Intertrochanteric Fractures Should Be Treated with Intramedullary Fixation

Allan S.L. Liew, M.D., FRCSC
Director of Orthopaedic Trauma, The Ottawa Hospital
Site Chief of Orthopaedic Surgery, Civic Campus
Assistant Professor of Surgery, University of Ottawa
Ottawa, ON

To avoid confusion, a clarification of the terms of reference is required. By definition, intertrochanteric fractures refer to fractures that occur between the greater and lesser trochanter, namely transverse and reverse obliquity type fractures. Others have generalized and included pertrochanteric fractures, that is, those fractures that run from the greater to lesser trochanters, such as the more common 2, 3, and 4 part fractures. For the purposes of this commentary, all of these fracture types will be included.

 

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Figure 1 a,b: Unstable intertrochanteric fracture with comminution of lateral cortical buttress and posteromedial calcar.
Figure 1c,d: Maintenance of anatomical reduction at 1 month postop with intramedullary device.

It is helpful to stratify these injuries into two categories; stable (some 2 and 3 part pertrochanteric fractures) and unstable (transverse and reverse obliquity intertrochanteric, and most 3 and 4 part pertrochanteric) fractures. The most common implants used in the treatment of intertrochanteric fractures are cephalomedullary intramedullary nails and extramedullary sliding hip screw devices.

From a biomechanical perspective, an intramedullary device has the advantage as the nail is closer to the weight-bearing axis, allowing it to function better as a load sharing device and reduce stress on the junction between the hip screw and the axial support. This advantage is more readily apparent in the unstable fracture patterns where the comminuted bone is less able to contribute to axial loading, and where the obliquity of the fracture does not result in fracture compression with weight bearing1.

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Figure 2a,b: Unstable intertrochanteric fracture with transverse fracture orientation.
Figure 2c: Traction view for preoperative planning.
Figure 2d: Maintenance of anatomical reduction with intramedullary device.

In stable 2 and 3 part pertrochanteric fracture patterns, the biomechanical advantages of a nail are not as apparent, so in the current economic environment of limited resources, it may be more prudent to use a much cheaper sliding hip screw. However it has been observed that a significant number of these patients subsequently sustain a distal femoral fracture, prompting the hypothesis that protection of the entire femur with a long intramedullary device at the initial proximal femoral injury may prevent a subsequent distal injury. The cost savings of avoiding a second admission and surgery would more than offset the initial cost difference between implants. The additional cost of a trochanteric side plate or other adjunctive fixation with a sliding hip screw for unstable fractures negates the issue of cost difference between intra and extramedullary implants.

Obtaining a satisfactory reduction that approximates anatomic alignment is important for either fixation method. However, the intramedullary device is better able to maintain this reduction by limiting lateral displacement of the head and neck segment relative to the shaft when it buttresses against the intramedullary nail, while still allowing for compression of the fracture fragments. With a sliding hip screw, particularly when the lateral cortical buttress is comminuted or with reverse oblique patterns, over-medialization of the femoral shaft typically occurs.

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Figure 3a,b: Unstable intertrochanteric fracture and ipsilateral distal femoral fracture.
Figure 3c: Initial treatment with sliding hip screw and inability to obtain or maintain satisfactory reduction.
Figure 3d: Revision with unicortical reduction plate and intramedullary fixation for maintenance of anatomic reduction of both proximal and distal fractures.

The complication of intra-operative proximal femoral fracture with nail insertion was seen with earlier generation implants and surgical technique but has been addressed with the current smaller diameter implants and appropriate proximal reaming2, 3; these fractures are now rarely seen and are more commonly related to surgical misadventure than nail design. The overall rate of other complications such as infection, non-union, and implant cut-out are not significantly different compared to sliding hip screws2. Other factors such as operative time, blood loss, and fluoroscopy time have not conclusively been shown to be different between the two implants.

It has been proposed that the abductors are damaged with a trochanteric insertion point for an intramedullary implant affecting long-term functional outcome and persistent limp; however, this has not been shown4. Contrarily, there is a trend towards earlier ease of mobilization, perhaps due to better fracture stability and less self-limitation of weight bearing5. There are also concerns that intramedullary implants remove too much proximal femoral cancellous bone, but in the elderly patient population who are usually afflicted with this injury, the trabeculae have thinned out to the point where the proximal femur is virtually hollow except for the 5-10mm of subchondral or endosteal bone, thus the nail merely occupies an empty space.

There are cases where the use of an intramedullary device is not possible, such as with a long stem femoral revision total knee or significant pre-existing femoral diaphyseal deformity. In unstable fractures, a sliding hip screw would not be the best implant either, due to potential loss of anatomical reduction. A better implant in this scenario would be a non-sliding fixed angle device such as a blade plate or proximal femoral locking plate. A sliding hip screw could be used, however an additional trochanteric side plate would be recommended to prevent medialization of the femoral shaft.

Maintaining an anatomic reduction is a key factor in achieving union and optimal function. For stable fracture patterns, both IM and extramedullary devices can achieve satisfactory outcomes. In unstable patterns, there is growing evidence that an intramedullary device offers greater biomechanical stability and earlier return to function without a significant difference in complications. Intramedullary devices may also confer the advantage of 'whole bone' fixation which may reduce the future fracture risk in severely osteoporotic patients. Further randomized controlled trials are required to further clarify the differences in short and long-term outcomes such that appropriate evidence-based decisions can be made in implant selection.

References

  1. Kuzyk P.R., Lobo J., Whelan D., Zdero R., McKee M.D., Schemitsch E.H. Biomechanical evaluation of extramedullary versus intramedullary fixation for reverse obliquity intertrochanteric fractures. J Orthop Trauma 2009; 23(1):31-8.
  2. Parker M.J., Handoll H.H. Gamma and other cephalocondylic intramedullary nails versus extramedullary implants for extracapsular hip fractures in adults. Cochrane Database Syst Rev 2005;(4):CD000093.
  3. Bhandari M., Schemitsch E., Jonsson A. Zlowodzki M., Haidukewych G.J. Gamma nails revisited: gamma nails versus compression hip screws in the management of intertrochanteric fractures of the hip: a meta-analysis. J Orthop Trauma 2009; 23(6): 460-4.
  4. Ricci W.M., Schwappach J., Tucker M., Coupe K., Brandt A., Sanders R. et al. Trochanteric versus piriformis entry portal for the treatment of femoral shaft fractures. J Orthop Trauma 2006; 20(10):663-667.
  5. Ziran B.H., Heckman D.S., Olarte C.M., Chou K., Baranick J. Intrameduallary hip screw versus standard compression hip screw: early postoperative rehabilitation comparisons. Orthopedics 2009; 32(2):83.

 

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