Mile End Hospital

This paper describes a study to assess the influence of a variety of factors on reported level of presence in immersive virtual environments. It introduces the idea of “stacking depth,” that is, where a participant can simulate the process of entering the virtual environment while already in such an environment, which can be repeated to several levels of depth. An experimental study including 24 subjects was carried out. Half of the subjects were transported between environments by using virtual head-mounted displays, and the other half by going through doors. Three other binary factors were whether or not gravity operated, whether or not the subject experienced a virtual precipice, and whether or not the subject was followed around by a virtual actor. Visual, auditory, and kinesthetic representation systems and egocentric/exocentric perceptual positions were assessed by a preexperiment questionnaire. Presence was assessed by the subjects as their sense of “being there,” the extent to which they experienced the virtual environments as more the presenting reality than the real world in which the experiment was taking place, and the extent to which the subject experienced the virtual environments as places visited rather than images seen. A logistic regression analysis revealed that subjective reporting of presence was significantly positively associated with visual and kinesthetic representation systems, and negatively with the auditory system. This was not surprising since the virtual reality system used was primarily visual. The analysis also showed a significant and positive association with stacking level depth for those who were transported between environments by using the virtual HMD, and a negative association for those who were transported through doors. Finally, four of the subjects moved their real left arm to match movement of the left arm of the virtual body displayed by the system. These four scored significantly higher on the kinesthetic representation system than the remainder of the subjects.

This review analyzes the literature of bone grafts and introduces tissue engineering as a strategy in this field of orthopedic surgery. We evaluated articles concerning bone grafts; analyzed characteristics, advantages, and limitations of the grafts; and provided explanations about bone-tissue engineering technologies. Many bone grafting materials are available to enhance bone healing and regeneration, from bone autografts to graft substitutes; they can be used alone or in combination. Autografts are the gold standard for this purpose, since they provide osteogenic cells, osteoinductive growth factors, and an osteoconductive scaffold, all essential for new bone growth. Autografts carry the limitations of morbidity at the harvesting site and limited availability. Allografts and xenografts carry the risk of disease transmission and rejection. Tissue engineering is a new and developing option that had been introduced to reduce limitations of bone grafts and improve the healing processes of the bone fractures and defects. The combined use of scaffolds, healing promoting factors, together with gene therapy, and, more recently, three-dimensional printing of tissue-engineered constructs may open new insights in the near future.

Sarcopenia reflects a progressive withdrawal of anabolism and an increased catabolism, along with a reduced muscle regeneration capacity. Muscle force and power decline more than muscle dimensions: older muscle is intrinsically weak. Sarcopenic obesity (SO) among the elderly corroborates to the loss of muscle mass increasing the risk of metabolic syndrome development. Recent studies on the musculoskeletal adaptations with ageing and key papers on the mechanisms of muscle wasting, its functional repercussions and on SO are included. Neuropathic, hormonal, immunological, nutritional and physical activity factors contribute to sarcopenia. Selective fast fibre atrophy, loss of motor units and an increase in hybrid fibres are typical findings of ageing. Satellite cell number decreases reducing muscle regeneration capacity. SO promotes further muscle wasting and increases risk of metabolic syndrome development. The proportion of fast to slow fibres seems maintained in old age. In elderly humans, nuclear domain is maintained constant. Basal protein synthesis and breakdown show little changes in old age. Instead, blunting of the anabolic response to feeding and exercise and of the antiproteolytic effect of insulin is observed. Further understanding of the mechanisms of sarcopenia requires disentangling of the effects of ageing alone from those of disuse and disease. The causes of the greater anabolic resistance to feeding and exercise of elderly women need elucidating. The enhancement of muscle regeneration via satellite cell activation via the MAPK/notch molecular pathways seems particularly promising.

Muscle tissue may be damaged following intense prolonged training as a consequence of both metabolic and mechanical factors. Serum levels of skeletal muscle enzymes or proteins are markers of the functional status of muscle tissue, and vary widely in both pathological and physiological conditions. Creatine kinase, lactate dehydrogenase, aldolase, myoglobin, troponin, aspartate aminotransferase, and carbonic anhydrase CAIII are the most useful serum markers of muscle injury, but apoptosis in muscle tissues subsequent to strenuous exercise may be also triggered by increased oxidative stress. Therefore, total antioxidant status can be used to evaluate the level of stress in muscle by other markers, such as thiobarbituric acid-reactive substances, malondialdehyde, sulfhydril groups, reduced glutathione, oxidized glutathione, superoxide dismutase, catalase and others. As the various markers provide a composite picture of muscle status, we recommend using more than one to provide a better estimation of muscle stress.

BACKGROUND: After reinsertion on the humerus, the rotator cuff has limited ability to heal. Growth factor augmentation has been proposed to enhance healing in such procedure. PURPOSE: This study was conducted to assess the efficacy and safety of growth factor augmentation during rotator cuff repair. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: Eighty-eight patients with a rotator cuff tear were randomly assigned by a computer-generated sequence to receive arthroscopic rotator cuff repair without (n = 45) or with (n = 43) augmentation with autologous platelet-rich fibrin matrix (PRFM). The primary end point was the postoperative difference in the Constant score between the 2 groups. The secondary end point was the integrity of the repaired rotator cuff, as evaluated by magnetic resonance imaging. Analysis was on an intention-to-treat basis. RESULTS: All the patients completed follow-up at 16 months. There was no statistically significant difference in total Constant score when comparing the results of arthroscopic repair of the 2 groups (95% confidence interval, -3.43 to 3.9) (P = .44). There was no statistically significant difference in magnetic resonance imaging tendon score when comparing arthroscopic repair with or without PRFM (P = .07). CONCLUSION: Our study does not support the use of autologous PRFM for augmentation of a double-row repair of a small or medium rotator cuff tear to improve the healing of the rotator cuff. Our results are applicable to small and medium rotator cuff tears; it is possible that PRFM may be beneficial for large and massive rotator cuff tears. Also, given the heterogeneity of PRFM preparation products available on the market, it is possible that other preparations may be more effective.

UNLABELLED: Total ankle arthroplasty provides an alternative to arthrodesis for management of ankle arthritis. What is the outcome of total ankle arthroplasty implants currently in use? We conducted a systematic literature search of studies reporting on the outcome of total ankle arthroplasty. We included peer-reviewed studies reporting on at least 20 total ankle arthroplasties with currently used implants, with a minimum followup of 2 years. The Coleman Methodology Score was used to evaluate the quality of the studies. Thirteen Level IV studies of overall good quality reporting on 1105 total ankle arthroplasties (234 Agility, 344 STAR, 153 Buechel-Pappas, 152 HINTEGRA, 98 Salto, 70 TNK, 54 Mobility) were included. Residual pain was common (range, 27%-60%), superficial wound complications occurred in 0% to 14.7%, deep infections occurred in 0% to 4.6% of ankles, and ankle function improved after total ankle arthroplasty. The overall failure rate was approximately 10% at 5 years with a wide range (range, 0%-32%) between different centers. Superiority of an implant design over another cannot be supported by the available data. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

BACKGROUND: Osteoarthritis (OA) is the most orthopedic condition. The pattern of gene expression and the transcription factors that exert control of chondrogenesis have been extensively studied. SOURCES OF DATA: A systematic search (up to July 2018) of articles assessing the role of microRNA (miRNA) in physiopathology, diagnosis and therapy of OA was performed, with the purpose of giving a critical perspective of the possibilities for diagnostic and therapeutic use of miRNA in the management of OA. AREAS OF AGREEMENT: miRNAs are small noncoding RNAs that can regulate gene expression in human cells. miRNAs can be expressed in a different fashion in osteoarthritic compared to nonosteoarthritic cartilage. AREAS OF CONTROVERSY: The mechanisms that produce alteration of gene expression in OA are still not completely understood. miRNAs may be involved in the diagnosis of OA as well as in its treatment. GROWING POINTS: There are complex interactions between miRNAs and their multiple target genes. These interactions may be important in gene regulation and the control of homeostatic pathways in OA. AREAS TIMELY FOR DEVELOPING RESEARCH: miRNA could be useful for diagnostic or management purposes, but the issue of delivery of miRNA targeting agents needs to be overcome before miRNA can be applied in clinical practice.

The terminology of Achilles tendon pathology has become inconsistent and confusing throughout the years. For proper research, assessment and treatment, a uniform and clear terminology is necessary. A new terminology is proposed; the definitions hereof encompass the anatomic location, symptoms, clinical findings and histopathology. It comprises the following definitions: Mid-portion Achilles tendinopathy: a clinical syndrome characterized by a combination of pain, swelling and impaired performance. It includes, but is not limited to, the histopathological diagnosis of tendinosis. Achilles paratendinopathy: an acute or chronic inflammation and/or degeneration of the thin membrane around the Achilles tendon. There are clear distinctions between acute paratendinopathy and chronic paratendinopathy, both in symptoms as in histopathology. Insertional Achilles tendinopathy: located at the insertion of the Achilles tendon onto the calcaneus, bone spurs and calcifications in the tendon proper at the insertion site may exist. Retrocalcaneal bursitis: an inflammation of the bursa in the recess between the anterior inferior side of the Achilles tendon and the posterosuperior aspect of the calcaneus (retrocalcaneal recess). Superficial calcaneal bursitis: inflammation of the bursa located between a calcaneal prominence or the Achilles tendon and the skin. Finally, it is suggested that previous terms as Haglund's disease; Haglund's syndrome; Haglund's deformity; pump bump (calcaneus altus; high prow heels; knobbly heels; cucumber heel), are no longer used.

INTRODUCTION: The regulatory role of microRNA (miRNA) in several conditions has been studied, but their function in tendon healing remains elusive. This review summarizes how miRNAs are related to the pathogenesis of tendon injuries and highlights their clinical potential, focusing on the issues related to their delivery for clinical purposes. SOURCES OF DATA: We searched multiple databases to perform a systematic review on miRNA in relation to tendon injuries. We included in the present work a total of 15 articles. AREAS OF AGREEMENT: The mechanism of repair of tendon injuries is probably mediated by resident tenocytes. These maintain a fine equilibrium between anabolic and catabolic events of the extracellular matrix. Specific miRNAs regulate cytokine expression and orchestrate proliferation and differentiation of stromal cell lines involved in the composition of the extracellular matrix. AREAS OF CONTROVERSY: The lack of effective delivery systems poses serious obstacles to the clinical translation of these basic science findings. GROWING POINT: In vivo studies should be planned to better explore the relationship between miRNA and tendon injuries and evaluate the most suitable delivery system for these molecules. AREAS TIMELY FOR DEVELOPING RESEARCH: Investigations ex vivo suggest therapeutic opportunities of miRNA for the management of tendon injuries. Given the poor pharmacokinetic properties of miRNAs, these must be delivered by an adequate adjuvant transport system.

Injuries can counter the beneficial effects of sports participation at a young age if a child or adolescent is unable to continue to participate because of residual effects of injury. This paper reviews current knowledge in the field of long-term health outcomes of youth sports injuries to evaluate the evidence regarding children dropping out of sport due to injury, physeal injuries and growth disturbance, studies of injuries affecting the spine and knee of young and former athletes and surgical outcome of anterior cruciate ligament (ACL) reconstruction in children. Studies of dropping out of sport due to injury are limited primarily to gymnasts and implicate such injuries as ACL rupture and osteochondritis dissecans of the elbow joint in the early retirement of young athletes. Although most physeal injuries resolve with treatment and rest, there is evidence of disturbed physeal growth as a result of injury. Radiological findings implicate the effects of intense physical loading and injury in the development of spinal pathology and back pain during the growth of youth athletes; however, long-term effects are unclear. Follow-up studies of young athletes and adults indicate a high risk of osteoarthritis after meniscus or ACL injury. Prospective cohort studies with a follow-up into adulthood are needed to clarify the long-term health outcomes of youth sports injuries. Important to this research is meticulous documentation of injuries on injury report forms that include age-appropriate designations of the type of injury and accurate determination of exposure-based injury rates.

BACKGROUND: Tenogenesis and tendon homeostasis are guided by genes encoding for the structural molecules of tendon fibres. Small interfering RNAs (siRNAs), acting on gene regulation, can therefore participate in the process of tendon healing. SOURCES OF DATA: A systematic search of different databases to October 2020 identified 17 suitable studies. AREAS OF AGREEMENT: SiRNAs can be useful to study reparative processes of tendons and identify possible therapeutic targets in tendon healing. AREAS OF CONTROVERSY: Many genes and growth factors involved in the processes of tendinopathy and tendon healing can be regulated by siRNAs. It is however unclear which gene silencing determines the expected effect. GROWING POINTS: Gene dysregulation of growth factors and tendon structural proteins can be influenced by siRNA. AREAS TIMELY FOR DEVELOPING RESEARCH: It is not clear whether there is a direct action of the siRNAs that can be used to facilitate the repair processes of tendons.

BACKGROUND: Although targeted biological treatments have transformed the outlook for patients with rheumatoid arthritis, 40% of patients show poor clinical response, which is mechanistically still unexplained. Because more than 50% of patients with rheumatoid arthritis have low or absent CD20 B cells-the target for rituximab-in the main disease tissue (joint synovium), we hypothesised that, in these patients, the IL-6 receptor inhibitor tocilizumab would be more effective. The aim of this trial was to compare the effect of tocilizumab with rituximab in patients with rheumatoid arthritis who had an inadequate response to anti-tumour necrosis factor (TNF) stratified for synovial B-cell status. METHODS: This study was a 48-week, biopsy-driven, multicentre, open-label, phase 4 randomised controlled trial (rituximab vs tocilizumab in anti-TNF inadequate responder patients with rheumatoid arthritis; R4RA) done in 19 centres across five European countries (the UK, Belgium, Italy, Portugal, and Spain). Patients aged 18 years or older who fulfilled the 2010 American College of Rheumatology and European League Against Rheumatism classification criteria for rheumatoid arthritis and were eligible for treatment with rituximab therapy according to UK National Institute for Health and Care Excellence guidelines were eligible for inclusion in the trial. To inform balanced stratification, following a baseline synovial biopsy, patients were classified histologically as B-cell poor or rich. Patients were then randomly assigned (1:1) centrally in block sizes of six and four to receive two 1000 mg rituximab infusions at an interval of 2 weeks (rituximab group) or 8 mg/kg tocilizumab infusions at 4-week intervals (tocilizumab group). To enhance the accuracy of the stratification of B-cell poor and B-cell rich patients, baseline synovial biopsies from all participants were subjected to RNA sequencing and reclassified by B-cell molecular signature. The study was powered to test the superiority of tocilizumab over rituximab in the B-cell poor population at 16 weeks. The primary endpoint was defined as a 50% improvement in Clinical Disease Activity Index (CDAI50%) from baseline. The trial is registered on the ISRCTN database, ISRCTN97443826, and EudraCT, 2012-002535-28. FINDINGS: Between Feb 28, 2013, and Jan 17, 2019, 164 patients were classified histologically and were randomly assigned to the rituximab group (83 [51%]) or the tocilizumab group (81 [49%]). In patients histologically classified as B-cell poor, there was no statistically significant difference in CDAI50% between the rituximab group (17 [45%] of 38 patients) and the tocilizumab group (23 [56%] of 41 patients; difference 11% [95% CI -11 to 33], p=0·31). However, in the synovial biopsies classified as B-cell poor with RNA sequencing the tocilizumab group had a significantly higher response rate compared with the rituximab group for CDAI50% (rituximab group 12 [36%] of 33 patients vs tocilizumab group 20 [63%] of 32 patients; difference 26% [2 to 50], p=0·035). Occurrence of adverse events (rituximab group 76 [70%] of 108 patients vs tocilizumab group 94 [80%] of 117 patients; difference 10% [-1 to 21) and serious adverse events (rituximab group 8 [7%] of 108 vs tocilizumab group 12 [10%] of 117; difference 3% [-5 to 10]) were not significantly different between treatment groups. INTERPRETATION: The results suggest that RNA sequencing-based stratification of rheumatoid arthritis synovial tissue showed stronger associations with clinical responses compared with histopathological classification. Additionally, for patients with low or absent B-cell lineage expression signature in synovial tissue tocilizumab is more effective than rituximab. Replication of the results and validation of the RNA sequencing-based classification in independent cohorts is required before making treatment recommendations for clinical practice. FUNDING: Efficacy and Mechanism Evaluation programme from the UK National Institute for Health Research.

BACKGROUND: The absence of a single, identifiable traumatic cause has been traditionally used as a definition for a causative factor of overuse injury. Excessive loading, insufficient recovery, and underpreparedness can increase injury risk by exposing athletes to relatively large changes in load. The musculoskeletal system, if subjected to excessive stress, can suffer from various types of overuse injuries which may affect the bone, muscles, tendons, and ligaments. METHODS: We performed a search (up to March 2018) in the PubMed and Scopus electronic databases to identify the available scientific articles about the pathophysiology and the incidence of overuse sport injuries. For the purposes of our review, we used several combinations of the following keywords: overuse, injury, tendon, tendinopathy, stress fracture, stress reaction, and juvenile osteochondritis dissecans. RESULTS: Overuse tendinopathy induces in the tendon pain and swelling with associated decreased tolerance to exercise and various types of tendon degeneration. Poor training technique and a variety of risk factors may predispose athletes to stress reactions that may be interpreted as possible precursors of stress fractures. A frequent cause of pain in adolescents is juvenile osteochondritis dissecans (JOCD), which is characterized by delamination and localized necrosis of the subchondral bone, with or without the involvement of articular cartilage. The purpose of this compressive review is to give an overview of overuse injuries in sport by describing the theoretical foundations of these conditions that may predispose to the development of tendinopathy, stress fractures, stress reactions, and juvenile osteochondritis dissecans and the implication that these pathologies may have in their management. CONCLUSIONS: Further research is required to improve our knowledge on tendon and bone healing, enabling specific treatment strategies to be developed for the management of overuse injuries.

BACKGROUND: Lateral ankle sprains account for 85% of ankle lesions. HYPOTHESIS: Combined open and arthroscopic procedures could improve the diagnosis and management of intra-articular lesions and allow surgeons to perform minimally invasive anatomic reconstruction of the lateral ligament complex. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Forty consecutive patients underwent ankle arthroscopy for recurrent (2 or more episodes) lateral ankle instability unresponsive to nonoperative measures. The clinical diagnosis of mechanical instability was confirmed at imaging (plain radiographs and magnetic resonance imaging [MRI]) and arthroscopic assessment. All patients underwent arthroscopic Broström-Gould repair for management of lateral ankle instability; secondary lesions were also managed. Postoperatively, the American Orthopaedic Foot & Ankle Society (AOFAS) score was administered to assess the functional status; clinical examination and conventional radiographs were performed in all patients. RESULTS: Thirty-eight patients were reviewed at an average postoperative follow-up of 9.8 years. The mean AOFAS score was 90 (range, 44-100) at the last follow-up. No significantly different outcomes were found in patients who had undergone microfractures for management of grade III to IV cartilage lesions compared with patients with no cartilage lesions. Postoperative AOFAS scores were graded as excellent and good in almost all patients (94.7%). Concerning failure rate, 2 patients (5.3%) reported a low AOFAS score: one patient underwent soft tissue removal for anterior impingement, and one received simultaneous medial ankle instability repair. CONCLUSION: The arthroscopic Broström-Gould-assisted technique could be a viable alternative to the gold-standard Broström-Gould procedure for anatomic repair of chronic lateral ankle instability and management of intra-articular lesions. Prospective randomized controlled trials are needed.

BACKGROUND: Nonoperative options for osteochondral lesions (OCLs) of the talar dome are limited, and currently, there is a lack of scientific evidence to guide management. PURPOSE: To evaluate the short-term efficacy and safety of platelet-rich plasma (PRP) compared with hyaluronic acid (HA) in reducing pain and disability caused by OCLs of the ankle. STUDY DESIGN: Randomized controlled trial; Level of evidence, 2. METHODS: Thirty-two patients aged 18 to 60 years were allocated to a treatment by intra-articular injections of either HA (group 1) or PRP (plasma rich in growth factors [PRGF] technique, group 2) for OCLs of the talus. Thirty OCLs, 15 per arm, received 3 consecutive intra-articular therapeutic injections and were followed for 28 weeks. The efficacy of the injections in reducing pain and improving function was assessed at each visit using the American Orthopaedic Foot and Ankle Society (AOFAS) Ankle-Hindfoot Scale (AHFS); a visual analog scale (VAS) for pain, stiffness, and function; and the subjective global function score. RESULTS: The majority of patients were men (n = 23; 79%). The AHFS score improved from 66 and 68 to 78 and 92 in groups 1 and 2, respectively, from baseline to week 28 (P < .0001), favoring PRP (P < .05). Mean VAS scores (1 = asymptomatic, 10 = severe symptoms) decreased for pain (group 1: 5.6 to 3.1; group 2: 4.1 to 0.9), stiffness (group 1: 5.1 to 2.9; group 2: 5.0 to 0.8), and function (group 1: 5.8 to 3.5; group 2: 4.7 to 0.8) from baseline to week 28 (P < .0001), favoring PRP (P < .05 for stiffness, P < .01 for function, P > .05 for pain). Subjective global function scores, reported on a scale from 0 to 100 (with 100 representing healthy, preinjury function) improved from 56 and 58 at baseline to 73 and 91 by week 28 for groups 1 and 2, respectively (P < .01 in favor of PRP). CONCLUSION: Osteochondral lesions of the ankle treated with intra-articular injections of PRP and HA resulted in a decrease in pain scores and an increase in function for at least 6 months, with minimal adverse events. Platelet-rich plasma treatment led to a significantly better outcome than HA.

The Achilles tendon is the strongest and thickest tendon in the human body. It is also the commonest tendon to rupture. It begins near the middle of the calf and is the conjoint tendon of the gastrocnemius and soleus muscles. The relative contribution of the two muscles to the tendon varies. Spiralisation of the fibres of the tendon produces an area of concentrated stress and confers a mechanical advantage. The calcaneal insertion is specialised and designed to aid the dissipation of stress from the tendon to the calcaneum. The insertion is crescent shaped and has significant medial and lateral projections. The blood supply of the tendon is from the musculotendinous junction, vessels in surrounding connective tissue and the osteotendinous junction. The vascular territories can be classified simply in three, with the midsection supplied by the peroneal artery, and the proximal and distal sections supplied by the posterior tibial artery. This leaves a relatively hypovascular area in the mid-portion of the tendon where most problems occur. The Achilles tendon derives its innervation from the sural nerve with a smaller supply from the tibial nerve. Tenocytes produce type I collagen and form 90% of the cellular component of the normal tendon. Evidence suggests ruptured or pathological tendon produce more type III collagen, which may affect the tensile strength of the tendon. Direct measurements of forces reveal loading in the Achilles tendon as high as 9 KN during running, which is up to 12.5 times body weight.

INTRODUCTION: Several biomaterials are available to bridge large tendon defects or reinforce tenuous tendon repairs. METHODS: We performed a comprehensive search of PubMed, Medline, Cochrane, CINAHL, and Embase databases using various combinations of the commercial names of each scaffold and the keywords 'tendon', 'rotator cuff', 'supraspinatus tendon', 'Achilles tendon', 'scaffold', 'biomaterials', 'extracellular matrix', 'substitute', and 'devices' over the years 1966-2009. All articles relevant to the subject were retrieved, and their bibliographies hand searched for further references in the context to biomaterials for tendon repair. RESULTS: Many biomaterials are available for tendon augmentation. Scanty evidence is available for the use of these scaffolds. DISCUSSION: The emerging field of tissue engineering holds the promise to use biomaterials for tendon augmentation. Preliminary studies support the idea that these biomaterials have the ability to provide an alternative for tendon augmentation. However, available data are lacking to allow definitive conclusion on the use of biomaterials for tendon augmentation. Additionally, the prevalence of postoperative complications encountered with their use varies within the different studies. CONCLUSION: Rather than providing strong evidence for or against the use of these materials for tendon augmentation, this study instead generates potential areas for additional prospective investigation.

condition associated with high levels of disability and mortality. It has a neurobiological basis and is associated with functional and structural brain abnormalities. Sources of data: The data discussed have been obtained mainly from meta-

Injuries can counter the beneficial aspects related to sports activities if an athlete is unable to continue to participate because of residual effects of injury. We provide an updated synthesis of existing clinical evidence of long-term follow-up outcome of sports injuries. A systematic computerized literature search was conducted on following databases were accessed: PubMed, Medline, Cochrane, CINAHL and Embase databases. At a young age, injury to the physis can result in limb deformities and leg-length discrepancy. Weight-bearing joints including the hip, knee and ankle are at risk of developing osteoarthritis (OA) in former athletes, after injury or in the presence of malalignment, especially in association with high impact sport. Knee injury is a risk factor for OA. Ankle ligament injuries in athletes result in incomplete recovery (up to 40% at 6 months), and OA in the long term (latency period more than 25 years). Spine pathologies are associated more commonly with certain sports (e.g. wrestling, heavy-weight lifting, gymnastics, tennis, soccer). Evolution in arthroscopy allows more accurate assessment of hip, ankle, shoulder, elbow and wrist intra-articular post-traumatic pathologies, and possibly more successful management. Few well-conducted studies are available to establish the long-term follow-up of former athletes. To assess whether benefits from sports participation outweigh the risks, future research should involve questionnaires regarding the health-related quality of life in former athletes, to be compared with the general population.

An experiment is described which investigated cognitive inhibition in schizophrenia. It is noted that both the abnormal and cognitive literatures use the concept of inhibition. Frith (1979) suggests that the more cognitive symptoms of schizophrenia may be due to the failure to limit the current contents of consciousness due to a failure adequately to inhibit the output of preconscious processes. Current thinking in cognitive psychology suggests that in the process of selective attention there is active inhibition of distractor information. A technique used to investigate this is termed negative priming (Tipper, 1985). The general nature of this paradigm is as follows: if a distractor, which has been previously ignored, is response, due to inhibition of the information when it was originally a distractor. It was found that inhibition of such distracting information was reduced in schizophrenics. This finding is seen as providing some support for Frith's (1979) theory that the cognitive symptoms of schizophrenia are due to awareness of processes that normally occur preconsciously.