Midterm Radiographic and Functional Outcomes of the Anterior Subcutaneous Internal Pelvic Fixator (INFIX) for Pelvic Ring Injuries.

Abstract

To describe our experience using the anterior internal pelvic fixator (INFIX) for treating pelvic ring injuries. Case Series. Level 1 Trauma Center. Eighty-three patients with pelvic ring injuries were treated with INFIX. Follow-up average was 35 months (range 12-80.33). Surgical treatment of pelvic ring injuries included reduction, appropriate posterior fixation, and INFIX placement. Reduction using the pelvic deformity index and pubic symphysis widening, Majeed functional scores, complications; infection, implant failure, heterotopic ossification (HO), nerve injury, and pain. All patients healed in an appropriate time frame (full weight bearing 12 weeks postoperation). The average pelvic deformity index reduction (injury = 0.0420 ± 0.0412, latest FU = 0.0254 ± 0.0243) was 39.58%. The average reduction of pubic symphysis injuries was 56.92%. The average Majeed score of patients at latest follow-up was 78.77 (range 47-100). Complications were 3 infections, 1 case of implant failure, 2 cases implantation too deep, 7 cases of lateral femoral cutaneous nerve irritation, and 3 cases of pain associated with the device. HO was seen in >50% of the patients, correlated with increased age (P < 0.007), injury severity score (P < 0.05) but only 1 case was symptomatic. The pelvic injuries had good functional and radiological outcomes with INFIX and the appropriate posterior fixation. The downside is removal requiring a second anesthetic, there is a learning curve, HO often occurs, the lateral femoral cutaneous nerve may get irritated which often resolves once the implants are removed. Surgery-specific implants need to be developed. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.