Most Orthopaedic Platelet-Rich Plasma Investigations Don't Report Protocols and Composition: An Updated Systematic Review.

PURPOSE: To systematically review the literature to assess the heterogeneity of platelet-rich plasma (PRP) preparation and composition reporting for the treatment of musculoskeletal/orthopaedic pathologies. METHODS: A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to identify Level I and Level II studies from 2016 to 2022 that evaluated the use of PRP therapy for musculoskeletal pathologies. The search phrase used was "platelet-rich plasma clinical studies." Studies were assessed based on their reporting of the PRP preparation methods and reporting of PRP composition. RESULTS: One hundred twenty-four studies (in 120 articles) met inclusion criteria for analysis. Of these studies, 15 (12.1%) provided comprehensive reporting, including a clear, well-described, and reproducible preparation protocol that future investigators can follow. Thirty-three studies (26.6%) quantitatively reported the final PRP product composition. CONCLUSIONS: Among the studies using PRP for the treatment of musculoskeletal/orthopaedic pathologies, less than 20% provided a clear, well-described, and reproducible PRP preparation protocol, and only one-fourth of studies reported on the final PRP product composition. CLINICAL RELEVANCE: A diverse current reporting of PRP composition between studies provides a high heterogeneity of the term "PRP," which becomes a limitation for a comparison of studies using PRP.

Experts Achieve Consensus on a Majority of Statements Regarding Platelet-Rich Plasma Treatments for Treatment of Musculoskeletal Pathology.

PURPOSE: To establish consensus statements on platelet-rich plasma (PRP) for the treatment of musculoskeletal pathologies. METHODS: A consensus process on the treatment of PRP using a modified Delphi technique was conducted. Thirty-five orthopaedic surgeons and sports medicine physicians participated in these consensus statements on PRP. The participants were composed of representatives of the Biologic Association, representing 9 international orthopaedic and musculoskeletal professional societies invited due to their active interest in the study of orthobiologics. Consensus was defined as achieving 80% to 89% agreement, strong consensus was defined as 90% to 99% agreement, and unanimous consensus was indicated by 100% agreement with a proposed statement. RESULTS: There was consensus on 62% of statements about PRP. CONCLUSIONS: (1) PRP should be classified based on platelet count, leukocyte count, red blood count, activation method, and pure-plasma versus fibrin matrix; (2) PRP characteristics for reporting in research studies are platelet count, leukocyte count, neutrophil count, red blood cell count, total volume, the volume of injection, delivery method, and the number of injections; (3) the prognostic factors for those undergoing PRP injections are age, body mass index, severity/grade of pathology, chronicity of pathology, prior injections and response, primary diagnosis (primary vs postsurgery vs post-trauma vs psoriatic), comorbidities, and smoking; (4) regarding age and body mass index, there is no minimum or maximum, but clinical judgment should be used at extremes of either; (5) the ideal dose of PRP is undetermined; and (6) the minimal volume required is unclear and may depend on the pathology. LEVEL OF EVIDENCE: Level V, expert opinion.

Editorial Commentary: Cartilage Restoration Typically Requires Joint Optimization as Well as Local Cartilage Resurfacing to Achieve Best Outcomes: The 30,000 Foot View.

Successful resurfacing of the articular surface often requires surgical optimization of the joint environment, in addition to the cartilage restoration procedure. This is the 30,000-foot view theory, where surgical planning concentrates on changing the forces in the joint that may have led to the cartilage lesion by performing essential procedures, such as osteotomies; scar tissue releases and/or ligament lengthening; joint stabilization; or meniscus replacement. With this view, which cartilage procedure should I perform becomes a secondary question. This approach involves looking at the environment of the joint as a whole and can lead to improved outcomes. Recent research shows that treatment of bipolar cartilage lesions results in inferior outcomes compared with unipolar lesions. But experience shows that results may be improved when treating bipolar lesions by using a structural graft on one surface, such as an osteochondral allograft, and a cellular or particulate graft on the opposite surface rather than using two nonstructural grafts. Before the transplantation, the surgeon corrects the joint forces as a whole. Over the past 10 years, I have consistently seen the benefits of cartilage restoration procedures using techniques anywhere from autologous cellular grafts to large, structural osteochondral allografts. Finally, the 30,000 foot view also includes addressing modifiable patient factors, such as weight loss. For the most part, the results have been promising, achieving significantly improved patient response rates, defined as a minimal clinically important difference (or MCID).

Acromioclavicular Joint Injuries in Sport.

ABSTRACT: Sport-related shoulder injuries, including disruptions to the acromioclavicular joint (ACJ), are common. An ACJ injury is classified by the degree and direction of the clavicle displacement. Although the diagnosis can be made clinically, standard radiographic views are important to determine the severity of the ACJ disruption and assess for concurrent injuries. The majority of ACJ injuries can be managed nonoperatively; however, surgical treatment is indicated in some cases. Long-term outcomes are generally favorable for most ACJ injuries, and athletes generally return to sport without functional limitations. This article provides an in-depth discussion regarding all aspects of ACJ injuries, including clinically relevant anatomy, biomechanics, evaluation, treatment, and complications.

Platelet-Rich Plasma Versus Hyaluronic Acid for Hip Osteoarthritis Yields Similarly Beneficial Short-Term Clinical Outcomes: A Systematic Review and Meta-analysis of Level I and II Randomized Controlled Trials.

PURPOSE: To systematically review the literature to compare the efficacy of platelet-rich plasma (PRP) and hyaluronic acid (HA) injections for the treatment of hip osteoarthritis (OA). METHODS: A systematic review was performed by searching PubMed, the Cochrane Library, and Embase to identify randomized controlled trials that compared the clinical efficacy of PRP and HA injections for hip OA. The search phrase used was hip, osteoarthritis, platelet-rich plasma, hyaluronic acid, randomized. Patients were assessed based on the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), the Visual Analog Scale (VAS) for pain, and the Harris Hip Score (HHS). Subanalyses were performed for any outcome score in which ≥3 studies reported results. RESULTS: Six studies (5 level I, 1 level II) met inclusion criteria, including 211 patients undergoing intra-articular injection with PRP (mean age 60.0 years, mean follow-up 12.2 months) and 197 patients with HA (mean age 62.3 years, mean follow-up 11.9 months). No significant differences were found in the weighted improvement of any outcome score (WOMAC, VAS, or HHS) from preinjection to postinjection between groups. When excluding a study with the highest risk of bias to eliminate heterogeneity, pooled subanalysis demonstrated no significant differences in WOMAC subscores between PRP and HA groups. Similarly, in a pooled subanalysis that isolated patients treated with leukocyte-poor PRP, no significant differences in WOMAC subscores were found between PRP and HA groups. CONCLUSION: Patients undergoing treatment for hip OA with either PRP or HA injections can expect to experience similarly beneficial short-term clinical outcomes. LEVEL OF EVIDENCE: II, systematic review of level I and II studies.

Nonsurgical Management of Osteoarthritis of the Knee: What You Should Be Injecting Now and in the Future.

Osteoarthritis of the knee affects many Americans. With the aging of the population and increasing comorbidities (eg, obesity, diabetes, hypertension, heart disease), the use of oral or topical NSAIDs is often contraindicated. Injectable treatment options are advantageous because of the ability to decrease or avoid the unwanted systematic adverse effects of NSAIDs. Injectable treatment options for osteoarthritis of the knee go back to the 1950s, beginning with corticosteroids, which remain widely used despite concerns that they may have adverse effects on articular chondrocytes and short duration of efficacy. The recent (FDA approval in 2017) introduction of a sustained-release corticosteroid (triamcinolone acetonide extended-release) offers significantly longer benefit than standard cortisone products and with substantially lower concentration levels of chondrocyte exposure to the steroid. Hyaluronic acid was added to the options for intra-articular injection in osteoarthritis of the knee in the late 1990s and remains widely used despite some controversy over its efficacy. Although guidelines for the use of hyaluronic acid for management of osteoarthritis of the knee have varied widely, careful analysis of the data and patient's perceived efficacy indicate its continued and important role in managing osteoarthritis of the knee. Finally, the past 15 years have seen an explosion in the use of biologics including platelet-rich plasma and pluripotential (often termed stem) cells. The science behind their use and efficacy is evolving and continued study is warranted.

Tranexamic Acid Use in Knee and Shoulder Arthroscopy Leads to Improved Outcomes and Fewer Hemarthrosis-Related Complications: A Systematic Review of Level I and II Studies.

PURPOSE: To systematically review the literature to compare the efficacy and safety of tranexamic acid (TXA) as a means to minimize hemarthrosis-related complications after arthroscopic procedures of the knee, hip, and shoulder. METHODS: A systematic review according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed by searching PubMed, Cochrane Library, and Embase databases to locate randomized controlled trials comparing the clinical outcomes and postoperative complications of patients undergoing arthroscopy with and without TXA. Search terms used were "tranexamic acid," "arthroscopy," "knee," "hip," and "shoulder." Patients were evaluated based on early (<6 weeks) postoperative signs of hemarthrosis using the Coupens and Yates classification, postoperative complications (myocardial infarction, stroke, venous thromboembolism events), range of motion (ROM), and patient-reported outcome scores (Visual analog scale, Subjective International Knee Documentation Committee, Lysholm, and Tegner activity scores). RESULTS: Five studies (2 level I and 3 level II) met inclusion criteria, including a total of 299 patients undergoing arthroscopy with TXA and 299 patients without TXA. The average follow-up duration for all patients was 43.9 days. Procedures performed were partial meniscectomy, anterior cruciate ligament reconstruction, and rotator cuff repair. No studies evaluating TXA use in hip arthroscopy were identified. Coupens-Yates hemarthrosis grades significantly improved in the TXA groups across all studies. Three studies found TXA patients to experience significantly less postoperative pain at latest follow-up, 1 study found TXA patients to have significantly better postoperative Lysholm scores, and 1 study found TXA patients to have significantly more ROM at latest follow-up compared with non-TXA patients (P < .05). CONCLUSION: Patients undergoing arthroscopy, particularly arthroscopic meniscectomy, arthroscopic-assisted anterior cruciate ligament reconstruction, and arthroscopic rotator cuff repair, with TXA can be expected to experience improved outcomes and less hemarthrosis-related complications in the early postoperative period compared with non-TXA patients. LEVEL OF EVIDENCE: II, systematic review of level I and II studies.

Effects of unloader bracing on clinical outcomes and articular cartilage regeneration following microfracture of isolated chondral defects: a randomized trial.

PURPOSE: To determine whether the use of an unloading brace can increase the thickness of cartilage regenerate after microfracture surgery. METHODS: This is a randomized (1:1) controlled clinical trial. Twenty-four patients who underwent microfracture between 2012 and 2015 were identified and were randomly assigned to an unloading brace group or a no-brace group. All patients were kept non-weight bearing for the first eight weeks after surgery and then patients in the intervention group began using an unloading brace for an average of 63.9 (SD = 41.6) days to protect clot stability by exerting a varus or valgus force on the knee to decrease the force on the knee's lateral or medial compartment, respectively. Quality of the cartilage repair was assessed with knee magnetic resonance imaging to determine repair tissue thickness (primary outcome), repair tissue volume, and T2 relaxation times at 12 and 24 months after surgery. Clinical outcomes were evaluated with KOOS, Tegner, SF12, and Lysholm questionnaires at six, 12 and 24 months after surgery. RESULTS: Three patients were lost to follow-up, resulting in 21 patients ultimately analyzed. The unloading brace repair tissue was greater than the no-brace group in volume (26.8 ± 23.7 mm3 vs - 8.4 ± 22.7 mm3, p = 0.005) and thickness (0.2 ± 0.2 mm versus - 0.4 ± 0.3 mm, p = 0.001) at 12 months and in cartilage thickness in the unloading brace group at 24 months (0.4 ± 0.4 mm versus - 0.1 ± 0.3 mm, p = 0.029). There was a positive correlation between wearing the brace longer and improved 6-month KOOS symptom scores (r = 0.82, p = 0.013), 6-month KOOS QOL scores (r = 0.80, p = 0.017), 6-month Tegner scores (r = 0.94, p = 0.002), and Tegner score changes from baseline to 6 months (r = 0.80, p = 0.032). CONCLUSION: This study found a significant mid-term increase in cartilage repair tissue thickness following unloading bracing in patients recovering from microfracture for isolated chondral defects. LEVEL OF EVIDENCE: II.

T2 relaxation times of knee cartilage in 109 patients with knee pain and its association with disease characteristics.

Background and purpose - Quantitative T2 mapping MRI of cartilage has proven value for the assessment of early osteoarthritis changes in research. We evaluated knee cartilage T2 relaxation times in a clinical population with knee complaints and its association with patients and disease characteristics and clinical symptoms.Patients and methods - In this cross-sectional study, T2 mapping knee scans of 109 patients with knee pain who were referred for an MRI by an orthopedic surgeon were collected. T2 relaxation times were calculated in 6 femoral and tibial regions of interest of full-thickness tibiofemoral cartilage. Its associations with age, sex, BMI, duration of complaints, disease onset (acute/chronic), and clinical symptoms were assessed with multivariate regression analysis. Subgroups were created of patients with abnormalities expected to cause predominantly medial or lateral tibiofemoral cartilage changes.Results - T2 relaxation times increased statistically significantly with higher age and BMI. In patients with expected medial cartilage damage, the medial femoral T2 values were significantly higher than the lateral; in patients with expected lateral cartilage damage the lateral tibial T2 values were significantly higher. A traumatic onset of knee complaints was associated with an acute elevation. No significant association was found with clinical symptoms.Interpretation - Our study demonstrates age, BMI, and type of injury-dependent T2 relaxation times and emphasizes the importance of acknowledging these variations when performing T2 mapping in a clinical population.

Quantitation of progenitor cell populations and growth factors after bone marrow aspirate concentration.

BACKGROUND: The number of Mesenchymal Stem/Stromal Cells (MSCs) in the human bone marrow (BM) is small compared to other cell types. BM aspirate concentration (BMAC) may be used to increase numbers of MSCs, but the composition of MSC subpopulations and growth factors after processing are unknown. The purpose of this study was to assess the enrichment of stem/progenitor cells and growth factors in BM aspirate by two different commercial concentration devices versus standard BM aspiration. METHODS: 120 mL of BM was aspirated from the iliac crest of 10 male donors. Each sample was processed simultaneously by either Emcyte GenesisCS® (Emcyte) or Harvest SmartPReP2 BMAC (Harvest) devices and compared to untreated BM aspirate. Samples were analyzed with multicolor flow cytometry for cellular viability and expression of stem/progenitor cells markers. Stem/progenitor cell content was verified by quantification of colony forming unit-fibroblasts (CFU-F). Platelet, red blood cell and total nucleated cell (TNC) content were determined using an automated hematology analyzer. Growth factors contents were analyzed with protein quantification assays. Statistical analyses were performed by ANOVA analysis of variance followed by Tukey's multiple comparison test or Wilcoxon matched-pairs signed rank test with p < 0.05 for significance. RESULTS: Cell viability after processing was approximately 90% in all groups. Compared to control, both devices significantly enriched TNCs and platelets, as well as the CD45-CD73+ and CD45-CD73+CD90+ cell populations. Further, Harvest significantly concentrated CD45-CD10+, CD45-CD29+, CD45-CD90+, CD45-CD105+, CD45-CD119+ cells, and CD45dimCD90+CD271+ MSCs, whereas Emcyte significantly enriched CD45dimCD44+CD271+ MSCs. BM concentration also increased the numbers of CFU-F, platelet-derived growth factor, vascular endothelial growth factor, macrophage colony-stimulating factor, interleukin-1b, VCAM-1 and total protein. Neither system concentrated red blood cells, hematopoietic stem cells or bone morphogenetic proteins. CONCLUSION: This data could contribute to the development of BMAC quality control assays as both BMAC systems concentrated platelets, growth factors and non-hematopoietic stem cell subpopulations with distinct phenotypes without loss of cell viability when compared to unprocessed BM.

Editorial Commentary: The Use of Allogenic Cells in Regenerative Medicine: Are Amniotic, Umbilical, and Other Allogenic Cell Sources Safe?

There are abundant data to suggest that the autologous transplantation of human progenitor cells is safe. However, the use of allogenic cells for human use has not been adequately researched and should not be considered safe at this time.

Single-stage revision anterior cruciate ligament reconstruction using bone grafting for posterior or widening tibial tunnels restores stability of the knee and improves clinical outcomes.

PURPOSE: Revision ACL surgery may be complicated by tunnel malposition and/or tunnel widening and often requires a staged treatment approach that includes bone grafting, a period of several months to allow bone graft incorporation and then definitive revision ACL reconstruction. The purpose of this study was to evaluate the results of a single-staged ACL revision reconstruction technique using a cylindrical dowel bone graft for patients who have existing posteriorly placed and/or widened tibial tunnels in the tibia at a minimum of 2 years follow-up. METHODS: Between 2010 and 2014, patients undergoing single-stage revision ACL reconstruction with the described technique were prospectively enrolled and evaluated. At a minimum of 24 months, patients were evaluated by physical examination, multiple clinical outcome instruments including KOOS, Tegner and Lysholm, and preoperative and postoperative MRIs. RESULTS: At a mean of 35.1 months, 18 consecutive patients had no revision surgery and no subjective knee instability. There were statistically significant improvements in the Tegner (median 2, interquartile range 2.25; p < 0.01), Lysholm (20.0 ± 15.0; p < 0.01), KOOS symptoms scale (12.9 ± 11.8; p < 0.01), KOOS pain scale (15.4 ± 18.7; p < 0.01), KOOS ADL scale (13.5 ± 19.0; p < 0.01), KOOS sports scale (32.8 ± 26.4; p < 0.01), and KOOS QoL scale (18.1 ± 16.9; p < 0.01). Postoperative MRI demonstrated statistically significant anteriorization of the tibial tunnel and a statistically significant decrease in tunnel widening. CONCLUSION: Revision ACL reconstruction utilizing a single-staged tibial tunnel grafting technique resulted in improved knee pain, function, and stability at a minimum of 24-month follow-up. LEVEL OF EVIDENCE: IV.

The use of biologics for the elbow: a critical analysis review.

There is significant interest in biologic treatment options to improve the healing environment and more rapidly decrease symptoms in many conditions around the elbow. Despite fairly widespread use of biologic agents such as platelet-rich plasma (PRP) in the elbow, there is a lack of clear evidence in the literature to support its use. The potential impact of these biologic agents must be evaluated with evidence from high-quality studies, particularly considering the high financial burden these treatments often impose on patients. The aim of this review is to provide an evidence-based summary of the biologic augmentation options available for use by the physician treating painful conditions of the elbow and to identify areas where further research is warranted.

Two Genetic Variants Associated with Plantar Fascial Disorders.

Plantar fascial disorder is comprised of plantar fasciitis and plantar fibromatosis. Plantar fasciitis is the most common cause of heel pain, especially for athletes involved in running and jumping sports. Plantar fibromatosis is a rare fibrous hyperproliferation of the deep connective tissue of the foot. To identify genetic loci associated with plantar fascial disorders, a genome-wide association screen was performed using publically available data from the Research Program in Genes, Environment and Health including 21,624 cases of plantar fascial disorders and 80,879 controls. One indel (chr5:118704153:D) and one SNP (rs62051384) showed an association with plantar fascial disorders at genome-wide significance (p<5×10-8) with small effects (odds ratios=0.93 and 1.07 per allele, respectively). The indel chr5:118704153:D is located within TNFAIP8 (encodes a protein induced by TNF alpha) and rs62051384 is located within WWP2 (which is involved in proteasomal degradation). These DNA variants may be informative in explaining why some individuals are at higher risk for plantar fascial disorders than others.

Quality Measures in Orthopaedic Sports Medicine: A Systematic Review.

PURPOSE: To report the current quality measures that are applicable to orthopaedic sports medicine physicians. METHODS: Six databases were searched with a customized search term to identify quality measures relevant to orthopaedic sports medicine surgeons: MEDLINE/PubMed, EMBASE, the National Quality Forum (NQF) Quality Positioning System (QPS), the Agency for Healthcare Research and Quality (AHRQ) National Quality Measures Clearinghouse (NQMC), the Physician Quality Reporting System (PQRS) database, and the American Academy of Orthopaedic Surgeons (AAOS) website. Results were screened by 2 Board-certified orthopaedic surgeons with fellowship training in sports medicine and dichotomized based on sports medicine-specific or general orthopaedic (nonarthroplasty) categories. Hip and knee arthroplasty measures were excluded. Included quality measures were further categorized based on Donabedian's domains and the Center for Medicare and Medicaid (CMS) National Quality Strategy priorities. RESULTS: A total of 1,292 quality measures were screened and 66 unique quality measures were included. A total of 47 were sports medicine-specific and 19 related to the general practice of orthopaedics for a fellowship-trained sports medicine specialist. Nineteen (29%) quality measures were collected within PQRS, with 5 of them relating to sports medicine and 14 relating to general orthopaedics. AAOS Clinical Practice Guidelines (CPGs) comprised 40 (60%) of the included measures and were all within sports medicine. Five (8%) additional measures were collected within AHRQ and 2 (3%) within NQF. Most quality measures consist of process rather than outcome or structural measures. No measures addressing concussions were identified. CONCLUSIONS: There are many existing quality measures relating to the practice of orthopaedic sports medicine. Most quality measures are process measures described within PQRS or AAOS CPGs. CLINICAL RELEVANCE: Knowledge of quality measures are important as they may be used to improve care, are increasingly being used to determine physician reimbursement, and can inform future quality measure development efforts.

Two Genetic Loci associated with Medial Collateral Ligament Injury.

Medial collateral ligament (MCL) injuries are a common knee injury, especially in competitive athletes. Identifying genetic loci associated with MCL injury could shed light on its etiology. A genome-wide association screen was performed using data from the Research Program in Genes, Environment and Health (RPGEH) including 1 572 cases of MCL injury and 100 931 controls. 2 SNPs (rs80351309 and rs6083471) showed an association with MCL injury at genome-wide significance (p<5×10-8) with moderate effects (odds ratios=2.12 and 1.57, respectively). For rs80351309, the genotypes were imputed with only moderate accuracy, so this SNP should be viewed with caution until its association with MCL injury can be validated. The SNPs rs80351309 and rs6083471 show a statistically significant association with MCL injury. It will be important to replicate this finding in future studies.

A Genetic Marker Associated with Shoulder Dislocation.

Shoulder dislocations are common shoulder injuries associated with athletic activity in contact sports, such as football, rugby, wrestling, and hockey. Identifying genetic loci associated with shoulder dislocation could shed light on underlying mechanisms for injury and identify predictive genetic markers. To identify DNA polymorphisms associated with shoulder dislocation, a genome-wide association screen was performed using publically available data from the Research Program in Genes, Environment and Health including 662 cases of shoulder dislocation and 82 602 controls from the European ancestry group. rs12913965 showed an association with shoulder dislocation at genome-wide significance (p=9.7×10-9; odds ratio=1.6) from the European ancestry group. Individuals carrying one copy of the risk allele (T) at rs12913965 showed a 69% increased risk for shoulder dislocation in our cohort. rs12913965 is located within an intron of the TICRR gene, which encodes TOPBP1 interacting checkpoint and replication regulator involved in the cell cycle. rs12913965 is also associated with changes in expression of the ISG20 gene, which encodes an antiviral nuclease induced by interferons. This genetic marker may one day be used to identify athletes with a higher genetic risk for shoulder dislocation. It will be important to replicate this finding in future studies.

The efficacy of post-operative devices following knee arthroscopic surgery: a systematic review.

PURPOSE: There is a wide array of device modalities available for post-operative treatment following arthroscopic knee surgery; however, it remains unclear which types and duration of modality are the most effective. This systematic review aimed to investigate the efficacy of device modalities used following arthroscopic knee surgery. METHODS: A systematic search of the literature was performed on: PubMed; Scopus; MEDLINE; EMBASE; PEDro; SportDiscus; and CINAHL databases (1995-2015) for clinical trials using device modalities following arthroscopic knee surgery: cryotherapy, continuous passive motion (CPM), neuromuscular electrical stimulation (NMES), surface electromyographic (sEMG) biofeedback and shockwave therapy (ESWT). Only level 1 and 2 studies were included and the methodological quality of studies was evaluated using Physiotherapy Evidence Database (PEDro) scores. Outcome measures included: muscle strength, range of motion, swelling, blood loss, pain relief, narcotic use, knee function evaluation and scores, patient satisfaction and length of hospital stay. RESULTS: Twenty-five studies were included in this systematic review, nineteen of which found a significant difference in outcomes. For alleviating pain and decreasing narcotic consumption following arthroscopic knee surgery, cryocompression devices are more effective than traditional icing alone, though not more than compression alone. CPM does not affect post-operative outcomes. sEMG biofeedback and NMES improve quadriceps strength and overall knee functional outcomes following knee surgery. There is limited evidence regarding the effects of ESWT. CONCLUSION: Cryotherapy, NMES and sEMG are recommended for inclusion into rehabilitation protocols following arthroscopic knee surgery to assist with pain relief, recovery of muscle strength and knee function, which are all essential to accelerate recovery. CPM is not warranted in post-operative protocols following arthroscopic knee surgery because of its limited effectiveness in returning knee range of motion, and additional studies are required to investigate the effects of ESWT. LEVEL OF EVIDENCE: II.

Differences in ACL biomechanical risk factors between field hockey and lacrosse female athletes.

PURPOSE: Previous investigations have revealed a greater incidence of anterior cruciate ligament (ACL) injuries in female lacrosse versus field hockey players. Lacrosse is played in an upright posture with overhead throwing and catching, while field hockey is almost exclusively played in a crouched, forward-flexed position. Biomechanical factors, including decreased knee, hip, and trunk flexion angles, have been identified as risk factors for ACL injury. The purpose of this study was to assess ACL biomechanical risk factors in female field hockey and lacrosse players to determine whether sport-specific posture might contribute to the increased incidence of ACL injury observed in lacrosse athletes. METHODS: Thirty-one Division I NCAA females from field hockey and lacrosse completed four tasks, three times per leg: bilateral drop jump, single-leg drop jump (SDJ), single-leg jump onto a Bosu ball (SDB), and a 45° anticipated cut. Kinematic and force plate data were used to evaluate knee flexion angle, knee adduction moment, hip flexion angle, and trunk flexion and sway angles. Muscle activity of the lateral hamstrings and vastus lateralis was used to estimate peak hamstring activity and the quadriceps/hamstring ratio at the time of peak quadriceps activity (co-contraction ratio). RESULTS: During the SDJ and SDB, peak knee flexion angles were greater in field hockey compared with lacrosse. During cutting, field hockey players were more flexed at the trunk and had greater trunk sway, compared with the lacrosse players. No significant difference was observed for the co-contraction ratio for any of the tasks. CONCLUSIONS: Decreased knee flexion angle during landing, consistent with sport-specific playing postures, may contribute to the higher incidence of ACL injury in lacrosse players relative to field hockey. Sport-specific training injury prevention programmes may benefit from considering these differences between specialized athletes. LEVEL OF EVIDENCE: II.