Comparison of isometric strength in rotator cuff and scapulothoracic muscles between elite volleyball athletes versus non-athletes.

BACKGROUND: Volleyball is an exceptionally popular global sport that involves repetitive, rapid, powerful and wide overhead movements, which can seriously alter normal shoulder kinematics. A recognized hallmark of shoulder muscle balance is the ratio of shoulder external (ER) and internal (IR) rotators. By extension, objective measurement of shoulder muscles' strength could help identify at risk athletes and preempt those injuries by engaging in prescriptive strength training programs. METHODS: This cross-sectional study measured the isometric strengths of 1) shoulder internal and external rotator muscles, as well as the 2) supraspinatus, 3) rhomboid, and 4) middle and inferior trapezius muscles, in addition to calculation of ER:IR ratios, in professional volleyball players as well as in non-athletes. Measurements were made for dominant- and non-dominant upper limbs, in different position of the body (supine and orthostatic) and in different position of upper limb (adducted and abducted position). Our subject population included 11 male professional volleyball players as well as 14 healthy male orthopedic interns from Orthopedics and Trauma school of University of Milano Bicocca. Strengths were assessed by a handheld dynamometer. Each subject's isometric strength was assessed in triplicate in each limb position through a "make test" procedure; the greatest of each triplicate value was the accepted measure of isometric strength. RESULTS: We observed a gradient in muscle strength in the scapulothoracic complex in both groups; the rhomboid, middle trapezius, and lower trapezius ranked from greatest to least strength, respectively. The data suggest also that intrarotators are stronger in rotation adducted position than in rotation abducted position; however, extrarotators seem to be weaker in rotation adducted position than in rotation abducted position. There is also some indication that force development is enhanced in the supine position compared with the orthostatic position. CONCLUSIONS: Our findings indicate a scapulothoracic strength gradient with a rank order of strength of the rhomboid>middle trapezius>lower trapezius. The data further suggest that volleyball players have stronger intrarotation in rotation adducted position than in the rotation abducted position, while extra rotation shows the opposite trend. Finally, our data suggest that force development is greater in the supine position compared to the orthostatic position.

Prokineticin 2 and Cytokine Content in the Synovial Fluid of Knee Osteoarthritis and Traumatic Meniscal Tear Patients: Preliminary Results.

Knee osteoarthritis (OA) is a chronic degenerative inflammatory-based condition caused by a cascade of different intra-articular molecules including several cytokines. Among the cytokines, prokineticins (PKs) have recently been identified as important mediators of inflammation and pain. This observational study examined the potential involvement of PK2 in degenerative or traumatic knee disease. Fifteen patients presenting knee osteoarthritis (OA group) and 15 patients presenting a traumatic meniscal tear (TM group) were studied. Synovial fluid samples from affected knees were assessed for PK2, IL-10, and TNF-α using the ELISA method. At a long-term follow-up (minimum 5 years, mean = 6.1 years), patients in the TM group underwent clinical re-evaluation with PROMs (Tegner Activity Scale, IKDC, Lysholm, SKV); in addition, X-ray visualization was used to assess the presence of secondary OA. PK2 was detected in synovial fluids of both TM and OA patients and the levels were comparable between the two groups, while IL-10 levels were significantly greater in the OA group than those in TM patients. PK2 levels correlated with those of IL-10. PK2 levels were greater in blood effusions compared to clear samples, did not differ significantly between sexes, nor were they related to differences in weight, height, or injury (meniscal laterality, time since dosing). No correlation was found between PROMs and radiological classifications in patients in the TM group at final follow-up. These data are the first observations of PK2 in synovial fluid following traumatic meniscus injury. These findings suggest possible further prognostic indices and therapeutic targets to limit the development of secondary OA.

Meniscal Allograft Transplants in Skeletally Immature Patients: A Systematic Review of Indications and Outcomes.

Meniscal lesions in skeletally immature patients can lead to joint degradation and knee instability. Meniscal allograft transplant (MAT) surgery is a solution to maintain knee stability. There is a lack of consensus on MAT surgery outcomes in pediatric patients. A systematic review was conducted according to the PRISMA guidelines. PubMed, Scopus and EMBASE databases were searched from 1965 to June 2022. Studies were evaluated using the Newcastle-Ottawa Scale (NOS). Three studies were selected, and 58 patients were included (mean age 15.9 years) in total. The lateral meniscus was involved in 82.8% of all MAT surgeries. Post-meniscectomy syndrome and discoid meniscus were the main indications for MAT surgery. All studies reported improved subjective clinical scores and levels of sport after the surgery. The complication rate was 27.5%. Partial meniscectomy, meniscus knot removal, chondral defect treatment and lysis of adhesions were the most frequent procedures performed during reoperation. MAT surgery can improve clinical outcomes in pediatric patients with strictly selected indications. MAT surgery is safe when there are no limb asymmetries or malalignments, but it remains a challenging procedure with a high complication rate. Long-term follow-up is needed for definitive statements on the use of MAT in skeletally immature patients.

Comparison of all-suture anchors with metallic anchors in arthroscopic cuff repair: Structural and functional properties and clinical suitability.

Purpose: This study examined and compared all-suture anchors with metallic anchors in the arthroscopic repair of small to medium supraspinatus tears; a multi-dimensional evaluation protocol assessed (i) clinical, (ii) ultrasonographical, and (iii) functional criteria at mid-term. Materials and methods: A sample of 40 patients, prescreened from a larger group who had undergone arthroscopic rotator cuff repair, were resolved into two groups of 20, based on the type of anchor used in their surgery (all-suture or metallic) and were evaluated postoperatively (mean = 44.3 months, SEM = 22.4 months, minimum period = 10.3 months). Clinical assessments included (i) objective and subjective scores (Constant, DASH, SPADI, SST), (ii) ultrasonographical examination, as well as (iii) isometric and isokinetic strength testing. Raw data from the operated side was compared with those from the contralateral side within each group. Raw data for the PROMs and for the US evaluation were compared between groups. Strength data, as well as the Constant score values, were further analyzed based on (i) the difference between operated and intact sides, as well as (ii) the strength ratio between operated and intact sides; the transformed data were then compared between the two groups. Results: We found no statistically significant differences in any of the parameters considered between shoulders operated using ASAs or MAs, nor between operated and non-operated sides in each group. Conclusion: Our findings indicate that the reliability and performance characteristics of all-suture anchors and metallic anchors are practically indistinguishable for arthroscopic treatment of small to medium lesions of the supraspinatus tendon.

Non-Union Scoring System (NUSS): Is It Enough in Clinical Practice?

Introduction: Bone consolidation defects represent a real orthopedic challenge because of the absence of validated treatment guidelines that can assist the surgeon in his choices. The aim of this study is to evaluate the appropriateness of the Non-Union Scoring System NUSS treatment protocol in the management of long bone non-unions by comparing it to the experience-based therapeutic approach carried out in our facility. Materials and Methods: We conducted a comparative outcome study of a retrospective series of 89 patients surgically treated for long bone non-union in our facility vs. clinical results reported by Calori et al. obtained following the NUSS treatment protocol. Results: Radiographic healing was reached in 13/13 non-unions (100%) in group NUSS 1, in 58/62 (93.5%) in group NUSS 2, and in 13/14 (92.9%) in group NUSS 3. The mean time to radiographic healing was 5.69 ± 2.09 months in group 1, 7.38 ± 3.81 months in group 2 and 9.23 ± 2.31 months in group 3. 91% of patients in group I, 69% in group II and 48% in group III received what would be considered by the NUSS treatment protocol an "overtreatment", especially from a biological stand point. The comparative outcome analysis shows that our case series achieved significantly higher global healing rates (p value = 0.017) and shorter radiological healing times in groups NUSS 1 and 2 (p value < 0.001). Conclusion: From the results obtained, we can assume that the NUSS treatment protocol might underestimate the necessary therapies, particularly from a biological point of view.

Clinical outcomes and complications after anterior cruciate ligament reconstruction with bone-patellar tendon-bone in patient Tanner 3 and 4: a systematic review.

BACKGROUND: Clinical outcomes and potential complications associated with Bone-Patellar Tendon-Bone (BPTB) graft in skeletally immature ACL reconstruction (ACLR) are poorly defined. Considering that in Tanner 1-2 patients this kind of graft is not recommended, we focused our systematic review on the evaluation of all the studies in the literature that reported clinical outcomes and rate of complications of the ACLR using BPTB graft in Tanner 3-4 patients. METHODS: This review was conducted in accordance with the PRISMA statement. PubMed, Cochrane Library, EMBASE and Scopus were examined from 1965 to 2020 using different combinations of the following keywords: "ACL reconstruction", "skeletally immature", "young", "patellar tendon" and "BPTB". The database search yielded 742 studies, on which we performed a primary evaluation. After carrying out a full-text evaluation for the inclusion criteria, 4 studies were included in the final review and assessed using the Newcastle-Ottawa scale. Ninety-six cases with mean age of 14.2 years were reported. RESULTS: Good stability and functional outcomes were reported with a mean follow-up of 49.5 months. Return to sport rate ranged from 91.7% to 100%. A KT-1000 side-to-side difference higher than 5 mm was observed in five patients (5.2%). No lower limb length discrepancy and angulation were reported. Graft rupture rate was 5.2%. CONCLUSION: According to these results, BTPB graft could be a good choice in Tanner 3-4 patients who want to achieve their preinjury sport level with a low risk of growth disturbances and graft failure. Further investigations in a wider population are needed.

Management of anterior cruciate ligament tears in Tanner stage 1 and 2 children: a narrative review and treatment algorithm guided by ACL tear location.

The incidence of anterior cruciate ligament (ACL) tears in skeletally immature patients has acutely increased over the last 20 years, yet there is no consensus on a single "best treatment." Selection of an optimal treatment is critical and based on individual circumstances; consequently, we propose a treatment-selection algorithm based on skeletal development, ACL tear location, type, and quality, as well as parental perspective in order to facilitate the decision-making process. We combined our surgical group's extensive case histories of ACL tear management in Tanner Stage 1 and 2 patients with those in the literature to form a consolidated data base. For each case the diagnostic phase, communication with patient and parents, treatment choice(s), selected surgical techniques and rehabilitation schedule were critically analyzed and compared for patient outcomes. MRI-imaging and intraoperative tissue quality assessment were preeminent in importance for selection of the optimal treatment strategy. Considerations for selecting an optimal treatment included: associated lesions, the child/patient and parent(s)' well-informed and counseled consent, biological potential, and the potential for successful ACL preservative surgery. Complete ACL tears were evaluated according to tear-location. In type I and II ACL tears with remaining good tissue quality, we propose primary ACL repair. In type III and IV ACL tears we propose physeal-sparing reconstruction with an iliotibial band graft. Finally, in the case of a type V ACL tear, we propose that the best treatment be based on the Meyers-McKeever classification. We present a facile decision-making algorithm for ACL management in pediatric patients based on specific elements of tissue damage and status.

Characterization of microRNA Levels in Synovial Fluid from Knee Osteoarthritis and Anterior Cruciate Ligament Tears.

This study investigated modifications of microRNA expression profiles in knee synovial fluid of patients with osteoarthritis (OA) and rupture of the anterior cruciate ligament (ACL). Twelve microRNAs (26a-5p, 27a-3p, let7a-5p, 140-5p, 146-5p, 155-5p, 16-5p,186-5p, 199a-3p, 210-3p, 205-5p, and 30b-5p) were measured by real-time quantitative polymerase chain reaction (RT-qPCR) in synovial fluids obtained from 30 patients with ACL tear and 18 patients with knee OA. These 12 miRNAs were chosen on the basis of their involvement in pathological processes of bone and cartilage. Our results show that miR-26a-5p, miR-186-5p, and miR-30b-5p were expressed in the majority of OA and ACL tear samples, whereas miR-199a-3p, miR-210-3p, and miR-205-5p were detectable only in a few samples. Interestingly, miR-140-5p was expressed in only one sample of thirty in the ACL tear group. miR-140-5p has been proposed to modulate two genes (BGN and COL5A1100) that are involved in ligamentous homeostasis; their altered expression could be linked with ACL rupture susceptibility. The expression of miR-30b-5p was higher in OA and chronic ACL groups compared to acute ACL samples. We provide evidence that specific miRNAs could be detected not only in synovial fluid of patients with OA, but also in post-traumatic ACL tears.

Acute Ankle Sprain Management: An Umbrella Review of Systematic Reviews.

Even though ankle sprains are among the most frequent musculoskeletal injuries seen in emergency departments, management of these injuries continues to lack standardization. Our objective was to carry out an umbrella review of systematic reviews to collect the most effective evidence-based treatments and to point out the state-of-the-art management for this injury. PubMed, Scopus, Web of Science, and the Cochrane library were searched from January 2000 to September 2020. After removing duplicates and applying the eligibility criteria, based on titles and abstracts, 32 studies were screened. At the end of the process, 24 articles were included in this umbrella review with a mean score of 7.7/11 on the AMSTAR quality assessment tool. We found evidence supporting the effectiveness of non-surgical treatment in managing acute ankle sprain; moreover, functional treatment seems to be preferable to immobilization. We also found evidence supporting the use of paracetamol or opioids as effective alternatives to non-steroidal anti-inflammatory drugs to reduce pain. Furthermore, we found evidence supporting the effectiveness of manipulative and supervised exercise therapy to prevent re-injury and restore ankle dorsiflexion.

Comparison of two arthroscopic repair techniques for small-medium supraspinatus tendon tear: 1 triple-loaded vs 2 double-loaded metallic sutures anchors.

Introduction: Surgical repair of the rotator cuff is based on the use of anchors whose ideal numbers and configurations continue to be controversial. We compared the clinical-functional results arising from the arthroscopic repair of shoulders, with small-medium lesions of the supraspinatus tendon, among patients using one anchor with three sutures, or two anchors with two sutures. Methods: In this retrospective study patient were resolved into 2 groups. Clinical and functional results were assessed based on Constant Score and instrumental isometric examination. Results: Patients in Group 1 experienced shoulder repair using a single anchor with three sutures (n = 21, mean age = 56 years, range = 51-65). In Group 2, patients received two anchors with two sutures each (n = 24, mean age = 59 years, range = 24-75). The mean follow-up time was 15 months. The mean values of the operated shoulders' Constant Score were 88.05 and 88.25 respectively. Examination of isometric test results in operated shoulders, healthy shoulders and the two different rotator cuff repair techniques did not reveal any statistically significant differences. Conclusion: In the arthroscopic repair of small-medium supraspinatus tendon tears, the short to mid-term clinical and functional outcomes arising from use of 1 triple-loaded or 2 double-loaded metallic sutures anchors are comparable.

Jump performance during a season in elite volleyball players.

BACKGROUND: The aim of this study was to measure and compare jump load and dynamic performance in elite volleyball athletes under varied conditions over an entire season of practices and games. Jump load and dynamic performance were compared among best jump height, mean jump height, as well as according to the number of jumps per game or practice session and the proportion of jumps higher than 50 cm relative to the total number of jumps in a practice or game. METHODS: Every jump performed by each of 12 players, in all practices and regular games (813 player-sessions in total), was measured by a particle accelerometer in accordance with a validated protocol (Vert, Fort Lauderdale, FL, USA). Data were collected and analyzed using STATA (SataCorp, College Station, TX, USA); the significance level for definition of confidence intervals was set to 95%, unless otherwise specified. Statistical analysis and comparison of means and proportions between groups was based on standard t-tests. RESULTS: Among player positions, the middle blocker consistently presented the greatest jump loads during the season; by comparison, the smallest jump loads were observed in the setter. CONCLUSIONS: Monitoring players' jump loads and performance using a simple accelerometer provides evidence which can be used to plan individual player activity, roster composition, the season calendar and furthermore increase knowledge to reduce over-training and recurrence of injuries.

Resolvin E1 and Cytokines Environment in Skeletally Immature and Adult ACL Tears.

The intra-articular synovial fluid environment in skeletally immature patients following an ACL tear is complex and remains undefined. Levels of inflammatory and anti-inflammatory cytokines change significantly in response to trauma and collectively define the inflammatory environment. Of these factors the resolvins, with their inherent anti-inflammatory, reparative, and analgesic properties, have become prominent. This study examined the levels of resolvins and other cytokines after ACL tears in skeletally immature and adult patients in order to determine if skeletal maturity affects the inflammatory pattern. Skeletally immature and adult patients with an anterior cruciate ligament injury and meniscal tears were prospectively enrolled over a 5-month period. Synovial fluid samples were obtained before surgery quantifying Resolvin E1, IL-1ß, TNF-α, and IL-10 by ELISA. Comparisons between skeletally immature patients and adults, the influence of meniscal tear, growth plate maturity and time from trauma were analyzed. Skeletally immature patients had significantly greater levels of Resolvin E1 and IL-10 compared with adults with an isolated anterior cruciate ligament lesion. Among the injured skeletally immature patients Resolvin E1 levels were greater in the open growth plate group compared with those with closing growth plates. Moreover, levels of Resolvin E1 and IL-10 appeared to decrease with time. Our results suggest that skeletally immature patients have a stronger activation of the Resolvin pattern compared to adult patients and that synovial fluid Resolvins could play an antinflammatory role in the knee after anterior cruciate ligament lesion and that its activity may be synergistic with that of IL-10.

Discoid meniscus in human fetuses: A systematic review.

BACKGROUND: Discoid meniscus (DM) is a rare variant of regular knee anatomy. Compared to standard meniscus it is thicker and abnormal in shape; these characteristics make it more prone to tear. It is a congenital defect whose correct etiology is still debated and far from being clarified. The purpose of this systematic review is to evaluate evidences of DM in human fetuses in order to assess whether embryological development may have a role. METHODS: A systematic review was performed on PubMed, Scopus, and Embase with different combinations of the keywords "discoid meniscus", "embryology", "fetus", "neonatal". Search yielded 1013 studies, on which we performed a primary evaluation. RESULTS: Seven studies were considered including a total of 1378 fetal menisci specimens, from 396 different fetuses. Discoid shape was not found represented as a normal stage of prenatal development. From 782 lateral menisci analyzed, only 86 (10.86%) were discoid (13 complete, 73 incomplete type). None of medial menisci was found to be discoid. Lateral meniscus was observed to cover a larger surface of tibial plateau than medial one until 28th gestational week. CONCLUSION: Lateral meniscus seems to be more prone to discoid shape for its natural tendency of covering a larger surface of the tibial plateau during fetal stages. However the fact that a discoid shape was not found in the majority of fetuses suggests that it is not a normal stage of fetal development. To support a single etiological factor it will be appropriate to have further morphological and morphometric studies.

An arthroscopic repair technique for proximal anterior cruciate tears in children to restore active function and avoid growth disturbances.

PURPOSE: The aim of this study was to assess midterm clinical outcomes in Tanner 1-2 patients with proximal anterior cruciate ligament (ACL) tears following arthroscopic-surgical repair using an absorbable or an all-suture anchor. METHODS: Fourteen (9.2 ± 2.9 years-old) of 19 skeletally immature patients reached the 2 years of clinical follow-up. Physical examinations included the Lachman test, Pivot-shift test, One-leg Hop test, Pedi-IKDC as well as Lysholm and Tegner activity scores; knee stability was measured with a KT-1000 arthrometer. Overall re-rupture rates were also evaluated in all operated patients. RESULTS: At 2 years post-surgery, the Lysholm score was 93.6 ± 4.3 points, and the Pedi-IKDC score was 95.7 ± 0.1. All patients returned to the same sport activity level as prior to ACL lesion within 8.5 ± 2.9 months, with one exception who reported a one-point reduction in their Tegner Activity score. No leg-length discrepancies or malalignments were observed. Four patients presented grade 1 Lachman scores, and of these, three presented grade 1 (glide) score at Pivot-shift; clinical stability tests were negative for all other patients. Anterior tibial shift showed a mean side-to-side difference of 2.2 mm (range 1-3 mm). The One-leg Hop test showed lower limb symmetry (99.9% ± 9.5) with the contralateral side. Overall, 4 out of 19 patients presented a re-rupture of the ACL with a median time between surgery and re-rupture of 3.9 years (range 1-7). CONCLUSION: This surgical technique efficiently repairs proximal ACL tears, leading to a restoration of knee stability and a quick return to an active lifestyle, avoiding growth plate disruption. LEVEL OF EVIDENCE: IV.

Clinical effectiveness of surgical treatment with polyester tapes and temporary K-wires on complete acromioclavicular dislocation.

INTRODUCTION: Ideal treatment of acute acromioclavicular joint (ACJ) dislocation remains unresolved. We evaluated ACJ reconstruction using polyester tapes and temporary Kirschner wire (KW) and presented clinical and radiological outcomes. MATERIALS AND METHODS: Patients were retrospectively evaluated and classified according to Rockwood classification, clinical and sportive characteristics. Constant Score (CS) and ACJ joint instability (ACJI) score were collected. Zanca's, Alexander, axillary, standard, and stress AP views were collected. Radiographic coracoclavicular distance (CCd) of healthy and injured shoulders was measured pre-operatively, at 3 months and at minimum 2-year follow-up. Heterotopic ossifications and clavicular osteolysis were evaluated. Influence of patients' characteristics and AC joint type on clinical and radiological outcomes were determined. RESULTS: Sixteen patients (13 type V and 3 type III ACJ dislocation) reached the end of follow-up (mean 2.4 years; range 22-72 months). Mean CS was 99.63 (range 96-100), while the mean ACJI score was 96.19 (range 85-100). The CCd of the treated shoulder was comparable with the healthy shoulder at 3 months and at last follow-up; moreover, there was no difference in CCd scores at 3 months and at 2 years. CCd scores were lower in sedentary patients compared with physically active (sporty) patients. Heterotopic ossifications were observed in three patients. No osteolysis was reported. CONCLUSION: This technique provides good results with few complications and should be considered as an effective method to treat ACJ acute dislocation. CCd scores correlate with overuse factors but not with other clinical scores.

Intra-Articular Cytokine Levels in Adolescent Patients after Anterior Cruciate Ligament Tear.

The treatment of anterior cruciate ligament (ACL) injuries in children and adolescents is challenging. Preclinical and clinical studies investigated ACL repairing techniques in skeletally immature subjects. However, intra-articular bioenvironment following ACL tear has not yet been defined in skeletally immature patients. The aim of this study was to measure cytokine concentrations in the synovial fluid in adolescent population. Synovial levels of IL-1ß, IL-1ra, IL-6, IL-8, IL-10, and TNF-α were measured in 17 adolescent patients (15 boys) with ACL tears who underwent ACL reconstruction including acute (5), subacute (7), and chronic (5) phases. Femoral growth plates were classified as "open" in three patients, "closing" in eight, and "closed" in six. Eleven patients presented an ACL tear associated with a meniscal tear. The mean Tegner and Lysholm scores (mean ± SD) of all patients were 8 ± 1 and 50.76 ± 26, respectively. IL-8, TNF-α, and IL-1ß levels were significantly greater in patients with "open" physes. IL-1ra and IL-1ß levels were significantly higher in patients with ACL tear associated with a meniscal tear. Poor Lysholm scores were associated with elevated IL-6 and IL-10 levels. IL-10 levels positively correlated with IL-6 and IL-8 levels, whereas TNF-α concentration negatively correlated with IL-6 levels. Skeletally immature patients with meniscal tears and open growth plates have a characteristic cytokine profile with particularly elevated levels of proinflammatory cytokines including IL-8, TNF-α, and IL-1ß. This picture suggests that the ACL tear could promote an intra-articular catabolic response in adolescent patients greater than that generally reported for adult subjects. The study lacks the comparison with synovial samples from healthy skeletally immature knees due to ethical reasons. Overall, these data contribute to a better knowledge of adolescent intra-articular bioenvironment following ACL injuries.

Characterization of synovial fluid cytokine profiles in chronic meniscal tear of the knee.

Concentrations of pro- and anti-inflammatory cytokines in synovial fluid samples collected from patients with chronic meniscal tears were investigated. An acute inflammatory response is generally reported 24-48 h after knee injury, but the largest body of data available in literature concerns anterior cruciate ligament injury and very little information is available about the balance of soluble factors in the synovial fluid of knees with chronic meniscal tears. Sixty-nine patients (46 males and 23 females) with meniscal tear that occurred more than 3 months earlier were enrolled. According to cartilage integrity assessment by arthroscopic examination, patients were assigned to one of the following groups: (i) no chondral damage (n = 18); (ii) chondral damage graded from I to II (n = 15); and (iii) chondral damage graded from III to IV (n = 37). In all groups, levels of IL-10 and inflammatory cytokines IL-6, TNF-α, and IL-8 where greater compared with those reported in the intact population; by contrast, levels of IL-1ra and IL-1ß were significantly lower. Interestingly, IL-6 levels were higher in female than male patients. Cytokine levels did not correlate with degree of chondral damage. IL-6 and IL-1ra levels positively correlated with IL-1ß, and negatively correlated with TNF-α. Interestingly, levels of IL-1ß and TNF-α were inversely correlated. Our data demonstrate increased levels of pro-inflammatory cytokines (IL-6, IL-8, and TNF-α) in the chronic phase of meniscal trauma. This pro-inflammatory state is maintained in the joint from the time of initial injury to several months later and could be a key factor in hampering cartilage regeneration. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:340-346, 2017.