High Reliability of a Scoring System for Implant Position in Undisplaced Femoral Neck Fractures

TY - JOUR

T1 - High Reliability of a Scoring System for Implant Position in Undisplaced Femoral Neck Fractures

AU - Viberg, Bjarke

AU - Bartholin, Marie-Louise L

AU - Weber, Kolja

AU - Bech, Rune D

AU - Palm, Henrik

AU - Schultz-Larsen, Morten

PY - 2016/8/1

Y1 - 2016/8/1

N2 - OBJECTIVES: The aim of this study was to evaluate the intrarater and interrater reliability of a scoring system for internal fixation (SIFA) in undisplaced femoral neck fractures (FNF).DESIGN: A reproducibility study with a historical consecutive cohort.SETTING: The patients were all treated at a level one trauma hospital.PATIENTS/PARTICIPANTS: A cohort of patients with FNF, treated with 2 parallel implants, was retrieved using a local county register, and the cohort was assessed for undisplaced FNF until the desired sample size was reached. One hundred two patients had their x-ray images reviewed 2 times with a minimum 14 days interval, by 3 raters, all blinded for each other's results, and an independent person analyzed the data with unweighted kappa statistics.MAIN OUTCOME MEASUREMENTS: Implant positions on the first postoperative anterior-posterior and axial radiographs were first visually assessed, then objectively measured according to SIFA, which consists of 5 individual measurements; screw tip distance, screw femoral shaft angle, inferior screw calcar distance, and screw position in the femoral head in the anterior-posterior and axial radiographs.RESULTS: Visually assessed implant position gave intrarater kappa results for the individual components of SIFA at 0.40-0.75 (rater 1), 0.75-0.98 (rater 2), and 0.69-0.83 (rater 3), with interrater kappa results at 0.18-0.80 (combined range). Objectively measured implant position for the individual components of SIFA gave intrarater kappa results at 0.56-1.0 (rater 1), 0.74-0.89 (rater 2), and 0.81-0.94 (rater 3), with interrater kappa results at 0.56-0.85 (combined range). The overall SIFA score has similar higher intrarater and interrater results for the measured (0.51-0.78) compared with the visual assessment (0.13-0.78). The assessment in the axial view of the screw position in femoral head had the largest difference of acceptable positioning, when comparing visual assessment with the measured.CONCLUSIONS: The SIFA demonstrates substantial intrarater and interrater reliability (kappa 0.51-0.78), when raters make measurements of radiographs, but lower reliability (kappa 0.13-0.78) when raters visually assess the radiographs without measuring. The SIFA should be assessed on a large cohort, for correlation with clinical evaluation.

AB - OBJECTIVES: The aim of this study was to evaluate the intrarater and interrater reliability of a scoring system for internal fixation (SIFA) in undisplaced femoral neck fractures (FNF).DESIGN: A reproducibility study with a historical consecutive cohort.SETTING: The patients were all treated at a level one trauma hospital.PATIENTS/PARTICIPANTS: A cohort of patients with FNF, treated with 2 parallel implants, was retrieved using a local county register, and the cohort was assessed for undisplaced FNF until the desired sample size was reached. One hundred two patients had their x-ray images reviewed 2 times with a minimum 14 days interval, by 3 raters, all blinded for each other's results, and an independent person analyzed the data with unweighted kappa statistics.MAIN OUTCOME MEASUREMENTS: Implant positions on the first postoperative anterior-posterior and axial radiographs were first visually assessed, then objectively measured according to SIFA, which consists of 5 individual measurements; screw tip distance, screw femoral shaft angle, inferior screw calcar distance, and screw position in the femoral head in the anterior-posterior and axial radiographs.RESULTS: Visually assessed implant position gave intrarater kappa results for the individual components of SIFA at 0.40-0.75 (rater 1), 0.75-0.98 (rater 2), and 0.69-0.83 (rater 3), with interrater kappa results at 0.18-0.80 (combined range). Objectively measured implant position for the individual components of SIFA gave intrarater kappa results at 0.56-1.0 (rater 1), 0.74-0.89 (rater 2), and 0.81-0.94 (rater 3), with interrater kappa results at 0.56-0.85 (combined range). The overall SIFA score has similar higher intrarater and interrater results for the measured (0.51-0.78) compared with the visual assessment (0.13-0.78). The assessment in the axial view of the screw position in femoral head had the largest difference of acceptable positioning, when comparing visual assessment with the measured.CONCLUSIONS: The SIFA demonstrates substantial intrarater and interrater reliability (kappa 0.51-0.78), when raters make measurements of radiographs, but lower reliability (kappa 0.13-0.78) when raters visually assess the radiographs without measuring. The SIFA should be assessed on a large cohort, for correlation with clinical evaluation.

KW - Journal Article

U2 - 10.1097/BOT.0000000000000590

DO - 10.1097/BOT.0000000000000590

M3 - Journal article

C2 - 27129128

SN - 0890-5339

VL - 30

SP - 432

EP - 436

JO - Journal of Orthopaedic Trauma

JF - Journal of Orthopaedic Trauma

IS - 8

ER -