Outcomes of lumbar decompression microsurgery.

[BACKGROUND] Microsurgical decompression of the spinal root in patients with herniated intervertebral discs is the most common spinal surgery. However, most national and foreign studies devoted to assessment of postoperative outcomes contain no consensus on the timing of radicular pain syndrome relief after decompression and predictors of unfavorable outcomes.

[OBJECTIVE] To determine the period of radicular pain syndrome relief after microsurgical decompression and to identify clinical and neuroimaging predictors of unfavorable postoperative outcomes.

[MATERIAL AND METHODS] The study included 58 patients aged 26-73 years with clinical manifestations of L5 radiculopathy following compression by L4-L5 herniated disc. We assessed neurological status, functional state (Oswestry Disability Index) and fatty infiltration of paravertebral muscles. Results. Isolated radicular pain was observed in 31% of patients, combination of pain syndrome and sensory disorders - 17%, pain syndrome and motor disorders - 24%, pain syndrome, sensory and motor disorders - 28% of patients. Duration of disease until surgery was significantly longer in women (=0.030). Complete relief of radicular pain immediately after surgery was observed in 24 (48%) patients. Sixteen (32%) patients had persistent pain syndrome for up to 1 month. Relief of radicular pain on the first postoperative day was significantly more common in patients without motor disorders (<0.014). The outcomes of microsurgical decompression did not depend on duration of disease (=0.551), sex (=0.794), age (=0.491) and degree of fatty infiltration of paravertebral muscles (=0.686).

[CONCLUSION] Radicular pain regresses within 4 weeks after microsurgical decompression. The predictor of unfavorable postoperative outcomes (long-standing pain syndrome and no functional improvement) is any preoperative motor impairment.