Department of Orthopaedic Surgery, Kobe University Graduate School of Medicine, 7-5-1, Kusunoki-cho, Chuo-ku, Kobe, Hyogo, 650-0017, Japan.
Department of Orthopaedic Surgery, Kobe Kaisei Hospital, Kobe, Hyogo, Japan.
Knee Surg Sports Traumatol Arthrosc. 2018 Jun;26(6):1737-1742. doi: 10.1007/s00167-017-4763-8. Epub 2017 Nov 9.
The purpose of this study was to examine the relationship between medial tibial joint line elevation and the improvement of range of motion (ROM) in unicompartmental knee arthroplasty (UKA). The hypothesis was that limited elevation of tibial joint line will improve knee range of motion in UKA.
Forty-six consecutive medial UKAs were enrolled in this study. Medial tibial joint line elevation was defined as the polyethylene insert and tibial tray thickness minus the tibial osteotomy and sawblade thickness. Positive values indicated an elevation of the tibial joint line. A component gap between the femoral trial prosthesis and the medial tibial osteotomy surface was also examined. Joint loosening was also calculated based on the joint component gap minus insert and tibial tray thickness. The correlation of the medial tibial joint line elevation with joint looseness and postoperative range of motion were analyzed.
The mean medial tibial joint line elevation was 4.9 ± 1.1 mm. The medial tibial joint line elevation reduced the improvement of knee extension (R = - 0.43, p < 0.01). The medial tibial joint line elevation was also correlated with reduced loosening of the joint knee extension (R = - 0.42, p < 0.01). This, in turn, resulted in limited improvement of the knee extension angle. Moreover, joint line elevation under 5 mm significantly improved knee extension angle compared to joint line elevation over 5 mm.
The medial joint line elevation of the tibia in UKA reduced the improvement of knee extension angle, due to a reduced joint looseness at knee extension. A tibial joint line elevation greater than 5 mm in UKA should be avoided to prevent postoperative flexion contracture. For the clinical relevance, this study clarified that the medial joint line of the tibia is an important factor to prevent postoperative flexion contracture in UKA.
II.
本研究旨在探讨内侧胫骨关节线抬高与单髁膝关节置换术（UKA）中关节活动度（ROM）改善之间的关系。假设是有限的胫骨关节线抬高将改善 UKA 中的膝关节活动度。
本研究纳入了 46 例连续的内侧 UKA。内侧胫骨关节线抬高定义为聚乙烯衬垫和胫骨托厚度减去胫骨截骨和锯片厚度。正值表示胫骨关节线抬高。还检查了股骨试模和内侧胫骨截骨面之间的关节间隙。根据关节组件间隙减去插入物和胫骨托厚度，还计算了关节松动。分析了内侧胫骨关节线抬高与关节松动和术后关节活动度的相关性。
内侧胫骨关节线抬高的平均高度为 4.9±1.1mm。内侧胫骨关节线抬高减少了膝关节伸展的改善（R=-0.43，p<0.01）。内侧胫骨关节线抬高也与膝关节伸展的关节松动减少相关（R=-0.42，p<0.01）。这反过来又导致膝关节伸展角度的改善有限。此外，与关节线抬高超过 5mm 相比，关节线抬高低于 5mm 显著改善了膝关节伸展角度。
UKA 中胫骨内侧关节线抬高减少了膝关节伸展角度的改善，这是由于膝关节伸展时关节松动减少所致。UKA 中胫骨关节线抬高大于 5mm 应避免，以防止术后屈曲挛缩。就临床相关性而言，本研究阐明了胫骨内侧关节线是预防 UKA 术后屈曲挛缩的重要因素。
II 级。
