Analysis to Predict THA Dislocation with Different Factors
There are several risk factors for dislocation after THA, but few studies include radiographic assessment of implants, with spine pathology and patient characteristics. This study estimates the rate of dislocation by patient sex, age, race/ethnicity, BMI, Charlson Comorbidity Index, spine pathology, prior spine fusion, levels affected, radiographic Kellgren-Lawrence score of spine osteoarthritis, THA indication, surgical approach, and femoral head size.

76 primary THA patients with a dislocation were matched on age and sex to subjects without a known history of dislocation using a 2:1 allocation. Univariable and multivariable survival models that account for matched strata were used to estimate the rate of dislocation.

--Follow-up of patients at-risk for dislocation was 26.48 months.

--On multivariable analysis, patients with an indication other than primary osteoarthritis were 3.69 times more likely to dislocate than those with osteoarthritis.

--Patients with a spine pathology were also nominally more likely to dislocate and patients receiving a posterior surgical approach were 2.74 times more likely than those receiving a non-posterior approach to dislocate.

Conclusively, patients who had THA for reasons other than primary osteoarthritis and were treated with a posterior surgical approach, as well as spinal pathology to a lesser extent, were shown to have a higher rate of dislocation.