ORIGINAL ARTICLE Minimally Invasive Dynamic Hip Screw Prospective Randomized Trial of Two Techniques of Insertion of a Standard Dynamic Fixation Device A. Alobaid, MD,* E. J. Harvey, MD,* G. M. Elder, MD,† P. Lander, MD,‡ P. Guy, MD,§ and R. Reindl, MD* Objective: This study evaluates the safety and outcome of a mini- mally invasive technique for inserting a standard dynamic hip screw for intertrochanteric fractures. Hypothesis: The use of standard plate in a minimally invasive tech- nique is both possible and advantageous to patient outcome. Design and Methods: Prospective surgeon-randomized blinded outcome clinical study comparing new technique to conventional technique. Main Outcome Measure: Pain, operative time and mean hemo- globin drop in percutaneous hip fixation. Results: The minimally invasive technique had significantly less blood loss (P < 0.001), operative time (P < 0.001) and a trend to less morphine use. Conclusions: Minimal invasive technique significantly reduces blood loss and operative time for fixation of intertrochanteric hip frac- tures without sacrifice of fixation stability or bone healing. Key Words: hip fracture, minimally invasive technique, intertro- chanteric, percutaneous, lower extremity, dynamic hip screw (J Orthop Trauma 2004;18:207–212) H ip fractures are among the most common fractures en- countered in orthopedics. Approximately 250,000 to 300,000 fractures of the proximal part of the femur occur in the United States each year. 1,2 The cost of treating these fractures is estimated to be 16 billion dollars per year. 2 Although other options have been used, 3–7 the dynamic hip screw with side plate (DHS) is the standard type of fixation used for intertro- chanteric fractures in most centers. 1,8–11 Attempts have been made to find less invasive tech- niques to simplify surgery and minimize complications by re- ducing surgical time and blood loss. 3,5,7,12 Most of these pa- pers have highlighted custom implants or required purchase of alternative devices by the hospital. Proximal femur blood sup- ply and its ramification on fracture healing and implant fixa- tion has begun to be clarified. 13–16 Approaches that minimize blood loss and soft-tissue stripping seem to be desirable in most fracture situations. 13,16,17 In this study, a standard DHS is used in a minimally in- vasive technique. The exposure is less invasive than the stan- dard technique with intent to minimize blood loss, preserve the soft tissue envelope, diminish the postoperative pain, and en- courage early ambulation. MATERIALS AND METHODS An assessment of the vasculature of the proximal femur was performed in preparation for this clinical study. An inde- pendent cohort of patient angiograms from the radiology li- brary was reviewed. The purpose was to determine if the first perforator artery (transverse branch of the lateral circumflex artery) was at sufficient distance from the surgical site to safely perform percutaneous incisions during surgery without fear of uncontrolled bleeding (Fig. 1). The concern was that vessels not ligated under direct vision could be a potential source of bleeding during the procedure or a source of hematoma in the postoperative period (especially in the anticoagulated patient). A retrospective angiographic assessment of arterial anatomy was accomplished. An independent radiologist (P.L.) on re- view of radiographs determined what the distance was from the intertrochanteric line to the first perforator. This is a poten- tial “safe zone” where it would be possible to ream and intro- duce a lag screw and plate without necessarily visually identi- fying a major branch of the femoral artery. A total of 14 lower Accepted for publication December 12, 2003. From the *Department of Orthopaedic Surgery, Montreal General Hospital, Montreal, Quebec, Canada, †Department of Orthopaedic Surgery, Sault Ste Marie Hospital, Sault Ste Marie, Ontario, Canada, ‡Department of Radiology, University of Alabama, Birmingham, AL, and §Department of Orthopaedic Surgery, University of British Columbia, Vancouver, British Columbia, Canada. This study uses approved internal fixation devices. No benefits of any kind were received by the authors for participation in this study. Reprints: Edward J. Harvey, MD, MSc, Department of Orthopaedic Surgery, Montreal General Hospital, Room B5.159.5, 1650 Cedar Avenue, Montreal, Quebec H3G 1A4, Canada (e-mail: ejharvey@hotmail.com). Copyright © 2004 by Lippincott Williams & Wilkins J Orthop Trauma • Volume 18, Number 4, April 2004 207