ULTRASOUND FOR THE EARLY DIAGNOSIS OF TIBIAL FRACTURE-HEALING AFTER STATIC INTERLOCKED NAILING WITHOUT REAMING - CLINICAL-RESULTS

Objective: Based on the results of a pilot study indicating the potent ial value of ultrasound (US) as a diagnostic tool for the early assess ment of fracture healing and the related need for secondary operative procedures in patients treated by statically locked intramedullary (IM ) nailing without reaming, a protocol was established for a larger sca le prospective trial. The purpose of this study was to evaluate the ou tcome of this follow-up trial. Design/Methods: All skeletally mature p atients admitted to the Henry Ford Hospital (Detroit, Michigan) from J anuary 1993 to August 1994 who had sustained an acute fracture of the tibial shaft and who were treated by statically locked IM nailing, wit hout reaming, were candidates for study. Forty-seven patients with fif ty fractures that could be evaluated by US were included. The adopted determinants for fracture healing were complete disappearance of the G VI nail on US examination performed at six weeks postoperatively, or p rogressive disappearance of the nail noted between the initial six-wee k study and a second nine-week US examination, both in conjunction wit h periosteal callus formation. Radiographs were obtained to monitor ma intenance of reduction and to further evaluate fracture healing. Resul ts: Of thirty-eight fractures with a positive US (thirty-two at six we eks, six at nine weeks), thirty-seven healed uneventfully, a positive predictive value of 97 percent. Radiographic fracture healing was not evident until. on average, nineteen weeks after injury. The single fal se-positive fracture progressed to nonunion. Of the twelve fractures w ith negative US studies, ten underwent secondary procedures (nine dyna mization, one bone graft), with four progressing to nonunion. Two pati ents refused secondary surgery; screw failure occurred in both. Otherw ise, there were no hardware failures in this series. Conclusions: The results of this study indicate that US may provide important prognosti c information concerning fracture healing after unreamed tibial nailin g, upon which subsequent treatment can be based.