Intertrochanteric (IT) hip fractures represent a common pathology in the elderly and are the source of significant economic burden in the United States Health Care System. In 2014, the annual incidence of IT hip fractures in the United States was found to be 171 per 100,000 individuals aged over 65 representing 42% of all hip fractures. The average estimated cost for a single IT hip fracture hospitalization was found to be $52,215 with an overall annual cost to the health system of $2.63 billion dollars in the first year after injury.1 Among the most important predictors of both patient outcomes and subsequent health care costs is the initial presenting fracture pattern. Evans initially published his classification for IT fractures and 1949 and divided fracture patterns into 2 subtypes based on fracture stability.2 In 1975, Jensen made modifications to the original Evans classification and described type I, or stable fracture patterns, which were considered nondisplaced fractures without the presence of comminution. Type II fractures were described as displaced fractures with restoration of overlap of the medial cortical buttress after reduction. Conversely, unstable fractures were considered those patterns that demonstrated comminution of the lateral cortex, reverse oblique patterns, and fractures with extension into the subtrochanteric region.3 Unstable fractures represent a unique challenge for fixation. Historically, IT fractures were treated with the sliding hip screw (SHS). However, failure rates of SHS fixation in unstable IT fractures have been found to be as high as 26%.4 The cephalomedullary nail (CMN) was introduced to address this problem and is now frequently utilized in the treatment of unstable IT fractures. CMN fixation has been shown to have significantly lower rates of cut-out and fixation failure when compared with SHS in unstable IT fractures.5 This has led to a significant increase in the use of CMN for IT fracture fixation and it is now the most frequently utilized implant for this pathology worldwide.1

The increased biomechanical stability afforded by CMN fixation has led to improved outcomes in unstable IT fracture patterns. However, it remains a technically demanding surgical intervention with many pitfalls to be avoided to achieve fracture stability. Importantly, adequate intraoperative reduction of the calcar has been shown to be among the strongest safeguards against eventual failure of CMN fixation in both stable and unstable IT fractures.5 Perfect anatomic reduction of the fracture also affords the most predictable stability by increasing the interdigitation of fracture edges.5 Thus, the quality of intraoperative reduction before fixation remains among the most essential principles to achieving successful fixation of unstable IT fractures.5 One important consideration for reduction when utilizing a CMN is the presence of the “wedge effect” during nail insertion which occurs when the nail is inserted through the greater trochanter and causes fracture site distraction with associated lateralization of the femoral shaft. This culminates in varus malreduction of the fracture. Basicervical fracture patterns also represent a unique challenge for obtaining adequate reduction due to the inherent presence of instability in the sagittal plane5 and associated rotational deforming forces (Fig. 1). Thus, a reduction technique that provides stabilization to safeguard against both the wedge effect, as well as rotational loss of reduction, is needed to adequately address these common pitfalls when surgically treating IT fractures and basicervical femoral neck fractures.

FIGURE 1:

Graphical representation of the sagittal instability and rotational deforming forces encountered during lag screw insertion in basicervical femoral neck fractures.

We present a novel surgical technique for simultaneously counteracting rotational forces in basicervical femoral neck fractures during lag screw insertion and avoiding the wedge defect in IT hip fractures during CMN insertion. Our technique involves the percutaneous insertion of 1 or 2 transversely oriented partially threaded guide pins across the femoral neck and into the medial calcar. The pins are placed peripherally anterior to the intended path of the nail and have 2 solid points of bony fixation in the lateral femoral cortex and the calcar of the femoral neck. This has the advantage of providing both a provisional reduction of the calcar while also producing a safeguard against two commonly encountered pitfalls in CMN fixation of IT and basicervical femoral neck fractures with a single technique.

SURGICAL TECHNIQUE

The patient is positioned supine on the fracture table and placed into a well-padded traction boot on the operative side. A perineal post is placed between the legs and the nonoperative lower extremity is elevated out of the field utilizing an articulating well-leg holder and placing the leg in abduction and external rotation. Fluoroscopy is brought in from the contralateral side and provisional reduction is obtained under image intensification through the use of traction and rotation in the axial plane. After obtaining adequate preliminary reduction, the operative leg is prepped and draped in the standard surgical manner. Image intensification is then utilized to determine the optimal starting point for the transversely oriented pin. After identifying the desired starting point, a percutaneous stab incision is made over the lateral femur, and the pin is placed against the lateral cortex. The 3.2 mm partially threaded pin is then placed from lateral to medial into the calcar of the femoral neck ensuring it remains anterior to the projected path of the nail. If the bone quality is found to be poor, a second pin can be placed in a similar manner just superior to the first pin. In elderly patients with porous bone, multiple pins can be placed to provide more points of fixation as long as they remain outside of the intended nail trajectory The pin can then be utilized as a joystick to help maintain reduction of the fracture if necessary. In addition, a T-handle can be placed onto the end of the pin and back slapped in a lateral direction to provide a more stable reduction of the femoral calcar.

After confirming that the reduction remains adequate, the CMN is then inserted with the standard technique. The guide pins remain in place during the insertion of the lag screw to counteract any sagittal instability present. After the distal interlocking screw is placed and the lag screw is successful in achieving compression across the fracture site, the pins are then removed (Figs. 2 and 3).

FIGURE 2:

An elderly woman who suffered a ground-level fall resulting in an intertrochanteric (IT) femur fracture subsequently underwent fixation with a cephalomedullary nail (CMN) utilizing our described technique for provisional fixation.

FIGURE 3:

An elderly woman who suffered a ground-level fall resulting in an IT femur fracture subsequently underwent fixation with a CMN utilizing our described technique for provisional fixation.

EXPECTED OUTCOMES

To our knowledge, there are no other descriptions of this particular technique in the setting of CMN or SHS fixation. This technique is a simple and cost-effective method for providing reliable provisional fixation during surgical stabilization of unstable IT fractures or basicervical femoral neck fractures. Further, it represents a single technique that can be utilized to simultaneously counteract 2 of the most common deforming forces encountered in CMN insertion and lag screw insertion respectively. The strong fixation obtained across the lateral femoral cortex and the calcar can resist sagittal rotational forces, as well as hold fracture reduction, to avoid the wedge effect in IT fractures ultimately leading to a lower risk of malreduction of these common fracture patterns. To date, we have not had any issues with guide wire breakage or any other complications specifically related to the use of this technique.

COMPLICATIONS

This technique requires frequent fluoroscopic imaging to ensure adequate percutaneous pin placement along the calcar. When reviewing case times in which this technique has been used, fluoroscopy times were only minimally increased on average requiring <5 additional images. Another theoretical risk of this technique is perforation of the femoral head which could cause lead to the need for conversion to total hip arthroplasty. In addition, the technique does have a learning curve which could lead to increased operative times early on. To this point, this technique has been used at our institution for fracture reduction in nearly 50 patients and has not resulted in a significant increase in operative times. Despite these potential complications, it remains a safe and reproducible technique for avoiding the wedge effect or fracture rotation during component placement in the surgical treatment of IT or basicervical femoral neck fractures.

REFERENCES 1. Adeyemi A, Delhougne G. Incidence and economic burden of intertrochanteric fracture: a medicare claims database analysis. JB & JS open access. 2019;4:e0045. 2. Evans EM. The treatment of trochanteric fractures of the femur. J Bone Jt Surg. 1949;31-B:190–203. 3. Jensen JS. Classification of trochanteric fractures. Actaorthop Scand. 1980;51:803–810. 4. Yong CK, Tan CN, Penafort R, et al. Dynamic hip screw compared to condylar blade plate in the treatment of unstable fragility intertrochanteric fractures. Malays Orthop J. 2009;3:13–18. 5. Whale CS, Hulet DA, Beebe MJ, et al. Cephalomedullary nail versus sliding hip screw for fixation of AO 31 A1/2 intertrochanteric femoral fracture: a 12-year comparison of failure, complications, and mortality. Curr Orthop Pract. 2016;27:604–613.