Motorised Intramedullary Bone Transport: A Scoping Review

Segmental bone defects present a significant reconstructive challenge in orthopaedic surgery and are traditionally reconstructed using external fixation. The advent of motorised intramedullary bone transport nails (BTNs) aims to mitigate complications associated with external fixation. Despite the theoretical advantages, the clinical efficacy and complication profile of BTNs remain unclear. This scoping review evaluates the current literature on the use of BTNs in segmental bone defect reconstruction.

A search of PubMed, Google Scholar, and Cochrane Library databases was conducted following the PRISMA-ScR guidelines. Studies published between 2010 and 2024 that reported on motorised BTNs were included. Data extraction focused on patient demographics, defect characteristics, treatment strategies, complications, consolidation indices, and functional outcomes. Due to study heterogeneity, results were synthesised descriptively.

Fifteen studies were included, comprising three retrospective cohorts, seven case series, and five case reports, totalling 61 patients. Most defects occurred in the femur (60.7%), with trauma (39.3%) as the most common aetiology. The mean defect size was 7.1 cm (range: 0.5-17 cm). The overall union rate was 92.3%, with a mean bone healing index (BHI) of 51.36 days/cm. A total complication incidence of 106.6% was reported, reflecting multiple complications in some patients, with device-related failures (22%), joint contractures (14%), and delayed union (9%) as common occurrences. While BTNs eliminate external fixation-associated morbidity, they introduce unique challenges such as mechanical failures and prolonged periods of non-weight-bearing. Patient-reported outcomes (PROMs) were rarely assessed, with only two studies reporting functional scores.

Motorised intramedullary bone transport offers a promising alternative to external fixation, particularly for femoral defects. However, BTNs introduce device-specific complications and remain costly and technically demanding. Current evidence is limited to small case series with heterogeneous methodologies, precluding definitive conclusions on superiority over external fixation. Future research should focus on multi-centre comparative studies with standardised outcome measures to establish the optimal role of BTNs in limb reconstruction.