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J Wrist Surg 2018; 07(02): 094-100
DOI: 10.1055/s-0038-1637739
Special Review: Scaphoid Nonunion Treatment
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Current Management of Scaphoid Nonunion Based on the Biomechanical Study

Kunihiro Oka
1   Health and Counseling Center, Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Osaka, Japan
,
Hisao Moritomo
2   Department of Physical Therapy, Osaka Yukioka College of Health Science, Osaka, Japan
› Author Affiliations
Funding The authors were supported by JSPS KAKENHI (grant number JP 15K10442).
Further Information

Publication History

21 December 2017

08 February 2018

Publication Date:
14 March 2018 (online)

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Abstract

Scaphoid nonunion causes abnormal wrist kinematics and typically leads to carpal collapse and subsequent degenerative arthritis of the wrist. However, the natural history, including carpal collapse and degenerative arthritis of scaphoid nonunion, may vary at different fracture locations. This article reviews recent biomechanical studies related to the natural history of scaphoid nonunion. In the distal-type fractures (type B2 in Herbert classification), where the fracture located distal to the scaphoid apex, the proximal scaphoid fragment and lunate, which are connected through the dorsal scapholunate interosseous ligament (DSLIL) and dorsal intercarpal ligament (DIC), extend together, and the distal fragment of the scaphoid flexes individually. Therefore, untreated type B2 fractures normally show the humpback deformity, resulting in dorsal intercalated segment instability deformity relatively earlier after the injury. In the proximal-type fractures (type B1), where the fracture is located proximal to the scaphoid apex, the connection between the distal fragment and lunate is preserved through the DSLIL and DIC so that the scaphoid–lunate complex remains stable and the carpal collapse is less severe than that in distal-type fractures. The fracture location relative to the apex of the dorsal scaphoid ridge is a reliable landmark in the determination of the natural history of scaphoid nonunion.

Keywords

scaphoid nonunion - natural history - carpal collapse - three-dimensional analysis