Open Access Research article

Unexpected angular or rotational deformity after corrective osteotomy

Seung Yeol Lee2, Jiwon Jeong3, Kyungho Lee3, Chin Youb Chung1, Kyoung Min Lee1, Soon-Sun Kwon4, Young Choi1, Tae Gyun Kim5, Jeong Ik Lee1, Jehee Lee3* and Moon Seok Park1*

Author Affiliations

1 Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Kyungki, Korea

2 Department of Orthopaedic Surgery, Myongji hospital, Kyungki, Korea

3 School of Computer Science and Engineering, Seoul National University, Seoul, Korea

4 Biomedical Research Institute, Seoul National University Bundang Hospital, Kyungki, Korea

5 Department of Orthopaedic Surgery, Konyang University Hospital, Daejon, Korea

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BMC Musculoskeletal Disorders 2014, 15:175  doi:10.1186/1471-2474-15-175

Published: 24 May 2014



Codman’s paradox reveals a misunderstanding of geometry in orthopedic practice. Physicians often encounter situations that cannot be understood intuitively during orthopedic interventions such as corrective osteotomy. Occasionally, unexpected angular or rotational deformity occurs during surgery.

This study aimed to draw the attention of orthopedic surgeons toward the concepts of orientation and rotation and demonstrate the potential for unexpected deformity after orthopedic interventions. This study focused on three situations: shoulder arthrodesis, femoral varization derotational osteotomy, and femoral derotation osteotomy.


First, a shoulder model was generated to calculate unexpected rotational deformity to demonstrate Codman’s paradox. Second, femoral varization derotational osteotomy was simulated using a cylinder model. Third, a reconstructed femoral model was used to calculate unexpected angular or rotational deformity during femoral derotation osteotomy.


Unexpected external rotation was found after forward elevation and abduction of the shoulder joint. In the varization and derotation model, closed-wedge osteotomy and additional derotation resulted in an unexpected extension and valgus deformity, namely, under-correction of coxa valga. After femoral derotational osteotomy, varization and extension of the distal fragment occurred, although the extension was negligible.


Surgeons should be aware of unexpected angular deformity after surgical procedure involving bony areas. The degree of deformity differs depending on the context of the surgical procedure. However, this study reveals that notable deformities can be expected during orthopedic procedures such as femoral varization derotational osteotomy.

Codman’s paradox; Unexpected angulation; Femoral varization derotational osteotomy; Femoral derotation osteotomy