Cells Remain Viable When Collected With an In-Line-Suction Tissue Collector From Byproducts of Anterior Cruciate Ligament Reconstruction Surgery.

Purpose: To investigate the viability of cells collected with an in-line-suction autologous tissue collector from the tissue byproducts of arthroscopic anterior cruciate ligament (ACL) reconstruction, to characterize cells from different tissue types, and to identify mesenchymal stem cells. Methods: Patients aged 14 to 50 years with ACL injuries requiring arthroscopic reconstruction surgery were offered enrollment and screened for participation. In total, 12 patients were enrolled in the descriptive laboratory study. Arthroscopic byproduct tissue was collected with an in-line-suction autologous tissue collector from 4 intraoperative collection sites for each patient: ACL stump, ACL fat pad, notchplasty debris, and tunnel drilling debris. All tissue samples were digested using collagenase, and the derived cellular populations were analyzed in vitro, characterizing cellular viability, proliferative potential, qualitative multipotent differentiation capacity, and cell-surface marker presence. Results: An equivalent mass of arthroscopic byproduct tissue was taken from each of the 4 intraoperative collection sites (1.12-1.61 g, P = .433), which all showed an average viability of at least 99.95% and high average total nucleated cells (≥1.37 × 107 cells/mL). No significant differences in collected mass (P = .433), cellular viability (P = .880), or total nucleated cells (P = .692) were observed between the 4 byproduct tissues. The byproduct tissues did exhibit significant differences in monocyte (P = .037) and red blood cell (P = .038) concentrations, specifically with greater values present in the ACL stump tissue. Cells from all byproduct tissues adhered to plastic cell culture flasks. Significant differences were found between colony-forming unit fibroblast counts of the 4 byproduct tissues when plated at 106 (P = .003) and 103 (P = .016) cells as the initial seeding density. There was a significant relationship found between both the starting concentration (χ2 = 32.7, P < .001) and the byproduct tissue type (χ2 = 30.4, P < .001) to the presence of ≥80% confluency status at 10 days. Cells obtained from all 4 byproduct tissues qualitatively showed positive tri-lineage (adipocyte, osteoblast, chondroblast) differentiation potential compared with negative controls under standardized in vitro differentiation conditions. Cells derived from all 4 byproduct tissues expressed cell-surface antigens CD105+, CD73+, CD90+, CD45-, CD14-, and CD19- (>75%), and did not express CD45 (<10%). There were no statistically significant differences in cell-surface antigens between the four byproduct tissues. Conclusions: This descriptive laboratory study demonstrated that cells derived from arthroscopic byproduct tissues of ACL reconstruction remain viable when collected with an in-line-suction autologous tissue collector and these cells meet the ISCT criteria to qualify as mesenchymal stem cells. Clinical Relevance: It is known that viable mesenchymal stem cells reside in byproduct tissue of anterior cruciate ligament reconstruction surgery (ACLR). Practical methods to harvest these cells at the point of care require further development. This study validates the use of an in-line-suction autologous tissue collector for the harvest of viable mesenchymal stem cells after ACLR.

Osteochondral Regeneration in the Knee Joint with Autologous Peripheral Blood Stem Cells plus Hyaluronic Acid after Arthroscopic Subchondral Drilling: Report of Five Cases.

BACKGROUND: Treatment of osteochondral defects (OCDs) of the knee joint remains challenging. The purpose of this study was to evaluate the clinical and radiological results of osteochondral regeneration following intra-articular injections of autologous peripheral blood stem cells (PBSC) plus hyaluronic acid (HA) after arthroscopic subchondral drilling into OCDs of the knee joint. CASE PRESENTATION: Five patients with OCDs of the knee joint are presented. The etiology includes osteochondritis dissecans, traumatic knee injuries, previously failed cartilage repair procedures involving microfractures and OATS (osteochondral allograft transfer systems). PBSC were harvested 1 week after surgery. Patients received intra-articular injections at week 1, 2, 3, 4, and 5 after surgery. Then at 6 months after surgery, intra-articular injections were administered at a weekly interval for 3 consecutive weeks. These 3 weekly injections were repeated at 12, 18 and 24 months after surgery. Each patient received a total of 17 injections. Subjective International Knee Documentation Committee (IKDC) scores and MRI scans were obtained preoperatively and postoperatively at serial visits. At follow-ups of >5 years, the mean preoperative and postoperative IKDC scores were 47.2 and 80.7 respectively (p = 0.005). IKDC scores for all patients exceeded the minimal clinically important difference values of 8.3, indicating clinical significance. Serial MRI scans charted the repair and regeneration of the OCDs with evidence of bone growth filling-in the base of the defects, followed by reformation of the subchondral bone plate and regeneration of the overlying articular cartilage. CONCLUSION: These case studies showed that this treatment is able to repair and regenerate both the osseous and articular cartilage components of knee OCDs.

A Tensionable and Retensionable Knotless Anchor Repair Construct for Compression After Reduction of Tibial Avulsion Fracture of Anterior Cruciate Ligament.

Tibial avulsion fractures comprise a subset of anterior cruciate ligament injuries. Primary fixation methods have traditionally used either screw or suture fixation. New anchor and suture technologies have led to the development of tensionable and retensionable techniques. These newer techniques allow for not only anatomic reduction but also further compression after reduction. The purpose of this technical note is to introduce a tensionable and retensionable construct that uses knotless anchor fixation to produce compression after anatomic reduction of a tibial avulsion fracture.

Screening for Femoral Head Osteonecrosis Following COVID-19: Is It Worth It?

Objectives: Based on WHO data, as of June 2022, there were 532.2 million confirmed COVID-19 cases globally. In the initial phase of the COVID -19 pandemic, patients experiencing critical illness marked by severe respiratory distress were commonly subjected to corticosteroid treatment. Regrettably, the administration of exogenous corticosteroids stands as the prevailing cause of ONFH. In the current narrative review, we aim to evaluate if active screening should be utilized to diagnose post-COVID-19 ONFH in its early stages. Methods: The databases for PubMed, CINAHL, and Science Direct were systematically queried in March 2022. The search terms were as follows: "COVID-19", "severe acute respiratory syndrome", "coronavirus", "systemic steroid", "corticosteroid", "femoral head osteonecrosis", "avascular necrosis", or "steroid therapy." The included studies for review were all required to be peer-reviewed studies in the English language with Reported complications linked to steroid therapy in COVID-19 patients or potential connections to the development of ONFH in individuals recovering from the novel coronavirus have been documented. Results: Systemic corticosteroids were frequently employed in managing critically ill COVID-19 patients. The CDC reports up to June 2022 showed more than 4.8 million COVID-19 hospitalizations in the US, with approximately over one million patients receiving steroids. In a study of ONFH after infection with COVID-19, all patients had bilateral involvement. The average duration from the initiation of corticosteroid treatment to the onset of symptoms was 132.8 days. Conclusion: In summary, a distinct correlation exists between the administration of steroids to individuals with COVID-19 and the subsequent risk of ONFH. Moreover, an elevated dosage and prolonged duration of steroid therapy in COVID-19 patients are associated with an increased likelihood of developing ONFH. Therefore, active screening for high-risk patients, that may have received systemic corticosteroid treatment during a COVID-19 illness, may be reasonable.

Augmentation of ACL Autograft Reconstruction With an Amnion Collagen Matrix Wrap and Bone Marrow Aspirate Concentrate: A Pilot Randomized Controlled Trial With 2-Year Follow-up.

Background: It is theorized that the lack of a synovial lining after anterior cruciate ligament (ACL) injury and ACL reconstruction (ACLR) contributes to slow ligamentization and possible graft failure. Whether graft maturation and incorporation can be improved with the use of a scaffold requires investigation. Purpose: To evaluate the safety and efficacy of wrapping an ACL autograft with an amnion collagen matrix and injecting bone marrow aspirate concentrate (BMAC), quantify the cellular content of the BMAC samples, and assess 2-year postoperative patient-reported outcomes. Study Design: Randomized controlled trial; Level of evidence, 2. Methods: A total of 40 patients aged 18 to 35 years who were scheduled to undergo ACLR were enrolled in a prospective single-blinded randomized controlled trial with 2 arms based on graft type: bone-patellar tendon-bone (BTB; n = 20) or hamstring (HS; n = 20). Participants in each arm were randomized into a control group who underwent standard ACLR or an intervention group who had their grafts wrapped with an amnion collagen matrix during graft preparation, after which BMAC was injected under the wrap layers after implantation. Postoperative magnetic resonance imaging (MRI) mapping/processing yielded mean T2* relaxation time and graft volume values at 3, 6, 9, and 12 months. Participants completed the Single Assessment Numeric Evaluation Score, Knee injury and Osteoarthritis Outcome Score, and pain visual analog scale. Statistical linear mixed-effects models were used to quantify the effects over time and the differences between the control and intervention groups. Adverse events were also recorded. Results: No significant differences were found at any time point between the intervention and control groups for BTB T2* (95% CI, -1.89 to 0.63; P = .31), BTB graft volume (95% CI, -606 to 876.1; P = .71), HS T2* (95% CI, -2.17 to 0.39; P = .162), or HS graft volume (95% CI, -11,141.1 to 351.5; P = .28). No significant differences were observed between the intervention and control groups of either graft type on any patient-reported outcome measure. No adverse events were reported after a 2-year follow-up. Conclusion: In this pilot study, wrapping a graft with an amnion collagen matrix and injecting BMAC appeared safe. MRI T2* values and graft volume of the augmented ACL graft were not significantly different from that of controls, suggesting that the intervention did not result in improved graft maturation. Registration: NCT03294759 (ClinicalTrials.gov identifier).

Editorial Commentary: Elbow Injury Results When Pediatric and Adolescent Throwing Athletes Throw as Hard as Possible, and Weighted Baseball Training Should Be Banned for Youth Athletes.

We are in the middle of an epidemic involving pediatric and adolescent throwing athletes. Too many young athletes have elbow injuries, and it is unnerving how young surgical indications can present. Increased competition has led to increased demands before athletes have reached their full adult size. Evidence shows that higher ball velocity, higher shoulder external rotation angle, and higher arm speed are associated with increased medial elbow torque and elbow injury in this population. Pediatric and adolescent athletes should not try to throw as hard as possible, and weighted baseball training should be banned for youth athletes.

Regulatory and Ethical Aspects of Orthobiologic Therapies.

Orthobiologic therapies show significant promise to improve outcomes for patients with musculoskeletal pathology. There are considerable research efforts to develop strategies that seek to modulate the biological environment to promote tissue regeneration and healing and/or provide symptomatic relief. However, the regulatory pathways overseeing the clinical translation of these therapies are complex, with considerable worldwide variation. The introduction of novel biologic treatments into clinical practice raises several ethical dilemmas. In this review, we describe the process for seeking approval for biologic therapies in the United States, Europe, and Japan. We highlight a number of ethical issues raised by the clinical translation of these treatments, including the design of clinical trials, monitoring outcomes, biobanking, "off-label" use, engagement with the public, marketing of unproven therapies, and scientific integrity.

Blood Flow Restriction Using a Pneumatic Tourniquet Is Not Associated With a Cellular Systemic Response.

Purpose: The purpose of this study was to determine the effects of blood flow restriction (BFR) using a pneumatic tourniquet on CD34+ cells, platelets, white blood cells, neutrophils, lymphocytes, lactate, and glucose compared with standard exercise. Methods: Fifteen healthy volunteers (8 males and 7 females, 28.6 ± 3.6 years old) who were able to perform the exercise sessions on a VersaClimber participated. Participants were randomized to undergo an experimental (EXP) occluded testing session using the pneumatic tourniquets on all 4 extremities and a control (CON) session. The exercise protocol concluded after 9 minutes or when participants reached a rating of perceived exertion of 20. Blood draws were performed before testing and immediately after the exercise session. Blood analysis consisted of complete blood counts as well as flow cytometry to measure peripheral CD34+ counts as a marker for hematopoietic progenitor cells (HPCs). Results: A significant increase from before to after exercise values was observed in both the EXP and CON groups with CD34+, WBC counts, platelets, and lymphocytes; however, no differences existed between EXP and CON groups for any variable. CD34+ increased in the EXP (3.1 ± 1.6 vs. 4.3 ± 1.8 cells · L-1; P < .001) and CON (3.3 ± 1.9 vs. 4.4 ± 1.4 cells · L-1; P < .001) sessions. White blood cells also significantly increased in both the EXP (7.8 ± 1.4 vs. 11.8 ± 2.5 K · L-1 K · L-1; P < .001) and CON (7.5 ± 1.8 vs. 11.3 ± 3.0 K · L-1; P < .001) sessions. Platelets also increased in both the EXP (258.6 ± 52.5 vs. 309.9 ± 52.7 K · L-1; P < .001) and CON (263.1 ± 44.7 vs. 316.1 ± 43.9 K · L-1; P < .001) sessions, and conversely, a significant decrease in the average neutrophil counts in the EXP (mean difference = -13.7%; P < .001) and CON (mean difference = -13.2%; P < .001) sessions was observed. Lymphocyte counts in the EXP (mean difference = 22.8%; P < .001) and CON (mean difference = 19.3%; P < .001) sessions increased significantly. Conclusions: There were no significant differences in systemic cellular responses when undergoing aerobic-based exercise with and without a pneumatic tourniquet system. Level of Evidence: 2, prospective comparative study.

Bone Marrow Aspirate Concentrate Is Equivalent to Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis at 2 Years: A Prospective Randomized Trial.

BACKGROUND: Autologous platelet-rich plasma (PRP) and bone marrow aspirate concentrate (BMC) are being used clinically as therapeutic agents for the treatment of knee osteoarthritis. PURPOSE/HYPOTHESIS: The purpose of this study was to compare the efficacy of BMC and PRP on pain and function in patients with knee osteoarthritis up to 24 months after injection. It was hypothesized that patients receiving BMC would have better sustained outcomes than those receiving PRP. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: A total of 90 participants aged between 18 and 80 years with symptomatic knee osteoarthritis (Kellgren-Lawrence grades 1-3) were randomized into 2 study groups: PRP and BMC. Both groups completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and subjective International Knee Documentation Committee (IKDC) questionnaire before and 1, 3, 6, 9, 12, 18, and 24 months after a single intra-articular injection of leukocyte-rich PRP or BMC. A linear mixed-effects model was performed to quantify the effects over time and the difference between the groups. This model has the random effect for time to assess the extent in which the change over time differs from one person to another. RESULTS: An overall 84 patients completed questionnaires from baseline to 12 months; however, 17 patients (n = 9; PRP group) were lost to follow-up at 18 months and 25 (n = 13; PRP group) at 24 months. There were no statistically significant differences in IKDC (P = .909; 95% CI, -6.26 to 7.03) or WOMAC (P = .789; 95% CI, -6.26 to 4.77) scores over time between the groups. Both groups had significantly improved IKDC (P < .001; 95% CI, 0.275-0.596) and WOMAC (P = .001; 95% CI, -0.41 to -0.13) scores from baseline to 24 months after the injection. These improvements plateaued at 3 months and were sustained for 24 months after the injection, with no difference between PRP and BMC at any time point. CONCLUSIONS: For the treatment of osteoarthritis, PRP and BMC performed similarly out to 24 months. BMC was not superior to PRP. REGISTRATION: NCT03289416 (ClincalTrials.gov identifier).

The safety and efficacy of 2 anterior-inferior portals for arthroscopic repair of anterior humeral avulsion of the glenohumeral ligament: cadaveric comparison.

BACKGROUND: Humeral avulsion of the glenohumeral ligament (HAGL) lesions are associated with shoulder instability. Arthroscopic repair of anterior HAGL lesions typically requires the placement of an anterior-inferior (5-o'clock) portal, with different variations of this portal described. The purpose of this study was to determine the efficacy of described anterior-inferior shoulder arthroscopy portals for arthroscopic anterior HAGL repair, as well as evaluate the safety of these portals with respect to the surrounding neurovascular structures. Additionally, we sought to evaluate the effect of arm adduction vs. standard abduction during anterior-inferior portal creation. METHODS: HAGL lesions were created and repaired using an all-arthroscopic technique in 12 cadaveric shoulders (matched pairs). Half of the repairs were performed using a standard 5-o'clock portal, whereas the other half of the matched pairs were repaired using a medialized 5-o'clock portal. Repairs were timed, and the number of anchor pullouts was recorded. The shoulders were subsequently dissected to measure the proximity of the portal to the cephalic vein, musculocutaneous nerve, axillary nerve, and lateral cord of the brachial plexus. RESULTS: The average time for HAGL repair was 18.0 ± 4.6 minutes. Repair times using the medial 5-o'clock portal (19.0 ± 3.3 minutes) vs. standard 5-o'clock portal (16.2 ± 5.8 minutes) were not significantly different (P = .37). From abduction to adduction, the cephalic vein distance from the standard 5-o'clock portal increased from 4.1 ± 4.7 mm to 5.2 ± 5.4 mm (P = .02); musculocutaneous nerve distance, from 14.4 ± 9.8 mm to 18.1 ± 10.8 mm (P = .005); axillary nerve distance, from 19.2 ± 9.6 mm to 19.8 ± 9.2 mm (P = .12); and distance of the lateral cord of the brachial plexus, 13.8 ± 6.6 mm to 16.7 ± 6.4 mm (P = .0006). CONCLUSIONS: The arm abduction angle significantly affects the distance of the cephalic vein, musculocutaneous nerve, and lateral cord of the brachial plexus from the anterior-inferior portal, regardless of which portal-standard or medial 5-o'clock portal-is chosen. This portal should be created with the arm in adduction. Arthroscopic HAGL repair can be performed safely, although accurate anchor placement remains a challenge. There was no advantage to use of the medial 5-o'clock portal. With a curved guide, the standard 5-o'clock portal allows for reproducible anchor placement and is recommended for anterior HAGL repairs.

Cellular Augmentation of Anterior Cruciate Ligament Surgery Is Not Currently Evidence Based: A Systematic Review of Clinical Studies.

PURPOSE: To perform a systematic review of clinical outcome studies exploring cellular augmentation of anterior cruciate ligament (ACL) surgery, including stem cell techniques. METHODS: A systematic search was performed according to the Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) guidelines using the Cochrane, PubMed, MEDLINE, SPORTDiscus, and CINAHL (Cumulative Index to Nursing and Allied Health Literature) databases from 2000 to 2019. The inclusion criteria were clinical studies that reported on ACL surgery augmented with stem cells or cellular therapy and patient-reported outcome measures or graft healing. Risk of bias was assessed using the Cochrane risk-of-bias tool for randomized clinical trials, and nonrandomized trials were assessed using the Methodological Items for Non-randomized Studies (MINORS) tool. Methodologic assessment was performed according to the Modified Coleman Methodology Score. RESULTS: Four studies were found: 2 randomized clinical trials, 1 cohort study with a matched historical control group, and 1 case series. The mean Modified Coleman Methodology Score in these studies was 59, and there was a low risk of bias in 1 study. One study reported outcomes of augmented ACL repair, and 3 studies reported the results of augmented ACL reconstruction. Cellular therapies varied and included concentrated bone marrow aspirate, collagenase/centrifuge processed adipose, and marrow stimulation combined with platelet-rich plasma, as well as cells cultured from allograft bone marrow aspirate. The concentrated bone marrow aspirate and adipose tissue study results did not support their use. The marrow stimulation technique combined with repair led to promising clinical results. The use of allograft cultured cells improved patient-reported outcomes and postoperative radiographic findings. CONCLUSIONS: Augmentation of ACL surgery with cellular therapy is not supported by clinical evidence at this time. LEVEL OF EVIDENCE: Level IV.

Concentrated Bone Marrow Aspirate Is More Cellular and Proliferative When Harvested From the Posterior Superior Iliac Spine Than the Proximal Humerus.

PURPOSE: The purpose of this study is to determine whether concentrated bone marrow aspirate (cBMA) from the posterior superior iliac spine (PSIS) or proximal humerus (PH) produces a more productive cellular harvest in patients undergoing arthroscopic rotator cuff repair. METHODS: Patients under 80 years old undergoing surgery for arthroscopic rotator cuff repair were enrolled. Two 60 mL aliquots of BMA were harvested from each subject, one from the PSIS and one from the PH. Each aliquot was processed independently to create cBMA. Cellular composition was determined using an automated hemocytometer and proliferative potential was studied with colony forming unit (CFU) assays. RESULTS: Twelve patients were recruited (7 male, 5 female). The average age was 64.3 years (range 46.1-77.25 years) with body mass index of 26.8 (range 20.0-34.3). The average total nucleated cells (TNC) from PH was 18.7 × 106 cells/mL (95% confidence interval [CI], 4.4-33.0; standard deviation [SD], 24.8) with 3.9 CFU/mL (95% CI, 0.3-7.5, SD, 5.7). The average TNC count from the PSIS was 55.9 × 106 cells/mL (95% CI, 25.3-86.4; SD, 52.9) with 32.5 CFU/mL (95% CI, 11.5-53.5; SD, 33.1). The PSIS had a 3.0 times greater total nucleated cell yield (P = .014) and 8.3 times greater number of CFU/mL (P = .024) when compared to the PH. The average harvest time from the PSIS was 5.6 minutes and from the PH was 11.0 minutes (P = .043); harvest time did not account for additional time to prep and drape the PSIS. CONCLUSIONS: The cBMA harvested from the PSIS resulted in a 3.0 times greater cellular yield and an 8.3 times greater proliferative product than cBMA from the PH. CLINICAL RELEVANCE: When a more cellular cBMA product is sought to augment rotator cuff tear repair surgery, the PSIS is the preferred site for harvest.

Association Between Passive Hip Range of Motion and Pitching Kinematics in High School Baseball Pitchers.

BACKGROUND: Limitations in passive hip range of motion (PROM) may negatively affect pitching mechanics in baseball pitchers. Understanding the relationships between PROM and mechanics can assist in the development of injury prevention protocols. PURPOSE: The purpose of this study was to examine the association of hip rotational PROM with pelvis and trunk rotation during pitching in high school baseball pitchers. Study Design: Cross-sectional. METHODS: Twenty-five healthy high school baseball pitchers volunteered (15.9 ± 1.1 years; 180.4 ± 5.5 cm; 75.4 ± 9.3 kg). Seated passive hip internal rotation (IR) and external rotation (ER) PROM were measured using a digital inclinometer. Total PROM was calculated (IR+ER). Pitching biomechanical data were collected with a 3-dimensional electromagnetic tracking system while pitchers threw fastballs. Simple linear regressions were performed to examine the association between hip IR, ER, and total PROM with pitching kinematics at foot contact including stride length, pelvis rotation, and trunk rotation. RESULTS: Only one significant association in PROM and kinematics was observed. Drive leg hip IR PROM was associated with trunk rotation angle [F(1,24) = 4.936, p = 0.036], with an R2 = 0.177. Drive leg total PROM was not associated trunk rotation angle [F(1,24) = 4.144, p = 0.053] with an R2 = 0.153. CONCLUSIONS: Increased drive leg hip IR PROM was associated with decreased trunk rotation towards home plate. Hip total PROM and ER were not related to pitching mechanics. LEVEL OF EVIDENCE: 2.

Platelet-Rich Plasma: Fundamentals and Clinical Applications.

Platelet-rich plasma (PRP) is perhaps the most widely studied of the biologic therapies, with an ever-growing body of evidence supporting its safety and efficacy in decreasing inflammation and pain and promoting healing in the setting of both nonoperative and operative treatments. PRP is produced by the centrifugation of whole blood, isolating its constituent parts based on their unique densities. These density gradients can be selectively harvested so as to obtain different concentrations of various blood product components, such as platelets and leukocytes. A precise and consistent method for describing the essential characteristics of different PRP formulations is critical for both practical and research purposes. The concentration of platelets, method of activation, and the total number of red blood cells (RBCs), white blood cells (WBCs), and neutrophils relative to baseline values are all of particular importance in accurately describing a PRP formulation. The biologic activity of PRP is manifold: platelet α granules promote the release of various growth factors, including vascular endothelial growth factor and tissue growth factor ß, while inflammation is modulated through inhibition of the nuclear factor-κB pathway. PRP has been convincingly shown to be efficacious in the setting of patellar tendinopathies, knee osteoarthritis, and lateral epicondylitis. In fact, several recent randomized controlled trials have demonstrated the superiority of PRP over both corticosteroids and hyaluronic acid in treating knee OA-related symptoms. There is also substantial promise for the utility of PRP in treating partial hamstring tears and as an adjunct to rotator cuff (RC) repair, especially in the setting of small- to medium-sized tears, where it appears to exert substantial analgesic effects and promote enhanced rates of RC repair healing.

Editorial Commentary: Point-of-Care Harvest and Application of Resident Stem Are Practical and Cost-Effective.

Point-of-care harvest and application of residence stem cells are practical and cost-effective. Tissue formerly considered waste contains these biologically potent cells, and use of such tissue may represent a big part of biologics going forward. The practical application of orthobiologics has slowed because of 3 hurdles: the regulatory requirements of stem cell technologies; the energy, time, and money required to develop a clinical evidence base; and the expense that they present to patients and institutions. Orthobiologic technologies that are simple and cheap and that leverage tissues that are already readily available at the point of care (i.e., the surgical procedure) solve many of these challenges. Cell sources could include knee synovium, shoulder subacromial bursa, bone marrow aspirate, and anterior cruciate ligament injury effusion fluid and stump tissue. A current concern is that collagenase processing and culture expansion are steps resulting in regulatory hurdles in the United States.

Favorable Reoperation Rate at 2 Years Following Repair of Horizontal Cleavage Tears Using an All Suture-Based Technique: A Prospective, Multicenter Trial.

PURPOSE: This prospective, multicenter trial evaluates the clinical success (as measured by reoperation rates and improvements in patient-reported outcome measures) of using circumferential compression stitches with all-suture techniques for horizontal cleavage tears (HCTs) of the meniscus. METHODS: Investigators enrolled 30 patients (mean age, 38.2 years; standard deviation, 11.1 years) aged 18 to 60 years with HCTs in the symptomatic compartment at 8 centers in the United States who underwent HCT repair with all-suture circumferential stitches using a self-retrieving all-inside suture passing device. Postoperative follow-up visits were conducted at 6 months, 1 year, and 2 years. Study outcomes included freedom from reoperation of the index meniscus repair site; knee pain and function, as measured by International Knee Documentation Committee Knee evaluation (IKDC), Knee injury and Osteoarthritis Outcome Score, Lysholm Knee Scale, and Tegner Activity Scale; and serious complications observed during the study. Minimal clinically important difference at 1 year was assessed for IKDC and Lysholm. RESULTS: Twenty-three patients had 2-year follow-up data available. Freedom from reoperation was 96.0% at 6 months (26/27, 91.7% at 1 year [23/25], and 82.6% at 2 years [19/23]). Significant improvement was observed in over baseline at 2 years for IKDC (36.7-82.5; P < .001), Knee injury and Osteoarthritis Outcome Score (52.2-89.3; P < .001), Lysholm (50.2-87.4; P < .001), and Tegner scores (3.3-5.3; P = .007). Minimal clinically important difference was met or exceeded for IKDC and Lysholm scores at 1 year 69.2% and 65.4% of patients, respectively. Four patients (6.7%) experienced serious complications, of which 2 were assessed as being related to the procedure. CONCLUSIONS: Repair of HCTs using all-suture circumferential stitches placed with a self-retrieving all-inside suture passing device leads to a favorable reoperation rate (17.4%), significant improvements in clinical outcomes, and an acceptable rate of serious complications (6.7%) at 2 years, supporting the viability of this treatment approach in this indication. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Arthroscopic Subchondral Drilling Followed by Injection of Peripheral Blood Stem Cells and Hyaluronic Acid Showed Improved Outcome Compared to Hyaluronic Acid and Physiotherapy for Massive Knee Chondral Defects: A Randomized Controlled Trial.

PURPOSE: The purpose of this study was to evaluate the safety and efficacy of intra-articular injections of autologous peripheral blood stem cells (PBSCs) plus hyaluronic acid (HA) after arthroscopic subchondral drilling into massive chondral defects of the knee joint and to determine whether PBSC therapy can improve functional outcome and reduce pain of the knee joint better than HA plus physiotherapy. METHODS: This is a dual-center randomized controlled trial (RCT). Sixty-nine patients aged 18 to 55 years with International Cartilage Repair Society grade 3 and 4 chondral lesions (size ≥3 cm2) of the knee joint were randomized equally into (1) a control group receiving intra-articular injections of HA plus physiotherapy and (2) an intervention group receiving arthroscopic subchondral drilling into chondral defects and postoperative intra-articular injections of PBSCs plus HA. The coprimary efficacy endpoints were subjective International Knee Documentation Committee (IKDC) and Knee Injury and Osteoarthritis Outcome Score (KOOS)-pain subdomain measured at month 24. The secondary efficacy endpoints included all other KOOS subdomains, Numeric Rating Scale (NRS), and Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) scores. RESULTS: At 24 months, the mean IKDC scores for the control and intervention groups were 48.1 and 65.6, respectively (P < .0001). The mean for KOOS-pain subdomain scores were 59.0 (control) and 86.0 (intervention) with P < .0001. All other KOOS subdomain, NRS, and MOCART scores were statistically significant (P < .0001) at month 24. Moreover, for the intervention group, 70.8% of patients had IKDC and KOOS-pain subdomain scores exceeding the minimal clinically important difference values, indicating clinical significance. There were no notable adverse events that were unexpected and related to the study drug or procedures. CONCLUSIONS: Arthroscopic marrow stimulation with subchondral drilling into massive chondral defects of the knee joint followed by postoperative intra-articular injections of autologous PBSCs plus HA is safe and showed a significant improvement of clinical and radiologic scores compared with HA plus physiotherapy. LEVEL OF EVIDENCE: Level I, RCT.

Biologic Association Annual Summit: 2020 Report.

Interest and research in biologic approaches for tissue healing are exponentially growing for a variety of musculoskeletal conditions. The recent hype concerning musculoskeletal biological therapies (including viscosupplementation, platelet-rich plasma, and cellular therapies, or "stem cells") is driven by several factors, including demand by patients promising regenerative evidence supported by substantial basic and translational work, as well as commercial endeavors that complicate the scientific and lay understanding of biological therapy outcomes. While significant improvements have been made in the field, further basic and preclinical research and well-designed randomized clinical trials are needed to better elucidate the optimal indications, processing techniques, delivery, and outcome assessment. Furthermore, biologic treatments may have potential devastating complications when proper methods or techniques are ignored. For these reasons, an association comprising several scientific societies, named the Biologic Association (BA), was created to foster coordinated efforts and speak with a unified voice, advocating for the responsible use of biologics in the musculoskeletal environment in clinical practice, spearheading the development of standards for treatment and outcomes assessment, and reporting on the safety and efficacy of biologic interventions. This article will introduce the BA and its purpose, provide a summary of the 2020 first annual Biologic Association Summit, and outline the future strategic plan for the BA.

Elevation of Peripheral Blood CD34+ and Platelet Levels After Exercise With Cooling and Compression.

PURPOSE: To analyze the cellular response and chemokine profiles following exercise using cooling and blood flow restriction on the Vasper system. METHODS: Healthy male patients between the ages of 20 and 39 years were recruited. Testing was performed on the Vasper system, a NuStep cross-trainer with concomitant 4-limb venous compression with proximal arm cuffs at 40 mm Hg and proximal leg cuffs at 65 mm Hg. A cooling vest and cooling mat (8.3°C) were used. A 7-minute warm-up followed by alternating 30- and 60-second sprints with 1.5 and 2 minutes of active recovery, respectively, between each sprint. Peripheral blood was drawn before exercise, immediately following exercise (T20), 10 minutes after the first post-exercise blood draw (T30), and then every 30 minutes (T60, T90, T120, T150, T180). A blood draw occurred at 24 hours' postexercise. Complete blood count, monoclonal flow cytometry for CD34+, and enzyme-linked immunosorbent assay were used to analyze the samples. RESULTS: Sixteen healthy male patients (29.5 ± 4.5years, 1.78 ± 0.05m, 83.7 ± 11.4 kg) were enrolled. There was an immediate, temporary increase in white blood cell counts, marked by an increase in lymphocyte differential (38.3 ± 6.5 to 44.3 ± 9.0%, P = .001), decrease in neutrophil differential (47.8 ± 6.6 to 42.0 ± 9.1%, P < .001), and platelets (239.5 ± 57.2 to 268.6 ± 86.3 K⋅µL-1, P = .01). Monocytes significantly decreased from PRE to T90 (9.8 ± 1.1 to 8.9 ± 1.1K/µL, P < .001) and T120 (8.9 ± 1.1 K/µL, P < .0001). There was a significant increase in CD34+ cells (3.9 ± 2.0 to 5.3 ± 2.8 cells⋅µL-1, P < .001). No detectable differences in measured cytokine levels of interleukin (IL)-10, IL-6, granulocyte-macrophage colony-stimulating factor , IL-1ra, tumor necrosis factor-α, or IL-2 were observed. CONCLUSIONS: A significant elevation of peripheral blood CD34+ and platelet levels immediately following the exercise session was observed; however, there was no effect on peripheral circulation of IL-10, IL-6, IL-1ra, tumor necrosis factor-α, or IL-2. CLINICAL RELEVANCE: Exercise can be considered as a way to manipulate point-of-care blood products like platelet-rich plasma and may increase product yield.

Mobilized Peripheral Blood Stem Cells are Pluripotent and Can Be Safely Harvested and Stored for Cartilage Repair.

PURPOSE: The primary objective of this study was to reproduce and validate the harvest, processing and storage of peripheral blood stem cells for a subsequent cartilage repair trial, evaluating safety, reliability, and potential to produce viable, sterile stem cells. METHODS: Ten healthy subjects (aged 19-44 years) received 3 consecutive daily doses of filgrastim followed by an apheresis harvest of mononuclear cells on a fourth day. In a clean room, the apheresis product was prepared for cryopreservation and processed into 4 mL aliquots. Sterility and qualification testing were performed pre-processing and post-processing at multiple time points out to 2 years. Eight samples were shipped internationally to validate cell transport potential. One sample from all participants was cultured to test proliferative potential with colony forming unit (CFU) assay. Five samples, from 5 participants were tested for differentiation potential, including chondrogenic, adipogenic, osteogenic, endoderm, and ectoderm assays. RESULTS: Fresh aliquots contained an average of 532.9 ± 166. × 106 total viable cells/4 mL vial and 2.1 ± 1.0 × 106 CD34+ cells/4 mL vial. After processing for cryopreservation, the average cell count decreased to 331.3 ± 79. × 106 total viable cells /4 mL vial and 1.5 ± 0.7 × 106 CD34+ cells/4 mL vial CD34+ cells. Preprocessing viability averaged 99% and postprocessing 88%. Viability remained constant after cryopreservation at all subsequent time points. All sterility testing was negative. All samples showed proliferative potential, with average CFU count 301.4 ± 63.9. All samples were pluripotent. CONCLUSIONS: Peripheral blood stem cells are pluripotent and can be safely harvested/stored with filgrastim, apheresis, clean-room processing, and cryopreservation. These cells can be stored for 2 years and shipped without loss of viability. CLINICAL RELEVANCE: This method represents an accessible stem cell therapy in development to augment cartilage repair.