Natalie A. Glass

Quadriceps weakness predicts risk for knee joint space narrowing in women in the MOST cohort

OBJECTIVE Quadriceps weakness has been reported with incident but not progressive knee osteoarthritis (OA) in longitudinal studies. This study examined the relationship between quadriceps strength and worsening of knee joint space narrowing (JSN) over 30 months. METHODS Longitudinal, observational study of adults aged 50-79 years with OARSI JSN score <3 at baseline. Baseline measures included bilateral weight-bearing fixed flexion radiographs, isokinetic concentric quadriceps and hamstring strength, height and weight, and physical activity. Hamstring:quadriceps (H:Q) strength ratios also were evaluated. Worsening was defined as an increase in JSN score in the tibiofemoral and/or patellofemoral compartments on 30-month radiographs or total knee replacement. Knee-based analyses used generalized estimating equations, stratified by sex, to assess relationships between strength and knee JSN while controlling for covariance between knees within subjects as well as age, body mass index (BMI), history of knee injury and/or surgery, physical activity level and alignment. RESULTS 3856 knees (2254 females and 1602 males) with JSN score <3 at baseline and no missing follow-up data were included. Mean+/-SD age was 62.2+/-7.7 in women and 61.6+/-8.1 in men. Women in the lowest tertile of quadriceps strength had an increased risk of whole knee JSN (OR=1.66, 95% CI=1.26, 2.19) and tibiofemoral JSN (OR=1.69, 95% CI=1.26, 2.28). However, no associations were found between strength and JSN in men or H:Q<0.6 and JSN in men or women. CONCLUSIONS In women but not in men, quadriceps weakness was associated with increased risk for tibiofemoral and whole knee JSN.

Effect of quadriceps strength and proprioception on risk for knee osteoarthritis.

PURPOSE Impaired quadriceps strength and joint position sense (JPS) have been linked with knee osteoarthritis (OA) cross-sectionally. Although neither has been independently associated with incident radiographic OA, their combination may mediate risk. The purpose of this study was to determine whether better sensorimotor function protects against the development of incident radiographic or symptomatic knee OA. METHODS The Multicenter Osteoarthritis study is a longitudinal study of adults aged 50–79 yr at high risk for knee OA. Participants underwent bilateral, weight-bearing, fixed-flexion radiographs, JPS acuity tests, and isokinetic quadriceps strength tests. The relationships between combinations of the tertiles of sex-specific baseline peak strength and mean JPS and development of incident radiographic (Kellgren–Lawrence (KL) grade Q2) or symptomatic knee OA (KL grade Q2 and frequent knee pain or stiffness) at a 30-month follow-up were evaluated. Secondary analyses defined JPS as the variance during the 10 JPS trials and also assessed the interaction of strength and JPS in predicting each outcome. RESULTS The study of incident radiographic knee OA included 1390 participants (age = 61.2 ± 7 .9 yr and body mass index = 29.4 ± 5.1 kg·m−²), and the study of incident symptomatic knee OA included 1829 participants (age = 62.2 ± 8.0 yr and body mass index = 30.0 ± 5.4 kg·m−²). Greater strength at baseline protected against incident symptomatic but not radiographic knee OA regardless of JPS tertile. There was no significant relationship between the strength–JPS interaction and the development of radiographic or symptomatic knee OA. CONCLUSIONS The finding that quadriceps strength protected against incident symptomatic but not radiographic knee OA regardless of JPS tertile suggests that strength may be more important than JPS in mediating risk for knee OA.

Is quadriceps muscle weakness a risk factor for incident or progressive knee osteoarthritis

Abstract The role of the quadriceps muscle in mediating risk for knee osteoarthritis (OA) is a common subject of investigation. The quadriceps muscle is a principal contributor to knee joint stability and provides shock absorption for the knee during ambulation. Clinically, weakness of the quadriceps muscle is consistently found in patients with knee OA. Research has shown that higher quadriceps muscle strength is associated with a reduced risk for incident symptomatic knee OA. However, there is limited evidence to suggest that quadriceps muscle plays a significant role in the incidence of radiographic knee OA. In addition, greater quadriceps muscle strength is associated with a lower risk for progression of tibiofemoral joint space narrowing and cartilage loss in women. This article summarizes knowledge of the relationship between quadriceps muscle strength and risk for knee OA.

The Multicenter Osteoarthritis Study: Opportunities for Rehabilitation Research

The Multicenter Osteoarthritis Study (MOST) is a longitudinal observational study of the effects of biomechanical, bone and joint structural, and nutritional factors on the incidence and progression of knee symptoms and radiographic and symptomatic knee osteoarthritis (OA). It is the first large-scale epidemiologic study to focus on symptomatic knee OA in a community-based sample of adultswith or at high risk for knee OA, based on thepresence of knee symptoms, history of knee injury or surgery or being overweight. Beginning in 2003, 3026 individuals (60.1% women) age 50-79 years were enrolled. Examinations at baseline, and 15, 30, 60, 72 and 84 months later included assessment of risk factors, disease characteristics, body functions and structure, and measures of physical activity and participation. The wealth of data from this longitudinal cohort of community-dwelling older adults affords valuable opportunities for rehabilitation researchers.

Pregnancy Leads to Lasting Changes in Foot Structure

ObjectiveWomen are disproportionately affected by musculoskeletal disorders. Parous women seem to be at a particularly elevated risk for structural and functional changes in the lower limbs. The combination of increased weight on the joints with potentially greater laxity during pregnancy could lead to permanent structural changes in the feet. Although arches may become lax during pregnancy, it is unknown whether the changes persist. The objective of this study was to determine whether arch height loss persists postpartum. DesignForty-nine women completed this longitudinal study. Static and dynamic arch measurements were collected in the first trimester and at 19 wks postpartum. Linear mixed models were used to determine whether outcome measures significantly changed overall or by parity. ResultsArch height and rigidity indices significantly decreased, with concomitant increases in foot length and arch drop. The first pregnancy accounted for the reduction in arch rigidity and the increases in foot length and arch drop. No changes were detected in the center of pressure excursion index. ConclusionsPregnancy seems to be associated with a permanent loss of arch height, and the first pregnancy may be the most significant. These changes in the feet could contribute to the increased risk for musculoskeletal disorders in women. Further research should assess the efficacy of rehabilitative interventions for prevention of pregnancy-related arch drop.

Opioid Use After Total Knee Arthroplasty: Trends and Risk Factors for Prolonged Use

BACKGROUND The United States is in the midst of an opioid epidemic. Little is known about perioperative opioid use for total knee arthroplasty (TKA). The purpose of this study was to identify rates of preoperative opioid use, evaluate postoperative trends and identify risk factors for prolonged use after TKA. METHODS Patients who underwent primary TKA from 2007-2014 were identified within the Humana database. Postoperative opioid use was measured by monthly prescription refill rates. A preoperative opioid user (OU) was defined by history of opioid prescription within 3 months prior to TKA and a non-opioid user (NOU) was defined by no history of prior opioid use. Rates of opioid use were trended monthly for one year postoperatively for all cohorts. RESULTS 73,959 TKA patients were analyzed and 23,532 patients (31.2%) were OU. OU increased from 30.1% in 2007 to 39.3% in 2014 (P < .001). Preoperative opioid use was the strongest predictor for prolonged opioid use following TKA, with OU filling significantly more opioid prescriptions than NOU at every time point analyzed. Younger age, female sex and other intrinsic factors were found to significantly increase the rate of opioid refilling following TKA throughout the postoperative year. CONCLUSION Approximately one-third of TKA patients use opioids within 3 months prior to surgery and this percentage has increased over 9% during the years included in this study. Preoperative opioid use was most predictive of increased refills of opioids following TKA. However, other intrinsic patient characteristics were also predictive of prolonged opioid use.

Performance of PROMIS Instruments in Patients With Shoulder Instability

Background: Shoulder instability is a relatively common condition occurring in 2% of the population. PROMIS (Patient-Reported Outcome Measurement Information System) was developed by the National Institutes of Health in an effort to advance patient-reported outcome (PRO) instruments by developing question banks for major health domains. Purpose: To compare PROMIS instruments to current PRO instruments in patients who would be undergoing operative intervention for recurrent shoulder instability. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: A total of 74 patients with a primary diagnosis of shoulder instability who would be undergoing surgery were asked to fill out the American Shoulder and Elbow Surgeons shoulder assessment form (ASES), Marx shoulder activity scale (Marx), Short Form–36 Health Survey Physical Function subscale (SF-36 PF), Western Ontario Shoulder Instability Index (WOSI), PROMIS physical function computer adaptive test (PF CAT), and PROMIS upper extremity item bank (UE). Correlation between PRO instruments was defined as excellent (>0.7), excellent-good (0.61-0.7), good (0.4-0.6), and poor (0.2-0.3). Results: Utilization of the PROMIS UE demonstrated excellent correlation with the SF-36 PF (r = 0.78, P < .01) and ASES (r = 0.71, P < .01); there was excellent-good correlation with the EQ-5D (r = 0.66, P < .01), WOSI (r = 0.63, P < .01), and PROMIS PF CAT (r = 0.63, P < .01). Utilization of the PROMIS PF CAT demonstrated excellent correlation with the SF-36 PF (r = 0.72, P < .01); there was excellent-good correlation with the ASES (r = 0.67, P < .01) and PROMIS UE (r = 0.63, P < .01). When utilizing the PROMIS UE, ceiling effects were present in 28.6% of patients aged 18 to 21 years. Patients, on average, answered 4.6 ± 1.8 questions utilizing the PROMIS PF CAT. Conclusion: The PROMIS UE and PROMIS PF CAT demonstrated good to excellent correlation with common shoulder and upper extremity PRO instruments as well as the SF-36 PF in patients with shoulder instability. In patients aged ≤21 years, there were significant ceiling effects utilizing the PROMIS UE. While the PROMIS PF CAT appears appropriate for use in adults of any age, our findings demonstrate that the PROMIS UE has significant ceiling effects in patients with shoulder instability who are ≤21 years old, and we do not recommend use of the PROMIS UE in this population.

Intensive gait training for older adults with symptomatic knee osteoarthritis

ObjectiveThe objective of this study was to determine whether individualized gait training is more effective than usual care for reducing mobility disability and pain in individuals with symptomatic knee osteoarthritis. DesignAdults aged 60 yrs or older with symptomatic knee osteoarthritis and mobility limitations were randomized to physical therapist–directed gait training on an instrumented treadmill, with biofeedback individualized to optimize knee movements, biweekly for 3 mos or usual care (control). Mobility disability was defined using Late Life Function and Disability Index Basic Lower Limb Function score (primary); mobility limitations, using timed 400-m walk, chair-stand, and stair-climb tests; and symptoms, using the Knee Injury/Osteoarthritis Outcome Score at baseline, as well as at 3, 6, and 12 mos. The analyses used longitudinal mixed models. ResultsThere were no significant intergroup differences between the 35 gait-training (74.3% women; age, 69.7 ± 8.2 yrs) and 21 control (57.1% women; age, 68.9 ± 6.5 yrs) participants at baseline. At 3 mos, the gait-training participants had greater improvement in mobility disability (4.3 ± 1.7; P = 0.0162) and symptoms (8.6 ± 4.1; P = 0.0420). However, there were no intergroup differences detected for pain, 400-m walk, chair-stand, or stair-climb times at 3 mos or for any outcomes at 6 or 12 mos. ConclusionsCompared with usual care, individualized gait training resulted in immediate improvements in mobility disability knee symptoms in adults with symptomatic knee osteoarthritis, but these effects were not sustained.

Vibration Platform Training in Women at Risk for Symptomatic Knee Osteoarthritis

To determine whether a platform exercise program with vibration is more effective than platform exercise alone for improving lower limb muscle strength and power in women ages 45 to 60 with risk factors for knee osteoarthritis (OA).

The Relationship Between Greater Prepubertal Adiposity, Subsequent Age of Maturation, and Bone Strength During Adolescence.

This longitudinal study investigated whether greater prepubertal adiposity was associated with subsequent timing of maturation and bone strength during adolescence in 135 girls and 123 boys participating in the Iowa Bone Development Study. Greater adiposity was defined using body mass index (BMI) data at age 8 years to classify participants as overweight (OW, ≥85th percentile for age and sex) or healthy weight (HW). Maturation was defined as the estimated age of peak height velocity (PHV) based on a series of cross‐sectional estimates. Measurements were taken at ages 11, 13, 15, and 17 years for estimates of body composition by dual‐energy X‐ray absorptiometry (DXA), bone compression (bone strength index), and torsion strength (polar strength‐strain index) at the radius and tibia by pQCT, and femoral neck bending strength (section modulus) by hip structural analysis. Bone strength in OW versus HW were evaluated by fitting sex‐specific linear mixed models that included centered age (visit age – grand mean age of cohort) as the time variable and adjusted for change in fat mass, and limb length in model 1. Analyses were repeated using biological age (visit age – age PHV) as the time variable for model 1 with additional adjustment for lean mass in model 2. BMI was negatively associated with age of maturation (p < 0.05). OW versus HW girls had significantly greater bone strength (p < 0.001) in model 1, whereas OW versus HW boys had significantly greater bone strength (p < 0.001) at the tibia and femoral neck but not radius (p > 0.05). Analyses were repeated using biological age, which yielded reduced parameter estimates for girls but similar results for boys (model 1.) Differences were no longer present after adjustment for lean mass (model 2) in girls (p > 0.05) whereas differences at the tibia were sustained in boys (p < 0.05). These findings demonstrate sex‐ and site‐specific differences in the associations between adiposity, maturation, and bone strength.