Spinal disassociation masquerading as iatrogenic listhesis above a previous fusion.
METHODS
A case of remarkable instability adjacent to an L5-S1 fusion is reported.


OBJECTIVE
The objective of this study was to review a case of marked instability adjacent to a prior fusion. Diagnostic workup and surgical management options are discussed.


BACKGROUND
Junctional degeneration above or below the levels of a spinal fusion may be associated with instability. We present an unusual case of instability whose severity was only apparent when the patient was under general anesthesia.


METHODS
A 52-year-old man with a history of prior L5-S1 fusion presented with severe back pain and lower extremity weakness. Workup including multiple imaging methods revealed junctional degeneration and a Grade I spondylolisthesis at L4-L5 with minimal translation on dynamic imaging. Operative intervention was planned.


RESULTS
Intraoperative imaging revealed marked distraction at the L4-L5 disc space not apparent on preoperative dynamic films. The surgical approach was modified accordingly.


CONCLUSIONS
Adjacent segment degeneration next to a prior lumbar fusion may be associated with extreme instability. Treatment may require complex stabilization.
Department of Orthopaedics, Rothman Institute, Thomas Jefferson University Hospital, Philadelphia, PA, USA.
Arjun
A
Saxena
Eli M
EM
Baron
D Greg
DG
Anderson
Alan S
AS
Hilibrand
James S
JS
Harrop
Alexander R
AR
Vaccaro
D003937:Diagnosis, Differential; D006801:Humans; D007049:Iatrogenic Disease; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D011859:Radiography; D013123:Spinal Fusion / Q000009:adverse effects; D013130:Spinal Stenosis / Q000175:diagnosis* / Q000601:surgery