Spinous Process splitting Laminectomy: Clinical outcome and Radiological analysis of extent of decompression

Lumbar Spinous Process-Splitting Technique for Ligamentum Flavum Cyst Removal

BACKGROUND

 Laminotomy for lumbar stenosis is a well-defined procedure and represents a routine in every neurosurgical department. It is a common experience that the uni- or bilateral paraspinal muscle detachment, together with injury of the supra- and interspinous ligaments, can lead to postoperative pain. In the literature, the application of a minimally invasive technique, the lumbar spinous process-splitting (LSPS) technique, has been reported.

METHODS

 In this study, we present a case series of 12 patients who underwent LSPS from September 2019 to April 2020. Two patients had a cyst of the ligamentum flavum, eight a single-level lumbar canal stenosis (LCS), and two a two-level LCS. Moreover, we propose a novel morphological classification of postoperative muscle atrophy and present volumetric analysis of the decompression achieved.

RESULTS

 There were no complications related to this technique. In all patients, the vertebral canal area was more than doubled by the procedure. The muscle sparing showed grade A, according to our classification.

CONCLUSION

 To our knowledge, this is the first description of this surgical technique and the first LSPSL case series in Europe. Furthermore, cases of ligamentum flavum cyst removal using this safe and effective technique have not yet been reported.

Efficacy of Spinous Process Splitting Decompression Compared with Conventional Laminectomy for Degenerative Lumbar Stenosis

BACKGROUND

Spinous process splitting decompression (SPSD) is a minimally invasive surgical technique. We evaluated the clinical and radiological outcomes of SPSD compared with conventional laminectomy for the treatment of degenerative lumbar spinal stenosis.

METHODS

SPSD was performed in 144 patients (group 1) and conventional laminectomy was performed in 132 patients (group 2) for degenerative lumbar spinal stenosis. Operative time, blood loss, hospital stay, and complications were compared between groups. Functional outcome was evaluated 2 years after surgery by Oswestry Disability Index, visual analog scale for back pain and leg pain, and progress in walking capacity. Spinal anteroposterior diameter and cross-sectional area were assessed by magnetic resonance imaging and computed tomography.

RESULTS

Both groups showed significant improvement in mean functional outcome scores of Oswestry Disability Index and mean visual analog scale for back and leg pain after surgery (P < 0.001), although the differences in scores between the groups (P > 0.05) were not statistically significant. Walking capacity was reported as "much better" and "moderately better" in 89% of patients in group 1 and 87.8% of patients in group 2 (P > 0.05). On the basis of radiographic findings, satisfactory neurological decompression was achieved in group 1 (72.2% increase in mean spinal anteroposterior diameter, 102.5% increase in cross-sectional area) and group 2 (80.3% in mean spinal anteroposterior diameter, 108.8% increase in cross-sectional area) (P > 0.05).

CONCLUSIONS

Patients who underwent SPSD for lumbar spinal decompression had comparable functional recovery rates correlated with clinical and radiological improvement to patients who underwent conventional laminectomy.

Radiological Analysis of Minimally Invasive Microscopic Laminectomy for Lumbar Canal Stenosis with a Focus on Multilevel Stenosis and Spondylolisthesis

OBJECTIVE

We retrospectively compared the radiological and clinical outcomes of two different surgical techniques (lumbar spinous process splitting laminectomy [LSPSL] and unilateral laminotomy for bilateral decompression [ULBD]) to treat lumbar spinal canal stenosis (LCS).

METHODS

We performed a retrospective comparative study of 141 consecutive patients with an average age of 70.8 ± 9.4 years who had undergone LSPSL or ULBD for LCS between April 2015 and April 2019. None of the patients had developed remote fractures of the spinous processes using either technique. These cases were divided into 2 groups: group L, 73 patients who had undergone LSPSL from April 2015 to April 2017; and group U, 68 patients who had undergone ULBD from May 2017 to April 2019. The clinical and radiological outcomes and surgical complications at the 1-year postoperative follow-up period were evaluated.

RESULTS

We found no significant differences in the operative time between the 2 groups. However, group U had had significantly less blood loss than group L. The facet joints were significantly well preserved in group U. We examined the multilevel and spondylolisthesis cases separately and found that both surgical procedures were equally effective and that the visual analog scale scores for back or leg pain and Japanese Orthopaedic Association scores had significantly improved postoperatively in each group. Group U showed better outcomes in terms of LCS recurrence, with 3 patients in the group L requiring repeat surgery.

CONCLUSIONS

We found both ULBD and LSPSL to be safe and effective techniques for LCS, even for patients with spondylolisthesis and multilevel disease. ULBD was superior in terms of recurrence prevention, preservation of the facet joints, and less blood loss.

Spinous-Process-Splitting Versus Conventional Decompression for Lumbar Spinal Stenosis: Comparative Study with Respect to Short-Term Postoperative Pain and Analgesics Use

OBJECTIVE

Several microsurgical techniques are available for the decompression of lumbar spinal stenosis (LSS). More recently, a spinous process-splitting laminectomy (SPSL) technique was introduced, with the premise of diminishing paraspinal muscle damage. This study aims to compare the neurologic and functional outcomes, as well as the differences in early postoperative pain and analgesic use during hospitalization after conventional decompression (CD) versus SPSL surgery for LSS.

METHODS

Single-center retrospective analysis of all spinal decompression procedures (CD or SPSL) that were performed or supervised by one consulting spine surgeon, performed for LSS between 2015 and 2020. Preoperative neurologic symptoms, functional outcomes, as well as perioperative analgesic use and reported pain scales during hospitalization were analyzed.

RESULTS

From a total of 106 patients, 58 were treated using CD and 48 using SPSL. In both groups, around one-third of the patients were taking opiates preoperatively (38% for CD, 31% for SPSL). Patients submitted to SPSL reported more pain on first postoperative day but significantly less pain in the further postoperative course (day 3 numeric rating scale [NRS] 2.4 vs. 3.4, P = 0.03 and on day 5 NRS 2.5 vs. 3.7, P = 0.009). Equal or less cumulative doses of analgesics were administered postoperatively (significantly less paracetamol on day 5 compared with CD; P = 0.013). Both groups showed a similarly favorable outcome in terms of improved mobility and there were no significant differences between complications and re-stenosis rates between both techniques.

CONCLUSIONS

Patients treated with SPSL technique for LSS showed an equivalent favorable functional outcome compared to CD. However, SPSL patients showed significantly less subacute postoperative pain while using equal amounts or fewer analgesics postoperatively.

Placement of surgical spinal cord stimulation (SCS) leads using spinal process splitting laminotomy (SPSL): Technical note

OBJECTIVE

Spinal Cord Stimulation (SCS) has become an established method within the therapy of chronic pain allowing for significant pain relief. Surgical leads usually have to be implanted via a surgical procedure involving uni- or bilateral muscle detachment and partial laminectomy.

METHODS

We present the application of a novel minimal invasive microsurgical approach for lead placement which combines the beneficial advantages of anatomical midline lead placement whilst preserving the midline structures, avoiding muscle detachments and thus ensuring spinal stability: spinal process splitting laminotomy (SPSL).

CONCLUSION

The spinal process splitting laminotomy (SPSL) technique can be successfully applied to introduce the surgical leads for spinal cord stimulation.

Radiographic outcomes of endoscopic decompression for lumbar spinal stenosis

OBJECTIVE

Lumbar central stenosis can theoretically be decompressed with minimal bone removal via an endoscopic approach. Although multiple studies have demonstrated an adequate radiographic decompression, none has quantified the volume of bone removal after endoscopic decompression. The objective of this study was to quantify the 3D volume of bone removed from the lamina and facet joints during endoscopic decompression for lumbar central and lateral recess stenosis.

METHODS

This retrospective study included adults with lumbar spinal stenosis who underwent endoscopic decompression of a single level or 2 noncontiguous lumbar levels. Central stenosis on MRI was graded preoperatively and postoperatively using the Schizas scale. A computer program was developed in MATLAB to semiautomatically perform a 3D volumetric analysis of preoperative and postoperative lumbar CT scans. The volumetric percentage of bone removed from the lamina and facet joints ipsilateral and contralateral to the side of approach was quantified.

RESULTS

Nineteen patients with 21 treated lumbar levels were included in the study. Preoperatively, the number of levels with Schizas stenosis grades B, C, and D were 5, 12, and 4, respectively. Stenosis grades improved postoperatively to grades A, B, C, and D for 17, 3, 1, and 0 levels, respectively. All levels improved by at least 1 stenosis grade. The volumetric percentage of laminar bone removed was 15.5% (95% CI 11.2%–19.8%, p < 0.001) from the ipsilateral lamina and 8.8% (95% CI 5.7%–11.8%, p < 0.001) from the contralateral lamina. The percentage of facet joint resection was 5.3% (95% CI 4.2%–6.4%, p < 0.001) and 4.3% (95% CI 2.2%–6.4%, p < 0.001) for the ipsilateral and contralateral facet joints, respectively. Average pain scores, as measured by the visual analog scale, improved from 7.9 preoperatively to 2.2 by 3–10 months postoperatively (p < 0.001).

CONCLUSIONS

Endoscopic lumbar decompression achieves improvement in the radiographic grade of lumbar central stenosis with minimal bone removal from the lamina and facet joints. Future prospective studies are needed to validate the findings of this study with more comprehensive clinical outcomes.

Restoration of the Spinous Process Following Muscle-Preserving Posterior Lumbar Decompression via Sagittal Splitting of the Spinous Process

Background

In lumbar spinal stenosis, spinous process-splitting decompression has demonstrated good clinical outcomes with preservation of the posterior ligamentous complex and paraspinal muscles in comparison to conventional laminectomy, but the radiological consequence and clinical impact of the split spinous processes have not been fully understood.

Methods

Seventy-three patients who underwent spinous process-splitting decompression were included. The bone union rate and pattern were evaluated by computed tomography performed 6–18 months after surgery and compared among subgroups divided according to the number of levels decompressed and the extent of spinous process splitting. The bone union pattern was classified into three categories: complete union, partial union, and nonunion. The visual analog scale (VAS) score, Oswestry disability index (ODI), and walking distance assessed both before and 24–36 months after surgery were compared among subgroups divided according to the union pattern of the split spinous process.

Results

Overall, the rates of complete union, partial union, and nonunion were 51.7%, 43.2%, and 5.1%, respectively. In the subgroup with partial splitting of the spinous process, the rates were 85.7%, 14.3%, and 0%, respectively; those of the subgroup with total splitting of the spinous process were 32.9%, 59.2%, and 7.9%, respectively. With single-level decompression, a higher rate of union was observed compared with multilevel decompression. The VAS, ODI, and walking distance were significantly improved after surgery and did not differ according to the degree of union of the split spinous process.

Conclusions

We found that the single-level operation and partial splitting of the spinous process were favourable factors for obtaining complete restoration of the posterior bony structure of the lumbar spine in spinous process-splitting decompression.

Minimally Invasive Lumbar Spinal Decompression in Elderly Patients with Magnetic Resonance Imaging Morphological Analysis

Study Design

Case-control study.

Purpose

In this study, we aimed to investigate clinical outcomes and morphological features in elderly patients with lumbar spinal stenosis (LSS) who were treated by minimally invasive surgery (MIS) unilateral laminectomy for bilateral decompression (ULBD) using a tubular retractor.

Overview of Literature

Numerous methods using imaging have been attempted to describe the severity of spinal stenosis. But the relationship between clinical symptoms and radiological features remains debatable.

Objective

In this study, we aimed to investigate clinical outcomes and morphological features in elderly patients with LSS who were treated by MIS-ULBD.

Methods

We methodically assessed 85 consecutive patients aged >65 years who were treated for LSS. The patients were retrospectively analyzed in two age groups: 66-75 years (group 1) and >75 years (group 2). Clinical outcomes were assessed using the Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and the modified MacNab criteria. Outcome parameters were compared between the groups at the 1-year follow-up. Core radiologic parameters for central and lateral stenosis were analyzed and clinical findings of the groups were compared.

Results

At the 1-year follow-up, patients in both groups 1 and 2 demonstrated significant improvement in their VAS and ODI scores. All clinical outcomes, except postoperative ODI, were not significantly difference between the groups. In addition, no significant difference was noted in the preoperative radiological parameters between the groups. There was no statistically significant correlation between radiological parameters and clinical symptoms or their outcomes. Moreover, no differences were noted in perioperative adverse events and in the need for repeat surgery at follow-ups between the groups.

Conclusions

MIS-ULBD by tubular approach is a safe and effective treatment option for elderly patients with LSS. Clinical outcomes in patients with LSS and aged >75 years were comparable with those in patients with LSS and aged 66-75 years. Moreover, we did not find any correlation between radiological parameters and clinical outcomes in either of the two patient groups.

Impact of pedicle-lengthening osteotomy on spinal canal volume and neural foramen size in three types of lumbar spinal stenosis

Objectives

Pedicle-lengthening osteotomy is a novel surgery for lumbar spinal stenosis (LSS), which achieves substantial enlargement of the spinal canal by expansion of the bilateral pedicle osteotomy sites. Few studies have evaluated the impact of this new surgery on spinal canal volume (SCV) and neural foramen dimension (NFD) in three different types of LSS patients.

Methods

CT scans were performed on 36 LSS patients (12 central canal stenosis (CCS), 12 lateral recess stenosis (LRS), and 12 foraminal stenosis (FS)) at L4-L5, and on 12 normal (control) subjects. Mimics 14.01 workstation was used to reconstruct 3D models of the L4-L5 vertebrae and discs. SCV and NFD were measured after 1 mm, 2 mm, 3 mm, 4 mm, or 5 mm pedicle-lengthening osteotomies at L4 and/or L5. One-way analysis of variance was used to examine between-group differences.

Results

In the intact state, SVC and NFD were significantly larger in the control group compared with the LSS groups (P<0.05). After lengthening at L4, the percentage increase in SCV (per millimetre) was LRS>CCS>FS>Control. After lengthening at L5 and L4-L5, the percentage increase in SCV (per millimetre) was LRS>FS>CCS>Control. After lengthening at L4 and L4-L5, the percentage increase in NFD (per millimetre) was FS>CCS>LRS>Control. After lengthening at L5, the percentage increase in NFD (per millimetre) was CCS>LRS>control>FS.

Conclusions

LRS patients are the most suitable candidates for treatment with pedicle-lengthening osteotomy. Lengthening L4 pedicles produced larger percentage increases in NFD than lengthening L5 pedicles (p < 0.05). Lengthening L4 pedicles may be the most effective option for relieving foraminal compression in LSS patients.

Cite this article: P. Li, L. Qian, W. D. Wu, C. F. Wu, J. Ouyang. Impact of pedicle-lengthening osteotomy on spinal canal volume and neural foramen size in three types of lumbar spinal stenosis. Bone Joint Res 2016;5:239–246. DOI: 10.1302/2046-3758.56.2000469.