Clasp-knife deformity

Case contributed by Dr Iqbal Naseem


A young 20 Yrs male presented with backache.

Patient Data

Age: 20
Gender: Male

Radiograph Pelvis showing enlarged downward slanting spinous process of L5 vertebra extending upto S1-S2 level with spina bifida of L5, S1 and S2 vertebrae.

The transverse processes of L5 are spatulated and the right appears to articulate with the sacrum. 

Case Discussion

Enlarged downward projecting spinous process of L5 vertebra extending up to sacral vertebrae with associated bifida defects is known as "Clasp-knife deformity".

It is often the cause of  backache particularly during bending movements and called "Clasp-knife syndrome".

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Case information

rID: 22825
Published: 26th Apr 2013
Last edited: 16th Jul 2018
Inclusion in quiz mode: Included

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