I had some special enzyme injections into the palm of my hand to help me straighten my fingers. It worked great for the main joints (my knuckles aren't so bent up) but not for the middle joint. How come? Is this what happens to other people or just me?
It sounds like you have been treated with collagenase enzymatic injection for Dupuytren's contracture. This type of hand problem is a fairly common disorder of the fingers. The condition usually shows up as a thick nodule (knob) or a short cord in the palm of the hand, just below the ring finger. More nodules form, and the tissues thicken and shorten until the finger cannot be fully straightened. Dupuytren's contracture usually affects only the ring and little fingers. The contracture spreads to the joints of the finger, which can become permanently immobilized. The areas affected most often are the metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints. Flexion contractures usually develop at the metacarpophalangeal (MCP) joints first. The MCP joints are what we usually refer to as the "knuckles." As the disease spreads from the palm down to the fingers, the proximal interphalangeal (PIP) joints start to be affected as well. The PIP joints are the middle joints you mentioned. The development of this less invasive method of treatment called enzymatic fasciotomy is being used with mild to moderate cases. By injecting an enzyme directly into the cords formed by the disease, the tissue dissolves and starts to weaken. Then the patient can stretch the fingers and break apart the cord himself/herself. Many (but not all) patients are able to avoid surgery with this treatment. Early studies showed a good success rate in reducing MCP contractures using this injection treatment. Almost everyone treated this way was able to straighten the MCP joints with less than a 30-degree flexion contracture. Results were not quite as good for the PIP joints. Less than half of the patients with PIP contractures had regained full motion of the affected joint. A recent study involving 37 surgeons around the world and 1,080 joints treated with collagenase injection has given us some good feedback. The long-term results (after three to five years) measured by recurrence rates with enzyme fasciotomy were not quite as good as responses in the short-term. For example, one-third of the MCP joints and two-thirds of the PIP joints that were corrected had a recurrence. And of the joints that were only partially corrected in the first study, half had a worsening in the years to follow. Recurrence was defined as a 20-degree (or more) flexion contracture (finger won't straighten and remains flexed by at least 20-degrees). These are fingers that were able to straighten within five degrees of normal after the injection. Adverse effects of this injection treatment for Dupuytren's contracture are minimal and in the long-term, nothing worse than recurrence occurs. This was true even when up to eight injections were used and bloodworm showed antibodies in response to the collagenase. No systemic allergic reactions occurred. The authors concluded that the treatment is safe and effective for mildly involved joints. Their study will continue on and collect further long-term information. The treatment is certainly worth a try if it can prevent patients from having surgery. Results are not as good with PIP joints but you still have the option of a series of repeat injections (or even surgery if that fails).