Knee osteoarthritis risk is increased 4-6 fold after knee injury - a systematic review and meta-analysis

Post-traumatic and OA-related lesions in the knee at baseline and 2 years after traumatic meniscal injury: Secondary analysis of a randomized controlled trial

OBJECTIVE

To assess the presence of early degenerative changes on Magnetic Resonance Imaging (MRI) 24 months after a traumatic meniscal tear and to compare these changes in patients treated with arthroscopic partial meniscectomy or physical therapy plus optional delayed arthroscopic partial meniscectomy.

DESIGN

We included patients aged 18-45 years with a recent onset, traumatic, MRI verified, isolated meniscal tear without radiographic osteoarthritis. Patients were randomized to arthroscopic partial meniscectomy or standardized physical therapy with optional delayed arthroscopic partial meniscectomy. MRIs at baseline and 24 months were scored using the MRI Osteoarthritis Knee Score (MOAKS). We compared baseline MRIs to healthy controls aged 18-40 years. The outcome was the progression of bone marrow lesions (BMLs), cartilage defects and osteophytes after 24 months in patients.

RESULTS

We included 99 patients and 50 controls. At baseline, grade 2 and 3 BMLs were present in 26% of the patients (n = 26), compared to 2% of the controls (n = 1) (between group difference 24% (95% CI 15% to 34%)). In patients, 35% (n = 35) had one or more cartilage defects grade 1 or higher, compared to 2% of controls (n = 1) (between group difference 33% (95% CI 23% to 44%)). At 24 months MRI was available for 40 patients randomized to arthroscopic partial meniscectomy and 41 patients randomized to physical therapy. At 24 months 30% (n = 12) of the patients randomized to arthroscopic partial meniscectomy showed BML worsening, compared to 22% (n = 9) of the patients randomized to physical therapy (between group difference 8% (95% CI -11% to 27%)). Worsening of cartilage defects was present in 40% (n = 16) of the arthroscopic partial meniscectomy group, compared to 22% (n = 9) of the physical therapy group (between group difference 18% (95% CI -2% to 38%)). Of the patients who had no cartilage defect at baseline, 33% of the arthroscopic partial meniscectomy group had a new cartilage defect at follow-up compared to 14% of the physical therapy group. Osteophyte worsening was present in 18% (n = 7) of the arthroscopic partial meniscectomy group and 15% (n = 6) of the physical therapy group (between group difference 3% (95% CI -13% to 19%)).

CONCLUSIONS

Our results might suggest more worsening of BMLs and cartilage defects with arthroscopic partial meniscectomy compared to physical therapy with optional delayed arthroscopic partial meniscectomy at 24-month follow-up in young patients with isolated traumatic meniscal tears without radiographic OA.

Treatment of osteoarthritic knee with high tibial osteotomy and allogeneic human umbilical cord blood-derived mesenchymal stem cells combined with hyaluronate hydrogel composite

BACKGROUND

Delaying total knee arthroplasty is crucial for middle-aged patients with severe osteoarthritis. The long-term outcomes of high tibial osteotomy (HTO) remain uncertain. Recently, mesenchymal stem cells (MSCs) have shown promising potential in enhancing cartilage regeneration. Therefore, this study aimed to assess cartilage regeneration following the implantation of allogeneic human umbilical cord blood-derived mesenchymal stem cells (hUCB-MSCs) with HTO.

METHODS

In this case series, ten patients underwent hUCB-MSC implantation with HTO. The median age was 58.50 (range: 57.00-60.00) years, and the mean body mass index was 27.81 (range: 24.42-32.24) kg/m2. Clinical outcomes, including the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), visual analog scale (VAS), Physical Component Score (PCS) and Mental Component Score (MCS) from the 36-Item Short-Form Health Survey (SF-36), were evaluated 6 months, 1 year, and 2 years postoperatively. Cartilage status of the medial femoral condyle (MFC) was assessed during hardware removal surgery, at least 2 years after the initial procedure, and compared with preoperative MFC cartilage status regarding lesion size and International Cartilage Repair Society (ICRS) grade. Radiological assessments included the Kellgren-Lawrence (KL) grading system for medial compartment osteoarthritis and hip-knee-ankle (HKA) angle.

RESULTS

Significant improvements were observed in WOMAC scores (preoperative: 57.00 (range: 44.75-63.00), postoperative: 27.50 (range: 22.25-28.75)), VAS scores (preoperative: 66.25 (range: 48.00-74.25), postoperative: 26.25 (range: 14.50-31.13)), SF-36 PCS (preoperative: 27.97 (range: 26.64-31.25), postoperative: 55.31 (range: 51.64-62.50)), and SF-36 MCS (preoperative: 41.04 (range: 29.95-50.96), postoperative: 63.18 (range: 53.83-65.16)) 2 years postoperatively (p = 0.002, 0.002, 0.002, and 0.020, respectively). The MFC chondral lesion demonstrated significant improvement in both lesion size (preoperative: 7.00 cm² (range: 4.38-10.50 cm²), postoperative: 0.16 cm² (range: 0.00-1.75 cm²), p = 0.002) and ICRS grade (preoperative: 4 (range: 4-4), postoperative: 1 (range: 1-2.25), p = 0.002). Additionally, the KL grade significantly decreased from 3 (range: 3-3) preoperatively to 2 (range: 2-2) postoperatively, while the HKA angle was corrected from 7.50° (range: 7.00-10.25°) preoperatively to -1.00° (range: -3.5-0.00°) postoperatively.

CONCLUSIONS

hUCB-MSC implantation with HTO is an effective treatment for medial compartment osteoarthritis and varus deformities, resulting in significant improvements in cartilage regeneration and overall clinical outcomes.

TRIAL REGISTRATION

NCT04234412.

Long-term Results of Bone-Patellar Tendon-Bone Versus Hamstring Tendon Autograft for Primary Anterior Cruciate Ligament Reconstruction: A Meta-analysis of Randomized Controlled Trials

Background

Bone-patellar tendon-bone (BTB) and hamstring tendon (HT) autografts are the most commonly utilized grafts for primary anterior cruciate ligament reconstruction (ACLR). While previous studies have compared outcomes using BTB and HT grafts for ACLR at short- and mid-term follow-ups, outcomes at long-term follow-ups remain unclear.

Purpose

To perform a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating BTB versus HT autografts for primary ACLR at a minimum 10-year follow-up.

Study Design

Systematic review; Level of evidence, 2.

Methods

A systematic review was performed in accordance with the 2020 PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by querying 5 databases from inception through May 2024 to identify level 1 and 2 RCTs evaluating outcomes of BTB versus HT autografts for primary ACLR at a minimum 10-year follow-up. A meta-analysis was performed using random-effects models with risk ratios (RRs) for discrete outcomes and mean differences (MDs) for continuous outcomes.

Results

Six RCTs-consisting of 495 (BTB, n = 235; HT, n = 260) patients-were identified. The mean age at the follow-up was 41.3 ± 7.4 years, with men comprising 64% (n = 316/495) of patients. The mean final follow-up time was 14.6 ± 0.7 years (range, 10-17 years). No significant differences were observed in ACL graft rupture or revision rates (RR, 0.88; P = .70), contralateral ACL rupture rates (RR, 1.27; P = .46), Lysholm scores (MD, -1.27; P = .45), Tegner scores (MD, -0.01; P = .97), extension deficits (RR, 2.67; P = .23), or KT-1000 side-to-side differences (MD, -0.56; P = .10). There was a significantly greater risk of osteoarthritis (OA) progression in ACLR knees compared with the contralateral knee (RR, 3.64; P < .0001); however, there was no difference in OA progression between BTB and HT groups (RR, 1.01; P = .91).

Conclusion

BTB and HT autografts for primary ACLR demonstrate similar outcomes and rates of OA progression at long-term follow-ups. Knees undergoing ACLR have a greater risk of OA progression compared with healthy contralateral knees.

Health Problems in Danish Adolescent Handball Players: Findings From the One-Season Health and Performance Promotion in Youth Sport (HAPPY) Study of 945 Players Aged 11-17 Years

We aimed to assess the in-season weekly average prevalence proportion, the incidence rate, and burden (the product of incidence rate and duration of injury in weeks) of health problems among Danish youth handball community players aged 11-17. In this 30-week prospective cohort study, players self-reported health problems, including all injuries and illnesses, regardless of time loss or medical attention, and handball exposure using weekly web-based surveys (OSTRC-H2). Sex differences were estimated using Poisson regression (incidence rates) and binomial regression (weekly average prevalence proportions) with clustered robust standard errors. We included 945 players (age: 14.5 ± 1.5 years; 55% female) from 20 clubs across Denmark. The response proportion to the weekly questionnaires was 63% (range: 42%-79%). The average prevalence proportion of health problems was 23% (95% CI 21%-25%), with 17% (95% CI 15%-19%) attributable to injuries and 6% (95% CI 5%-7%) to illnesses. The overall incidence rate was 14.9 (95% CI 13.9-15.9)/1000 h. Female players aged 13-15 showed a higher incidence rate (15.9 [95% CI 14.2-17.8]/1000 h) compared to age-matched males (13.2 [95% CI 11.5-15.1]/1000 h), with an incidence rate ratio of 1.21 [95% CI 1.0-1.4], and had a higher weekly average prevalence proportion (23% [95% CI 19%-27%]) than age-matched males (12% [95% CI 10%-15%]), corresponding to a difference of 10% points [95% CI 6%-15% points]. COVID-19 infection accounted for 36% of reported illnesses. Our findings highlight the need for injury prevention initiatives to address both sudden-onset and gradual-onset injuries in youth handball players. Sex differences in injury measures and the potential link between illness and injury risk warrant further investigation.

Symptoms indicative of early knee osteoarthritis after ACL reconstruction: descriptive analysis of the SHIELD cohort

Objective

To describe the SHIELD cohort in terms of symptoms indicative of early knee osteoarthritis (OA) and to investigate associations between patient characteristics (demographics, activity/injury-related) and these symptoms at 1 (cross-sectional) and 3 years (longitudinal) post anterior cruciate ligament reconstruction (ACLR).

Method

106 participants (50 ​% women, mean [SD] age 25 [5] years) were included. Symptoms indicative of early knee OA were evaluated by the Knee injury and Osteoarthritis Outcome Score (KOOS) subscale pain, KOOS subscale pain ≤72 (KOOSpain ≤72), and ≤85 on two out of four KOOS subscales (pain, symptoms, activity of daily living, quality of life) (modified Luyten).

Results

Mean (SD) KOOS pain scores were 83.2 (15.7) and 87.3 (12.7) at 1 and 3 years, respectively. At 1 year and 3 years post ACLR, 18/101 (18 ​%) and 14/86 (16 ​%) participants met the KOOSpain ≤72 criterion, whereas 83/101 (82 ​%) and 67/86 (78 ​%) met the modified Luyten criterion. 7/15 (47 ​%) (KOOSpain ≤72) and 59/70 (84 ​%) (modified Luyten) classified as having knee OA symptoms 1 year post ACLR were still classified as having OA symptoms after 3 years. Lower activity level at 1 year was the sole variable consistently associated with all three outcomes 3 years post ACLR.

Conclusion

The proportion of participants fulfilling existing classification criteria for symptoms indicative of early OA after ACLR is highly dependent on the criteria applied and different criteria seem to capture varying aspects of early OA symptoms. Future studies will reveal if these symptoms will persist long-term or just reflect more transient issues.

Machine learning-based prediction of contralateral knee osteoarthritis development using the Osteoarthritis Initiative and the Multicenter Osteoarthritis Study dataset

Having osteoarthritis in one knee is reported as an independent risk factor for developing contralateral knee osteoarthritis (KOA). However, no study has been designed to predict the development of contralateral KOA (cKOA). The authors hypothesized that specific risk factors for cKOA development exist and that it could be accurately predicted with the assistance of machine learning. KOA was defined using the Kellgren-Lawrence grade (KLG) of 2 or higher. Data from 1353 unilateral KOA patients (900 from the Osteoarthritis Initiative [OAI] and 453 from the Multicenter Osteoarthritis Study [MOST]) over 4-5 years of follow-up were examined. The risk factors for cKOA development were analyzed, and a machine learning model was developed to predict cKOA using OAI as the development data set and MOST as the test data set. cKOA developed in 172 (19.1%) and 178 (39.3%) of the patients (OAI and MOST, respectively) over a period of 4-5 years. A machine learning model was developed using the Tree-based Pipeline Optimization Tool algorithm. This model utilized nine variables, including baseline lateral joint space narrowing grade of the contralateral knee (odds ratio 4.475). The area under the curve of the receiver operating characteristics curve, along with accuracy, precision, and F1-score, were recorded as 0.69, 0.60, 0.50, and 0.58, respectively, in the test data set. The development of cKOA could be effectively predicted using a limited number of variables through machine learning. Surgeons should consider the development of cKOA in patients with identified risk factors when managing KOA patients.

Knee muscle strength and movement biomechanics in individuals with and without knee pain after anterior cruciate ligament reconstruction: A cross-sectional study

PURPOSE

Anterior cruciate ligament injury increases the risk of knee osteoarthritis, possibly via early onset of knee pain and changes in musculoskeletal function. This study compared knee muscle strength and movement biomechanics during walking and forward lunge between individuals with and without knee pain after anterior cruciate ligament reconstruction.

METHODS

Cross-sectional study including participants at least 3 years post anterior cruciate ligament reconstruction, aged 18-40 at the time of surgery, and body mass index ≤30. Symptomatic participants were defined by a knee pain score (reconstructed knee) of ≥3 on a 0-10 scale during activities of daily living in the past week. Asymptomatic participants were defined by a pain score of 0. Maximal isometric quadriceps and hamstring muscle strength (Nm/kg) and 3D walking, and forward lunge movement biomechanics were measured.

RESULTS

A total of 122 participants (30% females) were included: 33 symptomatic and 89 asymptomatic (average age: 33.7, range 23.7-51.3 years). The average post-surgery time was 6 (range 3-10) years. The symptomatic group exhibited lower isometric quadriceps and hamstring strength with mean group differences (95% confidence interval [CI]) of 0.33 (0.10 to 0.56) Nm/kg and 0.19 (0.07 to 0.31) Nm/kg, respectively. There were no important group differences in the walking and forward lunge movement biomechanics.

CONCLUSIONS

Symptomatic individuals with anterior cruciate ligament reconstruction demonstrated weaker knee muscles compared to their asymptomatic counterparts. The comparable walking and forward lunge biomechanics suggest that knee pain has no substantial impact on movement biomechanics up to 10 years post-surgery.

LEVEL OF EVIDENCE

Level III.

Knowledge, attitude and practice regarding anterior cruciate ligament injuries among the youth

OBJECTIVES

This study aimed to explore the knowledge, attitude, and practice (KAP) concerning anterior cruciate ligament (ACL) injuries among the youth.

METHODS

This cross-sectional study was conducted at Hospital of Chengdu University of TCM between January 2024 and March 2024, and included the youth aged from 18 to 39 years old. Demographic characteristics and KAP scores were collected via self-administered questionnaires.

RESULTS

A total of 561 valid questionnaires were analyzed. Of these, 292 respondents (52.05 %) were female, and 317 (56.51 %) had experienced ACL injuries or other related sports injuries. The mean scores for knowledge, attitudes, and practices were 19.99 ± 9.28 (possible range: 0-24), 30.34 ± 7.83 (possible range: 9-45), and 25.48 ± 7.40 (possible range: 7-35), respectively. Correlation analyses revealed significant positive correlations between knowledge and attitude (r = 0.506, P < 0.001), knowledge and practice (r = 0.612, P < 0.001), and attitude and practice (r = 0.546, P < 0.001). Structural equation modeling (SEM) indicated direct effects of knowledge on both attitude (β = 1.235, P < 0.001) and practice (β = 0.817, P < 0.001), as well as of attitude on practice (β = 0.490, P < 0.001).

CONCLUSION

The youth demonstrated adequate knowledge but moderate attitudes and practices regarding ACL injuries. Educational interventions targeting psychological factors, attitudes, and the translation of knowledge into consistent preventive behaviors are essential to mitigate injury risks and improve management outcomes among the youth.

Incidence and Risk Factors for Posttraumatic Osteoarthritis After Primary ACL Reconstruction in Pediatric Patients: A National Database Study

Background

The development of posttraumatic osteoarthritis (PTOA) of the knee after anterior cruciate ligament (ACL) reconstruction (ACLR) leads to additional morbidity in adults.

Purpose

To determine the 5-year incidence of and risk factors for PTOA diagnoses after primary ACLR in pediatric patients.

Study Design

Case control study, Level of evidence, 3.

Methods

A United States-based insurance database was used to identify patients aged ≤16 years who underwent primary ACLR from 2010 to 2019 and had at least 5 years of follow-up data. Patients with multiligament knee injuries, tibial eminence avulsion fractures, congenital/syndromic ACL absence syndrome, juvenile idiopathic arthritis, previous knee osteoarthritis or PTOA diagnoses, or previous knee injuries/surgeries were excluded. Demographic factors and concomitant meniscal and cartilage procedures at the time of primary ACLR were recorded. Delayed ACLR was defined as ≥3 months between initial ACL injury diagnosis and ACLR. We also recorded the presence of subsequent motion restoration reoperations, including lysis of adhesions and/or manipulation under anesthesia, after primary ACLR but before PTOA diagnosis. Risk factors for PTOA were evaluated using multivariable logistic regression.

Results

Included were 16,935 patients (mean age at surgery, 15.1 ± 1.2 years; 62% women). PTOA was diagnosed in 267 patients (1.6%) within 5 years after ACLR; 148 of these patients (55.4%) were diagnosed within 2 years after ACLR. Independent risk factors associated with PTOA diagnosis included subsequent motion restoration procedures (odds ratio [OR], 5.03 [95% CI, 3.31-8.25]; P < .001), age ≥12 years at the time of ACLR (OR, 4.82 [95% CI, 1.54-29.20]; P = .027), delayed ACLR (OR, 1.87 [95% CI, 1.43-2.43]; P < .001), obesity (OR, 1.40 [95% CI, 1.01-1.94]; P = .046), and male sex (OR, 1.36 [95% CI, 1.06-1.74]; P = .015). Performing concomitant partial meniscectomy, meniscus repair, and cartilage restoration at the time of ACLR was not significantly associated with PTOA.

Conclusion

The incidence of PTOA diagnoses was low within 5 years after primary ACLR in patients ≤16 years old with no subsequent cartilage, meniscus, and/or revision ligament procedures. The need for subsequent motion restoration procedures, age ≥12 years at the time of ACLR, delayed ACLR, obesity, and male sex were significant risk factors associated with a PTOA diagnosis.

Performance effects of functional knee brace removal and prolonged use in healthy male athlete: Lower extremity power, acceleration, speed, and agility

OBJECTIVES

Knee braces were introduced to sports 30 years ago. However, knee brace use for non-contact anterior cruciate ligament injury prevention intervention remains contentious due to concerns about performance hindrances. Since knee brace use is a potential modifiable risk factor, we aimed to investigate the effect of discounting and continued functional knee brace (FKB) on lower extremity power-vertical jump (VJ), acceleration, speed, and agility performance.

DESIGN

Prospective cohort crossover study.

METHODS

Twenty-seven healthy male athletes performed seven tests, over six days of 12 test sessions (S), during three test conditions (non-braced, braced, and removed brace or continued brace use). This study focuses on VJ, acceleration, speed, and agility performance during S12 when athletes were randomly selected to remove the FKB after 17.5 h or continue using the FKB for 21.0 h.

RESULTS

After brace removal, nonsignificant performance levels improved in the VJ (2.7 %; 95 % CI 52.5-62.8; Cohen's effect size (ES) = trivial), acceleration (1.8 %; 95 % CI 0.500-0.562; ES = small), and agility (0.5 %; 95 % CI 9.25-10.13; ES = trivial), while a nonsignificant slower speed was recorded (0.5 %; 95 % CI 1.81-1.95; ES = trivial). Continued brace use led to a nonsignificant performance improvement in all tests; VJ (3.1 %; 95 % CI 53.5-60.2; ES = small), acceleration (1.5 %; 95 % CI 0.511-0.561; ES = trivial), speed (1.0 %; 95 % CI 1.83-1.95; ES = trivial), and agility (1.8 %; 95 % CI 9.26-10.04; ES = trivial).

CONCLUSIONS

Removal of FKB led to improved performance in three performance tests, while continued brace use improved performance in all four tests.

Antioxidant taurine inhibits chondrocyte ferroptosis through upregulation of OGT/Gpx4 signaling in osteoarthritis induced by anterior cruciate ligament transection

OBJECTIVE

The aim of this study was to investigate the potential molecular mechanisms by which taurine protects against cartilage degeneration.

METHODS

The anterior cruciate ligament transection (ACLT) surgery was used to construct an animal model of osteoarthritis (OA). Metabolomics was used to identify characteristic metabolites in osteoarthritic chondrocytes. Transcriptomics and metabolomics were used to explore potential mechanisms by which the small molecule metabolite taurine protects against inflammatory chondrocyte damage. Cell transfection and small molecule inhibitors/agonists were used to validate the molecular mechanisms by which taurine protects inflammatory chondrocytes in vitro. Finally, adeno-associated virus and small molecule inhibitors/agonists were used to validate the molecular mechanisms by which taurine protects against cartilage degeneration in vivo.

RESULTS

Metabolomic assays identified taurine as a possible key metabolic molecule in the progression of OA. Transcriptomics and metabolomics revealed that O-GlcNAc transferase (OGT)-dependent O-GlcNAcylation and Gpx4-dependent ferroptosis may mediate the inflammatory protective effects of taurine on chondrocytes, which was further confirmed by gain and loss of function in vitro. Subsequently, further experiments indicated that the possible existence of a direct binding site for Gpx4 and OGT proteins, which provides evidence for the presence of O-GlcNAc modification of Gpx4 protein. Finnaly, we demonstrated that Gpx4-dependent ferroptosis and OGT-dependent O-GlcNAcylation may be potential mechanisms by which taurine protects against cartilage degeneration in vivo.

CONCLUSION

Antioxidant taurine inhibits chondrocyte ferroptosis through upregulation of OGT/Gpx4 signaling. Supplementation with taurine, a safe nonessential amino acid, may be a potential therapeutic strategy for OA.

Osteoarthritis

Osteoarthritis is a heterogeneous disorder that is increasingly prevalent largely due to aging and obesity, resulting in a major disease burden worldwide. Knowledge about the underlying aetiology has improved, with increased understanding of the role of genetic factors, the microbiome, and existence of different pain mechanisms. However, this knowledge has not yet been translated into new treatment options. New evidence has questioned the efficacy of recommended treatments, such as therapeutic exercise programmes and the focus on weight loss, but managing obesity and maintaining activity remain important for the prevention and management of osteoarthritis. Approaches should consider individual and cultural preferences and resource availability to increase patient and community engagement, and optimise outcomes worldwide. Most of the focus has been on established osteoarthritis where management is primarily directed at relieving symptoms. The search for the much needed effective treatments that improve both symptoms and structure, often referred to as disease-modifying osteoarthritic drugs, is ongoing. Promising data indicate that targeting inflammation is effective in hand osteoarthritis.

Current advances in animal model of meniscal injury: From meniscal injury to osteoarthritis

Meniscal injury is a prevalent orthopedic practice that causes articular cartilage wear and degeneration due to tissue damage or loss, and may eventually result in the occurrence of knee osteoarthritis (KOA). Hence, investigating the structural regeneration and mechanical function restoration of the meniscus after injury is pivotal research topic for preventing KOA. Animal models are essential for investigating therapeutic strategies for meniscal injuries and their clinical translation, yet no current model can fully recapitulate the complexity of human meniscal injuries. This review aims to categorize the prevalent animal models of meniscal injury by their establishment methods, elucidate their principles and procedures, and discuss the suitability and limitations of each model. We delineate the pros and cons of different models in simulating the pathology and biomechanics of human meniscal injury. We also analyze different animal species regarding their meniscal structure, function, and repair potential, and their implications for model selection. We conclude that selecting an appropriate animal model requires a comprehensive consideration of various factors, such as research aims, anticipated outcomes, and feasibility. Furthermore, to translate novel therapeutic approaches to clinical applications more safely and effectively, future model development should emphasize aspects such as choosing animals of suitable age. The Translational Potential of this Article: This review aims to categorize and discuss current animal models of meniscal injury by establishment methods and provides a comprehensive overview of the routinely employed experimental animals in each model to facilitate the clinical translation of OA-related research.

A dynamic knee function scoring system for anterior cruciate ligament injuries based on normative six-degree-of-freedom gait pattern

BACKGROUND

Traditional examinations of anterior cruciate ligament (ACL) injuries focus primarily on static assessments and lack the ability to evaluate dynamic knee stability. Hence, a dynamic scoring system for knee function is needed in clinical settings. This study aimed to propose a dynamic scoring system based on a large sample of normative six-degree-of-freedom (6-DOF) knee kinematics during gait, and validate its correlation with conventional outcome measurements in assessing ACL-injured knees.

METHODS

A total of 500 healthy Chinese participants were enrolled to establish a large dataset. The 6-DOF kinematics of both knees during gait were recorded using an infrared navigation three-dimensional portable knee motion analysis system. Based on the large sample dataset, a novel 6-DOF scoring system was developed using the dynamic time warping algorithm. To further validate the scoring system, an additional 83 patients with ACL injuries were included, and their preoperative dynamic knee kinematics assessment and patient-reported outcome measurements (PROMs) were recorded. Spearman's correlation coefficient (ρ) was used to determine the correlations between the 6-DOF score and the Lysholm score, International Knee Documentation Committee (IKDC) subjective score, and Tegner activity scale.

RESULTS

The mean values of adduction/abduction, internal/external rotation, flexion/extension, anterior/posterior translation, proximal/distal translation, and medial/lateral translation in the 500 healthy participants were 10.07 ± 4.04°, 15.13 ± 4.85°, 60.56 ± 6.07°, 1.79 ± 0.75 cm, 1.58 ± 0.54 cm, and 1.10 ± 0.42 cm, respectively. The mean preoperative 6-DOF score, Lysholm score, IKDC subjective score, and Tegner activity scale of the 83 ACL-injured patients were 74.29 ± 7.23, 70.26 ± 17.55, 66.78 ± 15.79, and 2.28 ± 1.56, respectively. The 6-DOF score was significantly correlated with the Lysholm score (ρ = 0.375, P < 0.001) and Tegner activity scale (ρ = 0.273, P = 0.016) for the ACL-injured patients. No significant correlation was found between the 6-DOF score and the IKDC subjective score (ρ = 0.145, P = 0.208).

CONCLUSION

This study proposed a normative 6-DOF knee kinematic reference range for the Chinese population based on a large sample dataset. The 6-DOF dynamic score was developed accordingly and proven to be significantly correlated with the Lysholm score and the Tegner activity scale, showing the potential to provide comprehensive and meaningful information on dynamic knee function and stability for patients with ACL injuries in the future.

Health problems and injury management in adolescent handball: the Safeplay one-season cohort study of 679 players

OBJECTIVES

To assess (1) the 1-year prevalence of previous shoulder, knee and ankle injuries; (2) the in-season prevalence proportion (prevalence) of injuries and illnesses, injury incidence rate (ir) and injury burden (product of ir and weeks with injuries); (3) initial injury management strategies.

METHODS

We conducted a cohort study of 679 highest-division Danish handball players aged 14-18. Players self-reported past-year shoulder, knee and ankle injuries at baseline, and weekly information on any handball-related injuries (irrespective of time loss and medical attention), illnesses, exposure hours and injury management over 31 weeks.

RESULTS

At baseline, 46% (95% CI 42% to 49%) of the players reported a past-year shoulder, knee or ankle injury. The weekly average injury and illness prevalence was 21% (95% CI 19% to 23%) and 2% (95% CI 1.7% to 2.3%), respectively, and the ir was 9.4 (95% CI 8.7 to 10.2)/1000 hours. Females experienced the highest injury burden from knee injuries (ir: 1.7 (95% CI 1.3 to 2.2) × 6.7 (95% CI 4.7 to 8.7) weeks with injury/1000 hours), while males experienced the highest injury burden from shoulder injuries (ir: 1.3 (95% CI 1.0 to 1.7) × 5.7 (95% CI 3.6 to 7.8) weeks with injury/1000 hours). Health professionals were consulted in 58% (95% CI 54% to 62%) of injuries, players independently made the return to sport decision in 44% (95% CI 37% to 51%) of injury recurrences, and used analgesics, mainly (91% (95% CI 85% to 95%)) sourced from home, in 24% (95% CI 21% to 28%) of injuries.

CONCLUSION

Almost half of highest-division adolescent Danish handball players reported a previous past-year shoulder, knee or ankle injury. Any time during the season, 21% reported an injury and 2% an illness. The highest injury burdens were from knee injuries in females and shoulder injuries in males. Health professionals often managed injuries, but players frequently made return to sport decisions independently and commonly used analgesics sourced from home.

Injury prevention programmes (IPPs) for preventing anterior cruciate ligament injuries

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To determine the benefits and harms of injury prevention programmes on anterior cruciate ligament injuries.

Mechanical Signal Transduction: A Key Role of Fluid Shear Forces in the Development of Osteoarthritis

Globally, osteoarthritis is a common and highly disabling disease that places a heavy burden on society and medical systems. The role of biomechanical factors in the development of osteoarthritis has gradually received more attention. As a key biomechanical stimulus, fluid shear force is becoming the focus of research for its dual role in maintaining cartilage health and disease progression. This paper conducts an in-depth discussion on the mechanism of fluid shear force in osteoarthritis and its impact on the disease process, aiming to reveal how fluid shear stress affects the development of osteoarthritis by regulating the physiological function and signal transduction pathways of chondrocytes.

The potential of tendon autograft as meniscus substitution: Current concepts

Meniscectomy is known to alter the mechanics, stability, and kinematics of the tibiofemoral joint, leading to early knee osteoarthritis (KOA). While several meniscal substitutions exist, such as meniscus allograft transplantation, collagen meniscus implants, and artificial substitutes, they often come with technical challenges, high costs, and risks, including allograft failure, infections, and disease transmission. Tendon autografts emerge as a promising option, offering safety, availability, biocompatibility, and a reduced risk of pathophoresis. This review delves into basic, in vivo, in vitro, and biomechanical studies alongside clinical outcomes and future prospects of tendon autografts as meniscus substitutes. A thorough understanding of this option is vital for integrating these evolving techniques into clinical practice and mitigating early KOA progression.

Reparative homing of bone mesenchymal stem cells induced by iMSCs via the SDF-1/CXCR4 axis for articular cartilage defect restoration

BACKGROUND

The intrinsic healing ability of articular cartilage is poor after injury or illness, and untreated injury could lead to cartilage degeneration and ultimately osteoarthritis. iMSCs are derived from embryonic induced pluripotent stem cells and have strong therapeutic capabilities in the repair of cartilage defects, while the mechanism of action is unclear. The aim of this study is to clarify the repair mode of iMSCs on cartilage defects in rat knee joints, elucidate the chemotactic effect of iMSCs on autologous BMSCs in rats, and provide a basis for the treatment of cartilage defects and endogenous regeneration with iMSCs.

METHODS

Based on the establishment of the rat cartilage defect model, the reparative effect of iMSCs on the rat cartilage defect was evaluated. The cartilage repair was evaluated by quantitative score, H&E staining, Masson staining and Safranin-O staining, and the metabolic changes of iMSCs in the joint cavity were detected in vivo. The expression of SOX9, CD29, CD90, ColⅠ, ColⅡ, PCNA, SDF-1, and CXCR4 was detected by immunohistochemistry (IHC), IF, flow cytometry, respectively. After co-culturing iMSCs with BMSCs in vitro, the expression of CXCR4/SDF-1 on the cell membrane surface of BMSCs was detected by western blotting.; The level of p-Akt and p-Erk1/2 in total protein of BMSCs were detected by western blotting.

SIGNIFICANCE

Our research results provide experimental evidence for the treatment of cartilage defects and endogenous regeneration with iMSCs; This also provides new ideas for the clinical treatment of cartilage defects using iMSCs.

Jump performance and movement quality in 7- to 15-year-old competitive alpine skiers: a cross-sectional study

INTRODUCTION

Injury rates in competitive alpine skiing are high. With current methods, identifying people at risk is expensive and thus often not feasible at the youth level. The aims of this study were (1) to describe the jump performance and movement quality of youth competitive alpine skiers according to age and sex, (2) to compare the jump distance among skiers of different sexes and movement quality grades, and (3) to assess the inter-rater grading reliability of the qualitative visual movement quality classification of such jumps and the agreement between live and video-based post-exercise grading.

MATERIALS AND METHODS

This cross-sectional study is based on an anonymized dataset of 301 7- to 15-year-old competitive alpine skiers. The skiers performed two-legged forward triple jumps, whereby the jump distance was measured, and grades were assigned by experienced raters from the frontal and sagittal perspectives depending on the execution quality of the jumps. Furthermore, jumps were filmed and ultimately rated post-exercise. Differences in jump distance between various groups were assessed by multivariate analyses of variance (MANOVAs). Reliability was determined using Kendall's coefficient of concordance.

RESULTS

The jump distance was significantly greater in U16 skiers than in U11 skiers of both sexes and in skiers with good execution quality than in those with reduced or poor execution quality. Overall, jump distance in U16 skiers significantly differed between female (5.37 m with 95% CI [5.21, 5.53]) and male skiers (5.90 m with 95%CI [5.69, 6.10]). Slightly better inter-rater grading reliability was observed for video-based post-exercise (strong agreement) ratings than for live ratings (moderate agreement).

CONCLUSION

In competitive alpine skiers aged 7 to 15 years, jump performance increases with age, and around puberty, sex differences start to manifest. Our results highlight the importance of evaluating both jump distance and movement quality in youth skiers. To improve test-retest reliability, however, a video-based post-exercise evaluation is recommended.

Nanomaterials: Recent Advances in Knee Osteoarthritis Treatment

Osteoarthritis (OA) of the knee is the most prevalent degenerative joint condition that places a substantial financial and medical burden on society. However, due to drawbacks such as inefficiency, adverse effects, and brief duration of action, the clinical efficacy of the current major therapies for knee OA is largely restricted. Therefore, novel medication development is highly required to address these issues. Numerous studies in recent years have established that nanomaterials can be a potential and highly effective way to overcome these challenges. In this review, the anatomical distinctions between healthy and OA knee joints, as well as novel advances in the field of nanomaterials for the treatment of knee OA are summarized. The limits of the present therapeutic strategies for treating knee OA are also highlighted, as well as the potential prospects of nanomaterials in the future.

Impact of prior knee surgery on change in knee pain, quality of life, and walking speed following supervised education and exercise therapy: an analysis of 30,545 people with knee osteoarthritis

To investigate the impact of prior knee surgery on changes in outcomes following an 8-week supervised patient education and exercise therapy program in patients with knee osteoarthritis. Patients were classified according to knee surgery in the most affected knee joint (yes/no) prior to enrolment in the Good Life with osteoArthritis in Denmark (GLA:D®) program. Between-group differences in outcome changes from baseline to 3 months follow-up were evaluated using linear regression stratified by sex. Outcomes were knee pain intensity (VAS, 0-100 mm), joint related quality of life (Knee Injury and Osteoarthritis Outcome Score Quality of Life subscale score (KOOS QOL, 0-100)) and walking speed (40-m fast-paced walk test). To evaluate clinically relevant between-group differences, proportions of patients reaching a threshold of minimal important change in the surgery and non-surgery groups were compared. Among 30,545 patients, 27% (n, 8254) had prior surgery in the most affected knee. The prior surgery and the non-surgery group experienced improvements in all outcomes with minor between-group differences in change in pain intensity (males, 0.03 95% CI - 0.9 to 1.0; females, 1.3 95% CI 0.6 to 2.1); KOOS QOL (males, 0.3 95% CI - 0.4 to 0.9; females 0.02 95% CI - 0.5 to 0.5); and walking speed (males, 0.01 95% CI - 0.01 to 0.02; females 0.01 95% CI 0.003 to 0.02). The responder analysis showed no clinically relevant between-group differences in improvements. Previous knee surgery does not seem to modify the clinical outcome following exercise therapy and patient education in patients with knee osteoarthritis.

Evaluation of a time-varying cut-off frequency low-pass filter for assessing knee joint moments and ACL injury risk

Conventional low-pass filtering of 3D motion capture signals prior to estimating knee joint moments and ACL injury risk has known limitations. This study aimed to evaluate the fractional Fourier filter (FrFF), which employs a time-varying cut-off frequency, for assessing peak knee moments during common ACL injury risk screening tasks. Ground reaction force and motion data were collected from 23 team sport athletes performing 45° unanticipated sidesteps and drop jumps. Peak knee abduction, internal rotation and non-sagittal moments were estimated using inverse dynamics after five different low-pass filter approaches were applied (FrFF vs. four variations of a fourth-order Butterworth filter). The FrFF produced peak knee moments larger than "matched" (i.e. force and motion cut-off frequencies were equivalent) and closer to "unmatched" (i.e. force and motion cut-offs were different) Butterworth filter approaches and removed problems with representing foot-to-ground impact peaks. Participants with larger peak moments were identified as "at risk" of injury irrespective of filter approach, but the FrFF identified "at risk" classifications conventional approaches did not. Preliminary evidence suggests that the FrFF displays enhanced sensitivity to movement strategies that induce high knee loads. This was most evident for sidestepping, with more research warranted to optimise the FrFF for drop jumps.

Robust tetra-armed poly (ethylene glycol)-based hydrogel as tissue bioadhesive for the efficient repair of meniscus tears

Repair and preservation of the injured meniscus has become paramount in clinical practice. However, the complexities of various clinic stitching techniques for meniscus repair pose challenges for grassroots doctors. Hence, there is a compelling interest in innovative therapeutic strategies such as bioadhesives. An ideal bioadhesive must cure quickly in aqueous and blood environments, bind strongly, endure arthroscopic washing pressures, and degrade appropriately for tissue regeneration. Here, we present a tetra-poly (ethylene glycol) (PEG)-based hydrogel bioadhesive, boasting high biocompatibility, ultrafast gelation, facile injectable operation, and favorable mechanical strength. In view of the synergistic effects of chemical anchor and physical chain entanglement to tightly bind the meniscus, a seamless interface was formed between the surrounding meniscal tissues and hydrogels, enabling the longitudinal tear of the meniscus fused in situ to withstand large tensile force with the adhesive strength of 541.5 ± 31.4 kPa and arthroscopic washout resistance of 29.4 kPa. Superior to existing commercial adhesives, ours allows sutureless application and arthroscopic assistance, without requiring specialized clinical skills. This research is expected to significantly impact our understanding of meniscal healing and ultimately promote a simpler process for achieving functional and structural recovery in torn menisci.

Health And Performance Promotion in Youth (HAPPY) hybrid effectiveness-implementation cluster randomised trial: comparison of two strategies to implement an injury prevention exercise programme in Danish youth handball

OBJECTIVE

To investigate if a combination of an online and onsite implementation strategy was superior to an online-only strategy in enhancing the use of an injury prevention exercise programme (IPEP) and in reducing the risk of shoulder, knee and ankle injuries in youth community handball players (age 11-17) over a handball season.

METHODS

In this 30-week hybrid effectiveness-implementation cluster randomised type 3 study, 20 youth handball clubs were randomly assigned 1:1 to either a combined online and onsite implementation strategy (coach workshop using the health action process approach behaviour change model and health service provider (HSP) support) or an online-only strategy (control group). The primary implementation outcome was coach-reported adherence, measured as the average IPEP exercise usage by the team over 30 weeks. The primary effectiveness outcome was player-reported handball playing time to any new handball-related shoulder, knee and ankle injuries, reported weekly using the Oslo Sports Trauma Research Centre Questionnaire on Health Problems.

RESULTS

We enrolled 63 coaches (27% women) and 945 players (mean age 14.5 years, 55% girls). Intention-to-treat analyses showed no statistically significant difference between implementation strategies in adherence (between-group difference 1.4, 95% CI -0.5 to 3.4) or in cumulative injury risk (between-group difference 5.5% points, 95% CI -2.2 to 13.1).

CONCLUSION

Our findings demonstrate that in youth community handball, a combined online and onsite implementation strategy, including a coach workshop and HSP support, was not superior to an online-only strategy regarding adherence to an IPEP or in reducing shoulder, knee and ankle injury risk.

TRIAL REGISTRATION NUMBER

NCT05294237.

Anterior Cruciate Ligament Tear: Individualized Indications for Non-Operative Management

Anterior cruciate ligament (ACL) rupture represents a common sports injury that is mostly managed operatively. However, non-operative treatment can also play a role, despite the limited high-quality published data on ACL tear management. Both methods have shown favorable outcomes, but clear guidelines based on high-quality research are lacking. Several factors should be considered and discussed with the patient before deciding on the best treatment method. These include patient characteristics and expectations, concomitant injuries, and clinical evaluation, with laxity or/and instability being one of the most essential parameters examined. This should eventually lead to an individualized approach for each patient to ensure the best possible outcome. This review aims to delve into all parameters that are related to ACL rupture and guide physicians in choosing the most appropriate treatment method for each patient.

Clinical Utility of Qualitative Change of Direction Movement Assessment in ACL Injury Risk Evaluation

Anterior cruciate ligament (ACL) injuries are complex and influenced by numerous internal and external risk factors that should be considered to effectively mitigate injury and facilitate informed return to sport decision-making. Among these risk factors, movement quality exhibited during sport-specific tasks has been identified as a significant predictor of injury occurrence. Particularly, change of direction (COD) movements, when performed with sub-optimal movement quality, such as knee valgus and lateral trunk flexion, are prominent mechanisms of ACL injury in multidirectional sports. Unfortunately, the formal and objective assessment of COD movement quality is underutilized in clinical and sports practice, with existing methods often confined to expensive, sophisticated laboratory settings impractical for everyday clinicians. The purpose of this clinical commentary is to demonstrate the necessity of integrating COD movement assessments to screen for potential ACL injury risk, particularly among higher-risk populations. The authors will review cost-effective and clinic-friendly objective tests used to qualitatively screen COD movements, such as the Cutting Movement Assessment Score and The Expanded Cutting Alignment Tool. Additionally, this commentary will discuss key considerations when assessing COD movement.

Level of Evidence

5.

Vitamin D Deficiency after Anterior Cruciate Ligament Reconstruction Associates with Knee Osteoarthritis: A Retrospective Study

BACKGROUND/OBJECTIVES

The objective of this study was to test the hypothesis that vitamin D deficiency (i.e., serum 25-hydroxyvitamin D (25(OH)D) ≤ 20 ng/mL) associates with the increased occurrence and shortened time to a knee osteoarthritis (OA) diagnosis after anterior cruciate ligament reconstruction (ACLR).

METHODS

This study consisted of a retrospective, case-control design. The inclusion criteria consisted of (1) patients (≥18 y) who underwent arthroscopic ACLR with (cases; n = 28) and without (controls; n = 56) a subsequent knee OA diagnosis (≥90 d from the date of ACLR) and (2) with a documented serum 25(OH)D concentration after ACLR (and before a knee OA diagnosis for the cases). Controls were matched (2:1) to cases based on sex, age at ACLR, date of ACLR, and body mass index. After matching, patients were separated into two groups: (1) vitamin D deficient (serum 25(OH)D ≤ 20 ng/mL) or (2) non-vitamin D deficient (serum 25(OH)D > 20 ng/mL). Data were extracted from the medical records.

RESULTS

Thirty-one percent (n = 26) of patients included were vitamin D deficient. Fifty percent (n = 13) of the vitamin D deficient and twenty-six percent (n = 15) of the non-vitamin D deficient patients were subsequently diagnosed with knee OA (p = 0.03). Time from ACLR to a knee OA diagnosis was significantly (p = 0.02) decreased in the vitamin D deficient (OA-free interval, 95% confidence interval [CI] = 7.9 to 10.9 y) compared to the non-vitamin D deficient group (OA-free interval, 95% CI = 10.5 to 12.5 y).

CONCLUSIONS

Vitamin D deficiency after ACLR may serve as a prognostic biomarker for knee OA following ACLR.

X-ray with finite element analysis is a viable alternative for MRI to predict knee osteoarthritis: Data from the Osteoarthritis Initiative

Magnetic resonance imaging (MRI) offers superior soft tissue contrast compared to clinical X-ray imaging methods, while also providing accurate three-dimensional (3D) geometries, it could be reasoned to be the best imaging modality to create 3D finite element (FE) geometries of the knee joint. However, MRI may not necessarily be superior for making tissue-level FE simulations of internal stress distributions within knee joint, which can be utilized to calculate subject-specific risk for the onset and development of knee osteoarthritis (KOA). Specifically, MRI does not provide any information about tissue stiffness, as the imaging is usually performed with the patient lying on their back. In contrast, native X-rays taken while the patient is standing indirectly reveal information of the overall health of the knee that is not seen in MRI. To determine the feasibility of X-ray workflow to generate FE models based on the baseline information (clinical image data and subject characteristics), we compared MRI and X-ray-based simulations of volumetric cartilage degenerations (N = 1213) against 8-year follow-up data. The results suggest that X-ray-based predictions of KOA are at least as good as MRI-based predictions for subjects with no previous knee injuries. This finding may have important implications for preventive care, as X-ray imaging is much more accessible than MRI.

Lower Limb Joint Mechanics during Maximal Accelerative and Decelerative Running

INTRODUCTION

Maximal acceleration and deceleration tasks are frequently required in team sports, often occurring rapidly in response to external stimuli. Accelerating and decelerating can be associated with lower limb injuries; thus, knowledge of joint mechanics during these tasks can improve the understanding of both human high performance and injury mechanisms. The current study investigated the fundamental differences in lower limb joint mechanics when accelerating and decelerating by directly comparing the hip, knee, and ankle joint moments and work done between the two tasks.

METHODS

Twenty participants performed maximal effort acceleration and deceleration trials, with three-dimensional marker trajectories and ground reaction forces collected simultaneously. Experimental data were combined with inverse dynamics analysis to compute joint moments and work.

RESULTS

Net joint work for all lower limb joints was positive during acceleration and negative during deceleration. This occurred because of significantly greater positive work production from the ankle and hip during acceleration and significantly greater negative work production from all joints during deceleration. The largest contributions to positive work during acceleration came from the ankle, followed by the hip and knee joints, whereas the largest contributions to negative work during deceleration came from the knee and hip joints, followed by the ankle. Peak joint moments were significantly greater when decelerating compared with accelerating, except for the peak ankle plantarflexion and hip flexion moments, which were significantly greater when accelerating.

CONCLUSIONS

Our findings may help to guide training interventions, which aim to enhance the performance of acceleration and deceleration tasks, while also mitigating the associated injury risk.

People with painful knee osteoarthritis hold negative implicit attitudes towards activity

ABSTRACT

Negative attitudes/beliefs surrounding osteoarthritis, pain, and activity contribute to reduced physical activity in people with knee osteoarthritis (KOA). These attitudes/beliefs are assessed using self-report questionnaires, relying on information one is consciously aware of and willing to disclose. Automatic (ie, implicit) assessment of attitudes does not rely on conscious reflection and may identify features unique from self-report. We developed an implicit association test that explored associations between images of a person moving/twisting their knee (activity) or sitting/standing (rest), and perceived threat (safe vs dangerous). We hypothesised that people with KOA would have greater implicit threat-activity associations (vs pain-free and non-knee pain controls), with implicit attitudes only weakly correlating with self-reported measures (pain knowledge, osteoarthritis/pain/activity beliefs, fear of movement). Participants (n = 558) completed an online survey: 223 had painful KOA (n = 157 female, 64.5 ± 8.9 years); 207 were pain free (n = 157 female, 49.3 ± 15.3 years); and 99 had non-KOA lower limb pain (n = 74 female, 47.5 ± 15.04 years). An implicit association between "danger" and "activity" was present in those with and without limb pain (KOA: 0.36, 95% CI 0.28-0.44; pain free: 0.13, 95% CI 0.04-0.22; non-KOA lower limb pain 0.11, 95% CI -0.03 to 0.24) but was significantly greater in the KOA group than in the pain free ( P < 0.001) and non-KOA lower limb pain ( P = 0.004) groups. Correlations between implicit and self-reported measures were nonsignificant or weak (rho = -0.29 to 0.19, P < 0.001 to P = 0.767). People with painful KOA hold heightened implicit threat-activity associations, capturing information unique to that from self-report questionnaires. Evaluating links between implicit threat-activity associations and real-world behaviour, including physical activity levels, is warranted.

Four-year comparative analysis of return to sport and psychological recovery following ACL revision: Artificial ligament vs. anterior tibial tendon allograft

Background

Research on return to sport and psychological recovery in anterior cruciate ligament (ACL) revision remains scarce. The clinical efficacy of artificial ligament in ACL revision requires further exploration. Our objectives were (1) to compare the midterm clinical outcomes of artificial ligament versus allogenic tendon graft in ACL revision and (2) to analyze the effects of employing artificial ligament on return to sport and psychological recovery in ACL revision.

Methods

This cohort study included the cases receiving ACL revision from 2014 to 2021 in Sports Medicine Department of Huashan Hospital. The grafts used were Ligament Advanced Reinforcement System (LARS) and ATT allograft. We recorded patients' baseline data. The final follow-up assessment included subjective scales, physical examination, and return to sport status. We recorded the rates and timings of return to sport. Subjective scales included the 2000 International Knee Documentation Committee (IKDC) subjective score, Lysholm Knee Scaling Score (LKSS), Knee injury and Osteoarthritis Outcome Score (KOOS), Tegner activity score, Marx activity rating score, and Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI). Anterior knee stability was assessed using the KT-1000 arthrometer.

Results

Fifty cases (LARS group: 27; ATT group: 23) enrolled and 45 (LARS group: 23; ATT group: 22) completed evaluations with a median follow-up period of 49 months. At recent follow-up, LARS group outperformed in knee stability (1.0 ± 1.9 mm vs. 2.6 ± 3.0 mm, P = 0.039), confidence (86.7 ± 12.4 vs. 69.4 ± 18.6, P < 0.001), emotion (82.7 ± 11.3 vs. 70.7 ± 16.2, P < 0.001), KOOS knee function (78.7 ± 8.8 vs. 69.5 ± 11.0, P = 0.003), quality of life (79.1 ± 16.1 vs. 66.4 ± 19.5, P = 0.014), Tegner score (6.3 ± 1.9 vs. 5.2 ± 2.1, P < 0.001), and Marx activity score (10.7 ± 3.7 vs. 7.9 ± 4.0, P = 0.012). The LARS group had significantly higher return rates: recreational (91.3 % vs. 63.6 %, P = 0.026), knee cutting and pivoting (87.0 % vs. 59.1 %, P = 0.035), competitive (78.3 % vs. 45.5 %, P = 0.023), and pre-injury (56.5 % vs. 27.3 %, P = 0.047). For return timings, the LARS group was earlier at recreational (11.2 ± 3.9 vs. 27.8 ± 9.0 weeks, P < 0.001), knee cutting and pivoting (17.2 ± 5.8 vs. 35.6 ± 13.8 weeks, P < 0.001), competitive (24.8 ± 16.2 vs. 53.2 ± 22.0 weeks, P < 0.001), and pre-injury levels (32.8 ± 11.0 vs. 72.8 ± 16.9 weeks, P < 0.001).

Conclusion

In ACL revision, using LARS demonstrated improved joint stability and functionality compared to using allogenic ATT four years postoperative. Patients accepting the LARS procedure exhibited higher rates and earlier timings of return to various levels of sport, indicating enhanced confidence and emotional resilience.

The translational potential of this article

In ACL revision, the choice of artificial ligament to shorten recovery time, thereby enabling patients to return to sport more quickly and effectively, is thought-provoking. The research value extends beyond mere graft selection, guiding future clinical trials and studies. This research enhances our understanding of the application value of artificial ligament in ACL revision, emphasizing the importance of psychological recovery and updating our perceptions of return to sport levels post-revision. It stimulates exploration into personalized rehabilitation programs and treatment strategies, aiming to optimize clinical outcomes and meet the real-world needs of patients with failed ACL reconstruction.

Multicomponent supervised tele-rehabilitation versus home-based self-rehabilitation management after anterior cruciate ligament reconstruction: a study protocol for a randomized controlled trial

INTRODUCTION

Our study aims to assess the effectiveness of multicomponent supervised tele-rehabilitation compared to home-based self-rehabilitation management in patients following anterior cruciate ligament reconstruction (ACLR).

METHODS

The current study is designed as a single-center, single-blinded, randomized controlled, two-arm trial. Participants will be randomized and allocated at a 1:1 ratio into either a multicomponent supervised tele-rehabilitation group or a home-based self-rehabilitation group. All participants receive uniform preoperative education through the HJT software. Participants in the intervention group undergo multicomponent supervised tele-rehabilitation, while those in the control group follow a home-based self-rehabilitation program. All the participants were assessed and measured for the included outcomes at the outpatient clinic before the procedure, and in 2, 4, 8, 12, and 24 weeks after ACLR by two assessors. The primary outcome was the percentage of patients who achieve a satisfactory active ROM at the 12 weeks following the ACLR. The satisfactory active ROM was also collected at 2, 4, 8, and 24 weeks after ACLR. The secondary outcomes were active and passive range of motion (ROM), pain, muscle strength, and function results.

REGISTRATION DETAILS

Ethical approval has been obtained from the West China Hospital Ethics Committee (approval number 2023-1929, December 2023). The trial has been registered on ClinicalTrials.gov (registration number NCT06232824, January 2024).

Alterations in DNA methylation machinery in a rat model of osteoarthritis of the hip

BACKGROUND

This study aimed to validate alterations in the gene expression of DNA methylation-related enzymes and global methylation in the peripheral blood mononuclear cell (PBMC) and synovial tissues of animal hip osteoarthritis (OA) models.

METHODS

Animals were assigned to the control (no treatment), sham (25 µL of sterile saline), and OA (25 µL of sterile saline and 2 mg of monoiodoacetate) groups. Microcomputed tomography scan, histopathological assessment and pain threshold measurement were performed after induction. The mRNA expression of the DNA methylation machinery genes and global DNA methylation in the PBMC and hip synovial tissue were evaluated.

RESULTS

The OA group presented with hip joint OA histopathologically and radiologically and decreased pain threshold. The mRNA expression of DNA methyltransferase (Dnmt 3a), ten-eleven translocation (Tet) 1 and Tet 3 in the synovial tissue of the OA group was significantly upregulated. Global DNA methylation in the synovial tissue of the OA group was significantly higher than that of the control and sham groups.

CONCLUSIONS

The intra-articular administration of monoiodoacetate induced hip joint OA and decreased pain threshold. The DNA methylation machinery in the synovial tissues of hip OA was altered.

Magnetic resonance imaging shows low sensitivity but good specificity in detecting ramp lesions in children and adolescents with ACL injury: A systematic review

IMPORTANCE

The diagnosis of ramp lesions can be problematic, even with arthroscopy, due to their extreme posteromedial position. Consequently, they have been colloquially referred to as the "hidden lesions" of the knee. Undiagnosed and untreated injuries in this knee region may be associated with ongoing dynamic rotational laxity of the knee after anterior cruciate ligament reconstruction and an increased risk of anterior cruciate ligament graft failure.

AIM

This study aimed to systematically review the literature to assess the sensitivity, specificity and accuracy of magnetic resonance imaging (MRI) for detecting ramp lesions in children and adolescents with anterior cruciate ligament (ACL)-deficient knees. It was hypothesized that MRI has poor sensitivity for identifying ramp lesions in children and adolescents.

EVIDENCE REVIEW

A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following search terms were used in the title, abstract and keywords fields: "ramp" or "meniscus" AND "children" or "adolescents." The outcome data extracted from the studies were incidence of ramp in concomitant with ACL lesion, MRI sensitivity, specificity, accuracy and positive and negative predictive values (PPV and NPV).

FINDINGS

Of the 387 patients with ACL injury, 90 were reported to have ramp lesions (23.3%). The mean age at the time of diagnosis was 15.3 ​± ​0.81 years. The mean time from injury to MRI was 116.1 ​± ​113.5 days, while the mean time from injury to surgery was 172.6 ​± ​139.1 days. The MRI taken to detect ramp lesions in the paediatric population showed a pooled sensitivity of 50%, specificity of 75%, accuracy of 70%, PPV of 41% and NPV of 79%.

CONCLUSIONS AND RELEVANCE

The prevalence of ACL-associated ramp lesions in children and adolescents is similar to that in adult populations. Magnetic resonance imaging has low sensitivity but good specificity for assessing ramp lesions. In the presence of a posteromedial tibial bone bruise or a thin fluid signal separating the posterior horn of the medial meniscus and the posteromedial capsule a ramp lesion should always be suspected.

LEVEL OF EVIDENCE

Level IV.

STUDY REGISTRATION

PROSPERO -: CRD42023453895.

Chronic ACLD Knees with Early Developmental Cartilage Lesions Exhibited Increased Posterior Tibial Translation during Level Walking

OBJECTIVE

Early articular cartilage lesion (CL) is a vital sign in the onset of posttraumatic knee osteoarthritis (PTOA) in patients with anterior cruciate ligament deficiency (ACLD). Researchers have suggested that altered kinematics could accelerate CLs and, therefore, lead to the onset of PTOA. However, little is known about whether specific knee kinematics exist that lead to early CL in chronic ACLD knees. Level walking is the most frequent and relevant in vivo activity, which greatly impacts knee health. We hypothesized that the knee kinematics during level walking in chronic ACLD knees with early tibiofemoral CL would significantly differ from those of chronic ACLD knees without early tibiofemoral CL.

METHODS

Thirty patients with a chronic ACLD history, including 18 subjects with CLs and 12 subjects without CLs, and 35 healthy control subjects were recruited for the study from July 2020 to August 2022. The knee kinematic data during level walking were collected using a three-dimensional motion analysis system. The kinematic differences between groups were compared using statistical parametric mapping with one dimension for One-Way ANOVA. The cartilage statuses of the ACLD knees were assessed via MRI examination. The CLs distribution of subjects was evaluated using a modified Noyes scale and analyzed by chi-square tests.

RESULTS

ACLD knees with CLs had significantly greater posterior tibial translation (7.7-8.0mm, 12%-18% gait cycle GC, p = 0.014) compared to ACLD knees without CLs during level walking. ACLD knees with CLs had greater posterior tibial translation (4.6-5.5mm, 0%-23% GC, p < 0.001; 5.8-8.0mm, 86%-100% GC, p < 0.001) than healthy controls during level walking. In the group of ACLD knees with CLs, CL is mainly located in the back of the tibia plateau and front of load bearing area of the medial femoral condyle (p < 0.05).

CONCLUSION

Chronic anterior cruciate ligament deficient knees with cartilage lesions have increased posterior tibial translation compared to anterior cruciate ligament deficient knees without cartilage lesions and healthy subjects. The posterior tibial translation may play an important role in knee cartilage degeneration in ACLD knees. The increased posterior tibial translation and cartilage lesion characteristics may improve our understanding of the role of knee kinematics in cartilage degeneration and could be a helpful potential reference for anterior cruciate ligament deficient therapy, such as physical training to improve abnormal kinematic behavior.

Implementing injury prevention training in youth handball (I-PROTECT) in Sweden: study protocol for a cluster randomised trial

Introduction

Efficacy trials show that evidence-based injury prevention training reduces injuries in youth athletes but effectiveness, that is, outside the controlled setting, is lower and, consequently this training has had limited public health impact. Insufficient involvement of end-users at the individual and organisational levels is identified as a main barrier to successful implementation. The 'Implementing injury Prevention training ROutines in TEams and Clubs in youth Team handball (I-PROTECT)' uses an ecological participatory design incorporating the perspectives of multiple stakeholders throughout the project. Within the I-PROTECT research project, the specific aim of this study is to investigate the implementation of the end-user-targeted I-PROTECT programme.

Methods and analysis

This pragmatic two-armed cluster randomised controlled trial is conducted collaboratively with the Swedish Handball Federation that has overall responsibility for handball in Sweden. Randomly selected clubs in Sweden offering handball for both female and male youth players are invited to participate. 18 clubs are randomised (stratified by club size) to intervention (I-PROTECT plus tailored implementation support) or control (injury prevention programme currently available through the Swedish Handball Federation). The anticipated total number of potential participants (players, coaches, club administrators, parents/guardians) is ~3500. The I-PROTECT programme includes end-user-targeted information and physical and psychological injury prevention training available in a specifically developed interactive mobile application. Implementation strategies were selected from the Expert Recommendations for Implementing Change discrete implementation strategy compilation, based on feedback from end-users. Implementation outcomes will be investigated at the end of the handball season using the Reach, Effectiveness, Adoption, Implementation and Maintenance implementation evaluation framework. A study-specific questionnaire, app downloads and/or workshops will be used to collect data.

Ethics and dissemination

The Swedish Ethical Review Authority approved the study. Results will be disseminated in peer-reviewed scientific journals, as popular science articles, at international conferences and communicated via the Swedish Handball Federation.

Trial registration number

NCT05696119.

Repair of radial tears of the lateral meniscus on a stable knee: Results at a minimum follow-up of 2 years

INTRODUCTION

In younger patients, meniscal repair is recommended for isolated lateral meniscus tears that are most often due to acute trauma. But there is little published data on the outcomes of repairing this specific type of lesion. The goal of this study was to evaluate the clinical outcomes, report the failure rate of repairing radial tears of the lateral meniscus in stable knees and determine the risk factors for failure.

MATERIALS AND METHODS

All patients who had a stable knee and underwent arthroscopic repair of a radial lateral meniscus tear between April 2013 and December 2019 were reviewed retrospectively. Failure was defined as revision surgery for recurrence of symptoms (pain, locking) with intraoperative confirmation that the meniscus did not heal. The following data were collected: demographics (age, sex, BMI), time to surgery, clinical outcome scores (Tegner, Lysholm, IKDC), surgical details (repair technique, lesion zone, number of sutures).

RESULTS

Thirty patients were included having a mean age of 20.1years (14-31). The follow-up ranged from 24 to 110months (mean 66.8±25.2). An all-inside repair was done in 6 patients (20%); an outside-in technique was done in 17 patients (57%) and a combination of all-inside and outside-in was done in 7 patients (23%). Four patients (13%) had a recurrence of their symptoms later on, while participating in sports. All the recurrences were at the initial tear site. The time to revision surgery was 16, 19, 24 and 37months in these four patients (mean 24±9). All the other patients were able to resume sports at their pre-injury level. Significant improvement in the IKDC, Lysholm and Tegner functional scores were found between the preoperative and postoperative assessments. No statistically significant risk factors for failure were identified.

DISCUSSION

The functional healing rate after repair of a radial lateral meniscus tear in a stable knee was 86% at a mean follow-up of 5years, with the surgical technique having no impact on the long-term result. Most of the failures occurred within 2years of the repair procedure. We recommend repairing these tears as they have considerable healing potential.

LEVEL OF EVIDENCE

IV; retrospective observational cohort study.

Higher odds of meniscectomy compared with meniscus repair in a young patient population with increased neighbourhood disadvantage

OBJECTIVES

To investigate the impact of demographic and socioeconomic factors on the management of isolated meniscus tears in young patients and to identify trends in surgical management of meniscus tears based on surgeon volume.

METHODS

Data from a large healthcare system on patients aged 14-44 years who underwent isolated meniscus surgery between 2016 and 2022 were analysed. Patient demographics, socioeconomic factors and surgeon volume were recorded. Patient age was categorised as 14-29 years and 30-44 years old. Area Deprivation Index (ADI), a measure of neighbourhood disadvantage with increased ADI corresponding to more disadvantage, was grouped as <25th, 25-75th and >75th percentile. Multivariate comparisons were made between procedure groups while univariate comparisons were made between surgeon groups.

RESULTS

The study included 1552 patients treated by 84 orthopaedic surgeons. Older age and higher ADI were associated with higher odds of undergoing meniscectomy. Patients of older age and with non-private insurance were more likely to undergo treatment by a lower-volume knee surgeon. Apart from the year 2022, higher-volume knee surgeons performed significantly higher rates of meniscus repair compared with lower-volume knee surgeons. When controlling for surgeon volume, higher ADI remained a significant predictor of undergoing meniscectomy over meniscus repair.

CONCLUSION

Significant associations exist between patient factors and surgical choices for isolated meniscus tears in younger patients. Patients of older age and with increased neighbourhood disadvantage were more likely to undergo meniscectomy versus meniscus repair. While higher-volume knee surgeons favoured meniscus repair, a growing trend of meniscus repair rates was observed among lower-volume knee surgeons.

LEVEL OF EVIDENCE

Retrospective cohort study, level III.

Pathological progression of osteoarthritis: a perspective on subchondral bone

Osteoarthritis (OA) is a degenerative bone disease associated with aging. The rising global aging population has led to a surge in OA cases, thereby imposing a significant socioeconomic burden. Researchers have been keenly investigating the mechanisms underlying OA. Previous studies have suggested that the disease starts with synovial inflammation and hyperplasia, advancing toward cartilage degradation. Ultimately, subchondral-bone collapse, sclerosis, and osteophyte formation occur. This progression is deemed as "top to bottom." However, recent research is challenging this perspective by indicating that initial changes occur in subchondral bone, precipitating cartilage breakdown. In this review, we elucidate the epidemiology of OA and present an in-depth overview of the subchondral bone's physiological state, functions, and the varied pathological shifts during OA progression. We also introduce the role of multifunctional signal pathways (including osteoprotegerin (OPG)/receptor activator of nuclear factor-kappa B ligand (RANKL)/receptor activator of nuclear factor-kappa B (RANK), and chemokine (CXC motif) ligand 12 (CXCL12)/CXC motif chemokine receptor 4 (CXCR4)) in the pathology of subchondral bone and their role in the "bottom-up" progression of OA. Using vivid pattern maps and clinical images, this review highlights the crucial role of subchondral bone in driving OA progression, illuminating its interplay with the condition.

Injury Prevention Programmes Fail to Change Most Lower Limb Kinematics and Kinetics in Female Team Field and Court Sports: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

BACKGROUND

One mechanism by which exercise interventions may be effective in reducing anterior cruciate ligament (ACL) injury risk is through changes in lower limb biomechanics. Understanding how training programmes affect lower-limb kinematics and kinetics may help refine injury prevention programmes.

OBJECTIVE

The aim of this systematic review and meta-analysis was to assess the effect of injury prevention programmes on kinematics and kinetics during tasks related to ACL injury in female team field and court sports.

DATA SOURCES

Five databases were searched in October 2022.

ELIGIBILITY CRITERIA

Randomised controlled trials assessing the effect of injury prevention programmes compared with usual training/no training on lower limb kinematics and kinetics in female team field and court sports were eligible for review.

RESULTS

Sixteen studies were included. A total of 976 female athletes were included. Most of the studies included interventions with multiple components (12/16). Commonly used components were plyometrics (12/16), strength (8/16), and balance/stability (7/16). Thirteen studies had routine training or sham interventions as the control group and three studies had no training. Very low certainty evidence suggests that injury prevention programmes increase knee flexion angles (mean difference = 3.1° [95% confidence interval 0.8-5.5]); however, very low to low certainty evidence suggests no effect on hip flexion angles/moments, knee flexion moments, hip adduction angles/moments, knee adduction angles/moments, hip internal rotation angles/moments, ankle dorsiflexion angles, and ground reaction forces, compared with usual training/no training.

CONCLUSION

Injury prevention programmes may be effective in increasing knee flexion angles during dynamic landing and cutting tasks but may have no effect on other lower limb biomechanical variables. As such, the benefits of injury prevention programmes may be mediated by factors other than altered biomechanics and/or may happen through other biomechanical measures not included in this review.

30 years with the Knee injury and Osteoarthritis Outcome Score (KOOS)

This narrative review describes the development and use of patient-reported outcomes over 30 years, focusing on the Knee injury and Osteoarthritis Outcome Score (KOOS). KOOS is a five-subscale patient-reported instrument intended for use from the time of knee injury to the development of osteoarthritis. Numerous studies have confirmed that the psychometric properties of the KOOS and its short-form KOOS-12 are acceptable. More recent research has focused on the use and interpretation of KOOS scores in clinical trials using thresholds, such as minimal important differences, patient-acceptable symptom states, and treatment failure. As an indication of KOOS's popularity, the total 3854 PubMed results for KOOS have increased exponentially since the first KOOS paper was published 25 years ago and now seem to have plateaued at around 650 annually. The selected articles are not based on a systematic search, but on the author's own publications, reading, and literature search that grew organically from that.

Unanticipated mid-flight external trunk perturbation increased frontal plane ACL loading variables during sidestep cuttings

Unanticipated trunk perturbation is commonly observed when anterior cruciate ligament (ACL) injuries occur during direction-changing manoeuvres. This study aimed to quantify the effect of mid-flight medial-lateral external trunk perturbation directions/locations on ACL loading variables during sidestep cuttings. Thirty-two recreational athletes performed sidestep cuttings under combinations of three perturbation directions (no-perturbation, ipsilateral-perturbation, and contralateral-perturbation relative to the cutting leg) and two perturbation locations (upper-trunk versus lower-trunk). The pushing perturbation was created by customised devices releasing a slam ball to contact participants near maximum jump height prior to cutting. Perturbation generally resulted in greater peak vertical ground reaction force and slower cutting velocity. Upper-trunk contralateral perturbation showed the greatest lateral trunk bending away from the travel direction, greatest peak knee flexion and abduction angles, and greatest peak internal knee adduction moments compared to other conditions. Such increased ACL loading variables were likely due to the increased lateral trunk bending and whole-body horizontal velocity away from the cutting direction caused by the contralateral perturbation act at the upper trunk. The findings may help understand the mechanisms of indirect contact ACL injuries and develop effective cutting techniques for ACL injury prevention.

Development of radiographic knee osteoarthritis and the associations to radiographic changes and baseline variables in individuals with knee pain: a 2-year longitudinal study

OBJECTIVES

The aim was to study the development of radiographic knee osteoarthritis (RKOA) in individuals with knee pain over 2 years, and the associations between radiographic changes and baseline variables.

DESIGN

Longitudinal cohort study.

PARTICIPANTS AND SETTING

This study is part of the Halland Osteoarthritis cohort. The included 178 individuals, aged 30-67, had knee pain, without cruciate ligament injury or radiographic findings and 67% were women. The presence of RKOA was defined as Ahlbäck score of ≥1 in ≥1 knee. (Ahlbäck grade 1: joint space narrowing in the tibiofemoral joint <3 mm). Diagnosis of clinical KOA was based on the clinical guideline from the National Institute for Health and Care Excellence (NICE). Knee injury and Osteoarthritis Outcome Score (KOOS), pain intensity, physical function, body mass index (BMI) and visceral fat area (VFA) were measured. Associations to RKOA were analysed with logistic regression (OR).

RESULTS

In all, 13.8% (n=24) developed RKOA in 2 years whereof all had clinical KOA at baseline, as defined by NICE. Deterioration to RKOA was significantly associated with higher BMI, OR 1.119 (95% CI 1.024 to 1.223; p=0.013), and VFA, 1.008 (95% CI 1.000 to 1.016; p=0.049), worse knee pain intensity, 1.238 (95% CI 1.028 to 1.490; p=0.024), worse scores for KOOS Pain, 0.964 (95% CI 0.937 to 0.992; p=0.013) and KOOS Symptoms, 0.967 (95% CI 0.939 to 0.996; p=0.027), KOOS Activities of daily living 0.965 (95% CI 0.935 to 0.996; p=0.026) and KOOS Quality of Life 0.973 (95% CI 0.947 to 0.999; p=0.044), at baseline.

CONCLUSIONS

One out of seven individuals with clinical KOA developed RKOA in only 2 years. Baseline variables associated with RKOA after 2 years may possibly be detected early by using the NICE guideline, assessment of obesity and self-reported data of symptoms to support first-line treatment: education, exercise and weight control.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov (NCT04928170).

Cross-Sectional and Longitudinal Associations of Comorbidities with Knee Symptoms and Radiographic Abnormalities of Osteoarthritis

INTRODUCTION

This study aimed to investigate the associations of comorbidities with knee symptoms and radiographic abnormalities of osteoarthritis (OA).

METHODS

Participants were from the Osteoarthritis Initiative. Comorbidities were identified at baseline using the modified Charlson Comorbidity Index. For both knees, symptoms were assessed annually from baseline to 48 months using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores (rescaled range 0-100), and radiographic abnormalities using the Kellgren-Lawrence (KL, 0-4) grades. The presence of significant pain and functional disability was defined as a WOMAC score of ≥ 25 and ≥ 22, respectively, and radiographic OA (ROA) as KL ≥ 2. An increase of ≥ 9 in WOMAC scores and ≥ 1 in KL grades were defined as symptomatic and radiographic progression, respectively.

RESULTS

Of 3337 participants, 28% and 9% had one and ≥ 2 comorbidities, respectively. The number of comorbidities was associated with the presence of significant functional disability (odds ratios [ORs] 1.15; 1.46) and predicted the progression of both knee pain and functional disability (ORs 1.11; 1.51). For the type of comorbidities, non-OA musculoskeletal diseases were associated with the presence of ROA and significant functional disability (ORs 1.63; 1.82) and showed a trend to predict incident ROA (OR 1.84, 95% confidence interval 1.00-3.38 p = 0.051). Diabetes and kidney diseases were associated with symptomatic progression of OA (ORs 1.38; 2.72).

CONCLUSIONS

Having more comorbidities, especially diabetes and kidney diseases, is associated with symptomatic progression of knee OA. Moreover, non-OA musculoskeletal diseases may be associated with the presence and onset of ROA.

Falling decreased anterior cruciate ligament loading variables during single-leg landings after mid-flight external trunk perturbation

Mid-flight external upper-trunk perturbation is associated with increased anterior cruciate ligament (ACL) injury risk during landing. This study aimed to assess the effect of natural, soft, and falling landing techniques on knee mechanics and vertical ground reaction forces (VGRF) during single-leg landings with/without mid-flight medial-lateral external upper-trunk pushing perturbation. Twenty-eight participants performed single-leg landings using the three landing techniques with/without mid-flight pushing perturbation. The perturbation was created by a customized apparatus releasing a slam ball and pushing the participants near the peak jump height at the upper trunk. Perturbation resulted in significantly greater lateral trunk bending angles, knee flexion angles at initial contact, peak knee abduction angles, and peak knee adduction moments compared to no perturbation. The falling condition significantly demonstrated the greatest lateral trunk bending angles, knee flexion angles, and peak knee external rotation moments and the smallest peak knee abduction angles, peak VGRF, and peak knee extension moments compared to natural/soft landings regardless of perturbation conditions. Mid-flight external perturbation resulted in variables associated with greater ACL loading during single-leg landings. Falling demonstrated variables associated with smaller ACL loading, particularly for perturbation conditions. Incorporating falling techniques into jump-landing training programs may guide players to safely fall on the ground when perturbation occurs. Falling provides an alternative strategy to potentially decrease indirect contact ACL injury risk when the sports environment allows.

Previous cartilage surgery is associated with inferior patient-reported outcomes after knee arthroplasty

PURPOSE

The hypothesis of the present study assumed that a history of focal cartilage lesions would not affect Knee Injury and Osteoarthritis Outcome scores (KOOSs) following knee arthroplasty compared to a matched national cohort of knee arthroplasty patients.

METHODS

Fifty-eight knee arthroplasty patients with previous surgery for focal cartilage lesions (cartilage cohort) were compared to a matched cohort of 116 knee arthroplasty patients from the Norwegian Arthroplasty Register (control group). Age, sex, primary or revision arthroplasty, type of arthroplasty (total, unicondylar or patellofemoral), year of arthroplasty surgery and arthroplasty brand were used as matching criteria. Demographic data and KOOS were obtained through questionnaires. Regression models were employed to adjust for confounding factors.

RESULTS

Mean follow-up post knee arthroplasty surgery was 7.6 years (range 1.2-20.3) in the cartilage cohort and 8.1 (range 1.0-20.9) in the control group. The responding patients were at the time of surgery 54.3 versus 59.0 years in the cartilage and control group, respectively. At follow-up the control group demonstrated higher adjusted Knee Injury and Osteoarthritis Outcome subscores than the previous focal cartilage patients with a mean adjusted difference (95% confidence interval in parentheses): Symptoms 8.4 (0.3, 16.4), Pain 11.8 (2.2, 21.4), Activities of daily living (ADL) 9.3 (-1.2, 18.6), Sport and recreation 8.9 (-1.6, 19.4) and Quality of Life (QoL) 10.6 (0.2, 21.1). The control group also demonstrated higher odds of reaching the patient-acceptable symptom state threshold for the Knee Injury and Osteoarthritis Outcome subscores with odds ratio: Symptoms 2.7 (1.2, 6.4), Pain 3.0 (1.3, 7.0), ADL 2.1 (0.9, 4.6) and QoL 2.4 (1.0, 5.5).

CONCLUSION

Previous cartilage surgery was associated with inferior patient-reported outcomes after knee arthroplasty. These patients also exhibited significantly lower odds of reaching the patient-acceptable symptom state threshold for the Knee Injury and Osteoarthritis Outcome subscores.

LEVEL OF EVIDENCE

Level III.

Comparison of immediate versus optional delayed surgical repair for treatment of acute anterior cruciate ligament injury through a parallel, multicentric, pragmatic randomized controlled trial - IODA trial

BACKGROUND

Standard care for anterior cruciate ligament (ACL) injuries often includes surgical reconstruction of the ACL. However, two randomized controlled trials [1, 2] (RCT) concluded that conservative treatment does not result in inferior clinical outcomes compared to immediate ACL reconstruction. More research is needed to verify these results and assess whether patient-specific parameters determine if a patient would benefit from one treatment option over the other.

METHODS

This is a pragmatic, multi-center RCT with two parallel groups. Patients with an acute ACL injury will be recruited from Belgian hospitals. Patients will be randomized to conservative treatment (rehabilitation + optional delayed surgery) or immediate ACL reconstruction (< 12 weeks). The primary outcome is the Knee injury and Osteoarthritis Outcome Score (KOOS) at 7 months (short term) and 1-year long term) post-injury. These following additional outcomes will be administered at 4 and 7 months (short term) and 1, 2, and 3 years post-injury (long term): patient-reported outcomes concerning knee symptoms, knee function and quality of life, functional knee tests, time to return to pre-injury activity level and return to work, structural knee joint damage and cartilage health (only at 4 months and 3 years post-injury), as well as adverse events such as re-rupture rates. Furthermore, the secondary objective is to identify (through a predictive analysis) individuals who would benefit the most from early reconstruction versus those who should rather be treated conservatively.

DISCUSSION

This large RCT will assess the clinical effectiveness of both surgical and conservative treatment. In addition, it will be the first study that provides insights into which patient-specific factors predict successful outcomes after conservative treatment of ACL injuries. These results will be the first step toward early patient identification regarding treatment decisions. This is urgently needed to avoid (1) delayed surgeries and prolonged rehabilitation and (2) unnecessary surgeries.

TRIAL REGISTRATION

this trial was registered on ClinicalTrials.gov (NCT05747079) on 10/02/2023.