FORT LAUDERDALE, FLA. – Hip joint pain and deterioration can be a painful and disabling outcome for patients with sickle cell disease, but femoral head core decompression with the addition of bone marrow aspirate concentrate decreases their pain and may help avoid or delay hip replacement, according to results of a pilot study presented at the annual meeting of the Foundation for Sickle Cell Disease Research.
Eric Fornari, MD, of the Children’s Hospital at Montefiore in Bronx, N.Y., reported on results of core decompression (CD) in 35 hips of 26 sickle cell patients; 17 underwent CD only and 18 had CD with injection of bone marrow aspirate concentrate (CD+BMAC). The average patient age was 24.3 years, with a range from 9.7-50.7 years.
“Compared to patients treated with CD alone, patients treated with CD+BMAC complained of significantly less pain and had significant improvement in their functional scores and patient-related outcomes at short-term follow-up,” Dr. Fornari said.
Among the CD+BMAC patients, pain scores declined two points on average, from 6 preoperatively to 4 postoperatively, he said. This was clinically significant, compared with the CD-only group, Dr. Fornari said.
Patients in the CD+BMAC group also reported consistently superior hip outcome and modified Harris hip scores. With either treatment, more than 90% of patients were pain-free and walked independently at their most recent follow-up, he said.
The objective of CD is to relieve pressure within the head of the femur, stimulate vascularity and target the avascular necrosis (AVN) lesion within the head that is visible on imaging. To get the bone marrow aspirate concentrate, Dr. Fornari extracts 120 cc of bone marrow from the iliac crest, then concentrates it to 12 cc. The same instrument is used to tap into the femoral head and inject the bone marrow aspirate concentrate. The study looked at clinical and radiographic outcomes of treated patients.
Average follow-up for the entire study population was 3.6 years, but that varied widely between the two groups (CD-only at almost 6 years, CD+BMAC at 1.4 years) because CD+BMAC has only been done for the last 3 years, Dr. Fornari said.
Progression to total hip arthroplasty (THA) was similar between both groups: 5 of 17 patients (29%) for CD-only vs. 4 of 18 patients (22%) for CD+BMAC (P = .711).
“When you look at progression, there were a number of hips that got CD or CD+BMAC and were better postoperatively; they went from a Ficat score of stage II to a stage I, or stage III to stage II,” he said.
X-rays were not always a reliable marker of outcome after either CD procedure, Dr. Fornari noted. “I’ve seen patients who’ve had terrible looking X-rays who have no pain, and patients who have totally normal X-rays that are completely debilitated,” he said. “We have to start asking ourselves, ‘What is the marker of success?’ because when we do this patients are feeling better.”
Multivariate analysis was used to identify factors predictive of progression to THA after the procedure, Dr. Fornari said. “Age of diagnosis, age of surgery, female gender, and lower hydroxyurea dose at surgery were predictive of advancing disease, whereas a higher dose of hydroxyurea was predictive against advancement,” he said.
The average age of patients who had no THA after either procedure was 21 years, compared with 33.9 years for those who had THA (P = .003). Average hydroxyurea dose at surgery was 24.7 mg/kg in the no-THA group vs. 12.5 mg/kg in those who had THA (P = .005).
Notably, there were no readmissions, fractures, deep vein thromboses, pulmonary embolisms or infarctions after CD, Dr. Fornari said. Transfusions were required in two CD-only and three CD+BMAC patients. Hospitalization rates for vaso-occlusive crisis were similar between groups (P = .103).
Dr. Fornari said the challenge is to identify suitable patients for these procedures. “These are complicated patients and you don’t want to put them through the process of having surgery, putting them on crutches and restricted weight bearing, if they’re not going to get better,” he said. “This procedure done minimally invasively is not the end all and be all, but we have to figure out who are the right patients for it. Patient selection is key.”
Finding those patients starts with a rigorous history and physical exam, he said. Physicians should have a “low threshold” for MRI in these patients because that will reveal findings, such as pre-collapse disease and characteristic of AVN lesions, that may appear normal on X-ray. Patient education is also important. “To think that an injection into the top of the hip is going to solve all their problems is a little naive, so you have to have an honest conversation with the patient,” he said.
Dr. Fornari reported having no financial disclosures.
SOURCE: Fornari ED et al. FSCDR 2019, Abstract JSCDH-D-19-00004.