Surgery Versus Nonsurgical Treatment of Lumbar Spinal Stenosis

Editors' Notes Context Evidence is limited about optimal nonsurgical alternatives to surgical decompression for management of patients with symptomatic lumbar spinal stenosis (LSS). Contribution Patients with LSS who were surgical candidates and who provided consent for surgery were randomly assigned to physical therapy (PT) for 6 weeks or surgical decompression. Physical functioning, the primary outcome, was assessed after treatment and during the 2-year follow-up. Caution Half of patients in the PT group crossed over to receive surgery. Implication Patients with LSS who were offered an evidence-based PT program or surgical decompression achieved similar symptom relief and improvements in physical functioning. Lumbar spinal stenosis (LSS) is an anatomical impairment characterized by narrowing of the spinal canal or nerve root foramen (1). When a person is symptomatic, LSS causes pain; weakness in the lower back, buttocks, and thighs; and claudicating pain (1). Anatomical LSS, however, is also common in older patients who are asymptomatic (2), which underscores the importance of corroborative findings between patient history and examination (3). Even after careful examination, management decisions for persons with symptomatic LSS remain a challenge that has aptly been described as a balancing act (4), which is compounded by a lack of clear, evidence-based nonsurgical treatment options (5). Surgery remains an option for patients with persistent and severe LSS symptoms that include both back and leg pain (68). In fact, LSS is now the most often cited cause for lumbar surgery in the United States (9). Studies comparing surgical with nonsurgical treatment of LSS have been done but remain unclear about optimal nonsurgical treatment options (7, 1012). The surgical approach in these studies has been highly standardized. In contrast, the nonsurgical comparator groups commonly lack structure and detail and have inconsistent follow-through to ensure that the most basic evidence-based approaches are included, including activation, exercise, and discouragement of passive agents. In SPORT (Spine Patient Outcomes Research Trial) (6), the largest randomized, controlled trial (RCT) comparing surgical and nonsurgical treatment of LSS, the surgical group had a standard posterior decompressive laminectomy. In contrast, the nonsurgical group received usual care in which surgeons were encouraged to recommend active physical therapy (PT), education or counseling with home exercise instruction, and nonsteroidal anti-inflammatory medication as initial management strategies, but participants could receive any additional conservative treatments deemed appropriate by the surgeon. Crossover rates were 67% for the surgical group (that is, crossed over to nonsurgical intervention) and 43% in the nonsurgical group (crossed over to surgery), both of which were sufficiently high to preclude intention-to-treat (ITT) interpretations. Instead, interpretation was based on as-treated analyses for virtually all of their outcomes (11, 1316). Secondary analysis of patients in the nonsurgical group found that only 10% were provided education or counseling and 37% received PT within 6 weeks. Those receiving PT had higher self-ratings of improvement and were less likely to cross over to surgery than those who did not receive PT (17). Comparisons between surgery and standardized application of a PT program for patients with LSS have not been done. Therefore, we wanted to compare surgical decompression with a specified nonsurgical PT regimen in patients considered surgical candidates for symptomatic and degenerative LSS. Our study also evaluated sex differences in outcomes after treatment of LSS. To reduce crossover in at least 1 group of the study, we randomly assigned patients after they consented to surgery. Methods Patients were randomly assigned to 1 of 2 treatment groups: surgical decompression or PT. The primary outcome of physical function was evaluated through patient-reported outcomes. We followed patients both in the short term (first 10 weeks) and long term (at 6, 12, and 24 months). Targeted Patient Population We enrolled patients with a diagnosis of LSS identified by computed tomography using the criteria of Wiesel and colleagues (18) or magnetic resonance imaging using the criteria of Boden and colleagues (2). All patients were considered by a spine surgeon to be candidates for surgical decompression and had consented to surgery. Consent to surgery was a key inclusion criterion to ensure all participants were surgical candidates and to minimize crossover from the surgery group to the PT group. Patients also had to meet the following eligibility criteria: presence of neurogenic claudication (for example, self-reported inability to walk more than a quarter mile because of lower-extremity pain or cramping); consent to be randomly assigned to surgery or a specified PT clinic for twice-weekly exercise sessions; and no previous surgery for LSS at the level being considered for decompression. We excluded patients who were younger than 50 years, had signs of serious dementia, were diagnosed with severe vascular disease or had a recent history of myocardial infarction, had concomitant spondylolisthesis requiring spinal fusion (defined as >5 mm of slippage), had compression fractures at the level being considered for decompression, or were diagnosed with metastatic cancer. Recruitment and Consent Procedures Five neurosurgeons and 1 orthopedic spine surgeon from 2 medical centers participated in participant recruitment. All potential participants were examined initially by spine surgeons and judged to be surgical candidates. After patients consented to surgery, the surgeon introduced the study. If patients indicated an interest in the study, a study coordinator then fully explained the study and obtained consent to participate in the RCT, after which they would be randomly assigned to have surgery or attend PT. The study, conducted in western Pennsylvania, was approved by a Data and Safety Monitoring Board chartered by the National Institutes of Health and National Institute of Arthritis and Musculoskeletal and Skin Diseases and the Institutional Review Boards of University of Pittsburgh and Allegheny General Hospital (now called Allegheny Health Network). Study participants self-reported demographic and other descriptive information, including sex, age, ethnicity, past and present activity levels, present income level and employment status, and medical history. Participants also completed questionnaires about disability and other psychosocial factors. Randomization Patients were randomly assigned after the initial assessment procedures. Randomization was conducted using SAS software, version 6.2 (SAS Institute), with permuted blocks of random block sizes and stratification by sex and surgeon. Sequentially numbered and sealed envelopes with assignment allocation were prepared by the data center. A study coordinator not involved with preparing the allocation sequence opened the envelopes and assigned participants to interventions. Surgical Decompression Surgical treatment was performed similarly to that described by Rothman and Simeone (19). The protocol for surgery was identical to that used in other surgical trials for LSS (20) and included decompressive laminectomies, partial facet resection, and neuroforaminotomies performed at the levels of radiographic stenosis. No patients had spinal fusion. All surgical procedures were done by either fellowship-trained spine surgeons or surgeons with more than 20 years of experience dedicated to spine surgery. Hospital stay after surgery averaged 3 days. The postoperative course included a graduated ambulation program that began on postoperative day 1. Patients were encouraged to increase their level of walking activity as tolerated. No study funds were used to reimburse the expenses of surgical and postoperative care. PT The PT program emphasized lumbar flexion exercises, general conditioning exercises, and patient education. Each patient was evaluated by a physical therapist using an examination scheme described in our previous work (21). This examination scheme was designed to identify impairments in lower-extremity strength and flexibility that would be addressed during treatment. Treatment fidelity was assessed by the investigators. The following treatments were administered: instruction in lumbar flexion exercises, including posterior pelvic tilts and supine knee-to-chest and quadruped flexion exercises; general conditioning exercises, including stationary cycling or treadmill walking; lower-extremity strengthening exercises deemed appropriate for the patient after examination (for example, standing squats, seated knee extension, or supine straight-leg raises); lower-extremity flexibility exercises deemed appropriate for the patient on the basis of individual examination (for example, hamstring or hip flexor stretching); and patient education to avoid postures involving hyperextension of the lumbar spine. Full descriptions these treatments are available in Supplement 1. Supplement. Physical Therapy Exercise Program; Technical Description of Complier Average Causal Effects (CACE) Analyses and Inverse Probability Weighting (IPW) Analyses; and Study Protocol Physical therapy was prescribed for 6 weeks, with a frequency of 2 visits per week, and was delivered by licensed physical therapists. Patients were instructed that they could cross over to surgery at any point in the trial on the basis of a shared decision-making process with the spine surgeon. No study funds were used to reimburse PT care. Outcome and Follow-up The primary outcome for the study was the physical function score on the Short Form-36 Health Survey (SF-36) (22) at the 2-year end point. For treatment outcome scales, we administered the Oswestry Disability Index (ODI) (23) and the North American Spine Society outcome assessment instrument fo