Objective To explore the effect of minimally invasive and mini-incision surgery (MIS) in total hip arthroplasty (THA) on late osteonecrosis of femoral head (ONFH). Methods From March 2003, Eighteen patients (22 hips) with ONFH underwent MIS in THA. Their ages ranged from 24to 57 years, including 13 males and 5 females. The mean body mass index ranged from 17.1 to 30.1(24.6 on average). The Harris hip score was 46 points before operation. Modified posterior-lateral approach was adopted, and the MIS THA was performed by cementless prosthesis. As a comparison, 18 patients (22 hips) were performed by conventional THA at the same period. The data, including bleeding volume during operation, incision length, operative time, and postoperative function recovery, were compared. Results Follow-ups were done for 6 to 20 months (11 months on average). Dislocation occurred in one patient that underwent conventional THA 2 days after operation. No complication occurred in MIS THA group. The incision lengths ranged from 8.7 to 10.5 cm (9.3 cm on average) in MIS THA group, being statistically different (Plt;0.01). There was no significant difference in Harris scoring of the function between the two groups both before the operation and after the operation (Pgt;0.05). The operative time was almost the same, but the bleeding volume in MIS THA group was less (Plt;0.05). The function recovery was faster in MIS THA group.Conclusion The MIS THA is an alternative to the treatment of late ONFH. The advantages of MIS THA are fewer trauma, less bleeding volume, and faster recovery. The MIS THA should be performed by surgeons with rich experiences in THA and hospitals with necessary instruments.
ObjectiveTo analyze the clinical outcomes of 3D-printing assisting minimally invasive fixation of calcaneal fractures. MethodsThe study included 12 patients who were diagnosed with calcaneal fractures between October 2014 and May 2015. Using a real-size 3D-printed calcaneus model, the calcaneal locking plate could be preshaped before the operation and used with a minimally invasive approach to achieve rigid plate fixation just as with the lateral approach. Complications and surgery time were recorded and functional results were evaluated using the American Orthopaedic Foot Society ankle-metapedes score (AOFAS). The reduction of fracture was evaluated using the Bohler angle and Gissane angle. ResultsThere was no relevant postoperative complications. All fractures got bone union. The mean postoperative Bohler angle was (29.4±6.1) ° and the mean postoperative Gissane angle was (121.4±12.6) °. The difference in Bohler angle and calcaneal Gissane angle before and after the surgery was significant (P ＜ 0.01) . The mean postoperative AOFAS score was 75.2±5.4, and the fine/excellent rate was 83.3%. ConclusionWe believe this novel technique can be useful for the operative treatment of displaced intra-articular calcaneal fractures.