Mechanical Discectomy and post-operative rehabilitation protocol for the treatment of contained lumbar disc herniation in young: a comparative study with laser discectomy
Low back pain (LBP) is an extremely common clinical condition, and is often considered as the most frequent cause of activity limitation and absence from work in young adult population [1,2]. Symptoms may arise from different anatomic sources, such as muscle, fascial structure, bone, joints and intervertebral disc. Therefore, the identification of the source of pain is essential to choose the appropriate therapy [3,4]. Radicular pain, defined as pain irradiated into the lower limb trough the course of a nerve root. It occurs when a nerve root is compressed, inflamed or damaged. The most frequent causative factor of radicular pain is lumbar disc herniation (LDH). It can be suspected during clinical examination evaluating reflexes, muscle strength, cutaneous sensitivity to touches, pinpricks and vibration, and with supine straight leg raise, Lasègue sign and crossed Lasègue sign, and can be confirmed using a magnetic resonance imaging (MRI) .
In recent years, the use of mini-invasive percutaneous decompression techniques are becoming even more common, and can be often performed as outpatient procedure [6,7]. The rationale of this procedure is that the removal of a small amount of disk nucleus may results is a significant reduction of intradiscal pressure [6,7]. Several different surgical techniques were described in last the forty years, as chemonucleolysis , nucleoplasty , laser-thermal nucleotomy  and mechanical decompression [11,12].
The purpose of this study is to compare the clinical outcome and quality of life of patients effected by contained LDH treated by using a mechanical disc decompression or treated by euthermic nucleotomy followed by a of post-operative rehabilitationprotocol.
Materials and Methods
2.1 Study Design
The study protocol was approved by our internal ethics board. We retrospectively analyzed data of patients that underwent percutaneous discectomy between January 2017 to June 2018. During the first part of the study period (FromJanuary 2017 to September 2018), patients were operated through Percutaneous Laser Disc Decompression (PLDD) (Discolux by Siad Healthcare), while during the second part of the study period, patients were operated through Automated Percutaneous Lumbar Discectomy (APLD). The same inclusion and exclusion criteria were adopted for both groups. Patients with a contained LDH affected by neurological sign of radicular irritation, aged between 18 and 55 years that didn’t clinically improved after 6 week of conservative therapy. Patients older then 55 years, with previous history of lumbar spine surgeries, with radiological finding od spinal canal or foraminal stenosis, spondilolysthesis or extruded/sequestered disc herniation were excluded from the study. A total of 167 patients met the inclusion criteria, there were 99 women (59.7%) and 68 men (40.3%), among the 222 patients that underwent percutaneous procedure for the treatment of LDH during the study period.
2.2 Surgical Protocol
All the surgeries were performed by the same senior author, in operating room under strictly sterility measure. A single dose of antibiotic was injected for prophylactic purpose. Patients were placed in prone position with a pillow below the ankle.A posterolateral approach, approximately 10 cm lateral to the midline was used as entry point. Lumbar disc level was verified pre-operatively with fluoroscopy. The C-arm was placed with a 45° of inclination to reproduce the “Scottie Dog” images. Then, the trocaris advanced under continuous fluoroscopy within the disc until it reach the anterior third in the lateral projection, and it’s approximately on the midline in the antero-posterior projection.The PLDD is an outpatient percutaneous procedure in which the disc material is not removed, while the nuceous pulposus is burned. For this study the Discolux system (By SiadHealthcare) was used. This system is based on a novel low temperature diode laser (Ho:YAG 2100 nm, 3.5W, 10Hz 420 Joule), that allow to burn the herniated disc without damaging the surrounding soft tissue. The APLD is an outpatient percutaneous procedure, and it’s based on Archimede’s principle of screw pomp. For this study we used the Deko System (By SinteaPlustek, Assago, Milan, Italy)
2.3 Post-Operative Care
After 10 days from the surgery, the patients started the daily rehabilitation protocol, from Monday to Friday for four weeks. During the first week the rehabilitation sessions are daily, while in the following weeks are on alternate days. In addition, during the weekend patients performed daily home exercise in accordance with the therapist. The rehabilitation protocol was performed in the same physiotherapy center by the same expert physiotherapist. It consist of hydrotherapy, TECAR-therapy, Pulsed Signal therapy, Neurofeedback therapy and cranio-sacral therapy.
2.4 Assessment Methods
Visual Analogue Scale (VAS) was used for pain measurement, while Oswestry Disability Index (ODI) was used to measure patients function disability. In addition, the short form of SF-12 was used to assess the quality of life. All the patients underwent the same surgical and rehabilitation protocol. Clinical assessment was performed 1 week, 1 month, 6 months and 1 year after surgery.
2.5 Statistical Analysis
Descriptive data were presented as mean value with standard deviation (SD). Pre-operative and post-operative VAS, ODI and SF-12 was performed using an unpaired t-test, a p-value < 0.05 was considered as statistically significant. Unpaired t-test was used to compare the outcome between the two groups of patients. In addition a Kaplan-Meier curve was performed to compare the success of the procedure, a revision or a reduction of VAS improvement > 50% were defined as failure.
3.1 Outcome in the APLD group
Three patients did not complete the rehabilitation protocol and four patients were lost to follow-up before one year, leaving 91 patients for the final analysis. The LDH was located at the L5-S1 level in 48 patients (52.7%), at the L4-L5 level in 38 patients (41.7%), at the L3-L4 level in 3 patients (3.3%) and at the L2-L3 level in 1 patient (1.1%). The mean follow-up was 14.2 months (SD +/- 1.8 months). There were no bleeding, spondylodiscitis or surgical site infection. A worsening of clinical condition was observed in 5 cases (5.5%), while a reoperation was necessary for three patients (3.3%).
The mean pre-operative VAS score was 7.2 (SD +/- 1.7), while the 1 month post-operative VAS score 2.9 (SD +/- 1.2) and the mean 1 year postoperative VAS score was 2.5 (SD +/- 1.6). The mean pre-operative ODI score was 34.8 (SD +/- 11.4), while the mean 1 month post-operative ODI score was 16.8 (SD 11.8) and the mean post-operative 1 year ODI score was 16.4 (SD 10.8). The mean pre-operative SF-12 score was 25.7 (SD 9.9), while the mean 1 month post-operative SF-12 score was 51.8 (SD 10.9) and the mean 1 year post-operative SF-12 Score was 49.8 (SD 11.1). A statistically significant improvement was observed between pre-operative VAS score and 1 month post-operative VAS score, and between pre-operative VAS score and 1 year post-operative VAS score (p < 0.05). A statistically significant improvement was observed between pre-operative ODI score and 1 month post-operative ODI score, and between pre-operative ODI score and 1 year post-operative ODI score (p < 0.01). A statistically significant improvement was observed between pre-operative SF-12 score and 1 month post-operative SF-12 score, and between pre-operative SF-12 score and 1 year post-operative SF-12 score (p < 0.01).
3.2 Outcome in the PLDD group
Two patients did not complete the rehabilitation protocol and three patients were lost to follow-up before one year, leaving 69 patients for the final analysis. The lumbar disc herniation was located at the L4-L5 level in 34 patients (49.3%), at the L5-S1 level in 29 patients (42%), at the L3-L4 level in 4 patients (5.8%) and at the L2-L3 level in the remaining 2 patients (2.9%). The mean follow-up was 16.2 months (SD +/- 2.1 months). There were no bleeding, spondylodiscitis or surgical site infection. A worsening of clinical improvement was observed in 6 cases (8.6%), while a reoperation was necessary for three patients (4.5%).
The mean pre-operative VAS score was 7.4 (SD +/- 1.8), while the 1 month post-operative VAS score 3.4 (SD +/- 1.4) and the mean 1 year postoperative VAS score was 3.7 (SD +/- 1.6).The mean pre-operative ODI score was 37.4 (SD +/- 12.8), while the mean 1 month post-operative ODI score was 19.8 (SD 12.3) and the mean post-operative 1 year ODI score was 18.9 (SD 11.3). The mean pre-operative SF-12 score was 27.8 (SD 9.6), while the mean 1 month post-operative SF-12 score was 48.3 (SD 11.4) and the mean 1 year post-operative SF-12 Score was 45.8 (SD 10.8). A statistically significant improvement was observed between pre-operative VAS score and 1 month post-operative VAS score, and between pre-operative VAS score and 1 year post-operative VAS score (p < 0.05). A statistically significant improvement was observed between pre-operative ODI score and 1 month post-operative ODI score, and between pre-operative ODI score and 1 year post-operative ODI score (p < 0.01). A statistically significant improvement was observed between pre-operative SF-12 score and 1 month post-operative SF-12 score, and between pre-operative SF-12 score and 1 year post-operative SF-12 score (p < 0.01).
3.3 Differences between the two groups
When the two groups of patients were compared, no statistically significant difference were observed for: % of patients lost to follow-up, gender, level of surgeries, pre-operative VAS, pre-operative ODI and Pre-operative SF-12. In addition no statistically significant differences were observed for the percentage of patients that showed a post-operative worsening of clinical conditions (p = 0.5032) or for the reoperation rate (p = 0.796). A detailed summary is showed in table 1. No statistically significant difference were observed for post-operative ODI (Figure 1), neither after 1 month (p = 0.1130), nor after 1 year (p = 0.1494). The mean post-operative VAS (Figure 2) was significant lower in APLD group both after 1 month (p = 0.0146) and after 1 year (p < 0.0001). The mean SF-12 score was significantly higher in APLD group both after 1 month (p = 0.0461) and after 1 year (p = 0.0259).
|Lost to follow-up||7 (7.1%)||5 (6.8%)||0.8304|
|Sex: Male||39 (42.8%)||29 (39.2%)||0.1691|
|Mean Age||42.3 years||41.8 years||0.5934|
|L5-S1||48 (52.7%)||34 (49.3%)||0.3848|
|L4-L5||38 (41.7%)||29 (42%)||0.7382|
|Worsening of clinical condition||5 (5.5%)||6 (8.6%)||0.5032|
|Reoperation||3 (3.3%)||3 (4.5%)||0.796|
Table 1: Demographic data of the two groups of patients.
Figure 1: comparison of pre-operative and post-operative mean values of ODI in APLD and PLDD groups.
Figure 2: comparison of pre-operative and post-operative mean values of VAS in APLD and PLDD groups.
Figure 3: comparison of pre-operative and post-operative mean values of SF-12 in APLD and PLDD groups.
In the last decades many different mini-invasive techniques were described for the treatment of contained lumbar disc herniation . Traditional open techniques reported poor results, with an high risk of recurrent sciatica and reherniation [14,15]. In the present study, we compared the results obtained with two different techniques, PLDD and APLD for the treatment of contained lumbar disc herniation. PLDD, is a technique based on the intradiscal pressure reduction caused by the nucleus pulposus vaporization. In order to obtain an appropriate effectiveness and avoid soft tissue damage, we used an Ho:YAGlaser with a 2100 nm wavelength. APLD was first introduced by Onik in 1985, and it is based on the mechanical aspiration of the disc material [16, 17]. In a recent systematic review performed by Hirsch et al. in 2009, APLD demonstrated to be effective to obtain pain relief and function improvement in selected patients .In the present study we demonstrate that both the minimally invasive techniques adopted were effective in reducing pain, improving function and quality of life of patients affected by contained LDH with a previous history of failed medical treatment. These results were obtained thanks to the strictly inclusion criteria during the surgical indications and thanks to the post-operative rehabilitation protocol. The group of patients treated with APLD showed a statistically significant reduction for post-operative VAS and for post-operative SF-12 when compared with PLDD. Another interesting results observed in this study was the low incidence of reoperation in both groups, respectively 3.3% in the APLD group, and 4.5 in the PLDD group. In addition, in no cases a discitis were observed. At our knowledge this is the first study that compare the outcome of patients with these two minimally invasive techniques.
The present study has several limitations. First, the cohort is limited and a higher number of patients could provide more detailed information about the differences in the outcome between the two techniques. Second, the follow-up duration is limited and a longer observation period could provide information about the longevity of the efficiency of the treatment. Third, the two groups of patients were consecutive and were non-randomly selected. Lastly, this is a retrospective study characterized by significant biases that could affect the selection of patients.
Considering the recent literature evidence, young patients with an history of low back pain affected by LDH in whom conservative therapy failed should be addressed to a minimally-invasive surgical procedure . In a recent systematic review on twenty-nine studies (sixteen randomized controlled trial and thirteen non randomized ), Kamper et al, that there is no differences in clinical outcomes when minimally invasive surgery is compared with conventional microdiscectomy for patients with sciatica due to LDH. Considering APLD, Manchikanti et al. , in a systematic review of nineteen observational studies, founded that more than 80% of patients showed positive results, but considering the paucity of long-term follow-up studies the efficiency of these technique was proved only in short and mid-term follow-up. Similar results were also observed by Patel et al. , that performed a systematic review of the literature on studies of PLDD, founded that the mean VAS score improved from 7.6 pre-operatively to a mean of 4.2 after 6-12 months.
In conclusion, minimally invasive techniques as APLD and PLDD, allow to obtain optimal results in term of pain reduction, and improving function and quality of life in appropriate selection of patients affected by low back pain and/or sciatica due to contained LDH. In addition, our results suggest that a post-operative rehabilitation protocol, could help to improve the outcome and to maintain.
 Hoy D, March L, Brooks P, Blyth F, Woolf A, Bain C, Williams G, Smith E, Vos T, Barendregt J, Murray C, Burstein R, Buchbinder R. The global burden of low back pain: estimates from the Global Burden of Disease 2010 study. Ann Rheum Dis. 2014 Jun;73(6):968-74. doi: 10.1136/annrheumdis-2013-204428.
 Hoy D, Bain C, Williams G, March L, Brooks P, Blyth F, Woolf A, Vos T, Buchbinder R. A systematic review of the global prevalence of low back pain. Arthritis Rheum. 2012 Jun;64(6):2028-37. doi: 10.1002/art.34347.
 Amirdelfan K, McRoberts P, Deer TR. The differential diagnosis of low back pain: a primer on the evolving paradigm. Neuromodulation. 2014 Oct;17 Suppl 2:11-7. doi: 10.1111/ner.12173.
 Sembrano JN, Polly DW Jr. How often is low back pain not coming from the back? Spine (PhilaPa 1976). 2009 Jan 1;34(1):E27-32. doi:10.1097/BRS.0b013e31818b8882.
 Allegri M, Montella S, Salici F, Valente A, Marchesini M, Compagnone C, Baciarello M, Manferdini ME, Fanelli G. Mechanisms of low back pain: a guide for diagnosis and therapy. Version 2. F1000Res. 2016 Jun 28 ;5.pii: F1000 Faculty Rev-1530. eCollection 2016.
 Kamper SJ, Ostelo RW, Rubinstein SM, Nellensteijn JM, Peul WC, Arts MP, vanTulder MW. Minimally invasive surgery for lumbar disc herniation: a systematicreview and meta-analysis. Eur Spine J. 2014 May;23(5):1021-43. doi: 10.1007/s00586-013-3161-2.
 Alvi MA, Kerezoudis P, Wahood W, Goyal A, Bydon M. Operative Approaches for Lumbar Disc Herniation: A Systematic Review and Multiple Treatment Meta-Analysis of Conventional and Minimally Invasive Surgeries. World Neurosurg. 2018 Jun;114:391-407.e2. doi: 10.1016/j.wneu.2018.02.156.
 Nordby EJ, Wright PH. Efficacy of chymopapain in chemonucleolysis. A review. Spine (Phila Pa 1976). 1994 Nov 15;19(22):2578-83.
 Eichen PM, Achilles N, Konig V, Mosges R, Hellmich M, Himpe B, Kirchner R. Nucleoplasty, a minimally invasive procedure for disc decompression: a systematic review and meta-analysis of published clinical studies. Pain Physician. 2014 Mar-Apr;17(2):E149-73.
 Patel N, Singh V. Percutaneous Lumbar Laser Discectomy: Literature Review and a Retrospective Analysis of 65 Cases. Photomed Laser Surg. 2018 Oct;36(10):518-521. doi: 10.1089/pho.2018.4460.
 Manchikanti L, Singh V, Falco FJ, Calodney AK, Onyewu O, Helm S 2nd, Benyamin RM, Hirsch JA. An updated review of automated percutaneous mechanical lumbar discectomy for the contained herniated lumbar disc. Pain Physician. 2013 Apr;16(2 Suppl):SE151-84.
 Manchikanti L, Singh V, Calodney AK, Helm S 2nd, Deer TR, Benyamin RM, Falco FJ, Hirsch JA. Percutaneous lumbar mechanical disc decompression utilizing Dekompressor®: an update of current evidence. Pain Physician. 2013 Apr;16(2 Suppl):SE1-24.
 Ong D, Chua NH, Vissers K. Percutaneous Disc Decompression for Lumbar Radicular Pain: A Review Article. Pain Pract. 2016 Jan;16(1):111-26. doi: 10.1111/papr.12250. Epub 2014 Oct 29.
 1. Carragee EJ, Han MY, Suen PW, et al. Clinical outcomes after lumbar discectomy for sciatica: the effects of fragment type and anular competence. J Bone Joint Surg Am. 2003;85 A:102–108. 2.
 Dewing CB, Provencher MT, Riffenburgh RH, et al. The outcomes of lumbar microdiscectomy in a young, active population: correlation by herniation type and level. Spine. 2008;33:33–38.
 Onik G, Helms CA, Ginsberg L, et al: Percutaneous lumbar diskectomy using a new aspiration probe. AJNR 6:290-293, 1985; A JR 144:1137-1142, 1985
Onik G, Helms CA, Ginsberg L, et al: Percutaneous lumbar diskectomy using a new aspiration probe: porcine and cadaver model. Radiology 155:251-252, 1985
Singh V, Falco FJ, Benyamin RM, Manchikanti L. Automated percutaneous lumbar discectomy for the contained herniated lumbar disc: a systematic assessment of evidence. Pain Physician. 2009 May-Jun;12(3):601-20. Review. PubMed PMID: 19461826.
 Dewing CB, Provencher MT, Riffenburgh RH, Kerr S, Manos RE. The outcomes of lumbar microdiscectomy in a young, active population: Correlation by herniation type and level. Spine (PhilaPa 1976) 2008;33(1):33–38. doi: 10.1097/BRS.0b013e31815e3a42  Kamper SJ, Ostelo RW, Rubinstein SM. et al. Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis. Eur Spine J. 2014;23(5):1021–1043.