Ronald C Huang1, Art L Malkani2, Steven F Harwin3, William J Hozack4, Michael A Mont5, Carlos A Higuera-Rueda6, Geoffrey H Westrich7. 1. Hospital for Special Surgery, Adult Reconstruction and Joint Replacement, New York, NY; Department of Orthopedic Surgery, BronxCare Health Systems, Bronx, NY. 2. Kentucky One Health Orthopedics, Louisville, KY. 3. Department of Orthopedics, Mt. Sinai West Hospital, New York, NY. 4. Rothman Institute, Philadelphia, PA. 5. Department of Orthopedics, Cleveland Clinic, Cleveland, OH; Department of Orthopaedic Surgery, Lenox Hill at Northwell, New York, NY. 6. Department of Orthopedics, Cleveland Clinic, Cleveland, OH. 7. Hospital for Special Surgery, Adult Reconstruction and Joint Replacement, New York, NY.
Abstract
INTRODUCTION: Modular Dual Mobility (MDM) constructs in total hip arthroplasty (THA) offer increased hip stability compared with constrained liners, without compromising hip range of motion. The purpose of this study was to evaluate outcomes of revision THA using MDM. METHODS: The study was a multiinstitutional retrospective cohort study of 315 hips that underwent revision THA using MDM between 2011 and 2017. Clinical outcomes and reasons for failure were collected. RESULTS: Three hundred fifteen patients met 1-year minimum follow-up (mean 3.3 years). Nine hips had instability postoperatively (2.9%), and 30 hips required reoperation (9.5%). Seven had recurrent instability (6.5%) which was associated with liner-only exchange (P = .021) and liner outer diameter of ≤ 38 mm (P = .016). CONCLUSION: Revision THA with MDM provided a low rate of instability and reoperation in a revision cohort. Recurrent instability following use of MDM in revision THA was associated with retention of the acetabular component and polyethylene outer diameter ≤ 38 mm. LEVEL OF EVIDENCE: Therapeutic Level III.
INTRODUCTION: Modular Dual Mobility (MDM) constructs in total hip arthroplasty (THA) offer increased hip stability compared with constrained liners, without compromising hip range of motion. The purpose of this study was to evaluate outcomes of revision THA using MDM. METHODS: The study was a multiinstitutional retrospective cohort study of 315 hips that underwent revision THA using MDM between 2011 and 2017. Clinical outcomes and reasons for failure were collected. RESULTS: Three hundred fifteen patients met 1-year minimum follow-up (mean 3.3 years). Nine hips had instability postoperatively (2.9%), and 30 hips required reoperation (9.5%). Seven had recurrent instability (6.5%) which was associated with liner-only exchange (P = .021) and liner outer diameter of ≤ 38 mm (P = .016). CONCLUSION: Revision THA with MDM provided a low rate of instability and reoperation in a revision cohort. Recurrent instability following use of MDM in revision THA was associated with retention of the acetabular component and polyethylene outer diameter ≤ 38 mm. LEVEL OF EVIDENCE: Therapeutic Level III.