Surgical Outcome of Fusion in Recurrent Lumbar Disc Herniation

Background Data: Recurrent lumbar disc herniation means re-herniation of disc on the same site and at the same level where a previous discectomy had been performed: recurrent lumbar disc herniation occurs in 7% to 24% of patient underwent discectomy. Tow mean surgical options after reherniated lumbar disc are revision discectomy alone or revision discectomy with fusion discectomy alone in recurrent lumbar disc herniation may not be an efficient treatment without fusion. Objective: To evaluate the efficacy and safety of revision discectomy with fusion in management of recurrent lumbar disc. Study Design: Retrospective study reviewed all patient underwent revision discectomy with fusion, they were 40 patients operated for recurrent lumbar disc from September 2014 to April 2018 in Al-Azhar University Hospital Damietta. Pre- and post-operative data collection and analysis of the outcome were completed based on the “Japanese Orthopedic Association score” (JOAs), and radiographic follow-up. Patients and Methods: 40 patients (30 male and 10 female) underwent revision discectomy with fusion as surgical management for reherniated lumbar disc from September 2014 to April 2018. All patients presented with low back pain and radicular pain with mean duration of 18 months. The patients were investigated by standard plain X-ray CT SCAN and MRI of the lumbar spine. All patients had a discectomy and postero-lateral fusion in revision surgery. These patients followed post operatively clinically for improving pain and neural function, and radiologically for disc removal stabil-ity and fusion. Results: The age ranged from 30 to 60 years, mean age was 45 years, male to female ratio 3:1. Follow-up ranged from 18 - 30 months with a mean follow-up 24 months. 30 patients had an excellent outcome, 6 patients had a good outcome, 2 patients had a fair outcome, and 2 patients had a poor outcome. Conclusion: Recurrent lumbar disc herniation occurs in 7% to 24% of patient underwent discectomy. Revision surgery when indicated can be done by various techniques. Revision discectomy with fusion for reherniated lumbar disc is effective and safe with confident results.


Introduction
Recurrent disc herniation is defined as disc herniation seen at the same level after a painless period of at least 6 months following the first surgery. Recurrent herniation may be on the same or opposite side [1] [2].
Risk of unfavourable outcomes like obesity, diabetes, vibration workers, drivers and psychological factors should be taken into consideration before surgery for the first instance which increases the incidence of recurrence [3].
The optimal treatment of recurrent disc herniation is still controversial. Some surgeons choose simple discectomy again, while some surgeons advocate fusion surgery. Because recurrent disectomy (ipsilateral/contralateral) requires more disc and posterior spinal component removal (lamina and/or facet joint), recurrent discectomy will increase the likelihood of segmental instability and due to scar tissue; dural tear, and nerve injuries may be greater at simple re-discectomies, some surgeons suggest fusion surgery at first recurrent, regardless of whether instability [5].
The aim of this study was to evaluate the efficacy and safety of fusion in reherniated lumbar disc surgery.

Patients and Methods
This retrospective study was carried out on 40 patients 30 male and 10 female age ranged from 30 to 60 years with mean age 45 years who underwent revision discectomy with fusion for reherniated lumbar disc from September 2014 to April 2018 in Neurosurgery Department Al-Azhar University Hospital New Damietta Egypt.
Inclusion criteria: 1) At least 6 months of pain relief after previous disc surgery.
2) The presence of recurrent disc herniation and radicular pain not respond to conservative treatment.
3) Reoperation in the early postoperative period for infections.
The study was approved by the local ethical committee and informed consent was obtained from participating patients. Data collection was extracted from hospital records (patient admission sheet medical records imaging studies operative and postoperative details and progressive notes).

Preoperative Assessment
All patients were subjected to careful history taking general and neurological examination. All patients had pre operative lumbo-sacral X-ray A-P and dynamic views flexion extension and oblique and MRI examination (Figures 1-3).   were evaluated carefully and confirmed that recurrence rate increased with heavy activities and chronic diseases as diabetes.

Operative Technique
Surgery was performed after induction of general anesthesia with the patient placed in prone position and the spine flexed. All patients were positioned prone on frame or rolls to avoid abdominal compression and hence reduce venous congestion. Skin incision was given over the previous operative site after full preparation. After muscle dissection soft tissue was cleaned from facet in a lateromedial direction. The medial edge of facet defined with curate and the plane between the dura and the medial facet was appreciated and enlarged.
Medial facectetomy was completed. The nerve root identified after removing the remaining ligamentum flavum. Nerve root was retracted and the discectomy completed. Posterolateral fusion and trans-pedicular screw fixation were performed.
Closure was then done in a routine fashion after insertion of a subcutaneous suction drain (Figure 4 & Figure 5).
Clinical symptoms were evaluated pre and post-operatively according the criteria of the "Japanese Orthopedic Associations core" (JOA) [6].
Japanese Orthopaedic Association (JOA) score assessment of the surgical treatment of low back pain (Tables 1-4).       Surgical outcome assessed according to the recovery rate as described by Hirabayashi et al. [6] ( ) ( ) post operative score preoperative score Recovery rate % 100 Normal score 29 preoperative score The results were classified into a four-grade scale: excellent improvement > 90%, good 75% -89%, fair 50% -74% and poor < 49%. Differences in preoperative symptoms and post-operative outcomes were statistically analyzed. The statistical significance was set at a P-value.

Results
Forty patients with recurrent lumbar disc were surgically treated 30 male 75% and 10 female 25% the mean age at the time of surgery was 45 years range from 30 -60 years. The recurrent time to the primary surgery ranged from 9 -24 months with a mean duration of 17 months ( Table 5). The most common complaint was low back pain and radicular pain. Overall JOA score of the patients showed improvement, moving from (6.54 points) before surgery to (12.65 points) at the final follow-up. Low back pain, radicular pain ability to walk, straight leg raising, and manual muscle testing valuated by JOA score are shown in Table 6.
No major complications were observed. There was one case with superficial infection and they had received parental antibiotics with no need for surgical intervention. Five patients had dural tears which were repaired intra-operatively with no subsequent sequelae (Table 8).

Discussion
Reherniated lumbar is an important disease which seen commonly. The rate of recurrent disc herniation after lumbar discectomy is 5% to 15% [5]. So that, recurrent lumbar disc herniation (RLDH) is a major cause of surgical failure [7], the recurrent disc herniation is the major cause of the failed back surgery syndrome [8]. The optimal surgical approach (simple discectomy with or without fusion of the affected segment) for recurrent disc herniation remains a subject of controversy [9] [10].    For this reason, its accurate management is of great importance. In the modern LDH surgery, various techniques have been identified and applied since the Love's operation was identified [11].
There is a number of case series describing outcomes after either preoperative discectomy or postoperative discectomy combined with fusion [12].
In the present study, we done revision discectomy with fusion this technique resulted in satisfactory results. to have better outcomes than those with disc excision alone [13] in the present study which conducted on 40 patients with first time recurrent lumbar disc herniation after exclusion of those with cauda equine syndromes, and patients with spondylolisthesis. After a mean follow-up of 18 months, the mean postoperative recovery rate was 85% and the satisfactory rate was 90%.
As regards the complications in the present study was found that 5 patients Tsai-Sheng et al. [10] stated that, the optimal surgical approach (simple discectomy with or without fusion of the affected segment) for recurrent disc herniation remains a subject of controversy [10], but in the present study it was found that revision discectomy with fusion has several advantages in the surgical outcomes, specifically, lumbar fusion which minimizes segmental motion, immobilizes the spine decrease mechanical stresses across the degenerated disc space, and may reduce reherniated disc at the same level.

Conclusion
Fusion in re-herniated lumbar disc remains a controversial decision. But the surgical outcome is more satisfactory when revision discectomy is done with fusion rather than by using discectomy alone and this confirmed in our study revision discectomy with fusion in reherniated lumbar disc is a worthy choice according to our study.