[Clinical efficacy of oblique lumbar interbody fusion combined with unilateral pedicle screw fixation via Wiltse approach in the treatment of lumbar spinal stenosis].

Objective: To evaluate the efficacy of oblique lumbar interbody fusion combined with unilateral pedicle screw fixation via Wiltse approach in the treatment of lumbar spinal stenosis.

Methods: From July 2017 to January 2019, 90 patients with lumbar spinal stenosis, including 38 males and 52 females, aged from 43 to 75 years old with an average of(59.9±8.8) years old, and were treated with oblique lumbar interbody fusion(OLIF) combined with Wiltse unilateral pedicle screw fixation. Surgical decompression and fixation was performed in 50 cases of single segment, 32 cases of double segments and 8 cases of three segments. The distribution of responsible segments included 8 cases of L-L, 12 cases of L-L and 30 cases of L-L on single segment, 10 cases of L-L and 22 cases of L-L on double segments, and 8 cases of L-L on three segments. The operation time, blood loss and occurrence of complications were recorded, Visual analogue scale(VAS), Oswestry Disability Index(ODI) and SF-36 scale were used to evaluate clinical efficacy. Lumbar X-ray and MRI were taken at three days after operation, interverterbral space height, intervertebral foraminal height, interverterbral foraminal area, and spinal canal area were measured, and interbody fusion was evaluated according to CT at half a year after operation.

Results: All patients were followed up from 12 to 33 months, with an average of (20.2±6.6) months. Mean operation time was (103.3±35.9) min, and mean intraoperative blood loss was (70.4±17.8) ml. VAS of low back pain leg pain, and ODI decreased from 6.2±1.1, 6.1±0.9 and (59.9±4.2)% to 2.7±0.5, 2.5±0.5 and (31.3±8.8)%. SF-36 scale significantly increased from (37.2±3.1) to (54.9±6.1) at the six months postoperation(<0.05). The intervertebral space height, intervertebral foraminal height, intervertebral foraminal area, and spinal canal area were significantly improved at 3 days after operation(<0.05). Six months after operation, CT scan showed well fusion in 87 cases, but 3 cases with poor fusion, including 1 case of single segment, 2 cases of multi-segments. The total fusion rate was 96.7% (87/90), the single segment fusion rate was 98.0% (49/50), and the multi-segments fusion rate was 95.0%(38/40). The overall incidence of complications was 17.8%(16/90), including transient iliopsoas muscle weakness in 5 cases (5.6%), endplate fracture in 2 cases (2.2%), peritoneal injury in 1 case (1.1%), postoperative hematoma in 1 case (1.1%), adjacent segment disease in 1 case(1.1%), and fusion cage subsidence in 6 cases (6.7%). Three patients was followed up for recurrent nerve root pain and the symptoms were relieved after revision operation. All complications were relieved or disappeared in varying degrees during the follow-up period, and there were no complications such as cage displacement and screw fracture.

Conclusion: OLIF combined with unilateral pedicle screw fixation via Wiltse approach is effective in treating lumbar spinal stenosis with minimally invasive advantages such as less trauma and less complications. Under the premise of strictly grasping the indications, this method could also achieve satisfactory clinical results in multi-segments oprations.