Osteoarthritis is a disease of altered chemistry of the articular cartilage in synovial joints (joint lined by a synovial membrane), and causes roughness of the surfaces of the joint, deformity of the bone (particularly at the central parts of the joint surfaces), extra bone at the margins of the joint (osteophytes), and swelling due to accumulation of viscid joint fluid.
The joint stiffens, movement is limited, and the surfaces continue to wear, so creating a vicious cycle. Inflammatory arthritis, such as rheumatoid arthritis, can lead to all these changes but the architecture of the surfaces is damaged at the periphery of the joint first. This is where the tendons of the rotator cuff (RC) attach, so in this type of arthritis the condition of the RC is also a major concern, and tears of the RC are common. This changes the type of shoulder replacement that we can use for the restoration of pain-free functional movement.
If the surface of a joint becomes damaged due to a fracture or arthritis then it may grate or click when it rubs over a neighbouring surface. Lots of little but similar clicks suggest that the whole surface is rough, while loud and differing clicks (particularly with restriction of movement in one or more direction[s]) suggest that the edges of the joint are rough and obstructing motion. Fortunately the clicks are usually obvious and their origin relatively readily identified.
Arthritis in the shoulder joint
The shoulder joint tends to lose outward rotation first, followed by inward rotation (so that it becomes difficult to put the hand behind the back), and lastly loses elevation. X-rays are usually very clear, although an MRI scan can be helpful to understand what condition the RC is in. Sometimes people with arthritis in the shoulder joint experience a roughness which causes clicking (“crepitation”) throughout the range of (limited) motion, and often leads to a sense of displacement of the shoulder (felt as “jumping”, “catching”, or “locking”).
Arthritis in outer end of collar bone
Arthritis of the joint at the outer end of the collar bone (the ACJ - see above) causes deformity and swelling, which can impair the surface of the RC underneath. Inside the joint cavity is a fibrous disc of tissue (the ‘meniscus’ or ‘disc’) which is thought to help distribute the stress of movement through the clavicle. This wears out quite quickly so that by the time we are about 40 years old it hardly remains (dePalma, 1960). However the remnants do jam, buckle, and prolapse through the lower aspect of the joint to cause pain, especially on moving the arm across the body. Injections can help the pain (often temporarily), and removal of the disc and the damaged end of the clavicle is often the best way to be rid of the problem, with a high probability of success using arthroscopic surgery.
Arthritis in the inner end of collar bone
The inner end of the collar bone (clavicle) makes a joint with the breast-bone (sternum) called the sternoclavicular joint (SCJ). Arthritis can affect this joint just like any other synovial joint. Interestingly, unlike arthritis of the ACJ which tends to be more dramatic in men, arthritis of the SCJ is more a problem for women. Fortunately it does appear to be rarer than arthritis of the ACJ. We deal with it in much the same way as arthritis of the ACJ.
Arthritis in the elbow
The elbow is a fascinating joint, or rather three joints all linked together. The arm (the humerus) makes an articulation with the two bones of the forearm (the radius on the outside of the elbow and the ulna on the inside) and these two bones make a joint together. Any or all of the joints can be affected by arthritis. If the radiohumeral joint is arthritic then palm-up rotation of the forearm and extension (straightening) of the elbow can be painful and limited. If the ulnohumeral joint is affected then both flexion (bending) and extension can be affected. Arthritis of the joint between the radius and ulna in isolation is rare but can occur after fracture of the radius (radial head fracture) and in inflammatory arthritis, and leads to palm-up and palm-down rotation pain and restriction. One catch here is the position of the ulnar nerve (which gives sensation to the little finger border of the hand and power to many of the hand muscles) which lies behind the prominent bone of the inner side of the elbow (which many will have suffered if they hit their ’funny bone’). Arthritis of the elbow can distort the ulnar nerve causing it to become irritated (so giving rise to pins-and-needles sensations) or dulled (so giving rise to numbness and weakness in the hand).
As described above the elbow can generate clicking from all three parts of the joint, but the radiohumeral joint is the most obvious, with clicking often coming from the back of the outside of the joint. A click from the back of the joint can signify arthritis of the ulnohumeral joint. In the elbow the arthritis often leads to the production of small smooth lumps of bone or cartilage like little pebbles within the joint cavity (called “loose bodies”). These can float around but eventually get jammed in the cavities of the joint, also contributing to obstruction of motion, and pain with clicking.
Shoulder blade gliding problem
The scapula (shoulder blade) moves in a complex arc over the back of the chest wall. There is a space between it and the underlying ribcage. Sometimes the scapula’s starting position is altered (for instance by poor muscle action), and sometimes its motion is altered (again by poor muscle action). This is called scapular dyskinesia. If the undersurface of the scapula rubs on the ribcage in an unusual way, the upper tip of the scapula can click on the underlying rib causing an often loud series of clunks (obvious to outside observers) and distressingly painful movement.
This condition is common, especially in young women who are coming to the end of their growing phase. It is successfully dealt with in the majority by physiotherapy and sometimes injections under the scapula. Very occasionally an arthroscopy is needed: patients are selected very carefully for this procedure and as a result the outcome is very good: movement is restored with pain relief in nearly all patients.
Related treatment information: