Valgus-impacted subcapital neck of femur fractures: a systematic review, meta-analysis with cost analysis of fixation in-situ versus nonoperative management

Background: The management of the valgus-impacted neck of femur fracture (AO/OTA 31-B1) remains contentious. The objective of this study was to determine whether operative intervention is cost-effective.Methods: We conducted a systematic review using electronic databases (Medline, Embase, Cochrane, Ebsco, Scholar) identifying studies published in the English language concerning valgus-impacted neck of femur fractures until June 2022. Additional studies were identified through hand searches of major orthopaedic journals, and bibliographies of major orthopaedic textbooks. MeSH terms (hip fracture and femoral neck fracture) and keywords (undisplaced, valgus-impacted, valgus, subcapital, Garden) connected by the Boolean operators "AND" and "OR" were used to identify studies. 2 reviewers independently extracted the data using standardised forms and recording spreadsheet. Methodological validity prior to inclusion in the review using standardized critical appraisal instruments from the Joanna Briggs Institute Meta-analysis of Statistics Assessment and Review Instrument. Meta-analysis was undertaken. Outcome measures were rate of displacement, avascular necrosis, non-union, mortality and requirement of further operative intervention. A cost utility analysis was then conducted to compare the 2 groups on the basis of the cost of initial treatment and the potential requirement of secondary intervention to hemiarthroplasty.Results: 47 studies met the inclusion criteria. Meta-analysis data demonstrated a significant difference in the displacement rate of 22.8% and 2.8% between the nonoperative and internal fixation groups respectively (p = 0.05). The overall incidence of further operative intervention for each group was 23% and 10% respectively. There was no significant difference with respect to avascular necrosis, mortality or union rates. The cost utility analysis revealed nonoperative management to be approximately 60% more costly than initial internal fixation when the costs of subsequent surgery were included.Conclusions: This meta-analysis of the existing literature concludes that whilst nonoperative management is possible for valgus impacted neck of femur fractures, it is associated with higher complication rates and greater expense than management by internal fixation.