No Difference Between Intramedullary Kirschner-Wires and Titanium Elastic Nails in Treating Pediatric Femur Fractures: Results From a Randomized Clinical Trial in Dar Es Salaam, Tanzania.

BACKGROUND

Femur fractures are a common cause of disability of children in low-and middle-income countries (LMICs). The introduction of flexible intramedullary nails improved the care of children with diaphyseal femoral fractures. Application of intramedullary nails is challenging in resource-limited settings due to implant cost and availability. Intramedullary Kirschner-wire (K-wire) fixation has been proposed as a low-cost alternative option for pediatric femur fractures. This study examines the non-inferiority of intramedullary K-wire to titanium elastic nail (TEN) for diaphyseal pediatric femur fractures.

METHODS

A randomized clinical trial was performed at a tertiary orthopaedic center in Dar es Salaam, Tanzania. Children (5-14 years) with acute diaphyseal femur fractures were randomly assigned to intramedullary K-wire or TEN fixation. The primary outcome was malunion. Secondary outcomes included modified RUST score (mRUST), PedsQL questionnaire, squat depth, and complications.

RESULTS

Of the 61 patients (33 K-wire, 28 TEN), 83% completed 1-year follow-up. This trial enrolled 61 of 160 planned patients (38% of target enrollment) and was therefore underpowered to establish non-inferiority. There were 5 cases of malunion (3 K-wire, 2 TEN; Risk difference 0.034, 95% CI -0.122-0.191, P = .52). No statistically significant difference was detected in mRUST score at 1-year follow-up (K-wire 16.00 vs. TEN 16.00, P-value = .38). Reoperation was required in 3 K-wire patients (9.1%) versus 0 TEN patients (P = .145). There were no statistically significant differences in PedsQL, squat depth, or clinical complications between groups.

CONCLUSIONS

This study is the first prospective RCT assessing intramedullary K-wire versus TEN for the treatment of pediatric femoral shaft fractures in Africa. No statistically significant difference was detected in malunion, radiographic union, functional outcomes, or patient/parent reported outcome measures between groups. Although this study did not achieve its target sample size and therefore cannot formally claim non-inferiority, non-inferiority was not established. A trend toward higher reoperation rates in the K-wire group (9% vs. 0%) warrants evaluation in adequately powered future trials. Intramedullary K-wires may be considered as an alternative implant when TEN is unavailable, but the current evidence is insufficient to support a recommendation of equivalence.

KEY CONCEPTS: (1)Intramedullary K-wire fixation showed no statistically significant difference in rates of malunion, radiographic union, and functional outcomes compared to titanium elastic nails for pediatric diaphyseal femur fractures in a low-resource setting; however, the study was underpowered and non-inferiority was not formally established.(2)Two independent randomized controlled trials, conducted on two different continents, have found no statistically significant difference in outcomes between intramedullary K-wires and titanium elastic nails for pediatric femoral shaft fractures, at a fraction of the implant cost, supporting their role as a viable alternative in resource-limited settings.(3)Although this study did not achieve its target sample size and therefore cannot formally claim non-inferiority, the results are consistent with K-wires being a safe and effective alternative to titanium elastic nails.(4)The substantial cost advantage of K-wires supports their use as a strategy to expand access to operative fixation in low- and middle-income countries.(5)Patient-reported and functional outcomes, including PedsQL quality-of-life scores and squat depth, showed no statistically significant difference between K-wire and titanium elastic nail groups at one-year follow-up; however, the study was underpowered, and these findings should be interpreted accordingly.

LEVEL OF EVIDENCE: Level I.