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How Does Conversion Total Hip Arthroplasty Compare to Primary?
Scott J Douglas1, Ethan A Remily1, Oliver C Sax1
1Rubin Institute for Advanced Orthopedics, Center for Joint Preservation and Replacement, Sinai Hospital, Baltimore, MD.
Insights
Conversion total hip arthroplasty (THA) leads to more complications, higher readmission rates, and increased costs compared to primary THA. This highlights the need for separate reimbursement classifications for conversion THA procedures.
Area of Science:
- Orthopedic Surgery
- Health Economics
- Medical Data Analysis
Background:
- Institutional data indicates conversion total hip arthroplasty (THA) has higher complication rates and costs than primary THA.
- Current reimbursement systems group conversion and primary THAs under the same diagnosis-related group, despite differing outcomes.
Purpose of the Study:
- To compare complication rates, 30-day readmission rates, and 90-day costs between conversion THA and matched primary THA patients.
- To provide evidence for reclassifying conversion THA into a distinct diagnosis-related group.
Main Methods:
- Retrospective review of the PearlDiver database (2010-2018).
- Comparison of conversion THA (CPT 27132) and primary THA (CPT 27130) using matched patient data (n=8369 conversion, n=25,081 primary).
- Matching criteria included age, gender, Charlson Comorbidity Index, BMI, tobacco use, and diabetes.
Main Results:
- Conversion THA showed significantly higher rates of periprosthetic joint infections (7.7% vs 1.4%), dislocations (4.5% vs 2.0%), blood transfusions (2.0% vs 1.0%), mechanical complications (5.5% vs 1.0%), and revision surgeries (4.0% vs 1.5%) within 90 days.
- The 30-day readmission rate was higher for conversion THA (7.3% vs 3.3%).
- Median 90-day costs were significantly higher for conversion THA ($18,800 vs $13,611).
Conclusions:
- Conversion THA is associated with increased complications, revisions, readmissions, and costs compared to primary THA.
- The findings support the reclassification of conversion THA into a separate diagnosis-related group from primary THA to reflect its distinct risk and cost profile.
Background:
Recent institutional evidence suggests that conversion total hip arthroplasty (THA) incurs higher complication rates and costs when compared to primary THA. These findings contrast with the current reimbursement system as conversion and primary THAs are classified under the same diagnosis-related group. Thus, a national all-payer database was utilized to compare complication rates up to 2 years, 30-day readmission rates, and 90-day costs between conversion THA and matched primary THA patients.
Methods:
A retrospective review of the PearlDiver database between 2010 and second quarter of 2018 was performed using Current Procedural Terminology (CPT) codes to compare conversion THA (CPT 27132) to primary THA (CPT 27130). Patients were matched at a 1:3 ratio based on age, gender, Charlson Comorbidity Index, body mass index, tobacco use, and diabetes (conversion = 8369; primary = 25,081 patients).
Results:
Conversion THA had higher rates of periprosthetic joint infections (conversion: 7.7% vs primary: 1.4%), hip dislocations (4.5% vs 2.0%), blood transfusions (2.0% vs 1.0%), mechanical complications (5.5% vs 1.0%), and revision surgeries (4.0% vs 1.5%) (P < .001 for all) by 90 days. The 30-day readmission rate for conversion THA was significantly higher compared to the primary group (7.3% vs 3.3%) (P < .001). Median cost at 90 days for conversion THA was significantly higher compared to primary THA ($18,800 vs $13,611, P < .001).
Conclusion:
This study revealed increased complication rates, revisions, readmissions, and costs among conversion THA patients compared to matched primary THA patients. These results support the reclassification of conversion into a diagnosis-related group separate from primary THA.
