Identification of overlengthening after replacement of the radial head with a bipolar prosthesis

TY - JOUR

T1 - Identification of overlengthening after replacement of the radial head with a bipolar prosthesis

AU - Wegmann, K

AU - Lamsfuss, J

AU - Ries, C

AU - Neiss, W F

AU - Franklin, J

AU - Müller, L P

AU - Burkhart, K J

PY - 2015/12

Y1 - 2015/12

N2 - INTRODUCTION: Overlengthening of the radial column leads to insufficient functionality and increased capitellar wear. Methods to detect or prevent overlengthening have been described for monopolar prostheses. The aim of this study was to evaluate whether one such method described by Athwal et al. is also applicable for a bipolar prosthesis.MATERIALS AND METHODS: The radial heads of six fresh frozen upper extremities were resected. A bipolar radial head prosthesis was implanted in each, and the effects of sequential overlengthening on the alignment of the radiocapitellar and ulnohumeral joint line were recorded by fluoroscopic images. Digital image analysis and estimation of overlengthening followed according to the method described by Athwal et al.RESULTS: Statistical analysis of the estimated and actual differences between the native state and bipolar replacement of the radial head with stepwise overlengthening of 1.5, 3, 4.5, and 6 mm showed a specificity of 86 % but consistently underestimated the amount of overlengthening with a sensitivity of only 61 %.DISCUSSION: The method described by Athwal et al. for the identification of overlengthening by a monopolar prosthesis was not found to be reliable for ruling out or quantifying overlengthening of the tested bipolar prosthesis. However, the use of the method to detect (rule in) overlengthening may be acceptable in certain circumstances. A reliable method for postoperative quantification of overlengthening by bipolar prostheses has still to be found.

AB - INTRODUCTION: Overlengthening of the radial column leads to insufficient functionality and increased capitellar wear. Methods to detect or prevent overlengthening have been described for monopolar prostheses. The aim of this study was to evaluate whether one such method described by Athwal et al. is also applicable for a bipolar prosthesis.MATERIALS AND METHODS: The radial heads of six fresh frozen upper extremities were resected. A bipolar radial head prosthesis was implanted in each, and the effects of sequential overlengthening on the alignment of the radiocapitellar and ulnohumeral joint line were recorded by fluoroscopic images. Digital image analysis and estimation of overlengthening followed according to the method described by Athwal et al.RESULTS: Statistical analysis of the estimated and actual differences between the native state and bipolar replacement of the radial head with stepwise overlengthening of 1.5, 3, 4.5, and 6 mm showed a specificity of 86 % but consistently underestimated the amount of overlengthening with a sensitivity of only 61 %.DISCUSSION: The method described by Athwal et al. for the identification of overlengthening by a monopolar prosthesis was not found to be reliable for ruling out or quantifying overlengthening of the tested bipolar prosthesis. However, the use of the method to detect (rule in) overlengthening may be acceptable in certain circumstances. A reliable method for postoperative quantification of overlengthening by bipolar prostheses has still to be found.

KW - Aged, 80 and over

KW - Cadaver

KW - Elbow Joint/injuries

KW - Elbow Prosthesis/adverse effects

KW - Female

KW - Follow-Up Studies

KW - Humans

KW - Intra-Articular Fractures/diagnosis

KW - Male

KW - Postoperative Complications/diagnosis

KW - Prosthesis Design

KW - Prosthesis Implantation/adverse effects

KW - Radius/injuries

KW - Radius Fractures/diagnosis

KW - Replantation

U2 - 10.1007/s00402-015-2333-4

DO - 10.1007/s00402-015-2333-4

M3 - SCORING: Journal article

C2 - 26450831

VL - 135

SP - 1669

EP - 1674

JO - ARCH ORTHOP TRAUM SU

JF - ARCH ORTHOP TRAUM SU

SN - 0936-8051

IS - 12

ER -