INTRODUCTION: 

Prosthetic joint infection and aseptic osteolysis can result in severe bone and soft tissue deficits1,2. In revision hip arthroplasty, bone defects about the acetabulum can require acetabular cages or additional hardware constructs to secure the acetabular components3-6. In this case, we present a 63-year-old patient with a chronic infection following right hip hemiarthroplasty that eroded through the superior acetabulum into the upper pelvis. The patient underwent a two-stage revision total hip arthroplasty where the second stage re-implant utilized a novel inverted acetabular double cup construct in which an inverted acetabular cup was placed superiorly to and served as a buttress for the anatomic acetabular cup.

SURGICAL TECHNIQUE:

To fill the superior pseudo-acetabular defect and create a buttress for the superior aspect of the anatomic acetabulum, an inverted acetabular cup was used in lieu of an acetabular reconstruction cage. After reaming both the superior defect and anatomic acetabulum, a porous metal, multi-hole acetabular cup was inserted in an inverted position (i.e. upside-down) into the superior defect and impacted into position. Next, a porous metal, multi-hole acetabular revision cup of larger diameter was inserted into the anatomic acetabulum and impacted into position. With both cups placed, the entire construct was axially impacted with hemisphere to hemisphere contact of the inverted cup and the anatomic acetabular cup, creating a buttress support. The construct was secured with 1 self-tapping titanium screw through the inverted cup, and 5 self-tapping titanium screws in and about the inverted cup and anatomic acetabular cup, all of which obtained solid bone fixation. Defects between the 2 cups were filled with acetabular bone reaming remnants and 5 mL of Cerament bone graft substitute. A central plug screw was placed into the anatomic acetabular cup. A constrained acetabular cup was placed into anatomic acetabular cup, impacted, and locked in position.

SUMMARY:

In this case, we present a patient that successfully underwent a two-stage right total hip arthroplasty revision where the second stage re-implant utilized the inverted double cup construct after significant acetabular bone loss. The inverted double cup construct may be a cost-effective alternative to expensive implants in order to fill large bone defects about the acetabulum and stabilize acetabular components in revision total hip arthroplasty.

References: 

1. Grosso MJ, Kozaily E, Cacciola G, Parvizi J. Characterizing femoral and acetabular bone loss in two-stage revision total hip arthroplasty for infection. J Arthroplasty 2021; 36(1):311-316.
2. Issack PS, Nousianinen M, Beksac B, Helfet DL, Sculco TP, Buly RL. Acetabular component revision in total hip arthroplasty. Part II: management of major bone loss and pelvic discontinuity. Am J Orthop 2009; 38:550-556.
3. Abu-Amer Y, Darwech I, Clohisy CJ. Aseptic loosening of total joint replacements: mechanisms underlying osteolysis and potential therapies. Arthritis Res Ther 2007; 9:S6.
4. Blumenfeld TJ. Implant choices, technique, and results in revision acetabular surgery: a review. Hip Int 2012; 22:235-247.
5. Abdel MP, Trousdale RT, Berry DJ. Pelvic discontinuity associated with total hip arthroplasty: evaluation and management. J Am Acad Orthop Surg 2017; 25(5):330-338.
6. Webb JE, McGill RJ, Palumbo BT, Moschetti WE, Estok DM. The double-cup construct: a novel treatment strategy for the management of Paprosky IIIA and IIIB acetabular defects. J Arthroplasty 2017; 32:S225-S231.