Simulated operation combines patient-specific guide technology is superior to conventional technology for supramalleolar osteotomy: a retrospective comparative study

Abstract Background: Over the past seven years, our team has designed a simulated operation combines patient-specific guide (SO-PSI) assisted supramalleolar osteotomy (SMOT) method and applied it to the clinic. This study aimed to determine the difference between SO-PSI technology and conventional operation (CO) technology for SMOT in preoperative planning, intraoperative application and postoperative curative effect. Methods: We retrospectively analyzed the data of SMOT in our hospital between October 2014 and December 2018; 28 patients were enrolled and divided into CO group (n=17) and SO-PSI group (n=11); the mean follow-up time was 33.4 (range, 13 to 59) months. We analyzed and compared perioperative data, accuracy of preoperative planning and intraoperative application, difference between pre- and post-operative of radiologic ankle angles, and change of AOFAS score, VAS, range of motion of ankle and Takakura stage after operation. Then we performed statistical analyses. Results: All ankle alignments and positions of two groups have been recovered. Compared with CO group, SO-PSI group has a shorter operative time and a postoperative hospital stay, a decreased number of fluoroscopies and a reduction of albumin, a longer preoperative planning time and a preoperative hospital stay and an increased hospitalization expenses. In SO-PSI group, the ankle angles between preoperative planning and postoperative shown good correlation, but not in CO group; the mean tibial ankle center discrepancy of SO-PSI group was 1.86±1.06 mm. After follow-up, all radiologic parameters of two groups significantly improved, but the improvement of tibial anterior surface angle and tibiotalar tilt angle of SO-PSI group were more obvious than that of CO group; AOFAS score, VAS, range of motion of ankle and Takakura stage of two groups improved after operation; but overall the improvements of SO-PSI group were better than the CO group. Conclusions: SO-PSI technology can carry out the preoperative plan accurately and quickly in SMOT; In general, compared with the conventional technology, SO-PSI technology has advantages in preoperative planning, intraoperative application and postoperative curative effect. Keywords: Supramalleolar osteotomy; Simulated operation; Patient-specific guide; Accuracy of preoperative planning; Practicability of application