Functioning Without Cartilage: Older People With Radiographic Knee Osteoarthritis Who Self-Report No Functional Limitations Do Score Lower on a Performance Battery

Investigation of the validity and reliability of the short physical performance battery in patients undergoing total knee arthroplasty

BACKGROUND

Practical, applicable, valid, and reliable tools are needed to assess physical performance in patients with Total Knee Arthroplasty (TKA) in a variety of settings, including routine clinical assessment, research studies, and community-based programs.

OBJECTIVE

The aim of this study is to evaluate the validity and reliability of the Short Physical Performance Battery (SPPB) among patients with TKA.

METHODS

We included 45 patients who underwent TKA surgery (mean age 68.89 ± 9.26). The SPPB, Timed up and go (TUG) test and, Hospital for Special Surgery (HSS) Knee Score were administered to the patients. SPPB was performed twice on the same day with 1 h rest.

RESULTS

The ICC(2,1) coefficient, MDC95 and SEM values were 0.97, 1.02 and 0.37 respectively. The Pearson correlation coefficient of the SPPB with the TUG and HSS was -.78, and 0.74 respectively.

CONCLUSION

SPPB has excellent reliability, and strong validity in assessing physical performance in patients with TKA. SPPB can identify even minimal detectable difference in physical performance and can be reliably used to monitor patient outcomes in the postoperative period for a comprehensive assessment of TKA in many physical performance domains, including balance, walking speed, and lower extremity strength.

CLINICAL TRIAL NUMBER

NCT06201637.

Neuromuscular joint function in knee osteoarthritis: A systematic review and meta-analysis

BACKGROUND

Neuromuscular alterations are common in people with knee osteoarthritis (KOA). A comprehensive understanding of these alterations is important to enable targeted rehabilitation strategies.

OBJECTIVES

This systematic review and meta-analysis aimed to comprehensively understand the neuromuscular alterations around the knee joint in people with KOA.

METHODS

Moderate- and high-quality studies based on a modified version of the Downs and Black checklist, comparing neuromuscular function of peri‑articular muscles between people with KOA and controls were retrieved from five databases from inception to October 2020. Outcomes included normalized isokinetic strength, muscle size, voluntary activation, cortical and spinal-reflex excitability, and torque-related outcomes. Data were pooled according to structural KOA severity with sensitivity analysis based on sex. Evidence levels are presented in evidence gap maps.

RESULTS

A total of 7 high-quality and 22 moderate-quality studies were retained (1146 people with KOA and 1353 age- and sex-matched controls). Studies demonstrated quadriceps and hamstring strength deficits and increased hamstring-to-quadriceps strength ratios across KOA severities. Women presented lower quadriceps strength at early KOA (very limited evidence) and lower voluntary activation at end stage KOA (very limited evidence) as compared with controls, whereas men did not (moderate evidence). People with KOA also demonstrated lower quadriceps force control ability with no change in rapid force production (very limited evidence). Voluntary activation deficits for quadriceps were evident (moderate evidence), with no change in quadriceps cortical excitability (very limited evidence) or soleus spinal reflexes (very limited evidence). No muscle size change was demonstrated except for the vastus medialis (limited evidence). Evidence gaps were found for neural and torque-related measures and differences in hamstring, gastrocnemius, soleus, and popliteus.

CONCLUSIONS

Neuromuscular deficits are evident across different structural KOA severities and are seen in muscle strength, voluntary activation, muscle size, and force control ability. Women may exhibit these alterations to a greater extent than men.

PROSPERO REGISTRATION NUMBER

CRD42019160845.

Effects of a dynamic combined training on impulse response for middle-aged and elderly patients with osteoporosis and knee osteoarthritis: a randomized control trial

Dynamic combined training is a crucial component in treating musculoskeletal conditions to increase muscle strength and improve functional ability. This randomized control trial aimed to examine the effect of dynamic combined training on muscle strength and contractile rate of force development (RFD) in patients with osteoporosis (OP) and knee osteoarthritis (KOA). 58 participants with OP or KOA were randomly assigned to a control group (CG) (CGOP, n = 12; CGKOA, n = 15) or training group (TG) (TGOP, n = 14; TGKOA, n = 17). The training group participated in a 12-week, three-days-per-week supervised program consisting of stretching and warm-up exercises (10 min), hydraulic resistance training (40 min), and cool-down and relaxation exercises (10 min). All participants were evaluated at baseline and post-training. The maximal voluntary contraction (MVC) and contractile RFD at 0-200 ms increased significantly in middle-aged and older patients with OP. As for KOA, the dynamic combined training program was effective in improving the muscle strength. The maximal voluntary contraction (MVC) and contractile RFD at 0-200 ms increased significantly (by 29.22%, P = .000 and 27.25%, P = .019, respectively) in middle-aged and older patients with OP. In the KOA group, MVC and contractile RFD improved but did not reach statistical significance. The dynamic combined training program is effective for health promotion in older adults with OP or KOA.

Patient-specific reference values for objective physical function tests: data from the Osteoarthritis Initiative

INTRODUCTION/OBJECTIVE

We aimed to establish sex-specific reference values of objective physical function tests among individuals with or at risk for knee osteoarthritis (KOA) across subsets of age, radiographic KOA severity, and body mass index (BMI).

METHOD

We included Osteoarthritis Initiative participants with data for objective physical function tests, sex, age, BMI, and radiographic KOA severity (Kellgren-Lawrence [KL] grade) at baseline. Objective physical function was quantified with 20-m walk speed, chair-stand speed, 400-m walk time, and knee extension and flexion strength. We created participant characteristic subsets for sex, age, KL grade, and BMI. Reference values were created as percentiles from minimum to maximum in 10% increments for each combination of participant characteristic subsets. Previously established clinically important differences for 20-m walk speed and knee extension strength were used to highlight clinically relevant differences.

RESULTS

Objective physical function reference values tables and an interactive reference value table were created across all combinations of sex, age, KL grade, and BMI among 3860 individuals with or at risk for KOA. Clinically relevant differences exist for 20-m walk speed and knee extension strength between males and females across age groups, KL grades, and BMI categories.

CONCLUSIONS

Establishing an individual's relative level of objective physical function by comparing their performance to individuals with similar sex, age, KL grade, or BMI may help improve interpretation of physical function performance. The interactive reference value table will provide clinicians and researchers a clinically accessible avenue to use these reference values.Key Points• Since greater age, radiographic knee osteoarthritis severity, and body mass index are all associated with worse objective physical function, reference values should consider the complex inter-play among these patient characteristics.• This study provides objective physical function reference values among subsets of individuals across the spectrum of sex, age groups, radiographic knee osteoarthritis severity, and body mass index categories.• These reference values offer a more patient-centered approach for interpreting an individual's relative level of objective physical function by comparing them to a more homogeneous group of individuals with similar participant characteristics.• We have provided a clinically accessible interactive table that will enable clinicians and researchers to input their patient's data to quickly and efficiently determine a patient's relative objective physical function compared to individual's with similar characteristics.

Validation of Physical Performance Tests in Individuals with Advanced Knee Osteoarthritis

BACKGROUND

Individuals with advanced osteoarthritis (OA) of the knee experience significant impairments in balance and in essential physical functions such as walking and rising from a chair. There is limited evidence on valid outcome measures to capture these impairments.

QUESTIONS/PURPOSES

We sought to examine the construct validity of three physical performance measures in patients with advanced knee OA: a gait speed (GS) test, the Short Physical Performance Battery (SPPB), and the Timed Up and Go (TUG) test.

METHODS

We designed a cross-sectional clinical measurement study in which patients with advanced knee OA completed two self-reported measures: the Knee Injury and Osteoarthritis Outcome Score-Physical Function Shortform (KOOS-PS) and a four-part numeric pain rating scale (Q-NPRS). They were also administered the GS test, TUG test, and SPPB. Convergent and divergent construct validity were assessed by examining relationships between the GS test, the SPPB, the TUG test, the KOOS-PS, and the Q-NPRS and calculating Pearson correlation coefficients (r). The scores for the GS, TUG test, and SPPB were compared with established normative values for age-matched healthy controls.

RESULTS

Forty-four subjects (mean age, 66.9 ± 8.1 years) participated in the study. The GS test showed low concordance with the SPPB component tests and the TUG test. The relationships between the physical performance measures and the self-reported measures were low. The scores for the GS test, TUG test, and SPPB in our sample were significantly worse when compared with age-matched normative values, indicating impairments in physical performance.

CONCLUSION

These results advance the understanding of the validity of the GS test, TUG test, and SPPB in demonstrating the impairments in physical performance that patients with advanced knee OA experience in walking, balancing, and rising from a chair. Future research should examine the reproducibility and responsiveness of the GS test, TUG test, and SPPB in patients with advanced knee OA, in order to facilitate the integration of these measures into clinical practice.

Angiotensin-Converting Enzyme Insertion/Deletion Polymorphism, Lower Extremity Strength, and Physical Performance in Older Adults

BACKGROUND

Evidence for associations between the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene and physical performance is conflicting. Furthermore, investigations of relationships between lower extremity strength and physical performance have usually not considered the role of the ACE genotype, and it is unclear whether there are variations in relationships between lower extremity strength and physical performance among ACE genotypes in older adults.

OBJECTIVE

The objectives of this study were to investigate associations between the ACE I/D polymorphism and physical performance and to determine whether relationships between lower extremity strength and physical performance vary among ACE genotypes in older adults.

DESIGN

This was a cross-sectional observational study.

METHODS

Community-dwelling adults (N = 88) who were at least 60 years old completed physical performance and lower extremity strength tests. After DNA was extracted from saliva, ACE I/D polymorphism genotyping was done. The Spearman rank order correlation coefficient was used to examine associations between lower extremity strength and physical performance within ACE genotype subgroups. Analysis of covariance and linear regression were used to examine ACE genotype and ACE genotype × lower extremity strength interaction effects in relation to physical performance.

RESULTS

Genotype-specific correlation coefficients exhibited substantial variation among ACE genotype subgroups; however, differences did not attain statistical significance. Statistically significant genotype × lower extremity strength interaction effects in relation to physical performance were detected.

LIMITATIONS

The cross-sectional design precludes inferring causal relationships between strength and performance. The small sample size contributed to limited power to detect additional interaction effects and to detect statistically significant differences between correlation coefficients among ACE genotype subgroups.

CONCLUSIONS

The ACE I/D polymorphism is, interactively with lower extremity strength, associated with physical performance. Genotype-specific correlation coefficients and ACE genotype × lower extremity strength interaction effects on physical performance are consistent with variations in relationships between lower extremity strength and performance among ACE genotype subgroups.

Osteoarthritis and intervertebral disc degeneration: Quite different, quite similar

Intervertebral disc degeneration describes the vicious cycle of the deterioration of intervertebral discs and can eventually result in degenerative disc disease (DDD), which is accompanied by low-back pain, the musculoskeletal disorder with the largest socioeconomic impact world-wide. In more severe stages, intervertebral disc degeneration is accompanied by loss of joint space, subchondral sclerosis, and osteophytes, similar to osteoarthritis (OA) in the articular joint. Inspired by this resemblance, we investigated the analogy between human intervertebral discs and articular joints. Although embryonic origin and anatomy suggest substantial differences between the two types of joint, some features of cell physiology and extracellular matrix in the nucleus pulposus and articular cartilage share numerous parallels. Moreover, there are great similarities in the response to mechanical loading and the matrix-degrading factors involved in the cascade of degeneration in both tissues. This suggests that the local environment of the cell is more important to its behavior than embryonic origin. Nevertheless, OA is widely regarded as a true disease, while intervertebral disc degeneration is often regarded as a radiological finding and DDD is undervalued as a cause of chronic low-back pain by clinicians, patients and society. Emphasizing the similarities rather than the differences between the two diseases may create more awareness in the clinic, improve diagnostics in DDD, and provide cross-fertilization of clinicians and scientists involved in both intervertebral disc degeneration and OA.

Plasma miR-136 can be used to screen patients with knee osteoarthritis from healthy controls by targeting IL-17

The current study mainly evaluated the plasma level of microRNA (miR)-136 in knee osteoarthritis (KOA) patients and determined if miR-136 could be used as a potential biomarker to screen KOA patients from healthy controls. It was demonstrated that plasma miR-136 was significantly decreased in the plasma of KOA patients. Moreover, the reduction in plasma miR-136 negatively correlated with the severity of KOA. Additionally, the increase in the serum interleukin (IL)-17 level positively correlated with the severity of KOA. More importantly, dual luciferase assays and western blot assays indicated that IL-17 was a target gene of miR-136. Further analysis showed that plasma miR-136 could be used as a biomarker to screen KOA patients from healthy controls. In summary, for the first time, the present study revealed that through targeting IL-17, decreased plasma miR-136 levels could be used as a potential biomarker to screen KOA patients from healthy controls.