Full‐Endoscopic Foraminotomy with a Novel Large Endoscopic Trephine for Severe Degenerative Lumbar Foraminal Stenosis at L5S1 Level: An Advanced Surgical Technique

To (i) introduce the technical notes of a novel full‐endoscopic foraminotomy with a large endoscopic trephine for the treatment of severe degenerative lumbar foraminal stenosis at L₅S₁ level; (ii) assess the primary clinical outcomes of this technique; (iii) compare the effectiveness of this full‐endoscopic foraminotomy technique and other previous techniques for lumbar foraminal stenosis. From January 2019 to August 2019, a retrospective study of L₅S₁ severe degenerative lumbar foraminal stenosis was performed in our center. All patients who were diagnosed with severe foraminal stenosis at L₅S₁ level and failed conservative treatment for at least 6 weeks were identified. Patients with segmental instability or other coexisting contraindications were excluded. A total of 21 patients were enrolled in the study. All patients were treated by full‐endoscopic foraminotomy using large endoscopic trephine. The visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated preoperatively and at 1, 3, 6 months, and 1 year after the surgery, and the modified MacNab criteria were used to evaluate clinical outcomes at the last follow‐up. There were 10 males and 11 females with a mean age of 66.38 ± 9.51 years. Five patients had a history of lumbar surgery. The mean operative time was 63.57 ± 25.74 min. The mean follow‐up time was 13.29 ± 1.38 months. The mean postoperative hospital stay time was 1.29 ± 0.56 days. The mean preoperative VAS score significantly decreased from 7.38 ± 1.02 to 2.76 ± 1.09 (t = 19.759, P < 0.01), 2.25 ± 1.02 (t = 21.508, P < 0.01), 1.60 ± 1.05 (t = 31.812, P < 0.01), and 1.45 ± 1.10 (t = 25.156, P < 0.01) at 1 month, 3 months, 6 months, and 1 year after the operation. The mean preoperative ODI score significantly decreased from 64.66% ± 4.91% to 30.69% ± 4.59% (t = 33.724, P < 0.01), 29.44% ± 4.50% (t = 32.117, P < 0.01), 24.22% ± 4.14% (t = 33.951, P < 0.01), and 22.44% ± 4.94% (t = 30.241, P < 0.01) at 1 month, 3 months, 6 months, and 1 year after the operation. At the last follow‐up, 19 patients (90.48%) got excellent or good outcomes. One patient suffered postoperative dysesthesia, and the symptoms were controlled by conversion treatment. One patient took revision surgery due to the incomplete decompression. There were no other major complications. Percutaneous endoscopic decompression is minimally invasive spine surgery. However, the application of endoscopic decompression for L₅S₁ foraminal stenosis is relatively difficult due to the high iliac crest and narrow foramen. Full‐endoscopic foraminotomy with the large endoscopic trephine is an effective and safe technique for the treatment of degenerative lumbar foraminal stenosis.     

Transvertebral anterior cervical foraminotomy: midterm outcomes of clinical and radiological assessments including the finite element method

Purpose

The aim of this study was to compare the clinical features, radiological changes, biomechanical effects, and efficacy in patients treated by transvertebral anterior foraminotomy. Preservation of segmental motion and avoidance of adjacent segment degeneration are theoretical advantages of transvertebral anterior foraminotomy. In practice, this procedure is minimally invasive and has shown good clinical results, especially in patients with unilateral cervical radiculopathy.

Method

We conducted a retrospective minimum 2-year follow-up study of the cervical spine of patients treated by transvertebral anterior foraminotomy at our institution. Radiological outcomes, which were estimated by measuring disc and functional spinal unit heights, and the angle and range of motion (ROM) from C2 to C7 of the functional spinal unit and adjacent segments were evaluated. Furthermore, a three-dimensional finite element method was used to biomechanically analyze the strength of the postoperative vertebral body.

Results

Between 2004 and 2009, 34 patients underwent surgery. The improvement rate was 94.2 %. The average flexion–extension ROM from C2 to C7 was 36.6 ± 16.6°. On plain radiographs, the disc height and ROM and height of the functional spinal unit in the operated segment were not significantly decreased relative to the preoperative levels. The finite element method also revealed that there was no difference in strength between the pre- and postvertebral bodies.

Conclusions

These results demonstrate that biomechanical stability was achieved. Transvertebral anterior cervical foraminotomy did not limit motion in the operated and adjacent segments and did not cause a significant decrease in disc and vertebral heights after surgery.     

Complications,outcomes, and need for fusion after minimally invasive posterior cervical foraminotomy and microdiscectomy

Background context

Posterior cervical foraminotomy (PCF) with or without microdiscectomy (posterior cervical discectomy [PCD]) is a frequently used surgical technique for cervical radiculopathy secondary to foraminal stenosis or a laterally located herniated disc. Currently, these procedures are being performed with increasing frequency using advanced minimally invasive techniques. Although the safety and efficacy of minimally invasive PCF/PCD (MI-PCF/PCD) have been established, reports on long-term outcome and need for secondary surgical intervention at the index or adjacent level are lacking.

Purpose

To determine the rates of complications, long-term outcomes, and need for secondary surgical intervention at the index or adjacent level after MI-PCF and microdiscectomy.

Study design

Retrospective analysis of a prospective cohort.

Patient sample

Seventy patients treated with MI-PCF and/or MI-PCD for cervical radiculopathy.

Outcome measures

Visual Analog Scale for neck/arm (VAS_N/A) pain and Neck Disability Index (NDI).

Methods

Ninety-seven patients underwent MI-PCF with or without MI-PCD between 2002 and 2011. Adequate prospective follow-up was available for 70 patients (95 cervical levels). The primary outcome assessed was need for secondary surgical intervention at the index or adjacent level. The secondary outcomes assessed included complications and improvements in NDI and VAS_N/A scores. All complications were reviewed. Mixed-model analyses of variance with random subject effects and autoregressive first-order correlation structures were used to test for differences among NDI, VAS_A, and VAS_N measurements made over time while accounting for the correlation among repeated observations within a patient. All statistical hypothesis tests were conducted at the 5% level of significance.

Results

Patients were followed for a mean of 32.1 months. Of 70 patients operated, there were 3 (4.3%) complications (1 cerebrospinal fluid leak, 1 postoperative wound hematoma, and 1 radiculitis), none of which required a secondary operative intervention. Five patients required an anterior cervical discectomy and fusion (eight total levels fused) on average 44.4 months after the index surgery. Of those, five (5.3%) were at the index level and three (2.1%) were at adjacent levels. Neck Disability Index scores improved significantly (p<.0001) immediately postoperatively and continued to decrease gradually with time. Visual Analog Scale for neck/arm scores improved significantly (p<.0001) from baseline immediately postoperatively but tended to plateau with time.

Conclusions

Minimally invasive PCF with or without MI-PCD is an excellent alternative for cervical radiculopathy secondary to foraminal stenosis or a laterally located herniated disc. There is a low rate (1.1% per index level per year) of future index site fusion and a very low rate (0.9% per adjacent level per year) of adjacent-level disease requiring surgery.     

单开门椎板成形术联合椎间孔切开术治疗脊髓型合并神经根型颈椎病疗效分析

目的评价颈后路单开门椎管成形术联合椎间孔切开术在治疗颈椎管狭窄症合并单侧神经根型颈椎病中的作用。方法回顾性研究2006年7月至2009年1月44例颈椎管狭窄症合并单侧神经根压迫症状患者,行颈后路单开门椎管成形术联合椎间孔切开术治疗的23例患者为A组,单纯行颈后路单开门椎管成形术治疗的21例患者为B组。引起椎间孔狭窄的原因:椎间盘突出、钩椎关节骨赘形成、关节突增生。神经根症状主要表现为单侧上肢疼痛、感觉减退、肌力下降和反射减弱。A组手术为颈后路单开门椎管成形术联合椎间孔切开术,关节突内侧缘切除范围均小于等于50%;B组仅行颈后路单开门椎管成形术。结果术后随访20～36个月,平均28个月。采用日本骨科协会评分法计算两组髓性症状术后改善率,差异无统计学意义;根性症状术后临床效果评价:A组优18例,良3例,一般2例;B组优7例,良3例,一般9例,差2例。结论对合并有单侧神经根型的颈椎管狭窄症患者,采用颈后路单开门椎管成形术联合椎间孔切开术可取得良好的手术效果。     

Small keyhole transuncal foraminotomy for unilateral cervical radiculopathy

Summary Interbody fusion after anterior discectomy may lead to acceleration of degenerative changes at adjacent levels. Although the posterior approach preserves the motion segment, decompression of the nerve root is indirect if “hard disc prolaps” is the main cause. Recently, a technique of microsurgical anterior cervical foraminotomy for the treatment of radiculopathy with preservation of the segment mobility was published. In this study, we present this technique with several modifications. Thirteen patients – 5 men and 8 women with an average age of 49 years – with unilateral radiculopathy resistant to conservative treatment underwent microsurgical anterior foraminotomy via a small keyhole transuncal approach. The base of the uncinate process (UP) was directly drilled in the trajectory to the intervertebral foramen without destroying the disc tissue. The vertebral artery between the transverse process was not exposed. Furthermore, the functional anatomy of the uncovertebral joint remained largely intact. All patients experienced complete relief of radiating pain. A cervical collar was not used. Mean follow-up time was 19 months. The mobility of the operated segment was preserved in each patient. No instability of the cervical spine was seen. The microsurgical anterior foraminotomy via a small keyhole transuncal approach is safe, minimally invasive, and represents an effective method to treat unilateral cervical radiculopathy caused by disc prolaps and/or uncovertebral osteophytes. Additionally, the segment mobility is preserved and prevents the acceleration of degenerative changes at adjacent levels.     

Morphometric Study of the Nerve Roots Around the Lateral Mass for Posterior Foraminotomy

Objective

Morphometric data on dorsal cervical anatomy were examined in an effort to protect the nerve root near the lateral mass during posterior foraminotomy.

Methods

Using 25 adult formalin-fixed cadaveric cervical spines, measurements were taken at the lateral mass from C3 to C7 via a total laminectomy and a medial one-half facetectomy. The morphometric relationship between the nerve roots and structures of the lateral mass was investigated. Results from both genders were compared.

Results

Following the total laminectomy, from C3 to C7, the mean of the vertical distance from the medial point of the facet (MPF) of the lateral mass to the axilla of the root origin was 3.2-4.7 mm. The whole length of the exposed root had a mean of 4.2-5.8 mm. Following a medial one-half facetectomy, from C3 to C7, the mean of the vertical distance to the axilla of the root origin was 2.1-3.4 mm, based on the MPF. Mean vertical distances from the MPF to the medial point of the root that crossed the inferior margin of the intervertebral disc were 1.2-2.7 mm. The mean distance of the exposed root was 8.2-9.0 mm, and the mean angle between the dura and the nerve root was significantly different between males and females, at 53.4-68.4°.

Conclusion

These data will aid in reducing root injuries during posterior cervical foraminotomy.     

Multilevel posterior foraminotomy with laminoplasty versus laminoplasty alone for cervical spondylotic myelopathy with radiculopathy: a comparative study

Background Context

Conventional laminoplasty is useful for expanding a stenotic spinal canal. However, it has limited use for the decompression of accompanying neural foraminal stenosis. As such, an additional posterior foraminotomy could be simultaneously applied, although this procedure carries a risk of segmental kyphosis and instability.

颈后路椎管成形术联合C_(4—5)椎间孔扩大术治疗多节段颈椎病疗效观察

目的观察颈后路椎管成形术联合C4—5椎间孔扩大术治疗多节段颈椎病的疗效。方法将142例多节段脊髓型颈椎病患者分为2组:A组67例行椎管成形术联合椎间孔扩大术,B组75例行单纯椎管成形术。观察2组神经功能恢复情况,轴性症状、颈椎曲度及稳定性的变化,比较C5神经根麻痹发生率。结果手术均顺利完成,未出现脊髓受损程度加重等情况发生。A组手术时间明显长于B组(P<0.05)。术后2组患者在神经功能恢复(JOA评分)、轴性症状(VAS评分)、颈椎曲度及颈椎活动度方面比较差异均无统计学意义(P均>0.05)。A组出现C5神经根麻痹1例(2%),B组出现7例(9%),2组比较差异有统计学意义(P<0.05)。结论颈后路椎管扩大成形术中,对C4—5椎间孔进行适当扩大可降低C5神经根麻痹的发生率,且不会对颈椎曲度、稳定性及术后轴性症状造成影响。     

Cervical Cord Decompression Using Extended Anterior Cervical Foraminotomy Technique

Objective

At present, gold-standard technique of cervical cord decompression is surgical decompression and fusion. But, many complications related cervical fusion have been reported. We adopted an extended anterior cervical foraminotomy (EACF) technique to decompress the anterolateral portion of cervical cord and report clinical results and effectiveness of this procedure.

Methods

Fifty-three patients were operated consecutively using EACF from 2008 to 2013. All of them were operated by a single surgeon via the unilateral approach. Twenty-two patients who exhibited radicular and/or myelopathic symptoms were enrolled in this study. All of them showed cervical cord compression in their preoperative magnetic resonance scan images.

Results

In surgical outcomes, 14 patients (64%) were classified as excellent and six (27%), as good. The mean difference of cervical cord anterior-posterior diameter after surgery was 0.92 mm (p<0.01) and transverse area was 9.77 mm² (p<0.01). The dynamic radiological study showed that the average post-operative translation (retrolisthesis) was 0.36 mm and the disc height loss at the operated level was 0.81 mm. The change in the Cobb angle decreased to 3.46, and showed slight kyphosis. The average vertebral body resection rate was 11.47%. No procedure-related complications occurred. Only one patient who had two-level decompression needed anterior fusion at one level as a secondary surgery due to postoperative instability.

Conclusions

Cervical cord decompression was successfully performed using EACF technique. This procedure will be an alternative surgical option for treating cord compressing lesions. Long-term follow-up and a further study in larger series will be needed.