Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Minimally invasive surgical techniques for the therapy of far lateral disc herniation in middle-aged and elderly patients

Minimally invasive surgical techniques for the therapy of far lateral disc herniation in... COMPUTER ASSISTED SURGERY 2019, VOL. 24, NO. S1, 13–19 https://doi.org/10.1080/24699322.2018.1557897 RESEARCH ARTICLE Minimally invasive surgical techniques for the therapy of far lateral disc herniation in middle-aged and elderly patients Weijian Ren, Yu Chen and Liangbi Xiang Liaoning University of Traditional Chinese Medicine, Shenyang, People’s Republic of China KEYWORDS ABSTRACT Far lateral disc herniation, To examine the clinical results of different minimally invasive techniques for the therapy of far instability, minimally lateral disc herniation in middle-aged and elderly patients. An endoscopic approach (percutan- invasive, radicuar pain eous endoscopic lumbar discectomy; PELD), MIS-TLIF combined with contralateral translaminar screw (MIS-TLIF CTS), and MIS-TLIF combined with bilateral pedicle screws (MIS-TLIF BPS) were evaluated via a retrospective chart review. Data from 74 consecutive middle-aged and elderly patients with far lateral disc herniation were analyzed. All patients underwent surgery; 19 with PELD, 24 with MIS-TLIF CTS, and 31 with MIS-TLIF BPS. Clinical data included the length of the incision, duration of the operation, estimated blood loss, hospitalization time, operation cost, recurrence rate, and fusion rate. Preoperative and postoperative patient outcomes including the VAS, ODI scores and MacNab criteria were assessed and recorded. The mean follow-up time was 26.4 months (range from 14 to 46 months). Compared with the internal fixation groups, the length of the incision, duration of operation, estimated blood loss, and hospitalization time were obviously lower in the PELD group. The difference in operation cost among the three methods was statistically significant. The postoperative VAS scores for LBP and LP decreased sig- nificantly as compared with those recorded preoperatively. The postoperative ODI scores were lower than those recorded preoperatively. MacNab criteria rating excellent, good and fair results were in 27, 37 and 10 patients, respectively. Conclusion: PELD, MIS-TLIF CTS, and MIS-TLIF BPS are all effective minimally invasive techniques for the therapy of single segment far lateral lum- bar disc herniation in middle-aged and elderly patients. PELD had a shorter operation time and less surgical trauma, being a less invasive and more economical method; however, there was no recurrence of disc herniation after fixation. Compared with MIS-TLIF BPS, MIS-TLIF CTS obtained a similar clinical effect and certain costs were saved. Introduction tissue, lamina, but also directly expose the far lateral protruding disc [5, 6]. As a result of its minimal surgical With the development of society and improvements in trauma, paraspinal lateral surgeries such as PELD, MIS- medical technology, the aging population is becoming TLIF CTS, and MIS-TLIF BPS have been widely used in increasingly apparent [1]. The facet joints and interver- recent years [7, 8]; however, the surgical comparison of tebral discs play an important role in maintaining exer- these three approaches in middle-aged and elderly cise in old age. Lumbar and lower extremity pain in patients with far lateral disc herniation is still lacking. middle-aged and elderly patients has been shown to The purpose of this study is to examine the necessity mainly originate from lumbar disc herniation [2]. The of internal fixation and compare the clinical results of far lateral lumbar disc herniation (FLDH) accounts for different minimally invasive approaches for treatment 0.7–11% of all disc herniation [3].The prolapsed disc of FLDH in middle-aged and elderly patients. often compresses the exiting root and ganglion, lead- ing to severe radicular pain. The traditional posterior midline approach, paraspinal and endoscopic Materials and methods approaches are common surgical approaches for FLDH [4]. Typically, the minimally invasive paraspinal Data were collected from consecutive patients treated approaches not only minimize the damage to soft by surgery at the General Hospital of Shenyang CONTACT Weijian Ren renweijian2009@163.com Liaoning University of Traditional Chinese Medicine, Number 79 Chongshan Eastern Road, Huanggu District, Shenyang, Liaoning, 110847, People’s Republic of China. 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 14 W. REN ET AL. Military Region between March 2010 and December The MIS-TLIF CTS group 2016. The enrolled criteria were illustrated below: Patients received general anesthesia in the prone pos- patients who (1) had one segment far lateral disc her- ition, and the localization of target segment was niation, lower extremity symptoms, and lower back guided by preoperative C-arm which parallel to the pain; (2) demonstrted not relieving or aggravating upper end plate. A 30-mm vertical skin incision was after 3 months of conservative treatment; (3) pre- performed approximately 1–2 cm lateral to the midline sented with symptoms that were consistent with sin- of the spine, followed by transmuscular dilatation gle segment lumbar disc herniation on MRI and/or CT. between the polyfissure and longissimus muscles. The The criteria of exclusion were illustrated below: working channel was inclined approximately 5–10 patients who (1) had multi-segment lumbar interverte- toward the disc space to localize the disc prolapse bral disc herniation; (2) had undergone spinal surgery; (21). The surgical methods were as follows: decom- or (3) had a history of fractures, tumors, infections, or pression, excision of the articular process and part of other spinal diseases. These patients corresponded to the yellow ligament; exposure of the exiting nerve 4.6% of those who experienced lumbar disc surgery at root; opening the exiting nerve root canal; discectomy; that time. Forty-one patients were men and 33 were end plate treatment; and intervertebral bone graft and women, aged between 57 and 82 years old (mean cage implantation. The ipsilateral pedicle screws were 63.3). There were 26 cases in L5/S1 level, 32 in L4/5 positioned directly. For the purpose to keep the bal- level, 15 in L3/4 level, and 1 in L2/3 level. ance of spine, the translaminar screw was placed Comorbidities included coronary heart disease, dia- along the base of the superior spinous process and betes, and tobacco use(Table 1). Clinical data included contralateral lamina to opposite facet joint(Figure 2). the length of the incision, duration of operation, esti- mated blood loss, hospitalization time, operation cost, The MIS-TLIF BPS group recurrence rate, and fusion rate. Outcomes included Patients underwent the similar surgical procedures, the VAS score for LBP and LP and the ODI score pre- and the contralateral percutaneous pedicle screws operatively and at 1-week and 12-months postopera- were inserted under the guidance of a C tively, which were defined as excellent, good, fair or arm(Figure 3). poor based on the MacNab criteria. The study was approved by the Ethics Committee of the General Statistical analysis Hospital of Shenyang Military Region. SPSS 19.0 was used for statistical analysis. The com- parison was demonstrated as follows: homogeneity of Surgical techniques variance and normal distribution using an independ- ent sample t-test, and variance of arrhythmia and nor- The PELD group mal distribution using a t-test. Attribute data were The PELD was performed under local anesthesia in the analyzed with v test. A p value< .05 was considered prone position. Firstly, location of body surface inci- statistically significant. sion was guided by C-arm, and a 0.7-mm guiding wire was inserted via the anaesthetic puncture needle. A Results double-channel eccentric guide rod with an outer diameter of 6 mm was placed toward the prolapse, The mean follow-up time was 26.4 months (range and the dilator was inserted into the extraforaminal from 14 to 46 months). The three groups had equiva- lumbar disc herniation. An inner diameter of 6.5 mm lent average age, gender distribution, level distribu- surgical working tube with a beveled opening was tion, and comorbidities. Compared with the internal then pushed ventrally over the dilatator to protect the fixation groups, the length of the incision, duration of nerve roots. The beveled opening of the tube was operation, estimated blood loss, and hospitalization adjusted and pushed toward the prolapse. Secondly, time were obviously lower (p< .05) in the PELD group. nerve root decompression was performed under grav- The difference in operation cost was statistically sig- ity-controlled liquid flow and visual control. In add- nificant; PELD was the least, followed by MIS-TLIF CTS, ition, a high frequency semi-active flexible bipolar and then MIS-TLIF BPS(Table 2). The postoperative VAS probes were used for coagulation hemostasis and soft scores for LBP and LP decreased significantly as com- tissue formation(Figure 1). pared with those recorded preoperatively. The COMPUTER ASSISTED SURGERY 15 postoperative ODI scores were lower than those necessity of internal fixations. For elderly patients with recorded preoperatively (p< .05), with the postopera- severe osteoporosis or other diseases, who could not tive LBP in the PELD group being significantly lower tolerate general anesthesia, we used PELD to remove than others. In addition, there was no significant dif- the prolapse under local anesthesia. Those compli- cated with degenerative instability, spondylolisthesis, ference in the ODI or VAS scores according to MacNab criteria among the three groups postoperatively isthmus, or giant disc calcification, we performed MIS- (p> .05). MacNab criteria rating excellent, good and TLIF CTS or MIS-TLIF BPS. fair results were in 27, 37 and 10 patients, In the present study, the length of the incision, dur- ation of the operation, estimated blood loss, and hos- respectively(Table 3). The PELD group had two cases of postoperative pitalization time in the PELD group were apparently lower than other groups, reflecting that PELD for recurrence, and the other two groups had no recur- rence; however, there was no significant difference patients with FLDH has a lot of advantages. Recent (p> .05). There was also no significant difference in studies have also documented good results by PELD the fusion rate at 1-year follow-up between the two for FLDH [16]. Lower blood loss and a shorter oper- ation time appear to be the benefits of a PELD surgi- groups with internal fixations. Incision infection occurred in 2 cases in all three groups, but no other cal approach, resulting in little soft tissue damage due complications occurred. to the gravity-controlled liquid flow and the applica- tion of high frequency semi-active flexible bipolar probes. Guiding by lens optics under controlled liquid Discussion not only enables clear visual environment but also Far lateral disc herniation (FLDH) is also known as for- reduces hemorrhage. The bipolar probes can be aminal, intraforaminal, or extreme lateral disc hernia- applied in the immediate vicinity of neural structures tion, which is defined as a disc herniation or prolapse and avoid intraoperative bleeding [17]. Patients with that resides lateral and beneath to the upper and FLDH who undergo PELD can recover faster and walk lower pedicles and compresses the exiting root and down early. The reasons are as follows: (1) faster ganglion [10, 11]. FLDH rarely causes compression of recovery of lower waist soft tissue after PELD with lit- the dural sac, cauda equina and dysfunction of the tle tissue resection and almost no injury to the bony bowel and bladder. In the current research, the aver- structure helps to strengthen the waist and enable age patient age was 63.3 years old (range from 57 to earlier occupational and athletic levels of activity; (2) 82), which is consistent with that in previous studies less trauma reduces the theoretical probability of poor [11] and shows that FLDH predominately occurs in wound healing and fat liquefaction as compared with middle-aged and elderly patients. Although conserva- traditional surgery; and (3) rehabilitative measures are tive treatment can occasionally be effective, surgery is not necessary. Kambin et al. reported that a few usually required [12]. Various surgical approaches have patients presented with postoperative hip or leg caus- been performed for the operative treatment of FLDH. algia secondary to immature operation of the dorsal With the improvement and popularity of minimally root ganglion; however, no patients experienced caus- invasive spine technology, PELD, MIS-TLIF CTS, and algia in the present study and the clinical effect was MIS-TLIF BPS have become widely used as ameliora- satisfactory. As for the reasons; exact preoperative tive treatments [13]. Compared with traditional mid- measurement is necessary and the manipulation of line approaches, these three minimally invasive PELD has a prolonged learning curve. Firstly, in most techniques are implemented with a mini-incision, patients presented with FLDH, the outreaching angle require smaller muscle soft tissue dissection, supraspi- and the distance between the incision and the midline nal interspinous ligaments and spinous process are needs to be measured. The purpose was to make pos- retained. One previous study reported that PELD has sible tangential reaching of the sagittal and coronal shown comparable results to the standard surgery localization of the prolapse. Secondly, the recognition [14]; however, another study reported that PELD in of the shape and orientation of the disc, ligaments, elderly patients had a higher reoperation rate during nerve, and vessels plays a vital role in the endoscopic the first 3.4 years of follow-up than traditional discec- environment; and continuing improvement of endo- tomy [15]. Due to this discrepancy, the present study scopic instruments enables a wider and more efficient compared the clinical results of PELD, MIS-TLIF CTS, decompression than ever. Thirdly, the degree of intra- and MIS-TLIF BPS for the treatment of FLDH in mid- operative decompression mainly depends on the dle-aged and elderly patients and examined the range of the fluid-controlled nerve root motion and 16 W. REN ET AL. Table 1. Patient baseline characteristics. A(N¼ 19) B(N¼ 24) C(N ¼ 31) P Age, y 64.7 ± 7.3 64.1 ± 6.3 63.9 ± 6.4 0.974 55–59 60–69 70 55–59 60–69 70 55–59 60–69 70 6 9 4 8 10 6 10 14 7 0.997 Gender n (%) Male 10 14 17 0.929 Female 9 10 14 Level n (%) 0.681 L2/3 1 0 0 L3/4 4 4 7 L4/5 9 11 12 L5/S1 5 9 12 Comorbidity type (%) 0.992 Diabetes 4 5 7 Coronary artery disease 6 7 8 Tobacco use 6 6 7 Table 2. Surgical outcomes. A(N ¼ 19) B(N¼ 24) C(N¼ 31) P(AB) P(AC) P(BC) length of incision, mm 7.7 ± 1.1 33.2 ± 2.6 34.1 ± 2.0 <0.05 <0.001 0.172 Duration of operation, min 97.1 ± 9.6 163.9 ± 9.5 167.2 ± 8.2 <0.001 <0.001 0.175 Estimated blood loss, mL 14.2 ± 6.9 141.3 ± 18.7 147.4 ± 19.7 <0.001 <0.001 0.244 hospitalization time, d 5.2 ± 0.9 10.8 ± 1.3 11.2 ± 1.2 <0.001 <0.001 0.237 operation cost, CNY 23001.1 ± 2426.2 51164.3 ± 5228.7 65805.6 ± 2886.3 <0.001 <0.001 <0.001 recurrence rate 11% 0 0 fusion rate – 100% 100% Table 3. Pre- and postoperative LP VAS score, ODI score and Macnab criteria assessment. A B C P(AB) P(AC) P(BC) VAS(BP) Preoperative 4.7 ± 1.1 4.9 ± 1.1 5.0 ± 1.0 0.692 0.355 0.594 1w postoperative 1.3 ± 0.5 2.8 ± 1.1 3.1 ± 1.0 <0.001 <0.001 0.333 1y postoperative 0.7 ± 0.5 1.2 ± 0.5 1.4 ± 0.7 <0.05 <0.001 0.227 VAS(LP) Preoperative 7.7 ± 0.9 7.8 ± 0.7 7.5 ± 0.9 0.663 0.508 0.209 1w postoperative 2.5 ± 0.5 2.5 ± 0.5 2.6 ± 0.6 0.868 0.382 0.444 1y postoperative 1.4 ± 0.8 1.5 ± 0.6 1.5 ± 0.6 0.858 0.754 0.878 ODI Preoperative 76.8 ± 6.7 74.3 ± 6.5 76.0 ± 6.9 0.218 0.671 0.364 1w postoperative 27.9 ± 2.7 26.5 ± 3.5 26.4 ± 3.6 0.131 0.109 0.941 1y postoperative 23.6 ± 3.2 22.9 ± 3.6 22.8 ± 3.6 0.508 0.442 0.944 Macnab criteria assessment .986 Excellent 7 9 11 Good 10 12 15 Fair 2 3 5 Poor 0 0 0 the patients’ expression of leg pain relief. As a result, scores at 1-week and 12-months post-surgery. adequate exposure and decompression could be Postoperative LBP in the PELD was significantly lower obtained and causalgia was avoided. than the others. The difference in cost among the three groups was In terms of neurofunctional recovery, the postop- statistically significant. The main reason for the lower erative ODI scores were significantly lower than cost of PELD is that the surgery is performed under those recorded preoperatively, indicating that min- local anesthesia and does not implant internal fixa- imally invasive surgeries can restore nerve function tions. The appraisal of the spend of internal fixtures and provide relief from the radiating pain. In the demonstrated that the application of MIS-TLIF CTS for present study, endoscopic decompression, nucleus one level fusion increased the spend by nearly 20% as pulposus excision, and decompression of the exiting compared with PELD. In terms of cost savings, a nerve root canal in the PELD group were similar to shorter hospitalization time also played a key role. the procedures in the MIS-TLIF CTS and MIS-TLIF The present data show that the postoperative VAS BPS groups. scores for LBP and LP decreased significantly com- Moreover, there were no statistically differences in pared with those recorded preoperatively; and all MacNab criteria and postoperative ODI scores among three minimally invasive operations had reduced VAS the three groups, demonstrating that the function of COMPUTER ASSISTED SURGERY 17 Figure 1. a typical case of PELD. Notes: (A) coronal CT shows L5/S1 right FLDH. (B) sagittal MRI shows L5/S1 FLDH. (C) and (D) intraoperative channel X-ray images. (E) and(F)Exposure of exiting nerve root. Figure 2. A typical case of MIS-TLIF CTS. Notes: (A) CT shows L4/5 left FLDH. (B) sagittal MRI shows L4/5 FLDH. (C) and (D) X-ray images demonstrate permanent position after 1 year.(E) and (F) coronal CT images after 1 year. these approaches in the therapy of middle-aged and that postoperatively scoliosis occurs more frequently elderly patients with FLDH is relatively comparable. in unilateral than bilateral groups [19]; however, the The main goal of the implant is to fix the spine and scoliotic patients did not have obvious clinical symp- ensure bone graft fusion; thus, the fusion rate is the toms in recent researches. To avoid the occurrence of most important index to evaluate. Bridwell et al., intro- scoliotic deformities, the patients with FLDH were duced the four grading criteria of radiographic fusion treated with MIS-TLIF CTS or MIS-TLIF BPS. Although [18]; both grades I and II are considered radiographic there exists a difference in the operation cost, the dif- signs of solid fusion. Previous studies have showed ference of fusion rate was not significantly different 18 W. REN ET AL. Figure 3. A typical case of MIS-TLIF BPS. Notes: (A) coronal CT shows L5/S1 right FLDH. (B) sagittal MRI shows L5/S1 FLDH. (C) and (D) X-ray images demonstrate permanent position after 1 year.(E)coronal and(F)sagittal CT images after 1 year. between the two groups at 1-year follow-up. Best NM invasive and more economical method; however, there et al., also reported that there were no apparent dif- was no recurrence of disc herniation after fixation. ferences in range of motion, fixation stiffness, or Compared with MIS-TLIF BPS, MIS-TLIF CTS obtained a multi-directional activities between the combination of similar clinical effect and certain costs were saved. unilateral pedicle screws and the translaminar screw and bilateral pedicle screw fixation [20]. Funding The PELD group had two cases of postoperative This work was supported by the Foundation of the Liaoning recurrence, which were revised by MIS-TLIF CTS; never- Province Doctor Startup Fund [201601389], the State Key theless, the difference in the recurrence rate was not Laboratory of Robotics [2017-O01], the Open Project statistically significant. However, there was no recur- Program of the State Key Lab of CAD&CG [A1718], the Open rence of disc herniation after internal fixations. There Project Program of the State Key Laboratory of Trauma, Burn were two cases of incision infection in all three groups, and Combined Injury [SKLKF201705] and the State Key which were cured by conservative treatment. Laboratory of Materials Processing and Die & Mould Technology [P2018-011]. There were many limitations in the current study. Firstly, this is a retrospective study with a small sample size; an additional multicenter and prospective study References with a larger sample is needed. Secondly, patient [1] The World Population Prospects. 2015 Revision.at selection has some limitations; multifocal lumbar disc <http://esa.un.org/unpd/wpp/Publications/Files/Key_ herniation needs further research. Thirdly, the included Findings_WPP_2015.pdf> studies were short- or medium-term. Long-term [2] Goldring MB, Goldring SR. Osteoarthritis. J Cell follow-up periods of the three methods should be Physiol. 2007;213:626–634. evaluated in the future. [3] Kim DG, Eun JP, Park JS. New diagnostic tool for far lateral lumbar disc herniation: The clinical usefulness of 3-Tesla magnetic resonance myelography compar- Conclusion ing with the discography CT. J Korean Neurosurg Soc. 2012;52:103–106. PELD, MIS-TLIF CTS, and MIS-TLIF BPS were all effective [4] Blamoutier A. Surgical discectomy for lumbar disc minimally invasive methods for the therapy of single herniation: surgical techniques. Orthop Traumatol segment far lateral lumbar disc herniation in middle- Surg Res. 2013;99:S187–S196. aged and elderly patients. PELD had a shorter [5] Quaglietta P, Cassitto D, Corriero AS, et al. Paraspinal operation time and less surgical trauma, being a less approach to the far lateral disc herniations: COMPUTER ASSISTED SURGERY 19 retrospective study on 42 cases. Acta Neurochir. 2005; [14] Kim CH, Chung CK, Park CS, et al. Reoperation rate 92:115–119. after surgery for lumbar herniated intervertebral disc [6] Lee JS, Woo JY, Jang JS, et al. Combined interlaminar disease: nationwide cohort study. Spine 2013;38: and paraisthmic approach for co-existing intracanal 581–590. and foraminal lesion. Korean J Spine. 2015;12: [15] Kim CH, Chung C, Choi KY, et al. The selection of 256–260. open or percutaneous endoscopic lumbar discectomy [7] Sethi A, Lee S, Vaidya R. Transforaminal lumbar inter- according to an age cut-off point: national-wide body fusion using unilateral pedicle screws and a cohort study. Spine 2015;40:E1063–E1070. translaminar screw. Eur Spine J. 2009;18:430–434. [16] Jang JS, An SH, Lee SH. Transforaminal percutaneous [8] Wang Y-P, An J-L, Sun Y-P, et al. Comparison of out- endoscopic discectomy in the treatment of foraminal comes between minimally invasive transforaminal and extraforaminal lumbar disc herniations. J Spinal lumbar interbody fusion and traditional posterior lum- Disord Tech. 2006;19:338–343. bar intervertebral fusion in obese patients with lum- [17] Ruetten S, Meyer O, Godolias G. Application of bar disk prolapse. Tcrm. 2017;13:87–94. holmium:YAG laser in epiduroscopy: extended practic- [9] Al-Khawaja DO, Mahasneh T, Li JC, et al. Surgical abilities in the treatment of chronic back pain syn- treatment of far lateral lumbar disc herniation: a safe drome. J Clin Laser Med Surg. 2002;20:203–206. and simple approach. J Spine Surg. 2016;2:21–24. [18] Bridwell KH, Lenke LG, McEnery KW, et al. Anterior [10] Yue JJ, Scott DL, Han X, et al. The surgical treatment fresh frozen structural allografts in the thoracic and of single level multi-focal subarticular and paracentral lumbar spine. Do they work if combined with poster- and/or far-lateral lumbar disc herniations: the single ior fusion and instrumentation in adult patients with incision full endoscopic approach. Int J Spine Surg. kyphosis or anterior column defects? Spine 1995;20: 2014;8:16. 1410–1418. [11] Phan K, Dunn AE, Rao PJ, et al. Far lateral microdis- [19] Wang L, Wang Y, Li Z, et al. Unilateral versus bilateral cectomy: a minimally-invasive surgical technique for pedicle screw fixation of minimally invasive transfora- the treatment of far lateral lumbar disc herniation. J minal lumbar interbody fusion (MIS-TLIF): a meta-ana- Spine Surg. 2016;2:59–63. lysis of randomized controlled trials. BMC Surg. 2014; [12] O’Toole JE, Eichholz KM, Fessler RG. Minimally inva- 14:87. sive far lateral microendoscopic discectomy for extra- [20] Best NM, Sasso RC. Efficacy of translaminar facet foraminal disc herniation at the lumbosacral junction: screw fixation in circumferential interbody fusions as cadaveric dissection and technical case report. Spine compared to pedicle screw fixation. J Spinal Disord J. 2007;7:414–421. Tech. 2006;19:98–103. [13] Ruetten S, Komp M, Godolias G. An extreme lateral [21] Ikuta K, Tono O, Senba H, et al. Translaminar microen- access for the surgery of lumbar disc herniations doscopic herniotomy for cranially migrated lumbar inside the spinal canal using the full-endoscopic uni- disc herniations encroaching on the exiting nerve portal transforaminal approach–technique and pro- spective results of 463 patients. Spine 2005;30: root in the preforaminal and foraminal zones. Asian 2570–2578. Spine J. 2013;7:190–195. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Computer Assisted Surgery Taylor & Francis

Minimally invasive surgical techniques for the therapy of far lateral disc herniation in middle-aged and elderly patients

Computer Assisted Surgery , Volume 24 (sup1): 7 – Oct 1, 2019

Loading next page...
 
/lp/taylor-francis/minimally-invasive-surgical-techniques-for-the-therapy-of-far-lateral-7tHppJE903

References

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
Taylor & Francis
Copyright
© 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.
ISSN
2469-9322
DOI
10.1080/24699322.2018.1557897
Publisher site
See Article on Publisher Site

Abstract

COMPUTER ASSISTED SURGERY 2019, VOL. 24, NO. S1, 13–19 https://doi.org/10.1080/24699322.2018.1557897 RESEARCH ARTICLE Minimally invasive surgical techniques for the therapy of far lateral disc herniation in middle-aged and elderly patients Weijian Ren, Yu Chen and Liangbi Xiang Liaoning University of Traditional Chinese Medicine, Shenyang, People’s Republic of China KEYWORDS ABSTRACT Far lateral disc herniation, To examine the clinical results of different minimally invasive techniques for the therapy of far instability, minimally lateral disc herniation in middle-aged and elderly patients. An endoscopic approach (percutan- invasive, radicuar pain eous endoscopic lumbar discectomy; PELD), MIS-TLIF combined with contralateral translaminar screw (MIS-TLIF CTS), and MIS-TLIF combined with bilateral pedicle screws (MIS-TLIF BPS) were evaluated via a retrospective chart review. Data from 74 consecutive middle-aged and elderly patients with far lateral disc herniation were analyzed. All patients underwent surgery; 19 with PELD, 24 with MIS-TLIF CTS, and 31 with MIS-TLIF BPS. Clinical data included the length of the incision, duration of the operation, estimated blood loss, hospitalization time, operation cost, recurrence rate, and fusion rate. Preoperative and postoperative patient outcomes including the VAS, ODI scores and MacNab criteria were assessed and recorded. The mean follow-up time was 26.4 months (range from 14 to 46 months). Compared with the internal fixation groups, the length of the incision, duration of operation, estimated blood loss, and hospitalization time were obviously lower in the PELD group. The difference in operation cost among the three methods was statistically significant. The postoperative VAS scores for LBP and LP decreased sig- nificantly as compared with those recorded preoperatively. The postoperative ODI scores were lower than those recorded preoperatively. MacNab criteria rating excellent, good and fair results were in 27, 37 and 10 patients, respectively. Conclusion: PELD, MIS-TLIF CTS, and MIS-TLIF BPS are all effective minimally invasive techniques for the therapy of single segment far lateral lum- bar disc herniation in middle-aged and elderly patients. PELD had a shorter operation time and less surgical trauma, being a less invasive and more economical method; however, there was no recurrence of disc herniation after fixation. Compared with MIS-TLIF BPS, MIS-TLIF CTS obtained a similar clinical effect and certain costs were saved. Introduction tissue, lamina, but also directly expose the far lateral protruding disc [5, 6]. As a result of its minimal surgical With the development of society and improvements in trauma, paraspinal lateral surgeries such as PELD, MIS- medical technology, the aging population is becoming TLIF CTS, and MIS-TLIF BPS have been widely used in increasingly apparent [1]. The facet joints and interver- recent years [7, 8]; however, the surgical comparison of tebral discs play an important role in maintaining exer- these three approaches in middle-aged and elderly cise in old age. Lumbar and lower extremity pain in patients with far lateral disc herniation is still lacking. middle-aged and elderly patients has been shown to The purpose of this study is to examine the necessity mainly originate from lumbar disc herniation [2]. The of internal fixation and compare the clinical results of far lateral lumbar disc herniation (FLDH) accounts for different minimally invasive approaches for treatment 0.7–11% of all disc herniation [3].The prolapsed disc of FLDH in middle-aged and elderly patients. often compresses the exiting root and ganglion, lead- ing to severe radicular pain. The traditional posterior midline approach, paraspinal and endoscopic Materials and methods approaches are common surgical approaches for FLDH [4]. Typically, the minimally invasive paraspinal Data were collected from consecutive patients treated approaches not only minimize the damage to soft by surgery at the General Hospital of Shenyang CONTACT Weijian Ren renweijian2009@163.com Liaoning University of Traditional Chinese Medicine, Number 79 Chongshan Eastern Road, Huanggu District, Shenyang, Liaoning, 110847, People’s Republic of China. 2019 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. 14 W. REN ET AL. Military Region between March 2010 and December The MIS-TLIF CTS group 2016. The enrolled criteria were illustrated below: Patients received general anesthesia in the prone pos- patients who (1) had one segment far lateral disc her- ition, and the localization of target segment was niation, lower extremity symptoms, and lower back guided by preoperative C-arm which parallel to the pain; (2) demonstrted not relieving or aggravating upper end plate. A 30-mm vertical skin incision was after 3 months of conservative treatment; (3) pre- performed approximately 1–2 cm lateral to the midline sented with symptoms that were consistent with sin- of the spine, followed by transmuscular dilatation gle segment lumbar disc herniation on MRI and/or CT. between the polyfissure and longissimus muscles. The The criteria of exclusion were illustrated below: working channel was inclined approximately 5–10 patients who (1) had multi-segment lumbar interverte- toward the disc space to localize the disc prolapse bral disc herniation; (2) had undergone spinal surgery; (21). The surgical methods were as follows: decom- or (3) had a history of fractures, tumors, infections, or pression, excision of the articular process and part of other spinal diseases. These patients corresponded to the yellow ligament; exposure of the exiting nerve 4.6% of those who experienced lumbar disc surgery at root; opening the exiting nerve root canal; discectomy; that time. Forty-one patients were men and 33 were end plate treatment; and intervertebral bone graft and women, aged between 57 and 82 years old (mean cage implantation. The ipsilateral pedicle screws were 63.3). There were 26 cases in L5/S1 level, 32 in L4/5 positioned directly. For the purpose to keep the bal- level, 15 in L3/4 level, and 1 in L2/3 level. ance of spine, the translaminar screw was placed Comorbidities included coronary heart disease, dia- along the base of the superior spinous process and betes, and tobacco use(Table 1). Clinical data included contralateral lamina to opposite facet joint(Figure 2). the length of the incision, duration of operation, esti- mated blood loss, hospitalization time, operation cost, The MIS-TLIF BPS group recurrence rate, and fusion rate. Outcomes included Patients underwent the similar surgical procedures, the VAS score for LBP and LP and the ODI score pre- and the contralateral percutaneous pedicle screws operatively and at 1-week and 12-months postopera- were inserted under the guidance of a C tively, which were defined as excellent, good, fair or arm(Figure 3). poor based on the MacNab criteria. The study was approved by the Ethics Committee of the General Statistical analysis Hospital of Shenyang Military Region. SPSS 19.0 was used for statistical analysis. The com- parison was demonstrated as follows: homogeneity of Surgical techniques variance and normal distribution using an independ- ent sample t-test, and variance of arrhythmia and nor- The PELD group mal distribution using a t-test. Attribute data were The PELD was performed under local anesthesia in the analyzed with v test. A p value< .05 was considered prone position. Firstly, location of body surface inci- statistically significant. sion was guided by C-arm, and a 0.7-mm guiding wire was inserted via the anaesthetic puncture needle. A Results double-channel eccentric guide rod with an outer diameter of 6 mm was placed toward the prolapse, The mean follow-up time was 26.4 months (range and the dilator was inserted into the extraforaminal from 14 to 46 months). The three groups had equiva- lumbar disc herniation. An inner diameter of 6.5 mm lent average age, gender distribution, level distribu- surgical working tube with a beveled opening was tion, and comorbidities. Compared with the internal then pushed ventrally over the dilatator to protect the fixation groups, the length of the incision, duration of nerve roots. The beveled opening of the tube was operation, estimated blood loss, and hospitalization adjusted and pushed toward the prolapse. Secondly, time were obviously lower (p< .05) in the PELD group. nerve root decompression was performed under grav- The difference in operation cost was statistically sig- ity-controlled liquid flow and visual control. In add- nificant; PELD was the least, followed by MIS-TLIF CTS, ition, a high frequency semi-active flexible bipolar and then MIS-TLIF BPS(Table 2). The postoperative VAS probes were used for coagulation hemostasis and soft scores for LBP and LP decreased significantly as com- tissue formation(Figure 1). pared with those recorded preoperatively. The COMPUTER ASSISTED SURGERY 15 postoperative ODI scores were lower than those necessity of internal fixations. For elderly patients with recorded preoperatively (p< .05), with the postopera- severe osteoporosis or other diseases, who could not tive LBP in the PELD group being significantly lower tolerate general anesthesia, we used PELD to remove than others. In addition, there was no significant dif- the prolapse under local anesthesia. Those compli- cated with degenerative instability, spondylolisthesis, ference in the ODI or VAS scores according to MacNab criteria among the three groups postoperatively isthmus, or giant disc calcification, we performed MIS- (p> .05). MacNab criteria rating excellent, good and TLIF CTS or MIS-TLIF BPS. fair results were in 27, 37 and 10 patients, In the present study, the length of the incision, dur- ation of the operation, estimated blood loss, and hos- respectively(Table 3). The PELD group had two cases of postoperative pitalization time in the PELD group were apparently lower than other groups, reflecting that PELD for recurrence, and the other two groups had no recur- rence; however, there was no significant difference patients with FLDH has a lot of advantages. Recent (p> .05). There was also no significant difference in studies have also documented good results by PELD the fusion rate at 1-year follow-up between the two for FLDH [16]. Lower blood loss and a shorter oper- ation time appear to be the benefits of a PELD surgi- groups with internal fixations. Incision infection occurred in 2 cases in all three groups, but no other cal approach, resulting in little soft tissue damage due complications occurred. to the gravity-controlled liquid flow and the applica- tion of high frequency semi-active flexible bipolar probes. Guiding by lens optics under controlled liquid Discussion not only enables clear visual environment but also Far lateral disc herniation (FLDH) is also known as for- reduces hemorrhage. The bipolar probes can be aminal, intraforaminal, or extreme lateral disc hernia- applied in the immediate vicinity of neural structures tion, which is defined as a disc herniation or prolapse and avoid intraoperative bleeding [17]. Patients with that resides lateral and beneath to the upper and FLDH who undergo PELD can recover faster and walk lower pedicles and compresses the exiting root and down early. The reasons are as follows: (1) faster ganglion [10, 11]. FLDH rarely causes compression of recovery of lower waist soft tissue after PELD with lit- the dural sac, cauda equina and dysfunction of the tle tissue resection and almost no injury to the bony bowel and bladder. In the current research, the aver- structure helps to strengthen the waist and enable age patient age was 63.3 years old (range from 57 to earlier occupational and athletic levels of activity; (2) 82), which is consistent with that in previous studies less trauma reduces the theoretical probability of poor [11] and shows that FLDH predominately occurs in wound healing and fat liquefaction as compared with middle-aged and elderly patients. Although conserva- traditional surgery; and (3) rehabilitative measures are tive treatment can occasionally be effective, surgery is not necessary. Kambin et al. reported that a few usually required [12]. Various surgical approaches have patients presented with postoperative hip or leg caus- been performed for the operative treatment of FLDH. algia secondary to immature operation of the dorsal With the improvement and popularity of minimally root ganglion; however, no patients experienced caus- invasive spine technology, PELD, MIS-TLIF CTS, and algia in the present study and the clinical effect was MIS-TLIF BPS have become widely used as ameliora- satisfactory. As for the reasons; exact preoperative tive treatments [13]. Compared with traditional mid- measurement is necessary and the manipulation of line approaches, these three minimally invasive PELD has a prolonged learning curve. Firstly, in most techniques are implemented with a mini-incision, patients presented with FLDH, the outreaching angle require smaller muscle soft tissue dissection, supraspi- and the distance between the incision and the midline nal interspinous ligaments and spinous process are needs to be measured. The purpose was to make pos- retained. One previous study reported that PELD has sible tangential reaching of the sagittal and coronal shown comparable results to the standard surgery localization of the prolapse. Secondly, the recognition [14]; however, another study reported that PELD in of the shape and orientation of the disc, ligaments, elderly patients had a higher reoperation rate during nerve, and vessels plays a vital role in the endoscopic the first 3.4 years of follow-up than traditional discec- environment; and continuing improvement of endo- tomy [15]. Due to this discrepancy, the present study scopic instruments enables a wider and more efficient compared the clinical results of PELD, MIS-TLIF CTS, decompression than ever. Thirdly, the degree of intra- and MIS-TLIF BPS for the treatment of FLDH in mid- operative decompression mainly depends on the dle-aged and elderly patients and examined the range of the fluid-controlled nerve root motion and 16 W. REN ET AL. Table 1. Patient baseline characteristics. A(N¼ 19) B(N¼ 24) C(N ¼ 31) P Age, y 64.7 ± 7.3 64.1 ± 6.3 63.9 ± 6.4 0.974 55–59 60–69 70 55–59 60–69 70 55–59 60–69 70 6 9 4 8 10 6 10 14 7 0.997 Gender n (%) Male 10 14 17 0.929 Female 9 10 14 Level n (%) 0.681 L2/3 1 0 0 L3/4 4 4 7 L4/5 9 11 12 L5/S1 5 9 12 Comorbidity type (%) 0.992 Diabetes 4 5 7 Coronary artery disease 6 7 8 Tobacco use 6 6 7 Table 2. Surgical outcomes. A(N ¼ 19) B(N¼ 24) C(N¼ 31) P(AB) P(AC) P(BC) length of incision, mm 7.7 ± 1.1 33.2 ± 2.6 34.1 ± 2.0 <0.05 <0.001 0.172 Duration of operation, min 97.1 ± 9.6 163.9 ± 9.5 167.2 ± 8.2 <0.001 <0.001 0.175 Estimated blood loss, mL 14.2 ± 6.9 141.3 ± 18.7 147.4 ± 19.7 <0.001 <0.001 0.244 hospitalization time, d 5.2 ± 0.9 10.8 ± 1.3 11.2 ± 1.2 <0.001 <0.001 0.237 operation cost, CNY 23001.1 ± 2426.2 51164.3 ± 5228.7 65805.6 ± 2886.3 <0.001 <0.001 <0.001 recurrence rate 11% 0 0 fusion rate – 100% 100% Table 3. Pre- and postoperative LP VAS score, ODI score and Macnab criteria assessment. A B C P(AB) P(AC) P(BC) VAS(BP) Preoperative 4.7 ± 1.1 4.9 ± 1.1 5.0 ± 1.0 0.692 0.355 0.594 1w postoperative 1.3 ± 0.5 2.8 ± 1.1 3.1 ± 1.0 <0.001 <0.001 0.333 1y postoperative 0.7 ± 0.5 1.2 ± 0.5 1.4 ± 0.7 <0.05 <0.001 0.227 VAS(LP) Preoperative 7.7 ± 0.9 7.8 ± 0.7 7.5 ± 0.9 0.663 0.508 0.209 1w postoperative 2.5 ± 0.5 2.5 ± 0.5 2.6 ± 0.6 0.868 0.382 0.444 1y postoperative 1.4 ± 0.8 1.5 ± 0.6 1.5 ± 0.6 0.858 0.754 0.878 ODI Preoperative 76.8 ± 6.7 74.3 ± 6.5 76.0 ± 6.9 0.218 0.671 0.364 1w postoperative 27.9 ± 2.7 26.5 ± 3.5 26.4 ± 3.6 0.131 0.109 0.941 1y postoperative 23.6 ± 3.2 22.9 ± 3.6 22.8 ± 3.6 0.508 0.442 0.944 Macnab criteria assessment .986 Excellent 7 9 11 Good 10 12 15 Fair 2 3 5 Poor 0 0 0 the patients’ expression of leg pain relief. As a result, scores at 1-week and 12-months post-surgery. adequate exposure and decompression could be Postoperative LBP in the PELD was significantly lower obtained and causalgia was avoided. than the others. The difference in cost among the three groups was In terms of neurofunctional recovery, the postop- statistically significant. The main reason for the lower erative ODI scores were significantly lower than cost of PELD is that the surgery is performed under those recorded preoperatively, indicating that min- local anesthesia and does not implant internal fixa- imally invasive surgeries can restore nerve function tions. The appraisal of the spend of internal fixtures and provide relief from the radiating pain. In the demonstrated that the application of MIS-TLIF CTS for present study, endoscopic decompression, nucleus one level fusion increased the spend by nearly 20% as pulposus excision, and decompression of the exiting compared with PELD. In terms of cost savings, a nerve root canal in the PELD group were similar to shorter hospitalization time also played a key role. the procedures in the MIS-TLIF CTS and MIS-TLIF The present data show that the postoperative VAS BPS groups. scores for LBP and LP decreased significantly com- Moreover, there were no statistically differences in pared with those recorded preoperatively; and all MacNab criteria and postoperative ODI scores among three minimally invasive operations had reduced VAS the three groups, demonstrating that the function of COMPUTER ASSISTED SURGERY 17 Figure 1. a typical case of PELD. Notes: (A) coronal CT shows L5/S1 right FLDH. (B) sagittal MRI shows L5/S1 FLDH. (C) and (D) intraoperative channel X-ray images. (E) and(F)Exposure of exiting nerve root. Figure 2. A typical case of MIS-TLIF CTS. Notes: (A) CT shows L4/5 left FLDH. (B) sagittal MRI shows L4/5 FLDH. (C) and (D) X-ray images demonstrate permanent position after 1 year.(E) and (F) coronal CT images after 1 year. these approaches in the therapy of middle-aged and that postoperatively scoliosis occurs more frequently elderly patients with FLDH is relatively comparable. in unilateral than bilateral groups [19]; however, the The main goal of the implant is to fix the spine and scoliotic patients did not have obvious clinical symp- ensure bone graft fusion; thus, the fusion rate is the toms in recent researches. To avoid the occurrence of most important index to evaluate. Bridwell et al., intro- scoliotic deformities, the patients with FLDH were duced the four grading criteria of radiographic fusion treated with MIS-TLIF CTS or MIS-TLIF BPS. Although [18]; both grades I and II are considered radiographic there exists a difference in the operation cost, the dif- signs of solid fusion. Previous studies have showed ference of fusion rate was not significantly different 18 W. REN ET AL. Figure 3. A typical case of MIS-TLIF BPS. Notes: (A) coronal CT shows L5/S1 right FLDH. (B) sagittal MRI shows L5/S1 FLDH. (C) and (D) X-ray images demonstrate permanent position after 1 year.(E)coronal and(F)sagittal CT images after 1 year. between the two groups at 1-year follow-up. Best NM invasive and more economical method; however, there et al., also reported that there were no apparent dif- was no recurrence of disc herniation after fixation. ferences in range of motion, fixation stiffness, or Compared with MIS-TLIF BPS, MIS-TLIF CTS obtained a multi-directional activities between the combination of similar clinical effect and certain costs were saved. unilateral pedicle screws and the translaminar screw and bilateral pedicle screw fixation [20]. Funding The PELD group had two cases of postoperative This work was supported by the Foundation of the Liaoning recurrence, which were revised by MIS-TLIF CTS; never- Province Doctor Startup Fund [201601389], the State Key theless, the difference in the recurrence rate was not Laboratory of Robotics [2017-O01], the Open Project statistically significant. However, there was no recur- Program of the State Key Lab of CAD&CG [A1718], the Open rence of disc herniation after internal fixations. There Project Program of the State Key Laboratory of Trauma, Burn were two cases of incision infection in all three groups, and Combined Injury [SKLKF201705] and the State Key which were cured by conservative treatment. Laboratory of Materials Processing and Die & Mould Technology [P2018-011]. There were many limitations in the current study. Firstly, this is a retrospective study with a small sample size; an additional multicenter and prospective study References with a larger sample is needed. Secondly, patient [1] The World Population Prospects. 2015 Revision.at selection has some limitations; multifocal lumbar disc <http://esa.un.org/unpd/wpp/Publications/Files/Key_ herniation needs further research. Thirdly, the included Findings_WPP_2015.pdf> studies were short- or medium-term. Long-term [2] Goldring MB, Goldring SR. Osteoarthritis. J Cell follow-up periods of the three methods should be Physiol. 2007;213:626–634. evaluated in the future. [3] Kim DG, Eun JP, Park JS. New diagnostic tool for far lateral lumbar disc herniation: The clinical usefulness of 3-Tesla magnetic resonance myelography compar- Conclusion ing with the discography CT. J Korean Neurosurg Soc. 2012;52:103–106. PELD, MIS-TLIF CTS, and MIS-TLIF BPS were all effective [4] Blamoutier A. Surgical discectomy for lumbar disc minimally invasive methods for the therapy of single herniation: surgical techniques. Orthop Traumatol segment far lateral lumbar disc herniation in middle- Surg Res. 2013;99:S187–S196. aged and elderly patients. PELD had a shorter [5] Quaglietta P, Cassitto D, Corriero AS, et al. Paraspinal operation time and less surgical trauma, being a less approach to the far lateral disc herniations: COMPUTER ASSISTED SURGERY 19 retrospective study on 42 cases. Acta Neurochir. 2005; [14] Kim CH, Chung CK, Park CS, et al. Reoperation rate 92:115–119. after surgery for lumbar herniated intervertebral disc [6] Lee JS, Woo JY, Jang JS, et al. Combined interlaminar disease: nationwide cohort study. Spine 2013;38: and paraisthmic approach for co-existing intracanal 581–590. and foraminal lesion. Korean J Spine. 2015;12: [15] Kim CH, Chung C, Choi KY, et al. The selection of 256–260. open or percutaneous endoscopic lumbar discectomy [7] Sethi A, Lee S, Vaidya R. Transforaminal lumbar inter- according to an age cut-off point: national-wide body fusion using unilateral pedicle screws and a cohort study. Spine 2015;40:E1063–E1070. translaminar screw. Eur Spine J. 2009;18:430–434. [16] Jang JS, An SH, Lee SH. Transforaminal percutaneous [8] Wang Y-P, An J-L, Sun Y-P, et al. Comparison of out- endoscopic discectomy in the treatment of foraminal comes between minimally invasive transforaminal and extraforaminal lumbar disc herniations. J Spinal lumbar interbody fusion and traditional posterior lum- Disord Tech. 2006;19:338–343. bar intervertebral fusion in obese patients with lum- [17] Ruetten S, Meyer O, Godolias G. Application of bar disk prolapse. Tcrm. 2017;13:87–94. holmium:YAG laser in epiduroscopy: extended practic- [9] Al-Khawaja DO, Mahasneh T, Li JC, et al. Surgical abilities in the treatment of chronic back pain syn- treatment of far lateral lumbar disc herniation: a safe drome. J Clin Laser Med Surg. 2002;20:203–206. and simple approach. J Spine Surg. 2016;2:21–24. [18] Bridwell KH, Lenke LG, McEnery KW, et al. Anterior [10] Yue JJ, Scott DL, Han X, et al. The surgical treatment fresh frozen structural allografts in the thoracic and of single level multi-focal subarticular and paracentral lumbar spine. Do they work if combined with poster- and/or far-lateral lumbar disc herniations: the single ior fusion and instrumentation in adult patients with incision full endoscopic approach. Int J Spine Surg. kyphosis or anterior column defects? Spine 1995;20: 2014;8:16. 1410–1418. [11] Phan K, Dunn AE, Rao PJ, et al. Far lateral microdis- [19] Wang L, Wang Y, Li Z, et al. Unilateral versus bilateral cectomy: a minimally-invasive surgical technique for pedicle screw fixation of minimally invasive transfora- the treatment of far lateral lumbar disc herniation. J minal lumbar interbody fusion (MIS-TLIF): a meta-ana- Spine Surg. 2016;2:59–63. lysis of randomized controlled trials. BMC Surg. 2014; [12] O’Toole JE, Eichholz KM, Fessler RG. Minimally inva- 14:87. sive far lateral microendoscopic discectomy for extra- [20] Best NM, Sasso RC. Efficacy of translaminar facet foraminal disc herniation at the lumbosacral junction: screw fixation in circumferential interbody fusions as cadaveric dissection and technical case report. Spine compared to pedicle screw fixation. J Spinal Disord J. 2007;7:414–421. Tech. 2006;19:98–103. [13] Ruetten S, Komp M, Godolias G. An extreme lateral [21] Ikuta K, Tono O, Senba H, et al. Translaminar microen- access for the surgery of lumbar disc herniations doscopic herniotomy for cranially migrated lumbar inside the spinal canal using the full-endoscopic uni- disc herniations encroaching on the exiting nerve portal transforaminal approach–technique and pro- spective results of 463 patients. Spine 2005;30: root in the preforaminal and foraminal zones. Asian 2570–2578. Spine J. 2013;7:190–195.

Journal

Computer Assisted SurgeryTaylor & Francis

Published: Oct 1, 2019

Keywords: Far lateral disc herniation; instability; minimally invasive; radicuar pain

References