Comparative Clinical Effectiveness of Tubular Microdiscectomy and Conventional Microdiscectomy for Lumbar Disc Herniation

A Systematic Review and Network Meta-Analysis

Yinqing Wang, MD; Zeyan Liang, MD; Jianfeng Wu, MD; Songjie Tu, MD; Chunmei Chen, MD, PhD


Spine. 2019;44(14):1025-1033. 

In This Article

Abstract and Introduction


Study Design: This study is a systematic literature review and meta-analysis.

Objective: To evaluate the efficacy of tubular microdiscectomy (TMD) compared with conventional microdiscectomy (CMD) for lumbar disc herniation (LDH).

Summary of Background Data: TMD has developed rapidly due to reduced tissue trauma by minimization of the required access to spine and disc herniation; however, CMD remains the standard of care for this patient group. To date, it remains debatable whether TMD is superior to CMD for LDH.

Methods: We performed a comprehensive database search of PubMed, EMBASE, and Cochrane Central Register of Controlled Trails for prospective randomized controlled trials (RCTs), through using Medical Subject Headings (MeSH) terms "microdiscectomy," "tubular microdiscectomy," "minimally invasive surgery," and "spinal disease." The retrieved results were last updated on March 15, 2018. Two independent investigators selected qualified studies, extracted indispensable data, assessed risk of bias of original papers. The Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach was used to grade quality of evidence. If I 2 >50, the heterogeneity is considerable.

Results: Four RCT studies (total n = 605), involving 610 individuals with a follow-up period of no less than 12 months, were selected for further review. We assessed these studies as low overall risk of bias. There was low-quality evidence that TMD was superior to CMD considering postoperative Oswestry Disability Index scores (SMD, −3.43, 95% CI, −4.64 to −2.21, P < 0.00001). Compared with CMD, the TMD group exhibited significantly worse Short Form-36 physical function scores (SMD, −4.83, 95% CI, −8.94 to −0.72, P = 0.02). There were no significant differences in the visual analogue scale (P = 0.30), operative time (P = 0.68), dural tear (P = 0.52), and reoperation (P = 0.98).

Conclusion: The benefits 1 year after TMD were similar to that of CMD. There was no significant difference in the incidence of reoperation and dural tear.

Level of Evidence: 1


Lumbosacral radicular syndrome, or sciatica, is responsible for sizeable personal or societal costs and is often caused by lumbar disc herniation (LDH), of which natural process is usually favorable.[1] Surgery is recommended when patients with intractable pain are refractory to conservative treatment or experience progressive neurological deficits.[2] The goal of lumbar discectomy is to remove pathological disc material to decompress the nerve root and relieve symptoms.[3]

In 1934, the first successful lumbar disc operation was described by Mixter and Barr.[4] Since then, a variety of innovative and minimally microinvasive techniques have been developed. With the application of the surgical microscope and further enhancement of visualization, conventional microdiscectomy was introduced by Caspar[5] and Yasargil,[6] respectively. In 1997, Foley and Smith[7,8] introduced minimally invasive transmuscular tubular discectomy, and performed minimally invasive discectomy using a combination of tubular retractors and trocar systems with endoscopy. In 2002, Greiner-Perth et al[9] reported that combining tubular retractors and trocar systems with surgical microscopy for LDH overcomes disadvantages of the two-dimensionality of the endoscopic image.

The rationale behind trocar systems, replacing conventional subperiosteal muscle dissection by the muscle-splitting transmuscular approach of tubular microdiscectomy, is less tissue trauma caused by surgery and a subsequent faster rate of recovery.[7] Although, in theory, TMD should benefit the patient, CMD currently remains the standard procedure for LDH.[10,11] In 2008, the first RCT study[12] comparing TMD with CMD was reported, but there were no significant differences except reduced postoperative consumption of analgesics in the TMD group. Subsequently, some RCT studies[13–15] were successively introduced, though evidences supporting that TMD was superior in efficacy compared with CMD remained insufficient. As such, this study aimed to systematically review randomized controlled clinical studies relevant to determining the clinical effectiveness of TMD versus CMD for LDH.