Diagnosis and Treatment of Hand Infections
In this article, hand surgeons from the Walter Reed National Military Medical Center in Washington, D.C. offer us a review of rare, but potentially disabling hand infections. They focus on two infections of the wrist, hand, or fingers: osteomyelitis and septic arthritis. Causes, type of bacteria involved, patient symptoms, diagnosis, and treatment are summarized for each condition. Complications with and without treatment are also presented.

Osteomyelitis is an infection of the bone or bone marrow that can affect the hand. The most common infecting bacteria are staph, strep, and e coli. Undiagnosed, delayed diagnosis, or untreated, any of these infectious agents can cause destruction of the joint. Loss of motion, impaired function, and eventual arthritis with pain, stiffness, and disability can occur. The disease process can get so bad, a person can lose the affected hand.

How does a person get osteomyelitis of the hand or wrist? There are three main mechanisms: 1) puncture wounds (e.g., human bites, thorns, fractures, and surgery), 2) spread from infection of nearby soft tissues, and 3) spread through the blood system from any other infection in the body.

The immune system sets up an inflammatory response and tries to wall off the infection. In the healthy child or adult, this reaction may be enough to take care of the problem. But malnutrition, smoking, medications that suppress the immune system, and cancer or other health problems can put the patient at a disadvantage for self-healing.

In the case of one particular bacteria (methicillin resistant Staphylococcus aureus or MRSA, pronounced "mersa"), even healthy people can be affected. Tissue invasion and severe bone destruction can occur quickly. That's why early diagnosis and immediate treatment is recommended for hand infections of this type.

How does the hand surgeon know a patient has an osteomyelitis-linked hand infection? There are usually visual signs (swelling, redness, warmth) and pain. The patient may have a fever with chills and fatigue. These flu-like symptoms are a red flag of systemic (system-wide) infection. Blood tests and imaging studies possibly including X-rays, bone scans, PET scans, MRIs, and other more advanced imaging aid in making the diagnosis.

Once it's clear what the surgeon is dealing with, then treatment begins. Antibiotics may be all that's needed if the problem is identified and caught early. But most of the time, surgery is needed to debride (clean out) the area. This surgical procedure is followed by a course of antibiotics as well.

It may be necessary to perform more than one debridement, a process called serial debridement. Serial debridement is done until the affected area is clear of infection. The whole process can take six weeks or more. If the infection has occurred around an implant (e.g., joint replacement or hardware used to repair a fracture), the implant may have to be removed before debridement and antibiotics can be successful.

Even with successful treatment of osteomyelitis, there can be long-term results of the disease process. For one thing, the infection can come back. Pain and stiffness may persist for months to years. Deformity from bone destruction and fractures can result in loss of hand strength and function.

Infection that never goes away fully can eventually become cancerous. As mentioned, amputation may be required for chronic, unresolved cases. In fact, half of all fingers with osteomyelitis end up being amputated. So you can see why early diagnosis and intervention are extremely important with osteomyelitis of the wrist, hand, and fingers.

Now, what about septic arthritis, the second point of focus of this article? The difference between osteomyelitis and septic arthritis is location. Remember, osteomyelitis is a bacterial infection of the bone or bone marrow. Septic arthritis is an overgrowth of the same bacteria only in the joint instead of in the bone.

Causes of septic arthritis of the wrist and hand are similar to osteomyelitis of the same areas: trauma (knife wound, human bites, or face punch with puncture by the teeth) and spread from some other nearby location. Staph infections are the most common cause of septic arthritis but joint infections can also be caused by a bacteria called pseudomonas.

Patient factors that increase the risk of septic arthritis include: rheumatoid arthritis, alcohol abuse, diabetes, steroid therapy, injection drug abuse, and chronic kidney or liver failure. As with osteomyelitis, when the immune system gets word that there is a bacterial infection of the joint, it launches an immediate anti-inflammatory response. If unsuccessful, septic arthritis can eat its way through the joint to the bone then causing osteomyelitis (of the bone next to the septic joint).

How can such extreme complications be avoided? You should seek medical help right away after any type of trauma that results in joint pain, swelling, redness, fever, chills, or other systemic (flu-like) symptoms. Lab values, X-rays and other imaging studies, and examination of the joint fluid help the physician make an accurate diagnosis.

Even with early detection, septic arthritis is considered a surgical emergency. It is not treated first with antibiotics. Intravenous antibiotics will be part of the treatment after surgery. The joint is surgically debrided and irrigated (washed out repeatedly). Any area of dead tissue, abscess, or pus is removed. This type of surgery does involve cutting into the cartilage surrounding the joint to gain access to the inside of the joint. The surgeon must be careful to avoid cutting nearby nerves and blood vessels.

The authors conclude by saying that the effects of osteomyelitis and septic arthritis of the wrist, hand, or fingers can be severe. Even with treatment, stiffness and loss of motion can lead to significant disability. Chronic, unresolved infection may result in bone (osteomyelitis) or joint (septic arthritis) destruction requiring amputation.

The best chance for recovery and salvage of the hand is with early diagnosis and treatment. But even when caught quickly, there is still a risk of poor outcomes, especially for patients who abuse tobacco and/or alcohol. Likewise, patients with other health problems are at increased risk for long-term problems. Patients must be advised of these possible complications right from the start to avoid an unhappy surprise if/when treatment is not as successful as hoped for.
Patricia McKay, MD, MC, USN, et al. Osteomyelitis and Septic Arthritis of the Hand and Wrist. In Current Orthopaedic Practice. November/December 2010. Vol. 21. No. 6. Pp. 542-550.