Unilateral Modified Posterior Lumbar Interbody Fusion Combined With Contralateral Lamina Fenestration Treating Severe Lumbarspinal Stenosis: A Retrospective Clinical Study

Clinical efficacy of percutaneous endoscopic posterior lumbar interbody fusion and modified posterior lumbar interbody fusion in the treatment of lumbar degenerative disease

BACKGROUND

To compare the early clinical efficacy of percutaneous endoscopic posterior lumbar interbody fusion (PE-PLIF) and modified posterior lumbar interbody fusion (MPLIF) in the treatment of lumbar degenerative disease (LDD).

METHODS

A total of 37 patients who underwent PE-PLIF and 58 patients who underwent MPLIF from March 2019 to January 2022 were retrospectively reviewed. The operation time, intraoperative blood loss, post-operative hospitalization time, and post-operative bedrest time were recorded. The visual analogue scale (VAS) scores of leg pain and low back pain, Japanese Orthopaedic Association (JOA) scores, and the Oswestry Disability Index (ODI) scores were evaluated and compared before the operation, 3 days after the operation, 1 week after the operation, 1 month after the operation, 6 months after the operation and at the last follow-up. The modified MacNab's criteria were applied at the last follow-up. The fusion rate and surgical-related complications during follow-up were recorded.

RESULTS

The average operation time in the PE-PLIF group was highly significant longer than that in the MPLIF group (P < 0.01). The intraoperative blood loss, post-operative hospitalization time, and post-operative bedrest time were significantly less in the PE-PLIF group than those in the MPLIF group (P < 0.01). There were highly significant differences in VAS scores of leg pain, VAS scores of low back pain, JOA scores, ODI scores at the last follow-up compared with those before the operation in the two groups (P < 0.01). Three days after the operation and 1 week after the operation, the VAS scores for low back pain and ODI were highly significant less in the PE-PLIF group than that in the MPLIF group (P < 0.01). Three days after the operation, the JOA scores were highly significant higher in the PE-PLIF group than that in the MPLIF group (P < 0.01). All patients showed intervertebral fusion at 6 months after the operation. Two patients (5.4%) in the PE-PLIF group experienced complications.

CONCLUSION

Both PE-PLIF and MPLIF surgery were clinically effective and safe for patients with single-segment LDD. PE-PLIF surgery is a promising technique that can be used as an alternative treatment for single-segment LDD.

Biomechanical effects of individualized artificial titanium alloy lamina implantation after laminectomy: A finite element analysis

Background and objectives: Laminectomy is a common surgical procedure in spine surgery. However, disruption of the posterior ligamentous complex of the spine may lead to a range of postoperative complications. Artificial lamina as a kind of bionic implant can well restore the posterior spinal structure. In this study, an individualized artificial titanium alloy lamina was designed to reconstruct the posterior spinal structure after laminectomy and explored its biomechanical effects, which could provide a theoretical basis for the clinical application of the artificial lamina.

Methods: Three finite element models were constructed, namely the nonlinear and non-homogeneous intact model of the whole lumbar spine, the lumbar decompression alone surgical model, and the artificial lamina implantation surgical model. The range of motion, intradiscal pressure, and annulus fibrosus peak stress were compared between the three models at the surgical and adjacent segments. The stresses of the artificial lamina and fixation screws were also analyzed for the four movement states.

Results: Compared with the intact model, the lumbar decompression alone surgical model showed an increase in range of motion, intradiscal pressure, and annulus fibrosus peak stresses at the surgical segment and adjacent segments under all conditions. The artificial lamina implantation surgical model showed an increase in these measurements only in flexion, increasing by 7.5%–22.5%, 7.6%–17.9%, and 6.4%–19.3%, respectively, over the intact model, while there was little difference under other conditions. The peak stresses in both the screw and the artificial lamina were highest in axial rotation, i. e. 46.53 MPa and 53.84 MPa, respectively. Screw stresses were concentrated on the connection between the screw and the artificial lamina, and artificial lamina stresses were concentrated on the spinous root, around the screw hole, and the contact with the vertebral body.

Conclusion: An individualized artificial titanium alloy lamina can effectively reduce the range of motion, intradiscal pressure, and annulus fibrosus stress at the surgical segment and adjacent segments. The application of artificial lamina could better preserve the biomechanical properties of the intact lumbar spine and reduce the risk of adjacent segmental disease.