Evaluating
Periarticular Pain in the Clinic:
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.