Outcomes of Internal, External, and Hybrid Fixation in Hindfoot Charcot Neuroarthropathy: A Descriptive Systematic Review and Single-Arm Meta-analysis of Observational Studies.

BACKGROUND

Charcot neuroarthropathy (CN) of the hindfoot often requires internal fixation (IF), external fixation (EF), or hybrid constructs. This descriptive systematic review and single-arm meta-analysis summarizes outcomes of these strategies, focusing on amputation, fusion, ambulation, and complications.

METHODS

Following PRISMA guidelines, 30 studies with 957 patients undergoing hindfoot or ankle reconstruction were included. A single-arm meta-analysis assessed amputation and fusion rates; qualitative analysis examined ambulation, infection, ulceration, hardware failure, and revision. Heterogeneity was quantified with I² and τ².

RESULTS

Under random effects models, the overall amputation rate across all fixation methods was 4.76% (95% CI: 1.79%-8.62%), and the pooled fusion rate was 80.8% (95% CI: 73.6%-87.1%). By fixation type, EF cohorts showed numerically higher amputation rates (8.11%; 95% CI: 2.32%-15.91%) than IF (4.53%; 95% CI: 0.98%-9.69%) and hybrid fixation (2.94%; 95% CI: 0.00%-12.63%). EF demonstrated a lower fusion rate (68.2%; 95% CI: 55.8%-79.6%) than IF (84.9%; 95% CI: 75.8%-92.5%) and hybrid constructs (85.8%; 95% CI: 75.1%-94.4%). Return to ambulation was comparable between fixation strategies. IF cohorts reported fewer soft tissue complications but higher hardware failure (24.1%) and revision (21.9%) rates, whereas EF cohorts experienced frequent pin tract problems (24.0%). Hybrid constructs showed higher infection (23.2%), hardware complications (33.3%), and revision (18.8%). Substantial between-study heterogeneity and likely selection bias were present.

CONCLUSION

Across 30 observational studies (957 patients; 970 feet), pooled single-arm estimates indicate that limb salvage and osseous fusion were achieved in most cases across internal, external, and hybrid fixation. External fixation was typically selected for infected or more complex reconstructions and was associated with higher amputation and lower fusion proportions, whereas internal and hybrid constructs showed higher fusion with more hardware-related reoperations. Given substantial heterogeneity and confounding by indication, these patterns should be viewed as descriptive rather than comparative; they do not establish indications or superiority.