Lumbar vacuum disc, vertical instability, standalone endoscopic interbody fusion, and other treatments: an opinion based survey among minimally invasive spinal surgeons.

backgroundA diseased lumbar intervertebral vacuum disc void of any structurally intact tissue may be vertically unstable. A primary standalone endoscopic decompression and interbody fusion surgery in the treatment of vertical instability in patients with a vacuum disc may be a more reliable treatment than decompression alone.

methodsThe authors solicited responses to an online survey sent to spine surgeons by email, and chat groups on social media networks, including Facebook, WeChat, WhatsApp, and Linkedin. Descriptive and correlative statistics were employed to count the responses and compare the surgeon's responses recorded on a Likert scale from 1 (disagree) to 10 (agree) or in multiple-choice questions. Surgeons were asked about their familiarity with the concept of vacuum disc and vertical instability and how they would treat such patients. Kappa statistics and linear regression analysis of agreement of incoming responses were performed.

resultsA total of 1,165 surgeons accessed the survey. The completion rate was 22.78. The majority surgeons were very familiar with the concept of a "vacuum disc" as a sign of end-stage lumbar degenerative disc disease and a collapsing lumbar motion segment (182/273; 66.7%; Likert score 6.53). The majority of surgeons also thought that vertical instability precedes anterolateral lumbar instability (187/273; 68.5%; Likert score 6.64) and that a vacuum disc may cause vertical instability with symptomatic dynamic foraminal & lateral recess stenosis (222/273; 81%; Likert score 7.48), mechanical back pain (201/273; 73.1%; Likert score 7.48), and may cause sciatica-type low back and leg pain (179/273; 66.3%; Likert score 6.59). The majority of surgeons indicated that vacuum phenomenon on radiographic studies is associated with vertical instability and collapse resulting in dynamic foraminal and lateral recess stenosis and should be treated surgically (199/266; 73.7%; 7 missing responses; Likert score 6.86). Preferred treatments were decompression alone without fusion (P<0.014). There was consensus in support of fusion by TLIF or PLIF with a Likert score of 6.68 (184/266; 69.2%; 7 missing responses). There was no consensus on standalone fusion.

conclusionsVacuum phenomenon on radiographic studies is associated with a vertical instability and collapse, resulting in dynamic foraminal and lateral recess stenosis that should be treated surgically. Preferred surgical treatments were decompression alone, decompression with interbody fusion using just bone graft, and fusion employing TLIF or PLIF. Further research into the clinical significance of lumbar vacuum disc, vertical instability and its most appropriate surgical treatments if any is necessary.