title: [Comparison of treatment with micro endoscopic discectomy and posterior lumbar interbody fusion using single and double B-Twin expandable spinal spacer].
abstract: OBJECTIVE
  To compare the therapeutic effect of posterior lumbar interbody fusion by single and double B-Twin expandable spinal spacer with micro endoscopic discectomy (MED) for lumbar intervertebral disc protrusion accompanying degenerative instability.
  
  
  METHODS
  From March 2006 to May 2008, 45 patients with lumbar intervertebral disc protrusion accompanying degenerative instability were admitted and managed with posterior lumbar interbody fusion by B-Twin expandable spinal spacer with MED. The patients were randomly assigned to treatment with single B-Twin (Single group, n = 24) or double B-Twin (Double group, n = 21). There were 16 males and 8 females, with an average age of 45.5 years (43 - 60 years) in Single group; 13 males and 8 females, with an average age of 43.7 years (44-61 years) in Double group. All the cases suffered from only one level disc protrusion, L(3-4) 2 cases, L(4-5) 29 cases and L₅-S₁ 14 cases. Clinical outcomes were evaluated with surgical time, blood loss, visual analogue scale (VAS) scores preoperatively, 1, 3, 6 month postoperatively. Oswestry disability questionnaire (ODI) of the preoperative, 1 month postoperative, and latest follow-up and the disk space heights.
  
  
  RESULTS
  Forty three patients were followed-up for 1 to 3 years after surgery. The mean surgical time of Double group was longer than Single group [(152 ± 32) min vs. (91 ± 15) min, P < 0.01]. The average blood loss in Double group was more than that in Single group [(146 ± 73) ml vs. (95 ± 58) ml, P < 0.01]. The mean time of hospital stay in Single group was similar to that in Double group [(11.0 ± 3.2) d vs. (10.9 ± 3.3) d, P > 0.05]. Both groups could keep the disk space heights till the last follow-up [(7.7 ± 1.8) mm vs. (8.5 ± 1.7) mm]. In the 6 months follow-up post operation, the VAS score decreased from (8.1 ± 1.8) to (2.0 ± 1.0) in Single group, and (8.1 ± 1.9) to (2.1 ± 1.0) in Double group. At the last follow-up, the ODI decreased from (36 ± 7)% to (10 ± 4)% in Single group and (37 ± 6)% to (9 ± 4)% in Double group, but there was no significant difference between the two groups (P > 0.05). All the cases achieved fusion at the last follow-up, 3 patients in Single group and 2 patients in Double group suffered from intractable low back pain. One of the fins broke in one patient without any uncomfortable feeling.
  
  
  CONCLUSIONS
  Compared with the management of lumbar intervertebral disc protrusion accompanying degenerative instability by double B-Twin expandable spinal spacer with micro endoscopic discectomy, the single B-twin can get similar clinical outcomes, but shorter surgical time, less blood loss and less medical costs.
authors.affiliation: Department of Orthopedics, First Hospital of Dalian Medical University, Dalian 116011, China.
authors.forename: De-qiang
authors.initials: DQ
authors.lastname: Zhang
authors.forename: Qun
authors.initials: Q
authors.lastname: Yang
authors.forename: Chang-ming
authors.initials: CM
authors.lastname: Jiang
authors.forename: Chun-ming
authors.initials: CM
authors.lastname: Wu
authors.forename: Kai
authors.initials: K
authors.lastname: Ma
authors.forename: Kai
authors.initials: K
authors.lastname: Tang
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.forename: Bo
authors.initials: B
authors.lastname: Wang
mesh_terms: D000328:Adult; D004724:Endoscopy; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008159:Lumbar Vertebrae; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013123:Spinal Fusion / Q000379:methods*; D016896:Treatment Outcome