Medical Exhibits - Demonstrative Evidence Expert Blog - MediVisuals

By: Robert Shepherd MS, Certified Medical Illustrator, Vice President and Director of Eastern Region Operations, MediVisuals Incorporated

Intra-articular fractures are simply fractures that involve a joint space (see below figure). While intra-articular fractures appear very similar to those that do not involve a joint space (extra-articular fractures), intra-articular fractures are significantly more serious because they are associated with a much greater incidence of long-term complications.

In order to appreciate why intra-articular fractures can be so problematic, a fundamental understanding of a typical joint is helpful. The following images show a knee joint. With the exception of a meniscus, almost all moveable joints are similar to the knee joint in that the joints are lined with a thick, shock-absorbing articular cartilage adherent to smooth, bony surfaces that allow pain-free movement.




When a fracture involves the articular surface of one or more bones of a joint, the articular cartilage and smooth articular surface of the bone are disrupted. In order for joints to have the best chance of proper joint function after healing, physicians go to greater effort to make sure the bony surfaces are properly aligned and that the joint is properly immobilized than they would with a similar fracture that is extra-articular. Even with the best fracture alignment and joint immobilization, subtle disturbances in the joint surface and the natural bone reformation that take place during healing can result in uneven joint surfaces and injury to the overlying articular cartilage (see the below illustration). Because of the abnormalities of the injured and healed joint surface, natural movement of the joint can also damage the articular cartilage of the opposing joint surface. Over the course of time, these injuries self-perpetuate and may necessitate arthroscopic debridement, chondroplasty or even joint replacement.

It is also important to realize that a fracture needs not enter a joint to result in injury to the articular surfaces and begin the self-perpetuating post-traumatic breakdown of the joint surfaces (post-traumatic arthritis). As shown in the below illustrations, joint trauma without a diagnosable fracture of any type can injure the smooth, shock-absorbing articular cartilage, with or without microfractures of the underlying bone. This can result in partial or total loss of the articular cartilage and in uneven "bone-on-bone" articulation that severely decrease range of motion and result in debilitating joint pain.

By: Robert Shepherd MS, Certified Medical Illustrator, Vice President and Director of Eastern Region Operations, MediVisuals Incorporated

On occasion, it is uncertain exactly which intervertebral disc may be causing a plaintiff’s pain.  Physicians may conduct a discography study prior to surgery in these cases.

This procedure involves advancing needles into the discs in question and injecting contrast material that serves two purposes:  (1) The contrast material makes it possible to better analyze the exact defects (if any) in the discs when X-rays or CTs are taken after the administration of the contrast material. (2) The contrast material also increases the pressure within the disc causing it to expand and subsequently compress the nearby nerve roots.  If     the pain corresponds to the patient’s normal pain, then that disc is determined as the     “problem disc”.

When pain is thought to be associated with irritation or inflammation of the nerve root(s) or surrounding tissues, epidural injections can be performed. As shown in the animation below, epidural injections involve administering anesthetics and steroids around the nerve root(s).  These injections can be used as a diagnostic tool as well as a treatment.

If the epidural injections are ineffective, the cause of the pain may not be related to the nerve root(s).  If the injections are effective, it confirms the nerve root(s) as the source of the pain. Repeated treatments may resolve the pain; if not, more aggressive treatments may be necessary.

Sometimes the facet joints themselves can be the source of pain. One of the terms used to refer to this condition is “facet arthropathy”.  This condition results from the breakdown of the normal, healthy joint spaces. With the breakdown of these articular surfaces, the joints become painful with each movement.

Each facet joint is supplied by a small dorsal branch of the adjacent nerve root [see illustration below].  Injections in or around the facet can again serve to determine the painful facet(s) and help resolve the pain.

If facet joint injections are unsuccessful at resolving the pain, the nerves to the facets can be destroyed by a procedure known as ablation. Ablation involves advancing a needle adjacent to the facet nerve and destroying it, thereby eliminating the pain.