Pain in joints can arise from the bone.
It may arise from joint ligaments or tendons.
It may arise from adjacent tissues including muscle and fascia.
Occasionally it may arise from diseases outside the joints and bones.
A very important cause of joint pain is that related to diseases of the enthesis.
The enthesis has plenty of adjacent nerve endings that sense pain [ see Nerve Supply of the Enthesis and Pain Mechanisms ].
Because the enthesis is anchored to the skeleton like the roots of a tree to the ground pain related to enthesitis and enthesopathy may emanate from the underlying bone.
Enthesitis and Enthesopathy may also cause pain along the bone surface or periostium.
Pain emanating from the bone surface may be associated with tenderness but the deeper pain may not linked to tenderness.
This is why the patient with early Ankylosing Spondylitis may complain of lots of pain and stiffness but the examining doctor may find no abnormalities.
Stiffness around a joint without swelling may be due to enthesis inflammation.
The stiffness is thought to be due to excessive fluid accumulation as a result of inflammation.
Joint activity and movement is associated with an improvement in the stiffness.
Collectively the fact that many entheses are situated deep inside the spine makes medical recognition difficult, especially given the poor understanding of the importance of the enthesis in disease.
Even when an enthesis is located superficially an examining doctor may find no swelling and not suspect the diagnosis.
The enthesis is a major cause of mystery pain emanating from the skeleton and contributes to the long delay in diagnosis Ankylosing Spondylitis and other disorders of the enthesis.
This website is devoted to providing an improved understanding of pain caused by enthesitis and enthesopathy and its diagnosis and treatment.