Session I - Pelvic Trauma

Distraction External Fixation in Lateral Compression Pelvic Fractures

Carlo Bellabarba, MD; Brett R. Bolhofner, MD; Michael J. O'Boyle, MD; William M. Ricci, MD, Florida Orthopaedic Institute and Bayfront Medical Center, Tampa-St. Petersburg, FL

Hypothesis/Purpose: The goal of the present study is to analyze the treatment of type B lateral compression injuries of the pelvis using closed reduction and placement of a two-pin external fixator through the anterior inferior iliac spines. The techniques for pin placement and reduction maneuver are also described.

Methods: Between 1989 and 1997, 14 patients with lateral compression type B pelvic ring injuries with significant internal rotation of the affected hemipelvis (OTA classification 61-B2) presented to Bayfront Medical Center. Thirteen fractures were closed, and one was open. All patients were treated with closed reduction under general anesthesia and placement of a single-bar two-pin anterior external fixator through the anterior inferior iliac spines. Average age was 32 years (18-52 yr.), and mechanism of injury consisted of 11 motor vehicle accidents, 2 falls, and one industrial crush injury. Anterior injuries included 11 pubic ramus fractures and 3 locked symphyses. Posterior injuries consisted of 12 compression fractures of the sacrum and 2 pure sacroiliac joint injuries. Mean preoperative internal rotation deformity was 23 degrees (10-40 deg.), and average time from injury to the index procedure was 3.4 days (1-9 d.). Patients were followed at 4-week intervals until fracture healing and for a minimum of one year postoperatively, with an average follow-up of 45 months (12-107 mo.).

Results: A symmetric reduction of both hemipelves was achieved in all cases. Patients were allowed to bear full weight immediately and were able to do so without ambulatory assistive devices within an average of 12 days (3-18 d.), excluding those patients limited by simultaneous lower extremity injuries. Time to healing averaged 8.2 weeks (7-12 wk.), and no fixator required removal prior to complete healing. There were no delayed unions or nonunions, and none of the fractures displaced following initial reduction. Average surgical time was 37 minutes (25-60 min.) with an estimated blood loss of under 50 cc. in all cases.

Complications consisted of three minor pin tract infections which resolved with oral antibiotics, one temporary lateral femoral cutaneous nerve palsy, and one late pin tract abscess that resolved with local debridement following pin removal. There were no neurovascular complications. One patient continues to have complaints of low back pain 18 months post-injury despite computed tomopgraphy confirmation of sacral fracture union without foraminal narrowing.

Conclusions/Significance: The anterior distraction external fixator is an effective method for treatment of type B lateral compression injuries of the pelvic ring. Surgical time and blood loss are minimal, and patients can be effectively and rapidly mobilized with minimal pain. Based on our experience, we believe this method to be the treatment of choice for these fractures.