[Different pathoanatomic circumstances in bony lumbar foraminal stenosis have no influence on surgical outcome]

The purpose of this prospective observational study was to evaluate the clinical efficacy of nerve decompression in bony foraminal stenosis in different pathoanatomical circumstances.

Thirty-three consecutive patients (mean age: 63 years) were evaluated. All had leg-dominant monoradicular pain and were treated via a midline approach (lateral foraminotomy, with caudal resection of the pedicle in selected cases). Thirteen patients (39 %) had undergone prior lumbar surgery. The patients were divided into four pathoanatomic groups: (A) facet joint hypertrophy, n = 16; (B) dorsolateral spondylosis, n = 7; (C) height reduction of intervertebral disc, n = 3; (D) mixed group, n = 7. The clinical outcome was graded using a modified Prolo scale (pain and medication) and a visual analogue scale (VAS) after 2 and 12 months.

Based on the Prolo scale score, an excellent (n = 18) or good (n = 12) outcome was achieved in 91 % of the patients. There were no outcome differences among the four pathoanatomic groups. However, the groups B, C and D are small. Three patients in group B required revision surgery because of osteophytes in the transition area of the intra- and extraforaminal regions. All but one (97 %) of the patients experienced significant leg pain reduction following surgery as assessed by VAS (including the three revisions). No statistically significant associations were found between back pain, symptom duration, previous surgery, segment level, or pediculotomy and the outcome. There were no surgery-related complications.

Foraminal decompression alone for leg-dominant symptoms is a clinically effective procedure in the majority of patients without differences in the four pathoanatomic groups.