Surgical management of femur basicervical fractures (AO/OTA 31B3): A systematic review

BACKGROUND: Basicervical femoral fractures (AO/OTA 31B3) are considered extracapsular injuries located at the base of the femoral neck, with features intermediate between intracapsular and pertrochanteric fractures. Their anatomical "borderline" position and mechanical instability have led to uncertainty regarding optimal management. This systematic review aimed to evaluate outcomes of cephalomedullary nails (CMN), sliding hip screws (SHS) and hip arthroplasty (HA) for strictly defined basicervical fractures and to identify which treatment strategies are associated with fewer implant failures. METHODS: A systematic literature search (Medline/PubMed, Scopus, Cochrane) was performed according to PRISMA guidelines. English-language randomised controlled trials and prospective or retrospective observational studies were included if they specifically reported basicervical femoral fractures defined as AO/OTA 31B3 or as extracapsular fractures lateral to the femoral neck and medial to the greater trochanter without involvement of the lesser trochanter, treated with CMN, SHS or HA. Cadaveric, biomechanical and purely technical reports were excluded. Risk of bias was assessed using RoB 2 for RCTs and the Newcastle-Ottawa Scale for observational studies. Due to heterogeneity, data were synthesised descriptively. RESULTS: Sixteen studies with 1144 patients were analysed: 416 treated with CMN, 668 with SHS and 60 with HA. Overall implant failure occurred in 27 CMN cases (6.5%), 54 SHS cases (8.1%) and 2 HA cases (3.3%). Cut-out and non-union were the main failure modes after internal fixation, whereas avascular necrosis and new femoral neck fracture were rare. Across contemporary series, CMN and SHS showed broadly comparable failure patterns when adequate reduction and implant positioning were achieved. HA demonstrated low mechanical failure rates but was used in small, highly selected cohorts. Most studies were at least at moderate risk of bias. CONCLUSION: When basicervical fractures are strictly defined, both CMN and SHS appear to be acceptable options provided that anatomic or near-anatomic reduction and proper implant placement are obtained, while primary HA may be considered in frail elderly patients at high risk of fixation failure. Recognising basicervical fractures as a distinct entity and standardising their radiographic definition are essential to refine treatment algorithms, and high-quality prospective comparative studies are still needed. LEVEL OF EVIDENCE: I.