Saturday, February 26, 2005
Osteoporotic pertrochanteric fractures successfully treated with external fixationBy Carolyn Rogers
Surgeons should consider external fixation with hydroxyapatite-coated pins as a treatment option for type A1, A2 pertrochanteric fractures (AO/Orthopaedic Trauma Association [OTA] classification) in patients with osteoporosis, according to researchers for Scientific Exhibit SE070. Advantages of this treatment include shorter operative time, negligible complications, no need for blood transfusions and superior fixation.
The investigators evaluated the outcomes of a series of osteoporotic pertrochanteric fractures treated with external fixation and hydroxyapatite(HA)-coated pins. Thirty-eight patients over the age of 65 with pertrochanteric fractures (AO type A1, A2) were treated with Orthofix pertrochanteric fixator (OPF). Under fluoroscopy, fractures were reduced with a slight valgus angulation on a fracture table. Four 1-cm skin incisions were made and four HA-coated pins were implanted-two in the femoral head and two in the proximal femoral diaphysis. The proximal pins implanted in the femoral head were either converging (19 patients) or parallel (19 patients). Weight bearing was as tolerated by the patient.
Average patient age was 78 years (standard deviation: ±8 years) and average bone mineral density was 497 g/cm² (±153 g/cm²). Intraoperative time was 37 minutes (±12 mins) and hospital stay was 7 days (±1 day). No postoperative blood transfusions were required.
Fixators were removed 12 weeks after surgery and pin extraction torque was measured. Femoral neck shaft angle was 133º (±4º) at 12 weeks and 132º (±4º) at 12 months. Medial displacement of the distal fracture fragment, limb shortening and fixation failure did not occur.
At the 3-year follow-up, the average Harris hip score was 61 (±21). (Eleven patients died prior to the 36-month follow-up.) No pin-tract infection occurred. Pin insertion torque was 1832 N/mm (±1275 N/mm), and pin extraction torque was 2648 N/mm (±1680 N/mm) (p<0.001). This is a significant result because it shows that pin fixation, a major concern with standard pins, was optimal. One patient with an intact fracture reduction at 12 weeks had a varus collapse of the fracture after fixator removal.
This study shows that treatment with OPF has several advantages in these fracture types. Operative time is short, complications are negligible and blood transfusions are not required. Due to the optimal osteointegrative ability of the HA-coated pins, fixation was well-maintained. The absence of an excessive sliding effect-a common feature of both dynamic hip screw and intramedullary nail treatment-prevented limb shortening and preserved the surgical reduction.
Researchers include Antonio Moroni, MD; Cesare Faldini, MD; Francesco Pegreffi, MD; Sandro Giannini, MD; and Amy Hoang-Kim, all of Bologna, Italy.