Predicting failure after surgical fixation of proximal humerus fractures.

BACKGROUND: Several studies reported high failures rates after internal fixation of proximal humerus fractures. Loss of reduction and screw cut-out are the most common reasons for revision surgery. Several risk factors for failure have been described in the literature. The aim of the present study was to assess risk factors for failure after surgical fixation of unstable proximal humerus fractures in a multivariate setup. METHODS: Two different surgical techniques (PHILOS locking plate and Humerusblock) were used. In the PHILOS group, every kind of postoperative relative movement between the implant and the humeral head or shaft was defined as failure. In the Humerusblock group, postoperative movement between the humeral head and the shaft in terms of angulation or translational displacement was defined as failure. The following parameters were assessed: age, gender, cancellous bone mineral density (BMD) of the humeral head, fracture type, medial metaphyseal comminution, medial metaphyseal head extension, initial angulation of the humeral head in the frontal plane, initial anteversion of the humeral head, medial hinge displacement, maximum displacement of the tuberosities with respect to the head, surgical technique, anatomic reconstruction and restoration of the medial cortical support. RESULTS: The following parameters were found to have a significant influence on the failure rate: age, local BMD, anatomic reduction, and restoration of the medial cortical support. The failure rate significantly increased with the number of risk factors. CONCLUSION: Preoperative assessment of the local BMD and the patients' biological age as well as intraoperative anatomic reduction and restoration of the medial cortical support are the essentials for successful surgical fixation of proximal humerus fractures. Multifragmentary fracture patterns in old patients with low local BMD are prone for fixation failure. If the surgeon is not able to achieve anatomic reduction and restoration of the medial cortical support intraoperatively in this situation, adjustments such as augmentation or primary arthroplasty should be considered.

Elastic stable intramedullary nailing versus nonoperative treatment of displaced midshaft clavicular fractures-a randomized, controlled, clinical trial.

OBJECTIVE: To compare elastic stable intramedullary nailing (ESIN) with nonoperative treatment of fully displaced midshaft clavicular fractures in adults. DESIGN: The study was a randomized, controlled, clinical trial. SETTING: Level 1 trauma center. PATIENTS AND METHODS: Sixty patients between 18 and 65 years of age participated and completed the study. They were randomized to either operative or nonoperative treatment with a 2-year follow-up. INTERVENTION: Thirty patients were treated with a simple shoulder sling and 30 patients with ESIN within 3 days after trauma. MAIN OUTCOME MEASUREMENT: Complications after operative and nonoperative treatments, Disabilities of the Arm, Shoulder and Hand (DASH) score and Constant Shoulder Score for outcome measurement, and clavicular shortening. RESULTS: Fracture union was achieved in all patients in the operative group, whereas nonunion was observed in 3 of 30 patients of the nonoperative group. Two symptomatic malunions required corrective osteotomy in the nonoperative group. Medial nail protrusion occurred in 7 cases in the operative group. Implant failure with revision surgery was necessary in 2 patients after an additional adequate trauma. DASH scores were lower in the operative group throughout the first 6 months and 2 years after trauma, with a significant difference during the first 18 weeks. Constant scores were significantly higher after 6 months and 2 years after intramedullary stabilization. Patients in the operative group showed a significant improvement of posttraumatic clavicular shortening; they were also more satisfied with cosmetic appearance and overall outcome. CONCLUSIONS: ESIN of displaced midshaft clavicular fractures resulted in a lower rate of nonunion and delayed union, a faster return to daily activities, and a better functional outcome. Clavicular shortening was significantly lower, and overall satisfaction was higher in the operative group.

Modified Prusik knot versus whipstitch technique for soft tissue fixation in anterior cruciate ligament reconstruction: a biomechanical analysis.

Appropriate graft tension and secure graft incorporation in bone tunnels are essential for successful anterior cruciate ligament (ACL) reconstruction using hamstring tendon autografts. Permanent viscoplastic elongation in response to cyclic loading in the early postoperative period and the interposition of suture material in the tendon-bone interface might negatively affect graft function and rigid graft incorporation in the bone tunnels. A modified Prusik knot is an alternative option to the commonly used whipstitch technique for soft tissue fixation in ACL reconstruction. This is a controlled laboratory study. Sixteen formalin-fixed human cadaver semitendinosus tendons were armed with a modified Prusik knot or a whipstitch and tested in a load-to-failure test with a constant displacement rate of 1 mm/s, 14 in the cyclic loading test with 100 cycles from 10 to 50 N followed by 100 cycles from 10 to 75 N. The modified Prusik knot showed smaller force-induced displacements and higher stiffness of the entire construct in the load-to-failure test. Smaller preconditioning displacements were the only significant differences in the cyclic loading test. The modified Prusik knot has equal or superior mechanical properties and provides a larger area in the tendon-bone interface without suture material compared with the whipstitch technique.