Modified Percutaneous Lumbar Foraminoplasty
and Percutaneous Endoscopic Lumbar
Discectomy: Instrument Design, Technique
Notes, and 5 Years Follow-up
Authors: Li Zhen-zhou 
Published: October 2019

Background: Conventional percutaneous endoscopic lumbar discectomy (PELD) with an “insideoutside” 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.
Result: 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.
Cohort Study
Modified Percutaneous Lumbar Foraminoplasty
and Percutaneous Endoscopic Lumbar
Discectomy: Instrument Design, Technique
Notes, and 5 Years Follow-up
From: The First Affiliated
Hospital of Chinese PLA’s
General Hospital
Beijing, China
Address Correspondence:
Zhen-zhou Li, M.D.
Associate Chief Surgeon
The First Affiliated Hospital
of Chinese PLA’s General
Hospital, Department of
Orthopedic Surgery
No. 51, Fucheng Road
Haidian district
Beijing, Beijing 100048
China
86 1068989322
E-mail:
dr_lizhenzhou@163.com
Disclaimer: There was
no external funding in
the preparation of this
manuscript.
Conflict of interest: Each
author certifies that he or
she, or a member of his or
her immediate family, has
no commercial association
(i.e., consultancies,
stock ownership, equity
interest, patent/licensing
arrangements, etc.) that
might pose a conflict of
interest in connection with
the submitted manuscript.
Manuscript received:
08-10-2015
Revised manuscript received:
12-28-2015
Accepted for publication:
03-28-2015
Free full manuscript:
www.painphysicianjournal.
com
Zhen-zhou Li, MD, Shu-xun Hou, MD, Wei-lin Shang, MD, Ke-ran Song, MD, and
Hong-liang Zhao, MD
www.painphysicianjournal.com
Pain Physician 2017; 20:E85-E98 • ISSN 2150-1149
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