Tiffany N. Castillo

Comparison of Growth Factor and Platelet Concentration From Commercial Platelet-Rich Plasma Separation Systems

Background: Clinical studies claim that platelet-rich plasma (PRP) shortens recovery times because of its high concentration of growth factors that may enhance the tissue repair process. Most of these studies obtained PRP using different separation systems, and few analyzed the content of the PRP used as treatment. Purpose: This study characterized the composition of single-donor PRP produced by 3 commercially available PRP separation systems. Study Design: Controlled laboratory study. Methods: Five healthy humans donated 100 mL of blood, which was processed to produce PRP using 3 PRP concentration systems (MTF Cascade, Arteriocyte Magellan, Biomet GPS III). Platelet, white blood cell (WBC), red blood cell, and fibrinogen concentrations were analyzed by automated systems in a clinical laboratory, whereas ELISA determined the concentrations of platelet-derived growth factor αβ and ββ (PDGF-αβ, PDGF-ββ), transforming growth factor β1 (TGF-β1), and vascular endothelial growth factor (VEGF). Results: There was no significant difference in mean PRP platelet, red blood cell, active TGF-β1, or fibrinogen concentrations among PRP separation systems. There was a significant difference in platelet capture efficiency. The highest platelet capture efficiency was obtained with Cascade, which was comparable with Magellan but significantly higher than GPS III. There was a significant difference among all systems in the concentrations of WBC, PDGF-αβ, PDGF-ββ, and VEGF. The Cascade system concentrated leukocyte-poor PRP, compared with leukocyte-rich PRP from the GPS III and Magellan systems. Conclusion: The GPS III and Magellan concentrate leukocyte-rich PRP, which results in increased concentrations of WBCs, PDGF-αβ, PDGF-ββ, and VEGF as compared with the leukocyte-poor PRP from Cascade. Overall, there was no significant difference among systems in the platelet concentration, red blood cell, active TGF-β1, or fibrinogen levels. Clinical Relevance: Products from commercially available PRP separation systems produce differing concentrations of growth factors and WBCs. Further research is necessary to determine the clinical relevance of these findings.

Prospective Correlation Between Serum Relaxin Concentration and Anterior Cruciate Ligament Tears Among Elite Collegiate Female Athletes

Background: The female anterior cruciate ligament may be more susceptible to injury than the male anterior cruciate ligament because of the gender-specific expression of receptors for relaxin, a collagenolytic hormone that promotes remodeling of the anterior cruciate ligament. Purpose: This study was undertaken to investigate whether collegiate female athletes with elevated serum relaxin concentrations (SRC) sustain anterior cruciate ligament tears at an increased rate compared with those with lower SRC. Study Design: Cohort study (prognosis); Level of evidence, 2. Methods: From 2005 to 2010, 143 Division I female athletes from 2 universities participating in sports at high risk for anterior cruciate ligament tears (basketball, lacrosse, field hockey, soccer, gymnastics, and volleyball) were recruited to participate. Questionnaires and urine luteinizing hormone (LH) tests were used to determine participants’ anterior cruciate ligament injury and menstrual history and to identify their mid-luteal phase or projected cycle days 21 to 24. Serum samples were obtained for progesterone and relaxin ELISA (enzyme-linked immunosorbent assay) analysis. Participants were monitored for anterior cruciate ligament injury over their 4-year National Collegiate Athletic Association athletic career. Results: A total of 128 participants completed the study and were eligible for data analysis. The cumulative incidence of complete anterior cruciate ligament tear over the 4-year study period was 21.9%, and varied significantly by sport (P < .001). The mean SRC for athletes with anterior cruciate ligament tears (6.0 ± 8.1 pg/mL) was significantly higher than that for those without anterior cruciate ligament tears (1.8 ± 3.4 pg/mL; P = .013). In subgroup analysis of the 46 athletes who had detectable SRC, the cumulative incidence of anterior cruciate ligament tear was 14 of 46 (30.4%); the mean SRC among athletes with anterior cruciate ligament tears (14 of 46) was 12.1 ± 7.7 pg/mL and without anterior cruciate ligament tears (32 of 46), 5.7 ± 3.6 pg/mL (P = .002). When 6.0 pg/mL was set as the SRC cutoff for screening athletes for risk of anterior cruciate ligament tear in the subgroup with detectable relaxin levels, the test had 71% sensitivity, 69% specificity, 52% positive predictive value, 88% negative predictive value, and a relative risk of 4.4. These values were significant by χ2 test (P = .003) and receiver operating characteristic analysis (P = .002). Conclusion: Elite female athletes with anterior cruciate ligament tears have higher SRC than those without tears. Those with an SRC greater than 6.0 pg/mL had over 4 times increased risk for a tear. Clinical Relevance: Females with higher serum relaxin levels may be at increased risk for anterior cruciate ligament tears. Further investigation of the clinical utility of SRC testing is warranted.

Trends in serum relaxin concentration among elite collegiate female athletes

Purpose: This study was designed to investigate the relationship between serum relaxin concentration (SRC) and menstrual history and hormonal contraceptive use among elite collegiate female athletes. Evaluation of SRC in athletes is necessary, because relaxin has been associated with increased knee joint laxity and decreased anterior cruciate ligament (ACL) strength in animal models. Methods: National Collegiate Athletic Association Division I female athletes participating in sports at high risk for ACL tears – basketball, field hockey, gymnastics, lacrosse, soccer, and volleyball – were invited to participate. All participants completed a questionnaire about their menstrual history and hormonal contraceptive use. Venipuncture was performed to obtain samples of serum progesterone and relaxin. Samples were obtained during the mid-luteal phase from ovulating participants, and between the actual or projected cycle days 21 to 24, from anovulatory participants. Serum concentration of relaxin and progesterone was determined by ELISA and the data were analyzed using SPSS statistical software with significance set at P = 0.05. Results: 169 female athletes participated. The mean SRC among all participants was 3.08 ± 6.66 pg/mL). The mean SRC differed significantly between those participants using hormonal contraceptives (1.41 pg/mL) and those not using hormonal contraceptives (3.08 pg/mL, P = 0.002). Mean SRC was lowest among amenorrheic participants (1.02 pg/mL) and highest among oligomenorrheic participants (3.71 pg/mL) and eumenorrheic participants (3.06 pg/mL); these differences were not significant (P = 0.53). Mean serum progesterone concentration (SPC) differed significantly between those participants using hormonal contraceptives (2.80 ng/mL), and those not using hormonal contraceptives (6.99 ng/mL, P < 0.0001). Conclusions: There is a positive correlation between serum progesterone and SRC and an attenuation of SRC with hormonal contraceptive use. Our results underscore the significant role that hormonal contraceptives can play in decreasing relaxin levels, if future investigations establish a link between relaxin levels and ligamentous injury among female athletes.

Comparison of Longitudinal Open Incision and Two-Incision Techniques for Carpal Tunnel Release

PURPOSE This study analyzes the long-term postoperative symptoms and functional outcomes of patients who underwent either traditional open (single-incision) or 2-incision carpal tunnel release (CTR). Because 2-incision CTR preserves the superficial nerves and subcutaneous tissue between the thenar and hypothenar eminences, it may account for fewer postoperative symptoms and improved functional recovery. METHODS A retrospective chart review identified patients who underwent either open or 2-incision CTR for isolated carpal tunnel syndrome between 2005 and 2008 by a single surgeon. Patients with a history of hand trauma or confounding comorbidities were excluded. We mailed a Disabilities of the Arm, Shoulder, and Hand (DASH) Questionnaire and a Brigham and Womens Carpal Tunnel Questionnaire (BWCTQ) to all eligible participants. Data from the completed questionnaires were analyzed using independent t-tests and Pearsons correlation. Significance was set at p = .05. RESULTS A total of 82 patients (106 hands; 27 men and 55 women; mean age, 60.5 y) were eligible to participate. Of these, 51 patients (63 hands; 20 men and 31 women; mean age, 61.1 y) responded (62% response rate). The mean duration of follow-up was 22 months (range, 12-37 mo; SD 7.3 mo). The 2-incision group mean BWCTQ Symptom Severity Scale score (1.13, SD 0.25) was significantly lower than the open group mean Symptom Severity Scale score (1.54, SD 0.70, p = .001). The 2-incision group mean BWCTQ Functional Status Scale score (1.24, SD 0.51) was significantly lower than the open group mean Functional Status Scale score (1.71, SD 0.76, p = .008). The 2-incision group mean DASH score (5.10, SD 12.03) was significantly lower than the open group mean DASH score (16.28, SD 19.98, p = .01). CONCLUSIONS Patients treated with 2-incision CTR reported statistically significantly less severe long-term postoperative symptoms and improved functional status compared with patients treated with traditional open CTR. Future prospective studies with objective measures are needed to further investigate the difference in outcomes found between these 2 CTR techniques. TYPE OF STUDY/LEVEL OF EVIDENCE Therapeutic III.

The biomechanical significance of washer use with screw fixation.

Objectives: Washers can be used with lag screws during fracture fixation to optimize compression and minimize the risk of unintentional intrusion of the screw head through cortical bone during screw insertion. The concept of using washers to optimize screw fixation is particularly applicable to iliosacral screw fixation and screw fixation of the femoral neck, distal femur, as well as the proximal and distal tibia. However, there is a paucity of literature on this topic. The purpose of this study was to detail the biomechanical consequences of washer use and screw intrusion. Methods: Partially threaded 7.0-mm cannulated screws with and without washers were placed through synthetic bone blocks fabricated to simulate cortical and cancellous bone. A load cell was used to measure the compressive force before and after screw intrusion. Screws were tested with a washer (n = 8), without a washer (n = 8), and with a washer after initially being intruded (n = 8). Results: Screws inserted with washers generated significantly more compressive force than screws inserted without washers before screw intrusion. After intrusion, compressive force decreased significantly under all conditions, but screws inserted with washers maintained greater compressive force than screws inserted without washers. Screws with washers reinserted after intrusion without a washer, produced almost as much compressive force as screws inserted with washers primarily. Conclusions: Screw intrusion during fracture fixation results in a loss of compressive force that may compromise fixation quality. Washers are advantageous in that they allow for more compression to be generated before intrusion occurs and can be used to salvage compressive force of intruded screws.

Bilateral sacral ala fractures are strongly associated with lumbopelvic instability

Objectives: To quantify the incidence of lumbopelvic instability in the setting of unilateral and bilateral sacral fractures and assess whether the presence of bilateral sacral fractures on axial imaging is a useful screening test for lumbopelvic instability. Design: Retrospective case series. Setting: Level I trauma center at an academic medical center. Patients/Participants: A hospital database was used to identify patients diagnosed with a sacral fracture by The International Classification of Diseases, Ninth Revision (ICD-9) code from 2000 to 2014. Intervention: Axial cross-sectional imaging was reviewed to confirm the presence of unilateral or bilateral sacral ala fractures. Sagittal reconstructions were scrutinized for a transverse fracture line separating the lumbar spine from the pelvis, which was used to define lumbopelvic instability. Main Outcome Measurements: The Roy-Camille classification system was applied to all identified cases of lumbopelvic instability. Results: One thousand five hundred twenty-six patients were diagnosed with sacral fractures by the ICD-9 code. Four hundred ninety had adequate axial and sagittal cross-sectional imaging. Four hundred forty-three of these patients had unilateral sacral ala fractures, and none of these were associated with lumbopelvic instability. Forty-seven patients had bilateral sacral ala fractures, and 41 of these (87%) had a transverse component indicating some degree of lumbopelvic instability. The presence of bilateral sacral fractures was 100% sensitive and 99% specific for lumbopelvic instability. Among fractures with lumbopelvic instability, 27 (66%) were Roy-Camille type 1, 11 (27%) were type 2, and 3 (7%) were type 3. Conclusions: Bilateral sacral ala fractures are strongly associated with lumbopelvic instability and can be used as a very sensitive and specific screening tool. All patients with bilateral sacral fractures on axial computed tomography or magnetic resonance imaging should have close assessment of the sagittal plane images to evaluate for this pathology. Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Total Knee Arthroplasty for the Young, Active Patient with Osteoarthritis

The demographic profile and expectations of patients with tricompartmental knee osteoarthritis who are seeking surgical treatment have shifted over the past several decades. Patients today tend to be younger and more active and seek rapid recovery, while also demand return to high-performance activities and optimal durability characteristics of their total knee components. Consequently, it is critical that surgeons understand the performance and survivability of total knee arthroplasty (TKA) in the young patient and appropriately counsel patients about postoperative expectations for pain relief, function, and durability.