Association of an Early Interest in Orthopedic Surgery with Match Rate into Orthopedic Surgery.

OBJECTIVES: Orthopedic surgery residency is considered one of the most competitive specialties in which to match. Studies examining the factors associated with a successful match have neglected whether participation in an orthopedic interest group (OIG) improves the chances of orthopedic residency match. The goal of this study was to test the hypothesis that participation in the OIG would improve matching into an orthopedic surgery residency. METHODS: We performed a retrospective cohort study between May 2017 and 2019 at one state-funded medical school. All of the applicants in orthopedic surgery from 2004 to 2019 were identified and contacted for OIG membership status. The Office of Student Affairs provided academic performance data (US Medical Licensing Examination scores and third-year clinical clerkship grades), Alpha Omega Alpha and Gold Humanism Honor Society status, and demographics (race and sex) of applicants. RESULTS: Between 2004 and 2019, 67 students (56 OIG and 11 non-OIG) applied for orthopedic surgery residency match. The match rate for the OIG was 86% compared with 64% for the non-OIG group, resulting in an adjusted odds ratio (adjusted for academic performance) of 10.23 (95% confidence interval 1.14-92.3, P = 0.038). CONCLUSIONS: OIG membership was associated with a significantly higher rate of orthopedic surgery residency matches. The higher rate of match associated with OIG membership may be the result of opportunities to diversify a residency application. Future studies are needed to further evaluate the potential association between OIG involvement and orthopedic surgery match.

Viscoelastic and failure properties of two configurations of triple-folded hamstring tendons used for anterior cruciate ligament (ACL) reconstruction.

BACKGROUND: Hamstring autografts are commonly used for anterior cruciate ligament (ACL) reconstruction. Different folding techniques exist in tripling the semitendinosus. Few anatomical studies exist in evaluating their viscoelastic properties. The purpose of this study was to characterize and compare the viscoelastic and failure properties of two hamstring graft configurations, the "Z" construct and "2" construct. METHODS: Ten matched pairs of fresh-frozen cadaveric semitendinosus hamstring grafts were used to create the "2" configuration or "Z" configuration. The biomechanical testing consisted of four phases: preconditioning, where graft dimensions (mm) were measured; stress relaxation, where load, displacement and time data were collected and equilibrium relaxation (%) was calculated; dynamic creep, where the total construct elongation was calculated; and ramp-to-failure, where maximum failure load was recorded. RESULTS: The "2" configuration demonstrated recorded forces (N) significantly greater at each time point when compared to the "Z" configuration during stress relaxation (p = 0.003). The "2" configuration exhibited significantly less construct elongation (mm) during dynamic creep at 10 cycles (p = 0.008) and 2000 cycles (p = 0.0001). The maximum measured load at failure was significantly greater in the "2" configuration constructs than "Z" configuration (p = 0.013). Moreover, the axial loads at 2, 3 and 4 mm of displacement were, on average, greater in the "2" configuration than "Z" configuration (p = 0.152; p = 0.080; p = 0.012), respectively. CONCLUSION: The results of this study provide support for folding techniques for tripled grafts to provide higher viscoelastic and failure properties for techniques with less suture interfaces. Future studies can potentially evaluate the clinical significance of these findings.

Pectoralis major tear in a 23-year-old woman while performing high-intensity interval training: a rare presentation.

Pectoralis major (PM) tears are a rare injury, that commonly occurs at the sternocostal head and has a greater incidence in men, with only two previously reported cases in young and middle-aged women. The authors report a complete PM tear that occurred in a 23-year-old woman, that presented after performing a 'muscle-up'. MRI revealed PM rupture at the humeral insertion. Surgical management was performed, and patient returned to high-intensity interval training at 11 months postoperatively and reported great satisfaction. This is the first case in literature that reports a complete tear of the PM in a young woman through an atraumatic mechanism of injury with no previous alteration to the PM. With a cultural increase in wellness, atraumatic PM tear in young women should be expected and remain on the differential for any athlete that participates in high-intensity interval training.

MRI of the annular ligament of the elbow: review of anatomic considerations and pathologic findings in patients with posterolateral elbow instability.

OBJECTIVE: The annular ligament is one of the major stabilizers of the proximal radioulnar joint. However, it is one of the least studied structures in the lateral elbow because of imaging challenges and low pathologic incidence. This article will examine the anatomy of the annular ligament, its biomechanics, and its functional importance. Eight surgically proven cases of annular ligament abnormality in patients with posterolateral and nursemaid elbow, along with the associated findings, are presented. CONCLUSION: Adequate understanding of the anatomy and familiarity with the associated injuries that can be seen in annular ligament displacement or rupture will improve detection of annular ligament abnormality.

Quantifying and comparing torsional strains after olecranon plating.

PURPOSE: Any torsion experienced at a fracture site will directly translate into shearing forces and has been regarded as detrimental to healing. The purpose of this study was to determine which plating system currently on the market controls torsional forces about comminuted olecranon fractures most effectively. METHODS: Five olecranon plates (Acumed, Synthes-SS, Synthes-Ti, ITS/US Implants and Zimmer) were implanted to stabilise a simulated comminuted fracture pattern in 50 fresh-frozen, cadaveric elbows. All specimens were evaluated by dual energy X-ray absorptiometry (DXA) scan to determine bone density. Three-dimensional displacement analysis was conducted to assess fragment motion through physiologic cyclic arcs of motion. The specimens were cycled through progressive physiologic loads (0.18-5.6 kg). Movements of the fragments were statistically compared amongst the different implants using one-way analysis of variance (ANOVA) and Tukey Honestly Significant Difference (HSD) post hoc comparisons with a critical significance level of α=0.05. RESULTS: DXA bone mineral densities (BMDs) ranged from 0.465 to 0.927, with an average of 0.714. The Acumed, Synthes-SS, Synthes-Ti and Zimmer plates allowed <1° of torsion up to 1.6 kg of load. The differences between these plates at this load were not statistically significant. The ITS/US Implants plate, however, allowed significantly more torsion above loads of 2.6 kg (p=0.045) compared with all other plates. The ITS/US Implants plate allowed over 2° of torsion at 2.6 kg (p=0.012), and nearly 3° at 3.6 kg (p=0.045). The Zimmer plate consistently allowed more torsion than the Acumed plate or either of the Synthes plates, but the differences were not statistically significant. CONCLUSION: Regardless of which olecranon plate is used, the authors recommend limiting postoperative rehabilitation loads to below 1.6 kg in an effort to minimise the detrimental effects of torsion on healing. If loads over 1.6 kg are anticipated, the authors recommend the use of the Acumed plate or either of the Synthes plates.

Comparison of olecranon plate fixation in osteoporotic bone: do current technologies and designs make a difference?

OBJECTIVES: The purpose of this study is to determine if recent innovations in olecranon plates have any advantages in stabilizing osteoporotic olecranon fractures. METHODS: Five olecranon plates (Acumed, Synthes-SS, Synthes-Ti, US Implants/ITS, and Zimmer) were implanted to stabilize a simulated comminuted fracture pattern in 30 osteoporotic cadaveric elbows. Specimens were randomized by bone mineral density per dual-energy x-ray absorptiometry scan. Three-dimensional displacement analysis was conducted to assess fragment motion through physiological cyclic arcs of motion and failure loading, which was statistically compared using one-way analysis of variance and Tukey honestly significant difference post hoc comparisons with a critical significance level of α = 0.05. RESULTS: Bone mineral density ranged from 0.546 g/cm to 0.878 g/cm with an average of 0.666 g/cm. All implants limited displacement of the fragments to less than 3 mm until sudden, catastrophic failure as the bone of the proximal fragment pulled away from the implant. The maximum load sustained by all osteoporotic specimens ranged from 1.6 kg to 6.6 kg with an average of 4.4 kg. There was no statistical difference between the groups in terms of cycles survived and maximum loads sustained. CONCLUSIONS: Cyclic physiological loading of osteoporotic olecranon fracture fixation resulted in sudden, catastrophic failure of the bone-implant interface rather than in gradual implant loosening. Recent plate innovations such as locking plates and different screw designs and positions appear to offer no advantages in stabilizing osteoporotic olecranon fractures. Surgeons may be reassured that the current olecranon plates will probably adequately stabilize osteoporotic fractures for early motion in the early postoperative period, but not for heavy activities such as those that involve over 4 kg of resistance.

Mg2+-dependent conformational change of RNA studied by fluorescence correlation and FRET on immobilized single molecules.

Fluorescence correlation spectroscopy (FCS) of fluorescence resonant energy transfer (FRET) on immobilized individual fluorophores was used to study the Mg2+-facilitated conformational change of an RNA three-helix junction, a structural element that initiates the folding of the 30S ribosomal subunit. Transitions of the RNA junction between open and folded conformations resulted in fluctuations in fluorescence by FRET. Fluorescence fluctuations occurring between two FRET states on the millisecond time scale were found to be dependent on Mg2+ and Na+ concentrations. Correlation functions of the fluctuations were used to determine transition rates between the two conformations as a function of Mg2+ or Na+ concentration. Both the opening and folding rates were found to vary with changing salt conditions. Assuming specific binding of divalent ions to RNA, the Mg2+ dependence of the observed rates cannot be explained by conformational change induced by Mg2+ binding/unbinding, but is consistent with a model in which the intrinsic conformational change of the RNA junction is altered by uptake of Mg2+ ion(s). This version of FCS/FRET on immobilized single molecules is demonstrated to be a powerful technique in the study of conformational dynamics of biomolecules over time scales ranging from microseconds to seconds.