American Journal of Sports Medicine - AJSM

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Medizin, Sportwissenschaft, Sportmedizin / Gesundheit
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0363-5465
jährlich 14 mal
Englisch
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American Journal of Sports Medicine - AJSM

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The American Journal of Sports Medicine, founded in 1972, is the official publication of the American Orthopaedic Society for Sports Medicine. The Journal is published bimonthly by the AOSSM. It contains original articles that have undergone peer review.
Meine Notizen
In Which Arm Position Is a Hill-Sachs Lesion Created? Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 13, Page NP74-NP74, November 2019.
In Which Arm Position Is a Hill-Sachs Lesion Created? Response
The American Journal of Sports Medicine, Volume 47, Issue 13, Page NP74-NP75, November 2019.
The Critical Reader—Confounding
The American Journal of Sports Medicine, .
Society News
The American Journal of Sports Medicine, .
High Risk of Tunnel Convergence in Combined Anterior Cruciate Ligament Reconstruction and Lateral Extra-articular Tenodesis: Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 12, Page NP67-NP68, October 2019.
High Risk of Tunnel Convergence in Combined Anterior Cruciate Ligament Reconstruction and Lateral Extra-articular Tenodesis: Response
The American Journal of Sports Medicine, Volume 47, Issue 12, Page NP68-NP70, October 2019.
Low-Molecular-Weight Heparin for the Prevention of Venous Thromboembolism in Patients Undergoing Knee Arthroscopic Surgery and Anterior Cruciate Ligament Reconstruction: Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 12, Page NP71-NP71, October 2019.
Low-Molecular-Weight Heparin for the Prevention of Venous Thromboembolism in Patients Undergoing Knee Arthroscopic Surgery and Anterior Cruciate Ligament Reconstruction: Response
The American Journal of Sports Medicine, Volume 47, Issue 12, Page NP72-NP72, October 2019.
Corrigendum
The American Journal of Sports Medicine, Volume 47, Issue 12, Page NP73-NP73, October 2019.
We Can Do Better
The American Journal of Sports Medicine, .
Society News
The American Journal of Sports Medicine, .
Is Hip Arthroscopy Effective in Patients With Combined Excessive Femoral Anteversion and Borderline Dysplasia? Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 11, Page NP62-NP62, September 2019.
Is Hip Arthroscopy Effective in Patients With Combined Excessive Femoral Anteversion and Borderline Dysplasia? Response
The American Journal of Sports Medicine, Volume 47, Issue 11, Page NP62-NP63, September 2019.
Coper Classification Early After ACL Rupture Changes With Progressive Neuromuscular and Strength Training and Is Associated With 2-Year Success: Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 11, Page NP64-NP65, September 2019.
Coper Classification Early After ACL Rupture Changes With Progressive Neuromuscular and Strength Training and Is Associated With 2-Year Success: Response
The American Journal of Sports Medicine, Volume 47, Issue 11, Page NP65-NP66, September 2019.
The Need for Minimum Reporting Standards for Studies of “Biologics” in Sports Medicine
The American Journal of Sports Medicine, .
A Case Series of Successful Repair of Articular Cartilage Fragments in the Knee
The American Journal of Sports Medicine, .
Background:It is unclear whether chondral fragments without bone have the potential to heal after fixation. Controversy exists and opinions differ regarding the optimal treatment of chondral defects after pure chondral fracture.Purpose:To determine clinical and radiographic outcomes after internal fixation of traumatic chondral fragments repaired to bone in the knee.Study Design:Case series; Level of evidence, 4.Methods:A retrospective clinical and radiographic evaluation of 10 male patients with a mean age of 14.6 years (range, 10-25 years) at the time of surgery was performed. Eight of 10 patients were skeletally immature. Patients were selected by operating surgeons per the presence of a large displaced pure chondral fragment on magnetic resonance imaging and confirmed on intraoperative inspection. All patients had a diagnosed traumatic displaced pure chondral fracture of the knee (without bone) and underwent internal fixation with minimum 1-year follow-up. Validated patient-reported and surgeon-measured outcomes were collected pre- and postoperatively. All patients were evaluated at a mean 56 months postoperatively.Results:At surgery, the mean defect size that was primarily repaired with the displaced chondral fragment was 1.9 × 2.0 cm. With minimum 1-year follow-up, there were no clinical failures. All 8 patients who had subsequent magnetic resonance imaging follow-up had radiographic evidence of complete healing of the chondral fragment back to bone. At a mean follow-up of 56 months (range, 13-171 months; median, 36 months), patients had a mean International Knee Documentation Committee score of 94.74 (range, 87.4-100), a mean Marx Activity Scale score of 14.4 (range, 8-16), and a mean Tegner Activity Scale score of 7 (range, 5-9). At final follow-up, all patients except 1 returned to sports.Conclusion:The treatment of large traumatic chondral fragments is controversial. In this select series of 10 young patients who underwent primary repair with internal fixation, there were no failures clinically. Patients demonstrated excellent short-term clinical and radiographic results after fixation of these relatively large chondral fragments in the knee.
Society News
The American Journal of Sports Medicine, .
Adductor Canal Block Versus Femoral Nerve Block for Pain Control After Anterior Cruciate Ligament Reconstruction: Case Closed? Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP49-NP49, August 2019.
Adductor Canal Block Versus Femoral Nerve Block for Pain Control After Anterior Cruciate Ligament Reconstruction: Case Closed? Response
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP49-NP50, August 2019.
Ankle Lateral Ligament Augmentation Versus the Modified Broström-Gould Procedure: Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP51-NP51, August 2019.
Ankle Lateral Ligament Augmentation Versus the Modified Broström-Gould Procedure: Response
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP51-NP52, August 2019.
Partial Meniscectomy for Degenerative Medial Meniscal Root Tears Shows Favorable Outcomes in Well-Aligned, Nonarthritic Knees: Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP53-NP54, August 2019.
Partial Meniscectomy for Degenerative Medial Meniscal Root Tears Shows Favorable Outcomes in Well-Aligned, Nonarthritic Knees: Response
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP54-NP57, August 2019.
Should We Rethink How to Define Success After ACL Surgery? Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP58-NP59, August 2019.
Should We Rethink How to Define Success After ACL Surgery? Response
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP59-NP60, August 2019.
Erratum
The American Journal of Sports Medicine, Volume 47, Issue 10, Page NP61-NP61, August 2019.
A Tribute to Billy
The American Journal of Sports Medicine, .
Society News
The American Journal of Sports Medicine, .
Corrigendum
The American Journal of Sports Medicine, Volume 47, Issue 9, Page NP48-NP48, July 2019.
Early Hip Arthroscopy for Femoroacetabular Impingement Syndrome Provides Superior Outcomes When Compared With Delaying Surgical Treatment Beyond 6 Months
The American Journal of Sports Medicine, .
Background:There is literature on the association between chronic preoperative pain and worse outcomes among patients undergoing hip arthroscopy for femoroacetabular impingement syndrome (FAIS). However, there are few data on whether there is an optimum window that provides the best midterm surgical outcomes.Purpose:To assess the outcomes of hip arthroscopy for FAIS according to timing of surgical intervention.Study Design:Cohort study; Level of evidence, 3.Methods:Patients undergoing arthroscopic intervention for FAIS with a minimum 2-year follow-up were included. All patients completed the Hip Outcome Score–Activities of Daily Living (HOS-ADL), Hip Outcome Score–Sport Specific (HOS-SS), modified Harris Hip Score (mHHS), International Hip Outcome Tool–12 (iHOT-12), and visual analog scales for pain and satisfaction. Patients were stratified by preoperative symptom duration. We compared 3 to 6 months of symptoms with other subsequent time frames (>6-12, >12-24, and >24 months). Clinically significant outcome was determined with the minimal clinically important difference and patient acceptable symptomatic state.Results:A total of 1049 patients were included (mean ± SD: age, 32.3 ± 12.4 years; follow-up, 30.8 ± 6.7 months). Patients undergoing surgery at 3 to 6 months of symptoms had no significant differences in outcome when compared with those in the >6- to 12-month group except for the iHOT-12 (P = .028). Patients with symptom duration of >12 to 24 months and >24 months had worse outcomes across all measures (P < .001). Surgery within 3 to 6 months of symptoms was predictive for achieving the minimal clinically important difference on the HOS-ADL (odds ratio [OR], 1.81; 95% CI, 1.20-2.73) and HOS-SS (OR, 1.90; 95% CI, 1.11-3.17), as well as the patient acceptable symptomatic state on the HOS-ADL (OR, 1.85; 95% CI, 1.34-2.56) and HOS-SS (OR, 1.58; 95% CI, 1.14-2.18), when compared with the other groups. In multivariate regression analysis, symptom duration was predictive of visual analog scale for pain (β = 3.10; 95% CI, 1.56-4.63; P < .001) and satisfaction (β = −4.16; 95% CI, −6.14 to −2.18; P < .001).Conclusion:Among patients with FAIS, surgical intervention early after the onset of symptoms (3-6 months) was associated with superior postoperative outcomes when compared with patients who underwent surgical intervention beyond this time frame. This information may help guide preoperative decision making regarding delay of surgery. These findings should be confirmed in a prospective study.
Minimum 5-Year Outcomes of Arthroscopic Hip Labral Reconstruction With Nested Matched-Pair Benchmarking Against a Labral Repair Control Group
The American Journal of Sports Medicine, .
Background:Labral reconstruction has demonstrated short-term benefit for the treatment of irreparable labral tears. Nonetheless, there is a scarcity of evidence for midterm outcomes of this treatment.Hypotheses:Arthroscopic segmental reconstruction in the setting of irreparable labral tears would show improvement in patient-reported outcomes (PROs) and high patient satisfaction at minimum 5-year follow-up. Second, primary labral reconstruction (PLRECON) would result in similar improvement in PROs at minimum 5-year follow-up when compared with a matched-pair primary labral repair (PLREPAIR) control group.Study Design:Cohort study; Level of evidence, 3.Methods:Data from February 2008 to April 2013 were retrospectively reviewed. Patients were included if they underwent hip arthroscopy for segmental labral reconstruction in the setting of irreparable labral tear and femoroacetabular impingement, with minimum 5-year follow-up for modified Harris Hip Score, Nonarthritic Hip Score, Hip Outcome Score–Sports Specific Subscale, patient satisfaction, and visual analog scale for pain. Exclusion criteria were Tönnis osteoarthritis grade >1, prior hip conditions, or workers’ compensation claims. PLRECON cases were matched in a 1:3 ratio to a PLREPAIR control group based on age ±5 years, sex, and body mass index ±5 kg/m2.Results:Twenty-eight patients were eligible for the study, of which 23 (82.14%) had minimum 5-year follow-up. The authors found significant improvement from preoperative to latest follow-up in all outcome measures recorded: 17.8-point increase in modified Harris Hip Score (P = .002), 22-point increase in Nonarthritic Hip Score (P < .001), 25.4-point increase in Hip Outcome Score–Sports Specific Subscale (P = .003), and a 2.9-point decrease in visual analog scale pain ratings (P < .001). Mean patient satisfaction was 7.1 out of 10. In the nested matched-pair analysis, 17 patients who underwent PLRECON were matched to a control group of 51 patients who underwent PLREPAIR. PLRECON demonstrated comparable survivorship and comparable improvements in all PROs with the exception of patient satisfaction (6.7 vs 8.5, P = .04).Conclusion:Hip arthroscopy with segmental labral reconstruction resulted in significant improvement in PROs at minimum 5-year follow-up. PLRECON reached comparable functional outcomes when compared with a benchmark PLREPAIR control group but demonstrated lower patient satisfaction at latest follow-up.
An Anterior Cruciate Ligament Failure Mechanism
The American Journal of Sports Medicine, .
Background:Nearly three-quarters of anterior cruciate ligament (ACL) injuries occur as “noncontact” failures from routine athletic maneuvers. Recent in vitro studies revealed that repetitive strenuous submaximal knee loading known to especially strain the ACL can lead to its fatigue failure, often at the ACL femoral enthesis.Hypothesis:ACL failure can be caused by accumulated tissue fatigue damage: specifically, chemical and structural evidence of this fatigue process will be found at the femoral enthesis of ACLs from tested cadaveric knees, as well as in ACL explants removed from patients undergoing ACL reconstruction.Study Design:Controlled laboratory study.Methods:One knee from each of 7 pairs of adult cadaveric knees were repetitively loaded under 4 times–body weight simulated pivot landings known to strain the ACL submaximally while the contralateral, unloaded knee was used as a comparison. The chemical and structural changes associated with this repetitive loading were characterized at the ACL femoral enthesis at multiple hierarchical collagen levels by employing atomic force microscopy (AFM), AFM–infrared spectroscopy, molecular targeting with a fluorescently labeled collagen hybridizing peptide, and second harmonic imaging microscopy. Explants from ACL femoral entheses from the injured knee of 5 patients with noncontact ACL failure were also characterized via similar methods.Results:AFM–infrared spectroscopy and collagen hybridizing peptide binding indicate that the characteristic molecular damage was an unraveling of the collagen molecular triple helix. AFM detected disruption of collagen fibrils in the forms of reduced topographical surface thickness and the induction of ~30- to 100-nm voids in the collagen fibril matrix for mechanically tested samples. Second harmonic imaging microscopy detected the induction of ~10- to 100-µm regions where the noncentrosymmetric structure of collagen had been disrupted. These mechanically induced changes, ranging from molecular to microscale disruption of normal collagen structure, represent a previously unreported aspect of tissue fatigue damage in noncontact ACL failure. Confirmatory evidence came from the explants of 5 patients undergoing ACL reconstruction, which exhibited the same pattern of molecular, nanoscale, and microscale structural damage detected in the mechanically tested cadaveric samples.Conclusion:The authors found evidence of accumulated damage to collagen fibrils and fibers at the ACL femoral enthesis at the time of surgery for noncontact ACL failure. This tissue damage was similar to that found in donor knees subjected in vitro to repetitive 4 times–body weight impulsive 3-dimensional loading known to cause a fatigue failure of the ACL.Clinical Relevance:These findings suggest that some ACL injuries may be due to an exacerbation of preexisting hierarchical tissue damage from activities known to place larger-than-normal loads on the ACL. Too rapid an increase in these activities could cause ACL tissue damage to accumulate across length scales, thereby affecting ACL structural integrity before it has time to repair. Prevention necessitates an understanding of how ACL loading magnitude and frequency are anabolic, neutral, or catabolic to the ligament.
Anterior and Rotational Knee Laxity Does Not Affect Patient-Reported Knee Function 2 Years After Anterior Cruciate Ligament Reconstruction
The American Journal of Sports Medicine, .
Background:While a primary goal of anterior cruciate ligament (ACL) reconstruction is to reduce pathologically increased anterior and rotational knee laxity, the relationship between knee laxity after ACL reconstruction and patient-reported knee function remains unclear.Hypothesis:There would be no significant correlation between the degree of residual anterior and rotational knee laxity and patient-reported outcomes (PROs) 2 years after primary ACL reconstruction.Study Design:Cross-sectional study; Level of evidence, 3.Methods:From a prospective multicenter nested cohort of patients, 433 patients younger than 36 years of age injured in sports with no history of concomitant ligament surgery, revision ACL surgery, or surgery of the contralateral knee were identified and evaluated at a minimum 2 years after primary ACL reconstruction. Each patient underwent Lachman and pivot-shift evaluation as well as a KT-1000 arthrometer assessment along with Knee injury and Osteoarthritis Outcome Score and subjective International Knee Documentation Committee (IKDC) scores. A proportional odds logistic regression model was used to predict each 2-year PRO score, controlling for preoperative score, age, sex, body mass index, smoking, Marx activity score, education, subsequent surgery, meniscal and cartilage status, graft type, and range of motion asymmetry. Measures of knee laxity were independently added to each model to determine correlation with PROs.Results:Side-to-side manual Lachman differences were IKDC A in 246 (57%) patients, IKDC B in 183 (42%) patients, and IKDC C in 4 (<1%) patients. Pivot-shift was classified as IKDC A in 209 (48%) patients, IKDC B in 183 (42%) patients, and IKDC C in 11 (2.5%) patients. The mean side-to-side KT-1000 difference was 2.0 ± 2.6 mm. No significant correlations were noted between pivot-shift or anterior tibial translation as assessed by Lachman or KT-1000 and any PRO. All predicted differences in PROs based on IKDC A versus B pivot-shift and anterior tibial translation were less than 4 points.Conclusion:Neither the presence of IKDC A versus B pivot-shift nor increased anterior tibial translation of up to 6 mm is associated with clinically relevant decreases in PROs 2 years after ACL reconstruction.
Decreased Graft Thickness Is Associated With Subchondral Cyst Formation After Osteochondral Allograft Transplantation in the Knee
The American Journal of Sports Medicine, .
Background:Subchondral changes, specifically cyst formation, are a known finding after osteochondral allograft (OCA) transplantation.Purpose/Hypothesis:The purpose was to determine potential predictive associations between preoperative patient characteristics or OCA morphology and postoperative OCA appearance as assessed by the osteochondral allograft magnetic resonance imaging scoring system (OCAMRISS) at 6-month follow-up. It was hypothesized that preoperative patient factors or OCA morphology is associated with postoperative OCAMRISS scores.Study Design:Cross-sectional study; Level of evidence, 3.Methods:This study evaluated 74 OCAs that were implanted in the femoral condyles of 63 patients for the treatment of symptomatic osteochondral defects in the knee. Postoperative magnetic resonance imaging was obtained at a mean ± SD follow-up of 5.5 ± 1.0 months. A musculoskeletal radiologist scored all grafts according to the OCAMRISS. Point biserial correlation, Mann-Whitney U test, Fisher exact test, and chi-square test were used to distinguish associations between OCAMRISS subscales and age, sex, smoker status, body mass index, previous surgery, concomitant surgery, bone marrow augmentation, graft location, graft size, and bony graft thickness.Results:OCA bony thickness showed significant correlation with cystic changes at the graft-host junction (P = .019). Grafts with cystic formation were significantly thinner than grafts without cystic changes (P = .008). The odds ratio for grafts with <5-mm bony thickness demonstrating cystic changes was 4.9 (95% CI, 1.5-16.1; P = .009). Bony graft thickness was not associated with graft integration, but 40% of grafts with a bony thickness >9 mm presented with a residual osseous cleft, as opposed to 11.3% of thinner grafts (P = .1). The augmentation with bone marrow aspirate did not affect osseous graft integration or subchondral cystic formation (P = .375 and P = .458, respectively).Conclusion:Osteochondral allograft thickness is associated with subchondral cyst formation at short-term follow-up. Thin grafts demonstrate a substantially increased risk of developing subchondral cysts at the graft-host junction after OCA transplantation. Conversely, thicker grafts may negatively affect osseous graft integration. Hence, surgeons should be aware of the potential pitfalls of transplanting thin or thick grafts regarding cystic formation and delay of osseous integration after cartilage resurfacing.
Risk Factors for Opioid Use After Anterior Cruciate Ligament Reconstruction
The American Journal of Sports Medicine, .
Background:The misuse of opioid medications has contributed to a significant national crisis affecting public health as well as patient morbidity and medical costs. After orthopaedic surgical procedures, patients may require prescription (Rx) opioid medication, which can fuel the opioid epidemic. Opioid Rx usage after anterior cruciate ligament reconstruction (ACLR) is not well characterized.Purpose:To determine baseline utilization of Rx opioids in patients undergoing ACLR and examine demographic, patient, and surgical factors associated with greater and prolonged postoperative opioid utilization.Study Design:Cohort study; Level of evidence, 3.Methods:Primary elective ACLRs were identified using Kaiser Permanente’s ACLR registry (2005-2015). We studied the association of perioperative risk factors on the number of dispensed opioid Rx in the early (0-90 days) and late (91-360 days) postoperative recovery periods using logistic regression.Results:Of 21,202 ACLRs, 25.5% used at least 1 opioid Rx in the 1-year preoperative period; 17.7% and 2.7% used ≥2 opioid Rx in the early and late recovery periods, respectively. Risk factors associated with greater opioid Rx in both the early and the late periods included the following: ≥2 preoperative opioid Rx, age ≥20 years, American Society of Anesthesiologists classification ≥3, other activity at the time of injury, chondroplasty, chronic pulmonary disease, and substance abuse. Risk factors associated with opioid Rx use during the early period only included the following: other race, acute injury, meniscal injury repair, multiligament injury, and dementia/psychosis. Risk factors associated with greater opioid Rx during the late period only included the following: 1 preoperative opioid Rx, female sex, body mass index ≥25 kg/m2, motor vehicle accident as the mechanism of injury, and hypertension.Conclusion:A quarter of ACLR patients had at least 1 opioid Rx before the procedure, but usage dropped to 2.7% toward the end of the postoperative year. We identified several perioperative risk factors for greater and prolonged opioid usage after ACLR.
Analysis of Return to Sport and Weight Training After Repair of the Pectoralis Major Tendon
The American Journal of Sports Medicine, .
Background:The use of routine patient-reported outcomes after repair of the pectoralis major tendon (PMT) is often prone to the ceiling effect owing to the high functional demand of those who sustain this injury.Hypothesis:A significant number of patients are expected to fail to achieve return to preoperative activity after PMT repair despite achieving significant improvements in functional score.Study Design:Case series; Level of evidence, 4.Methods:A prospectively maintained institutional database was reviewed for all patients undergoing PMT repair from 2010 to 2016. Patients were surveyed with regard to pre- and postoperative participation in sports, level of intensity, maximum weight repetitions in exercises utilizing the PMT, and American Shoulder and Elbow Surgeons (ASES) and Single Assessment Numeric Evaluation (SANE) scores.Results:Forty-four patients (73.3%) were available for final follow-up. All patients were male. Mean ± SD follow-up was 51.1 ± 24.1 months. Mean age was 39.6 ± 8.8 years (range, 24-61 years), and mean body mass index was 28.6 ± 3.5 kg/m2. The dominant side was affected in 20 of 44 cases. Acute repairs were performed in 30 cases and chronic in 14. There were statistically significant improvements in both ASES and SANE scores (P < .001). Return to sport at any level was achieved by 43 of 44 (97.7%) patients, while 22 of 44 patients (50.0%) reported returning to sport at the same or better intensity as preinjury status. On average, there was a 23.3% ± 45.6% decrease in 1–repetition maximum (1RM) barbell bench press, 14.7% ± 62.3% decrease in 5–repetition maximum barbell bench press, 24.3% ± 21.8% decrease in 1RM dumbbell bench press, 35.7% ± 32.1% decrease in 1RM dumbbell fly, and 15.6% ± 39.8% decrease in consecutive push-ups able to be performed. Seventeen patients (38.6%) reported a degree of apprehension that affected their ability to lift weights. When all preoperative variables were accounted for, history of surgery to the contralateral shoulder (odds ratio, 0.600; 95% CI, 0.389-0.925) was associated with a decreased likelihood of returning to sport at the same or better level of intensity, while injury sustained during sport had a greater likelihood (odds ratio, 2.231; 95% CI, 1.234-4.031).Conclusion:Patients undergoing PMT repair should expect significant functional improvements and a low complication rate. Yet, only 50% are able to return to preoperative intensity of sport, and they will also have significant reductions in their ability to weight lift.
Dynamic Compressive Loading Improves Cartilage Repair in an In Vitro Model of Microfracture: Comparison of 2 Mechanical Loading Regimens on Simulated Microfracture Based on Fibrin Gel Scaffolds Encapsulating Connective Tissue Progenitor Cells
The American Journal of Sports Medicine, .
Background:Microfracture of focal chondral defects often produces fibrocartilage, which inconsistently integrates with the surrounding native tissue and possesses inferior mechanical properties compared with hyaline cartilage. Mechanical loading modulates cartilage during development, but it remains unclear how loads produced in the course of postoperative rehabilitation affect the formation of the new fibrocartilaginous tissue.Purpose:To assess the influence of different mechanical loading regimens, including dynamic compressive stress or rotational shear stress, on an in vitro model of microfracture repair based on fibrin gel scaffolds encapsulating connective tissue progenitor cells.Study Design:Controlled laboratory study.Methods:Cylindrical cores were made in bovine hyaline cartilage explants and filled with either (1) cartilage plug returned to original location (positive control), (2) fibrin gel (negative control), or (3) fibrin gel with encapsulated connective tissue progenitor cells (microfracture mimic). Constructs were then subjected to 1 of 3 loading regimens: (1) no loading (ie, unloaded), (2) dynamic compressive loading, or (3) rotational shear loading. On days 0, 7, 14, and 21, the integration strength between the outer chondral ring and the central insert was measured with an electroforce mechanical tester. The central core component, mimicking microfracture neotissue, was also analyzed for gene expression by real-time reverse-transcription polymerase chain reaction, glycosaminoglycan, and double-stranded DNA contents, and tissue morphology was analyzed histologically.Results:Integration strengths between the outer chondral ring and central neotissue of the cartilage plug and fibrin + cells groups significantly increased upon exposure to compressive loading compared with day 0 controls (P = .007). Compressive loading upregulated expression of chondrogenesis-associated genes (SRY-related HGMG box-containing gene 9 [SOX9], collagen type II α1 [COL2A1], and increased ratio of COL2A1 to collagen type I α1 [COL1A1], an indicator of more hyaline phenotype) in the neotissue of the fibrin + cells group compared with the unloaded group at day 21 (SOX9, P = .0032; COL2A1, P < .0001; COL2A1:COL1A1, P = .0308). Fibrin + cells constructs exposed to shear loading expressed higher levels of chondrogenic genes compared with the unloaded condition, but the levels were not as high as those for the compressive loading condition. Furthermore, catabolic markers (MMP3 and ADAMTS 5) were significantly upregulated by shear loading (P = .0234 and P < .0001, respectively) at day 21 compared with day 0.Conclusion:Dynamic compressive loading enhanced neotissue chondrogenesis and maturation in a simulated in vitro model of microfracture, with generation of more hyaline-like cartilage and improved integration with the surrounding tissue.Clinical Relevance:Controlled loading after microfracture may be beneficial in promoting the formation of more hyaline-like cartilage repair tissue; however, the loading regimens applied in this in vitro model do not yet fully reproduce the complex loading patterns created during clinical rehabilitation. Further optimization of in vitro models of cartilage repair may ultimately inform rehabilitation protocols.
Biomechanical Evaluation of the Medial Stabilizers of the Patella: Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 8, Page NP41-NP41, July 2019.
Biomechanical Evaluation of the Medial Stabilizers of the Patella: Response
The American Journal of Sports Medicine, Volume 47, Issue 8, Page NP41-NP42, July 2019.
The Glenoid Concavity Shape Is Insufficient to Challenge the Concept of Critical Cutoff Value of Glenoid Bone Loss in Clinical Practice: Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 8, Page NP43-NP43, July 2019.
The Glenoid Concavity Shape Is Insufficient to Challenge the Concept of Critical Cutoff Value of Glenoid Bone Loss in Clinical Practice: Response
The American Journal of Sports Medicine, Volume 47, Issue 8, Page NP44-NP44, July 2019.
Influence of Baseline Magnetic Resonance Imaging Features on Outcome of Arthroscopic Meniscectomy and Physical Therapy Treatment of Meniscal Tears in Osteoarthritis: Letter to the Editor
The American Journal of Sports Medicine, Volume 47, Issue 8, Page NP45-NP46, July 2019.
Influence of Baseline Magnetic Resonance Imaging Features on Outcome of Arthroscopic Meniscectomy and Physical Therapy Treatment of Meniscal Tears in Osteoarthritis: Response
The American Journal of Sports Medicine, Volume 47, Issue 8, Page NP46-NP47, July 2019.
Hybrid Vigor (?)
The American Journal of Sports Medicine, .
Severe Bone Marrow Edema Among Patients Who Underwent Prior Marrow Stimulation Technique Is a Significant Predictor of Graft Failure After Autologous Chondrocyte Implantation
The American Journal of Sports Medicine, .
Background:Autologous chondrocyte implantation (ACI) is a well-established cartilage repair procedure; however, numerous studies have shown higher ACI graft failure rates after prior marrow stimulation techniques (MSTs).Purpose:To identify which factors may predict decreased graft survival after ACI among patients who underwent a prior MST. A secondary aim was to investigate the specificity of these predictors.Study Design:Case-control study; Level of evidence, 3.Methods:In this review of prospectively collected data, the authors analyzed 38 patients who had failed prior MST surgery and subsequently underwent collagen-covered ACI (case group). The case group was divided into graft failure ACI (n = 8, 21%) and successful ACI (n = 30, 79%). Fourteen clinical variables were categorized and analyzed to determine predictors for failure of the ACI graft: age, body mass index, sex, defect characteristics (number, size, location, etiology, type), presence of kissing lesion, intraoperative presence of intralesional osteophyte, time between an MST and ACI, previous surgery, duration of the symptoms, and concomitant surgical procedure. Preoperative magnetic resonance imaging (MRI) was used to evaluate the severity of subchondral bone marrow edema (BME), graded I (absent) to IV (severe), and the presence of subchondral cyst, hypertrophic sclerosis, and intralesional osteophyte. The effects of these MRI findings on the graft survivor were also investigated. Concurrently, a control group without a prior MST was matched to investigate the specificity of the previously determined predictors. These patients were matched individually according to age, sex, body mass index, and outcome of the procedure (failure [n = 8] or successful [n = 30] per the case group).Results:In the case group, the presence of preoperative severe BME was significantly higher among patients with failed ACI as compared with patients with successful ACI (P < .001). In the control group, the presence of severe BME was not significantly different between the failure and successful groups (P = .747). The ACI graft failure rate among patients with a prior MST and preoperative grade IV BME was 83.7% at 5 years postoperatively, resulting in a significantly lower survival rate as compared with patients with a prior MST and without severe BME (5-year graft failure rate, 6.5%; P < .001). All the other parameters did not differ significantly.Conclusion:After a prior MST, the presence of grade IV BME by MRI was a predictive factor for graft failure among patients who then underwent second-generation ACI.
Society News
The American Journal of Sports Medicine, .
Corrigendum
The American Journal of Sports Medicine, Volume 47, Issue 7, Page NP39-NP39, June 2019.
Corrigendum
The American Journal of Sports Medicine, Volume 47, Issue 7, Page NP40-NP40, June 2019.
The Shoulder Tap
The American Journal of Sports Medicine, .
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    • Ab dem 25. Mai 2018 können Sie in Ihrem Kundenkonto unter „meine Einstellungen“ den gewünschten Datenschutz selbst einstellen.

    Bei Fragen wenden Sie sich bitte jederzeit an unseren vub-Kundenservice und Ihre bekannten Ansprechpartner unter premiumservice@vub.de.

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