Clinical Outcomes and Complications of the Surgical Implant Generation Network (SIGN) Intramedullary Nail: A Systematic Review and Meta-analysis.

OBJECTIVES: This study is a systematic review and meta-analysis of the clinical outcomes and pooled complication rate of femoral, tibial, and humeral fracture fixation using SIGN nails. We aimed to compare the pooled rate of adverse events based on the country of study origin, acute versus delayed fracture fixation, and length of follow up.

METHODS: We searched PubMed/MEDLINE/Cochrane databases from 2000-2016 for English language studies. There was substantial heterogeneity among included studies. Therefore, we employed sub-group analysis of varying adverse events and removal of potential outlier studies based on the 'remove one' sensitivity analysis, to address the heterogeneity across studies. A funnel plot was drawn and inspected visually to assess publication bias. We reported pooled complication rates for each adverse event with 95% prediction interval (PI).

RESULTS: There were 14 studies with 47,169 cases across 58 different LMICs. The average age was 33 ± 14 years, with 83% male and 17% female. Sixty percent of SIGN nails utilized in these 14 studies were used in femur fracture fixation, 38% in tibial shaft fractures, and the remaining 2% for humeral shaft fractures. Approximately 23% of patients had follow-up data recorded. All studies that measured clinical outcome indicated that >90% achieved full weight-bearing status, favorable range of motion (knee range of motion >90 degrees according to the SIGN database), and radiographic or clinical union depending on the specific variable(s) measured in each study. The overall complication rate was 5.2% (4.4% - 6.4%). Malalignment (>5 degrees angulation in any plane) was the most common complication (7.6%), followed by delayed/non-union (6.9%), infection (5.9%), and hardware failure, (3.2%).

CONCLUSION: Overall, the use of SIGN nails in fixing femoral, tibial, and humeral shaft fractures demonstrates good results with a high rate of return to full weight-bearing and radiographic/clinical union. The most common complications when using the SIGN nail are malalignment, delayed/non-union, infection and hardware failure.

LEVEL OF EVIDENCE: Level-IV meta-analysis.