Objective: To compare the clinical and radiographic results between primary total knee arthroplasty (TKA) via mini-subvastus or conventional approach through a prospective randomized controlled study.
Methods: Ninety-four patients (104 knees) undergoing primary TKA between January 2011 and April 2012 were evaluated and randomly divided into 2 groups. Forty-six patients (52 knees) underwent TKA via conventional approach (conventional approach group), and 48 patients (52 knees) underwent TKA via mini-subvastus approach (mini-subvastus approach group). In these patients, 45 cases (51 knees) in conventional approach group and 45 cases (49 knees) in mini-subvastus approach group were followed up and recruited in the final analysis. There was no significant difference in age, gender, body mass index, sides, osteoarthritis grading, American Knee Society Score (KSS), Hospital for Special Surgery (HSS) score, visual analogue scale (VAS), range of motion (ROM) of knee between 2 groups ( P>0.05). The clinical indexes were recorded and analyzed, including the operation time, length of incision, total blood loss, blood transfusion after operation, hospital stay time, the time of performing straight leg raise, incision condition, VAS score, ROM of knee, HSS score, and KSS score, hip-knee-ankle angle (HKA), femoral anatomic axis and the femoral prosthesis joint angle (femoral angle), tibia anatomic axis and tibial prosthesis joint angle (tibial angle), femoral prosthesis flexion angle (FPFA), and posterior slope angle (PSA) of the tibial plateau.
Results: All patients were followed up. The average follow-up time was 66.4 months (range, 60.0-72.5 months) in conventional approach group and 65.6 months (range, 60.0-71.2 months) in mini-subvastus approach group. Compared with the conventional approach group, the incision of mini-subvastus approach group shortened, the operation time prolonged, and the time when patients started straight leg raise exercises was earlier; showing significant differences between 2 groups ( P<0.05). There was no significant difference in hospital stay time, total blood loss, and numbers of blood transfusion between 2 groups ( P>0.05). The complication rate was 8.2% (4/49) in mini-subvastus approach group and 0 in conventional approach group, showing no significant difference between 2 groups ( P=0.054). At 1 and 3 days, the VAS and the ROM of knee in mini-subvastus approach group were significantly better than those in conventional approach group ( P<0.05); but there was no significant difference in above indexes between 2 groups at 14 day ( P>0.05). There was no significant difference in HSS and KSS scores between 2 groups at the 1, 3, 6, 12 months and 3, 5 years ( P>0.05). X-ray film showed no aseptic loosening in all cases. There was no significant difference in the measured values and incidence of abnormal patient of HKA, femoral angle, tibial angle, FPFA, and PSA at last follow-up between 2 groups ( P>0.05).
Conclusion: TKA via mini-subvastus approach is helpful to the early function recovery of knee, but the long-term effectiveness is consistent with TKA via conventional approach. As the limited exposure, TKA via mini-subvastus spproach may has high risk of operative complications.
目的: 采用前瞻性随机对照研究，比较经股内侧肌下微创入路与传统手术入路行人工全膝关节置换术（total knee arthroplasty，TKA）的疗效。.
方法: 将 2011 年 1 月—2012 年 4 月收治并符合选择标准的 94 例（104 膝）拟行 TKA 的骨关节炎患者纳入研究，随机分为传统入路组（46 例、52 膝）和微创入路组（48 例、52 膝）；其中传统入路组 45 例（51 膝）、微创入路组 45 例（49 膝）获得完整随访，纳入最终分析。两组患者性别、年龄、体质量指数、侧别、骨关节炎分级以及术前髋膝踝角（hip-knee-ankle angle，HKA）、美国特种外科医院评分（HSS）、美国膝关节协会评分（KSS）、疼痛视觉模拟评分（VAS）、膝关节活动度等一般资料比较，差异均无统计学意义（ P>0.05）。比较两组手术时间、切口长度、总失血量、术后输血例数、住院时间、术后开始行直腿抬高锻炼时间及切口愈合情况；术后膝关节主动活动时 VAS 评分以及膝关节活动度，膝关节功能 HSS 及 KSS 评分；X 线片测量的 HKA、股骨解剖轴线与股骨假体关节面夹角（股骨角）、胫骨解剖轴线与胫骨假体关节面夹角（胫骨角）、股骨假体屈曲角、胫骨平台后倾角。.
结果: 两组患者均获随访，传统入路组随访时间 60.0～72.5 个月，平均 66.4 个月；微创入路组为 60.0～71.2 个月，平均 65.6 个月。与传统入路组相比，微创入路组切口明显缩短、手术时间延长、患者开始直腿抬高锻炼时间提前，比较差异有统计学意义（ P<0.05）。两组总失血量以及术后输血例数、住院时间比较，差异均无统计学意义（ P>0.05）。微创入路组并发症发生率为 8.2%（4/49），传统入路组为 0，差异无统计学意义（ P=0.054）。术后 1、3 d，微创入路组 VAS 评分及膝关节活动度明显优于传统入路组（ P<0.05）；14 d 时两组以上指标比较，差异无统计学意义（ P>0.05）。术后 1、3、6、12 个月以及 3、5 年，两组 HSS 评分及 KSS 评分比较，差异均无统计学意义（ P>0.05）。X 线片复查提示，随访期间假体无松动表现。末次随访时，两组 HKA、股骨角、胫骨角、股骨假体屈曲角以及胫骨平台后倾角测量值及其异常发生率比较，差异均无统计学意义（ P>0.05）。.
结论: 经股内侧肌下微创入路行 TKA 有利于膝关节功能早期恢复，但远期疗效与传统手术入路 TKA 一致；同时因显露范围有限增加了手术并发症发生风险。.
Keywords: Total knee arthroplasty; minimally invasive operation; randomized controlled study; surgical approach.