Minimally invasive posterior cervical foraminotomy for treatment of radiculopathy : An effective, time-tested, and cost-efficient motion-preservation technique.

OBJECTIVE: To relieve foraminal root impingement due to lateral soft disc fragments, bony spurs, or other rarer causes.

INDICATIONS: Soft disc fragment whose bulk is >2/3 lateral to the lateral border of the thecal sac. Intraforaminal dorsal bony narrowing of the root canal. Intraforaminal synovial cyst, extra/intradural tumor.

CONTRAINDICATIONS: Paramedian and median soft/hard disc protrusions. Kyphosis of the index level.

SURGICAL TECHNIQUE: Patient prone in reverse Trendelenburg position with the head fixed in a Mayfield clamp. Cervical spine horizontal and approximately 10 cm above the heart. Microscope from skin to skin. Skin incision: 25 mm, about 10 mm off the midline. Microsurgical blunt splitting of the muscle layers along the fiber direction. An expandable tubular retractor or a miniaturized speculum counter retractor, table anchored, is centered on the target lamino-facet junction as confirmed by fluoroscopy. Drilling of the keyhole. The axilla of the root is exposed while preserving most of the facet complex. Epidural exploration until an extruded or subligamentous disc fragment(s) is removed. If needed, removal of the dorsal bone overlying the root exiting in the foramen. The adequacy of decompression is assessed by palpating the root along its course with a small nerve hook. Closure by layers. No drain.

POSTOPERATIVE MANAGEMENT: Same day mobilization. No external brace.

RESULTS: Minimally invasive posterior cervical foraminotomy (MI-PCF) was used to treat 103 patients for unilateral cervical radiculopathy. Mean follow-up was 32 months. Despite 1 cerebrospinal fluid leak, 1 wound hematoma, and 1 radiculitis during the early postoperative period, no patients required revision surgery. Visual analog scale (VAS) scores for neck/shoulder and arm improved significantly in the early postoperative period (3 months) and were maintained with time (p < 0.001). Neck Disability Index (NDI) improved significantly postoperatively but worsened slightly during follow-up (p < 0.001). Anterior decompression and fusion (ACDF) was required at the index level by 3 patients (mean: 55 months later) and at the adjacent level by 4 patients (mean: 27 months later).