Facet Joint Injuries
When you view a spine model from behind, you will notice that on each spinal level, there are two small joints, called facet joints. The interesting fact about these joints is that they look and act the same as a knee joint.
Facet joints have cartilage between the two bony surfaces. Around the joint there is a capsule, which is reinforced with small ligaments. Inside the joint there is fluid, called synovial fluid, similar to the oil in a car's engine.
Facet joints are designed to move. It is important to know that for a facet joint to stay healthy, it needs movement. When movement decreases due to injury or disease, it causes the ligaments and capsule to shrink and the fluid becomes less inside in the joint. This leads to increased degenerative changes to the cartilage in the joints, which cannot be reversed.
Facet joints often get injured through two common, yet distinct processes- sprain and strain:
Similar to an ankle sprain, facet joints are designed to move, but often cannot tolerate sudden movement (sprain). Facet joints in the lumbar spine often undergo sprain through sudden slips, sports injury or car accidents. Similar to an ankle, the joints will swell, become hot and inflamed, and decrease it's movement. It's also important to know the facet joints in the spine also have a close relationship with the adjacent muscles. When facet joints get injured, muscles guarding/spasm is quite common. The good news is that facet joints, like ankle sprains, heal. For the joint to heal, movement (therapy) is essential. Cartilage works like a sponge. It has no blood supply and movement helps provide adequate nutrition to the joint structures to heal. When cartilage is compressed (loaded), fluid is forced out of the facet joint, and when the pressure is taken off, fluid enters the cartilage again. This process will help the facet joint "heal to the best of it's ability." As the joint heals, local muscle guarding and spasm should decrease.
Strain is a process where load is applied to a structure for a period of time. In this case, facet joints would undergo loading for a prolonged period of time. Facet joints tend to load extensively when the spine is extended; for example, standing, working overhead or carrying a heavy backpack. Since the joints are in constant load, fluid is forced out of the cartilage, which over prolonged periods of time will cause degenerative changes and damage to the cartilage. With less fluid in the joint, the body structures will load more. This will lead to the body deposition more bone in the area (sclerosis), which causes the degeneration of the joints. The degenerative changes cause the cartilage to deteriorate, ligaments and capsules shrink, causing more compression, and so the cycle continues.
Once again, MOVEMENT IS ESSENTIAL.
Rehab: A therapist will carefully design/choose exercises to enhance movement of these facet joints to facilitate the healing process. Since exercise is not specific to one level of the spine (example- injured level), they often utilize techniques such as spinal mobilization and/or spinal manipulation. These techniques are designed to create movement "one level at a time," and in conjunction with exercise and advice, are very beneficial in helping facet joints heal.
Facet joint healing: Ankle sprains often heal in a few (3-4) weeks. Facet joints heal a little slower- mainly due to the limited blood supply, so be patient. Also- remember that there are lots more nerve supply around the spinal column, so facet joints may stay "sensitive" for a while. This is normal.
*For more information- ask your physical therapist. This is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.
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