Larger stem to bone diameter ratio predicts lower cemented endoprosthesis failure.

BACKGROUND AND OBJECTIVES: With continued advances in treatment options, patients with endoprosthetic reconstruction are living longer and consequently relying upon their devices for a longer duration. Major causes of endoprosthesis failure include aseptic loosening and mechanical failure. In the setting of tumor resection, loss of bone stock and use of radiation therapy increase the risk for these complications. As such, considerations of remaining native bone and stem length and diameter may be increasingly important. We asked the following questions: (1) What was the overall rate of endoprosthesis failure at a minimum of 5-year follow-up? (2) Does resection length increase implant failure rates? (3) Does implant size and its ratio to cortical width of bone alter implant failure rates? METHODS: We retrospectively analyzed patient outcomes at a single institution between the years of 1999-2022 who underwent cemented endoprosthetic reconstruction at the hip or knee and identified 150 patients. Of these 150, 55 had a follow-up of greater than 5 years and were used for analysis. Radiographs of these patients at time of surgery were assessed and measured for resection length, bone diameter, stem diameter, and remaining bone length. Resection percentage, and stem to bone diameter ratios were then calculated and their relationship to endoprosthesis failure were analyzed. RESULTS: Patients in this cohort had a mean age of 55.8, and mean follow-up of 59.96 months. There were 78 distal femoral replacements (52%), 16 proximal femoral replacements (10.7%), and 56 proximal tibial replacements (37.3%). There were five patients who experienced aseptic loosening and six patients who experienced mechanical failure. Patients with implant failure had a smaller mean stem to bone diameter (36% vs. 44%; p = 0.002). A stem to bone diameter of 40% appeared to be a breaking point between success and failure in this series, with 90% of patients with implant failure having a stem: bone ratio less than 40%. Stem to bone ratio less than 40% increased risk for failure versus stems that were at least 40% the diameter of bone (6/19 [31.6%] vs. 0/36 [0%]; odds ratio 0.68; p < 0.001). Resection length did not appear to have an impact on the rates of aseptic loosening and mechanical failure in this series. CONCLUSIONS: Data from this series suggests a benefit to using stems with a larger diameter when implanting cemented endoprostheses at the hip or knee. Stems which were less than 40% the diameter of bone were substantially more likely to undergo implant failure.

Is Program Director Gender Associated With Gender Diversity Among Orthopaedic Surgery Residency Programs?

BACKGROUND: Women remain underrepresented in leadership roles, faculty roles, and among residents in orthopaedic surgery. It has been suggested that having women in leadership positions in orthopaedic surgery may help to increase the gender diversity of residency programs. However, to our knowledge, no study has explored the relationship, if any, between the gender of the residency program director and the percentage of women in the residency program. QUESTIONS/PURPOSES: (1) Is the program director's gender associated with differences in the percentage of women orthopaedic surgery residents? (2) Do women and men differ in the time to appointment of program director? METHODS: A list of 207 orthopaedic surgery residencies was obtained from the Accreditation Council for Graduate Medical Education (ACGME) website for the academic year 2021 to 2022. The study excluded 6% (13) of programs; 4% (8) were those without ACGME accreditation and those with initial accreditation, and 2% (5) did not have updated 2021 to 2022 resident lists. Descriptive information on 194 programs was obtained from publicly accessible resources from July 2021 through July 2022. The institution's website and the American Medical Association's (AMA) Fellowship and Residency Electronic Interactive Database (FREIDA) was used to collect residency program characteristics and resident demographics [ 2 ]. Doximity, Healthgrades, and LinkedIn were used to further collect current orthopaedic surgery residency program director demographics, including gender, age, and education/training history. To determine gender, photographs and pronouns (she/her/hers or he/him/hers) used in their biographies were used first. To confirm this, secondary sources were used including their NPI profile, which lists gender; Doximity; and their LinkedIn profile. Scopus was used to analyze research output by the program directors-using the Hirsch index (h-index) as the primary bibliometric metric. A total of 194 program directors were identified, of whom of 12% (23) were women and 88% (171) were men. Of the 4421 total residents among these programs, 20% (887) were women and 80% (3534) were men. A univariate analysis comparing program directors was conducted, with continuous variables analyzed using an independent-sample t-test and categorical variables analyzed using a Pearson chi-square test. With the numbers available, a post hoc statistical power calculation indicated that we could detect an 32% difference in the percentage of women in a program as significant with 80% power at the p < 0.05 level, whereas we might have been underpowered to discern smaller differences than that. RESULTS: With the numbers available, we found no difference in the percentage of women in residency programs run by women program directors than in programs in which the program director was a man (22% [125 of 558] versus 20% [762 of 3863], mean difference 2% [95% CI -1.24% to 7.58%]; p = 0.08). Comparing women to men program directors, women had fewer years between residency completion and appointment to the position of program director (8 ± 2 years versus 12 ± 7 years, mean difference 4 years [95% CI 2.01 to 7.93 years]; p = 0.02) and had a lower mean h-index (7 ± 4 versus 11 ± 11, mean difference 4 [95% CI 1.70 to 6.56]; p = 0.03) and number of publications (24 ± 23 versus 41 ± 62, mean difference 17 [95% CI 3.98 to 31.05]; p = 0.01), although they did not differ in terms of their advanced degrees, duration of training, or likelihood of having taken a fellowship. CONCLUSION: Orthopaedic residency programs that were run by women did not contain a higher percentage of women residents, suggesting that the gender of the individual in that role may not be as important as has been speculated by others. Future studies should investigate the intersectionality of gender, race, and ethnicity of residents, program directors, and current faculty. CLINICAL RELEVANCE: The fact that women were placed in program director roles earlier in career may also carry special jeopardy for them. Those roles are difficult and can impair a faculty member's ability to conduct individual research, which often is key to further academic promotions. Given that and the fact that the gender of the program director was not associated with differences in gender composition of residency programs, we believe that increasing mentorship and access to pipeline programs will help promote diversity in residency programs.