Abnormally High Dislocation Rates of Total Hip Arthroplasty After Spinal Deformity Surgery.
The purpose of this study was to determine the prevalence of concurrent spinopelvic fusion and THA and identify the risk of THA dislocation in patients with concurrent spinopelvic fusion.



We retrospectively reviewed an institutional database of spinal deformity patients and the Humana Inc data set to identify patients with concurrent THA and spinopelvic fusion. The prevalence of concurrent THA and spinopelvic fusion was identified, as was the risk of dislocation for all cohorts.



Of 328 patients with spinopelvic fusions at our institution, 15 patients (4.6%) were found to have concurrent THA. Similarly, within the Humana database among 1049 patients with spinopelvic fusion, 4.6% had a concurrent THA. Among the 58,692 THA patients identified, only 0.1% had a concurrent spinopelvic fusion. A THA dislocation was observed in 3 of 15 patients (20.0%) and 3 of 18 THA (16.7%) within our institutional review. Within the Humana database, 8.3% of patients with THA and spinopelvic fusion went on to have a dislocation of their THA compared to 2.9% of patients with THA and no history of spinopelvic fusion (relative risk: 2.9 [1.2-7.6]).



Among patients with spinopelvic fusion, the prevalence of concurrent THA is 4.6%, and among primary THA patients, the prevalence of concurrent spinopelvic fusion is 0.1%. An alarmingly high THA dislocation rate has been demonstrated among THA patients with concurrent spinopelvic fusion at our institution (20%) and within a large national database (8.3%).
Department of Orthopaedic Surgery and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
Nicholas A
NA
Bedard
Department of Orthopaedic Surgery and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
Christopher T
CT
Martin
Department of Orthopaedic Surgery and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
Sean E
SE
Slaven
Department of Orthopaedic Surgery and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
Andrew J
AJ
Pugely
Department of Orthopaedic Surgery, Duke University Medical Center, Durham, North Carolina.
Sergio A
SA
Mendoza-Lattes
Department of Orthopaedic Surgery and Rehabilitation, University of Iowa Hospitals and Clinics, Iowa City, Iowa.
John J
JJ
Callaghan
D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000706:statistics & numerical data; D005260:Female; D006617:Hip Dislocation / Q000453:epidemiology* / Q000209:etiology*; D006801:Humans; D007484:Iowa / Q000453:epidemiology; D004204:Joint Dislocations; D008297:Male; D008875:Middle Aged; D010384:Pelvic Bones / Q000601:surgery*; D015995:Prevalence; D012189:Retrospective Studies; D013123:Spinal Fusion / Q000009:adverse effects* / Q000706:statistics & numerical data
dislocation; hip; spine; spinopelvic fusion; total hip arthroplasty