Sunday, April 7, 2013

Cervical Adjacent Level Degeneration, a Case Study


History

A 51-year-old man, who is a former professional lacrosse player status post C3-C7 laminectomy without fusion (10 years prior) and C5-C6 ACDF (5 years prior) for myelopathy, presents with right arm pain (mild to moderate) and severe right triceps weakness (2 out of 5 strength).

Examination

No evidence of myelopathy. Triceps strength 2/5, decreased triceps reflex 0.  Sensory deficit in C7 distribution.  Absent deep tendon reflex right triceps.

Prior Treatment

Prior surgery C3-C7 laminectomy without fusion (10 years prior).  C5-C6 ACDF 5 years prior.
Extensive PT (no improvement).  One C7 selective nerve root block (temporary relief).

Diagnosis

Right C7 herniated disc and C7 palsy

Case Discussion

This case highlights many of the issues that we face with adjacent level degeneration after cervical surgery.  This patient underwent a C3-C7 laminectomy in the past with subsequent C5-C6 ACDF.  The patient exhibits significant and recalcitrant C7 radiculopathy that is affecting his quality of life.  The MRI displays anterior compression cephalad at C4-C5 with some posterior scar or residual ligamentum flavum hypertrophy as well as a significant C6-C7 disc herniation that is commensurate with the C7 radiculopathy that the patient endorses in subjective questioning and objective examination.  Since the patient underwent a prior multilevel laminectomy and decompression, a revision posterior operation (even to perform a C6-C7 foraminotomy) can be fraught with potential complications, including dural tear, nerve root injury and likelihood of residual scar formation post-operatively.  The concept of a fusionless operation at C6-C7 is intriguing; however, with the patient being 50 years of age, the likelihood of his displaying facet arthrosis is significant and a relative contraindication for a disc replacement. (Comparison of magnetic resonance imaging and computed tomography in predicting facet arthrosis in the cervical spine. Lehman RA Jr, Helgeson MD, Keeler KA, Bunmaprasert T, Riew KD. Spine (Phila Pa 1976). 2009 Jan 1;34(1):65-8)
After obtaining pre-operative consultation with ENT to perform a direct laryngoscopy to assess the vocal cords after the previous anterior approach, a good option is to address this pathology from an anterior operation since that is the site of the compression.  Performing a discectomy from a posterior approach in the setting of previous laminectomy may lead to a higher complication rate.  Removal of the plate at C5-C6 and performance of a generous discectomy and foraminotmy with take down of the posterior longitudinal ligament (PLL) allows for adequate excision of the disc fragment and decompression of the posterior osteophytes. The other consideration is to properly evaluate the C4-C5 level to determine if there is a decreased threshold for symptoms at the C6-C7 level because of the compression at C4-C5.  This level could be contributing to the post-operative pain experienced by the patient and should be followed longitudinally for development of symptoms. I agree with the treatment of addressing the C6-C7 level from an anterior approach.  Continued follow up with particular attention to the C4-C5 level is warranted.
Dr. Joshua Brooks

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