Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
Corin Group USA, Tampa, Florida, USA.
Bone Joint J. 2021 Jun;103-B(6 Supple A):67-73. doi: 10.1302/0301-620X.103B6.BJJ-2020-2305.R1.
Neither a surgeon's intraoperative impression nor the parameters of computer navigation have been shown to be predictive of the outcomes following total knee arthroplasty (TKA). The aim of this study was to determine whether a surgeon, with robotic assistance, can predict the outcome as assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) for pain (KPS), one year postoperatively, and establish what factors correlate with poor KOOS scores in a well-aligned and balanced TKA.
A total of 134 consecutive patients who underwent TKA using a dynamic ligament tensioning robotic system with a tibia first resection technique and a cruciate sacrificing ultracongruent TKA system were enrolled into a prospective study. Each TKA was graded based on the final mediolateral ligament balance at 10° and 90° of flexion: 1) < 1 mm difference in the thickness of the tibial insert and that which was planned (n = 75); 2) < 1 mm difference (n = 26); 3) between 1 mm to 2 mm difference (n = 26); and 4) > 2 mm difference (n = 7). The mean one-year KPS score for each grade of TKA was compared and the likelihood of achieving an KPS score of > 90 was calculated. Finally, the factors associated with lower KPS despite achieving a high-grade TKA (grade A and B) were analyzed.
Patients with a grade of A or B TKA had significantly higher mean one-year KPS scores compared with those with C or D grades (p = 0.031). There was no difference in KPS scores in grade A or B TKAs, but 33% of these patients did not have a KPS score of > 90. While there was no correlation with age, sex, preoperative deformity, and preoperative KOOS and Patient-Reported Outcomes Measurement Information System (PROMIS) physical scores, patients with a KPS score of < 90, despite a grade A or B TKA, had lower PROMIS mental health scores compared with those with KPS scores of > 90 (54.1 vs 50.8; p = 0.043). Patients with grade A and B TKAs with KPS > 90 were significantly more likely to respond with "my expectations were too low", and with "the knee is performing better than expected" compared with patients with these grades of TKA who had a KPS score of < 90 (40% vs 22%; p = 0.004).
A TKA balanced with robotic assistance to within 1 mm of difference between the medial and lateral sides in both flexion and extension had a higher KPS score one year postoperatively. Despite accurate ligament balance information, a robotic system could not guarantee excellent pain relief. Patient expectations and mental status also significantly affected the perceived success of TKA. Cite this article: 2021;103-B(6 Supple A):67-73.
术中医生的印象或计算机导航的参数均不能预测全膝关节置换术（TKA）后的结果。本研究的目的是确定是否可以通过机器人辅助来预测术后一年的膝关节损伤和骨关节炎结果评分（KOOS）的疼痛（KPS），并确定在对线和平衡良好的 TKA 中哪些因素与较差的 KOOS 评分相关。
共纳入 134 例连续接受采用动态韧带张力机器人系统进行的 TKA 的患者，该系统采用胫骨初次切除技术和牺牲十字韧带的超匹配 TKA 系统。每个 TKA 根据 10°和 90°屈曲时内外侧间室韧带平衡的最终结果进行分级：1）胫骨插入物的厚度与计划厚度相差<1mm（n=75）；2）相差<1mm（n=26）；3）相差 1mm 至 2mm（n=26）；4）相差>2mm（n=7）。比较每个 TKA 分级的平均一年 KPS 评分，并计算达到 KPS 评分>90 的可能性。最后，分析了尽管达到高分级 TKA（A 级和 B 级）但仍存在较低 KPS 评分的相关因素。
A 级或 B 级 TKA 的患者的平均一年 KPS 评分明显高于 C 级或 D 级（p=0.031）。A 级或 B 级 TKA 之间的 KPS 评分没有差异，但其中 33%的患者的 KPS 评分<90。尽管与年龄、性别、术前畸形、术前 KOOS 和患者报告的结果测量信息系统（PROMIS）身体评分无相关性，但 KPS 评分<90 的患者的 PROMIS 心理健康评分明显低于 KPS 评分>90 的患者（54.1 对 50.8；p=0.043）。尽管达到 A 级或 B 级 TKA，但 KPS 评分>90 的患者中，“我的期望太低”和“膝关节的表现超出预期”的可能性显著高于 KPS 评分<90 的患者（40%对 22%；p=0.004）。
在膝关节的内外侧在屈曲和伸展时都使用机器人辅助达到 1mm 以内的差异平衡的 TKA 术后一年的 KPS 评分更高。尽管有准确的韧带平衡信息，但机器人系统并不能保证优异的疼痛缓解。患者的期望和心理状态也显著影响 TKA 的整体感知效果。
