Degenerative Lumbar Spinal Stenosis

Objective1.The purpose of this study was to explore the correlation between the degree of single-segment central lumbar spinal stenosis?LSS?and lumbar X-ray measurements.2.The aim of the study was to evaluate the clinical effect of the limited area decompression,intervertebral fusion,and pedicle screw fixation for treating degenerative lumbar spinal stenosis?DLSS?with instability.Hemilaminectomy decompression,intervertebral fusion,and pedicle screw fixation for treating DLSS with instability as the control group.MethodThe clinical data of 60 patients with single-segment central lumbar spinal stenosis diagnosed and treated in the Department of Spinal Surgery of the Second Hospital of Lanzhou University from June 2017 to May 2019 were retrospectively analyzed.They were all male,aged 39-78 years,with an average age?59.18±10.06?years old.Based on the compression ratio?E?of the dural sac in magnetic resonance imaging?MRI?,patients were divided into three groups.On the lumbar cross-sectional MRI,the ratio of the transverse area?S₁?of the dural sac to the effective transverse area?S₀?of the spinal canal was measured to determine the degree of stenosis.Measuring Cobb angle of the lumbar vertebrae and calculating the difference of Cobb angle of the lumbar vertebrae?B?on overextension and hyperflexion X-ray film,the average height of the intervertebral space?D?,the lumbar vertebrae Cobb angle(L_1–5Cobb)and the intervertebral foramen?M?on lateral radiographs.Linear correlation analysis was used to determine the correlation between the single-segment central LSS and the various measurement parameters.Multiple linear regression analysis was used to analyze the factors affecting S₁/S₀.Follow-up of 54 patients?26 males and 28 females;average age,59.74±10.38 years?with DLSS with instability treated by limited area decompression,intervertebral fusion,and pedicle screw fixation?LIFP group?,and 52patients?23 males and 29 females;average age,61.40±9.55 years?as control group with hemilaminectomy decompression,intervertebral fusion,and pedicle screw fixation?HIFP group?.We assessed clinical effect according to the patients'functional outcome grading?Good to excellent,Fair,or Poor?,Oswestry Disability Index?ODI?and visual analogue scale?VAS?for low back pain and lower limb pain,which was administered preoperatively and at 3,6,and 12 months postoperatively.Fusion status was assessed by radiologists at the last follow-up.Treatment satisfaction was assessed according to the subjective evaluations of the patients.Results1.There were significant differences in S₁/S₀,E,B,L_1–5Cobb,and M among the three groups?P<0.05?.S₁/S₀ was positively correlated with E,B,L_1–5Cobb,and M?P<0.05?,but was not correlated with D?P=0.66?.After multiple linear regression analysis,B,L_1–5Cobb,and M were independently associated with S₁/S₀.2.At the 12-month follow-up,96.2%?52/54?and 90.3%?47/52?of group LIFP and HIFP belonged to good to excellent outcome categories,respectively,while 3.7%?2/54?and 9.6%?5/52?of group LIFP and HIFP belonged to fair respectively,neither group belonged to poor.Satisfaction rates of patients in group LIFP and group HIFP were 98.1%?53/54?and 92.3%?48/52?,respectively.The patients'functional outcome grading and satisfaction rate in group LIFP were better than that in group HIFP.The VAS for low back and lower limb pain and the ODI improved significantly during the 12 months after surgery?all P<0.001?in two groups.The VAS for low back and lower limb pain were no difference between two groups,however,the ODI of group LIFP was lower than that of group HIFP?P<0.001?.All patients achieved radiological fusion.Conclusion1.The B,L_1–5Cobb,and M parameters were independently associated with single-stage central LSS,and would likely be of particular value in evaluating the degree of single-segment central LSS;B,L_1–5Cobb,and M served as independent predictors of the degree of LSS.These findings will guide clinicians'decision-making in future.2.The limited decompression,interbody fusion and pedicle screw fixation?group LIFP?have similar effects with hemilaminectomy,interbody fusion and pedicle screw fixation?group HIFP?in the treatment of DLSS with instability.Moreover,the decompression range is smaller and the damage to the posterior structure of the spine is smaller.It is one of the optional methods for the treatment of DLSS with instability.