Outcomes of Hip Arthroplasty in Sickle Cell Disease: A 20 Year Retrospective Review
Authors: D'Souza Karina , Baptiste Ayanna , Jung Jai , Bellevue Rita 
Published: October 2019

Abstract
Background
Avascular necrosis (AVN) of the hip joints is a common and debilitating complication of sickle cell disease (SCD) of all subtypes. The femoral head of the hip joint is highly susceptible to injury from decreased blood flow. In sickle cell disease, the polymerization of deoxygenated Hemoglobin S leads to decreased deformability and vaso-occlusion in the vascular beds of the bone marrow and periosteum. In some patients, this pathological process is severe, leading to osteonecrosis and collapse of the femoral head and requiring surgical intervention in the form of total hip arthroplasty. Untreated, AVN can lead to the development of chronic pain and frequent hospitalizations. Historically, outcomes for hip arthroplasty have been poor. Furthermore, AVN has been shown to be positively associated with frequency of pain crisis contributing to the economic burden of sickle cell anemia complications on the health care system. One national database estimated post-operative complications during knee or hip replacement among sickle cell anemia patients was 152% higher with up to 42% longer duration of hospitalization when compared to those without sickle cell disease.
Methods
Since 1995, the New York Presbyterian Brooklyn Methodist Hospital center, a community hospital in Brooklyn, New York, has developed a comprehensive health maintenance program for patients with SCD. This program was developed with the goal of providing a central institution to manage the complexities of the sickle cell patient population. Our comprehensive care includes provision of genetic counselling, health maintenance services, screening for complications of sickle cell disease, social work and health education services. We conducted a retrospective descriptive analysis of adult patients with sickle cell anemia who underwent hip arthroplasty between 1996 to 2016. We reviewed lab data, length of hospital stay for hip surgery, use of transfusions and post-operative complications.
Results
Of the 505 adult patients in our database, there were 21 total hip arthroplasties performed on 17 patients - 47% Hemoglobin (Hb) SS, 29% Hb SC, and 24% Hb S/Beta0 thalassemia. The median age at surgery was 41 years (range 22 to 78 years); 65% were female. Baseline hemoglobin in non-SS patients was 10.2 g/dL and in SS patients was 8.5 g/dL. All patients had pre-operative chest X-ray, pulmonary function tests and Echocardiograms. Preoperative transfusion was utilized in 67% of cases. The average length of hospital stay was 8.7 days. There were no episodes of acute chest syndrome after surgery, but 2 patients were re-admitted within 30 days- one with pulmonary embolism and one with abdominal sepsis unrelated to surgery. Two patients suffered venous thromboembolism post-operatively, which was the most common complication in the sample. Two patients were on hydroxyurea at time of surgery- both could not be transfused peri-operatively because of history of delayed transfusion reactions due to red cell alloimmunization. Both patients had hospital stays less than the average stay. All patients received intensive physical therapy and were given incentive spirometers following procedures with frequent follow up in the clinic.
Conclusions
These data demonstrate that through a multi-disciplinary approach to care, perioperative complications following hip arthroplasty occurred less frequently when compared to previous data. Although protocols were in place for post-operative venous thromboembolism prophylaxis, this was the most common complication seen in our study. Given the complexities of Sickle cell disease and the increasing cost associated with this procedure, a comprehensive multi-disciplinary approach to care is the key to positive outcomes in these patients.

Disclosures
No relevant conflicts of interest to declare.