Double-Spin Leukocyte-Rich Platelet-Rich Plasma Is Predominantly Lymphocyte Rich With Notable Concentrations of Other White Blood Cell Subtypes.

Purpose: To comprehensively characterize a double-spin leukocyte-rich platelet-rich plasma (LR-PRP) formulation and to compare it with whole blood (WB) by quantitatively assessing platelet and WB cell subtype concentrations in each. Methods: Prospective human ex vivo analysis with 12 healthy adult men with ages ranging from 25 to 31 was performed in a controlled laboratory setting. The main outcome measure was the leukocyte profile of human LR-PRP. Results: In LR-PRP, lymphocytes were the predominant WB cell type (11.94 ± 2.97 × 103 cells/µL) followed by neutrophils (3.72 ± 1.28 × 103 cells/µL). The mean cumulative percentage of granulocytes was 23% ± 8% and agranulocytes was 77% ± 18%. There was a significant difference observed between granulocyte and agranulocyte percentage within both WB (P = .004, [95% CI: (7%,31%)]) and LR-PRP (P < .0001, [95% CI: (42%,66%)]) groups. In addition, there was a significant difference observed between the WB and LR-PRP granulocyte percentages (P < .0001, [95% CI: (29%,43%)]) and between the WB and LR-PRP agranulocyte percentages (P < .0001, [95% CI: (30%,42%)]). Conclusions: Our study found that LR-PRP is predominantly lymphocyte rich with notable concentrations of other WB cell subtypes, including neutrophils, monocytes, eosinophils, basophils, and large unstained cells. While these subtypes are not routinely reported, they may play a role in modulating the local inflammatory environment. We also found significant differences in WB cell subtype concentrations between WB and LR-PRP. Clinical Relevance: PRP has been routinely used in many clinical practices without clear indications for its use and lacks standardization in its formulation. This study provides a comprehensive characterization of a broadly used PRP, LR-PRP, and further characterizes subtypes of WBC cells present in LR-PRP that have not been previously reported. Comprehensively reporting these subtypes in clinical trials of PRP is crucial to understanding how these cells participate in PRP's therapeutic potential. This type of data can help standardize future PRP formulations and improve patient outcomes.

Relation of Doximity ranking and matched applicant characteristics in orthopedic residency programs.

Orthopedic surgery residency applicants often turn to data from many online ranking platforms to select programs. The purpose of this study was to determine if programs belonging to different Doximity ranking groups and US geographical regions favor certain applicant characteristics in order to give prospective residents more data to make informed application decisions. 2019 Doximity rankings and matched applicant data from the 2019 Association of American Medical Colleges Residency Navigator were collected and used to determine differences among matched applicant characteristics in Doximity ranking groups and US regions. Matched applicants from the top Doximity ranking group had, on average, significantly more peer-reviewed publications than those of any other ranking group. Among US regions, matched applicants in South Atlantic programs had, on average, significantly fewer peer-reviewed publications than those in Mid Atlantic programs. Residents at South Atlantic programs spent a significantly higher percentage of their first-year training in ambulatory community settings than those in Mid Atlantic, Pacific, or East North Central programs. In conclusion, Doximity ranking is associated with certain applicant qualities more than others, and applicants can use the information in this study to strategically apply to institutions with similar training and educational goals.

Dynamic Ultrasound Uniquely Reveals Anterior Capsular Tear Communicating With Vastus Intermedius Fibers.

We present a case of an anterior capsular tear of the right knee in a previously healthy, active individual. The patient was a 31-year-old male seen one month after the onset of throbbing anterior right knee pain, which progressed to sharp suprapatellar pain over the next three months. Both dynamic ultrasound (US) and MRI were obtained. Dynamic US revealed a tear of the anterior capsule of the right knee complicated by a suprapatellar effusion communicating into the vastus intermedius fibers of the quadriceps tendon. However, these findings were not evident on MRI. In addition to discussing this unique pathology, we highlight the utility of both standard and dynamic US in establishing diagnoses for capsular pathologies.

Rectus femoris intrasubstance tear in a collegiate football kicker and its mechanism.

Rectus femoris muscle belly tears have not been reported in the literature to our knowledge. This is a case of an isolated rectus femoris intrasubstance tear in a healthy college football kicker possibly caused by the eccentric and concentric load cycles associated with kicking activities. Dynamic ultrasound was crucial in establishing a diagnosis and investigating the mechanism behind this rare injury.

Content Evaluation of Physical Medicine and Rehabilitation Residency Websites.

BACKGROUND: Prospective Physical Medicine and Rehabilitation (PM&R) applicants commonly view residency program websites to make informed decisions about where to submit their applications. To our knowledge, this is the first comprehensive review of the availability and accessibility of online content for PM&R residency programs. OBJECTIVE: To evaluate the comprehensiveness of PM&R residency websites to inform prospective applicants about the information readily available to them and identify deficient areas for program directors to address. DESIGN: Cross-sectional analysis of residency program websites using quantitative and descriptive statistics. SETTING: World Wide Web (Internet). SUBJECTS: 87 PM&R civilian residency program websites listed on the Fellowship and Residency Electronic Interactive Database (FREIDA). MAIN OUTCOME MEASUREMENTS: The presence or absence of 25 predetermined criteria on residency program websites. RESULTS: The individual residency program websites had a mean ± SD of 12.3 ± 4.3 (49.1%) of the 25 criteria sought. The programs ranged from having as few as one to as many as 19 of the 25 criteria. Twenty programs had 9 or fewer criteria, 35 programs had 10 to 14 criteria, 31 programs had 15 to 18 criteria, and one program had 19 criteria available online. No PM&R residency website had all 25 criteria. There was a significant association between a program's Doximity ranking as top 20 or not and the citation of published research projects by faculty on a PM&R website (P = .026), but the other 24 criteria had no significant associations. CONCLUSIONS: Most PM&R residency websites currently do not include comprehensive information about their programs for prospective applicants.

Effects of Aspirin on Growth Factor Release From Freshly Isolated Leukocyte-Rich Platelet-Rich Plasma in Healthy Men: A Prospective Fixed-Sequence Controlled Laboratory Study.

BACKGROUND: The benefits of platelet-rich plasma (PRP) are believed to be in part dependent on growth factor release after platelet activation. Platelet activation is complex and involves multiple mechanisms. One important mechanism is driven by cyclooxygenase 1 (COX-1)-mediated conversion of arachidonic acid (AA) to precursor prostaglandins that then mediate proinflammatory responses that trigger growth factor release. Acetylsalicylic acid (ASA; also known as aspirin) is known to irreversibly inhibit COX-1, thereby blocking AA-mediated signaling; however, it is unclear whether ASA use alters growth factor release from freshly isolated PRP. PURPOSE: To assess the effects of low-dose ASA use on activation of growth factor release from freshly isolated human PRP via AA and thrombin (TBN). STUDY DESIGN: Controlled laboratory study. METHODS: Twelve healthy men underwent blood collection and leukocyte-rich PRP (LR-PRP) preparation through a double-spin protocol to obtain baseline whole blood and PRP counts the same day. PRP was aliquoted into 3 groups: nonactivated, AA activated, and TBN activated. Immediately after activation, the concentrations of transforming growth factor ß1 (TGF-ß1), vascular endothelial growth factor (VEGF), and platelet-derived growth factor AB (PDGF-AB) were measured using enzyme-linked immunosorbent assays (ELISAs). The same 12 participants were then placed on an 81-mg daily dose of oral ASA for 14 days. Repeat characterization of whole blood and PRP analyses was done on day 14, followed by repeat ELISAs of growth factors under the same nonactivated and activated settings as previously stated. RESULTS: Fourteen days of daily ASA had no effect on the number of platelets and leukocytes measured in whole blood and LR-PRP. Compared with nonactivated LR-PRP, AA- and TBN-mediated activation led to significant release of VEGF and PDGF-AB. In contrast, release of TGF-ß1 from LR-PRP was observed only with activation by AA, not with TBN. Consistent with its inhibitory role in AA signaling, ASA significantly inhibited AA-mediated release of all 3 growth factors measured in this study. Although ASA had no effect on TBN-mediated release of VEGF and TGF-ß1 from LR-PRP, ASA did partially block TBN-mediated release of PDGF-AB, although the mechanism remains unclear. CONCLUSION: Daily use of low-dose ASA reduces VEGF, PDGF-AB, and TGF-ß1 expression in freshly isolated human LR-PRP when activated with AA. CLINICAL RELEVANCE: Reduction in growth factor release attributed to daily use of low-dose ASA or other COX inhibitors can be mitigated when PRP samples are activated with TBN. Clinical studies are needed to determine whether activation before PRP injection is needed in all applications where ASA is in use and to what extent ASA may inhibit growth factor release in vivo at the site of injury.