Buried Versus Exposed K-Wires in Hand Fracture Fixation: A Meta-Analysis of Outcomes

TL;DR

Burying K-wires in hand fracture surgery reduces infection risk but increases costs and need for additional procedures, while exposed wires are more cost-effective but carry higher infection risk.

Contribution

This study provides a meta-analysis comparing outcomes of buried versus exposed K-wires in hand fractures, clarifying trade-offs between infection rates and procedural costs.

Findings

Buried K-wires significantly reduce pin site infections compared to exposed wires.

Exposed K-wires are more cost-effective as they avoid additional surgical procedures.

Both techniques show similar rates of fracture union and major complications.

Abstract

A key decision in orthopaedic surgery is whether to leave Kirschner wires (K-wires) protruding through the skin or to cut and bury them subcutaneously. This choice may affect infection risk, need for secondary procedures, patient comfort and cost. However, the evidence comparing buried versus exposed K-wires has been conflicting, leaving surgeons with no clear consensus. We performed a meta-analysis to quantitatively compare outcomes of buried versus exposed K-wires in phalangeal, metacarpal and distal radius fractures.

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and searched PubMed, Embase, Scopus and Cochrane CENTRAL (up to September 2025) for comparative studies of buried versus exposed K-wire fixation. Eligible studies included randomised controlled trials (RCTs) and observational cohorts in adult or paediatric hand/wrist fractures. Two reviewers independently extracted data on study design, patient characteristics and outcomes. The primary outcome was pin site infection. Secondary outcomes included K-wire removal in the operating theatre, unplanned early pin removal (before union), other complications (e.g., wire migration and fixation failure), fracture union and costs. We assessed bias (Cochrane Risk of Bias 2.0 tool and Newcastle-Ottawa Scale (NOS)) and pooled dichotomous outcomes as odds ratios (OR) with 95% confidence intervals (CIs) using a random effects model. Heterogeneity was quantified with I².

Seven comparative studies (N = 1,446 patients) met the inclusion criteria. In the pooled analysis of six studies (1,394 fractures), exposed K-wires had a significantly higher pin site infection rate than buried wires (OR: 2.15, 95% CI: 1.43-3.21; p = 0.0001). By contrast, virtually all K-wire removal procedures for buried wires required a return to theatre, whereas exposed wires were almost always removed in the clinic. The pooled OR for removal under anaesthesia was about 0.02 (buried versus exposed), indicating that nearly all patients needing a removal in the operating room (OR) had buried wires. Early unplanned pin removal was uncommon and did not differ significantly between groups (pooled OR: ~2.07, 95% CI: 0.93-4.62, p = 0.07). Non-union and malunion were rare overall, with no clear differences by K-wire technique. Other complications (wire migration or irritation) were few; one systematic review noted that buried wires sometimes erode through skin as swelling subsides. Cost analyses consistently showed higher resource use for buried wires. Thus, exposed K-wires were far more cost-effective, largely because they avoid a routine second operation.

Burying K-wires significantly reduces superficial pin site infections compared to leaving them exposed, but at the expense of additional anaesthetic procedures and higher cost. Union rates and complication rates are similar between the techniques. Surgeons should weigh the infection prophylaxis benefit of buried wires against the inconvenience and expense of additional surgery. In patients at high infection risk, burying wires may be justified; otherwise, leaving wires exposed (with pin care) is a safe and cost-efficient option. Future randomised trials focusing on patient-centred outcomes are needed to refine guidelines for K-wire management.

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