Browsing by Author "Dillon, Mark T."

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Patient- and Procedure-Specific Variables Associated With Removal or Revision of Radial Head Arthroplasty
    (Kaiser Permanente, 2022) Dillon, Mark T.; Dontsi, Makdine; Alabaster, Amy; Vance, Michael C.; Orthopaedic Surgery, School of Medicine
    Introduction: The purpose of this retrospective review was to identify risk factors associated with removal or revision following radial head arthroplasty. Methods: Patients undergoing primary radial head arthroplasty between 2009 and 2015 with a minimum follow-up of 1 year were identified. Descriptive and bivariate statistics were used to analyze the characteristics of patients requiring implant removal or revision and multivariable analysis was performed to calculate hazard ratios. Results: There were 312 patients included in the final cohort with a median follow-up of 3.8 years. Thirty-five patients (11.2%) underwent prosthesis removal or revision. There was an increased percentage of implants removed or revised in patients under age 40, with surgery performed for chronic indications compared to acute trauma, and with the use of press-fit stems compared to polished. Discussion: It appears younger patient age, chronic surgical indications, and certain aspects of prosthesis design may influence rates of removal or revision.
  • Thumbnail Image
    Item
    Results of Anatomic Total Shoulder Arthroplasty with the Arthrex Eclipse Stemless Humeral Implant in Patients Over 70 Years of Age
    (Elsevier, 2025) Dillon, Mark T.; Denard, Patrick J.; ShARC Group; Werner, Brian C.; Orthopaedic Surgery, School of Medicine
    Background Anatomic total shoulder arthroplasty (aTSA) is a well-described technique for addressing glenohumeral osteoarthritis. Little has been written on outcomes for newer stemless humeral implants in older patients, with none looking specifically at an implant relying on screw fixation. The purpose of this study is to evaluate the clinical and radiographic outcomes for patients over 70 years of age undergoing aTSA with the Eclipse (Arthrex Inc., Naples, FL, USA) stemless humeral component. Methods A retrospective review using a multicenter shoulder arthroplasty registry was performed evaluating all patients over 70 years of age who underwent aTSA with a stemless humeral implant for a diagnosis of glenohumeral osteoarthritis and had a minimum follow-up of 2 years. Thirty-seven patients met the study criteria and were matched for comparative analysis to 37 patients 65 years and younger. Outcome scores were obtained preoperatively and at 2 years postoperatively using the visual analog scale, Constant-Murley, American Shoulder and Elbow Surgeons (ASES), and Western Ontario Osteoarthritis Index (WOOS) scores. The percentage of patients in each group who exceeded the Minimal Clinically Important Difference (MCID) for the ASES and WOOS was reported. When available, postoperative radiographs were evaluated for the presence of radiolucent lines and calcar resorption. Results There was a statistically significantly higher preoperative WOOS score in the older patient group; otherwise, there was no statistical difference between the 2 groups in regard to baseline scores or range of motion. At 2-year follow-up, older patients were noted to have significantly better visual analog scale, ASES, WOOS, and Constant-Murley scores than younger patients (P < .05). For the ASES, all patients over the age of 70 years achieved MCID compared with 84% of those 65 years and younger (P = .011), whereas for the WOOS, 100% of older patients achieved MCID compared with 86% of those in the control group (P = .022). Postoperative range of motion was generally not different between the 2 groups, although older patients had better active internal rotation at 90° of abduction (P = .002). Partial calcar resorption was noted in 1 patient in each age group. Radiolucent lines were noted in 2 patients over the age of 70 years and 1 patient 65 years or younger. Discussion Patients over the age of 70 years with glenohumeral osteoarthritis undergoing aTSA with a stemless humeral component have equivalent, if not better, outcomes when compared with younger patients. Age alone does not appear a limitation for stemless aTSA.
  • Thumbnail Image
    Item
    The effect of a statewide COVID-19 shelter-in-place order on shoulder arthroplasty for proximal humerus fracture volume and length of stay
    (Elsevier, 2021) Dillon, Mark T.; Chan, Priscilla H.; Prentice, Heather A.; Royse, Kathryn E.; Paxton, Elizabeth W.; Okike, Kanu; Khatod, Monti; Navarro, Ronald A.; Orthopaedic Surgery, School of Medicine
    Background: Although the COVID-19 pandemic has disrupted elective shoulder arthroplasty throughput, traumatic shoulder arthroplasty procedures are less apt to be postponed. We sought to evaluate shoulder arthroplasty utilization for fracture during the COVID-19 pandemic and California's associated shelter-in-place order compared to historical controls. Methods: We conducted a cohort study with historical controls, identifying patients who underwent shoulder arthroplasty for proximal humerus fracture in California using our integrated electronic health record. The time period of interest was following the implementation of the statewide shelter-in-place order: March 19, 2020-May 31, 2020. This was compared to three historical periods: January 1, 2020-March 18, 2020, March 18, 2019-May 31, 2019, and January 1, 2019-March 18, 2019. Procedure volume, patient characteristics, in-hospital length of stay, and 30-day events (emergency department visit, readmission, infection, pneumonia, and death) were reported. Changes over time were analyzed using linear regression adjusted for usual seasonal and yearly changes and age, sex, comorbidities, and postadmission factors. Results: Surgical volume dropped from an average of 4.4, 5.2, and 2.6 surgeries per week in the historical time periods, respectively, to 2.4 surgeries per week after shelter-in-place. While no more than 30% of all shoulder arthroplasty procedures performed during any given week were for fracture during the historical time periods, arthroplasties performed for fracture was the overwhelming primary indication immediately after the shelter-in-place order. More patients were discharged the day of surgery (+33.2%, P = .019) after the shelter-in-place order, but we did not observe a change in any of the corresponding 30-day events. Conclusions: The volume of shoulder arthroplasty for fracture dropped during the time of COVID-19. The reduction in volume could be due to less shoulder trauma due to shelter-in-place or a change in the indications for arthroplasty given the perceived higher risks associated with intubation and surgical care. We noted more patients undergoing shoulder arthroplasty for fracture were safely discharged on the day of surgery, suggesting this may be a safe practice that can be adopted moving forward.