Duration of Symptoms Resulting from Lumbar Disc Herniation:  Effect on Treatment Outcomes:  Analysis of the Spine Patient Outcomes Research Trial (SPORT)

Rihn JA, Hilibrand AS, Radcliff K, Krud M, Lurie J, Blood E, albert TJ, Weinstein JN.
J Bone Joint Surg Am. 2011;93(20):1906-1914. PubMed ID: 22012528. Available at: http://www.ncbi.nlm.nih.gov/pubmed?term=22012528

Abstract
Background:   The purpose of the present study was to determine if the duration of symptoms affects outcomes following the treatment of intervertebral lumbar disc herniation.
Methods:  An as-treated analysis was performed on patients enrolled in the Spine Patient Outcomes Research Trial (SPORT) for the treatment of intervertebral lumbar disc herniation. Randomized and observational cohorts were combined. A comparison was made between patients who had symptoms for six months or less (n = 927) and those who had symptoms for more than six months (n = 265). Primary and secondary outcomes were measured at baseline and at regular follow-up intervals up to four years. The treatment effect for each outcome measure was determined at each follow-up period for the duration of symptoms for both groups.
Results:  At all follow-up intervals, the primary outcome measures were significantly worse in patients who had had symptoms for more than six months prior to treatment, regardless of whether the treatment was operative or nonoperative. When the values at the time of the four-year follow-up were compared with the baseline values, patients in the operative treatment group who had had symptoms for six months or less had a greater increase in the bodily pain domain of the Short Form-36 (SF-36) (mean change, 48.3 compared with 41.9; p < 0.001), a greater increase in the physical function domain of the SF-36 (mean change, 47.7 compared with 41.2; p < 0.001), and a greater decrease in the Oswestry Disability Index score (mean change, -41.1 compared with -34.6; p < 0.001) as compared with those who had had symptoms for more than six months (with higher scores indicating less severe symptoms on the SF-36 and indicating more severe symptoms on the Oswestry Disability Index). When the values at the time of the four-year follow-up were compared with the baseline values, patients in the nonoperative treatment group who had symptoms for six months or less had a greater increase in the bodily pain domain of the SF-36 (mean change, 31.8 compared with 21.4; p < 0.001), a greater increase in the physical function domain of the SF-36 (mean change, 29.5 compared with 22.6; p = 0.015), and a greater decrease in the Oswestry Disability Index score (mean change, -24.9 compared with -18.5; p = 0.006) as compared with those who had symptoms for more than six months. Differences in treatment effect between the two groups related to the duration of symptoms were not significant.
Conclusions:  Increased symptom duration due to lumbar disc herniation is related to worse outcomes following both operative and nonoperative treatment. The relative increased benefit of surgery compared with nonoperative treatment was not dependent on the duration of the symptoms.
Reprinted with permission.

Commentary
Rihn et al analyzed the Spine Patient Outcomes Research Trial (SPORT) database to determine effects of treatment outcomes given the duration of symptoms resulting from lumbar disc herniation.  The SPORT study was conducted at 13 various multidisciplinary practices in the United States.  Inclusion criteria were patients over the age of 18 with radicular pain for at least six weeks despite conservative treatment, confirmatory imaging demonstrating a lumbar herniated disc at L2 or lower, and positive nerve root tension sign and/or neurologic deficit.  Cases of previous back surgery, scoliosis, malignancy, cauda equina syndrome or progressive neurologic deficit were not included in the study.  Patients in the operative treatment group received a midline posterior discectomy.  Those in the nonoperative group were treated with physical therapy, education, home exercise, medications and often, epidural steroid injections.
The data analyzed was obtained from patient questionnaires at baseline and at six weeks, three months, six months, one year, two years and four years from enrollment or surgery. The primary outcome measures were the bodily pain and physical function domains of the Short Form-36 (SF-36) and the American Academy of Orthopaedic Surgeons Musculoskeletal Outcomes Data Evaluation and Management Systems version of the Oswestry Disability Index.  Secondary measures evaluated were the patient self-reported improvement, work status and satisfaction with symptoms.
Data regarding duration of symptoms were available on 1,192 patients out of the 1,244 patients in the SPORT study.  Of these 1,192 patients, 927 patients had symptoms for six months or less and 265 had symptoms for more than six months.  Of the 927 patients who had symptoms for six months or less, 607 patients had operative treatment and 320 patients had nonoperative treatment.  In the category of patients with symptoms for more than six months, 181 patients had operative intervention versus 84 patients who had nonoperative intervention.
No differences existed between the groups of patients with six months or less, or more than six months of symptoms in terms of demographics, baseline characteristics, work status and primary outcome measures.  However, the group of patients with symptoms of more than six months had higher rates of depression, a greater proportion of preferences for surgical treatment, and higher rates of patients believing their condition was worsening.  The patients treated operatively showed no difference in the rates of blood loss, length of stay, intraoperative complications, postoperative complications and recurrence rates regardless of how long symptoms were present.  The group with symptoms longer than six months had a slightly but clinically significant increase in the operative time by 8 minutes.  In the surgical discectomy group, those with symptoms of six months or less had significantly better primary outcome measures versus those treated after six months, ie, increase in bodily pain domain of SF-36, mean change of 48.3 versus 41.9; increase in physical function domain of SF-36, mean change of 47.7 versus 41.2; greater decrease in Oswestry Disability Index score, mean change of -41.1 versus -34.6. Furthermore, the surgical treatment rendered on patient with symptoms for six months or less, demonstrated significantly better secondary outcome measures of satisfaction with symptoms, self-rated health status, working status and Sciatica Bothersomeness Scale.  The other secondary outcome measure scales of Leg Pain Bothersomeness Scale and Low Back Pain Bothersomeness Index showed improved but not clinically significant scores in the patients with symptoms for six months or less versus those with symptoms of more than six months.  Similar outcomes were also reported for those patients treated conservatively with symptoms for six months or less versus more than six months before beginning conservative treatment, ie, increase in bodily pain domain of SF-36, mean change of 31.8 vs. 21.4; increase in physical function domain of SF-36, mean change of 29.5 versus 22.6; greater decrease in Oswestry Disability Index score, mean change of -24.9 versus -18.5.  However, the patients treated surgically had better outcomes than the nonoperative group for all primary outcome measures at every time point regardless of the duration of symptoms.
Compared to the nonoperative group, patients with surgical intervention did better regardless of when the surgery was done. Thus, there was no major difference in the calculated treatment effect between patients who waited more than six months or those who didn’t, indicating that surgery provided a benefit over nonoperative treatment at all time intervals for the primary outcome measures.  However, there was less improvement in those with symptoms for more than six months.

The authors should be commended for their close analysis of the data and elucidating the clinical significance of the surgical and nonsurgical treatment rendered on patients with symptoms of six months or less versus more than six months.  However, the conservative treatment regimens of this study were not well described.  The “minimum nonsurgical treatment” as defined by this study consisted of active physical therapy, education and/or counseling with home exercises and a nonsteroidal anti-inflammatory medication treatment.  However, the use of epidural injections was not standardized.  Fluoroscopically guided transforminal selective epidural steroid injections have a very definitive role in the treatment of lumbar disc herniations without neurologic deficit.1,2 Furthermore, the form of physical therapy performed is very relevant.  Performing the correct modalities does affect the nonoperative treatment success.3  Further studies should explore the clinical relevance of an appropriate and aggressive conservative treatment protocol and the duration of patients’ symptoms.
This paper does an excellent job helping us better educate our patients on the effectiveness of different treatment options given the duration of symptoms.  The sooner treatment is rendered, the better the results, whether nonoperative or  surgical. Thus, the spine surgeon needs to educate the patient given the data of this study and help him or her make the best decision based on their circumstances.

References
1.    Benny B, Azari P. The efficacy of lumbosacral transforaminal epidural steroid injections: a comprehensive literature review. J Back Musculoskelet Rehabil. 2011;24 (2): 67-76.
2.    Roberts ST, et al. Efficacy of lumbosacral transforaminal epidural injections: a systematic review. Physical Medicine and Rehabilitation (PM R). July; 1 (7): 657-68.
3.    Albert HB, Manniche C. The efficacy of systematic active conservative treatment for patients with severe sciatica: a single-blind, randomized, clinical, controlled trial. Spine. 2012, April, 1 37 (7): 531-42.

Author Disclosure
A Moshirfar: nothing to disclose