Relaxation of the MCL after an Open-Wedge High Tibial Osteotomy results in decreasing contact pressures of the knee over time

Abstract

PurposeThe objective of this study was to investigate the effect of a medial open-wedge osteotomy (OWO) and the release of the superficial medial collateral ligament (MCL) on the tibiofemoral cartilage pressure, the MCL tension and the valgus laxity of the knee.MethodsSeven fresh-frozen, human cadaveric knees were used. Medial and lateral mean contact pressure (CP), peak contact pressure (peakCP), and contact area (CA) were measured using a pressure-sensitive film (I-Scan; Tekscan, Boston, MA). The MCL tension was measured using a custom-made device. These measurements were continuously recorded for 5 min after an OWO of 10°. After the osteotomy, the valgus laxity was measured with a handheld Newtonmeter. For one knee, the measurements were continued for 24 h. At the end, a complete release of the superficial MCL was performed and the measurements were repeated at 10°.ResultsThere was relaxation of the MCL after the osteotomy; the tension dropped in 5 min with 10.7% (mean difference 20.5 N (95% CI 16.1–24.9)), and in 24 h, the tension decreased by 24.2% (absolute difference 38.8 N) (one knee). After the osteotomy, the mean CP, peakCP and CA increased in the medial compartment (absolute difference 0.17 MPa (95% CI 0.14–0.20), 0.27 MPa (95% CI 0.24–0.30), 132.9mm2 (95% CI 67.7–198.2), respectively), and decreased in the lateral compartment (absolute difference 0.02 MPa (95% CI 0.03 –0.01), 0.08 MPa (95% CI 0.11 – 0.04), 47.0 mm2 (95% CI −105.8 to 11.8), respectively). Only after a release of the superficial MCL, the mean CP, peak CP and CA significantly decreased in the medial compartment (absolute difference 0.17, 0.27 MPa, 119.8 mm2, respectively), and increased in the lateral compartment (absolute difference 0.02, 0.11 MPa, 52.4 mm2, respectively). After the release of the superficial MCL, a mean increase of 7.9° [mean difference − 0.1° (95% CI −1.9 to 1.6)] of the valgus laxity was found.ConclusionsA release of the superficial MCL helps achieve the goal of reducing medial cartilage pressure in an OWO. There was considerable relaxation of the MCL after an OWO that resulted in a decrease of the mean CP in the medial and lateral compartments of the knee over time. However, cartilage pressure shifted from the medial to the lateral compartment only after release of the superficial MCL. The release of the superficial MCL caused a significant increase in the valgus laxity, which could influence stability after an OWO.Level of evidenceI.

Superficial Medial Collateral Ligament Reattachment During High Tibial Osteotomy: Regulate Tension, Preserve Stability!

“…Studies seem to confirm these presumptions. Van Egmond et al 10 . reported in their cadaveric study that after releasing the sMCL, the mean contact pressure, peak contact pressure, and contact area decreased in the medial compartment.…”

“…Although the effectiveness of the HTO seems to be clear, there are still some debates on the technical details of this procedure to obtain better outcomes 9, 10, 11. It is clear that during HTO, release of the sMCL should be performed because omitting it might not allow for proper osteotomy gap opening and may result in overstress on the medial compartment.…”

“…It is well-known that the sMCL is a primary restraint on valgus stress. Some authors have suggested that release of the sMCL without its further reattachment is possible and that this does not affect patient-reported outcomes 9, 10. Either way, its release, which is inevitable during HTO, may lead to medial instability when it is not addressed after osteotomy.…”

A Systematic Review on Selected Complications of Open-Wedge High Tibial Osteotomy from Clinical and Biomechanical Perspectives

“…As shown in Table 1 , various studies showed that performing an OWHTO without any release of the sMCL results in an increase of the sMCL strain, an increase in the contact area and pressures on the medial tibiofemoral compartment, and a decrease in these parameters on the lateral compartment [ 18 , 27 , 28 ]. This condition, which is in contrast with the objective of performing OWHTO, can even be deteriorated by increasing the size of the opened wedge.…”

The role of biomaterials in the treatment of meniscal tears

“…Surgical treatment of meniscal injuries has undergone a number of developments over the past two decades, moving from open arthroscopic surgery; from total to partial meniscectomy and adding novel treatments; such as repair using a variety of devices, materials, transplants, collagen implants or xenografts ( Kim et al, 2013 ; Jiang et al, 2012 ; Grogan et al, 2017 ; Baek et al, 2017 ). If meniscectomy takes place or insisted upon, this procedure is mainly due to changes in load distribution across the articular cartilage as studies have shown that following total meniscectomy peak contact pressures increase by 253% and 165% following partial meniscectomy ( Lee et al, 2006 ; Baratz, Fu & Mengato, 1986 ; Beamer et al, 2017 ; Van Egmond et al, 2017 ). Following meniscectomy, there is also evidence of reduced muscle strength, altered gait patterns and clinical outcomes ( Hall et al, 2013 ; Hall et al, 2014 ; McLeod et al, 2012 ; Sturnieks et al, 2008a ; Sturnieks, Besier & Lloyd, 2011 ; Sturnieks et al, 2008b ; Salata, Gibbs & Sekiya, 2010 ; Scholes et al, 2017 ).…”