Mucoid change or mucoid degeneration refers to the irreversible tissue degeneration due to the accumulation of mucin within the fibers of tendons, ligaments and fibrocartilage.
The likelihood of mucoid change within ligaments and tendons increases with age 1.
Predisposing factors include the following 1:
- mechanical repetitive stress
- traumatic injury
Mucoid change is associated with the following conditions 2:
The clinical presentation mucoid change and includes pain, restricted range of motion and stiffness dependent on the localization 2,3.
Complications of mucoid change include the following 1-3:
Histologically mucoid change is characterized by the degradation and disorganization of collagen fibers and the deposition of a mucoid substance containing new glycosaminoglycans within those fibers 1-7.
Tendons and ligaments and fibrocartilage can be affected by the mucoid change, in particular, the following 6-10:
- Achilles tendon
- quadriceps tendon
- biceps tendon
- rotator cuff
- anterior and posterior cruciate ligaments
- triangular fibrocartilage complex
Mucoid change can be seen on ultrasound or MRI.
Ligaments and tendons affected by mucoid change might display a thickened and/or ill-defined appearance characterized by nonspecific linear or globular increase in signal intensity.
Mucoid change shows increased signal intensity on all pulse sequences typically easily definable on T2 weighted and fat-saturated images, but poorly distinguishable on non-fat saturated PD weighted images 6,7.
T1/PD: intermediate to mildly hyperintense
The radiological report should include a description of the following:
- location of the mucoid change within tendons and/or ligaments
- any associated partial or complete tears
- signs of impingement
- associated findings as degenerative joint disease
Treatment and prognosis
Treatment is only required if there are otherwise unexplained symptoms. It is then conservative and includes exercise therapy, activity modification, physical and manual therapy as well as nonsteroidal antiinflammatory drugs ref.
Surgical treatment options depend on the specific location and include debridement and or partial excision in patients with refractory severe symptoms and impingement unresponsive to conservative treatment options 3.
Conditions which can mimic the presentation and/or the appearance of mucoid change include 1,2:
- chondral metaplasia
- fatty infiltration
- ligamental sprain
- partial or interstitial tendon tear
- ganglion cysts
- synovial chondromatosis
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