Validity of the non-union scoring system in management of long bone fracture non-union. A prospective study

To validate the Non-union Scoring System by applying the score, prospectively, on long bone non-union cases and evaluate the results of the treatment according to the score.

In order to assess treatment efficacy on non-union treatment, the NUSS was used in a series of patients diagnosed with femoral and tibial non-union. We included both septic and aseptic non-union and excluded skeletally immature patients, patients with autoimmune diseases, neoplasia and patients under immunosuppressive therapy. The patients were followed up for maximum of 30 months.

The NUSS was applied prospectively to 60 cases of fracture non-union. The outcomes demonstrated that most patients across different NUSS treatment groups achieved successful healing, with group 1 reporting 88.9%, group 2 achieving 80%, and group 3 achieving 81.5% union rates. The mean time for clinical and radiographic healing varied by group, with longer recovery times seen in more severe cases. Three patients who underwent amputation were not included in the final union assessment. Six patients were excluded from the study due to what was termed a "score-clinical mismatch," where intraoperative findings indicated a need for more aggressive treatment than the NUSS had suggested.

The NUSS is a reliable tool for managing fracture non-union, but it may underestimate treatment needs in some cases. Incorporating intraoperative assessment into the protocol can help prevent undertreatment, and improve the accuracy of the NUSS in guiding treatment decisions. Retrospectively registered under Trial Registration Number NCT07207447 on 3/10/2025.