Knee Pain Predicts Subsequent Shoulder Pain and the Association Is Mediated by Leg Weakness: Longitudinal Observational Data from the Osteoarthritis Initiative

Abstract

Objective: To assess whether the 'spread' of joint pain is related to pain-associated muscle loss in one joint leading to increased loading and subsequent pain in other joints. Methods:Associations between persistent knee pain (pain in one or two knees over years 0-3 versus no persistent pain) and incident shoulder pain at year 4 were examined in participants from the longitudinal NIH Osteoarthritis Initiative (OAI).Associations were assessed using log multinomial modelling, adjusted for age, sex, BMI, depression score, other lower limb pain and baseline leg weakness (difficulty standing from a sitting position). Results:In older adults with clinically significant knee OA or at risk of knee OA (n=3486), the number of painful joints increased yearly, from 2.1 joints (95% CI 2.0, 2.2) at baseline increasing by 5.2% (95% CI 2.2%, 8.3%) at year 4. Shoulders were the next most commonly affected joint after knees (28.5%). Persistent pain in 1 or 2 knees increased risk of bilateral shoulder pain at year 4 (1 knee RR 1.59 (95% CI 0.97, 2.61); 2 knees RR 2.02 (1.17, 3.49)) after adjustment for confounders. Further adjustment for leg weakness attenuated effect sizes (1 knee RR 1.13 (95% CI 0.60, Page 2 2.11); 2 knees RR 1.44 (0.75, 2.77)), indicating mediation by functional leg weakness. Conclusions:Spread of joint pain is not random. Persistently painful knees predict new bilateral shoulder pain, which is likely mediated by leg weakness; suggesting that biomechanical factors influence the spread of pain.

Methylene blue relieves the development of osteoarthritis by upregulating lncRNA MEG3

“…Osteoarthritis is the most common type of joint disease; patients may develop stiff joints which are painful to move ( 1 , 2 ). Chronic pain is a major problem for millions of patients with OA ( 3 ) and the key focus of OA treatment is to reduce pain and improve joint function. However, for older patients, relieving pain is considered to be more important than improving joint function ( 4 , 5 ).…”

High-fat/high-sucrose diet-induced obesity results in joint-specific development of osteoarthritis-like degeneration in a rat model

“…In symptomatic OA, shoulder pain predicts knee pain, suggesting that a pathophysiological link may exist between the multi-joint arthritis of these two synovial joints. 15 The link between knee and shoulder pain with OA is proposed to be mediated by functional muscle weakness, 15 implicating a role for skeletal muscle in metabolic OA of different synovial joints. Compromised vastus lateralis (VL) muscle integrity is associated with significant increases in knee Modified Mankin score in this model system 35 .…”

“… 12 - 14 In patients with knee OA, shoulder OA is the next most common site of OA. 15 A high prevalence of shoulder pain is reported in individuals with obesity compared with controls of normal weight, and there is a significant connection between obesity and shoulder repair surgery. 16 …”

Data From Clinical and Instrumental Examinations of Patients With Chronic Pain in the Shoulder Joint

“…L. Laslett и соавт. [23] в рамках международного исследования Osteoarthritis Initiative («Инициатива по остеоартриту») оценили развитие боли в плече у 3486 пациентов с ранним ОА КС. Было показано, что частота ХБОП у них составляла 28%, а наличие билатерального поражения КС увеличивало риск развития боли в плече более чем в 2 раза: относительный риск 2,02 (95% доверительный интервал 1,17-3,49).…”