Treatment of Severe Acetabular Bone Loss Using a Tantalum Acetabular Shell and a Cemented Monoblock Dual Mobility Acetabular Cup

Abstract

As the number of revision total hip arthroplasty increases, innovative solutions to complex problems are needed to address challenges posed by these complex cases. Severe acetabular bone loss, including cases of pelvic discontinuity, is a notable challenge with few solutions. Hip instability after revision arthroplasty remains one of the leading causes of revision and patient morbidity. The use of pelvic distraction and a press-fit tantalum shell for chronic discontinuity and posterior column open reduction and internal fixation with acetabular revision for acute pelvic discontinuity have previously been described. Similarly, dual mobility articulations have demonstrated long-term success in minimizing instability after revision total hip arthroplasty with good long-term survivorship. Here, the authors present a surgical technique in the management of Paprosky types 2 and 3 acetabular defects often with pelvic discontinuity using a tantalum shell in combination with cemented dual mobility liner to increase the stability of the joint. Custom screw placement is facilitated with the use of a metal cutting burr, both on the back table and in situ. The dual mobility liner is cemented, thus allowing for independent positioning of the acetabular implant and bearing surface. This technique has been successfully used in 19 patients with encouraging short-term results.A cetabular bone loss is a notable challenge faced during revision total hip arthroplasty (THA). Projections estimate that the burden of revision THA in the United States will increase between 43% and 70% by 2030. 1 Pelvic discontinuity is a rare pattern of acetabular deficiency seen in between 1% and 5% of revision THA. [2][3][4] It can be defined as deficiency or compromise of both the anterior and posterior acetabular columns, thus disrupting superior and inferior connection of the hemipelvis. 5 Acute pelvic discontinuity can be managed with plating of the posterior column and revision of the acetabular shell. 6,7 Chronic pelvic discontinuity can be managed with antiprotrusio cages, cup cage reconstruction, custom triflange,

Removing Cemented Dual Mobility Liners From Acetabular Components: A Technical Tip for a Challenging Surgical Problem

“…Recently, DM cups intended for cementation have become available. In some circumstances, these cemented constructs are advantageous as they allow correction of effective acetabular position (both acetabular version and inclination) and for the use of DM when modular options are not available, facilitating the retention of well-fixed acetabular components during revision THA [ 27 ].…”

“…In these cases, cemented DM constructs—that is, a monoblock DM cup, designed for cementation, cemented into an existing acetabular component—offer a viable solution. This technique has been biomechanically validated [ 21 ], and several small studies [ [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] ] have reported favorable outcomes at early follow-up.…”

Cementing a Monoblock Dual-Mobility Implant into a Fully Porous Cup in Revision Total Hip Arthroplasty to Address Hip Instability

“…Additionally, the authors reported rates of all-cause acetabular survival from re-revision of 96.7% at 6 months, 93.3% at 1 year, and 89.7% at 2 years 9 . Physicians should be aware of the possibility for intra-prosthetic dislocations, as although this complication is rare, it has been reported in the literature 7,10 . Important Tips:…”

“…A cemented dual-mobility implant can be utilized in a well-fixed acetabular shell without evidence of loosening or osteolysis. Rationale: Dual-mobility implants have become increasingly utilized because of their advantages: (1) ability to decrease dislocation rate without increasing constraint and (2) increasing range of motion with reduced impingement risk [2][3][4][5][6][7][8] . These implants are particularly useful in the setting of revision cases with large acetabular bone defects.…”

“…Moreover, acetabular cup survival was excellent, with 100% survival at 1 year and 96.2% at 2 years. Expected Outcomes: The use of a dual-mobility implant is a viable treatment option in cases of revision total hip arthroplasty, particularly those in which postoperative stability is a concern; monoblock dual-mobility implants cemented into porous shells are particularly useful in this setting [2][3][4][5][6][7][8] . These trends are similarly seen in patients treated with monoblock dual-mobility implants cemented into porous shells.…”