Department of Orthopaedic Surgery, Hospital for Special Surgery, Weill Medical College of Cornell University, 535 East 70th Street, New York, NY, 10021, USA.
Department of Biostatistics, Hospital for Special Surgery, Weill Medical College of Cornell University, New York, NY, USA.
Int Orthop. 2021 Jan;45(1):139-145. doi: 10.1007/s00264-020-04839-9. Epub 2020 Oct 11.
Adequate soft tissue tension and balance is paramount to achieve favourable outcomes of total knee arthroplasty (TKA). Implant manufacturers offer 1-mm liner increments to fine-tune ligament tension and balance. In this study, we assessed if soft tissue tension changes introduced by minimal changes in liner thicknesses affect early patient reported outcomes.
Eighty-nine patients undergoing 99 primary, elective TKAs by a single surgeon were included. After achieving adequate ligament balance, the first 50 knees received an insert that would allow 2-3 mm of medial and lateral opening (control group), whereas the last 49 received an insert which was 1 mm thicker, resulting in a slight increase in ligament tension (study group). Sensor technology was used to record compartmental loads. Knee Society Score (KSS), KOOS Jr., and ROM were recorded pre-operatively, six weeks, four and 12 months post-operatively. The Forgotten Joint Score (FJS) was administered four and 12 months post-operatively.
No differences were observed in demographic variables, pre-operative outcome scores, and ROM measures between groups. Six weeks post-operatively, there was no statistically significant difference in the outcome variables. Four months post-operatively, statistically significant differences were only observed in KOOS Jr. (79 and 73.6; p = 0.05), and FJS (59.9 and 45.5; p < 0.01); all of which favoured the control group. There was no difference in the outcome variables at 12 months.
Minor changes in soft tissue tension induced by 1-mm changes in liner thickness resulted in clinically meaningful differences favouring the control group four months post-operatively, but in no clinically noticeable differences 12 months post-operatively. It is possible that lower soft tissue tension may lead to transient improvement in patient-reported early outcomes.
充分的软组织张力和平衡对于实现全膝关节置换术（TKA）的良好结果至关重要。植入物制造商提供 1 毫米衬垫增量，以微调韧带张力和平衡。在这项研究中，我们评估了最小衬垫厚度变化引起的软组织张力变化是否会影响早期患者报告的结果。
纳入了由一位外科医生进行的 99 例初次选择性 TKA 的 89 例患者。在获得足够的韧带平衡后，前 50 例膝关节接受了一种可以提供 2-3 毫米内外开口的植入物（对照组），而最后 49 例接受了稍厚 1 毫米的植入物，导致韧带张力略有增加（研究组）。使用传感器技术记录关节间负荷。在术前、术后 6 周、4 个月和 12 个月记录膝关节学会评分（KSS）、KOOS Jr.和 ROM。术后 4 个月和 12 个月时进行遗忘关节评分（FJS）。
两组之间在人口统计学变量、术前结果评分和 ROM 测量方面没有差异。术后 6 周时，两组间的结果变量无统计学差异。术后 4 个月时，仅 KOOS Jr.（79 和 73.6；p=0.05）和 FJS（59.9 和 45.5；p<0.01）存在统计学显著差异，且均有利于对照组。术后 12 个月时，两组的结果变量无差异。
衬垫厚度 1 毫米的变化引起的软组织张力的微小变化导致术后 4 个月时对照组具有临床意义的差异，但术后 12 个月时没有临床显著差异。较低的软组织张力可能导致患者报告的早期结果暂时改善。
