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Outcomes of primary total hip arthroplasty using dual mobility cups across body mass index categories: a
Chahine Assi1,2, Anthony ElAlam1,2, Joseph Mouawad1,2
1University Medical Center Rizk Hospital, Beirut, Lebanon.
Insights
Dual mobility cups (DMC) in total hip arthroplasty (THA) show comparable outcomes for obese and non-obese patients. This study highlights DMC
Area of Science:
- Orthopedic Surgery
- Biomedical Engineering
- Clinical Outcomes Research
Background:
- Total hip arthroplasty (THA) in obese patients presents higher complication risks.
- Dual mobility cups (DMC) are recognized for reducing dislocation in high-risk THA populations.
Purpose of the Study:
- To evaluate the functional and radiological outcomes of DMC in total hip arthroplasty (THA) across different BMI categories.
- To compare complication rates associated with DMC use in healthy, overweight, and obese patients undergoing THA.
Main Methods:
- Retrospective, multi-center study of 419 patients undergoing primary THA with DMC.
- Patients categorized into healthy, overweight, and obese BMI groups.
- Clinical evaluation using modified Hip Harris Score (mHHS) and radiological assessment; post-operative complications were recorded.
Main Results:
- No significant difference in mean mHHS scores across BMI groups (p=0.2).
- Low rates of dislocation (3 cases, unrelated to surgery) and no intraprosthetic dislocations observed.
- Complication rates, including septic complications and peri-prosthetic fractures, were comparable across BMI groups.
Conclusions:
- Contemporary dual mobility cups (DMC) demonstrate excellent functional and radiological outcomes in obese patients undergoing THA.
- Complication rates with DMC in obese patients appear comparable to non-obese populations.
- Further comparative studies with conventional cups are warranted to validate these findings.
Introduction:
Performing a total hip arthroplasty (THA) in obese patients is known to be associated with an elevated rate of complications. The use of dual mobility cups (DMC) has already been proven for decreasing dislocation episodes in high-risk populations. This is an observational cohort study evaluating the functional and radiological outcomes of DMC across BMI categories namely healthy, overweight and obese populations.
Methodology:
This is a retrospective multi-centric study of 419 patients who underwent a primary THA with a DMC (THA-DMC) from 2006 to 2022. The patients were divided in three groups according to their BMI and were evaluated clinically with the modified Hip Harris Score (mHHS) and radiologically. Post-operative complications were recorded during the follow-up period.
Results:
The mean age of the included patients was 70 ± 13.19 years (p = 0.006). The mean follow-up period was nine ± 6.2 years. At final follow-up, the mean modified HHS score was 85.56 ± 6.09 in the normal weight subgroup vs 92.39 ± 4.89 in the overweight subgroup and 89.24 ± 4.40 in the obese subgroup (p = 0.2). Three patients, one in the overweight and two in the obese subgroups, had a traumatic dislocation unrelated to the surgery. No cases of intraprosthetic dislocations were observed. Two patients in the obesity subgroup required additional surgeries for septic complication. The radiological assessment revealed no signs of migration or tilting of the components. Osteolysis was detected in 4 cases with non-progressive lines and no symptoms at last follow up. Heterotopic ossifications were observed in 15 asymptomatic patients. Three patients had a traumatic peri-prosthetic fracture.
Discussion:
The use of a contemporary dual mobility cup in obese patients seems to yield excellent functional and radiological outcomes with a complication rate comparable to that of a non-obese population. Comparative studies with conventional cups are needed to confirm or infirm our results.
