Background:The current U.S. orthopaedic residency application process is becoming increasingly impersonal in the wake of an increasing number of applications. Through an analysis of orthopaedic surgery residency application statistics, we have highlighted the effect that the number of orthopaedic applications has on match rate, and we have suggested methods for a more personalized application process.Methods: Data from the Association of American Medical Colleges (AAMC) and the National Resident Matching Program (NRMP) for United States orthopaedic residency applicants from 2008 to 2018 were collected. These data included the average number of applications submitted per applicant, the average number of applications received per program, the total number of residency positions offered in the U.S., the total number of U.S. applicants, and the total number of U.S. applicants who matched to a U.S. orthopaedic surgery residency program. U.S. applicant match rates and the average number of applications received per residency position offered were calculated. Linear regression models were used to determine the rate at which these variables changed over time.

Background: Animal models are used to guide management of periprosthetic implant infections. No adequate model exists for periprosthetic shoulder infections, and clinicians thus have no preclinical tools to assess potential therapeutics. We hypothesize that it is possible to establish a mouse model of shoulder implant infection (SII) that allows noninvasive, longitudinal tracking of biofilm and host response through in vivo optical imaging. The model may then be employed to validate a targeting probe (1D9-680) with clinical translation potential for diagnosing infection and image-guided débridement. Methods: A surgical implant was press-fit into the proximal humerus of c57BL/6J mice and inoculated with 2 μL of 1 × 10 3 (e3), or 1 × 10 4 (e4), colony-forming units (CFUs) of bioluminescent Staphylococcus aureus Xen-36. The control group received 2 μL sterile saline. Bacterial activity was monitored in vivo over 42 days, directly (bioluminescence) and indirectly (targeting probe). Weekly radiographs assessed implant loosening. CFU harvests, confocal microscopy, and histology were performed. Results: Both inoculated groups established chronic infections. CFUs on postoperative day (POD) 42 were increased in the infected groups compared with the sterile group (P < .001). By POD 14, osteolysis was visualized in both infected groups. The e4 group developed catastrophic bone destruction by POD 42. The e3 group maintained a congruent shoulder joint. Targeting probes helped to visualize low-grade infections via fluorescence. Discussion: Given bone destruction in the e4 group, a longitudinal, noninvasive mouse model of SII and chronic osteolysis was produced using e3 of S aureus Xen-36, mimicking clinical presentations of chronic SII. Conclusion: The development of this model provides a foundation to study new therapeutics, interventions, and host modifications.

Introduction Recurrent atrial fibrillation (AF) after ablation is associated with reconnection of initially isolated pulmonary vein (PV) trigger sites. Substrates are often targeted in addition to PVI, but it is unclear how substrates progress over time. We studied if substrates in recurrent AF are conserved or have developed de novo from pre-ablation AF. Methods and Results Of 137 patients undergoing Focal Impulse and Rotor Mapping (FIRM) at their index procedure for AF, 29 consecutive patients (60 ± 8 years, 79% persistent) recurred and were also mapped at repeat procedure (21 ± 20 months later) using carefully placed 64-pole baskets and RhythmView™ (Topera, Menlo Park, CA, USA) to identify AF sources and disorganized zones. Compared to index AF, recurrent AF had a longer cycle length (177 ± 21 vs. 167 ± 19 milliseconds, P = 0.01). All patients (100%) had 1 or more conserved AF rotors between procedures with surrounding disorganization. The number of sources was similar for recurrent AF post-PVI versus index AF (3.2 ±1.4 vs. 3.1 ± 1.0, P = 0.79), but was lower for recurrent AF after FIRM+PVI versus index AF (4.4 ± 1.4 vs. 2.9 ± 1.7, P = 0.03). Overall, 81% (61/75) of AF sources lay in conserved regions, while 19% (14/75) were detected de novo. Conclusion Electrical propagation patterns for recurrent AF after unsuccessful ablation are similar in individual patients to their index AF. These data support temporospatial stability of AF substrates over 1–2 years. Trials should determine the relative benefit of adding substrate mapping and ablation to PVI for recurrent AF.

Background Cemented endoprosthetic reconstruction after resection of primary bone sarcomas has been in common use for decades. Although multiple studies have reported the survivorship of primary endoprostheses, implant survivorship after revision surgery is less well established. Given that earlier advances in systemic therapy improved survival of patients with sarcoma, the usage of revision endoprostheses can be expected to increase and, as such, understanding revision implant survivorship will help to inform patient and surgeon expectations. Additionally, as new implants are developed that allow alternative reconstruction options, a normative dataset establishing accurate expectations for revision cemented endoprostheses is a critical benchmark by which to measure progress. Questions/purposes (1) What is the implant survivorship free of all-cause revision for primary and revision cemented distal femoral replacements (DFRs) used in the treatment of malignant or benign tumors? (2) What are the most common indications for revision of primary and revision DFRs in an oncology population with mean follow-up of more than 10 years? (3) How does the indication for revision of a primary DFR affect the subsequent risk for and type of revision DFR complication? (4) What patient, tumor, or implant characteristics are associated with improved survivorship free of revision in cemented DFRs used in patients treated initially for primary malignant or benign tumors? Methods This was a retrospective, comparative study using our institution's longitudinally-maintained database of 806 cemented endoprostheses starting in 1980 and assessed through December 31, 2018. In all, 365 DFRs were inserted during this time, but 14% (51 of 365) were placed for nonprimary bone tumors and 1% (5 of 365) were cementless reconstructions, leaving 309 cemented DFRs. Seventyone percent (218 of 309) were primary implants and 29 percent (91 of 309) were revision implants (used to revise a prior DFR in all patients). During this time period, our strong bias was to use cemented stems and, thus, nearly all of our patients had cemented stems. Six percent (13 of 218) of primary DFRs were implanted more than 2 years before the study end; however, they lacked 2 years of follow-up data and, thus, were considered lost to follow-up, leaving Each author certifies that there are no funding or commercial associations (consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article related to the author or any immediate family members. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request. Clinical Orthopaedics and Related Research® neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use.

Background The durability of endoprostheses after limb salvage surgery is influenced by surgical factors (resection length, implant location, and residual bone quality), implant design (modular versus custom design, rotating versus fixed hinge, coating, collars, and the use of cross pins), and host factors (patient's immune status, activity One of the authors (NMB) certifies receipt of personal payments or benefits, during the study period, in an amount of USD 100,001 to USD 1,000,000 from Daiichi Sankyo Inc; in an amount of USD 10,000 to USD 100,000 from Onkos Surgical Inc; and in an amount of USD 10,000 to USD 100,000 from Zimmer Biomet Holdings Inc. All ICMJE Conflict of Interest Forms for authors and Clinical Orthopaedics and Related Research® editors and board members are on file with the publication and can be viewed on request. Clinical Orthopaedics and Related Research® neither advocates nor endorses the use of any treatment, drug, or device. Readers are encouraged to always seek additional information, including FDA approval status, of any drug or device before clinical use.

Background: Acute colonic pseudo-obstruction (Ogilvie syndrome [OS]) is a rare but devastating condition that can develop in orthopaedic patients postoperatively. The objective of this study was to identify the risk factors for developing OS after total hip arthroplasty (THA) or total knee arthroplasty (TKA) and to compare the outcomes between patients who did and did not develop OS postoperatively. Methods: This was a retrospective review using the National Inpatient Sample, a national database incorporating inpatient hospitalization information. ICD-9 codes were used to identify patients who underwent primary and revision THA or TKA. Patients were separated based on the diagnosis of OS. Primary outcomes assessed included patient mortality, postoperative complications, length of stay, and cost during index hospitalization. Results: From 2001 to 2014, a total of 12,541,169 patients underwent primary and revision THA or TKA. Of those, 3,182 patients (0.03%) developed OS postoperatively. There was an increased incidence of OS in revision THA and TKA compared with primary THA and TKA. Fluid and electrolyte disorders were associated with the largest increased adjusted risk of OS. Patients with OS had an increased adjusted risk of overall postoperative complications and being discharged to skilled nursing facility. Patients with OS had an increased average length of stay and hospitalization cost compared with patients without OS. Discussion: Given our findings, the risk factors for the development of OS, including revision surgery, should be identified and minimized during the perioperative period to prevent the development of this morbid and potentially life-threatening complication. Level of Evidence: III (Retrospective cohort study).

Background: The objective of this study was to describe the incidence of aseptic loosening (AL) of cemented stem distal femoral replacements (DFR) and to identify modifiable risk factors for its development. Methods: A retrospective review was performed of 245 consecutive primary, cemented stem DFRs implanted at a single institution over a 40-year period. The primary outcome was revision surgery for AL. A multivariate analysis was performed to identify risk factors for AL. Radiographs were reviewed to identify stem tip location, which was defined as diaphyseal or metaphyseal. Implant survival to AL was compared using Kaplan-Meier analysis. Results: AL and structural failure were the most common causes of implant failure (incidence 11.8%, 29/ 245). Younger age (P ¼ .002), male sex (P ¼ .01), longer resection length (P ¼ .04), and nonmodular implants (P ¼ .002) were all significantly associated with AL. After 1:1 matching, stem tip location in metaphyseal bone was independently associated with AL (P ¼ .04). 36% (9/25) of implants that loosened had a stem tip located in the metaphysis vs only 8% (2/25) of implants that did not fail. 30-year survival to AL was lower for implants with a metaphyseal stem tip than implants with a diaphyseal stem tip (22.7% vs 47.6%; P ¼ .11). Conclusion:A stem tip location in metaphyseal bone is associated with diminished survival to AL. When templating before DFR, stem tip location can assist in identifying high-risk reconstructions that may benefit from alternative or supplemental fixation techniques to prevent the development of AL.

Background: There are few data on injuries suffered by collegiate water polo athletes. Purpose: To describe the epidemiology of injuries suffered by National College Athletic Association (NCAA) male and female water polo players by using injury surveillance data over a 5-year period. Study Design: Descriptive epidemiology study. Methods: Deidentified data on all water polo injuries and illnesses recorded in the Pac-12 Sports Injury Research Archive from July 2016 through June 2021 were obtained and analyzed. Three men’s and 4 women’s teams were observed for the entire 5-year period, and 1 men’s and 1 women’s team was observed from July 2018 through June 2021. Results: During the observation period, 729 injuries were recorded in the database, with no differences in overall injury rates between male and female athletes (relative risk [RR] = 1.0; 95% CI, 0.9-1.2); 33.7% of injuries required a physician encounter, and 3.6% required surgery. The shoulder was the most injured body part, making up 20.6% of all injuries, followed by the head/face (18.8%) and hand/wrist/forearm (11.7%). Shoulder tendinopathy was the most common shoulder injury diagnosis (4.5% of all injuries). Concussion was the most common injury diagnosis overall, making up 11.4% of injuries, and 81.9% of concussions occurred outside of competition. Male athletes were significantly more likely than female athletes to have a concussion in an off-season practice (RR, 3.25; 95% CI, 1.2-8.8) and via contact with another player (RR, 2.9; 95% CI, 1.3-6.4). Half of the 26 surgical procedures occurring over the observation period were for chronic joint trauma of the groin/hip/pelvis/buttock, with 9 of those 13 being for femoroacetabular impingement specifically. Conclusion: Among NCAA water polo athletes, the shoulder was the most injured body part; however, shoulder injuries rarely required missed time from sport or necessitated surgical intervention. Concussions were the most common injury diagnosis, had the worst return-to-play outcomes among common diagnoses, and were mostly sustained outside of competition. Femoroacetabular impingement was found to be the dominant diagnosis for which surgical intervention was required.