Retrospective Analysis of Core Decompression in Avascular Necrosis of the Femoral Head in Patients with Sickle Cell Disease.
Authors: Cail Austin , Natrajan Kavita , Barrett Nadine , Bowman Latanya , Clair Betsy , Sayer Gloria , Isales Carlos , Corpe Raymond Scott , Kutlar Abdullah 
Published: October 2019

Abstract
Abstract 2108
Avascular necrosis (AVN) of the femoral head is a common complication of sickle cell disease (SCD) and is estimated to occur in approximately 50% of patients with SCD by age 35. AVN is associated with significant morbidity including debilitating pain and disability. Total hip replacement (THR) is a common intervention for AVN; however, complications of hip replacement such as infections, bone fractures, prolonged healing times, and the need for subsequent revisions begs for an alternate intervention in the young SCD patient population. Core decompression is one such intervention but there has not been a common consensus on its efficacy and few studies have analyzed its role in SCD associated AVN. Our retrospective study analyzes the long term outcomes of core decompression in SCD patients.
Records of 100 patients with AVN followed at the Adult Sickle Cell Clinic at Georgia Health Sciences University were reviewed. Twenty-three patients (30 hips) had core decompression (13 female, 10 male). Of these, 21 were Hb SS, 1 was Hb Sβ+ Thalassemia, and 1 was Sβ° Thalassemia. Patient demographics, age at diagnosis, Ficat stage at diagnosis, age at core, Ficat stage at core, symptom relief, THR, time to THR, and duration of follow up were recorded. The age of the patients at the time of the coring procedure ranged from 18–42 years, with a mean age (±SD) of 26.2 ±6.6. Patients had a mean (±SD) follow up period of 10.0±7.2 years after the core decompression.
At the time of coring, 6 hips were stage I (x-ray normal, MRI abnormal), 20 hips were stage II (sclerosis and lytic areas on x-ray), 3 hips were stage III (femoral head flattening and crescent sign), and 1 hip did not have data available. 23/29 (79%) hips had symptom relief. Of these, 5/6 stage I, 16/19 stage II (1 hip was only 1 month post-op so was not included), 1/3 stage III, and 1/1 for the hip without the stage information available. Two of these hips that had symptom relief did eventually have THR (71 and 157 months after core). Five of these hips underwent re-coring procedures (4, 6, 6, 7, and 13 years after 1st core) and none of these went on to THR. Of the 6/29 hips that had no relief from the core, 4 went on to THR (range 5–20 months, mean=11.5± 7.2 months median=10.5 months) and 2 have been advised of the need for THR and/or are currently considering it (both currently stage IV). Including the 2 hips that were determined to be successful in relieving symptoms that had THR, there were 6/29 hips that had THR, and the time to THR ranged from 5–157 months, mean=45.7±59.8 months, median= 17.5 months.
Our data suggests that core decompression is a practical option for SCD patients with early stage AVN of the femoral head. If our results pan out across multiple Sickle Cell Centers, core decompression can provide significant pain relief and delay the need of THR greatly reducing morbidity from chronic pain and improving functional outcomes. Our data, however, are contrary to the results of a multi-center study of core decompression which compared physical therapy and core decompression to physical therapy alone in 35 patients with SCD in which the follow-up period was only three years. In contrast, the strength of our study is the mean follow-up of ten years. Age range of patients from our study did not differ from that of the multicenter study. Data collection on a larger number of patients from multiple centers, perhaps in the form of a registry or a randomized trial with adequate number of patients to answer the question of the value of core decompression in SCD might be informative in this regard.

Disclosures:
No relevant conflicts of interest to declare.