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Femoral neck nonunion in young patients has always been a difficult problem to deal with for surgeons. Numerous surgical procedures to address either the biological or mechanical issues at the nonunion have been described and most of them have been associated with variable results. Isolated biological augmentation is often associated with poor results and some techniques like vascularized grafting may require not so commonly available expertise. Valgus osteotomy is aimed to correct the abnormal fracture biomechanics associated with femoral neck fractures. By altering the nature of force transmission across the nonunion, shear forces are converted into compressive forces that lead to rapid osseous union without the need for bone grafting. Though the principles are sound and were described a long time ago, the technical aspects have evolved over time. Various modifications have been described to overcome shortcomings such as limb length discrepancy, reduction of femoral offset, alteration in mechanical axis, and the overall proximal femur anatomy. In this review, we look back at the fundamental principles and recent literature on the results of valgus intertrochanteric osteotomy for femoral neck pseudoarthrosis. We also highlight the important need for accurate preoperative planning and surgical execution. Lastly, we elaborate on the technical improvisations that have happened over time in order to improve functional results and to minimize complications and poor outcome after a valgus osteotomy.

Background Metaphyseal fracture healing in the distal femur requires a stable biomechanical environment. The presence of arthritis-induced coronal-plane knee deformities can cause deviation of the mechanical axis, which results in asymmetric loading and increased bending forces in fractures of the distal femur metaphysis. This predisposes patients to nonunions or loss of fixation. Concurrent TKA during revision osteosynthesis might facilitate fracture healing, owing to its ability to correct coronal alignment, thereby restoring normal loading patterns at the fracture site, but to our knowledge, this has not been studied. Questions/purposes (1) Does TKA with concurrent revision internal fixation achieve fracture union in patients with coronal-plane deformity from knee arthritis and nonunion or loss of fixation in distal metaphyseal femoral fractures? (2) What is the survivorship and what are the short-term functional outcomes after these reconstructions? (3) What complications occur after these reconstructions? Methods Between 2015 and 2018, one surgeon treated 16 patients with a distal metaphyseal femur fracture nonunion and/or loss of fixation using concurrent TKA plus revision internal fixation. Autologous iliac crest bone grafting was performed in five patients with evident gaps at the fracture site. The indications for the procedure included patients older than 55 years of age presenting with a nonunion and/or loss of fixation of a distal metaphyseal femur fracture in the setting of painful Ahlbäck Grade III to V knee arthritis with an associated coronal-plane deformity. All patients meeting these indications were treated with this approach during the study period. Fracture union assessed by radiological bridging of at least three cortices, TKA survival free from revision due to any reason, coronal-plane correction using tibiofemoral angle, and patient mobility status assessed presurgery and at follow-up using the Parker mobility score (scored 0-9 points, with 9 indicating best mobility) were assessed by two surgeons who were not involved in the care of the study patients. Immediate and delayed complications were recorded. Patients were followed for a minimum of 24 months. The median (range) follow-up was 38 months (27 to 52 months). Results All fractures united after concurrent TKA plus revision internal fixation. In all, 14 of 16 fractures healed before 5 months, while the remaining two fractures united by 6 months. Survivorship analysis revealed a TKA component survival of 94% (95% CI 63% to 99%) at 52 months. The median (range) preoperative Parker mobility score of 5 points (3 to 8) improved to 7 points (2 to 9) at 12 months postoperatively and was maintained at last follow-up (p = 0.001). Four patients experienced complications; these were (1) prolonged surgical wound drainage resulting in debridement and polyethylene liner exchange, (2) deep knee infection needing a staged revision, (3) popliteal vein thrombosis, and (4) prolonged graft site pain. Conclusion Concurrent TKA plus revision internal fixation is effective for achieving union in patients with distal metaphyseal femur nonunion and loss of fixation in the setting of coronal-plane deformity induced by knee arthritis. Short-term TKA survival and improvement in patient mobility are excellent, although 4 of 16 patients in this report experienced complications, as one might expect with a procedure of this magnitude. Based on our results, correction of arthritis-induced coronal-plane knee malalignment can be considered part of the surgical strategy when treating such distal metaphyseal femur nonunions. Better preoperative evaluation of the deformity and control-based comparative studies can further validate the utility of this technique. Level of Evidence Level II, therapeutic study.