When evaluating any periarticular pain, the realization of an accurate and timely diagnosis can be facilitated by asking the following questions:

A) Is the pain articular or non-articular? (is it in the joint or not)
B) Is the problem inflammatory?
C) Is the problem acute or chronic?
D) What is the pattern of joints involved?
E) Are there any associated signs or symptoms?

Typical rules of thumb to keep in mind in response to these questions include:
Articular or capsular pain often is associated with a global decreased range of motion instead of painful motion only in one direction. Non-articular (non-capsular) myo-fascial pain will have asymmetric restrictions in range of motion and pain in only some directions. Articular pain generators cause tenderness over the joint line while non-capsular sources are tender in a periarticular area. Intra-articular pain generators are usually associated with an effusion of the affected joint.. It is vital in evaluating knee pain to always carefully examine the hip and back as these are frequent generators of perceived knee pain.

Many patients with degenerative cartilage wear have both OA and degenerative tears of menisci or the labrum. In the knee, degenerative tears of the medial meniscus are the most common form of meniscal tear and are commonly concurrent with significant articular cartilage wear. The productive changes of sclerosis and osteophytes are easily seen on plain films while meniscal or labral tears are not seen but “tipped off” by clicking and locking of the affected joint(mechanical symptoms) with deep flexion and extension.

Whatever the etiology, intra-articular injections with bupivacaine and depomedrol are not only therapeutic but diagnostic as pain relief with injection signals intra-articular pathology. Additionally, perceived shoulder pain is often attributable to neck and diaphragm pathology and should always be considered. Periarticular myofascial pain generators often will be reproducible with defined tests such as the Finkelstein test (deQuervain’s), pain with resisted wrist dorsi-flexion (tennis elbow) and point tenderness over the greater trochanter (trochanteric bursitis) among many others.

Inflammatory articular problems will have morning stiffness > 30 minutes, with swelling and warmth of the affected joint and occasional redness is seen in septic arthritis specifically. Non-inflammatory pain usually lasts less than 30 minutes and gets worse throughout the day while inflammatory stiffness loosens with time. The hall mark of inflammatory arthropathy is synovitis. Synovitis is appreciated clinically as spongy swelling around the joint and can be defined by arthrocentesis and cell count. OA will have only minimal joint swelling but will often demonstrate bony enlargement of effected joints (e.g. Heberdens nodes). Acute inflammatory problems arise quickly within 6 weeks while chronic problems are obviously more insidious lasting longer than 6 weeks.

Diseases like rheumatoid arthritis (RA) have symmetric joint involvement and often affect the hands and feet. The radiographic hallmark of RA is erosions. However, gout and all other inflammatory arthropathies can cause erosions as well. Many rheumatological disorders have associated signs and symptoms like Sicca and therefore asking about dry eyes and mouth is always a good review of symptoms question when you think the pain is inflammatory in nature. Once the patient has been examined you can turn your attention to imaging studies that can confirm your suspicion and direct your treatment as to the etiology of pain.