Effect of Storage Conditions and Activation on Growth Factor Concentration in Platelet-Rich Plasma

This study aimed to evaluate growth factor concentration in platelet-rich plasma (PRP) (leukocyte-rich PRP) based on storage temperature, duration of storage, and method of activation. PRP samples were stored at 24℃ (room temperature group), 4℃ (refrigerator group), and −70℃ (deep-freezer group). In each temperature, four aliquots were prepared based on the time of analysis (immediately, 1, 3, and 7 days after preparation). After storage, concentrations of platelet-derived growth factor-AA (PDGF-AA), transforming growth factor-β (TGF-β), vascular endothelial growth factor (VEGF), insulin-like growth factor-1 (IGF-1), and fibroblast growth factor-basic (FGF-B) were assessed with/without activation using Quantikine colorimetric sandwich immunoassay kits. PRP was activated with 10% Triton-X for PDGF-AA, VEGF, FGF-B, IGF-1 measurement and sonication for TGF-β1 measurement. Without activation, PDGF-AA concentration was highest on day 7 in the room temperature group. With activation, the concentration of PDGF-AA was constant over the observation period at all temperatures. Without activation, the TGF-β1 concentration remained negligible over the observation period at all temperatures. However, with activation, TGF-β1 gradually increased to its highest concentration on day 7 at all temperatures. Over the observation period, VEGF and IGF-1 concentrations were constant with and without activation at all temperatures. Without activation, FGF-B concentration increased, with the highest concentration observed on day 7 in the deep-freezer group. With activation, FGF-B concentration decreased after day 1 in the room temperature group. Growth factor concentration in PRP differed significantly based on storage temperature, duration of storage, and method of activation. Appropriate storage conditions and activation are important to optimize its effects on desired clinical outcomes. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:777-784, 2020     

Accuracy of EBRA-cup measurements after reconstruction of severe acetabular defects at revision THR

Radiostereometric analysis (RSA) is the most accurate method of measuring component migration using radiographs but is restricted to use in prospective studies. Ein-Bild-Roentgen-analyze (EBRA)-Cup can be used retrospectively, but its accuracy to measure component migration following revision is unknown. This study aimed to determine the accuracy of EBRA-Cup measurements of uncemented acetabular component migration after revision total hip replacement (THR). The secondary aim was to compare the number of cases identified using EBRA-Cup and RSA as having proximally migrated above and below 1 mm at 2 years postoperatively. EBRA-Cup measurements were performed on plain antero-posterior pelvic radiographs taken at the same time as RSA radiographs in a prospective cohort of 53 hips undergoing acetabular revision. At 2 years, the mean difference between the RSA and EBRA-Cup measurements for 17 components used to treat pelvic discontinuity was 0.90 mm, significantly greater than the mean difference of 0.28 mm for 36 components without discontinuity (P = .0001). The mean difference between the RSA and EBRA-Cup measurements at 2 years for hips that were reconstructed with an acetabular component alone, 0.28 mm, was significantly lower than hips that were reconstructed with an acetabular component in combination with an augment and/or cage, 0.74 mm (P = .0005). In conclusion, EBRA-Cup can accurately measure migration of uncemented acetabular components used at revision THR. The presence of pelvic discontinuity, and addition of augments and cages, significantly influenced the accuracy of EBRA-Cup measurements. EBRA-Cup and RSA had good agreement on classification of components that migrated proximally above or below 1 mm at 2 years, with 100% sensitivity, and 87% specificity.     

Micropuncture Access Set Use During Implantation of Totally Implantable Venous Access Device May Reduce Upper Extremity DVT Incidence Among Patients Undergoing Chemotherapy for Colorectal Cancer

Background

The aim of this study was to compare the perioperative outcomes when using a micropuncture access set (MS) to those when using a conventional puncture set (CS) for implantation of totally implantable venous access device (TAVID).

Methods

A total of 314 patients undergoing chemotherapy for colorectal cancer were included between June 2015 and July 2018. Of these, 123 (39.2%) received TAVID implantation using MS and 191 patients (60.8%) received TAVID using CS. Perioperative outcomes and complications were compared between both groups.

Results

Baseline characteristics, including body mass index, American Society of Anesthesiologists score, cardiovascular disease, diabetes mellitus, and hyperlipidemia, were not significantly different between the groups. Postoperative complications occurred in 25 patients (8.0%), and the rate and incidence of venous thrombosis were significantly higher in the CS group. There were no significant differences between the groups in other complications such as the rate of port site infection, deep vein thrombosis, obstruction, catheter dislocation, and skin complications (exposure). No incidence of catheter infection, port rotation, intraoperative bleeding, or pneumothorax was observed in this cohort.

Conclusions

MS is a safe and feasible procedure and results in less thrombosis. MS may play an important role in improving outcomes for the implantation of TAVID.

     

Is a Local Administration of Parathyroid Hormone Effective to Tendon-to-Bone Healing in a Rat Rotator Cuff Repair Model?

To evaluate the effect of local parathyroid hormone (PTH) administration on rotator cuff tendon-to-bone healing in a rat model compared with systemic PTH injection and untreated controls. PTH-alginate scaffold was prepared and sustained release of PTH was confirmed. Bilateral supraspinatus tendon repairs were performed in 39 rats (group 1, supraspinatus repair only; group 2, supraspinatus repair with systemic PTH injection; group 3, supraspinatus repair with local PTH administration via an absorbable scaffold; n = 13 each). Biomechanical (cross-sectional area, mode of failure, load to failure, and ultimate stress: right side) and histological analyses (hematoxylin and eosin stain, Masson's Trichrome stain Picrosirius red stain, Immunohistochemistry for BMP2, PTH1R, ColI, and ColIII: Left side) were performed to evaluate tendon-to-bone healing quality at 8 weeks after repair, and blood test (osteocalcin and procollagen type I N-terminal pro-peptide [PINP] levels) was performed in all rats. There was no intergroup difference in the healing failure rate (p = 0.910) or failure mode (p = 0.585). Biomechanically, subjects in groups 2 and 3 exhibited significantly larger cross-sectional areas and higher ultimate failure loads and ultimate stress than those in group 1 (all p < 0.05); however, no differences were noted between groups 2 and 3 (all p > 0.05). Histologically, groups 2 and 3 exhibited more organized tendon-to-bone interface structures with higher density, parallel orientation, and collagen fiber continuity than group 1 (all p < 0.05 except collagen fiber continuity in group 1 vs. 2); however, no differences in histological parameters between groups 2 and 3 (all p > 0.05). The protein levels of bone morphogenic protein 2, PTH 1 receptor, and collagen I and III and the serum level of PINP were increased in groups 2 and 3 versus group 1 (all p < 0.05) without showing differences between groups 2 and 3 (all p > 0.05). Local PTH administration using an absorbable scaffold improved the biomechanical and histological outcomes of rotator cuff tendon-to-bone healing comparable with systemic PTH injection at 8 weeks after repair in a rat model. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:82–91, 2020