Bunion (Hallux Valgus) Surgery: What New Evidence Tells Us About Screw Fixation

Bunion pain can turn a simple stroll into a careful calculation. For many patients, Bunion (Hallux Valgus) Surgery—especially minimally invasive approaches—offers a way back to comfortable, confident walking. But here’s a question we’re often asked at clinic: which screw configuration actually gives the most stable fixation during minimally invasive bunion correction? A recent finite element analysis provides timely, practical answers that can inform surgical planning and patient expectations.

Key Takeaway: The Most Stable Screw Configuration in Minimally Invasive HV Surgery

A 2025 study in Foot & Ankle Surgery compared five screw configurations for minimally invasive hallux valgus correction using high-fidelity finite element analysis (FEA). The standout finding? Using two screws—one bicortical and one intramedullary—resulted in the least osteotomy displacement and the lowest stress on both bone and implants under loading.

Reference: PubMed: 39261184 | DOI: 10.1016/j.fas.2024.09.001

What the Study Did, in Plain English

Researchers built an anatomically accurate model from a CT scan of a woman with moderate hallux valgus. They virtually “tested” five different screw setups commonly used in minimally invasive bunion surgery. The team measured:

• Osteotomy displacement (how much the cut bone moved under load)
• Maximum and minimum principal stresses (tension and compression in the bone)
• von Mises stress (a combined stress measure relevant to implant performance)

The combination of one bicortical screw (engaging both cortices for strong purchase) plus one intramedullary screw (aligned within the canal to share load) outperformed single-screw constructs and other two-screw variants.

Why This Matters for Patients Considering Bunion Surgery

When we plan minimally invasive Bunion (Hallux Valgus) Surgery, our goals are stability, alignment, and a smooth recovery. Construct stability is central to all three. Better stability typically supports:

• More reliable alignment maintenance
• Lower implant stress and potential hardware-related complications
• Controlled, confident progression of weight-bearing guided by your surgeon

While every foot is unique, having robust biomechanical data helps us tailor decisions rather than rely solely on convention.

Minimally Invasive vs Open Bunion Surgery: Where Does Fixation Fit In?

Minimally invasive techniques use small incisions to correct deformity, often resulting in reduced soft-tissue trauma and potentially faster functional recovery. Fixation choice—how we secure the bone after cutting and shifting it—must complement the technique. The study’s FEA indicates a two-screw strategy (bicortical plus intramedullary) may be the sweet spot for moderate deformities in minimally invasive procedures.

At-a-Glance: Optimal Screw Strategy for Moderate Hallux Valgus

1. Use two screws for enhanced stability.
2. Combine one bicortical screw with one intramedullary screw.
3. Aim to minimise osteotomy displacement and reduce stress on bone and implants.

Level of Evidence: III (finite element analysis), which is strong for biomechanics but should be integrated with clinical outcomes and surgeon expertise.

What Does “Bicortical” and “Intramedullary” Mean?

– Bicortical: The screw traverses both the near and far cortex of the bone, anchoring firmly across the bone’s outer layers.

– Intramedullary: The screw sits within the canal of the bone, helping align and share load along the bone’s mechanical axis.

In combination, they appear to balance grip and load-sharing—lowering overall stress and motion at the osteotomy.

How We Translate This Evidence Into Practice

In clinic, we consider deformity severity, bone quality, soft-tissue balance, and patient activity levels. This FEA supports a two-screw construct for moderate hallux valgus in minimally invasive surgery, which aligns with our experience: stability you can feel under the fluoroscope and see on follow-up imaging.

Concise Answers to Common Questions

Is two-screw fixation always better? Not always. It performed best in this FEA for moderate deformity, but patient-specific factors can sway the decision.

Will this change my recovery? Greater construct stability can support predictable rehabilitation, but protocols remain individualised.

Does more hardware mean more problems? Not necessarily. Lower stress across implants may reduce hardware-related issues in suitable cases.

Evidence in Context: What Else Do We Know?

Hallux valgus affects up to 23% of adults and over 35% of older adults, with higher prevalence in women (likely a blend of biomechanics and footwear factors). Large epidemiological summaries continue to report functional limitations and footwear difficulties as key drivers for seeking surgery. For prevalence data, see Nix et al., J Foot Ankle Res (2010) and subsequent population updates; a widely cited review is available via PubMed. While older, it frames the scale of the problem; newer clinical series increasingly focus on outcomes and patient-reported measures.

The current FEA adds a biomechanical layer—how constructs behave before we even get to clinical endpoints. That’s valuable, but we still pair it with real-world outcomes when advising patients.

Study Details and Citation

Foot Ankle Surg. 2025 Feb;31(2):160-169. Epub 2024 Sep 10. Title: Finite element comparison of screw configurations for minimally invasive hallux valgus osteotomy. Conclusion: one bicortical plus one intramedullary screw provided the lowest osteotomy displacement and stress across bone and implants under both loading conditions. Level of Evidence: III. PMID: 39261184 | DOI: 10.1016/j.fas.2024.09.001

Our Expert View

From a surgical standpoint, the “bicortical plus intramedullary” pairing makes mechanical sense—think seatbelt plus airbag. One secures across the outer shell; the other supports from within. We would still individualise fixation based on bone stock, osteotomy type, and the degree of correction, but this analysis nudges the needle toward a consistent two-screw strategy in moderate cases.

Bottom Line for Patients Considering Bunion (Hallux Valgus) Surgery

If you’re exploring minimally invasive bunion correction, ask about fixation strategy. Current biomechanical evidence suggests that two screws—one bicortical and one intramedullary—offer superior stability for moderate deformities. As always, the best plan balances evidence, your anatomy, and your goals.

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