Higher Unilateral Muscle Imbalance at the Contralateral Knee 6 Months after Anterior Cruciate Ligament Reconstruction.

There are a considerable number of patients who, after anterior cruciate ligament reconstruction (ACL), suffer from relapses or reduced performance. Data collected from isokinetic dynamometry can provide useful information on the condition of the knee during rehabilitation. Seventy-one young sports patients with ACL reconstruction performed concentric (CON) isokinetic dynamometry (CON/CON 90°/s and CON/CON 240°/s) to assess the muscle strength of the quadriceps (Q) and hamstrings (H) in both knees at 6 months after ACL reconstruction. Limb symmetry index (LSI) and the H/Q ratio were calculated. Comparative statistical tests and multivariate regression were performed. At 90°/s, 57 patients (80.3%) had an LSI below 90% for quadriceps and 28 (60.6%) for hamstring. The number of imbalanced patients according to H/Q ratio was higher in the non-operated knee (n = 56, 78.9%) (p < 0.001). At 240°/s, 49 cases (69.1%) had LSI values above 90% for quadriceps and 37 (52.1%) for hamstrings. Regarding H/Q, imbalanced cases were higher in the non-operated limb (n = 60, 84.5%) (p < 0.001). Strength data at 6 months after ACL reconstruction and post-operative rehabilitation indicated greater unilateral (H/Q) muscle imbalance in the non-operated knee than in the operated knee. Most patients did not achieve the adequate LSI values.

Combination of the medial patellofemoral ligament reconstruction with the quasi-anatomic technique, tibial tuberosity osteotomy, lateral retinaculum release and mosaicplasty produces satisfactory results for patients with patello-femoral instability. 2-Year follow-up.

INTRODUCTION: This study aimed to evaluate the effectiveness and safety of a combined surgical approach for treating complex patellofemoral instability. This approach combines four procedures: medial patellofemoral ligament (MPFL) reconstruction with the quasi-anatomic technique, lateral retinaculum release, anteromedialization and distalization of tibial tuberosity and patellar/femoral mosaicplasty. MATERIAL AND METHODS: Between August and November 2021, we enrolled 27 patients in the study (21 females, 6 males, average age 28.6 years). All with patella alta, recurrent patellar instability, severe cartilage focal damage, and increased tibial tubercle-trochlear groove distance. All underwent the combined procedure during this period. We assessed their pain and functional scores before surgery and at 6, 12, and 24 months after surgery using standardized scoring systems. RESULTS: Patients initially reported significant pain and functional limitations. However, at 24 months, their pain scores significantly reduced, averaging 1.5 compared to 8.2 pre-surgery. Similarly, their functional scores substantially improved, with Lysholm, Tegner, Kujala, BPII scores reaching 87.44, 8.44, 90.03, 86.07 compared to 56.4, 3.7, 42.48, 23 pre-surgery, respectively. Importantly, no cases of recurrent instability occurred, and 96.3% of patients reported complete satisfaction. CONCLUSIONS: This combined surgical approach has a high rate of success for patients with patella alta, recurrent lateral patellar instability, severe focal chondral lesions, and increased TT-TG distance. Moreover, 26 out of 27 patients (96.3%) reported total satisfaction. Therefore, we conclude that although this procedure combination is not simple, it is a safe, reproducible, and alleviates pain at 24 months postoperatively, and significantly improves functional scores.

Effectiveness of Photobiomodulation in Reducing Pain and Disability in Patients With Knee Osteoarthritis: A Systematic Review With Meta-Analysis.

OBJECTIVE: Photobiomodulation (PBM) is not implemented in routine clinical management for knee osteoarthritis. This study aims to systematically investigate the effects of PBM in patients with knee osteoarthritis, comparing with placebo to understand its true clinical effects. METHODS: PubMed, EMBASE, Web of Science, and Cochrane databases were searched up to October 2023. Randomized placebo-controlled trials applying PBM versus placebo were included. Study characteristics, intervention parameters, and patient-reported and physical examination outcome measures were collected. The risk of bias was judged using the Cochrane risk-of-bias tool for randomized trials (version 2) and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) to interpret the certainty of results. RESULTS: Ten studies were included comprising 542 participants. All studies were judged with unclear to a high risk of bias. Meta-analysis for pain at rest (6 studies) showed that PBM significantly reduced pain at rest as compared to placebo (-0.7 [95% CI = -1.1 to -0.2]), moderate effect, very low certainty of evidence, whereas for the Timed "Up & Go" Test (three studies), no significant effect was detected. Statistically significantly within-group (PBM) mean improvement was detected for pain, Lequesne Index, and gait performance outcomes, but not always clinically relevant or significant when compared to placebo. CONCLUSION: PBM reduces pain intensity in patients with knee osteoarthritis and may improve disability. However, the very low certainty of evidence does not allow to recommend its isolated use but may be used to complement other widely recommended therapies. More rigorous clinical trials and the revision of the recommended dosage guidelines are warranted to increase the strength of evidence. IMPACT: The findings indicate that photobiomodulation can reduce pain and improve disability in patients with knee osteoarthritis. However, researchers should continue to investigate isolated photobiomodulation intervention versus placebo and extend the dosage guidelines to other types of light emitters.

Beyond the patella: Treatment of cam femoroacetabular impingement syndrome improves anterior knee pain.

OBJECTIVES: This study aimed to investigate if there is a relationship between cam femoroacetabular impingement syndrome (cam-FAIS) and chronic anterior knee pain (AKP). METHODS: This is a pilot retrospective review of 12 AKP patients with no structural anomalies in the patellofemoral joint and no skeletal malalignment in the lower limbs. All the patients were resistant to proper conservative treatment for AKP (AKP-R). Subsequently, these patients developed pain in the ipsilateral hip several months later, and upon evaluation, were diagnosed with cam-FAIS. Arthroscopic femoral osteoplasty and labral repair were performed and clinical follow-up of hip and knee pain and function (Kujala Score and Non-arthritic Hip Score -NAHS-) was carried out. RESULTS: All the patients showed improvement in the knee and hip pain scores with a statistically significant clinical difference in all of them at 69 months follow up (range: 18 to 115) except one patient without improvement in the groin VAS score post-operatively. Visual analogical scale (VAS) of knee pain improved from 6.3 (range: 5 to 8) to a postoperative 0.5 (range: 0 to 3.5), (p â€‹< â€‹0.001). The VAS of groin pain improved from 4.4 (range: 2 to 8) to a postoperative 0.9 (range: 0 to 3), (p â€‹< â€‹0.001). NAHS improved from a preoperative 67.9 (range: 28.7 to 100) to a postoperative 88 (range: 70 to 100), (p â€‹< â€‹0.015) and knee Kujala's score improved from a preoperative 48.7 (range: 22 to 71) to a postoperative 96 (range: 91 to 100), (p â€‹< â€‹0.001). CONCLUSION: This study's principal finding suggests an association between cam-FAIS and AKP-R in young patients who exhibit normal knee imaging and lower limbs skeletal alignment. Addressing cam-FAIS in these cases leads to resolution of both groin and knee pain, resulting in improved functional outcomes for both joints. STUDY DESIGN: Retrospective cohort series with a single contemporaneous long-term follow-up. LEVEL OF EVIDENCE: IV.

Derotational high tibial osteotomy in cases of anterior knee pain and/or patellofemoral instability: a systematic review.

IMPORTANCE: Derotational high tibial osteotomy (HTO) is a surgical intervention for correcting rotational malalignments in the lower limb, which may contribute to anterior knee pain (AKP) and/or patellofemoral instability (PFI). This surgical technique is not yet widely implemented and requires a systematic evaluation of its outcomes. AIM: To assess the effectiveness of derotational HTO in correcting rotational malalignments of the lower limb in patients with AKP and/or PFI through radiological, clinical, and patient-reported outcome measures. EVIDENCE REVIEW: Searches were conducted in the PubMed, Embase, and Web of Science databases up to March 3, 2023, to identify studies utilizing derotational HTO in patients with AKP and/or PFI. The primary outcome measures of interest were measurements of lower limb angular correction. Other radiological, clinical, and patient-reported outcome measures were also analyzed. The risk of bias was judged with the RoBANS tool. FINDINGS: A total of 8 studies were included, comprising 215 patients (27.0 â€‹± â€‹3.9 years) and 245 knees. The most reported angle was tibial torsion (k â€‹= â€‹6 studies, n â€‹= â€‹173 knees), with a mean difference between postoperative and preoperative values (postsurgical correction) ranging from -37.8° to -10.8°. Patient-reported outcome measures showed significant improvements in the postoperative moment, exceeding the minimal clinically important difference in almost all cases, and with high patient satisfaction (93.6%). CONCLUSIONS AND RELEVANCE: Derotational HTO allows the correction of rotational malalignments of the lower limb (tibial torsion) and promotes patient satisfaction. LEVEL OF EVIDENCE: Level IV.

Anterior knee pain patients without structural knee abnormalities and normal lower limb skeletal alignment have a higher prevalence of cam-femoroacetabular impingement syndrome than the general population.

OBJECTIVES: This study aimed to ascertain the prevalence of cam femoroacetabular impingement syndrome (cam-FAIS) in anterior knee pain (AKP) patients devoid of both structural patellofemoral joint abnormalities and lower limb skeletal malalignment. A secondary objective was to examine pain and disability differences between AKP patients with and without cam-FAIS. METHODS: A total of 209 AKP patients were screened for eligibility. Inclusion criteria were normal imaging studies and normal lower limb alignment, and exclusion criteria were previous knee surgery and knee and/or hip osteoarthritis. Of those, 49 (23.4%) were eligible and this number matched a previous power analysis to detect statistically significant differences in prevalence of cam-FAIS in a population of AKP patients. The first step in the study sequence was to ask the patient whether they had groin pain. If so, the impingement test was done. Then, the femoral cam morphology defined by an alpha angle greater than or equal to 55° in a 45° Dunn axial view of the hip was ruled out. Additionally, patients completed Kujala and International Knee Documentation Committee (IKDC) functional knee scores for disability assessment. General population control group was obtained from literature. RESULTS: The study included 9 males and 40 females, with an average age of 36 (20-50, ±SD 8.03) years. Groin pain and positive impingement test were found in 26/49 patients (53%). An alpha angle ≥55° was observed in 35/49 patients (71%). A combination of groin pain, positive impingement test and an alpha angle ≥55° was seen in 18/49 patients (37%). The AKP patients with groin pain, a positive impingement test and an alpha angle ≥55° exhibited statistically similar pain and disability levels as AKP patients without cam-FAIS. CONCLUSION: The results of this study suggest that AKP patients without structural abnormalities in the patellofemoral joint and without lower limbs malalignment have a statistically significantly higher prevalence of cam-FAIS than the general population. Moreover, AKP patients with cam-FAIS have a statistically similar degree of pain and disability than AKP patients without it. STUDY DESIGN: Cross-sectional study. LEVEL OF EVIDENCE: IV.

Women show a positive response to platelet-rich plasma despite presenting more painful knee osteoarthritis than men.

PURPOSE: The purpose of this study was to evaluate the impact of gender on the efficacy of platelet-rich plasma (PRP) in patients with knee osteoarthritis (KOA), comparing their short-term response between men and women. METHODS: Four hundred-eighteen patients (529 knees) were included. Patients were treated with three injections of PRP on a weekly basis. Blood and PRP samples were randomly tested. Patients were asked to complete the knee injury and osteoarthritis outcome score (KOOS) and 12-item short form survey (SF-12), at baseline and 6 months. Success rates were calculated according to a reduction in the pain score of at least 9.3 points [minimal clinically important improvement (MCII)]. Comparative tests and multivariate regression were performed. RESULTS: The PRP had a platelet concentration factor of 2.0X compared to blood levels, with no leucocytes or erythrocytes. KOOS scores showed an increase from baseline to 6 months (p < 0.0001). There was an increase in the physical component summary (PCS) (p < 0.0001) and mental component summary (MCS) (p < 0.01) of the SF-12. The number of knees of women with MCII was 156 out of 262 (59.6%), whereas the number of knees of men was 136 out of 267 (50.9%) (p = 0.0468). Women had worse baseline scores on pain (p = 0.009), PCS (p < 0.0001) and MCS (p < 0.0001). CONCLUSION: Although the symptomatology generated by KOA was worse in women when compared to men, treatment with repeated injections of PRP was effective, ultimately achieving a higher improvement in women providing comparable final follow-up outcomes between men and women. LEVEL OF EVIDENCE: Level IV.

Derotational distal femoral osteotomy corrects excessive femoral anteversion in patients with patellofemoral instability: A systematic review.

PURPOSE: Patellofemoral instability (PFI) is a common condition that can be caused from multiple factors, including lower limb rotational malalignments. Determining precise criteria for performing corrective torsional osteotomy can be a daunting task due to the lack of consensus on normal and excessive values and the limited evidence-based data in the postoperative results. The purpose was to assess the clinical, functional and imaging outcomes following derotational distal femoral osteotomy (DDFO) in patients with PFI and/or anterior knee pain (AKP) associated with lower limb rotational malalignments. METHODS: Searches were conducted on PubMed, EMBASE and Web of Science databases up to October 2023. Studies reporting outcomes after DDFO in patients with PFI and/or AKP were eligible for the systematic review. The primary outcome was imaging metrics, especially femoral anteversion. Secondary outcomes included the patient-reported outcome measures (PROMs) (clinical and functional). Quantitative synthesis involved the use of weighted averages to calculate pre- to postoperative mean differences (MD) and compare them against the minimal clinically important difference (MCID). RESULTS: Ten studies (309 knees) were included with a mean follow-up of 36.1 ± 11.7 months. Imaging outcomes consistently indicated the correction of femoral anteversion (MD = -19.4 degrees, 95% confidence interval: -20.1 to -18.7) following DDFO. PROMs showed significant improvements in most studies, exceeding the MCID. Patient satisfaction with the DDFO was high (93.3%). CONCLUSIONS: The DDFO was an effective treatment option for correcting excessive femoral anteversion in patients with PFI associated with clinically relevant functional and clinical improvement and a high satisfaction rate. LEVEL OF EVIDENCE: Level IV, systematic review of level II-IV studies.

Mid-Term Clinical and Radiological Outcomes of Lateral Meniscal Allograft Transplantation with Suture-Only Fixation Plus Capsulodesis.

Meniscal allograft transplantation (MAT) is an effective reconstructive procedure for treating a symptomatic postmeniscectomy syndrome. It consists of replacing the lost meniscal tissue aiming to improve the clinical outcomes and prevent progressive deterioration of the joint. The aim of this study was to evaluate meniscal graft survivorship and report on the radiographic (in terms of graft extrusion and joint space width and alignment) and the functional results through a midterm follow-up of lateral MAT performed with a soft tissue fixation technique after capsulodesis. In total, 23 patients who underwent lateral MAT as a single procedure were included. The Knee injury and Osteoarthritis Outcome Score, Lysholm, Tegner, and visual analog scale scales were used for patient assessment. Magnetic resonance imaging and a complete radiographic protocol were conducted to determine the degree of meniscal extrusion and the changes in the degree of osteoarthritis and coronal alignment. Assessments were performed after 2 and 7 years of follow-up. A significant improvement in all the scores, relative to preoperative values, was found after 7 years of follow-up. This improvement remained consistent throughout the first and second follow-up periods. A mean absolute extrusion of 2.2 mm ± 1.6 and an extrusion percentage of 28.0% ± 11.43 were found, with no significant differences throughout the follow-up periods. There was no statistically significant difference in terms of the frontal mechanical axis and joint space narrowing between the preoperative value and at the first and second follow-up periods. A survival rate of 85.7% was found after 7 years of follow-up. Capsulodesis results in a low degree of meniscal extrusion in isolated lateral MAT fixed with a suture-only technique, which is maintained after 7 years of follow-up, with a high graft survival index (>85%) and satisfactory results on the functional scales.

A modified Delphi consensus statement on patellar instability: part I.

Aims: The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach. Methods: A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous. Results: Of 27 questions and statements on patellar instability, three achieved unanimous consensus, 14 achieved strong consensus, five achieved consensus, and five did not achieve consensus. Conclusion: The statements that reached unanimous consensus were that an assessment of physeal status is critical for paediatric patients with patellar instability. There was also unanimous consensus on early mobilization and resistance training following nonoperative management once there is no apprehension. The statements that did not achieve consensus were on the importance of immobilization of the knee, the use of orthobiologics in nonoperative management, the indications for MPFC repair, and whether a vastus medialis oblique advancement should be performed.

A modified Delphi consensus statement on patellar instability: part II.

Aims: The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process. Methods: This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous. Results: Of 41 questions and statements on patellar instability, none achieved unanimous consensus, 19 achieved strong consensus, 15 achieved consensus, and seven did not achieve consensus. Conclusion: Most statements reached some degree of consensus, without any achieving unanimous consensus. There was no consensus on the use of anchors in MPFL reconstruction, and the order of fixation of the graft (patella first versus femur first). There was also no consensus on the indications for trochleoplasty or its effect on the viability of the cartilage after elevation of the osteochondral flap. There was also no consensus on postoperative immobilization or weightbearing, or whether paediatric patients should avoid an early return to sport.

Meniscal extrusion in knees with and without osteoarticular pathology: A systematic review of normative values and cut-offs for diagnostic criteria.

BACKGROUND: Meniscus extrusion is crucial for the diagnosis and treatment of meniscal injury, but the literature on this topic has not yet been systematized. The purpose of this systematic review was to compare diagnostic methods and summarize the data of medial and lateral meniscal extrusion in knees with and without osteoarticular pathology. METHODS: This systematic review was conducted according to the PRISMA 2020 statement. Searches were conducted on PubMed, EMBASE and Cochrane databases to identify studies that measured meniscal extrusion using magnetic resonance imaging (MRI) or ultrasound (US). Meniscal extrusion data was summarized as weighted mean for medial and lateral meniscus, and stratified according to the method of measurement (MRI or US) and presence of knee osteoarticular pathology. RESULTS: A total of 26 studies were included in this review. Weighted mean values of meniscal extrusion were always higher for the medial than the lateral meniscus, regardless of the method of measurement. The medial meniscus extrusion was always higher in knees with osteoarticular pathology than those without. For the lateral meniscus extrusion, the mean values were higher in those knees without osteoarticular pathology. When classifying pathological meniscal extrusion with pre-defined cut-off values, the higher the cut-off used, the lower the percentage of knees classified as pathological meniscal extrusion. CONCLUSIONS: The medial meniscus presents on mean higher extrusion and extrusion is higher in knees with osteoarticular pathology. Based on summary data, the most suitable cut-offs for pathological meniscal extrusion for both MRI and US seem to fall within >2 and >3 mm.

The Role of Systemic Steroids in Sciatica Due to Herniated Lumbar Disc: A Systematic Review and Meta-analysis.

STUDY DESIGN: Systematic review and meta-analysis. OBJECTIVE: Evaluate the role of systemic steroids in treating patients with sciatica due to lumbar disk herniation (LDH). SUMMARY OF BACKGROUND DATA: The association between LDH and sciatica has been well described. The use of steroids seems logical in this context; however, their efficacy is not well described, and their use remains controversial. METHODS: A comprehensive search on PubMed, EMBASE, and Scopus databases (up to February 15, 2022) was performed to identify randomized clinical trials that included patients with symptoms of sciatica due to LDH that were treated with systemic steroids. The risk of bias was judged using the Cochrane risk-of-Bias2 tool. Meta-analysis was conducted using a random-effects model to estimate the between-group effect size for pain and functional outcomes. The risk of developing adverse events (AE) was computed using relative risks. All pooled results are reported with their 95% confidence interval (CI) and certainty of evidence analyzed using the Grading of Recommendations Assessment, Development, and Evaluation framework. RESULTS: Ten studies met inclusion criteria, comprising a total of 1017 participants: 540 in the treatment group and 477 in the control group. Steroid treatment was associated with a significant superior reduction of pain (SMD = -0.42, 95% CI -0.76 to -0.08, weak effect, very-low certainty) and reduction in disability (SMD = -0.30, 95% CI -0.51 to -0.10, weak effect, very-low certainty). Corticosteroid administration was associated with a significant increased risk of developing an AE (relative risks = 2.00, 95% CI 1.40 to 2.85, low certainty). CONCLUSION: The use of systemic steroids in the treatment of sciatica due to LDH seems reasonable despite a 2-fold higher risk of developing mild AEs. However, the effect size is small for reducing pain in the short term and improving functional outcomes at long-term follow-up.

Inconsistency in Shoulder Arthrometers for Measuring Glenohumeral Joint Laxity: A Systematic Review.

There is no consensus on how to measure shoulder joint laxity and results reported in the literature are not well systematized for the available shoulder arthrometer devices. This systematic review aims to summarize the results of currently available shoulder arthrometers for measuring glenohumeral laxity in individuals with healthy or injured shoulders. Searches were conducted on the PubMed, EMBASE, and Web of Science databases to identify studies that measure glenohumeral laxity with arthrometer-assisted assessment. The mean and standard deviations of the laxity measurement from each study were compared based on the type of population and arthrometer used. Data were organized according to the testing characteristics. A total of 23 studies were included and comprised 1162 shoulders. Populations were divided into 401 healthy individuals, 278 athletes with asymptomatic shoulder, and 134 individuals with symptomatic shoulder. Sensors were the most used method for measuring glenohumeral laxity and stiffness. Most arthrometers applied an external force to the humeral head or superior humerus by a manual-assisted mechanism. Glenohumeral laxity and stiffness were mostly assessed in the sagittal plane. There is substantial heterogeneity in glenohumeral laxity values that is mostly related to the arthrometer used and the testing conditions. This variability can lead to inconsistent results and influence the diagnosis and treatment decision-making.

High survival rate after the combination of intrameniscal and intraarticular infiltrations of platelet-rich plasma as conservative treatment for meniscal lesions.

PURPOSE: To evaluate the efficacy of applying a combination of intrameniscal and intraarticular infiltrations of Platelet-Rich Plasma (PRP) in patients with meniscal tears, analyzing its failure rate and clinical evolution, as well as factors that may influence the positive response to this treatment. METHODS: Three hundred and ninety-two cases out of 696 met the inclusion criteria and were included in this work. Survival and patient-reported outcome measure (PROM) were collected and analyzed. Survival rate was defined as the percentage of patients who did not undergo meniscus surgery during their follow-up time. Patients were asked to complete the Knee injury and Osteoarthritis Outcome Score (KOOS) at baseline, 6 months and 18 months. Other patient- and pathology-related variables were collected. Blood and PRP samples were randomly tested as a quality control measure. Survival and comparative statistical tests, and multivariate regression were performed for the analysis of the variables. RESULTS: The PRP applied had a platelet concentration factor of 1.9X in respect to blood levels, with no leukocytes or erythrocytes. Thirty-eight patients required surgical intervention after treatment reaching a survival rate of 90.3% with an estimated mean survival time of 54.4 months. The type of injury (P = 0.002) and the presence of chondropathy were risk factors for surgical intervention after PRP treatment (P = 0.043). All KOOS scores showed a significant statistical increase from baseline to 6 months (N = 93) and 18 months (N = 66) (P < 0.0001). The number of cases with minimal clinically important improvement (MCII) at 6 months and 18 months post-treatment was 65 (69.9%) and 43 (65.2%), respectively. CONCLUSION: The combination of intrameniscal and intraarticular PRP infiltrations is a valid conservative treatment for meniscal injuries avoiding the need for surgical intervention. Its efficacy is higher in horizontal tears and decreases when joint degeneration is present. LEVEL OF EVIDENCE: Level IV.

The effect of short-term cryopreservation on the properties and functionality of platelet-rich plasma.

Platelet Rich Plasma (PRP) is a biological treatment which, thanks to its enhanced growth factors content, is widely used in the field of regenerative medicine for its reparative effects. Although it is usually used fresh immediately after preparation, its freezing for preservation for future usage could be key in increasing its versatility and new applications. To assess the suitability of freezing, after collecting PRP and platelet lysates (PL) from 6 patients, they were preserved for 1 or 3 months at temperatures of -20ºC and -80°C. Measurements were then made on platelet number and integrity, growth factor levels, biomechanical properties of the clot and its bioactivity on cultured cells. Fresh PRP and PL were used as controls. The results showed an increase in platelet size (p < .01) and clot elasticity (p < .01), as well as decrease in levels of PDGF (P < .05) and VEGF (p < .05), though the overall bioactivity was not affected as culture cells showed the same responsiveness to both frozen and fresh PRP and PL in terms of cell viability. Based on these results, it could be assumed that preservation of PRP by freezing is a feasible and suitable option for its further use.

What is the context? Platelet-Rich Plasma (PRP) is a biological treatment widely used in regenerative medicine as a result of its high content of growth factors.In its routine use, PRP has autologous character, since it is obtained from the same patient and its infiltration in the affected area takes place immediately after it is obtained.Its storability would give PRP versatility in use, which could enable a potential allogeneic use and even significantly reduce the number of blood draws for each patient.It is necessary to establish a PRP storage protocol where its properties are not affected.What is new? PRP was stored at two time points (1 and 3 months) and temperatures (−20ºC and −80ºC) in activated and unactivated states. Afterwards, platelet number, size and activation were measured. Furthermore, the biomechanical properties of the resulting clot, the growth factor content and PRP's impact on cell viability were analyzed.The limiting factor was not having used aggregometry or other techniques that measure other cellular processes, as well as the limited sample size.The results showed that freezing affected platelet size, the levels of platelet-derived GFs and the biomechanical properties of the clot. However, plasmatic levels of growth factors or its capacity to boost cellular proliferation were not affected.What is the impact?The clinical impact of this work is the ability to preserve PRP by freezing. This is especially relevant as it allows a possible use of PRP as an allogeneic treatment. Moreover, its preservation significantly reduces the number of blood draws for each patient, especially in those with puncture difficulties or with apprehension.

Isolated lateral extra-articular tenodesis in ACL-deficient knees: in vivo knee kinematics and clinical outcomes.

PURPOSE: To carry out an in vivo kinematic analysis of isolated modified Lemaire lateral extra-articular tenodesis (LET) to explore its ability to modify the stability of anterior cruciate ligament (ACL) deficient knees. The secondary aim was to look at the clinical outcomes of the isolated LET to analyze whether biomechanical changes have an influence on clinical improvement or not. METHODS: A total of 52 patients who underwent an isolated modified Lemaire LET were prospectively studied. Twenty-two were over 55-year-old patients with ACL rupture and subjective instability (group 1). They were followed up for 2 years postoperatively. Thirty were patients underwent a two-stage ACL revision (group 2). They were followed up for 4 months postoperatively (up to the second stage of the ACL revision). Preoperative, intraoperative, and postoperative kinematic analyses were carried out using the KiRA accelerometer and KT1000 arthrometer to look for residual anterolateral rotational instability and residual anteroposterior instability. Functional outcomes were measured with the single-leg vertical jump test (SLVJT) and the single-leg hop test (SLHT). Clinical outcomes were evaluated using the IKDC 2000, Lysholm, and Tegner scores. RESULTS: A significant reduction of both rotational and anteroposterior instability was detected. It was present both with the patient under anesthesia (p < 0.001 and p = 0.007 respectively) as well as with the patient awake (p = 0.008 and p = 0.018 respectively). Postoperative analysis of knee laxity did not show any significant variation from the first to the last follow-up. Both the SLVJT and SLHT improved significantly at the last follow-up (p < 0.001 and p = 0.011 respectively). The mean values of both the IKDC and Lysholm and Tegner scores showed an improvement (p = 0.008; p = 0.012; p < 0.001). CONCLUSION: The modified Lemaire LET improves the kinematics of ACL-deficient knees. The improvement in the kinematics leads to an improvement in subjective stability as well as in the function of the knee and in the clinical outcomes. At the 2-year follow-up, these improvements were maintained in a cohort of patients over 55 years. Following our findings, to reduce knee instability, an isolated LET in ACL-deficient knees may be used when ACL reconstruction in patients over 55 years is not indicated. LEVEL OF EVIDENCE: Level IV.

Accuracy of Magnetic Resonance Imaging in the Diagnosis of Multiple Ligament Knee Injuries: A Multicenter Study of 178 Patients.

BACKGROUND: Magnetic resonance imaging (MRI) has shown limited diagnostic accuracy for multiple ligament knee injuries (MLKIs), especially posterolateral corner (PLC) injuries. HYPOTHESIS: The diagnostic accuracy of MRI for MLKIs will only be moderate for some knee structures. Patient-related factors and injury patterns could modify the diagnostic accuracy of MRI. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: All patients with MLKIs surgically treated between January 2014 and December 2020 in the centers participating in the study were reviewed. We recorded sex, age, mechanism of injury, time from injury to MRI, and vascular and neurological associated lesions. Lesions to the anterior cruciate ligament (ACL), posterior cruciate ligament, medial collateral ligament, lateral collateral ligament (LCL), popliteus tendon, popliteofibular ligament, iliotibial band, biceps tendon, medial and lateral meniscus, and articular cartilage from MRI reports and surgical records were also collected. The sensitivity, specificity, positive predictive value, negative predictive value, diagnostic accuracy, diagnostic odds ratio, positive and negative likelihood ratio, and intraclass correlation coefficient of MRI were calculated for each knee structure. With logistic regression, associations between patient and injury characteristics and MRI accuracy were assessed. RESULTS: A total of 178 patients (127 male; mean age, 33.1 years) were included. High-energy trauma was the most common mechanism of injury (50.6%), followed by sports trauma (38.8%) and low-energy trauma (8.4%). The ACL was the structure with the best diagnostic accuracy, diagnostic odds ratio, and positive predictive value (94.4%, 113.2, and 96.8%, respectively). PLC structures displayed the worst diagnostic accuracy among knee ligaments (popliteus tendon: 76.2%; LCL: 80.3%) and diagnostic odds ratio (popliteus tendon: 9.9; LCL: 17.0; popliteofibular ligament: 17.5). MRI was more reliable in detecting the absence of meniscal and chondral lesions than in identifying them. Logistic regression found that the diagnostic accuracy was affected by the Schenck classification, with higher Schenck grades having worse diagnostic accuracy for peripheral structures (iliotibial band, popliteus tendon, and biceps tendon) and improved diagnostic accuracy for the ACL and posterior cruciate ligament. CONCLUSION: The diagnostic accuracy of MRI for MLKIs largely varied among knee structures, with many of them at risk of a misdiagnosis, especially PLC, meniscal, and chondral lesions. The severity of MLKIs lowered the diagnostic accuracy of MRI for peripheral structures.

Effectiveness of Conservative Interventions After Acute Hamstrings Injuries in Athletes: A Living Systematic Review.

BACKGROUND: Hamstrings injuries are common in sports and the reinjury risk is high. Despite the extensive literature on hamstrings injuries, the effectiveness of the different conservative (i.e., non-surgical) interventions (i.e., modalities and doses) for the rehabilitation of athletes with acute hamstrings injuries is unclear. OBJECTIVE: We aimed to compare the effects of different conservative interventions in time to return to sport (TRTS) and/or time to return to full training (TRFT) and reinjury-related outcomes after acute hamstrings injuries in athletes. DATA SOURCES: We searched CINAHL, Cochrane Library, EMBASE, PubMed, Scopus, SPORTDiscus, and Web of Science databases up to 1 January, 2022, complemented with manual searches, prospective citation tracking, and consultation of external experts. ELIGIBILITY CRITERIA: The eligibility criteria were multi-arm studies (randomized and non-randomized) that compared conservative treatments of acute hamstrings injuries in athletes. DATA ANALYSIS: We summarized the characteristics of included studies and conservative interventions and analyzed data for main outcomes (TRTS, TRFT, and rate of reinjuries). The risk of bias was judged using the Cochrane tools. Quality and completeness of reporting of therapeutic exercise programs were appraised with the i-CONTENT tool and the certainty of evidence was judged using the GRADE framework. TRTS and TRFT were analyzed using mean differences and the risk of reinjury with relative risks. RESULTS: Fourteen studies (12 randomized and two non-randomized) comprising 730 athletes (mostly men with ages between 14 and 49 years) from different sports were included. Nine randomized studies were judged at high risk and three at low risk of bias, and the two non-randomized studies were judged at critical risk of bias. Seven randomized studies compared exercise-based interventions (e.g., L-protocol vs C-protocol), one randomized study compared the use of low-level laser therapy, and three randomized and two non-randomized studies compared injections of platelet-rich plasma to placebo or no injection. These low-level laser therapy and platelet-rich plasma studies complemented their interventions with an exercise program. Only three studies were judged at low overall risk of ineffectiveness (i-CONTENT). No single intervention or combination of interventions proved superior in achieving a faster TRTS/TRFT or reducing the risk of reinjury. Only eccentric lengthening exercises showed limited evidence in allowing a shorter TRFT. The platelet-rich plasma treatment did not consistently reduce the TRFT or have any effect on the risk of new hamstrings injuries. The certainty of evidence was very low for all outcomes and comparisons. CONCLUSIONS: Available evidence precludes the prioritization of a particular exercise-based intervention for athletes with acute hamstrings injuries, as different exercise-based interventions showed comparable effects on TRTS/TRFT and the risk of reinjuries. Available evidence also does not support the use of platelet-rich plasma or low-level laser therapy in clinical practice. The currently available literature is limited because of the risk of bias, risk of ineffectiveness of exercise protocols (as assessed with the i-CONTENT), and the lack of comparability across existing studies. CLINICAL TRIAL REGISTRATION: PROSPERO CRD42021268499 and OSF ( https://osf.io/3k4u2/ ).