Effect of Lower Limb Alignment in Medial Meniscus–Deficient Knees on Tibiofemoral Contact Pressure

Abstract

Background:Degenerative medial meniscal tears and subsequent partial meniscal resection compromise meniscal function and lead to an overload of the medial compartment. In addition, lower limb alignment plays a key role in load distribution between the medial and lateral knee compartments, and varus alignment is a potential risk factor for medial osteoarthritis.Purpose/Hypothesis:The purpose of this biomechanical study was to investigate the effect of valgus and varus alignment on peak pressure and contact area in knees with concomitant horizontal medial meniscal tears and subsequent leaflet resection. It was hypothesized that varus alignment in combination with meniscal loss leads to the highest peak pressure within the medial compartment.Study Design:Controlled laboratory study.Methods:Six fresh-frozen human cadaveric knees were axially loaded using a 1000-N compressive load in full extension with the mechanical axis rotated to intersect the tibial plateau at 40%, 45%, 50%, 55%, and 60% of its width (TPW) to simulate varus and valgus alignment. Tibiofemoral peak contact pressure and contact area of the medial and lateral compartments were determined using pressure-sensitive foils in each of 4 different meniscal conditions: intact, 15-mm horizontal tear of the posterior horn, inferior leaflet resection, and resection of both leaflets.Results:The effect of alignment on peak pressure (normalized to the neutral axis) within the medial compartment in cases of an intact meniscus was measured as follows: varus shift resulted in a mean increase in peak pressure of 18.5% at 45% of the TPW and 37.4% at 40% of the TPW, whereas valgus shift led to a mean decrease in peak pressure of 8.7% at 55% of the TPW and 23.1% at 60% of the TPW. Peak pressure changes between the intact meniscus and resection within the medial compartment was less in valgus-aligned knees (0.21 MPa at 60% TPW, 0.59 MPa at 50% TPW, and 0.76 MPa at 40% TPW). Contact area was significantly reduced after partial meniscal resection in the neutral axis (intact, 553.5 ± 87.6 mm2; resection of both leaflets, 323.3 ± 84.2 mm2; P < .001). This finding was consistent in any alignment.Conclusion:Both partial medial meniscal resection and varus alignment led to an increase in medial compartment peak pressure. Valgus alignment prevented medial overloading by decreasing contact pressure even after partial meniscal resection. A horizontal meniscal tear did not influence peak pressure and contact area even in varus alignment.Clinical Relevance:As a clinical consequence, partial meniscal resection should be avoided to maintain the original biomechanical behavior, and the mechanical axis should be taken into account if partial meniscectomy is necessary.

Arthroscopic all-inside repair with suture hook for horizontal tear of the lateral meniscus at the popliteal hiatus region: a preliminary report

“…Without such a distance of the meniscus fixation from the coronary ligament and the knee joint capsule, the remaining superior or inferior leaf is not stable, especially when the tear extends anterior to posterior. On the other hand, a total or partial meniscectomy may result in negative outcomes, including joint alignment, contact pressure, and degenerative changes, which should be avoided [1,5,14].…”

“…According to a research, regardless of whether inferior leaflet or both leaflet resection was performed for the horizontal medial meniscal tears, femorotibial contact pressure increased and contact area decreased significantly. The peak pressure of the medial compartment in neutral alignment status is 1.95 ± 0.57 Mpa with intact menscus, which can be increased to 2.45 ± 0.87Mpa with single-leaflet resection and 2.54 ± 0.76 Mpa with double-leaflet resection respectively [5]. Meniscus repair is another treatment option and can preserve more meniscus tissue.…”

The effect of a centralization procedure for extruded lateral meniscus on load distribution in porcine knee joints at different flexion angles

“…It is caused by the disruption of the meniscus hoop function and is often observed after meniscectomy [1,4], meniscus root tears [5], and with aging [6][7][8]. Meniscal extrusion initiates osteoarthritis (OA) and accompanies its progression [9][10][11]. Restoring the lost function caused by meniscus extrusion can delay OA progression [12].…”

A Modified Arthroscopic All-inside Repair for Lateral Meniscal Tears Anterior to the Popliteal Hiatus: A Retrospective Case Series with Minimum 2-Year Follow-Up

“…Currently, the surgical methods for meniscal tears mainly include meniscectomy and meniscal repair. As multiple studies have shown that meniscectomy would lead to decreased tibiofemoral joint contact area, increased cartilage stress load, and accelerate degenerative joint changes [14][15][16]. Therefore, meniscal repair should be considered a priority in managing meniscal tears, especially for young patients.…”