[Possibilities and limits of conservative treatment for osteoarthritis : Sport advice, training therapy, orthotics and cartilage therapeutics]

Sensorimotor or Balance Training to Increase Knee-Extensor and Knee-Flexor Maximal Strength in Patients With Knee Osteoarthritis: A Critically Appraised Topic

CLINICAL SCENARIO

Knee osteoarthritis (KOA) is a complex progressive synovial joint disease that results in impaired muscle function, including a considerable loss of maximal strength and power. Exercise therapies, such as sensorimotor or balance training and resistance training, are frequently used to improve muscle function, mobility, and quality of life, but their impact on maximal muscle strength in patients with KOA is not well understood.

FOCUSED CLINICAL QUESTION

Does sensorimotor or balance training improve knee-extensor and knee-flexor maximal muscle strength compared with strength training or no intervention in patients with KOA?

SUMMARY OF KEY FINDINGS

Results from 4 fair- to good-quality randomized controlled/clinical trials (level 1b) revealed inconsistent grade B evidence regarding the effect of sensorimotor or balance training to improve knee-extensor and knee-flexor maximal muscle strength in patients with KOA. Two studies, one good-quality study and one fair-quality study, showed significant strength improvements, and 2 good-quality studies demonstrated no significant strength enhancements.

CLINICAL BOTTOM LINE

Sensorimotor or balance training may be useful to improve maximal strength of quadriceps and hamstring muscle groups in patients with KOA; however, it seems that this depends on a training duration of at least 8 weeks and the use of unstable devices to induce destabilization of patients' balance, initiating neuromuscular adaptations.

STRENGTH OF RECOMMENDATION

Due to inconsistent evidence (grade B), the true effect of sensorimotor or balance training to improve knee-extensor and knee-flexor maximal muscle strength in patients with KOA remains unclear and needs to be further investigated.

[Osteoarthritis: what's new?]

Osteoarthritis (OA) is a very common disease. As a consequence of the ageing society, osteoarthritis prevalence will further increase. Age itself, trauma, unequal load distribution and overweight are risk factors. Cellular senescence and overweight have been in the focus of scientific interest for the last few years. Both risk factors are able to facilitate joint inflammation, independent of a mechanical approach. Senescent chondrocytes as well as adipocytes can produce increased amounts of inflammatory cytokines. Cornerstones of the therapy are patient education including information on the character/course of the disease and intentional weight loss. Although NSAIDs can be recommended as analgesics, their contraindications limit the widespread use. Alternatively, acetaminophen or low-potency opioids such as tramadol might be considered. Topical NSAIDs and intraarticular glucocorticoid injections can be helpful in pain reduction particularly in knee osteoarthritis. There is still no general recommendation for nutritional supplements including chondroitin or glycosaminoglycan, but they might be considered as an accompanying therapy. With the current non-approval of the nerve growth factor (NGF)-antibody tanezumab, a new therapeutical option for OA suffered a setback. Unfortunately, the results of the phase 2 study on the Wnt inhibitor lorecivivint are barely encouraging. However, the results of the according phase 3 study are eagerly awaited.