Health-related quality of life (HRQoL) following transforaminal percutaneous endoscopic discectomy (TPED) for lumbar disc herniation: A prospective cohort study

Abstract

BACKGROUND:

Lumbar discectomy is among the most frequently performed procedures in spinal surgery. Transforaminal percutaneous endoscopic discectomy (TPED) is a minimally invasive technique that gains ground among surgeons in the recent years. TPED has been studied in terms of effectiveness, however little is known about its overall impact on health-related quality of life (HRQoL) of the patients.

OBJECTIVE:

To investigate the progress of HRQoL following TPED.

PATIENTS AND METHODS:

Seventy-six (76) patients were enrolled in the study. Mean age was 56.5 $\pm$ 12.1 years with 38 (50%) males and 38 (50%) females. All patients underwent TPED at L3-L4 (27.6%), L4-L5 (52.6%) and L5-S1 (19.7%). SF-36 was used for the assessment of HRQoL preoperatively and at 6 weeks, at 3, 6 and 12 months after the procedure.

RESULTS:

All aspects of SF-36 questionnaire showed statistically significant improvement one year after the procedure ( $p<$ 0.001). Role limitations due to physical problems, bodily pain and role limitations due emotional problems showed the highest improvement, followed by physical functioning, vitality, social functioning, mental health and general health.

CONCLUSIONS:

TPED for lumbar disc herniation is associated with significant improvement in all aspects of health-related quality of life within 6 weeks postoperatively and the improvement remains significant one year after surgery, as measured by the SF-36 questionnaire.

Keywords

Lumbar hernia discectomy endoscopy transforaminal health-related quality of life

Table 1
SF-36 scores preoperatively and at 6 weeks, 3 months, 6 months and 12 months postoperatively

SF-36 (%)	Pre op	6 w	3 mo	6 mo	12 mo
PF	47.4 $\pm$ 7.2	64.3 $\pm$ 3.5	71.7 $\pm$ 4.2	80.3 $\pm$ 4.6	82.9 $\pm$ 4.2
RP	22.0 $\pm$ 5.7	57.4 $\pm$ 4.3	65.8 $\pm$ 4.0	70.5 $\pm$ 4.1	75.0 $\pm$ 4.6
BP	31.4 $\pm$ 5.4	47.5 $\pm$ 5.3	52.8 $\pm$ 5.7	62.4 $\pm$ 6.5	77. 7 $\pm$ 5.9
GH	64.5 $\pm$ 4.7	65.5 $\pm$ 4.7	66.7 $\pm$ 4.9	68.3 $\pm$ 4.9	69.1 $\pm$ 5.0
VT	46.3 $\pm$ 5.1	58.3 $\pm$ 5.7	63.3 $\pm$ 5.8	76.3 $\pm$ 5.8	79.7 $\pm$ 5.8
SF	50.7 $\pm$ 6.7	64.0 $\pm$ 7.1	66.0 $\pm$ 6.7	80.0 $\pm$ 6.3	84.0 $\pm$ 6.7
RE	50.9 $\pm$ 7.1	68.0 $\pm$ 7.0	76.5 $\pm$ 6.9	87.1 $\pm$ 6.4	90.1 $\pm$ 5.5
MH	70.8 $\pm$ 7.6	72.6 $\pm$ 7.2	75.3 $\pm$ 7.0	78.0 $\pm$ 6.4	80.1 $\pm$ 5.8

${}^{*}$ Level of significance is determined at a $=$ 0.05. P values less than 0.05 ( $p<$ 0.05) are considered to be significant. P values referring to the comparison with the immediately preceding time interval were statistically significant ( $p<$ 0.001) for all the SF-36 aspects included in the Table. P values for the comparison with the baseline measurements remained significant ( $p<$ 0.001) for all the aspects and all the time points. PF: physical functioning, RP: role limitations due to physical problems, BP: bodily pain, GH: general health perceptions, VT: vitality, energy, fatigue, SF: social functioning, RE: role limitations due to emotional problems, MH: mental health.

1. Introduction

Lumbar discectomy is the most frequently performed procedure by spinal surgeons and the main indication is radiculopathy of the lower limbs [1, 2]. The surgical technique has evolved in the past century, from the gold standard open microdiscectomy to minimally invasive spine surgery, such as endoscopy [3]. Transforaminal percutaneous endoscopic discectomy (TPED) is a fairly new, innovative endoscopic technique. It gains access into the spinal canal through a posterolateral approach and enters the epidural space via the foramen and the anatomic triangle described by Kambin [4, 5]. TPED is less traumatic than open surgery, as it preserves dorsal musculature, bones and ligamentous structures. Scar tissue formation in the epidural space and its long-term complications are minimized [6]. Moreover, TPED has comparable effectiveness to standard open microdiscectomy and is associated with reduced blood loss, hospital stay and postoperative morbidity [7, 8].

Health is determined as a combination of several interacting factors in someone’s life (physical, mental, social) rather than the absence of illness [9]. Health status is, therefore, subjective according to each individual’s life. Instruments assessing health-related quality of life (HRQoL) are patient-oriented questionnaires, increasingly used in the literature for outcome assessment in different medical conditions or treatments. These measures may be generic or condition specific and quantify the health status of a patient in general or in association with specific disorders, respectively [10]. Spine surgery is no exception to this trend [11].

The Medical Outcomes Study Short Form Health-Survey Questionnaire (SF-36) is the most broadly applied health-status questionnaire and the most common generic HRQoL in the clinical assessment of spine surgery [12], tested for its validity, reliability and responsiveness [11, 12, 13]. SF-36 score assesses aspects such as functional ability, well-being and overall health [14]. It is a summarized form of 149 health related questions derived from the Medical Outcomes Study (MOS) [15]. SF-36 has been translated in several languages, in order to facilitate uniform, cross-cultural application and valid comparisons between studies [16, 17, 18]. The existence of normative data for specific populations constitutes SF-36 an appropriate tool in research and allows comparison between interventions, populations and medical conditions between different studies [12]. SF-36 is constructed by multi-item scales focused on eight different aspects of general health; physical functioning, role limitations due to physical problems, bodily pain, general health perceptions, vitality, energy and fatigue, social functioning, role limitations due to emotional problems and mental health. Generally, higher scores are associated with a better health status, ranging from 0 (worse possible health status) to 100 (best possible health status) [19].

Few previous studies have focused on the overall impact of the TPED in health-related quality of life (HRQoL), assessed by SF-36 score [20, 21]. Peng et al. (2009) showed a significant improvement in quality of life two years after TPED [20, 21]. Quality of life was assessed by SF-36 and the difference was significant for all the components at 6 months and 2 years after the procedure, except for general health. The intention of the present study is to estimate the progress of general health and well-being at 6 weeks, 3 months, 6 months and one year after TPED in adults diagnosed with lumbar disc herniation. Our primary hypothesis is that endoscopic discectomy, apart from its beneficial impact on the remission of radicular symptomatology, has an additional positive effect on HRQoL one year after the procedure.

2. Patients and methods

2.1 Patients’ selection

All patients admitted to our hospital with lumbar disc herniation that fulfilled the criteria for surgery were prospectively enrolled in the study. The patients agreed to participate in the study and signed an informed written consent. The study was approved by the medical council of the hospital and the local Ethics committee.

Inclusion criteria were: (i) radiculopathy (ii) positive nerve root tension sign (iii) sensory or motor neurologic lesion on clinical examination (iv) hernia confirmed by MRI of the lumbar spine, in compliance with clinical findings (v) failure of 12-week conservative treatment.

Exclusion criteria were: (i) noncontaminated disc hernia exceeding the one third of the spinal canal on the sagittal MRI scans (ii) sequestrated disc (iii) central or lateral recess spinal stenosis (iv) recurrent herniated disc or previous surgery at the affected level (iii) segmental instability or spondylolisthesis (iv) spinal tumor or infection (v) vertebral fracture.

Seventy six (76) patients fulfilled the aforementioned criteria and were enrolled in the study. Mean age was 56.5 $\pm$ 12.1 years with 38 (50%) males and 38 females (50%). Level of operation was L3-L4 (27.6%), L4-L5 (52.6%) and L5-S1 (19.7%). Baseline SF-36 values are presented at Table 1.

2.2 Methods

2.2.1 SF-36

The translated Greek form of the SF-36 questionnaire has been used in the present study, which has been previously tested for its construct validity [22] and normative data are provided for the general population in the urban area [23].

2.2.2 Surgical procedure

All patients enrolled in the study were subjected to Transforaminal Percutaneous Endoscopic Discectomy (TPED). The procedure was performed under local anesthesia and mild sedation, by the same experienced in the technique spinal surgeon. Patients were positioned at the lateral decubitus position, as seen in Fig. 1. Disinfection was applied to the surgical field and local anesthesia was initially performed at the needle entry point, about 11 cm away from midline. The needle was promoted to the foramen through the anatomic triangle described by Kambin [5]. The procedure took place under continuous fluoroscopic guidance. The level corresponding to the disc pathology was confirmed (Fig. 2). Mild sedation and analgesia with Fentanyl (Fentanyl ampule) were provided by the anesthesiologist. Three reamers of different size were, then, sequentially passed through the foramen (5.5, 6.5, 7.5 mm, Joimax System) (Fig. 3). The cannula and the endoscope were inserted, in a way that the nerve root was secured. Subsequently, the herniated disc was removed with graspers. The patients were monitored for the following hour in the wards and, then, mobilized. All patients were discharged 1 day after surgery. None of the patients presented perioperative complications.

Figure 1.

Lateral decubitus positioning of the patient.

Figure 2.

Verification of the operated level under fluoroscopic guidance.

Figure 3.

The needle is inserted and the first reamer (diameter 5.5 mm, Joimax) is passed through the foramen.

All the patients were subjected to a facsimile postoperative rehabilitation program of physiotherapy for 4 weeks.

2.2.3 Statistical analysis

Collected data were analyzed with the use of SPSS application (IBM, Version 13). Continuous variables (age, SF-36 components) are expressed as mean $\pm$ standard deviation (SD) and categorical variables (gender, level of operation) as percentages. The Kolmogorov-Smirnov test was utilized for normality analysis.

Student t-test and Wilcoxon test were utilized for the comparison of the quantitive-continuous variables (SF-36 components) in our dependent samples at each time point, for normal or not distribution, respectively. The level of significance is determined at a $=$ 0.05 or p value $=$ 0.05.

3. Results

Mean values for SF – 36 at baseline and at the determined intervals (6 weeks, 3 months, 6 months, and 12 months) are displayed at Table 1. The results were compared for statistical significant improvement between the different timepoints.

All the components of SF-36 follow a statistical significant improvement between each time interval ( $p<$ 0.001). Significant improvement is observed not only in the physical components of SF-36 (physical functioning, role limitations due to physical problems, bodily pain), but also in the mental components (social functioning, role limitations due to emotional problems, vitality, mental health and general health).

SF-36 profiles of our sample at the different time highlights are presented in Fig. 4, to facilitate comparison of the postoperative progress.

Figure 4.

SF-36 profile of the patients at different timepoints during the follow-up period. PF: physical functioning, RP: role limitations due to physical problems, BP: bodily pain, GH: general health perceptions, VT: vitality, energy, fatigue, SF: social functioning, RE: role limitations due to emotional problems, MH: mental health.

4. Discussion

Spinal surgery for lumbar disc herniation has evolved from traditional open procedures to minimally invasive techniques, such as TPED. Full endoscopic techniques are shown to be equal to effectiveness and clinical outcome when compared to gold standard microdiscectomy [6, 7]. Meanwhile, they seem to surpass microdiscectomy in terms of rehabilitation, as they are followed by a shorter postoperative work disability period (29 days vs 45 days) [6]. However, little research has been made so far to investigate the improvement of overall health status following TPED.

Grevitt et al. had tested the consistency of SF-36 with Oswsestry Disability Index (ODI) for low back pain in the clinical assessment of spinal surgery, including the minimally invasive technique of automated percutaneous lumbar discectomy. Statistical analysis showed significant correlation of the two measures, which was the strongest for bodily pain, physical and social function and the lowest for mental health [14]. However, the outcome of spinal surgery is determined by the interaction of both physical and psychologic factors [24]. Abnormal illness behavior interferes with someone’s perception of pain and disability. On top of that, emotional distress, especially when associated with a long-duration of radicular symptomatology, possibly undermines the outcome of spinal surgery [24, 25]. Disease specific measures, such as Oswestry Disability Index (ODI) or Visual Analogue Scales (VAS), fail to assess the impact of the psychologic profile on physical function and well-being. SF-36, however, provides a more personalized and global approach at baseline and during the follow-up period. The physical component of SF-36 (physical function, role physical and bodily pain) is best responsive to health status improvement in patients with sciatica under treatment, surgical or not [26].

In our study, baseline values of the SF-36 questionnaire were lower from the respective normative values for greek urban population, provided by Pappa et al. [23], for all the components. Patients suffering from spine pathology, especially those selected to undergo spine surgery, are characterized by generally worse preoperative SF-36 values not only in comparison with healthy individuals, but also in comparison with patients suffering from non specific low back pain and other musculoskeletal pathology [12]. At baseline, our findings are in consistence with the published normative data for patients diagnosed with disc hernia or suffering from sciatica [12, 26].

The present study suggests that patients underwent TPED for lumbar disc herniation are characterized by significantly higher values in all SF-36 components one year after the procedure compared to the preoperative status, fact that implies a positive impact of endoscopy on the overall health status and quality of life. The following (role limitations due to physical problems, bodily pain and role limitations due to emotional problems) showed the maximum improvement, especially role limitations due to physical problems, followed by physical functioning, vitality and social functioning. Mental and general health were, also, improved after the procedure, although their absolute change fluctuated in considerably lower levels.

Comparing our results with findings of Peng et al. [20], our population scored considerably higher values in physical functioning, role limitations due to physical problems, and vitality 6 months after the procedure, fact that could not be attributed to higher preoperative values and despite the older age of our population (56.5 vs 35.6 years) and the higher prevalence of female gender (50% vs 41.8%) [27]. However, during the follow-up period these differences were eliminated and, finally, reached similar levels with those described by Peng et al. within one year after surgery. Considering that the study did not included interval measurements between 6 months and two years and that the results are counterbalanced at the end of the follow-up period, we could assume that the beneficial outcome of TPED in quality of life is possibly achieved and stabilized within the first 12 months and retained the second year after the procedure. Further studies, however, are needed to claim this assumption.

Endoscopic spinal surgery for lumbar disc herniation induces an overall improvement of 88% and 83% in Visual Analogue Scale (VAS) for leg pain and Oswestry Disability Index (ODI) for low back pain, respectively, as it arises from a systematic review of literature by Nellensteijn et al. [7]. The improvement of quality of life in patients that underwent TPED for symptomatic lumbar disc hernia is attributed to increased functionality in everyday life, due to remission of radicular symptomatology and low back pain. SF-36 has been tested for its consistency with the condition specific measure of Oswestry Disability Index for low back pain and the correlation was the highest for the aspects of bodily pain and physical functioning [14]. In our study, the improvement of HRQoL is mainly attributed to the change in the status of pain and disability after the procedure. Our results are consistent with this conclusion, as the aspects role limitations due to physical problems and bodily pain show the highest absolute change from baseline to one year after the procedure.

Limitations of our study are the non inclusion of (i) comorbidities (ii) preoperative duration of symptomatology and (iii) other demographic characteristics apart from age and sex, such as education, social class, marital status etc, that have an impact on quality of life [27]. We do not have a control group that underwent another surgical procedure apart from TPED, because our primary intention was to (i) observe the progress of quality of life after the procedure and (ii) offer normative data for future studies. Nevertheless, the strict inclusion criteria and the different overall profile of the patients subjected to endoscopy (age, duration of symptoms, education, demographics) pose limitations to direct comparison with patients selected for open procedures.

5. Conclusions

Our study converges that TPED is associated with significant improvement in health-related quality of life a year after the procedure, as measured by SF-36 questionnaire. Patients scored significantly higher values in all SF-36 components ( $p<$ 0.001) within 6 weeks after TPED and the improvement remained significant one year after the procedure.

Conflict of interest

The authors report no conflict of interest concerning the materials or methods used in this study or the findings specified in this paper.

References

Weinstein

Tosteson

Lurie

Tosteson

Hanscom

Skinner

, et al. Surgical vs nonoperative treatment for lumbar disc herniation: the Spine Patient Outcomes Research Trial (SPORT): a randomized trial. JAMA. 2006; 296(20): 2441-50.

Blamoutier

. Surgical discectomy for lumbar disc herniation: surgical techniques. Orthop Traumatol Surg Res. 2013; 99(1 Suppl): S187-96. Doi: 10.1016/j.otsr.2012.11.005.

Postacchini

. Operative management of lumbar disc herniation: the evolution of knowledge and surgical techniques in the last century. Acta Neurochir Suppl. 2011; 108: 17-21. Doi: 10.1007/978-3-211-99370-5_4.

Kambin

Sampson

. Posterolateral percutaneous suction-excision of herniated lumbar intervertebral discs. Report of interim results. Clin Orthop Relat Res. 1986; 207: 37-43.

Kambin

Brager

. Percutaneous posterolateral discectomy. Anatomy and mechanism. Clin Orthop Relat Res. 1987; 223: 145-54.

Ruetten

Komp

Merk

Godolias

. Full-endoscopic interlaminar and transforaminal lumbar discectomy versus conventional microsurgical technique: a prospective, randomized, controlled study. Spine (Phila Pa 1976). 2008; 33(9): 931-9.

Nellensteijn

Ostelo

Bartels

Peul

van Tulder

. Transforaminal endoscopic surgery for symptomatic lumbar disc herniations: a systematic review of the literature. Eur Spine J. 2010; 19(2): 181-204. DOI: 10.1007/s00586-009-1155-x.

Mayer

Brock

. Percutaneous endoscopic lumbar discectomy (PELD). Neurosurg Rev. 1993; 16(2): 115-20.

Handbook of basic documents. 46th ed. Geneve: World Health Organization; World Health Organization.

10.

Guyatt

Feeny

Patrich

. Measuring health-related quality of life. Ann Intern Med. 1993; 118(8): 622-9.

11.

Bombardier

. Outcome assessements in the evaluation of treatment of spinal disorders. Introduction. Spine. 2000; 25(24): 3097-9.

12.

Zanoli

Jonsson

Stromgvist

. SF-36 scores in degenerative lumbar spine disorders: analysis of prospective data from 451 patients. Acta Orthop. 2006; 77(2): 298-306.

13.

Ware

Jr Bjorner

Kosinski

. Practical implications of item response theory and computerized adaptive testing: a brief summary on ongoing studies of widely used headache impact scales. Med Care. 2000; 38(9): II73-82.

14.

Grevitt

Khazim

Webb

Mulholland

Shepperd

. The short form-36 health survey questionnaire in spine surgery. J Bone Joint Surg Br. 1997; 79(1): 48-52.

15.

Tarlov

Ware

Greenfield

Nelson

Perrin

Zubkoff

. The Medical Outcomes Study. An application of methods for monitoring the results of medical care. JAMA. 1989; 262(7): 925-30.

16.

Ware

Keller

Gandek

Brazier

Sullivan

. Evaluating translations of health status questionnaires. Methods from the IQOLA project. International Quality of Life Assesment. Int J Technol Assess Health Care. 1995; 11(3): 525-51.

17.

Wagner

Gandek

Aaronson

Acquadro

Alonso

Apolone

, et al. Cross-cultural comparisons of the content of SF-36 translations across 10 countries: results from the IQOLA Project. International Quality of Life Assessment. J Clin Epidemiol. 1998; 51(11): 925-32.

18.

Bullinger

Alonso

Apolone

Leplege

Sullivan

Wood-Dauphinee

, et al. Translating helath status questionnaires and evaluating their quality: the IQOLA Project approach. International Quality of Life Assessment. J Clin Epidemiol. 1998; 51(11): 913-23.

19.

Ware

Snow

Kosinski

. (1993, 2000) SF-36 Health Survey: Manual and Interpretation Guide. Lincoln, RI: QualityMetric Inc.

20.

Peng

Yeo

Tan

. Percutaneous endoscopic lumbar discectomy: clinical and quality of life outcomes with a minimum 2 year follow-up. J Orthop Surg Res. 2009; 4: 20.

21.

Peng

Yeo

Tan

. Percutaneous endoscopic discectomy: clinical results and how it affects the quality of life. J Spinal Disord Tech. 2010; 23(6): 425-30.

22.

Anagnostopoulos

Niakas

Pappa

. Construct validation of the Greek SF-36 Health Survey. Qual Life Res. 2005; 14(8): 1959-65.

23.

Pappa

Kontodimopoulos

Niakas

. Validating and norming of the Greek SF-36 Health Survey. Qual Life Res. 2005; 14(5): 1433-8.

24.

Waddell

Morris

, Paola

Bircher

Finlayson

. A concept of illness tested as an improved basis for surgical decisions in low-back disorders. Spine (Phila Pa 1976). 1986; 11(7): 712-9.

25.

Carragee

. Psychological screening in the surgical treatment of lumbar disc herniation. Clin J Pain. 2001; 17(3): 215-9.

26.

Patrick

Deyo

Atlas

Singer

Chapin

Keller

. Assessing health-related quality of life in patients with sciatica. Spine (Phila PA 1976). 1995; 20(17): 1899-908.

27.

Jenkinson

Coulter

Wright

. Short form 36 (SF36) health survey questionnaire: normative data for adults of working age. BMJ. 1993; 306(6890): 1437-40.

Health-related quality of life (HRQoL) following transforaminal percutaneous endoscopic discectomy (TPED) for lumbar disc herniation: A prospective cohort study – early results

Abstract

BACKGROUND:

OBJECTIVE:

PATIENTS AND METHODS:

RESULTS:

CONCLUSIONS:

Keywords

Table 1 SF-36 scores preoperatively and at 6 weeks, 3 months, 6 months and 12 months postoperatively

2. Patients and methods

2.1 Patients’ selection

2.2 Methods

2.2.1 SF-36

2.2.2 Surgical procedure

3. Results

5. Conclusions

Conflict of interest

References

Table 1
SF-36 scores preoperatively and at 6 weeks, 3 months, 6 months and 12 months postoperatively