A Comparison of the Device-Related Complications of Intramedullary Lengthening Nails Using a New Classification System.

The purpose of this study was to understand the pros and cons of the lengthening nails which have their own mechanical mechanism; we propose a classification for "device-related complications" arising from mechanical properties of the nail itself. From March 2010 to March 2014, 115 segments of lower limb lengthening were performed using intramedullary lengthening nails (35 ISKD, 34 PRECICE1, and 46 PRECICE2). Device-related complications were sorted into three categories according to a new classification: distraction control-related (type I), stability related (type II), and other device-related (type III); these were subdivided using Paley's concept of problems (a), obstacles (b), and sequel (c). Most common complications were distraction mechanism issues (type I) in ISKD and mechanical strength related ones (type II) in PRECICE1 and PRECICE2. Sixty percent (21/35) of ISKD had device-related problems. In PRECICE1 group, 8.8% (3/34) had device-related problems, and 8.8% (3/34) showed device-related obstacle. In PRECICE2, forty-four percent (20/46) had device-related problems. In conclusion, a new classification showed more clearly the differences of mechanical characteristics of different nails. The most essential thing of future lengthening nail development is minimizing the types I and II complications. Further study is necessary to compare the mechanical strength and stability of lengthening nails.