J Wrist Surg 2021; 10(03): 208-215
DOI: 10.1055/s-0040-1722334
Scientific Article

Biomechanics of the Distal Radioulnar Joint During In Vivo Forearm Pronosupination

1   Center for Biomedical Engineering, Brown University, Providence, Rhode Island
,
2   Department of Orthopedics, The Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
,
2   Department of Orthopedics, The Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
,
2   Department of Orthopedics, The Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
,
2   Department of Orthopedics, The Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
3   Division of Hand, Upper Extremity & Microvascular Surgery, Department of Orthopaedics, The Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
,
4   Hand and Upper Extremity Center, Hospital for Special Surgery, New York, New York
5   Department of Orthopaedic Surgery, Weill Medical College of Cornell University, New York, New York
,
1   Center for Biomedical Engineering, Brown University, Providence, Rhode Island
2   Department of Orthopedics, The Warren Alpert Medical School of Brown University and Rhode Island Hospital, Providence, Rhode Island
› Author Affiliations
Funding J.J.C reports grants from National Institute of General Medical Sciences (P30GM122732), and from the American Foundation for Surgery of the Hand (AFSH) during the conduct of the study.

Abstract

Background Ulnar variance (UV) and center of rotation (COR) location at the level of the distal radioulnar joint (DRUJ) change with forearm rotation. Nevertheless, these parameters have not been assessed dynamically during active in vivo pronosupination. This assessment could help us to improve our diagnosis and treatment strategies.

Questions/purposes We sought to (1) mathematically model the UV change, and (2) determine the dynamic COR's location during active pronosupination.

Methods We used biplanar videoradiography to study DRUJ during in vivo pronation and supination in nine healthy subjects. UV was defined as the proximal-distal distance of ulnar fovea with respect to the radial sigmoid notch, and COR was calculated using helical axis of motion parameters. The continuous change of UV was evaluated using a generalized linear regression model.

Results A second-degree polynomial with R 2 of 0.85 was able to model the UV changes. Maximum negative UV occurred at 38.0 degrees supination and maximum positive UV occurred at maximum pronation. At maximum pronation, the COR was located 0.5 ± 1.8 mm ulnarly and 0.6 ± 0.8 mm volarly from the center of the ulnar fovea, while at maximum supination, the COR was located 0.2 ± 0.6 mm radially and 2.0 ± 0.5 mm volarly.

Conclusion Changes in UV and volar translation of the COR are nonlinear at the DRUJ during pronosupination.

Clinical Relevance Understanding the dynamic nature of UV as a function of pronosupination can help guide accurate evaluation and treatment of wrist pathology where the UV is an important consideration. The dynamic behavior of COR might be useful in designing DRUJ replacement implants to match the anatomical motion.



Publication History

Received: 28 August 2020

Accepted: 12 November 2020

Article published online:
04 February 2021

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