Objective To compare the clinical effectiveness between the channel-assisted mini-invasion and open Achilles shortening for treatment of the elongated Achilles tendon following previous rupture.Methods The clinical data of 19 patients admitted from Dec. 2013 to Dec. 2015 and met the inclusion criteria were analyzed retrospectively. Eight patients were treated with shortening operation by channel-assisted minimally invasive repair system, while 11 patients received dissection of Krackow Achilles tendon shortening. There was no significant difference between the two groups in gender, age, injury to operation time, preoperative calf circumference and preoperative AOFAS (American Orthopaedic Foot & Ankle Society) score (P>0.05).Results The operation time, incision length and postoperative hospital days were significantly less in min-invasion group than in incision group (P<0.05). After operation, wound healing by first intention was obtained in incision group except 1 case which got infection and healed by treatment 2 weeks later. No sural nerve and vascular injury and lower extremity deep vein thrombosis existed. MRI showed that the Achilles tendon recovered in both groups at the 8th week follow-up. The patients were followed up for 12-17 months in the mini-invasion group and 12-20 months in the incision group. The calf circumference and AOFAS score of both groups were higher in the last follow-up than that in pre-operation (P<0.05), but no significant difference existed between the two groups at the last follow-up (P>0.05).ConclusionChannel-assisted minimally invasive Achilles tendon shortening operation has not only similar effectiveness to the incision shorting operation for the treatment of elongated Achilles tendon following previous rupture, but also has the advantages of shortening operation time and stay in hospital and avoidance of sural nerve injury.

Objective:To explore which configuration schemes of proximal humerus internal locking system (PHILOS) fixation with endosteal augmentation can provide the optimal biomechanical stability for treatment of osteoporotic proximal humeral fractures by means of finite element analysis.Methods:Based on the CT data of the humerus of an old female volunteer (78 years old, with a bone density T-value of -3.0), a three-dimensional finite element model of the humerus was established by digital medical software such as Mimics 19.0, Geomagic Studio 12, and Creo 2.0 ANSYS Workbench2019. Next, a model of unstable proximal humerus fracture was established and subjected respectively to 5 different fixations: simple PHILOS fixation (PHILOS group), PHILOS plus 6-cm fibula fixation with calcar screws (PHILOS-F-C-6 group), PHILOS plus 6-cm fibula fixation without calcar screws (PHILOS-F-6 group), PHILOS plus 9-cm fibula fixation with calcar screws (PHILOS-F-C-9), and PHILOS plus 9-cm fibula fixation without calcar screws (PHILOS-F-9 group). After a stress mode of shoulder joint abduction at 25° was simulated, a compressive load of 200N was applied to the 5 fixation models. The stress distribution and displacement of fracture ends in different fixation models were tested, and the biomechanical stability was compared among the 5 different internal fixations.Results:Under a shoulder joint abduction at 25° and a load of 200 N, the maximum stress and the displacement of the fracture ends in PHILOS-F-C-9 group (38.678 Mpa and 0.012 mm) decreased by 30.08% and 45.45%, respectively, compared with PHILOS-F-C-6 group (55.321 Mpa and 0.022 mm), and decreased by 12.48% and 15.38%, respectively, in PHILOS-F-9 group (77.012 Mpa and 0.033 mm) compared with PHILOS-F-6 group (88.106 Mpa and 0.039 mm). The maximum stress and the displacement of the fracture ends in PHILOS-F-C-6 group decreased by 37.21% and 43.59%, respectively, compared with PHILOS-F-6 group while decreased by 49.83% and 63.63% in PHILOS-F-C-9 group compared with PHILOS-F-9 group, respectively.Conclusion:For treatment of osteoporotic proximal humeral fractures with medial instability, PHILOS fixation with longer fibula endosteal augmentation plus insertion of calcar screws is a more appropriate choice which can reduce the stress of internal fixation and reduce the displacement of the fracture ends.