Pertrochanteric hip fracture fixation with 3 hole and 4 hole dhs side plates - A retrospective patient record review

Introduction: Dynamic hip screw fixation (DHS) with a 4-hole side plate and 4 bi-cortical screws is considered by many to be the standard implant for extracapsular hip fractures. The 4-hole side plate, however, has several disadvantages including longer incision, increase in operating time, bleeding and increased wound morbidity. Biomechanical studies have shown that most of the force in a 4-hole DHS fixation is borne by the proximal three screws. This study (specifically) compares the outcome of fixation using 3-hole and 4-hole DHS in extracapsular hip fracture fixations (with the hypothesis being that 3-hole plate is adequate even in unstable intertrochanteric fractures. Patients and Methods: A total of 72 consecutive patients who had DHS fixation with either a 3 hole or 4 hole DHS side plate and who were either directly operated or supervised by a single consultant were recruited. Fractures were classified using the AO fracture classification system as stable (AO/OTA 31A1–31A2.1) and unstable (31A2.2–31A3.3 subtypes) for ease of comparison. Failure was defined as metalwork breakage, nonunion, screw cut-out or pull out or any other complications of bone healing requiring a revision. Results: A total of 23 patients (68.1%) were female, whereas 49 patients (31.9%) were male. Fractures in 33 patients were classified as stable with the (AO/OTA 31A1–31A2.1) and unstable in 39 patients with (31A2.2–31A3.3 subtypes). Thirty-three (45.8%) patients had fixation with 3-hole side plate, whereas 39 (55.2%) patients had fixation with 4-hole side plate. In the 3 hole group, 17 patients had stable fractures, whereas 16 patients had unstable fracture configuration while in the 4-hole DHS side plate group, 16 patients had stable fracture configuration, whereas 23 patients had unstable fracture. The mean change in hemoglobin was lower for the 3-hole DHS group (3 hole-6.64 g/l versus 4Hole 12.41 g/l) (t = 1.732, P = 0.090, P ≤ 0.05). One patient in each group also had metalwork failure with screw cut-out through the head and the other being (screw breakage) complete failure of the screw necessitating conversion to total hip arthroplasty. Conclusion: Three-hole DHS plate offers comparable outcome with its 4-hole counterpart even with unstable intertrochanteric fractures, with slightly less blood loss and smaller scars.