Objective To review the biomechanics of internal fixators for proximal humeral fractures, and to compare the mechanical stabil ity of various internal fixators. Methods The l iterature concerning the biomechanics of internal fixators for proximal humeral fractures was extensively analyzed. Results The most important things for best shoulder functional results are optimal anatomical reduction and stable fixation. At present, there are a lot of methods to treat proximal humeral fractures. Locking-plate exhibites significant mechanical stabil ity and has many advantages over other internal fixators by biomechanical comparison. Conclusion Locking-plate has better fixation stabil ity than other internal fixators and is the first choice to treat proximal humeral fractures.
Objective To evaluate the effectiveness of locking plates for Neer 3- and 4-part proximal humerus fractures. Methods A retrospective analysis was made on the clinical data of 77 patients with 3- or 4-part proximal humerus fractures, who underwent open reduction and internal fixation of locking plates and were followed up more than 12 months between July 2008 and May 2011. There were 39 males and 38 females with an average age of 54.2 years (range, 18-81 years). Fractures were caused by falling in 47 cases, by traffic accident in 16 cases, by falling from height in 4 cases, by sporting in 5 cases, and by other reasons in 5 cases. The time between injury and operation was 2-16 days (mean, 4.5 days). According to Neer classification, there were 54 cases of 3-part fracture and 23 cases of 4-part fracture. The Constant scores, visual analogue score (VAS), and the complications were evaluated during follow-up. Results After operation, healing of incisions by first intention was obtained in 76 cases and healing by second intention in 1 case. All patients were followed up 12-36 months (mean, 18.5 months). At last follow-up, the Constant score was 71.1 ± 11.9; the results were excellent in 18 cases, good in 24 cases, fair in 25 cases, and poor in 10 cases with an excellent and good rate of 54.5%. The VAS score was 2.8 ± 2.2. Bone nonunion occurred in 2 cases; the other patients had bone union within 2-6 months (mean, 3.2 months). The complications occurred in 25 cases (32.5%). Revision surgery was performed in 15 patients (19.5%). Conclusion The treatment of Neer 3- and 4-part proximal humerus fractures remains challenging. Anatomic reduction, stable fixation, and reduced humeral head blood supply disruption may lead to a satisfactory outcome.
Objective To summarize the surgical learning curve and preliminary operative experience of dual-robotic navigated minimally invasive treatment on pelvic fractures by TiRobot and Artis Zeego. Methods Between July 2019 and February 2021, 90 patients with pelvic fractures were treated with dual-robotic navigated minimally invasive surgery by TiRobot and Artis Zeego. There were 64 males and 26 females, with an average age of 46.5 years (range, 13-78 years). Body mass index was 14.67-32.66 kg/m2 (mean, 23.61 kg/m2). Causes of injuries included traffic accident in 43 cases, falling from height in 37 cases, low-energy injuries such as flat falls in 10 cases. The interval between injury and surgery was 1-36 days (mean, 7.3 days). According to the location of the implanted screws, the patients were divided into sacroiliac screw group (n=33), acetabular screw group (acetabulum anterior/posterior column, n=24), composite screws group (sacroiliac and acetabulum anterior/posterior column, n=33). According to the screw implantation time and accuracy, the surgical learning curve was plotted, and the differences in the relevant indicators between learning stage and skilled stage were compared. Results All 90 patients successfully completed the operation, the intraoperative bleeding volume was 5-200 mL (median, 20 mL). There was no vascular or nerve injury. All incisions healed by first intention. The screw implantation time ranged from 7.5 to 33.0 minutes (mean, 18.92 minutes), and the screw implantation accuracy ranged from 1.1 to 1.8 mm (mean, 1.56 mm). According to the learning curve, the practice stage of 3 groups was reached after 7, 10, and 11 cases, respectively. With the accumulation of surgical experience, the screw implantation time had a significant downward trend. Compared with the learning stage, the screw implantation time on skilled stage in 3 groups significantly shortened (P<0.05), but the difference in the screw implantation accuracy was not significant (P>0.05). Conclusion TiRobot and Artis Zeego assisted pelvic fracture surgery is safe and efficient, which helps the surgeon to quickly master the pelvic channel screw surgery, and the operation time is significantly shortened on the premise of ensuring the implantation accuracy.