This study was aimed to compare the mechanical characteristics under different physiological load conditions with three-dimensional finite element model of rigid fixation and elastic fixation in the lumbar. We observed the stress distribution characteristics of a sample of healthy male volunteer modeling under vertical, flexion and extension torque situation. The outcomes showed that there existed 4-6 times pressure on the connecting rod of rigid fixation compared with the elastic fixations under different loads, and the stress peak and area of force on elastic fixation were much higher than that of the rigid fixations. The elastic fixation has more biomechanical advantages than rigid fixation in promoting interbody lumbar fusion after surgery.
Objective To evaluate the short-term effectiveness of Kirschner wire (K-wire) elastic fixation in the treatment of Doyle type Ⅰ and Ⅱ mallet finger. Methods Between July 2016 and March 2017, 18 patients with Doyle type Ⅰ and Ⅱ mallet finger were treated. There were 12 males and 6 males, with an average age of 45 years (range, 16-61 years). The index finger was involved in 2 cases, the middle finger in 3 cases, the ring finger in 10 cases, and the little finger in 3 cases. The interval from injury to operation ranged from 2 hours to 45 days (median, 5.5 hours). There were 8 patients of closed wound and 10 patients of open wound. Fourteen patients were simply extensor tendon rupture and 4 were extensor tendon rupture complicated with avulsion fracture. The distal interphalangeal joints (DIPJ) of injured fingers were elastically fixed with the K-wire at mild dorsal extend position. The K-wire was removed after 6 weeks, and the functional training started. Results The operation time was 34-53 minutes (mean, 38.9 minutes). Patients were followed up 3-8 months (mean, 5 months). All incisions healed primarily and no K-wire loosening or infection happened during the period of fixation. All mallet fingers were corrected. The range of motion (ROM) in terms of active flexion of injured DIPJ was (75.83±11.15)° at 6 weeks after operation, showing significant difference when compared with the normal DIPJ of contralateral finger [(85.28±6.06)°] (t=3.158, P=0.003). The ROM in terms of active flexion was (82.67±6.78)° in 15 patients who were followed up at 8 months after operation, showing no significant difference when compared with the normal DIPJ of contralateral finger [(86.00±5.73)°] (t=1.454, P=0.157). After the removal of K-wire at 6 weeks, visual analogue scale (VAS) score of active flexion and of passive flexion to maximum angle were 1.78±0.88 and 3.06±1.06, respectively. According to the total active motion criteria, the effectiveness was rated as excellent in 10 cases, good in 5 cases, moderate in 2 cases, and poor in 1 case, and the excellent and good rate was 83.33%. The patients’ satisfaction were accessed by Likert scale, which were 3-5 (mean, 4.2). Conclusion K-wire elastic fixation in the treatment of Doyle typeⅠand Ⅱ mallet finger can repair the extensor effectively, correct the mallet finger deformity, and also be benefit for the flexion-extension function restoration of DIPJ.
ObjectiveTo review the research progress in the diagnosis and treatment of distal tibiofibular syndesmosis injury.MethodsThe recent literature about distal tibiofibular syndesmosis injury was reviewed and analyzed.ResultsDistal tibiofibular syndesmosis injury is commonly seen in ankle joint injury, the anatomical complexities make diagnosis and treatment difficult. Preoperative physical examination, radiologic evaluation, and intraoperative stress-testing are important for the diagnosis. Aggressive treatment is also recommended for these injuries to prevent long-term chronic instability. Internal fixation is the main treatment, including metal screw, degradable screw, elastic fixation, and hybrid techniques. Metal screw fixation is still the current mainstream, but elastic fixation represented by Suture-button is more in line with the physiological characteristics of ankle joint, and the rate of secondary operation is low while the clinical outcome is satisfactory. The application prospect of elastic fixation is worthy of expectation.ConclusionIt’s crucial for patient with ankle fracture to repair the distal tibiofibular syndesmosis injury. How to diagnose the injury more accurately and simply, how to increase the success rate of reduction, and how to reduce the complications of surgery are still worthy for further exploration.
ObjectiveTo investigate the mid-term effect of lateral placement of bone graft on shoulder joint degeneration after modified arthroscopic Latarjet surgery with elastic fixation for recurrent anterior shoulder dislocation with an anterior glenoid bone defect.MethodsAccording to the inclusion and exclusion criteria, 18 patients with recurrent anterior shoulder dislocation and anterior glenoid bone defect who received the modified arthroscopic Latarjet surgery with elastic fixation between January 2015 and November 2016 were enrolled in this study. There were 12 males and 6 females with an average age of 26.2 years (range, 19-37 years). The number of shoulder dislocation ranged from 4 to 30 times (mean, 8.8 times). The disease duration was 8-49 months (mean, 23.8 months). The mean anterior glenoid bone defect was 25.2% of the glenoid surface (range, 20%-29%). The mean preoperative Instability Severity Index Score (ISIS) was 7.6 (range, 7-10). According to Samilson-Prieto classification, the shoulder joint degeneration was rated as grade 0 in 13 cases, grade Ⅰ in 3 cases, and grade Ⅱ in 2 cases. Before and after operation, the visual analogue scale (VAS) score, American Society of Shoulder and Elbow Surgery (ASES) score, Walch-Duplay score, Rowe score, and shoulder mobility were used to evaluate the effectiveness. Imaging examination was performed to observe the shoulder joint degeneration, the position of the bone graft, and the postoperative shaping of the scapular glenoid.ResultsAll patients were followed up 55-62 months, with an average of 59.6 months. There was no neurovascular injuries, infections, fixation-related and bone graft-related complications. No re-dislocation and revision occurred. All patients returned to normal life, 17 of whom returned to sport. The VAS score was significantly decreased and ASES, Walch-Duplay, and Rowe scores were significantly improved at last follow-up (P<0.05). No significant difference was found in range of motion of forward flexion, abduction, lateral rotation at 90° abduction, internal rotation at 90° abduction, or lateral rotation at 0° between pre- and post-operation (P>0.05). Three-dimensional CT showed that the centers of all bone grafts were between 3∶30 and 4∶30 (right shoulder) or between 7∶40 and 8∶20 (left shoulder) and no bone grafts were positioned superiorly or inferiorly in the glenoid En-face view. All bone grafts were positioned lateral to the scapular glenoid with an average distance of 3.5 mm (range, 2.3-4.6 mm) in cross-sectional imaging by CT. Compared with the preoperative Samilson-Prieto classification results, all cases showed no progression of shoulder joint degeneration at 36, 48 months and last follow-up. All bone grafts remodeled to a steady state within 24 months after operation. The bone graft and glenoid finally remodeled analogous to the shape of the intact glenoid in the En-face view and became flush with the glenoid rim, remodeling to a curved shape congruent to the humeral head in cross-sectional imaging by CT. The shape of the remodeled glenoid at last follow-up was not significantly different from that at 24 months after operation.ConclusionThe lateral placement of the bone graft during modified arthroscopic Latarjet surgery with elastic fixation do not accelerate the imaging changes of shoulder joint degeneration.