Fatigue failure of the sliding hip screw - clinical and biomechanical analysis.

The study was aimed at the clinical and biomechanical analyses of the sliding hip screw breakage with the use of finite element method. We have identified two patients with the sliding screw breakage. In the first patient, the biomechanical analysis revealed the reduced stress values σHMH not exceeding the yield limit or strength limit of the implant. The yield limit was exceeded in second one. Clinical and biomechanical analyses have demonstrated that adherence to technical requirements of the appropriate osteosynthesis implementation is the principal condition of timely healing since it prevents the material failure.

The results of primary repair after distal biceps tendon rupture.

OBJECTIVE: The aim of the study was to present the long term results of primary tenodesis in the treatment of distal biceps tendon rupture. METHODS: Patients previously treated for distal tendon rupture were evaluated. In all cases anatomical reattachment with a single-incision through the anterior approach was performed with either a screw and washer (modified McReynolds technique) or a Mitek Anchor. Analysis was performed using clinical and radiological examination and DASH score at the end of 2011. RESULTS: Twenty-one patients (21 males; mean age: 47.5 years) were treated for distal biceps tendon rupture. Fixation was performed using the modified McReynolds technique in 11 and Mitek Anchor in 10 patients. The McReynold technique had excellent result in 63.6% of patients, a 9.1% risk of implant failure and a mean DASH score of 7.8. The Mitek Anchor technique had excellent result in 60% of patients, a 10% risk of implant failure and a mean DASH score of 7.4. CONCLUSION: Operative treatment for distal biceps tendon rupture appears to be a safe and effective method and consistently yields good results.