Proximal myofascial pain in patients with distal complex regional pain syndrome of the upper limb.

BACKGROUND: Patients suffering from complex regional pain syndrome (CRPS) endure myofascial-related pain in at least 50% of cases. AIMS: To evaluate the association of upper limb CRPS with myofascial pain in muscles that might influence arm or hand pain, and to evaluate whether the paraspinal skin and subcutaneous layers' tenderness and allodynia are associated with CRPS. METHODS: A case-control study comprising 20 patients presenting with upper limb CRPS, and 20 healthy controls matched for sex and age, were evaluated in the thoracic paraspinal area and myofascial trigger points (MTrPs) (infraspinatus, rhomboids, subclavius, serratus posterior superior and pectoralis minor) via a skin rolling test. RESULTS: The prevalence of MTrPs in the affected extremity of the subjects was significantly higher than in the right limb of the controls: 45% exhibited active and latent MTrPs in the infraspinatus muscle (χ2 = 11.613, p = 0.001); 60% in active and latent MTrPs in the subclavius muscle (χ2 = 17.143, p < 0.001); and in the pectoralis minor muscle (χ2 = 13.786, p < 0.001). In addition, 55% of the cases exhibited active and latent MTrPs in the serratus posterior superior muscle (χ2 = 15.172, p < 0.001). Significant differences between the groups in skin texture and pain levels (p = 0.01, p < 0.001, respectively) demonstrated that CRPS patients felt more pain, and their skin and subcutaneous layers were much tighter than in the healthy controls. CONCLUSION: There is a high prevalence of MTrPs in the shoulder and upper thoracic area muscles in subjects who suffer from CRPS. We recommend adding an MTrPs evaluation to the standardized examination of these patients.

A myofascial component of pain in knee osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is the most common cause of musculoskeletal pain and disability. The knee is the most common site of OA. Numerous studies have shown an inconsistency between patients' reports of pain and their radiographic findings. This inconsistency may be partially explained by the fact that a portion of the pain originates from the myofascial trigger points (MTrPs) located in the surrounding muscles. AIM: To assess the role of myofascial pain in OA patients. METHODS: Critical review. PubMed, Google Scholar, Scopus, and PEDro databases were searched from inception until December 2016 for the following keywords: "myofascial pain", "osteoarthritis", "trigger points", "knee" or any combination of these words. The reference lists of all articles retrieved were searched as well. RESULTS: The current review included two observational studies evaluating the prevalence of MTrPs in OA patients and six interventional studies describing the treatment of myofascial pain in OA patients. Data from two of the interventional studies also included an observational section. CONCLUSION: The reviewed observational studies offered initial evidence as to the assumption that myofascial pain and the presence of MTrPs may play a role in pain and disability of knee OA. Because of the cross-sectional design of these studies, the causal relationships could not be established. Additional studies are needed to confirm this assumption as well as to clarify if MTrPs are a portion of OA etiology or that OA is the basis for MTrPs formation. Each interventional study elaborated on various myofascial treatment techniques. However, treatment focusing on MTrPs seems to be effective in reducing pain and improving function in OA patients. Due to the heterogeneity in treatment methods and outcome measures, it is difficult to attain a definite conclusion and therefore, additional high-quality randomized controlled trials are warranted.