrum of pathology with potentially devastating consequences. Currently, disagreement in the terminology, diagnosis and treatment of these injuries limits clinical care and research. This study aimed to develop consensus on the nomenclature, diagnosis, treatment and rehabilitation strategies for patients with MLKI, while identifying important research priorities for further study. An international consensus process was conducted using validated Delphi methodology in line with British Journal of Sports Medicine guidelines. A multidisciplinary panel of 39 members from 14 countries, completed 3 rounds of online surveys exploring aspects of nomenclature, diagnosis, treatment, rehabilitation and future research priorities. Levels of agreement (LoA) with each statement were rated anonymously on a 5-point Likert scale, with experts encouraged to suggest modifications or additional statements. LoA for consensus in the final round were defined ‘a priori’ if >75% of respondents agreed and fewer than 10% disagreed, and dissenting viewpoints were recorded and discussed. After three Delphi rounds, 50 items (92.6%) reached consensus. Key statements that reached consensus within nomenclature included a clear definition for MLKI (LoA 97.4%) and the need for an updated MLKI classification system that classifies injury mechanism, extent of non-ligamentous structures injured and the presence or absence of dislocation. Within diagnosis, consensus was reached that there should be a low threshold for assessment with CT angiography for MLKI within a high-energy context and for certain injury patterns including bicruciate and PLC injuries (LoA 89.7%). The value of stress radiography or intraoperative fluoroscopy also reached consensus (LoA 89.7%). Within treatment, it was generally agreed that existing literature generally favours operative management of MLKI, particularly for young patients (LoA 100%), and that single-stage surgery should be performed whenever possible (LoA 92.3%). This consensus statement will facilitate clinical communication in MLKI, the care of these patients and future research within MLKI.