Tanaka Hideaki, Soejima Osamu, Muraoka Kunihide, Tanaka Yoshitsugu, Yamamoto Takuaki
Department of Orthopaedic Surgery, Fukuoka University Faculty of Medicine, 7-45-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
Department of Orthopaedic Surgery, Fukuoka Sanno Hospital, 3-6-45, Momochihama, Sawara-ku, Fukuoka 814-0001, Japan.
J Orthop Sci. 2023 Jul;28(4):789-794. doi: 10.1016/j.jos.2022.03.010. Epub 2022 Apr 13.
Management of metacarpophalangeal (MCP) hyperextension deformity in thumb carpometacarpal (CMC) joint arthritis is challenging. It remains unclear how the preoperative MCP joint angle affects the outcomes. The present study aimed to clarify the associations between postoperative MCP hyperextension deformity and outcomes, and to determine the preoperative MCP joint angle that can predict poor outcomes.
We investigated the functional outcomes of patients who underwent surgery for CMC arthritis at two institutions from 2016 to 2020. All patients received a modified Thompson technique, ligament reconstruction suspension arthroplasty, and had no additional treatment for MCP hyperextension. The patients were divided into three groups according to their postoperative MCP joint angles: Group A, <10°; Group B, 10°-20°; Group C, >20°. Evaluations included preoperative and postoperative VAS, Quick DASH, range of motion (ROM), grip power, pinch strength, first web space angle, and postoperative trapezial space ratio (TSR).
Overall, 66 eligible patients (72 thumbs) were identified and received follow-up for a mean of 25.2 months. The 72 thumbs were assigned to Group A (n = 38), Group B (n = 16), and Group C (n = 18). Group C had significantly lower preoperative MCP joint angle and postoperative grip power, pinch strength, and TSR compared with the Group A (P < 0.05). However, there were no significant differences in VAS, Quick DASH, ROM, and first web space angle (P > 0.05). The preoperative risk factor for highly residual MCP hyperextension was preoperative MCP joint angle (OR = 1.078; P = 0.001), with a cut-off value of 21.5° (AUC = 0.79; sensitivity = 0.813; specificity = 0.821).
Postoperative MCP hyperextension of >20° after ligament reconstruction with trapeziectomy has adverse effects on functional outcomes. In cases with preoperative MCP joint angle of >21.5°, additional treatment for MCP hyperextension should be considered.
拇指腕掌关节（CMC）关节炎中掌指关节（MCP）过伸畸形的处理具有挑战性。术前MCP关节角度如何影响治疗结果仍不清楚。本研究旨在阐明术后MCP过伸畸形与治疗结果之间的关联，并确定可预测不良结果的术前MCP关节角度。
我们调查了2016年至2020年在两家机构接受CMC关节炎手术患者的功能结果。所有患者均接受改良汤普森技术、韧带重建悬吊关节成形术，且未对MCP过伸进行额外治疗。根据术后MCP关节角度将患者分为三组：A组，<10°；B组，10°-20°；C组，>20°。评估包括术前和术后视觉模拟评分（VAS）、快速DASH评分、活动范围（ROM）、握力、捏力、第一掌骨间隙角度以及术后大多角骨间隙比值（TSR）。
总体而言，共确定66例符合条件的患者（72侧拇指）并进行了平均25.2个月的随访。72侧拇指被分为A组（n = 38）、B组（n = 16）和C组（n = 18）。与A组相比，C组术前MCP关节角度明显更低，术后握力、捏力和TSR也更低（P < 0.05）。然而，VAS、快速DASH评分、ROM和第一掌骨间隙角度方面无显著差异（P > 0.05）。术前MCP关节角度是MCP高度残留过伸的危险因素（比值比[OR] = 1.078；P = 0.001），截断值为21.5°（曲线下面积[AUC] = 0.79；敏感度 = 0.813；特异度 = 0.821）。
大多角骨切除韧带重建术后MCP过伸>20°对功能结果有不利影响。对于术前MCP关节角度>21.5°的病例，应考虑对MCP过伸进行额外治疗。
