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As we noted in the introduction, most rheumatologic diseases have some component of joint involvement. However, not all joint complaints are due to rheumatologic diseases!  Before we dive into the details of the different joint and systemic pathologies, we will review some of the general principles used to help narrow in on the different categories of complaints brought up by patients.

Taking a history: 4 patterns to Chronic Joint Pain:

Often patients presenting with musculoskeletal complaints will present with certain historical features. Pain, loss of motion, weakness, and difficulty with activities of daily living are common manifestations of musculoskeletal problems. Asking key questions can help you to differentiate between these broad categories of etiologies.

• Mechanical:
  • The hallmark of mechanical joint pain is pain that worsens with activity or use of the affected structure. Often this means that symptoms will be worse toward the end of the day. Morning stiffness, if present, is usually minimal (less than 10 minutes).  Swelling may or may not be present depending on the degree of tissue injury. Patients with a primarily mechanical cause for joint pain do not have systemic symptoms such as fevers, fatigue or rashes.  Ex. Osteoarthritis, rotator cuff tendonitis Key question: What have you noticed that makes your pain worse?
• Inflammatory:
  • In contrast, patients with joint pain from inflammatory joint processes tend to have prominent morning stiffness, frequently lasting more then 30 minutes to hours. Interestingly, pain may be mild and also tends to be worse first thing in the morning. There is some thought that this pattern is due to circadian rhythms related to cytokine release that peak in the early morning hours.  Patients’ symptoms tend to improve with movement up to a certain point. Heat is often noted to be helpful as well. Stiffness and pain may recur after prolonged periods of inactivity, such as a long car ride, often referred to as ‘gelling’ phenomenon. Mild swelling is common but not always noted by patients. Patients may have associated feelings of fatigue, occasionally fevers and other signs of systemic inflammation (anemia, rashes, weight loss for example). Ex. Rheumatoid arthritis, spondyloarthropathy Key question(s): How do your joints feel first thing in the morning? 
• Referred/Neurologic:
  • Pain from compression of a nerve can ‘refer’ along the sensory dermatome innervated by the nervous structure. Pain is frequently sharp or burning and can be associated with sensory symptoms such as tingling or numbness and can often be worse at night. Although the pain does not worsen with isolated range of motion of joint, exam maneuvers that compress or stretch the affected structure reproduce the symptoms. Ex. Sciatica, cervical radiculopathy Key Question(s): Is there any numbness or tingling associated with your pain? Does it wake you from sleep?
• Myofascial/Widespread Pain:
  • This is a very important but poorly understood form of pain. Our current hypotheses focus on disruption of central pain inhibitory mechanisms resulting in generalized pain. Pain is often constant, diffuse and not improved by activity or rest. Patients can have morning stiffness, but it tends to last all day and does not vary or respond to medications like ibuprofen or other NSAIDs. Patients may have concomitant sleep disruption, fatigue and memory problems (‘brain fog’) as well as other somatic complaints but true signs of inflammation (fever, rashes, etc.) should raise suspicion for alternative causes. Pain is often localized to ‘trigger points’ which tend to be in the central region of larger muscle groups found in a symmetric distribution. These patients should not have objective weakness nor focal sensory findings. These disorders can co-exist in patients with inflammatory diseases and sometimes can be difficult to distinguish from the underlying inflammatory disorder. Ex. Fibromyalgia Key Question(s): Have you found anything that makes your pain better or worse? Do you feel well rested when you wake in the morning?

Performing the Physical exam:  4 “S” functions of Synovial Joints:

After performing a history to generate an initial list of suspected causes for joint complaints, the physical exam can be used to narrow the differential diagnosis and direct further testing. There are four essential mechanical functions of a synovial joint:

1. To move through a range (not be stiff)
2. To be strong
3. To be stable,
4. To move smoothly.

Anything that interferes with one or more of these functions will result in a musculoskeletal or biomechanical problem.  Understanding neuro/musculoskeletal anatomy and movement-related functions will help you to use your physical exam to help determine the source of the problem and potential treatment options.  

As an example, let’s consider a patient whose complaint is that they are having trouble performing important tasks of daily life such as brushing teeth and combing hair.  There is no morning stiffness, but they notice difficulty using their right elbow and a sense of burning pain down their arm. You examine the patient and find limited active range of motion of the elbow joint due to lack of strength (weakness). Yet when you (the examiner) take the forearm and passively range the elbow, you find normal passive range of motion – full flexibility. This situation may occur if there is a nerve injury or neuromuscular weakness. In contrast, if the motion of the joint were limited in the case of a primary joint problem such as arthritis, you would find no difference between active movement (by the patient) and passive movement (by the examiner). The presence of an intra-articular, space occupying lesion causes the patient to try to maintain a ‘position of comfort’ that maximizes the space available in the joint. Often this is a neutral position, and extreme ranges of flexion or extension are lost due to compression of the fixed space available. Particularly in younger or nonverbal patients, paying close attention to the preferred resting position of the extremities and noticing asymmetries from side to side can provide clues as to the affected joints.

Let’s think a bit more in detail about each of these functions.