Minimally invasive percutaneous osteosynthesis versus ORIF for Sanders type II and III calcaneal fractures: a prospective, randomized intervention trial

BACKGROUND: This randomized controlled trial compared the clinical outcomes and complications of a novel minimally invasive percutaneous osteosynthesis (MIPO) with those of conventional treatment via an extended L-shaped lateral approach for calcaneal fractures. METHODS: Sixty-four patients with displaced intraarticular calcaneal fractures were enrolled. The patients were randomly allocated to receive either MIPO (29 patients) or open reduction and internal fixation via an extended L-shaped lateral approach (35 patients). The same calcaneal plate (AO Synthes, Oberdorf, Switzerland) was used in both groups. The primary clinical outcomes included operative time, VAS postoperatively, and wound healing complications. Secondary clinical outcomes included time to operation, length of incision, postoperative drainage, length of hospital stay, medical expense, AOFAS score, and SF-36 score. Preoperative and postoperative calcaneal height, width, and length, Bohler’s angle, and Gissane’s angle were compared. RESULTS: The operative time in the MIPO group was 52.5 ± 11.1 min, which was significantly shorter than 82.8 ± 16.2 min in the conventional treatment group (P < 0.001). One week postoperatively, the VAS value was 3.2 ± 1.4 in the MIPO group, which was lower than that in the conventional treatment group, 3.9 ± 1.3 (P = 0.038). In the conventional treatment group, 13 of 35 fractures (37.1%) had wound healing problems, whereas this issue occurred in only 2 of 29 fractures (6.7%) in the MIPO group (P = 0.004). In the MIPO group, deep and superficial infections occurred in none of the cases and 1 of 29 (3.4%) patients, respectively. Length of incision in the MIPO group was shorter than that in the conventional treatment group (4.2 ± 0.6 vs. 10.9 ± 1.5 cm; P < 0.001). Hospital stay was 9.7 ± 2.8 days in the MIPO group and 11.7 ± 2.6 days in the conventional treatment group (P = 0.004). At the last follow-up, the SF-36 scores and AOFAS scores in the two groups were comparable (P > 0.05). The postoperative radiographic data, the Bohler’s angle, Gissane’s angle, and calcaneal height, width, and length in the two groups were comparable (P > 0.05). CONCLUSIONS: Compared with conventional ORIF, the advantages of MIPO are a considerably shortened operating time and hospital stay, decreased postoperative pain, and reduced risk of wound healing complications.