Intertrochanteric fracture fixation with Dynamic Hip Screw: Is tip-apex distance measurement useful for predicting fixation failure?

Introduction: Application of dynamic hip screw (DHS) implant for the treatment of unstable intertrochanteric fractures continues to raise concern related to risk of lag screw cut-out with or without subsequent damage to the acetabulum. Measurement of tip-apex distances (TAD) has been recommended to guide the optimal placement of lag screw and to predict subsequent risk of screw cut-out. In this study, the value of TAD was evaluated to verify its usefulness. Methods: This is a retrospective study of 33 consecutive patients with intertrochanteric fracture treated with DHS. Demographic data of the patients were traced from their case notes. Post-operative radiographs were reviewed by focusing on measurement of TAD on anteroposterior and lateral radiographs. Radiographs at one year follow-up were reviewed to depict any fixation-related failure or complication. Results: Fifty two percent of patients did not achieved the recommended TAD of ≤ 25mm. The mean post-operative TAD was 25.9mm and elderly patients were likely to achieve TAD of ≤ 25mm. The overall complication rate of 6% was attributed to screw cut-out in two cases. The unstable left-sided fracture was identified to be a potential risk for screw cut-out or migration. Conclusion: TAD is a valuable measurement to guide optimal placement of lag screw during DHS fixation of intertrochanteric fracture.

Fixation Strategies to Prevent Screw Cut-Out and Malreduction in Proximal Humeral Fracture Fixation

Fixation of proximal humerus fractures with precontoured, fixed angle devices has improved operative management of these difficult injuries, particularly in patients with osteoporosis. However, recent data has revealed that fixation with these constructs is not without complications, particularly screw cut-out and loss of reduction. Multiple strategies have been developed to decrease the number of complications. We offer a surgical technique combining suture augmentation of the proximal humerus with locked plate fixation utilizing short screws.

Use of the Tip-Apex Distance in predicting Dynamic Hip Screw Cut Out in Intertrochanteric Fracture of the Femur in Asian Population

The objective of this study was to assess the rate of screw cut out in elderly patients treated with the dynamic hip screw and the relationship to the Tip Apex Distance (TAD). This is a retrospective radiological evaluation of 100 cases of elderly patients with intertrochanteric fracture treated with dynamic hip screw fixation surgically treated between 1998 and 2002. The incidence of screw cut out was assessed and correlation of risk of cut out with the TAD was assessed. The rate of screw cut out was 9.0% and the average length of time to screw cut out was 3.8 months (range, 1 to 6 months) postoperatively. The incidence of screw cut out increased significantly when the TAD was 20 mm or more. The screw cut out rates were 2.9%, 20.0%, 30.8%, 50% and 100% for TAD of 20-24 mm, 25-29 mm, 30-34 mm, 35-44 mm and > 45 mm respectively. Overall, a TAD of 20mm or more was associated with a statistically significant screw cut out risk in this Malaysian population.