- Email: [email protected]
Brake reaction time before and after surgery for patients with sequestrectomy versus conventional microdiscectomy
Journal of Clinical Neuroscience 72 (2020) 214–218
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical study
Brake reaction time before and after surgery for patients with sequestrectomy versus conventional microdiscectomy Martin Thaler a,⇑, David Putzer b,1, Richard Lindtner c, Dietmar Krappinger c, Christian Haid a, Alois Obwegeser d, Ricarda Lechner a a
Department of Orthopaedic Surgery, Medical University Innsbruck, Innsbruck, Austria Department of Orthopaedic Surgery, Experimental Orthopaedics, Medical University Innsbruck, Innsbruck, Austria Department of Trauma Surgery, Medical University Innsbruck, Innsbruck, Austria d Tiroler Landeskliniken, Innsbruck, Austria b c
a r t i c l e
i n f o
Article history: Received 14 August 2019 Accepted 30 November 2019
Keywords: Brake reaction time Sequestrectomy Lumbar disc surgery Disectomy Impairment of reaction time
a b s t r a c t The aim of this study was to compare the effects of sequestrectomy versus conventional microdiscectomy on breaking response time (BRT) for lumbar disc herniation (LDH). BRT is the key factor for return to drive recommendations after surgery. A prospective clinical study was conducted. Patients aged 25–65 years who underwent surgery for lumbar disc herniation and held a valid motorcar driving license were recruited in a single institution. The patients were assessed before surgery, immediately after the surgery and at the follow up examination 30 days post-surgery. BRT was measured using a driving simulator, a visual analogue scale (VAS) was used for pain assessment. BRT values were compared with BRT values of a healthy control group. In patients treated with microdiscectomy BRT reduced from 749 (±223) msec before surgery to 649 (±223) msec immediately after the surgery. In the sequestrectomy group BRT reduced from 852 (±561) msec before surgery to 693 (±173) msec immediately after the surgery. BRT at follow up was 610 (±145) msec for patients treated with microdiscectomy and 630 (±98) msec for patients operated with sequestrectomy. BRT for healthy controls was 487 (±116) msec. Pain improved significantly for both patient samples. Sequestrectomy and microdiscectomy were associated with similar effects on pain and BRT after surgery. There was no statistically significant difference between BRT of both patient samples at 30 days follow up examination. Both surgical techniques showed a positive effect on BRT. No statistically significant difference between sequestrectomy and microdiscectomy on BRT could be found. Ó 2019 Elsevier Ltd. All rights reserved.
1. Introduction Previous published studies indicated that 60–80% of humans would suffer from back pain during their lifetime [1], and 2%-10% of them need surgical treatment for sciatica [2]. Surgery for lumbar disc herniation (LDH) is the most common surgical procedure performed for radiculopathy [3]. Most patients with back pain and radiating pain undergo standard microdiscectomy with the removal of the free disc fragments followed by aggressive or conservative excision of the intervertebral disc [4]. Another encouraging surgical method is sequestrectomy, with the removal of only
⇑ Corresponding author at: Medical University Innsbruck, Department of Orthopaedic Surgery, Anichstr. 35, A-6020 Innsbruck, Austria. E-mail address: [email protected] (M. Thaler). 1 ORCID: 0000-0001-9439-0051. https://doi.org/10.1016/j.jocn.2019.11.041 0967-5868/Ó 2019 Elsevier Ltd. All rights reserved.
extruded disc fragments and any loose pieces in the disc space without clearing the intervertebral disc. There are several publications comparing microdiscectomy and sequestrectomy [3-9]. Most of these reports revealed comparable results regarding reherniation rates, pain after surgery, functional outcome and complication rates [3,7-9]. Some studies postulated that sequestrectomy is associated with a slightly better clinical outcome regarding radicular pain at the short term follow up [7] and less postoperative analgesic consumption [7,10,11], the rate of reherniation was reported to be slightly higher in microdiscectomy patients. However, a potential disadvantage of sequestrectomy versus conventional microdiscectomy is a higher risk of recurrent disc herniation and potential advantages are more preserved architecture of the spine and less back pain (LBP) after surgery [7,10,11] Patients commonly inquire about resuming everyday social activities like return to work or driving after surgery. The ability
M. Thaler et al. / Journal of Clinical Neuroscience 72 (2020) 214–218
to return to drive a car after surgery is an important issue in terms of quality of life and maintain social life activities. Breaking response time (BRT) is the most important factor responsible for driving safety [12,13]. BRT has already been studied in patients with lumbar disc surgery [14,15] demonstrating a significant reduction of BRT after the surgery and a positive impact on driving safety after surgery. The authors based their recommendations regarding return to driving on the patient’s preoperative data and recommended to return to drive after discharge from hospital. However, no data was found comparing sequestrectomy and microdiscectomy on patients driving ability were found. Therefore, the objective of the current study was to compare BRT after sequestrectomy and microdiscectomy. We also investigated BRT in both patient samples on longitudinal comparison regarding preoperative (PreOP), immediately postoperative and 4 weeks postoperative (PostOP) BRT values and compared BRT of both patient samples with the BRT of healthy controls.
215
light until the participant pressed the brake pedal was recorded in milliseconds (msec). Each patient performed three dry runs. Then BRT was measured ten times. Pain was measured for all patients with a Visual Analogue Scale (VAS), ranging from 0 for no pain to 10 for severe pain on each test occasion. Driving frequency (never, once a month, once a week, and daily) and intake of analgesics was recorded on each test occasion. Data were processed using the Graph Pad Prism (Prism 7, Graph Pad Software Inc., San Diego, CA, USA). Driving reaction time were not normally distributed. The Kruskal Wallis test was used to test for longitudinal differences in BRT. P-values <0.05 were defined as statistically significant. If significance was seen Dunn’s tests were performed for post hoc analysis (pre-/post-op comparison, postop/FU comparison). P-values <0.05 were defined as statistically significant. Mann–Whitney U Test (alpha level of 0.05) was used for comparison between single time points of both groups.
2. Materials and methods 3. Results This study was approved by the university´s ethics committee and all procedures followed were in accordance with the ethical standards of the Helsinki Declaration of 1975, as revised in 2000. Written informed consent was obtained from each study patient. Sixty consecutive patients scheduled to surgery for a single-level lumbar disc herniation were included in the present study. In a randomized setup 30 patients were treated with microdiscectomy and then 30 patients were treated with sequestrectomy. All included patients had a valid driving license. Patients suffering from other diseases like central neurological disorders, acute trauma, cauda equina syndrome, pathologic or infectious diseases of the spine, stenosis of the spinal canal, spondylolisthesis, scoliosis or kyphosis, presence of concomitant spinal disease and previous spinal surgery were excluded from the study. All patients failed to improve with non-surgical therapy and presented with pain due to lumbar disc herniation lasting >6–8 weeks. In all patients magnetic resonance imaging (MRI) confirmed disc herniation. Patients with free disc fragments, subligamentary herniations and transannular herniations (herniation in continuity with the disc space) were included. The patients received either a standard microdiscectomy with removal of herniated disc material plus disc tissue from the intervertebral space or a sequestrectomy with removal of the herniated disc material only. Total intravenous anaesthesia was used in all patients. In microdiscectomy the disc space was entered with a rongeur to remove as much of the nucleus, i.e., the loose intradiscal tissue, as possible. No curettes or similar instruments were used intradiscally to avoid injury to the cartilaginous endplates or the annulus. In the sequestrectomy-treated group, only the herniated disc material was removed and the intervertebral disc space was not entered by any instrument. Thus, the central nucleectomy was the actual difference between the two surgical procedures. The control group consisted of 31 healthy subjects (19 females, 12 males; mean age 52 years; SD 7.7 years) with a valid driving license, at least 10 years of driving experience and no history of spinal pathology [16]. All 4 surgeries were performed by 4 experienced neurosurgeons For the BRT measurements a driving simulator as described previously was used [14,15,17]. When the accelerator was fully pressed by the participant, a green signal light lit up, indicating that the participant was driving in a ready to brake fashion. Randomly, after 5–10 s a red signal light and simultaneously the electronic clock were activated. The patients were advised to brake with their right foot as quick as possible when a red signal light appeared. The time interval from the appearance of the red signal
The first examination (preoperative: pre-op) was performed 1 day (median, range 1–6 days) before surgery, the second examination before hospital discharge (3 days (median, range 2–7 days)) and the third test at follow-up (FU: 31 days (median, range 20–58)) examination. Two patients in the microdisectomy group underwent a second stage procedure, because the initial decompression was not sufficient layer discectomy (Table 1). One patient showed a cerebrospinal fluid (CSF) leakage after the surgery, one showed an insufficient initial decompression and had to be revised. In the sequestrectomy group one patients had a CSF after surgery and had to be revised. Demographic and baseline characteristics of the patients are shown in Table 1. When comparing the microdisectomy group with the sequestrectomy group no difference (p > 0.05 U-Test) could be found between patients operated with the seqestrectomy and the microdiscectomy technique assessing VAS for back pain and VAS for leg pain as well preoperatively, postoperatively and at FU (Table 2 vertical comparisons). A significant difference could (p < 0.01 KS-Test) be found when analyzing the differences between each time step (pre-op, post-op and FU) for the microdisectomy group and the seqeustrectomy group for both scores assessed (Table 2 horizontal comparisons). There was no significant difference between pre and postoperative VAS regarding pack pain in both groups (p > 0.5 Dunn’s Test). After 6 weeks a significant lower VAS back (p = 0.0189 Dunn’s Test) was recorded for patients who underwent microdisectomy surgery (Table 2). Patients of both groups showed a significant lower VAS leg after surgery (p = 0.0001 Dunn’s Test) compared to preoperative assessed VAS leg (Table 2). Comparing BRT after ctomy to a control group (487 SD(116) N = 31) of healthy subjects statistical significant higher values was found preoperatively (p < 0.0001 Tukey’s Test both groups) and postopereatively (p = 0.0023 sequestrectomy group and p = 0.0025 microdisectomy group, Tukey’s Test) for the patients with disc herniation (Fig. 1). No difference could be found between patients operated with the seqestrectomy and the microdiscectomy technique preoperatively (p = 0.2155, Tukey’s Test), postoperatively (p = 0.9997, Tukey’s Test) and at FU (p = 0.9404 Tukey’s Test). At a FU period of 30 days no difference could be found between patients operated with sequestrectomy and the control group (p = 0.1136, Tukey’s Test) and patients operated with microdiscectomy and the control group (p = 0.0523, Tukey’s Test) (Fig. 1).
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Table 1 Comparison of demographic data of patients operated with microdiscectomy and sequestrectomy. Data is presented as mean (SD). Microdiscectomy
Sequestrectomy
Controls
45 (10) 16 14
51 (13) 10 20
52 (8) 19 12
L2/L3 L3/L4 L4/L5 L5/S1
0 4 14 14
1 3 16 10
CSF
1
1
Age (mean (sd)) [y] Female [n] Male [n] Herniation level
Complications
Table 2 Longitudinal and cross-sectional comparison of VAS in patients with microdiscectomy and sequestrectomy (pre-op: preoperative; post-op: postoperative; FU: follow-up). Data in frames: p values of longitudinal (a = 0.05) and cross-sectional (a = 0.05) comparison. Data in frames: brake response time as mean (SD).
VAS back Microdisectomy Mann-Whitney U Sequestrectomy VAS leg Microdisectomy Mann-Whitney U Sequestrectomy
pre-op
Dunn’s
3.4 (2.7) " 0.7584 ; 3.2 (2.7)
0.5100
?
0.5390
?
0.0001
?
<0.0001
?
4.2 (2.7) " 0.4364 ; 4.7 (2.5)
Fig. 1. Mean and standard deviation (bars) of BRT in msec of sequestrectomy and mircodisectomy group in comparison to the control group. ****Indicates a p < 0.0001, *** indicates p > 0.0002, ** indicates p > 0.002, * indicates p > 0.03.
Comparing BRT in the longitudinal follow ups a statistically significant difference was seen for patients operated with sequestrectomy and microdiscectomy (p > 0.05, Table 3, ANOVA with Tukey’s multiple comparisons test). Post-hoc analysis was set to the alpha level of 0.05 and revealed no significant difference between BRT pre-op and BRT post-op and between BRT post-op and BRT at follow up time for patients which underwent sequestrectomy or microdicectomy after disc herniation (Table 3) A significant difference was found between pre-op BRT and follow up period for both groups (p = 0.0375 for sequestrectomy and p = 0.0264 for disectomy). No correlation was found between VAS for back or leg pain and BRT at all subsequent time points of measurement. No correlation between pain medication and BRT was found. 4. Discussion Several articles provide a comparison between sequestrectomy and microdiscectomy. Comparable results were found for pain and back pain and rehabilitation [3,7-9]. It was postulated that patients
post-op
Dunn’s
2.3 (1.9) " 0.4033 ; 2.2 (2.5)
0.0189
?
0.3660
?
0.9999
?
0.9999
?
1.4 (2.1) " 0.6414 ; 1.0 (1.7)
FU
Kruskal Wallis
1.0 (1.3) " 0.6537 ; 1.3 (1.7)
0.0004
1.2 (1.8) " 0.8530 ; 1.0 (1.6)
0.0153 <0.0001
<0.0001
with a competent fibrous ring with defects <6 mm might be candidates for sequestrectomy [6]. However, the current literature does not provide a clear recommendation for the treatment of patients with lumbar disc herniation. Long-term comparative prospective randomized studies focusing on reherniation rates and long-term clinical outcomes including back and leg pain need to be published before making a recommendation of sequestrectomy in favor of microdiscectomy in cases of lumbar disc herniation. However, no publication was found regarding driving ability and the correlation with the surgical method for lumbar disc herniation. BRT and recommendations for driving resumption have been studied in the context of several lumbar surgeries, but no study has investigated BRT comparing sequestrectomy and microdiscectomy [12,14,15]. The authors of the published articles resumed that it seems safe for patients to drive a car immediately after surgery, because BRT improved rapidly after the intervention. They based their recommendation on the result that BRT improved after surgery in patients who frequently drove cars before the surgery. Among other factors influencing driving ability (visual acuity, amount of sleep, etc.), many publications stated that BRT is the key parameter (synonyms: driving reaction time, brake response time) [12-17] BRT was defined as the time interval between a stimulus (e.g. visual stimulus: red traffic light) and the application of sufficient pressure to the brake pedal. BRT as investigated in our study includes neurologic reaction time, foot transfer time and the time necessary to put pressure on the pedal. This is well in line with previous research published in the field of driving safety [12– 17] Reaction is considered as a complex task [18–20]. It consists of various psychomotor processes and is defined as the amount of time an individual takes to respond and complete a movement after a stimulus has been presented [18–20]. In our study, brake reaction time was defined as the amount of time it took for the participant to move his or her right foot from the accelerator to the brake pedal after the red light lit up on the driving simulator. We did not differentiate between reaction time and brake time, because in daily traffic the difference does not really has an impact
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Table 3 Longitudinal and cross-sectional comparison of BRT in patients with microdiscectomy and sequestrectomy (pre-op: preoperative; post-op: postoperative; FU: follow-up). Data in frames: p values of longitudinal (a = 0.05) and cross-sectional (a = 0.05) comparison. Data in frames: brake response time as mean (SD) [msec].
Microdisectomy Mann-Whitney U Sequestrectomy
pre-op
Tukey’s
749 (233) " 0.2155 ; 852 (561)
0.0541
?
0.1591
?
on avoiding an accident or not. However, from a scientific point of view, the difference as described by other authors is very interesting field of research [21] Several administrative bodies also provide recommendations regarding safe driving. The use of opioid analgesics has been associated with an increased odds of unsafe driving [22], and the FDA advises all patients taking opioids not to drive or operate heavy machinery because of drowsiness associated with this medication [23]. However, these advices were not published for ordinary passenger cars. Pain medication does not seem to have a significant influence on BRT [14–17]. Nilson showed that chronic pain reduces driving abilities but not opioids per se [24]. In our study we also found no correlation between BRT and pain medication. Therefore, no restrictions have been published outside of the US regarding the use of opioids and driving. Although, there was a reduction in BRT in longitudinal comparison in both patient samples, BRT´s of both patient samples were longer than BRT in healthy controls. The explanation for this phenomenon might be, because pain and muscle weakness cause reflex inhibition [25]. General anesthesia has an impact on BRT, but the impairing effects of general anesthesia should no longer persist after 24 h [15]. Published data showed that spinal pathologies such as radiculopathy and degenerative spinal pathologies cause a delay in the neural signal transfer, and this may result in a longer BRT in in both patient samples throughout the whole study period [12,14,15]. The National Highway Traffic Safety Administration (USA) recommends that drivers have at least 4/5 strength in both upper extremities and right lower extremity to drive safely, with 4/5 strength defined as movement against gravity and some resistance [26]. However, such recommendations are not published outside of the US and published data showed that BRT of patients with neurological impairment like foot drop caused by lumbar disc herniation show similar BRT’s compared with patients without foot drop caused by lumbar disc herniation [14,15]. Limitations of our study are that the patient samples are rather small. However, the patient groups are comparable to other studies giving their recommendations on driving safety after interventions [12,14,15]. We had no drop outs in our patient samples. Another limitation is that a longer follow-up period would show the trend of BRT in both patient samples in the long term. Although our results did not show significant differences in both patient samples, a positive effect of both surgical techniques for lumbar disc herniation could be shown. The decrease of BRT in the sequestrectomy group was higher compared to the microdiscectomy group. However, this difference was not statistically significant. There was no statistical significant difference between BRT of healthy controls and BRT of sequestrectomy and microdiscectomy group at 30 days follow up, proofing a positive effect of both surgical procedures on BRT values. 5. Conclusions Patients frequently ask spinal surgeons when they can return to driving after a surgery. Until now, there are no standard guidelines that surgeons can use to advise patients which surgical method
post-op
Tukey’s
694 (223) " 0.9997 ; 693 (173)
0.0847
?
0.06275
?
FU
ANOVA
610 (145) " 0.9404 ; 630 (98)
0.0333
0.0405
(sequestrectomy or microdiscectomy) is recommended to increase driving safety after the surgery. Although BRT rapidly reduces immediately after both surgical techniques, physicians should also consider all other variables who affect driving safety and discuss them with their patients. On the basis of our findings it is concluded that no driving abstinence is recommended for both patient samples, because most of the patients drive a car before the surgery. A positive effect of both surgical methods could be found on driving safety. The patients should be instructed and aware that their BRT will be significant longer 30 days after surgery. After period 30 days BRT of sequestrectomy and microdiscectomy patients are comparable to healthy people. Informed consent Informed consent was obtained from all individual participants included in the study. Ethical approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (Ethikkomission der Medizinischen Universität Innsbruck UN4004) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Declaration of Competing Interest The authors declare that they have no conflict of interest. This study was funded by Medical University Innsbruck. All other authors are paid employees of Medical University of Innsbruck. The authors declare that the material within the submitted paper has not been and will not be submitted for publication elsewhere, including electronically in the same form, in English or in any other language, without the written consent of the copyrightholder. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jocn.2019.11.041. References [1] Campbell P, Wynne-Jones G, Muller S, Dunn KM. The influence of employment social support for risk and prognosis in nonspecific back pain: a systematic review and critical synthesis. Int Arch Occup Environ Health 2013;86:119–37. https://doi.org/10.1007/s00420-012-0804-2. [2] Frymoyer JW, Pope MH, Clements JH, Wilder DG, MacPherson B, Ashikaga T. Risk factors in low-back pain. An epidemiological survey. J Bone Joint Surg Am 1983;65:213–8. [3] Azarhomayoun A, Chou R, Shirdel S, Lakeh MM, Vaccaro AR, Rahimi-Movaghar V. Sequestrectomy versus conventional microdiscectomy for the treatment of a
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M. Thaler et al. / Journal of Clinical Neuroscience 72 (2020) 214–218 lumbar disc herniation: a systematic review. Spine 2015;40:E1330–9. https:// doi.org/10.1097/brs.0000000000001174. Weinstein JN, Lurie JD, Tosteson TD, Tosteson AN, Blood EA, Abdu WA, et al. Surgical versus nonoperative treatment for lumbar disc herniation: four-year results for the Spine Patient Outcomes Research Trial (SPORT). Spine 2008;33:2789–800. https://doi.org/10.1097/BRS.0b013e31818ed8f4. Huang T, Tian Z, Li M, Zheng W, Zhang L, Chen J, et al. Sequestrectomy versus microdiscectomy in the treatment of lumbar disc herniation: a meta-analysis. Int J Clin Exp Med 2015;8:7261–9. Fakouri B, Shetty NR, White TC. Is sequestrectomy a viable alternative to microdiscectomy? A systematic review of the literature. Clin Orthop Relat Res 2015;473:1957–62. https://doi.org/10.1007/s11999-014-3904-3. Barth M, Weiss C, Thome C. Two-year outcome after lumbar microdiscectomy versus microscopic sequestrectomy: part 1: evaluation of clinical outcome. Spine 2008;33:265–72. https://doi.org/10.1097/BRS.0b013e318162018c. Barth M, Diepers M, Weiss C, Thome C. Two-year outcome after lumbar microdiscectomy versus microscopic sequestrectomy: part 2: radiographic evaluation and correlation with clinical outcome. Spine 2008;33:273–9. https://doi.org/10.1097/BRS.0b013e31816201a6. Thome C, Barth M, Scharf J, Schmiedek P. Outcome after lumbar sequestrectomy compared with microdiscectomy: a prospective randomized study. J Neurosurg Spine 2005;2:271–8. https://doi.org/10.3171/ spi.2005.2.3.0271. Schick U, Elhabony R. Prospective comparative study of lumbar sequestrectomy and microdiscectomy. Minim Invasive Neurosurg 2009;52:180–5. https://doi.org/10.1055/s-0029-1237379. Boyaci S, Aksoy K. Long-term clinical outcome of the lumbar microdiscectomy and fragmentectomy: a prospective study. Neurosurg Quart 2016;26:109–15. Al-khayer A, Schueler A, Kruszewski G, Armstrong G, Grevitt MP. Driver reaction time before and after treatment for lumbar radiculopathy. Spine 2008;33:1696–700. https://doi.org/10.1097/BRS.0b013e31817b5bb7. Pierson JL, Earles DR, Wood K. Brake response time after total knee arthroplasty: when is it safe for patients to drive?. J Arthroplasty 2003;18:840–3.
[14] Thaler M, Lechner R, Foedinger B, Haid C, Kavakebi P, Galiano K, et al. Driving reaction time before and after surgery for disc herniation in patients with preoperative paresis. Spine J 2015;15:918–22. https://doi.org/10.1016/j. spinee.2013.06.052. [15] Thaler MLR, Foedinger B, Haid C, Kavakebi P, Galiano K, Obwegeser A. Driving reaction time before and after surgery for lumbar disc herniation in patients with radiculopathy. Eur Spine J 2012. [16] Lechner R, Thaler M, Krismer M, Haid C, Obernauer J, Obwegeser A. Driving reaction time before and after anterior cervical fusion for disc herniation: a preliminary study. Eur Spine J 2013;22:1517–21. [17] Liebensteiner MC, Birkfellner F, Thaler M, Haid C, Bach C, Krismer M. Driving reaction time before and after primary fusion of the lumbar spine. Spine 2010;35:330–5. https://doi.org/10.1097/BRS.0b013e3181b8e11a. [18] Spirduso WW. Reaction and movement time as a function of age and physical activity level. J Gerontol 1975;30:435–40. [19] Retchin SM, Cox J, Irwin L. Performance-based measurements among elderly drivers and nondrivers. J Am Geriatr Soc 1988;36:813–9. [20] Morrison RW, Swope JG, Halcomb CG. Movement time and brake pedal placement. Hum Factors 1986;28:241–6. [21] Holt G, Kay M, McGrory R, Kumar C. Emergency brake response time after first metatarsal osteotomy. JBJS 2008;90:1660–4. [22] Dubois S, Bédard M, Weaver B. The association between opioid analgesics and unsafe driving actions preceding fatal crashes. Accid Anal Prev 2010;42:30–7. [23] Administration UFD (2016) Risk evaluation and mitigation strategy (REMS) for extended-release and long-acting opioids; 2012. [24] Nilsenl HK, Landrøl NI, Kaasal S, Jenssenl GD, Fayersl P, Borchgrevinkl PC. Driving functions in a video simulator in chronic non-malignant pain patients using and not using codeine. Eur J Pain 2011;15:409–15. [25] Stokes M, Young A. The contribution of reflex inhibition to arthrogenous muscle weakness. Clin Sci (Lond) 1984;67:7–14. [26] Wang C, Kosinski C, Schwartzberg J. Physician’s guide to assessing and counseling older drivers. Shanklin A 2003.
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Clinical study
Brake reaction time before and after surgery for patients with sequestrectomy versus conventional microdiscectomy Martin Thaler a,⇑, David Putzer b,1, Richard Lindtner c, Dietmar Krappinger c, Christian Haid a, Alois Obwegeser d, Ricarda Lechner a a
Department of Orthopaedic Surgery, Medical University Innsbruck, Innsbruck, Austria Department of Orthopaedic Surgery, Experimental Orthopaedics, Medical University Innsbruck, Innsbruck, Austria Department of Trauma Surgery, Medical University Innsbruck, Innsbruck, Austria d Tiroler Landeskliniken, Innsbruck, Austria b c
a r t i c l e
i n f o
Article history: Received 14 August 2019 Accepted 30 November 2019
Keywords: Brake reaction time Sequestrectomy Lumbar disc surgery Disectomy Impairment of reaction time
a b s t r a c t The aim of this study was to compare the effects of sequestrectomy versus conventional microdiscectomy on breaking response time (BRT) for lumbar disc herniation (LDH). BRT is the key factor for return to drive recommendations after surgery. A prospective clinical study was conducted. Patients aged 25–65 years who underwent surgery for lumbar disc herniation and held a valid motorcar driving license were recruited in a single institution. The patients were assessed before surgery, immediately after the surgery and at the follow up examination 30 days post-surgery. BRT was measured using a driving simulator, a visual analogue scale (VAS) was used for pain assessment. BRT values were compared with BRT values of a healthy control group. In patients treated with microdiscectomy BRT reduced from 749 (±223) msec before surgery to 649 (±223) msec immediately after the surgery. In the sequestrectomy group BRT reduced from 852 (±561) msec before surgery to 693 (±173) msec immediately after the surgery. BRT at follow up was 610 (±145) msec for patients treated with microdiscectomy and 630 (±98) msec for patients operated with sequestrectomy. BRT for healthy controls was 487 (±116) msec. Pain improved significantly for both patient samples. Sequestrectomy and microdiscectomy were associated with similar effects on pain and BRT after surgery. There was no statistically significant difference between BRT of both patient samples at 30 days follow up examination. Both surgical techniques showed a positive effect on BRT. No statistically significant difference between sequestrectomy and microdiscectomy on BRT could be found. Ó 2019 Elsevier Ltd. All rights reserved.
1. Introduction Previous published studies indicated that 60–80% of humans would suffer from back pain during their lifetime [1], and 2%-10% of them need surgical treatment for sciatica [2]. Surgery for lumbar disc herniation (LDH) is the most common surgical procedure performed for radiculopathy [3]. Most patients with back pain and radiating pain undergo standard microdiscectomy with the removal of the free disc fragments followed by aggressive or conservative excision of the intervertebral disc [4]. Another encouraging surgical method is sequestrectomy, with the removal of only
⇑ Corresponding author at: Medical University Innsbruck, Department of Orthopaedic Surgery, Anichstr. 35, A-6020 Innsbruck, Austria. E-mail address: [email protected] (M. Thaler). 1 ORCID: 0000-0001-9439-0051. https://doi.org/10.1016/j.jocn.2019.11.041 0967-5868/Ó 2019 Elsevier Ltd. All rights reserved.
extruded disc fragments and any loose pieces in the disc space without clearing the intervertebral disc. There are several publications comparing microdiscectomy and sequestrectomy [3-9]. Most of these reports revealed comparable results regarding reherniation rates, pain after surgery, functional outcome and complication rates [3,7-9]. Some studies postulated that sequestrectomy is associated with a slightly better clinical outcome regarding radicular pain at the short term follow up [7] and less postoperative analgesic consumption [7,10,11], the rate of reherniation was reported to be slightly higher in microdiscectomy patients. However, a potential disadvantage of sequestrectomy versus conventional microdiscectomy is a higher risk of recurrent disc herniation and potential advantages are more preserved architecture of the spine and less back pain (LBP) after surgery [7,10,11] Patients commonly inquire about resuming everyday social activities like return to work or driving after surgery. The ability
M. Thaler et al. / Journal of Clinical Neuroscience 72 (2020) 214–218
to return to drive a car after surgery is an important issue in terms of quality of life and maintain social life activities. Breaking response time (BRT) is the most important factor responsible for driving safety [12,13]. BRT has already been studied in patients with lumbar disc surgery [14,15] demonstrating a significant reduction of BRT after the surgery and a positive impact on driving safety after surgery. The authors based their recommendations regarding return to driving on the patient’s preoperative data and recommended to return to drive after discharge from hospital. However, no data was found comparing sequestrectomy and microdiscectomy on patients driving ability were found. Therefore, the objective of the current study was to compare BRT after sequestrectomy and microdiscectomy. We also investigated BRT in both patient samples on longitudinal comparison regarding preoperative (PreOP), immediately postoperative and 4 weeks postoperative (PostOP) BRT values and compared BRT of both patient samples with the BRT of healthy controls.
215
light until the participant pressed the brake pedal was recorded in milliseconds (msec). Each patient performed three dry runs. Then BRT was measured ten times. Pain was measured for all patients with a Visual Analogue Scale (VAS), ranging from 0 for no pain to 10 for severe pain on each test occasion. Driving frequency (never, once a month, once a week, and daily) and intake of analgesics was recorded on each test occasion. Data were processed using the Graph Pad Prism (Prism 7, Graph Pad Software Inc., San Diego, CA, USA). Driving reaction time were not normally distributed. The Kruskal Wallis test was used to test for longitudinal differences in BRT. P-values <0.05 were defined as statistically significant. If significance was seen Dunn’s tests were performed for post hoc analysis (pre-/post-op comparison, postop/FU comparison). P-values <0.05 were defined as statistically significant. Mann–Whitney U Test (alpha level of 0.05) was used for comparison between single time points of both groups.
2. Materials and methods 3. Results This study was approved by the university´s ethics committee and all procedures followed were in accordance with the ethical standards of the Helsinki Declaration of 1975, as revised in 2000. Written informed consent was obtained from each study patient. Sixty consecutive patients scheduled to surgery for a single-level lumbar disc herniation were included in the present study. In a randomized setup 30 patients were treated with microdiscectomy and then 30 patients were treated with sequestrectomy. All included patients had a valid driving license. Patients suffering from other diseases like central neurological disorders, acute trauma, cauda equina syndrome, pathologic or infectious diseases of the spine, stenosis of the spinal canal, spondylolisthesis, scoliosis or kyphosis, presence of concomitant spinal disease and previous spinal surgery were excluded from the study. All patients failed to improve with non-surgical therapy and presented with pain due to lumbar disc herniation lasting >6–8 weeks. In all patients magnetic resonance imaging (MRI) confirmed disc herniation. Patients with free disc fragments, subligamentary herniations and transannular herniations (herniation in continuity with the disc space) were included. The patients received either a standard microdiscectomy with removal of herniated disc material plus disc tissue from the intervertebral space or a sequestrectomy with removal of the herniated disc material only. Total intravenous anaesthesia was used in all patients. In microdiscectomy the disc space was entered with a rongeur to remove as much of the nucleus, i.e., the loose intradiscal tissue, as possible. No curettes or similar instruments were used intradiscally to avoid injury to the cartilaginous endplates or the annulus. In the sequestrectomy-treated group, only the herniated disc material was removed and the intervertebral disc space was not entered by any instrument. Thus, the central nucleectomy was the actual difference between the two surgical procedures. The control group consisted of 31 healthy subjects (19 females, 12 males; mean age 52 years; SD 7.7 years) with a valid driving license, at least 10 years of driving experience and no history of spinal pathology [16]. All 4 surgeries were performed by 4 experienced neurosurgeons For the BRT measurements a driving simulator as described previously was used [14,15,17]. When the accelerator was fully pressed by the participant, a green signal light lit up, indicating that the participant was driving in a ready to brake fashion. Randomly, after 5–10 s a red signal light and simultaneously the electronic clock were activated. The patients were advised to brake with their right foot as quick as possible when a red signal light appeared. The time interval from the appearance of the red signal
The first examination (preoperative: pre-op) was performed 1 day (median, range 1–6 days) before surgery, the second examination before hospital discharge (3 days (median, range 2–7 days)) and the third test at follow-up (FU: 31 days (median, range 20–58)) examination. Two patients in the microdisectomy group underwent a second stage procedure, because the initial decompression was not sufficient layer discectomy (Table 1). One patient showed a cerebrospinal fluid (CSF) leakage after the surgery, one showed an insufficient initial decompression and had to be revised. In the sequestrectomy group one patients had a CSF after surgery and had to be revised. Demographic and baseline characteristics of the patients are shown in Table 1. When comparing the microdisectomy group with the sequestrectomy group no difference (p > 0.05 U-Test) could be found between patients operated with the seqestrectomy and the microdiscectomy technique assessing VAS for back pain and VAS for leg pain as well preoperatively, postoperatively and at FU (Table 2 vertical comparisons). A significant difference could (p < 0.01 KS-Test) be found when analyzing the differences between each time step (pre-op, post-op and FU) for the microdisectomy group and the seqeustrectomy group for both scores assessed (Table 2 horizontal comparisons). There was no significant difference between pre and postoperative VAS regarding pack pain in both groups (p > 0.5 Dunn’s Test). After 6 weeks a significant lower VAS back (p = 0.0189 Dunn’s Test) was recorded for patients who underwent microdisectomy surgery (Table 2). Patients of both groups showed a significant lower VAS leg after surgery (p = 0.0001 Dunn’s Test) compared to preoperative assessed VAS leg (Table 2). Comparing BRT after ctomy to a control group (487 SD(116) N = 31) of healthy subjects statistical significant higher values was found preoperatively (p < 0.0001 Tukey’s Test both groups) and postopereatively (p = 0.0023 sequestrectomy group and p = 0.0025 microdisectomy group, Tukey’s Test) for the patients with disc herniation (Fig. 1). No difference could be found between patients operated with the seqestrectomy and the microdiscectomy technique preoperatively (p = 0.2155, Tukey’s Test), postoperatively (p = 0.9997, Tukey’s Test) and at FU (p = 0.9404 Tukey’s Test). At a FU period of 30 days no difference could be found between patients operated with sequestrectomy and the control group (p = 0.1136, Tukey’s Test) and patients operated with microdiscectomy and the control group (p = 0.0523, Tukey’s Test) (Fig. 1).
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Table 1 Comparison of demographic data of patients operated with microdiscectomy and sequestrectomy. Data is presented as mean (SD). Microdiscectomy
Sequestrectomy
Controls
45 (10) 16 14
51 (13) 10 20
52 (8) 19 12
L2/L3 L3/L4 L4/L5 L5/S1
0 4 14 14
1 3 16 10
CSF
1
1
Age (mean (sd)) [y] Female [n] Male [n] Herniation level
Complications
Table 2 Longitudinal and cross-sectional comparison of VAS in patients with microdiscectomy and sequestrectomy (pre-op: preoperative; post-op: postoperative; FU: follow-up). Data in frames: p values of longitudinal (a = 0.05) and cross-sectional (a = 0.05) comparison. Data in frames: brake response time as mean (SD).
VAS back Microdisectomy Mann-Whitney U Sequestrectomy VAS leg Microdisectomy Mann-Whitney U Sequestrectomy
pre-op
Dunn’s
3.4 (2.7) " 0.7584 ; 3.2 (2.7)
0.5100
?
0.5390
?
0.0001
?
<0.0001
?
4.2 (2.7) " 0.4364 ; 4.7 (2.5)
Fig. 1. Mean and standard deviation (bars) of BRT in msec of sequestrectomy and mircodisectomy group in comparison to the control group. ****Indicates a p < 0.0001, *** indicates p > 0.0002, ** indicates p > 0.002, * indicates p > 0.03.
Comparing BRT in the longitudinal follow ups a statistically significant difference was seen for patients operated with sequestrectomy and microdiscectomy (p > 0.05, Table 3, ANOVA with Tukey’s multiple comparisons test). Post-hoc analysis was set to the alpha level of 0.05 and revealed no significant difference between BRT pre-op and BRT post-op and between BRT post-op and BRT at follow up time for patients which underwent sequestrectomy or microdicectomy after disc herniation (Table 3) A significant difference was found between pre-op BRT and follow up period for both groups (p = 0.0375 for sequestrectomy and p = 0.0264 for disectomy). No correlation was found between VAS for back or leg pain and BRT at all subsequent time points of measurement. No correlation between pain medication and BRT was found. 4. Discussion Several articles provide a comparison between sequestrectomy and microdiscectomy. Comparable results were found for pain and back pain and rehabilitation [3,7-9]. It was postulated that patients
post-op
Dunn’s
2.3 (1.9) " 0.4033 ; 2.2 (2.5)
0.0189
?
0.3660
?
0.9999
?
0.9999
?
1.4 (2.1) " 0.6414 ; 1.0 (1.7)
FU
Kruskal Wallis
1.0 (1.3) " 0.6537 ; 1.3 (1.7)
0.0004
1.2 (1.8) " 0.8530 ; 1.0 (1.6)
0.0153 <0.0001
<0.0001
with a competent fibrous ring with defects <6 mm might be candidates for sequestrectomy [6]. However, the current literature does not provide a clear recommendation for the treatment of patients with lumbar disc herniation. Long-term comparative prospective randomized studies focusing on reherniation rates and long-term clinical outcomes including back and leg pain need to be published before making a recommendation of sequestrectomy in favor of microdiscectomy in cases of lumbar disc herniation. However, no publication was found regarding driving ability and the correlation with the surgical method for lumbar disc herniation. BRT and recommendations for driving resumption have been studied in the context of several lumbar surgeries, but no study has investigated BRT comparing sequestrectomy and microdiscectomy [12,14,15]. The authors of the published articles resumed that it seems safe for patients to drive a car immediately after surgery, because BRT improved rapidly after the intervention. They based their recommendation on the result that BRT improved after surgery in patients who frequently drove cars before the surgery. Among other factors influencing driving ability (visual acuity, amount of sleep, etc.), many publications stated that BRT is the key parameter (synonyms: driving reaction time, brake response time) [12-17] BRT was defined as the time interval between a stimulus (e.g. visual stimulus: red traffic light) and the application of sufficient pressure to the brake pedal. BRT as investigated in our study includes neurologic reaction time, foot transfer time and the time necessary to put pressure on the pedal. This is well in line with previous research published in the field of driving safety [12– 17] Reaction is considered as a complex task [18–20]. It consists of various psychomotor processes and is defined as the amount of time an individual takes to respond and complete a movement after a stimulus has been presented [18–20]. In our study, brake reaction time was defined as the amount of time it took for the participant to move his or her right foot from the accelerator to the brake pedal after the red light lit up on the driving simulator. We did not differentiate between reaction time and brake time, because in daily traffic the difference does not really has an impact
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Table 3 Longitudinal and cross-sectional comparison of BRT in patients with microdiscectomy and sequestrectomy (pre-op: preoperative; post-op: postoperative; FU: follow-up). Data in frames: p values of longitudinal (a = 0.05) and cross-sectional (a = 0.05) comparison. Data in frames: brake response time as mean (SD) [msec].
Microdisectomy Mann-Whitney U Sequestrectomy
pre-op
Tukey’s
749 (233) " 0.2155 ; 852 (561)
0.0541
?
0.1591
?
on avoiding an accident or not. However, from a scientific point of view, the difference as described by other authors is very interesting field of research [21] Several administrative bodies also provide recommendations regarding safe driving. The use of opioid analgesics has been associated with an increased odds of unsafe driving [22], and the FDA advises all patients taking opioids not to drive or operate heavy machinery because of drowsiness associated with this medication [23]. However, these advices were not published for ordinary passenger cars. Pain medication does not seem to have a significant influence on BRT [14–17]. Nilson showed that chronic pain reduces driving abilities but not opioids per se [24]. In our study we also found no correlation between BRT and pain medication. Therefore, no restrictions have been published outside of the US regarding the use of opioids and driving. Although, there was a reduction in BRT in longitudinal comparison in both patient samples, BRT´s of both patient samples were longer than BRT in healthy controls. The explanation for this phenomenon might be, because pain and muscle weakness cause reflex inhibition [25]. General anesthesia has an impact on BRT, but the impairing effects of general anesthesia should no longer persist after 24 h [15]. Published data showed that spinal pathologies such as radiculopathy and degenerative spinal pathologies cause a delay in the neural signal transfer, and this may result in a longer BRT in in both patient samples throughout the whole study period [12,14,15]. The National Highway Traffic Safety Administration (USA) recommends that drivers have at least 4/5 strength in both upper extremities and right lower extremity to drive safely, with 4/5 strength defined as movement against gravity and some resistance [26]. However, such recommendations are not published outside of the US and published data showed that BRT of patients with neurological impairment like foot drop caused by lumbar disc herniation show similar BRT’s compared with patients without foot drop caused by lumbar disc herniation [14,15]. Limitations of our study are that the patient samples are rather small. However, the patient groups are comparable to other studies giving their recommendations on driving safety after interventions [12,14,15]. We had no drop outs in our patient samples. Another limitation is that a longer follow-up period would show the trend of BRT in both patient samples in the long term. Although our results did not show significant differences in both patient samples, a positive effect of both surgical techniques for lumbar disc herniation could be shown. The decrease of BRT in the sequestrectomy group was higher compared to the microdiscectomy group. However, this difference was not statistically significant. There was no statistical significant difference between BRT of healthy controls and BRT of sequestrectomy and microdiscectomy group at 30 days follow up, proofing a positive effect of both surgical procedures on BRT values. 5. Conclusions Patients frequently ask spinal surgeons when they can return to driving after a surgery. Until now, there are no standard guidelines that surgeons can use to advise patients which surgical method
post-op
Tukey’s
694 (223) " 0.9997 ; 693 (173)
0.0847
?
0.06275
?
FU
ANOVA
610 (145) " 0.9404 ; 630 (98)
0.0333
0.0405
(sequestrectomy or microdiscectomy) is recommended to increase driving safety after the surgery. Although BRT rapidly reduces immediately after both surgical techniques, physicians should also consider all other variables who affect driving safety and discuss them with their patients. On the basis of our findings it is concluded that no driving abstinence is recommended for both patient samples, because most of the patients drive a car before the surgery. A positive effect of both surgical methods could be found on driving safety. The patients should be instructed and aware that their BRT will be significant longer 30 days after surgery. After period 30 days BRT of sequestrectomy and microdiscectomy patients are comparable to healthy people. Informed consent Informed consent was obtained from all individual participants included in the study. Ethical approval All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee (Ethikkomission der Medizinischen Universität Innsbruck UN4004) and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Declaration of Competing Interest The authors declare that they have no conflict of interest. This study was funded by Medical University Innsbruck. All other authors are paid employees of Medical University of Innsbruck. The authors declare that the material within the submitted paper has not been and will not be submitted for publication elsewhere, including electronically in the same form, in English or in any other language, without the written consent of the copyrightholder. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. Appendix A. Supplementary data Supplementary data to this article can be found online at https://doi.org/10.1016/j.jocn.2019.11.041. References [1] Campbell P, Wynne-Jones G, Muller S, Dunn KM. The influence of employment social support for risk and prognosis in nonspecific back pain: a systematic review and critical synthesis. Int Arch Occup Environ Health 2013;86:119–37. https://doi.org/10.1007/s00420-012-0804-2. [2] Frymoyer JW, Pope MH, Clements JH, Wilder DG, MacPherson B, Ashikaga T. Risk factors in low-back pain. An epidemiological survey. J Bone Joint Surg Am 1983;65:213–8. [3] Azarhomayoun A, Chou R, Shirdel S, Lakeh MM, Vaccaro AR, Rahimi-Movaghar V. Sequestrectomy versus conventional microdiscectomy for the treatment of a
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