Modified Percutaneous Lumbar Foraminoplasty and Percutaneous Endoscopic Lumbar Discectomy: Instrument Design, Technique Notes, and 5 Years Follow-up.

BACKGROUND: Conventional percutaneous endoscopic lumbar discectomy (PELD) with an "inside-outside" technique has 4.3% - 10.3% surgical failure rate, especially in central herniated discs (HDs), migrated HDs, and axillary type HDs. PELD with foraminoplasty has been used for complex HDs. Percutaneous lumbar foraminoplasty (PLF), which is performed with a trephine or bone reamer introduced over a guidewire without a protective working cannula in the original Tessys technique, can quickly cut the hypertrophied bony structure under fluoroscopic guidance, and risk injury to the exiting and traversing nerve roots. STUDY DESIGN: A prospective cohort study. SETTING: Hospital and outpatient surgical center. OBJECTIVE: To evaluate the outcome and safety of modified PLF-PELD with a specially designed instrument for complex uncontained lumbar HDs. METHOD: From April of 2007 to April of 2009, 148 patients with uncontained lumbar HDs were treated with modified PLF-PELD. Magnetic resonance imaging (MRI) checkup was performed the next morning after the operation. Outcomes of symptoms were evaluated by follow-up interviews at 3 months, 6 months, one year, and 5 years after surgery. Low back pain and leg pain were measured by visual analog scale (VAS) score (1 - 100). Functional outcomes were assessed by using the Oswestry Disability Index (ODI) and modified MacNab criteria. RESULTS: Follow-up data were obtained from 134 cases, including 14 cases on L3-4, 78 cases on L4-5, and 42 cases on L5-S1. One hundred-eight cases were prolapse type, while 26 cases were sequestration type. Pre-operative symptoms and deficits included nerve root dermatome hypoesthesia in 98 patients (73%), nerve root myotome muscle weakness in 32 patients (23%), and weakening or disappearance of tendon reflex in 43 patients (32%). No case required conversion to an open procedure during the surgery. Low back pain and leg pain were significantly relieved immediately after surgery in all patients. MRI examination showed adequate removal of HD in all patients. VAS scores and ODI values were significantly lower at all time points after surgery than before surgery. The percentage of pain relief in leg pain was significantly higher than that in low back pain (P < 0.01). But there was no significant correlation between duration of the preoperative symptoms and the percentage of pain relief. MacNab scores at 5 years after surgery were obtained from 134 patients. Seventy-five cases were rated "excellent"; 49 were rated "good," Five patients experienced heavier low back pain, thus being classified as "fair." Five cases with recurrence were rated "poor." Preoperative and postoperative (5 years follow-up) related nerve root function status was compared. Sensation and muscle strength recovered significantly (P < 0.01), while tendon reflex was not changed (P = 0.782). No patients had infections. Five patients were complicated with dysesthesia in distribution of the exiting nerve that was all operated at L5-S1. Complaints were reduced one week after treatment with medium frequency pulse electrotherapy. Five cases required a revision surgery after recurrence. LIMITATIONS: This is an observational clinical case series study without comparison. CONCLUSION: Modified PLF-PELD with a specially designed instrument is a less invasive, effective and safe surgery for complex uncontained lumbar DH.Key words: Lumbar disc herniation, minimally invasive treatment, foraminoplasty, percutaneous endoscopic lumbar discectomy.

The strategy and early clinical outcome of full-endoscopic L5/S1 discectomy through interlaminar approach.

OBJECTIVE: To analyze the surgical strategy, safety and clinical outcome of full-endoscopic discectomy through interlaminar approach in the case of L5/S1 intervertebral disc excision. METHODS: From April 2011 to December 2011, 72 cases of intracanalicular non-contained disc herniations at L5/S1 level were treated with full-endoscopic discectomy through interlaminar approach. L5/S1 disc herniation was divided into three types according to position of herniated disc related to S1 nerve root: axilla type, ventral type and shoulder type. Axilla approach was selected for axilla type while shoulder approach was selected for ventral type and shoulder type. After operation, MRI was reexamined to evaluate the resection completeness of prolapsed disc material. Visual analog scales (VAS) of low back pain and sciatica, and Oswestry disability index (ODI) were recorded in certain preoperative and postoperative time points. MacNab scores were evaluated at the 12-month follow-up. RESULTS: All operations were completed without conversion to other surgical techniques. Average operation time was 45 min (20-80 min). Only one reoccurrence was revised with microendoscopic discectomy. No nerve injury and infection were complicated. Postoperative ODI and VAS of low back pain and sciatica were significantly decreased in each time point (P < 0.05). MacNab scores of 12-month follow-up include 44 excellent, 26 good, 1 fair and 1 poor. CONCLUSION: With proper selection between axilla approach and shoulder approach according to the sites of prolapsed or sequestered disc materials, full-endoscopic L5/S1 discectomy through interlaminar approach is a safe, rational and effective minimally invasive spine surgery technique with excellent clinical short-term outcomes.

Evaluation of endoscopic dorsal ramus rhizotomy in managing facetogenic chronic low back pain.

OBJECTIVE: To study the effectiveness of surgical dorsal endoscopic rhizotomy for the treatment of facetogenic chronic low back pain. METHODS: From April 2011 to November 2011, 58 patients who were diagnosed with lumbar facetogenic chronic low back pain (CLBP) and thereafter experienced >80% reliefs of pain with two comparative lumbar medial branch blocks were recruited in the study. Of those 58 patients, 45 cases (the operation group) received dorsal endoscopic rhizotomy, and the remaining 13 cases (the conservative group) received conservative treatment. Patients' preoperative and postoperative VAS score, percentage of pain relief and the MacNab score were analyzed and compared. Anatomic variations and any possible complications were recorded. RESULTS: In the operation group, VAS scores of pain (low back/referred) at any time point postoperatively were significantly lower than that before MBB (P<0.05), which, however, showed no significant difference as compared to the scores after MBB (P>0.05). In the conservative group, VAS scores of pain (low back/referred) at any time point postoperatively with conservative treatment decreased significantly compared with that before MBB (P<0.05) and were significantly higher than that after MBB (P<0.05). Percentage of pain relief in the operation group at any time point postoperatively were significantly higher than that in the conservative group (P<0.01). The MacNab scores of 1 year follow-up in the operation group were higher than that in the conservative group. In addition, four separate newly identified anatomical variations of medial branch anatomy were observed and reported. CONCLUSION: Dorsal endoscopic rhizotomy is safe and effective for the facetogenic CLBP, and can achieve better clinical outcome than the conservative treatment.