You never really know or appreciate just what one little finger joint can do for you -- until you lose the ability to move it. But patients with osteoarthritis of the interphalangeal (IP) joint can testify that pain limits function and even movement of the other finger joints.
It is possible to replace damaged joints these days -- even finger joints like the interphalangeal (IP) joint. That's the middle finger joint between the large knuckle and the tip of the finger. But does replacing the degenerated IP joint restore normal motion and function?
Early reports after interphalangeal (IP) joint replacements said, 'Yes! Good results!" But the authors of this report suggest differently. One surgeon replaced 31 IP joints in the hands of 17 patients and then followed them for at least two years. Most were followed for an average of four years (or more).
Results were measured using pain, finger joint motion, finger and hand function, and X-ray findings. X-rays were used to look at alignment of the implants including subsidence (sinking of the implant down into the bone) and implant failure (fracture, dislocation). Activities of daily living and patient satisfaction were also assessed as important outcome measures.
What they found was that like the results reported from other studies, in the early months, patients experienced significant improvements in pain, motion, and function. But over time, significant problems developed.
Pain persisted. Complications occurred that required additional surgeries. For example, there were five joint dislocations, one fracture, and 11 complaints of finger squeaking. Some joints just wouldn't move at all while in others the implant loosened creating an unstable joint. In quite a few cases, the implant shifted and moved until it had migrated right out of the bone!
The surgeon performing the study attributed these complications to the particular type of implant he was using (a pyrolytic carbon resurfacing joint replacement). When he tallied up all the problems and saw how unhappy his patients were with the results, he stopped using this particular type of implant.
The material (pyrolytic carbon) is supposed to wear well and last a long time. It has the added advantage of stimulating bone growth, which is important to help the body create a stable implantation. But as the results of this study show, the benefits didn't last.
With 60 complications in 28 joints, a different strategy is needed. The need for good finger pinch and grip strength in everyday activities is just too important. Good short-term results aren't enough if long-term results aren't as good if not better.
In this study group, the patients who received the pyrolytic carbon resurfacing interphalangeal implant either had a revision surgery with a different type of implant (silicone) put in place or they had the joint fused.
Fusion of the IP joint is unfortunate because the result is often the inability to pick up and/or handle small objects. Try going a day without being able to do that and you'll appreciate how disabling it can be to lose IP motion and function.
The authors hope the pyrolytic carbon implant will be improved upon and yield better results in the future. The results of this long-term study may assist in showing the manufacturers of the device just what the problems are and how to address them.
Reference: Thomas M. Sweets, MBA, MD, and Peter J. Stern, MD. Pyrolytic Carbon Resurfacing Arthroplasty for Osteoarthritis of the Proximal Interphalangeal Joint of the Finger. In The Journal of Bone and Joint Surgery. August 3, 2011. Vol. 93-A. No. 15. Pp. 1417-1425.