The Contributive Role of IGFBP-3 and Mitochondria in Synoviocyte-Induced Osteoarthritis through Hypoxia/Reoxygenation Injury: A Pathogenesis-Focused Literature Review

Table 1

Clinical features of OA by joint site.

Site-joint OA	Characteristics	Ref.
Knee OA	Knee osteoarthritis is very common, comprising the largest proportion of all cases and affecting 12.4 million (33.6%) adults over the age of 65. There are five phenotypes: (a) minimal joint disease phenotype, (b) strong muscle phenotype, (c) nonobese and weak muscle phenotype, (d) obese and weak muscle phenotype, and (d) depressive phenotype.	[23, 25]
Hip OA	Hip osteoarthritis stands for 13% in osteoarthritic patients and a major cause of pain and disability in the elderly population. Three different subtypes (normotrophic, hypertrophic, and atrophic) of hip OA have been considered nowadays.	[24, 26]
Shoulder OA	Shoulder OA is the final diagnosis in 5% of those who report shoulder pain, affecting up to 32.8% of patients over the age of sixty years. Its prevalence increases with age, and women appear to be more susceptible than men.	[24, 27]
Hand OA	Hand OA affects 26% of women and 13% of men over the age of 71.	[28].
Ankle OA	Ankle OA has a prevalence of less than 1% of the world’s adult population. Approximately 30% of ankle OA cases are idiopathic and affect a relatively younger population as compared with other OA joint afflictions.	[24, 29]
Elbow OA	OA is far less common at the elbow than at the other upper limb joints and even seems rare. Symptomatic elbow OA is a relatively rare condition that comprises only up to 2% of patients with elbow arthritis and almost exclusive to males. According to the joint side involved, the elbow OA can be categorized as humeroradial OA and humeroulnar OA.	[24, 30]
Lumbar spine OA	Lumbar spine osteoarthritis (OA) is very common, with estimates of prevalence ranging from 40 to 85%. Facet joint osteoarthritis (FJOA) is a common disease widely prevalent in older adults causing low back and lower extremity pain.	[31, 32]
Temporomandibular joint OA	Little focus is given to the incidence of temporomandibular joint (TMJ) OA, although it may lead to dental malocclusion and reduced health-related quality of life. In an age group of 9-90 years, the percentage of TMJ OA ranges from 28% to 38% and the incidence increases with advancing age.	[33, 34]