Articulating Hip Spacers with a Constrained Acetabular Liner: Effect of Acetabular Bone Loss and Cementation Quality.

Articulating hip spacers for periprosthetic joint infection (PJI) offer numerous advantages over static spacers such as improved patient mobilization, hip functionality, and soft tissue tension. Our study aimed to determine complication rates of a functional articulating spacer using a constrained liner to determine the role of acetabular cementation mantle and bone loss on the need for second-stage surgery. A retrospective review of 103 patients was performed and demographic information, spacer components and longevity, spacer-related complications, reinfection rates, and grade of bone loss and acetabular cement mantle quality were determined. There was no significant difference in spacer-related complications or reinfection rate between PJI and native hip infections. 33 of 103 patients (32.0%) elected to retain their spacers. Between patients who retained their initial spacer and those who underwent reimplantation surgery, there was not a significant difference in cement mantle grade (p = 0.52) or degree of bone loss (p = 0.78). Functional articulating antibiotic spacers with cemented constrained acetabular liners demonstrate promising early results in the treatment of periprosthetic and native hip infections. The rate of dislocation events was low. Further efforts to improve cement fixation may help decrease the need for second-stage reimplantation surgery.

Articulating Knee Spacers in the Treatment of Periprosthetic Joint Infection: All Polyethylene Tibia or Tibial Insert?

BACKGROUND: The best antibiotic spacer for periprosthetic knee joint infection treatment is unknown. Using a metal-on-polyethylene (MoP) component provides a functional knee and may avoid a second surgery. Our study investigated complication rates, treatment efficacies, durabilities, and costs of MoP articulating spacer constructs using either an all-polyethylene tibia (APT) or a polyethylene insert (PI). We hypothesized that while the PI would cost less, the APT spacer would have lower complication rates and higher efficacies and durabilities. METHODS: A retrospective review evaluated 126 consecutive articulating knee spacer (64 APTs and 62 PIs) cases from 2016 to 2020 was performed. Demographic information, spacer components, complication rates, infection recurrence, spacer longevity, and implant costs were analyzed. Complications were classified as follows: spacer-related; antibiotic-related; infection recurrence; or medical. Spacer longevity was measured for patients who underwent reimplantation and for those who had a retained spacer. RESULTS: There were no significant differences in overall complications (P < .48), spacer-related complications (P = 1.0), infection recurrences (P = 1.0), antibiotic-related complications (P < .24), or medical complications (P < .41). Average time to reimplantation was 19.1 weeks (4.3 to 98.3 weeks) for APT spacers and 14.4 weeks (6.7 to 39.7 weeks) for PI spacers (P = .09). There were 31% (20 of 64) of APT spacers and 30% (19 of 62) of PI spacers that remained intact for an average duration of 26.2 (2.3 to 76.1) and 17.1 weeks (1.7 to 54.7) (P = .25), respectively, for patients who lived for the duration of the study. PI spacers cost less than APT ($1,474.19 versus $2,330.47, respectively; P < .0001). CONCLUSION: APT and PI tibial components have similar results regarding complication profiles and infection recurrence. Both may be durable if spacer retention is elected, with PI constructs being less expensive.

Catastrophic Trunnion Failure in an Anatomic Titanium Alloy Stem.

Introduction: Certain titanium alloy stems have been shown to be susceptible to failure at the neck with catastrophic trunnion failure. Failure has been particularly noted in the single wedge Accolade 1 stem design. Other stems also used this alloy including the anatomic designed Citation stem. Methods: This case series details 3 catastrophic failures of the TMZF version of the Citation femoral stem. Results: Each of these failures appear to be attributed to cyclical wear of the TMZF trunnion against the cobalt chromium femoral head. Wear resulted in ultimate implant failure and significant metal debris in the joint capsule at the time of revision surgery. Discussion: While surgeons are aware of the risk of catastrophic failure for the Accolade 1 stem, failure may similarly happen in the TMZF Citation stem. Surgeons should monitor these implants with care and discuss the potential for trunnion failure with their patients.

Tibial Osteolysis After Long-Term Isolated Polyethylene Patellar Resurfacing.

Isolated patellar resurfacing served as an early treatment for patellofemoral arthritis but was abandoned because of erosion of the native femoral trochlear groove over time. We present the case of a large native tibial osteolytic lesion 20 years after isolated patellar resurfacing with a cemented polyethylene component. The patient had severe tricompartmental arthritic changes. The patellar component was very worn, and the resultant particle debris produced a large cavitary lesion in the proximal tibia. Osteolysis is a rare complication in patellofemoral arthroplasty, and, to our knowledge, this is the first reported case of native tibial osteolysis after isolated patellar resurfacing. The patient was treated with initial curettage and bone grafting of the lesion followed by total knee arthroplasty with a tibial cone and stemmed tibial fixation.