[Comparative study of gap balancing and measured resection technique in patients receiving staged bilateral total...

Objective: To compare the clinical outcomes of staged total knee arthroplasty (TKA) performed on both knees in the same patient using gap balancing (GB) and measured resection (MR) techniques, respectively. Methods: The clinical data of 57 patients undergoing bilateral staged TKA at the Xi'an Jiaotong University Affiliated Honghui Hospital from July 2018 to January 2020 were analyzed. Using the random number table, MR or GB technique was selected when patients underwent primary TKA, and contralateral procedure was done with another technique. The procedures were performed by one chief surgeon, and the same prosthesis was chosen for all the procedures. The two osteotomy techniques for TKA were compared in terms of surgical status, radiographic data, functional recovery and satisfaction rate. Results: Total of 57 patients, including 16 males and 41 females, were included in the study with a mean age of (68.5±4.6) years (59-79 years) at primary TKA. All patients were followed up for (29.6±4.5) months (22-39 months). The interval between the two procedures was (4.7±3.0) months (0.5-12.0 months). Postoperative drainage was less in the GB side when compared with that in the MR side [(93.6±22.2) ml vs (109.9±36.9) ml, P=0.003]. At the 1-month postoperative follow-up, the visual analogue scale (VAS) of pain was lower on the GB side (3.0±0.8) than on the MR side (3.5±1.2), the range of motion (ROM) was higher on the GB side (105.7°±8.2° vs 100.2°±7.5°), the Knee Society Score (KSS) was higher on the GB side (78.5±5.4 vs 74.2±6.3), and the Western Ontario and McMaster University (WOMAC) score was lower on the GB side (35.4±5.5 vs 38.0±6.3), there were significant differences in the up-mentioned indexes between the two groups (all P<0.05). However, the repeated-measures analysis of variance indicated that there was no significant difference in VAS score, ROM, KSS score and WOMAC score between the two techniques (all P>0.05). The satisfactory rate of GB technique was 84.2%(48/57), ant it was 86.0%(49/57) with MR technique (P=0.446). There was also no significant difference between the two techniques in terms of complications (P=0.754). Conclusion: Both the GB and MR technique result in good knee function with similar clinical outcomes in patients receiving TKA in both knees for osteoarthritis without significant deformity.