Evaluation of Arm Length as a New Upper Limb Anthropometric Method for Preoperative Estimation of Tibial Intramedullary Nail Length

AIM AND OBJECTIVE: To assess the use of arm length (AL) for the estimation of tibial nail length preoperatively and compare its accuracy to various established upper and lower limb anthropometric parameters. MATERIAL AND METHODS: This prospective study of 54 patients assessed upper limb parameters as a possible alternative for intraoperatively measured tibial nail length. The anthropometric parameters measured independently by two observers were AL, olecranon to fifth metacarpal head (OMD), tibial tuberosity to medial malleolus (TT-MM), tibial tuberosity to medial malleolus minus 20 mm (TT-MM-20 mm) and knee joint line to medial malleolus minus 40 mm (KJL-MM-40) and compared to final nail size used intraoperatively. Two observers were used. Bland-Altman plots were constructed to assess the limits of agreement to intraoperative estimates of optimum nail length. A repeatability assessment was also assessed by both observers. RESULTS: None of the anthropometric parameters showed limits of agreement within ±10 mm of nail length. AL showed the least average difference and best limits of agreement among all the anthropometric parameters. Among the lower limb parameters, the KJL-MM showed the least average difference but poorer limits of agreement to nail length. The OMD measurement showed a greater average difference than the AL indicating it is a poorer upper limb parameter for predicting nail length. CONCLUSION: AL as measured between the angle of the acromion to the lateral epicondyle can be used as a preoperative upper limb anthropometric estimate of nail length to one nail size of the optimum length. Further studies with a larger sample size may reduce the confidence intervals and help justify its wider use. HOW TO CITE THIS ARTICLE: Sharma A, Sinha S, Gupta S, et al. Evaluation of Arm Length as a New Upper Limb Anthropometric Method for Preoperative Estimation of Tibial Intramedullary Nail Length. Strategies Trauma Limb Reconstr 2021;16(1):20–26.