One Versus Two Screw Fixation in Minimally Invasive Hallux Valgus Surgery: A Systematic Review.

Minimally invasive surgery (MIS) for hallux valgus has evolved significantly, with ongoing debate about optimal fixation methods. Fourth-generation techniques typically use two metatarsal screws; however, single screw fixation may reduce operative time, radiation exposure, and cost. This systematic review compares clinical outcomes, radiographic results, and complications between one- and two-screw metatarsal fixation in minimally invasive hallux valgus correction. A systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines was conducted across MEDLINE, EMBASE, PubMed, and Cochrane databases from inception to March 2025. Studies comparing single versus two screw fixation in minimally invasive hallux valgus surgery were included. Risk of bias was assessed using the Risk Of Bias in Non-randomized Studies of Interventions (ROBINS-I) tool. Primary outcomes included radiographic parameters (Hallux Valgus Angle (HVA), Intermetatarsal Angle (IMA), Distal Metatarsal Articular Angle (DMAA)) and clinical outcomes (American Orthopaedic Foot & Ankle Society Score (AOFAS), Visual Analog Scale (VAS), Manchester-Oxford Foot Questionnaire (MOXFQ)). Secondary outcomes included operative details, complications, and revision surgery rates. Five studies met inclusion criteria: two clinical (n = 153 patients, 162 feet) and three biomechanical studies. Clinical studies showed comparable radiographic correction and patient-reported outcomes between fixation methods. Single screw fixation demonstrated significantly shorter operative time and reduced fluoroscopy exposure. Hardware-related complications requiring removal were higher in two-screw groups (32% vs. 3% in one study; 1.9% vs. 0% in another). Biomechanical studies revealed that single screw fixation may provide insufficient rotational stability, while two-screw configurations demonstrated improved construct stability. Current evidence suggests that single screw fixation may reduce radiation exposure, surgical time, and hardware removal rates, but offers reduced biomechanical stability compared to a two-screw construct in patients undergoing minimally invasive hallux valgus surgery. However, the high risk of bias, limited comparative data, methodological heterogeneity, and relatively short follow-up periods in existing studies preclude definitive conclusions. Current evidence is insufficient to establish definitive recommendations, and fixation strategy should be individualised based on deformity characteristics and patient factors.