Association of Neuromuscular Attributes With Performance-Based Mobility Among Community-Dwelling Older Adults With Symptomatic Lumbar Spinal Stenosis

Physical Therapy and Health Care Utilization for Older Adults With Lumbar Spinal Stenosis

BACKGROUND AND PURPOSE

Lumbar spinal stenosis (LSS) is associated with high health care utilization for older adults. Physical therapy (PT) offers low medical risk and reduced cost burden with functional outcomes that appear to be equivalent to higher risk interventions such as surgery. However, it is unknown whether receipt of PT following incident LSS diagnosis is associated with reduced health care utilization. The objectives of this study were to: (1) compare health characteristics for Medicare beneficiaries who received outpatient PT within 30 days of incident LSS diagnosis to those who did not; (2) compare the 1-year utilization rates for specific health care services for these 2 groups; and (3) quantify the likelihood of progression to specific health services based on the receipt of PT.

METHODS

This was a retrospective cohort study using nationally representative claims data for Medicare Part B beneficiaries between 2007 and 2010. Lumbar spinal stenosis was determined using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Beneficiaries 65 years and older were classified into 2 groups (PT and no PT) based on receipt of PT within 30 days of initial diagnosis. Baseline characteristics were identified at incident diagnosis. Hazard ratios (HRs) were estimated for the risk of receiving health services outcomes including spinal surgery, spinal injections, chiropractic care, advanced imaging, spinal radiographs, opioid medication, nonopioid analgesics, and hospitalizations beginning on day 31 up to 1 year following incident LSS diagnosis.

RESULTS AND DISCUSSION

Among 60 646 Medicare beneficiaries with incident LSS who met the inclusion criteria, 1124 were classified in the PT group and 59 522 in the no PT group. Compared with the PT group, beneficiaries in the no PT group had a greater risk of having hospitalizations (HR = 1.40), opioid medications (HR = 1.29), spinal surgery (HR = 1.29), and spinal radiographs (HR = 1.19) within 1 year.

CONCLUSIONS

Fewer than 2% of Medicare beneficiaries received PT within 30 days of initial LSS diagnosis. Receipt of PT was associated with less utilization of higher risk and costly health services for 1 year. These results may inform practitioners when making early decisions about rehabilitative care for older adults with LSS.

Physical and Psychological Factors Associated With Walking Capacity in Patients With Lumbar Spinal Stenosis With Neurogenic Claudication: A Systematic Scoping Review

Objective: The purpose of this study was to evaluate the current state of scientific knowledge regarding physical and psychological factors associated with walking capacity in patients with lumbar spinal stenosis (LSS) with neurogenic claudication. Design: Systematic scoping review. Literature Search: We searched CINAHL (Cumulative Index to Nursing and Allied Health Literature), MEDLINE, Cochrane, PsycINFO, and SPORTDiscus databases. Study Selection Criteria: Cohorts and cross-sectional studies reporting on associations between physical or psychological factors and impaired walking capacity in patients with symptomatic LSS were included. Data Synthesis: Data were synthetized to identify associations between physical or psychological factors and either walking capacity, gait pattern characteristics, or functional tasks. Results: Twenty-four studies were included. Walking capacity was significantly correlated with several pain outcomes, disability, estimated walking distance, and cross-sectional area of the lumbar spine. Gait pattern characteristics such as speed and stride were strongly and positively correlated with disability outcomes. Functional tasks were significantly correlated with lower back and upper limb disability, lower limb endurance strength, ranges of motion, and speed. Associations with psychological factors were mostly conflicting except for the Rasch-based Depression Screener and the Pain Anxiety Symptom Scale (PASS-20) questionnaire that were associated with a decreased performance in functional tasks. Conclusion: Physical and psychological factors that are associated with walking capacity in patients with symptomatic LSS were identified. However, many associations reported between physical or psychological factors and walking capacity were conflicting, even more so when correlated with walking capacity specifically.

Gait analysis in the elderly patients with lumbar spinal stenosis

PURPOSE

This study aims to analyze the gait characteristics of the elderly patients with lumbar spinal stenosis by an intelligent device for energy expenditure and activity (IDEEA) to assist clinical work.

METHODS

A total of 98 subjects were included in this study from January 2017 to December 2018. A total of 49 elderly outpatients with symptomatic lumbar spinal stenosis in unilateral lower extremity were included as the experimental group, and another 49 healthy subjects matched with gender, age, and body mass index (BMI) were analyzed as the control group. The gait data of the subjects (including single support, double support, SLS/DLS, swing duration, step duration, cycle duration, pulling accel, swing power, ground impact, foot fall, foot off, push off, speed, cadence, step length, and stride length) were collected to compare between the experience group and control group, the affected leg and the healthy leg in experimental group.

RESULTS

The results of this study presented that small intermittent claudication occurred in all patients. The time of single support was significantly increased (p < 0.05). Double support, step duration, and pulling accel were increased (p < 0.05), and the Push off, speed, step length, and Stride length were decreased (p < 0.05) in the experimental group compared with the control group.

CONCLUSION

Small intermittent claudication was the basic gait composition of the elderly patients with lumbar spinal stenosis that can reflect the abnormal gait characteristics by IDEEA.

Randomized double blind clinical trial of ABM/P-15 versus allograft in noninstrumented lumbar fusion surgery

BACKGROUND CONTEXT

Due to poor bone stock in the elderly, a noninstrumented fusion is commonly performed in Scandinavia when instability is present. Allograft bone is often used as graft extender with consequent low fusion rates. The use of 15 amino acid residue (ABM/P-15) has shown superior fusion rates in dental and cervical spinal surgery but no clinical studies have been conducted in noninstrumented lumbar fusion surgery.

PURPOSE

To evaluate patient reported outcomes (PROs) and the intertransverse fusion rate in noninstrumented posterolateral fusion with either ABM/P-15 or allograft.

STUDY DESIGN

Double-blind randomized clinical trial.

PATIENT SAMPLE

Patients 60 years or older with degenerative spondylolisthesis undergoing decompression and noninstrumented posterolateral fusion.

OUTCOME MEASURES

Visual analog scales for back and leg pain, Oswestry Disability Index and EuroQoL-5D.

METHODS

One hundred one patients were enrolled in the study and randomized 1:1 to either ABM/P-15 (mixed 50/50, 5cc/level) or allograft bone (30 g/level), both mixed with local bone graft. PROs were collected at baseline and at 12 and 24 months after surgery. The patients underwent 1-year postoperative fine cut computed tomography-scans (0.9 mm) with reconstructions, independently evaluated by three reviewers. Fusion status was concluded by consensus of two of the three as "fusion" or "no fusion."

RESULTS

There were 49 patients available for analysis in both cohorts. The two groups were similar in terms of sex distribution, age, and number of levels fused. The fusion rate was significantly higher in the ABM/P-15 group with 50% fused compared with 20% in the allograft group. PROs at baseline and at all follow-up time points were similar between the two groups.

CONCLUSIONS

Patients undergoing noninstrumented posterolateral fusion augmented with ABM/P-15 had a statistically significantly higher fusion rate compared with allograft when evaluated with postoperative fine cut computed tomography-scans (0.9 mm) with reconstructions. However, this did not translate to better clinical outcomes.

Multifidus muscle fatty infiltration as an index of dysfunction in patients with single-segment degenerative lumbar spinal stenosis: A case-control study based on propensity score matching

The multifidus muscle morphology and its relation to the function of patients with degenerative lumbar spinal stenosis (DLSS) remains unclear. This study aimed to investigate the multifidus muscle morphology in patients with DLSS and to determine its relations to the patients function. Sixty-two patients with single-segment DLSS at L4-5 and sixty control patients with non-spinal-derived low back pain were retrospectively enrolled and further matched based on propensity scores. The Oswestry Disability Index (ODI) and bodily pain using the Short-Form Health Survey were evaluated. The cross-sectional area (CSA), CSA of fatty free (CSAF), and fatty infiltration rate [FIR; i.e., (1- CSAF/CSA) × 100%] of the multifidus muscle were measured on magnetic resonance images using ImageJ software. Adjustment for confounders was performed using generalized linear models. The FIR at L5-S1 in controls was statistically significant but slightly less than the DLSS group. The between-groups difference was 5% (p < 0.001), and 2.8% (p = 0.036) in the complete and matching cohorts, respectively, after adjustment. Statistically significant differences were not observed in other multifidus muscle parameters between the groups. FIR > 20% at L5-S1 was independently associated with ODI ≥ 41 in patients with DLSS [Retaining demography as control block or not, Odds ratio (OR) = 8.4, p = 0.023; OR = 12.3, p = 0.030]. The multifidus muscle at L5-S1 demonstrated slightly greater fatty infiltration in patients with L4-5 single-segment DLSS than controls. Significant fatty infiltration in the multifidus muscle at L5-S1 may be correlated with poor function in patients with L4-5 single-segment DLSS.

Age- and sex-specific effects in paravertebral surface electromyographic back extensor muscle fatigue in chronic low back pain

The impact of aging on the back muscles is not well understood, yet may hold clues to both normal aging and chronic low back pain (cLBP). This study sought to investigate whether the median frequency (MF) surface electromyographic (SEMG) back muscle fatigue method—a proxy for glycolytic muscle metabolism—would be able to detect age- and sex-specific differences in neuromuscular and muscle metabolic functions in individuals with cLBP in a reliable way, and whether it would be as sensitive as when used on healthy individuals. With participants seated on a dynamometer (20° trunk anteflexion), paraspinal SEMG activity was recorded bilaterally from the multifidus (L5), longissimus (L2), and iliolumbalis (L1) muscles during isometric, sustained back extensions loaded at 80% of maximum from 117 younger (58 females) and 112 older (56 female) cLBP individuals. Tests were repeated after 1–2 days and 6 weeks. Median frequency, the SEMG variable indicating neuromuscular fatigue, was analyzed. Maximum back extensor strength was comparable between younger and older participants. Significantly less MF-SEMG back muscle fatigue was observed in older as compared to younger, and in older female as compared to older male cLBP individuals. Relative reliability was excellent, but absolute reliability appeared large for this SEMG-fatigue measure. Findings suggest that cLBP likely does not mask the age-specific diagnostic potential of the MF-SEMG back extensor fatigue method. Thus, this method possesses a great potential to be further developed into a valuable biomarker capable of detecting back muscle function at risk of sarcopenia at very early stages.

Which Neuromuscular Attributes Are Associated With Changes in Mobility Among Community-Dwelling Older Adults With Symptomatic Lumbar Spinal Stenosis?

OBJECTIVES

To identify neuromuscular attributes associated with mobility and changes in mobility over 2 years of follow-up among patients with and without symptomatic lumbar spinal stenosis (SLSS).

DESIGN

Secondary analysis of a longitudinal cohort study.

SETTING

Outpatient rehabilitation center.

PARTICIPANTS

Community-dwelling older adults ≥65 years with self-reported mobility limitations (N=430). SLSS was determined using self-reported symptoms of neurogenic claudication and imaging-detected lumbar spinal stenosis.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

Basic and advanced mobility as measured by the Late-Life Function and Disability Instrument (LLFDI).

RESULTS

Among 430 community-dwelling older adults, 54 (13%) patients met criteria for SLSS, while 246 (57%) did not. On average LLFDI basic and advanced mobility scores decreased significantly from baseline through year 2 for participants with SLSS (basic: P=.04, 95% CI 0.18, 5.21; advanced P=.03, 95% CI 0.39, 7.84). Trunk extensor muscle endurance (trunk endurance) and leg strength were associated with baseline basic mobility (R2=0.27, P<.001) while leg strength and knee flexion range of motion (ROM) were associated with baseline advanced mobility among participants with SLSS (R2=0.47, P<.001). Among participants without SLSS trunk endurance, leg strength and ankle ROM were associated with baseline basic mobility (R2=0.38, P<.001), while trunk endurance, leg strength, leg strength asymmetry, and knee flexion ROM were associated with advanced mobility (R2=0.20, P<.001). Trunk endurance and leg strength were associated with change in basic mobility (R2=0.29, P<.001), while trunk endurance and knee flexion ROM were associated with change in advanced mobility (R2=0.42, P<.001) among participants with SLSS. Among participants without SLSS trunk endurance, leg strength, knee flexion ROM, and ankle ROM were associated with change in basic mobility (R2=0.22, P<.001), while trunk endurance, leg strength, and knee flexion ROM were associated with change in advanced mobility (R2=0.36, P<.001).

CONCLUSIONS

Patients with SLSS experience greater impairment in the neuromuscular attributes: trunk endurance, leg strength, leg strength asymmetry, knee flexion and extension ROM, and ankle ROM compared to patients without SLSS. Differences exist in the neuromuscular attributes associated with mobility at baseline and decline in mobility over 2 years of follow-up for patients with and without SLSS. These findings may help guide rehabilitative care approaches for patients with SLSS.

Inertial Sensor-Based Gait and Attractor Analysis as Clinical Measurement Tool: Functionality and Sensitivity in Healthy Subjects and Patients With Symptomatic Lumbar Spinal Stenosis

Objective: To determine if the attractor for acceleration gait data is similar among healthy persons defining a reference attractor; if exercise-induced changes in the attractor in patients with symptomatic lumbar spinal stenosis (sLSS) are greater than in healthy persons; and if the exercise-induced changes in the attractor are affected by surgical treatment.

Methods: Twenty-four healthy subjects and 19 patients with sLSS completed a 6-min walk test (6MWT) on a 30-m walkway. Gait data were collected using inertial sensors (RehaGait^®;) capturing 3-dimensional foot accelerations. Attractor analysis was used to quantify changes in low-pass filtered acceleration pattern (δM) and variability (δD) and their combination as attractor-based index (δF = δM^* δD) between the first and last 30 m of walking. These parameters were compared within healthy persons and patients with sLSS (preoperatively and 10 weeks and 12 months postoperatively) and between healthy persons and patients with sLSS. The variability in the attractor pattern among healthy persons was assessed as the standard deviation of the individual attractors.

Results: The attractor pattern differed greatly among healthy persons. The variability in the attractor between subjects was about three times higher than the variability around the attractor within subject. The change in gait pattern and variability during the 6MWT did not differ significantly in patients with sLSS between baseline and follow-up but differed significantly compared to healthy persons.

Discussion: The attractor for acceleration data varied largely among healthy subjects, and hence a reference attractor could not be generated. Moreover, the change in the attractor and its variability during the 6MWT differed between patients and elderly healthy persons but not between repeated assessments. Hence, the attractor based on low-pass filtered signals as used in this study may reflect pathology specific differences in gait characteristics but does not appear to be sufficiently sensitive to serve as outcome parameter of decompression surgery in patients with sLSS.