When bones lose their blood supply, they begin to die, and, eventually, collapse, which leads to pain and arthritis. This unfortunate condition is known as osteonecrosis. It can occur in one or several bones of the body, but it is most commonly found in the upper leg. Other sites subject to osteonecrosis are the upper arm, knees, shoulders and ankles. Osteonecrosis can affect men and women of any age, but it usually strikes patients in their 30s, 40s, and 50s.
The early stages of the disease may not produce any symptoms, but as the disease progresses, and as more bone is lost, the patient will suffer from joint pain that becomes more severe as the disease gets progresses. The cause of osteonecrosis is uncertain, but there are particular risk factors that can increase your chances of getting osteonecrosis. These risk factors are: long-term steroid treatments, alcohol abuse, joint injuries, and certain diseases such as arthritis and cancer.
Osteonecrosis ultimately results in the destruction of the joint if left untreated. Even though it can affect any joint, ostoenecrosis is observed most frequently in the hip. Advanced stages require a total hip replacement. If, however, the disease is detected early enough, a procedure called a core decompression can improve the joint. Core decompression consists of drilling a small hole in the diseased bone. Osteonecrosis increases pressure within the diseased bone, and this pressure increase seems to be responsible for the pain associated with osteonecrosis. In some patients, this pain becomes intolerable. Core decompression relieves the pressure in the bone and the drill hole fills with tissue and, in some cases, induces the formation of new bone. Core decompression may also increase the blood flow to the diseased area of bone and allow new blood vessels to form. The procedure appears to slow down the disease process in most cases and may even stop its progression in others.
Can stem cells increase the recovery rate and bone deposition after core decompression? A study from the Postgraduate Institute of Medical Education and Research, Chandigarh, India has used bone marrow stem cells with core decompression to speed the process of recovery.
In this study, 40 patients that had a total of 51 hip joints with osteonecrosis were examined. 25 hip joints were treated with core decompression, and the remaining 26 hips received core decompression plus the insertion of bone marrow stem cells from their own bone marrow into the hole that had been drilled in their hip bones (femurs).
Patients from these two groups were compared in several ways. First, the hips were imaged by X-rays and MRIs 12-24 months after the procedure. Patients were also given a detailed questionnaire that ascertained their activity level, degree of motion and pain (Harris Hip score). Finally, the survival of the hip-joint was measured in groups (Kaplan-Meier hip survival analysis). If the hip failed to survive and required a total hip replacement, then the treatment did not sufficiently slow the progression of the disease.
1-2 years after the procedure, patients in the group that had received the bone marrow stem cells inserted into the drilled hole had significantly better clinical results than the group that had only received core decompression. These patients had less pain, a greater range of motion and better activity levels. Also, the rate of hip survival was greater in the group that had received bone marrow stem cells. Finally, those patients that were in the worse shape upon entering the study were consistently in better shape if they were in the group that had received the stem cells.
Therefore, this simple procedure – inserting bone marrow stem cells into the drill tract after core decompression – seems to lead to better clinical outcomes than just core decompression. Hopefully larger clinical trials will confirm the efficacy of this procedure and might even make it a standard procedure that accompanies core decompression.
See Sen RK, Tripathy SK, Aggarwal S, Marwaha N, Sharma RR, Khandelwal N. Early results of core decompression and autologous bone marrow mononuclear cells instillation in femoral head osteonecrosis: a randomized control study. J Arthroplasty 2012 27(5):679-86. doi: 10.1016/j.arth.2011.08.008.