Failure of internal fixation of femoral cervicotrochanteric fractures occurs mainly due to poor fracture reduction, poor fixation techniques, incorrect implant use, or a poor biology or blood supply of the involved bone. Nonunion and malunion of femoral neck fractures in younger patients can be treated using head-preservation procedures, such as revision fixation, bone-grafting,[11, 12] or valgus osteotomy;[9, 13, 14] otherwise, joint replacement procedures can be employed.
Head-preservation techniques are technically difficult and are not commonly performed. Predictors of success in head-preservation surgery include patient-related factors and surgeon-related factors. Patient-related factors include patient age, associated medical co-morbidities, bone quality (osteoporosis), degree of comminution, fracture pattern, fracture alignment, and status of the hip joint, while surgeon-related factors include bone biology, soft-tissue handling, osteotomy method, and type of implant used in fixation. Backup plans are always required when performing such procedures. Valgus osteotomy corrects the varus deformity of a proximal femoral fracture and converts shear forces into compressive forces on the fracture plane. Certain criteria must be fulfilled when performing corrective osteotomy in order to attain a high success rate and good reproducibility for the treatment of femoral neck nonunion, especially in patients of a younger age in whom joint replacement surgery may not be the best option. Various fixation devices have been mentioned in the literature, consisting mostly of a DHS or blade plate. Pre-operative planning is essential in order to calculate the correction angle for the intended osteotomy.
Valgus osteotomy fixation with blade plates has been described in the literature by several authors.[7, 18–20] Blade plates have excellent rotational control but are technically difficult to use. Varghese et al. studied 32 patients who developed femoral neck non-unions and were treated using valgus osteotomy and blade-plate fixation. Although there was radiographic evidence of ONFH in 13 cases, only 2 required conversion to arthroplasty, illustrating that this complication is not always functionally devastating. Use of a DHS allows controlled dynamic collapse at the fracture site, and counteracts the shear forces and varus displacement; however, it does not resist rotation during insertion, which can be managed using a de-rotational screw. In our study, some, but not all, intracapsular fractures required the use of a de-rotational screw, probably owing to callus formation at the fracture site. Several authors have described valgus osteotomy and DHS fixation.[22–25]
The biomechanical basis of valgus reorientation osteotomy is the conversion of the nonunion plane to a more horizontal plane, rendering it perpendicular to the axis of load transmission, and thus creating a more favorable fracture-healing environment. For valgisation osteotomy, full-wedge, half-wedge and no-wedge techniques have been described. Hartford et al. used a full-thickness laterally-based wedge. Schoenfeld et al. removed a partial-thickness wedge to minimise limb length, but noted that partial-thickness wedge osteotomy may decrease the surface area of contact and increase the chances of implant failure. Both techniques require extensive pre-operative sketching and templating to achieve the desired result. The LLD in the series of Hartford et al. was 1 cm, probably owing to use of the full-thickness wedge technique. Gavaskar and Chowdary described a new technique of sliding subtrochanteric osteotomy and DHS fixation, with no wedge removal. They explained that their technique involved an oblique osteotomy just below the lesser trochanter with no wedge removal, and therefore there was no need for preoperative templating. They claimed that removing wedges may hinder limb-length restoration, requires careful planning and templating, and increases the surgical duration and blood loss. They added that their osteotomy technique can achieve a larger degree of correction with a wide contact area, and involves minimal lateral displacement of the distal fragment. In addition, they recorded a shorter operating duration and less blood loss as compared with the series of Hartford et al. and Schoenfeld et al. Valgisation osteotomy performed at the intertrochanteric area has several advantages: osteotomy at this level provides an adequate bone bridge between the osteotomy and the implant footprint; the technique is easier than osteotomy in the subtrochanteric area; and bone-healing is faster at the intertrochanteric cancellous osteotomy site. Furthermore, it is easier after employing this technique to set the femur stem in a total hip arthroplasty than following subtrochanteric osteotomy in cases of advanced ONFH or failed valgus osteotomy. Our basically no-wedge technique involved osteotomy of the proximal femur at the intertrochanteric region closer to the original fracture plane, which improved the drawbacks associated with subtrochanteric osteotomy, such as limitations in the correction angle and leg-lengthening.
Our osteotomy was of a staggered shape with asymmetrical limbs. The short limb on the lateral aspect of the proximal femur facilitated medialization of the femoral head, while the long limb on the medial aspect was used to correct the LLD and preserve more calcar bone for mechanical stability after the osteotomy. The shape of the osteotomy enabled the proximal fragment to buttress against the distal fragment to avoid translation. Our aim was to make the original fracture plane perpendicular to the direction of the joint reaction force. Applying such a valgus correction indeed converted the shear force on the fracture plane to a compression force during weight-bearing and enhanced fracture-healing.[23, 24] Indeed, we observed that the original fracture healed (average, 17.2 ± 6.3 weeks) faster than the osteotomy site (average, 5.8 months).
All our osteotomies were fixed with a DHS angled at either 135° (11 patients) or 150° (10 patients). The original fracture and the osteotomy site healed uneventfully, with the exception of the 2 cases of early failure. The blood supply to the femoral head appeared not to be violated by the osteotomy. Before the salvage osteotomy, 6 hips showed evidence of the presence of ONFH with either cystic lesions or sclerotic change of the femoral head. Of the 6 cases of ONFH, 3 hips slowly progressed to advanced collapse after 3 years, 11 years, and 15 years, respectively; the other 3 hips were stabilized with acceptable functional results. No new onset of ONFH was noted. Subcapital fracture presented another risk of failure. Early failure was experienced in 2 hips, in which the capital fragment had an inadequate bone stock for secure purchase and fixation. The other hip had an inadequate blood supply for revascularization. It is worth noting that the medullary canal of the proximal femur was not markedly distorted after this intertrochanteric osteotomy. Re-osteotomy was not needed to realign the medullary canal in the 5 failed cases when hip arthroplasty was performed, and a standard cementless press-fitting hip prosthesis could be used. No surgical difficulties were encountered in applying femoral stems through the osteotomized bone.
Limitations of our study were due to the fact that it was a cohort study of a small group, and did not include a comparison group. A comparison group of patients who underwent a different osteotomy for failed femoral cervicotrochanteric fractures might be required in order to justify our technique as a valid salvage option. Nevertheless, patients suffering from malunion or nonunion of a proximal femoral fracture should be managed using a salvage hip procedure whenever this is feasible. Attempting to save the native hip joint in patients of a younger age (under 55) should be the priority whenever this can be performed safely, efficiently, and with little adverse sequelae. Patient selection is crucial when considering such a treatment option.