Soft tissue tumor imaging in adults: European Society of Musculoskeletal Radiology-Guidelines 2023-overview, and primary local imaging: how and where?

OBJECTIVES: Early, accurate diagnosis is crucial for the prognosis of patients with soft tissue sarcomas. To this end, standardization of imaging algorithms, technical requirements, and reporting is therefore a prerequisite. Since the first European Society of Musculoskeletal Radiology (ESSR) consensus in 2015, technical achievements, further insights into specific entities, and the revised WHO-classification (2020) and AJCC staging system (2017) made an update necessary. The guidelines are intended to support radiologists in their decision-making and contribute to interdisciplinary tumor board discussions. MATERIALS AND METHODS: A validated Delphi method based on peer-reviewed literature was used to derive consensus among a panel of 46 specialized musculoskeletal radiologists from 12 European countries. Statements were scored online by level of agreement (0 to 10) during two iterative rounds. Either "group consensus," "group agreement," or "lack of agreement" was achieved. RESULTS: Eight sections were defined that finally contained 145 statements with comments. Overall, group consensus was reached in 95.9%, and group agreement in 4.1%. This communication contains the first part consisting of the imaging algorithm for suspected soft tissue tumors, methods for local imaging, and the role of tumor centers. CONCLUSION: Ultrasound represents the initial triage imaging modality for accessible and small tumors. MRI is the modality of choice for the characterization and local staging of most soft tissue tumors. CT is indicated in special situations. In suspicious or likely malignant tumors, a specialist tumor center should be contacted for referral or teleradiologic second opinion. This should be done before performing a biopsy, without exception. CLINICAL RELEVANCE: The updated ESSR soft tissue tumor imaging guidelines aim to provide best practice expert consensus for standardized imaging, to support radiologists in their decision-making, and to improve examination comparability both in individual patients and in future studies on individualized strategies. KEY POINTS: • Ultrasound remains the best initial triage imaging modality for accessible and small suspected soft tissue tumors. • MRI is the modality of choice for the characterization and local staging of soft tissue tumors in most cases; CT is indicated in special situations. Suspicious or likely malignant tumors should undergo biopsy. • In patients with large, indeterminate or suspicious tumors, a tumor reference center should be contacted for referral or teleradiologic second opinion; this must be done before a biopsy.

Comparison of the movement behaviour of experienced and novice performers during the Cat exercise.

Two previous studies showed kinematic differences between novice and experienced performers during unchoreographed movements executed in standing position. However, no study explores if these kinematic differences holds during unchoreographed movements executed in quadrupedal position. The aim of this study is to compare the movement behaviour of experienced and novice performers during an exercise wherein they are challenged to use dynamic and largely unchoreographed movement patterns executed in quadrupedal position. The exercise studied was the Cat exercise, in which participants were asked to behave like a feline for 10 minutes. An inventory of the chosen movements and the assessment of their average and coefficient of variation of the ground contact temporal parameters, computed by analysing the tri-dimensional whole-body kinematics of 25 performers (n = 13 novices and n = 12 experienced), was compared according to their experience level. No significant difference was found between the groups for the number of chosen movements, and median or coefficient of variation of ground contact temporal parameters, except for a greater foot/ knee swing coefficient of variation in experienced performers. This suggests that biomechanical constraints induced by quadrupedal position "prevent" a different selection of motor strategies by experienced performers, although the latter can be more variable in their movements.

Effect of BNT162b2 mRNA booster vaccination on VO2 max in recreational athletes: A prospective cohort study.

Background and Aims: The goal of the present study was to systematically evaluate the effect of a booster vaccination with the BNT162b2 messenger RNA (mRNA; Pfizer-BioNTech®) vaccine on maximum oxygen uptake (VO2 max), potential signs of (peri)myocarditis, and sports participation. Methods: Recreational athletes who were scheduled to undergo booster vaccination were evaluated with transthoracic echocardiography, serum measurements of high-sensitivity C-reactive protein(hsCRP) and high-sensitivity troponin I, and a bicycle cardiopulmonary exercise test (CPET) with serum lactate evaluation before the booster vaccine administration. Seven days postvaccination the test battery was repeated. Additionally, the subjects were asked to fill in a questionnaire on side effects and a subjective evaluation of their relative training volume and intensity as compared to the weeks before vaccination. Results: A group of 42 analysed athletes showed a statistically significant 2.7% decrease in VO2 max after vaccination (mean standard error of mean pre: 48.6 (1.4) ml/kg/min; post: 47.3 (1.4) ml/kg/min; p = 0.004). A potentially clinically relevant decrease of 8.6% or more occurred in 8 (19%) athletes. Other CPET parameters and lactate curves were comparable. We found no serological or echocardiographic evidence of (peri)myocarditis. A slight but significant increase in hsCRP was noted 1 week after vaccination. Side effects were mild and sports participation was generally unchanged or mildly decreased after vaccination. Conclusion: In our population of recreational endurance athletes, booster vaccination with the BNT162b2 mRNA vaccine resulted in a statistically significant decrease in VO2max 7 days after vaccination. The clinical impact hereof needs to be further determined. No major adverse events were observed.

Blood transcriptomics to facilitate diagnosis and stratification in pediatric rheumatic diseases - a proof of concept study.

BACKGROUND: Transcriptome profiling of blood cells is an efficient tool to study the gene expression signatures of rheumatic diseases. This study aims to improve the early diagnosis of pediatric rheumatic diseases by investigating patients' blood gene expression and applying machine learning on the transcriptome data to develop predictive models. METHODS: RNA sequencing was performed on whole blood collected from children with rheumatic diseases. Random Forest classification models were developed based on the transcriptome data of 48 rheumatic patients, 46 children with viral infection, and 35 controls to classify different disease groups. The performance of these classifiers was evaluated by leave-one-out cross-validation. Analyses of differentially expressed genes (DEG), gene ontology (GO), and interferon-stimulated gene (ISG) score were also conducted. RESULTS: Our first classifier could differentiate pediatric rheumatic patients from controls and infection cases with high area-under-the-curve (AUC) values (AUC = 0.8 ± 0.1 and 0.7 ± 0.1, respectively). Three other classifiers could distinguish chronic recurrent multifocal osteomyelitis (CRMO), juvenile idiopathic arthritis (JIA), and interferonopathies (IFN) from control and infection cases with AUC ≥ 0.8. DEG and GO analyses reveal that the pathophysiology of CRMO, IFN, and JIA involves innate immune responses including myeloid leukocyte and granulocyte activation, neutrophil activation and degranulation. IFN is specifically mediated by antibacterial and antifungal defense responses, CRMO by cellular response to cytokine, and JIA by cellular response to chemical stimulus. IFN patients particularly had the highest mean ISG score among all disease groups. CONCLUSION: Our data show that blood transcriptomics combined with machine learning is a promising diagnostic tool for pediatric rheumatic diseases and may assist physicians in making data-driven and patient-specific decisions in clinical practice.

Unsupervised Exercise Training Was Not Found to Improve the Metabolic Health or Phenotype over a 6-Month Dietary Intervention: A Randomised Controlled Trial with an Embedded Economic Analysis.

Ectopic fat leads to metabolic health problems. This research aimed to assess the effectiveness of a hypocaloric diet intervention together with an unsupervised exercise training program in comparison with a hypocaloric diet alone to reduce ectopic fat deposition. Sixty-one premenopausal women with overweight or obesity participated in this controlled trial and were each randomised into either a usual care group (hypocaloric diet) or intervention group (hypocaloric diet + unsupervised exercise training). Ectopic fat deposition, metabolic parameters, incremental costs from a societal perspective and incremental quality-adjusted life years (QALYs) were assessed before, during and after the six-month intervention period. In the total sample, there was a significant decrease in visceral adipose tissue (VAT: -18.88 cm2, 95% CI -11.82 to -25.95), subcutaneous abdominal adipose tissue (SAT: -46.74 cm2, 95% CI -29.76 to -63.18), epicardial fat (ECF: -14.50 cm3, 95% CI -10.9 to -18.98) and intrahepatic lipid content (IHL: -3.53%, 95% CI -1.72 to -5.32). Consequently, an "adapted" economic analysis revealed a non-significant decrease in costs and an increase in QALYs after the intervention. No significant differences were found between groups. A multidisciplinary lifestyle approach seems successful in reducing ectopic fat deposition and improving the metabolic risk profile in women with overweight and obesity. The addition of unsupervised exercise training did not further improve the metabolic health or phenotype over the six months.

EVALUATION OF A SUPERVISED PHYSICAL ACTIVITY PROGRAMME FOR CANCER SURVIVORS: FROM TREATMENT TO TRIATHLON.

OBJECTIVE: It is recommended that cancer survivors incorporate physical activity into their daily lives after in-hospital rehabilitation. However, there is a lack of training programmes focusing on the specific needs of cancer survivors. TriaGO! - an 8-month intervention study of aerobic endurance training for cancer survivors - was therefore examined. The training programme aims to meet the participants' physical needs and provide socio-emotional support, in the form of an exercise programme that challenges participants to aim to compete in an Olympic- distance triathlon (1,000 m swimming, 45 km cycling, 10 km running) after 8 months' of training. METHODS: The TriaGO! training programme was provided to in-hospital rehabilitated cancer survivors (n = 12). Each patient invited a healthy friend or family member to train with them (a so called buddy (n = 12)). The 8-month programme involves supervised training sessions, combining cycling, swimming and running, which progress in frequency, duration and intensity. Physical health was measured at the start, 4 and 8 months, using objective parameters of aerobic fitness, muscular fitness and body composition. RESULTS: A total of 22 out of 24 participants successfully completed the training programme and the triathlon. Both the cancer survivors and their buddies showed significant improvements in physical health. Cancer survivors showed improvements in aerobic fitness, as increases in VO2max and VO2peak of 5.5 ml.kg-1.min-1 and 0.26 ml.min-1 respectively (p <0.0001). Buddies underwent similar significant increases; 5.39 ml.kg-1.min-1 and 0.18 ml.min-1, respectively. CONCLUSION: The TriaGO! training programme introduces the concept of supervised endurance training for cancer survivors. Through measurement of ob-jective parameters, this study demonstrated that significant physical reconditioning is possible in cancer survivors. A supervised programme would be recommended for all cancer patients after in-hospital treatment, in order to facilitate the transition to incorporation of physical activity into daily life.

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-part I, shoulder.

BACKGROUND: Image-guided interventional procedures around the shoulder are commonly performed in clinical practice, although evidence regarding their effectiveness is scarce. We report the results of a Delphi method review of evidence on literature published on image-guided interventional procedures around the shoulder with a list of clinical indications. METHODS: Forty-five experts in image-guided musculoskeletal procedures from the ESSR participated in a consensus study using the Delphic method. Peer-reviewed papers regarding interventional procedures around the shoulder up to September 2018 were scored according to the Oxford Centre for Evidence-based Medicine levels of evidence. Statements on clinical indications were constructed. Consensus was considered as strong if more than 95% of experts agreed and as broad if more than 80% agreed. RESULTS: A total of 20 statements were drafted, and 5 reached the highest level of evidence. There were 10 statements about tendon procedures, 6 about intra-articular procedures, and 4 about intrabursal injections. Strong consensus was obtained in 16 of them (80%), while 4 received broad consensus (20%). CONCLUSIONS: Literature evidence on image-guided interventional procedures around the shoulder is limited. A strong consensus has been reached for 80% of statements. The ESSR recommends further research to potentially influence treatment options, patient outcomes, and social impact. KEY POINTS: • Expert consensus produced a list of 20 evidence-based statements on clinical indications of image-guided interventional procedures around the shoulder. • The highest level of evidence was reached for five statements. • Strong consensus was obtained for 16 statements (80%), while 4 received broad consensus (20%).

Arcuate Pubic Ligament Injury-An Unknown Cause of Athletic Pubalgia.

A case report is presented that gives new insight into a very rare cause of athletic pubalgia. Up till now, no case has been published in literature about the relevance of an arcuate pubic ligament (APL) injury in athletic pubalgia. The APL or inferior pubic ligament is a thick triangular arch of ligamentous fibers connecting the 2 pubic bones below. The main function of the APL is to stabilize the symphysis pubis. The rupture of this ligament can lead to groin pain due to lack of stabilization of the symphysis pubis. Despite the importance of the anatomical and clinical function of the APL, very limited research is available about injuries of this ligament. This report describes a case of a traumatic left APL rupture, confirmed by magnetic resonance imaging, causing longstanding left groin pain in an amateur athlete.

Clinical indications for image-guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-Part II, elbow and wrist.

BACKGROUND: Although image-guided interventional procedures of the elbow and wrist are routinely performed, there is poor evidence in the literature concerning such treatments. Our aim was to perform a Delphi-based consensus on published evidence on image-guided interventional procedures around the elbow and wrist and provide clinical indications on this topic. METHODS: A board of 45 experts in image-guided interventional musculoskeletal procedures from the European Society of Musculoskeletal Radiology were involved in this Delphi-based consensus study. All panelists reviewed and scored published papers on image-guided interventional procedures around the elbow and wrist updated to September 2018 according to the Oxford Centre for Evidence-based Medicine levels of evidence. Consensus on statements drafted by the panelists about clinical indications was considered as "strong" when more than 95% of panelists agreed and as "broad" if more than 80% agreed. RESULTS: Eighteen statements were drafted, 12 about tendon procedures and 6 about intra-articular procedures. Only statement #15 reached the highest level of evidence (ultrasound-guided steroid wrist injections result in greater pain reduction and greater likelihood of attaining clinically important improvement). Seventeen statements received strong consensus (94%), while one received broad consensus (6%). CONCLUSIONS: There is still poor evidence in published papers on image-guided interventional procedures around the elbow and wrist. A strong consensus has been achieved in 17/18 (94%) statements provided by the panel on clinical indications. Large prospective randomized trials are needed to better define the role of these procedures in clinical practice. KEY POINTS: • The panel provided 18 evidence-based statements on clinical indications of image-guided interventional procedures around the elbow and wrist. • Only statement #15 reached the highest level of evidence: ultrasound-guided steroid wrist injections result in greater pain reduction and greater likelihood of attaining clinically important improvement. • Seventeen statements received strong consensus (94%), while broad consensus was obtained by 1 statement (6%).

Clinical indications for image guided interventional procedures in the musculoskeletal system: a Delphi-based consensus paper from the European Society of Musculoskeletal Radiology (ESSR)-part III, nerves of the upper limb.

BACKGROUND: Image-guided interventional procedures of the nerves are commonly performed by physicians from different medical specialties, although there is a lack of clinical indications for these types of procedures. This Delphi-based consensus provided a list of indications on image-guided interventional procedures for nerves of the upper limb based on updated published evidence. METHODS: An expert panel of 45 members of the Ultrasound and Interventional Subcommittees of the ESSR participated in this Delphi-based consensus study. After revision of the published papers on image-guided interventional procedures for nerves of the upper limb updated to September 2018, the experts drafted a list of statements according to the Oxford Centre for evidence-based medicine levels of evidence. Consensus on statements regarding clinical indications was considered as strong when more than 95% of experts agreed, and broad if more than 80% agreed. RESULTS: Ten statements were drafted on procedures for nerves of the upper limb. Only two statements reached the highest level of evidence (ultrasound guidance is a safe and effective method for brachial plexus block; ultrasound-guided non-surgical approaches are safe and effective methods to treat carpal tunnel syndrome in the short term, but there is sparse evidence on the mid- and long-term effectiveness of these interventions). Strong consensus was obtained on 6/10 statements (60%), while 4/10 statements reached broad consensus (40%). CONCLUSIONS: This Delphi-based consensus study reported poor evidence on image-guided interventional procedures for nerves of the upper limb. Sixty percent of statements on clinical indications provided by the expert board reached a strong consensus. KEY POINTS: • An expert panel of the ESSR provided 10 evidence-based statements on clinical indications for image-guided interventional procedures for nerves of the upper limb • Two statements reached the highest level of evidence • Strong consensus was obtained on 6/10 statements (60%), while 4/10 statements reached broad consensus (40%).

European multicentre study on technical success and long-term clinical outcome of radiofrequency ablation for the treatment of spinal osteoid osteomas and osteoblastomas.

PURPOSE: To evaluate technical success and long-term outcome of CT-guided radiofrequency ablation (RFA) of spinal osteoid osteomas (OO) and osteoblastomas (OB) in six different European centres. METHODS: Eighty-seven patients with spinal OO (77) or OB (10) were treated with CT-guided RFA, after three-dimensional CT-guided access planning. Patient's long-term outcome was assessed by clinical examination and questionnaire-based evaluation including 10-point visual analogue scales (VAS) regarding the effect of RFA on severity of pain and limitations of daily activities. Clinical success was defined as a reduction of > 30% in the VAS score and patient's satisfaction. RESULTS: Overall, RFA was technically successful in 82/87 cases (94.3%) with no major complications; clinical success was achieved in 78/87 cases (89.7%). The OO/OB were localized in the cervical (n = 9/3), the thoracic (n = 27/1), the lumbar (n = 29/4), and the sacral spine (n = 12/2). A decrease in severity of pain after RFA was observed in 86/87 patients (98.9%) with a persistent mean reduction of overall pain score from 8.04 ± 0.96 to 1.46 ± 1.95 (p < 0.001) after a median follow-up time of 29.35 ± 35.59 months. VAS scores significantly decreased for limitations of both daily (5.70 ± 2.73 to 0.67 ± 1.61, p < 0.001) and sports activities (6.40 ± 2.58 to 0.67 ± 1.61, p < 0.001). CONCLUSION: In a multicentric setting, this trial proves RFA to be a safe and efficient method to treat spinal OO/OB and should be regarded as first-line therapy after interdisciplinary case discussion.

Correction to: European multicentre study on technical success and long-term clinical outcome of radiofrequency ablation for the treatment of spinal osteoid osteomas and osteoblastomas.

The original version of this paper contained an error: the Acknowledgements were dropped during early manuscript editing.

Clinical indications for musculoskeletal ultrasound updated in 2017 by European Society of Musculoskeletal Radiology (ESSR) consensus.

OBJECTIVES: To update the 2012 European Society of Musculoskeletal Radiology (ESSR) clinical consensus guidelines for musculoskeletal ultrasound referral in Europe. METHODS: Twenty-one musculoskeletal imaging experts from the ESSR participated in a consensus study based on a Delphic process. Two independent (non-voting) authors facilitated the procedure and resolved doubtful issues. Updated musculoskeletal ultrasound literature up to July 2017 was scored for shoulder, elbow, wrist/hand, hip, knee, and ankle/foot. Scoring of ultrasound elastography was included. The strength of the recommendation and level of evidence was scored by consensus greater than 67% or considered uncertain when the consensus was consensus less than 67%. RESULTS: A total of 123 new papers were reviewed. No evidence change was found regarding the shoulder. There were no new relevant articles for the shoulder, 10 new articles for the elbow, 28 for the hand/wrist, 3 for the hip, 7 for the knee, and 4 for the ankle/foot. Four new evidence levels of A were determined, one for the hip (gluteal tendons tears), one for the knee (meniscal cysts), one for the ankle (ankle joint instability), and one for the foot (plantar plate tear). There was no level A evidence for elastography, although for Achilles tendinopathy and lateral epicondylitis evidence level was B with grade 3 indication. CONCLUSIONS: Four new areas of level A evidence were included in the guidelines. Elastography did not reach level A evidence. Whilst ultrasound is of increasing importance in musculoskeletal medical practice, the evidence for elastography remains moderate. KEY POINTS: • Evidence and expert consensus shows an increase of musculoskeletal ultrasound indications. • Four new A evidence levels were found for the hip, knee, ankle, and foot. • There was no level A evidence for elastography.

Unravelling Motor Learning Processes in Theater Performers.

Theater performers, more than common actors, experience high physical loadings. This study aimed at analyzing the motor behavior of novice performers (dancers/actors who were introduced to the acting method of Jan Fabre) by investigating the kinematics of a physical acting exercise in a prospective study. Two measurement sessions were organized: before and after the novice performers (N = 13) took part in seven workshops. Total body kinematics were registered using a three-dimensional motion capture system. Using a principal component analysis, six factors were disseminated out of 30 kinematic parameters: Pelvic Motion, Speed of Progression, Lower Limb Position, Foot Motion, Lower Limb Motion, and Trunk Posture. Although no main effect of training was found for any of the factors (.429 < p < .964), Trunk Posture showed a higher consistency after the workshops. This study succeeded in providing insights in the motor behavior of theater performers and revealed recognizable features of motor learning.

Imaging modalities in the diagnosis and monitoring of Achilles tendon ruptures: A systematic review.

OBJECTIVE: To determine the role of imaging in the diagnosis and monitoring of the Achilles tendon rupture (ATR). STUDY DESIGN: Systematic review. DATA SOURCES: PubMed and EMBASE in November 2016. ELIGIBILITY CRITERIA: Clinical studies providing information on the methods and role of imaging in the diagnosis and monitoring of the ATR were included. RESULTS: Fifty-six studies were included, most concerning the use of ultrasound (n=37) or MRI (n=18). Seven studies provided data on the diagnostic accuracy of imaging. Most ultrasound studies used a 7.5MHz probe (19/32 studies) and scanned the patient bilaterally in prone position, with recent studies tending to use higher frequency probes (r=0.42). Sensitivity [for detecting a rupture] ranged from 79.6 to 100%; the spread in specificity was large but two studies showed perfect (100%) data. Negative and positive likelihood ratios ranged from 0 to 0.23 and 1.0 to 10 respectively. MRI examination was generally performed with 1.5Tesla (T) MRI (6/12 studies) with a strong trend for higher T strength in more recent studies (r=0.71). One study reported a sensitivity of 90.9% and one a specificity of 100%. Although imaging can visualize structure and healing, these results were generally not related to the clinical picture. Overall, ultrasound was recommended over MRI for diagnosis and monitoring. Results of other imaging modalities remain inconclusive. CONCLUSION: The adjunct role of imaging, especially of ultrasound and MRI, in the diagnosis and monitoring of ATRs was established. It is therefore recommended to rely primarily on the clinical examination and evaluation and to use imaging for ruling out other injuries and providing additional clinical information. More high-quality research is warranted into the diagnostic accuracy of imaging as well as less conventional imaging modalities' diagnostic and monitoring capabilities.

Do Performers' Experience and Sex Affect Their Performance?

This cross-sectional study aimed at developing a biomechanical method to objectify voluntary and unpredictable movements, using an automated three-dimensional motion capture system and surface electromyography. Fourteen experienced theater performers were tested while executing the old man exercise, wherein they have to walk like an old man, building up a sustained high intensive muscular activity and tremor. Less experienced performed showed a different kinematics of movement, a slower speed of progression and more variable EMG signals at higher intensity. Female performers also differed from males in movement kinematics and muscular activity. The number of the trial only influenced the speed of progression. The performers showed results which could be well placed within the stages of learning and the degrees of freedom problem.

Exploiting the Repetitive Fraction of the Wheat Genome for High-Throughput Single-Nucleotide Polymorphism Discovery and Genotyping.

Transposable elements (TEs) account for more than 80% of the wheat genome. Although they represent a major obstacle for genomic studies, TEs are also a source of polymorphism and consequently of molecular markers such as insertion site-based polymorphism (ISBP) markers. Insertion site-based polymorphisms have been found to be a great source of genome-specific single-nucleotide polymorphism (SNPs) in the hexaploid wheat ( L.) genome. Here, we report on the development of a high-throughput SNP discovery approach based on sequence capture of ISBP markers. By applying this approach to the reference sequence of chromosome 3B from hexaploid wheat, we designed 39,077 SNPs that are evenly distributed along the chromosome. We demonstrate that these SNPs can be efficiently scored with the KASPar (Kompetitive allele-specific polymerase chain reaction) genotyping technology. Finally, through genetic diversity and genome-wide association studies, we also demonstrate that ISBP-derived SNPs can be used in marker-assisted breeding programs.

The Anterolateral Ligament of the Knee: What the Radiologist Needs to Know.

The anterolateral ligament (ALL) was recently identified as a distinct component of the anterolateral capsule of the human knee joint with consistent origin and insertion sites. Biomechanical studies revealed that the current association between the pivot shift and an injured anterior cruciate ligament (ACL) should be loosened and that the rotational component of the pivot shift is significantly affected by the ALL. This may change the clinical approach toward ACL-injured patients presenting with anterolateral rotatory instability (ALRI), the most common instability pattern after ACL rupture. Radiologists should be aware of the importance of the ALL to ACL injuries. They should not overlook pathology of the anterolateral knee structures, including the ALL, when reviewing MR images of the ACL-deficient knee. In this article, the current knowledge regarding the anatomy, biomechanical function, and imaging appearance of the ALL of the knee is discussed with emphasis on the clinical implications of these findings.