A patient asked me a question today that I get from time to time: “If I get one of those spinal injections…is that a cure or does it just cover up the pain?” The question is common, but answer is a little more complex and needs some background to explain fully. One of the determinants in diagnosis and treatment of orthopedic problems is the concept of mechanical versus inflammatory pain.
Mechanical Pain
Mechanical Pain arises when either normal tissue is confronted with abnormal stress, or abnormal tissue (usually shortened) is confronted with normal stress. Pain is the result, but once the mechanical stimulus is removed, the pain abates quickly. The example that I gave today was someone pinching your skin. It hurts, but if you were only pinched once, and not terribly hard, then the pain goes away quickly.
Inflammatory Pain
Inflammatory pain, on the other hand, does not abate quickly. It can be initially caused by a mechanical stimulus, but the body’s inflammatory response has been elicited to initiate clean-up and healing. Inflammatory problems can many times be caused or aggravated by mechanical forces. Referring to the pinching example – someone pinches you once and it hurts, then you’re fine. However, if someone pinches you hard, and does so thirty or forty times in a row, and it’s likely that the area will stay red and hurt for a while. It might even swell and bruise.
Type of Pain as a Basis For Treatment
Inflammatory pain responds well to inflammatory treatment – namely anti-inflammatories. They can take the form of non-steroidal anti-inflammatories (NSAIDs), the form of corticosteroids, or physical modalities like cold packs, electrical stimulation, or compression. Most people are familiar with NSAIDs, such as Motrin, Naprosyn, Celebrex, etc. Anti-inflammatories (without getting into a long discussion on inflammation) also exhibit pain relieving effects. Mechanical pain responds well to mechanical treatment.
Mechanical treatment is targeted to a specific tissue, tissue group, or area, and is meant to change a mechanical property of that tissue. For example, increasing the resting length of a muscle is a mechanical treatment. The point may be to assist the healing of that particular muscle from an injury, or to reduce the amount of force encountered by another injured tissue as a result of tightness in that muscle. For instance, we commonly will stretch the hamstrings in order to reduce pain in the knee. If a mechanical problem has led to an inflammatory problem – such as tightness in the shoulder leading to a shoulder bursitis – treating the inflammation may make the problem go away, but do nothing to address the underlying mechanical problem.
Mechanical treatment, on the other hand, can address the underlying mechanical problem, and allow the inflamed area to heal faster, and help to prevent recurrence. Some patients in therapy may end up receiving an anti-inflammatory treatment – like a corticosteroid injection to the shoulder or the back, and most (the smart ones) will come back to therapy and finish their course of treatment. Back to the person that posed the question to me this morning – he will get the injection and his neurosurgeon will ask him to continue his therapy until everything is taken care of to our (therapist, neurosurgeon, patient) satisfaction and we have obtained the best outcome possible.
