Relative frequency of primary total hip arthroplasty for avascular necrosis in the United States as compared to a regional center: A data review

Abstract

Background: The relative frequencies of indications for primary total hip arthroplasty (THA) are not well-established. This study aims to establish the incidence of THA performed for Avascular Necrosis of the hip (AVN), as well as the other most common indications for THA in the United States, as compared to the incidences at a high-volume tertiary referral center in Miami, Florida. We hypothesize that the relative incidence of AVN and each other indication for THA will vary significantly between the United States as a whole and the tertiary referral center.

Methods: A query of the 2016-2017 National Inpatient Sample (NIS) and a tertiary referral center adult reconstruction registry was completed. The relative frequencies of each indication for THA, demographics, and behavioral risk factors were analyzed.

Results: 225,061 primary THA patients in the National Inpatient Sample database and 447 in the Miami tertiary referral center database were included in the final analysis. The proportion of primary THA for AVN in the NIS database (5.97%) was significantly lower than the same proportion in the tertiary referral center database (22.2%), p < .001. There was no significant difference in the incidence of primary THA for osteoarthritis, inflammatory arthritis, or hip dysplasia between the two populations.

Conclusion: The incidence of THA for AVN is significantly different between a tertiary referral center and the greater United States. Patient demographics, race, and behavioral risk factors are associated with the disparity. Orthopaedic surgeons should recognize the differences in THA indication between populations when counseling patients on treatments, outcomes, and the most current literature.

Keywords: AVN Total hip arthroplasty; Avascular necrosis; Indications; National inpatient sample; OA; Osteoarthritis.

Fig. 1

Flowchart of data collection in the National Inpatient Sample Data on 14,294,784 from the 2016–2017 NIS database was reviewed. A final THA cohort used in analysis included 225,061 patients. “Pre-determined” diagnoses included avascular necrosis of the hip, osteoarthritis of the hip, rheumatoid arthritis, hip dysplasia, femoral head/neck fracture, ankylosing spondylitis, and pathological fracture. Patients with a THA code and either a pre-determined diagnosis or no periprosthetic fracture or osteolysis diagnosis were the patients used in the final analysis.

Fig. 2

Total Diagnoses Among Total Hip Arthroplasty Patients, National Inpatient Sample Database 2016-17 Osteoarthritis of the hip (OA) was the most common indication for surgery for Total Hip Arthroplasty (THA) patients in the NIS database from 2016 to 17. Other diagnoses considered were Femoral Head/Neck Fracture (FHNFx), Avascular Necrosis of the hip (AVN), Inflammatory Arthritis (IA), Hip Dysplasia (HD), and Other (Oth).

Fig. 3

Total Diagnoses Among Total Hip Arthroplasty Patients, Miami Tertiary Referral Center Osteoarthritis of the hip (OA) was the most common indication for surgery for Total Hip Arthroplasty (THA) patients in the Miami tertiary referral center. Other diagnoses considered were Avascular Necrosis of the hip (AVN), Inflammatory Arthritis (IA), Hip Dysplasia (HD), Femoral Head/Neck Fracture (FHNFx), and Other (Oth).