<LEAP> highlights the findings and application of Cochrane reviews and other evidence pertinent to the practice of physical therapy. The Cochrane Library is a respected source of reliable evidence related to health care. Cochrane systematic reviews explore the evidence for and against the effectiveness and appropriateness of interventions—medications, surgery, education, nutrition, exercise—and the evidence for and against the use of diagnostic tests for specific conditions. Cochrane reviews are designed to facilitate the decisions of clinicians, patients, and others in health care by providing a careful review and interpretation of research studies published in the scientific literature.1 Each article in this PTJ series summarizes a Cochrane review or other scientific evidence on a single topic and presents clinical scenarios based on real patients or programs to illustrate how the results of the review can be used to directly inform clinical decisions. This article focuses on the case of a 33-year-old man who was seen for physical therapy 6 weeks after lumbar microdiskectomy. Can an active rehabilitation program increase function and decrease pain?
Low back pain (LBP) may be associated with lumbar intervertebral disk herniation. A subset of patients with diskogenic LBP may have radicular symptoms that include buttock and leg pain and dermatomal or myotomal deficits. Other signs of neurological compromise associated with lumbar disk herniation are bowel and bladder dysfunction and saddle paresthesia. Lumbar diskectomy may be indicated when diagnostic imaging reveals disk herniation, which correlates with radicular and or neurological symptoms.2,3 For patients with pain and functional limitations persisting postsurgery, physical therapy may be a viable postoperative treatment option.3,4 The usual care provided by physical therapists may include patient education, ice, heat, electrotherapy, stretching, trunk and lower-extremity muscle conditioning exercise, and manual therapy.5 Active rehabilitation programs are heterogeneous in start time, level of supervision, exercise selection, dosage, and duration. There are unanswered questions as to the most effective characteristics, the risk of recurrent herniation or instability, and the added value of active rehabilitation programs.6–8
Ostelo et al9 addressed these questions by performing a Cochrane systematic review to determine whether active rehabilitation after lumbar disk surgery is more effective than no treatment and to describe which type of active rehabilitation is most effective. They included randomized controlled trials published up to May 2007. The study participants were 18 to 65 years old and had undergone first-time lumbar disk surgery. These trials investigated 1 or more types of active rehabilitation aiming at functional restoration (improvement in functional status and return to work). Ostelo et al excluded trials that investigated treatments solely aimed at pain relief via medication or improvements in strength or flexibility. Trials were included if they assessed at least 1 of 4 primary outcomes: pain, a global measure of improvement, back pain–specific functional status, and return to work. The review clustered treatments according to the start of treatment (immediately following surgery, starting 4–6 weeks following surgery, and starting more than 12 months following surgery). For each cluster, the review considered the following comparisons: (1) active rehabilitation versus no treatment, placebo, or waiting list control; (2) active rehabilitation versus other kind of active rehabilitation; and (3) a specific intervention in addition to active rehabilitation versus active rehabilitation alone.
The review authors presented the overall quality of the evidence using the GRADE approach.10 Using this approach, the assessment of quality is based on 5 domains: study design, consistency, directness, precision, and lack of publication bias. Quality ranges from high, moderate, and low to no evidence. A rating will drop by 1 level for each domain in which criteria are not met.11 The Table outlines the results of the review by Ostelo and colleagues.9
Key Results From the 2008 Cochrane Review9,a
Take-Home Message
Ostelo and colleagues9 identified 14 trials with 1,927 participants. Studies were clustered by start time of intervention for analysis: immediately after surgery (2 studies), 4 to 6 weeks after surgery (10 studies), and starting after 12 months following surgery (2 studies). Seven of the 14 studies were considered to be at low risk of bias.
Of the 2 trials starting immediately after surgery, neither trial compared active rehabilitation with either placebo or no treatment. Therefore, it is not known whether commencing active rehabilitation immediately after surgery is effective or safe. The first trial (N=60) at high risk of bias showed no differences in outcomes between a more-intensive exercise program and a less-intensive exercise program. A second trial (N=59) at low risk of bias showed that neural mobilization provided no added benefit to standard postoperative care.
Pooling of results was feasible for 8 of the 10 trials in which intervention began 4 to 6 weeks postsurgery. Weighted mean differences (WMDs) were reported when outcome measures, study population, and types of treatment were homogeneous. When this level of comparison was not possible, the review authors reported standardized mean differences (SMDs). Three comparisons were made: exercise programs versus no treatment, high-intensity versus low-intensity exercise programs, and supervised versus home exercise programs.
Exercise Versus No Intervention
Based on 3 small trials (1 at low risk of bias and 2 at high risk of bias) (N=122), there was low-quality evidence that exercise programs were more effective in the short term than no treatment for pain (WMD=−11.13, 95% confidence interval [CI]=−18.44 to −3.82, on a 0–100 visual analog scale [VAS]) and moderate-quality evidence that they were more effective with respect to functional status (WMD=−6.50, 95% CI=−9.26 to −3.74, on the 0–50 Modified Oswestry Disability Index). None of the trials reported that these active programs increased the re-operation rate.
High-Intensity Versus Low-Intensity Exercise
Based on 3 trials (2 at low risk of bias and 1 at high risk of bias) (N=201), there was low-quality evidence that high-intensity exercise programs might be slightly more effective than low-intensity exercise programs for pain in the short term (WMD=−10.67, 95% CI=−17.04 to −4.30, on a 0–100 VAS) and moderate-quality evidence they also may provide greater improvement in functional status (SMD=−0.77, 95% CI=−1.17 to −0.36). However, long-term results were conflicting. Complications and re-operation rates did not differ among groups.
Supervised Versus Home Exercise
Based on 3 trials (all at high risk of bias) (N=142), there was low-quality evidence of no significant differences between supervised or home-based exercise programs with respect to function (SMD=−1.17, 95% CI=−2.63 to 0.28) and pain (SMD=1.12, 95% CI=−2.77 to 0.53). However, neither the programs nor the participants' adherence was well described.
Two trials assessed treatments that started more than 12 months following surgery. One trial, with a low risk of bias (N=62), provided low-quality evidence that adding hyperextension exercises to an intensive exercise program was of no added benefit in terms of functional status. The second trial, with a high risk of bias (N=250), provided low-quality evidence that low-tech exercise (repeated extension and spinal stabilization exercise) or high-tech exercise (isotonic and isokinetic trunk muscle training) might be more effective in improving low back functional status compared with physical agents, joint manipulation, or no treatment.
Case #14: Exercise Following Lumbar Diskectomy
Can an exercise program help this patient?
Mr Neff is a previously healthy and physically active 33-year-old man who was seen for physical therapy 6 weeks following an L5–S1 lumbar microdiskectomy. His neurosurgeon had referred him for physical therapy for strength training, core conditioning, activities of daily living training, and posture/body mechanics education to address residual symptoms and to prevent reinjury. He had resumed working half time as a rental property manager but had not yet returned to his other job as a TV commercial actor or to his recreational activities (surfing, mountain biking, Ashtanga yoga, and soccer).
At the start of physical therapy, Mr Neff's exercise was limited to walking 30 minutes daily. Pain levels ranged from 0 to 60 on a 0 to 100 VAS, specifically 30/100 calf pain with standing and walking more than 5 minutes, 60/100 calf pain and LBP with sitting longer than 30 minutes, and 60/100 back pain with bending forward or twisting. The Modified Oswestry Disability Index score was 14 (0- to 50-point scale), indicating moderate disability.12 Based on the modified Sorenson test, Mr Neff achieved a horizontal trunk hold for 35 seconds limited by back muscle fatigue, implying impaired back muscle function.13 A single-stage, 4-minute treadmill test was performed to estimate aerobic capacity.14 Mr Neff was classified as having fair aerobic fitness according to the norms for his age group, ranking in the 45th percentile.15
How did the clinician apply the results of the Cochrane systematic review to Mr Neff?
Using a PICO (Patient, Intervention, Comparison, Outcome) format, the clinician formulated the question: In a 33-year-old man following first-time lumbar microdiskectomy with residual LBP and lower-extremity symptoms, will a high-intensity exercise program, initiated 4 to 6 weeks postoperatively, increase function and reduce pain?
Mr Neff's age, symptoms, and diagnosis were well matched to those of the patients included in this review, and the results of the review were deemed applicable to this case. The physical therapist, therefore, developed an individualized high-intensity exercise program for Mr Neff. The program began 6 weeks postsurgery based on low- to moderate-quality evidence.9 The following 4 variables were considered in the program design: level of supervision, ingredients, intensity, and dosage.
Mr Neff's program was both supervised and home based. This approach was motivated by his available insurance, which covered 24 physical therapy visits per year, and by low-quality evidence suggesting no difference between supervised and home exercise programs. Exercises were performed 3 times per week for 12 weeks. The first 2 weeks included 2 supervised sessions and 1 home session per week to initiate the program and complete exercise technique training. Weeks 3 to 8 included 1 supervised session and 2 sessions of home exercise per week. Supervision continued once every other week for weeks 9 to 12. At week 12, the patient was given instructions for a continuation and self-progression of the exercises. There were a total of 12 supervised visits.
The ingredients of the program were exercises targeting the abdominals, lower back, and lower-extremity musculature. This exercise selection paralleled that of 8 studies included in the review. Abdominal conditioning took place in supine, quadruped, and side plank positions, with progression based on varied lever arms to the muscles of the trunk and extremities. Isometric back muscle conditioning included prone trunk holds over a Swiss ball and the use of a modified roman chair with variable trunk lever arms.13 Lower-extremity exercise included squats of varied depth, split squats, and multidirectional lunges.
The inclusion of cardiovascular exercise training was limited to 1 of the 14 studies in the review. Cardiovascular training was deemed a critical ingredient for Mr Neff, given the fact that he had experienced 16 weeks of detraining prior to postoperative rehabilitation and his participation goals to return to hiking and soccer.16 He was prescribed a home walking program beginning at 60% to 70% of his estimated maximum oxygen consumption metabolic equivalents and monitored with heart rate at 60% to 70% of heart rate reserve.15 Hiking and a combination of walking and running were added during the 12-week program.
For the muscle conditioning exercises, Mr Neff trained with high repetitions (≥12) and multiple sets for dynamic exercises or with repeated sustained holds for the isometric exercise. This dosage was consistent among exercise programs included in the review, which described the exercise prescription parameters. Resistance to each exercise was provided by body weight and external loading. The patient was instructed to exercise at a perceived exertion described as moderate to hard, provided technique was optimal and symptoms did not increase.13 The dosing of Mr Neff's aerobic exercise program was based on submaximal cardiovascular fitness test results.
There is one caveat relative to the intensity and dosage of the training in Mr Neff's program. When applying basic exercise prescription principles, it appears that exercise programs after lumbar diskectomy referred to in the systematic review targeted muscular endurance adaptations via high-volume training and did not represent high-intensity training.17 The muscular demand of commonly selected exercises in the high-intensity programs described in this review typically elicit <70% of maximal voluntary contraction for target muscles.18 Resistance training models refer to this level of muscular demand as low intensity. Individuals training at a low intensity require high repetitions (≥12), multiple sets, and prolonged hold times for isometric exercise to elicit training adaptations. The product of low intensity, high repetitions, and multiple sets is referred to as high-volume training. The resultant primary physiological muscular adaption is muscular endurance. This program is in contrast to low-volume training, the product of high intensity (≥85% of maximum voluntary contraction), low repetitions, and multiple sets. The resultant primary physiological muscular adaptation is muscular strength.17
How well do the outcomes of the intervention provided to the patient match those suggested by the systematic review?
Mr Neff's participation in the redefined “high-intensity” exercise program after first-time lumbar diskectomy resulted in outcomes similar to those reported in the systematic review by Ostelo et al.9 Function and participation levels increased, pain levels decreased, and there were no complications. Postintervention pain levels ranged from 0 to 20/100. Standing and walking were pain-free, and calf and back pain increased to 20/100 after 45 minutes of sitting. This decrease in pain exceeds the minimal clinically important change of 20/100 points on the VAS.19 The difference in Modified Oswestry Disability Index scores from before intervention to following intervention also surpassed the standard for minimal clinically important change of 10/50 points and decreased to 4/50 points.20
Mr Neff's activity and recreational participation level increased postintervention to include kicking a soccer ball with his son, 45 minutes of mountain biking once per week, ocean swimming once per week with paddling on a surfboard, and hiking 60 minutes once per week. Mr Neff reported working at full premorbid capacity as a rental property manager and had resumed participating in television commercial auditions. His schedule had not yet allowed him to return to pickup soccer games and yoga.
Can you apply the results of the systematic review to your patients?
The results of the systematic review can be applied to adults (mean or median age=30–40 years) who have had a first-time lumbar diskectomy. The review indicated that exercise programs initiated 4 to 6 weeks after surgery may decrease pain and disability compared with no rehabilitation program. It also suggests that, compared with low-intensity programs, higher-intensity exercise programs might lead to faster decreases in pain and disability and that there are no significant differences between supervised and home-based exercise programs. Active rehabilitation was not found to increase re-operation rates.
However, the review authors also highlighted the fact that the included studies were heterogeneous with regard to start time, duration, and intensity of the interventions. Furthermore, clinical heterogeneity limited their ability to pool data. Therefore, the results need to be interpreted with caution. It is still not clear whether all people who have had surgery require an active rehabilitation program or whether this type of program should be reserved for people who still have symptoms 4 to 6 weeks postsurgery. Further work to define the optimal rehabilitation program also is needed.
A more recent systematic review by Rushton et al21 that included trials published in English up to December 2009 investigating outpatient physical therapy treatment following first-time lumbar diskectomy was published in 2011. It included 16 trials, only 10 of which were included in the Cochrane review by Ostelo and colleagues.9 Rushton and colleagues concluded that the evidence for outpatient physical therapy after first-time lumbar diskectomy was inconclusive.
What can be advised based on the results of this systematic review?
The results of this review indicate that individuals can safely engage in high- or low-intensity supervised or home-based exercises initiated at 4 to 6 weeks following first-time lumbar diskectomy. There may be small benefits in terms of reduced pain, improved function, and increased activity tolerance over the short term without increased risk of complications.9,21 However, further research is needed to determine the ideal time to start an active rehabilitation program, the exact content and duration of the program, and whether active rehabilitation is useful for everyone or only selected subgroups who have persisting symptoms.
- Received March 4, 2012.
- Accepted January 10, 2013.
- © 2013 American Physical Therapy Association
References
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