Single Wedge Femoral Stem Designs are Associated With a Higher Risk for Revision After Cementless Primary Total Hip Arthroplasty.

BACKGROUND: Cementless total hip arthroplasty (THA) femoral stems are the most commonly selected prostheses in the United States. Optimal stem geometry remains controversial with excellent survivorship reported for many designs. We compared cause-specific stem revision of single-wedge versus double-wedge designs from a multicenter US cohort. METHODS: Data from an integrated healthcare network's total joint replacement registry were used to conduct a cohort study. Primary elective cementless THAs were identified (2001 to 2018). Implant exposure groups were classified by design geometry using the system proposed by Khanuja et al. Type 1 single-wedge (n = 11,082) and type 2 double-wedge (n = 32,380) designs were compared, and other design types were excluded; the final study cohort comprised 43,462 THAs. Cause-specific multivariable Cox regressions were used to evaluate risk for revision due to infection or aseptic reasons, including loosening, instability, periprosthetic fracture, or other reasons. RESULTS: After adjustment for covariates, a higher aseptic revision risk was observed for type 1 when compared to type 2 designs (hazard ratio = 1.91, 95% confidence interval = 1.33-2.75). When looking at specific revision reasons, revision for aseptic loosening (hazard ratio = 3.46, 95% confidence interval = 2.24-5.34) was higher for type 1 versus type 2 designs. No differences were found for septic revision, instability, periprosthetic fracture, or revisions for other reasons. CONCLUSIONS: Type 1 single-wedge designs were found to have a higher risk of revision due to aseptic loosening relative to type 2 double-wedge designs. Femoral stem geometry should be considered when selecting a cementless femoral implant. LEVEL OF EVIDENCE: Level III.

Modular Tibial Stem Use and Risk of Revision for Aseptic Loosening in Cemented Primary Total Knee Arthroplasty.

BACKGROUND: Modular tibial stem extensions in total knee arthroplasty (TKA) are designed to reduce the risk of aseptic loosening of the tibial base plate. However, these implants add significant cost and an evaluation of their effectiveness in reducing this risk of loosening has not been studied in a large cohort. We sought to evaluate modular tibial stem utilization in primary TKA. METHODS: We conducted a cohort study using our integrated healthcare system's Total Joint Replacement Registry. Patients who underwent cemented primary TKA were identified (2009-2019). Propensity scores were used to 1:1 match patients without to those with a stem extension. Cox proportional-hazards regression was used to evaluate the risk for revision due to aseptic loosening. RESULTS: Ten thousand four hundred seventy six TKA with a modular tibial stem were matched to 10,476 TKA without a tibial stem. Stem utilization associated with a lower risk of revision for loosening across all postoperative follow-up (hazard ratio = 0.38, 95% confidence interval = 0.17-0.85). CONCLUSION: In a matched cohort study, we observed presence of a stem extension was associated with a lower risk of revision for aseptic loosening. Further study to identify specific risk factors for aseptic loosening and confirm the findings presented here are warranted. LEVEL OF EVIDENCE: Level III.

Reasons for Ninety-Day Emergency Visits and Readmissions After Elective Total Joint Arthroplasty: Results From a US Integrated Healthcare System.

BACKGROUND: Previous studies evaluating reasons for 30-day readmissions following total joint arthroplasty (TJA) may underestimate hospital-based utilization of healthcare resources during a patient's episode-of-care. We sought to identify common reasons for 90-day emergency department (ED) visits and hospital readmissions following primary elective unilateral TJA. METHODS: Patients from July 1, 2012 through June 30, 2015 having primary elective TJA and at least one 90-day postoperative ED-only visit and/or readmission for any reason were identified using the Kaiser Permanente Total Joint Replacement Registry. Chart reviews for ED visits/readmissions included 13 surgical and 11 medical reasons. The 2344 total hips and 5520 total knees were analyzed separately. RESULTS: Incidence of at least one ED visit following total hip arthroplasty (THA) was 13.4% and 4.5% for readmissions. The most frequent reasons for ED visits were swelling (15.6%) and pain (12.8%); the most frequent reasons for readmissions were infection (12.5%) and unrelated elective procedures (9.0%). The incidence of at least one ED visit following total knee arthroplasty (TKA) was 13.8%, and the incidence of readmission was 5.5%. The most frequent reasons for ED visits were pain (15.8%) and swelling (15.6%); the most common readmission reasons were gastrointestinal (19.1%) and manipulation under anesthesia (9.4%). CONCLUSION: Swelling and pain related to the procedure were the most frequent reasons for 90-day ED visits after both THA and TKA. Readmissions were most commonly due to infection or unrelated procedures for THA and gastrointestinal or manipulation under anesthesia for TKA. Modifications to discharge protocols may help prevent or alleviate these issues, avoiding unnecessary hospital returns.

Retrograde cerebral perfusion and delayed hyperbaric oxygen for massive air embolism during cardiac surgery.

We report a case of massive air embolism from a ventricular vent line during cardiac surgery successfully treated with emergent retrograde cerebral perfusion and delayed hyperbaric oxygen therapy. The etiologies of this rare but potentially devastating complication are discussed along with prevention and treatment options.