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Background: This study aimed to measure and compare (1) the microcirculation and microcirculatory responses of the muscles and tendons at rest and during isometric muscle contractions in participan...

Objectives To evaluate the effects of vibration on Achilles’ tendon microcirculation and characteristics following surgical repair of Achilles’ tendon rupture. Design Cohort study with historical controls. Setting A university institute. Participants Participants (N=32), including 19 (16 men, 3 women; median [range] age: 43.0 [25.0-57.0] years) and 13 (10 men, 3 women; 44.00 [29.0-60.0] years) in the vibration (application to the ball of the foot, 30Hz, 2mm amplitude, 4kg pressure, and self-administration) and control groups, respectively, who underwent unilateral Achilles’ tendon repairs were recruited. Intervention A 4-week vibration intervention in the vibration group. Main Outcome Measurements The tendon microcirculation was measured after the first session of vibration. The participants were evaluated repeatedly with bilateral follow-up measurements of tendon stiffness, 3 functional outcome tests, and a questionnaire survey. Results Acute effects of the vibration were observed immediately after the 5-minute vibration (P≤.001). Lower total hemoglobin and oxygen saturation were respectively observed (P=.043) in the repaired legs 3 and 6 months postsurgery in the vibration group as compared with the control group. The vibration group also showed greater tendon stiffness, heel raising height and hopping distance 3 or 6 months postoperation in both the repaired and noninjured legs (all P Conclusions Differences in microcirculatory characteristics and better rehabilitation outcomes were observed in the legs with an Achilles repair that underwent the early vibration intervention.

Purpose: Graft remodeling in anterior cruciate ligament reconstruction (ACLR) demonstrates three distinct phases: necrosis, proliferation and ligamentization. Biological enhancement involves modulating these processes, but the cellular activities related to extracellular matrix remodeling have not been investigated. We hypothesized that changes in matrix metalloproteinases (MMPs) 1 and 13 expression are involved in the transition of proliferation phase to ligamentization phase of graft remodeling. Materials and methods: Thirty-three rats underwent ACLR. Tendon grafts were harvested at week 1 (necrosis), 2 (proliferation), or 12 (ligamentization) post-operation for histological examination (n = 3), or for isolation of graft-derived cells (n = 8) for flow cytometry, proliferation assay, cell invasion assay, measurement of gene expression related to matrix remodeling (Col1A1, Col3A1, MMP1, tissue inhibitor of marix metalloproteinase 1 (TIMP1), and MMP13) and total MMP activities. Results: Increased cellularity in tendon graft was contributed by active cell proliferation and migration at week 2 post-operation, while decreased cellularity were paralleled by increased apoptosis at week 12. All genes measured (Col1A1, Col3A1, MMP1, TIMP1, and MMP13) increased significantly in week 2 cells compared to week 1 cells. MMP1 expression subsided at week 12, while MMP13 expression kept increasing till 12 weeks post-operation. Total MMP activities was 3-fold higher in cultured graft-derived cells from week 2 as compared to cells from week 12. Two distinct processes of graft remodeling were identified, characterized by increased MMP1 expression with cell proliferation and increased MMP13 expression with cell apoptosis. Conclusions: Unfavorable matrix remodeling during the proliferation phase is found with increased MMP1, while remodeling leading to ligamentization is associated with increased MMP13 expression.

Tendinopathy includes cases with chronic tendon pain and spontaneous tendon ruptures, which is putatively resulted from failed tendon healing. Overuse is a major risk factor of tendinopathy, which can impose mechanical and oxidative stress to tendons. Previous studies investigated the influences of mechanical stress, but the direct impact of oxidative stress on tendon healing remains unclear. We hypothesized that imposed oxidative stress can impair tendon healing and lead to tendinopathic changes. Thirty-nine rats were operated for patellar tendon window injury. From weeks 3-5 post-operation, the rats received three weekly subcutaneous injections of saline, 50 or 500 μM H2 O2 (n = 13) over patellar tendon. Gait analysis for pain assessment and 3D ultrasound imaging for detection of tendinopathic changes were performed at pre-injury and 6-week post-operation. At week 6, knee specimens were harvested for histology or tensile mechanical test. Elastic modulus of the healing patellar tendons was significantly lower in 50 μM but not 500 μM H2 O2 group, while ultimate mechanical stress was not significantly different across groups. Similarly, only the 50 μM H2 O2 group exhibited pain-associated gait asymmetry. Significant tendon swelling with increased tendon volume was observed in the 50 μM H2 O2 group. There were hypoechogenic changes in the tendon wound, but there was no significant difference in percentage vascularity. H2 O2 impaired tendon healing and elicited tendinopathic changes, with respect to pain and structural abnormalities. Oxidative stress plays a role in the failed tendon healing of tendinopathies, and H2 O2 -induced failed tendon healing may serve as a good animal model to study tendinopathy. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3268-3274, 2018.

Background/Objective: Impingement syndromes are a common cause of shoulder pain in overhead athletes. Anterior internal impingement is a recently suggested mechanism for activity-related pain of the shoulder. Impingement syndromes were initially described to occur due to repetitive or excessive contact between the rotator cuff and other structures in the shoulder. Methods: This is a retrospective, clinical case study reporting 54 consecutive cases of anterior internal impingement in overhead athletes, of which 28 (51.2%) cases were of rugby players. All had undergone physiotherapy without relief of the symptoms. Of 54, there were 45 male and 9 female patients with an average age of 27 years (range, 17–51). The mean duration from injury to surgery was 40.7 weeks (range, 5–364). Of the 54 patients, 29 (53.7%) were full-time professional and 25 (46.3%) were semiprofessional or recreational athletes. The players associated the onset of pain occurred following an injury in 29/54 cases (53.4%), whereas in the remaining 25 cases (46.2%), a gradual onset of symptoms was described. All 54 patients could demonstrate a “functional impingement sign” in positioning their arm and provoke pain. Result: On examination, the examiner could reproduce the same pain in 38/54 (70.3%) patients only. Of the 54 patients, “SLAP tests” including O’Brien’s test, Palm up test, and compression rotation test were positive in shoulders of 39 (72.2 %) patients, Jobe’s test in 27 (50%), Gerber’s lift off test in 6 (11%), and Hawkin’s test in 6 (11%) patients. During arthroscopic assessment, impinging flap tears were found in 44 (81.4%) patients from the SLAP, whereas undersurface rotator cuff flap tears were found in 24 (44.4%), flap tears from the anterior or inferior labrum were found in 16 (29.6%), and distal subscapularis flap tears were found in 10 (18.5%) patients. Only in 12/54 patients (22.2%) was an isolated pathology found, in all cases SLAP tears. Treatment included vaporisation and excision of the impinging flaps. In 15/54 (27.7%) patients, repair of an unstable SLAP tear was undertaken using absorbable suture anchors and fibre wires. All athletes returned to their previous activity level within 17.2 weeks (range, 6–36) from surgery and were discharged when they claimed that they were symptom free. Conclusion: This series of anterior internal impingement, which we believe is the largest in the literature to date, demonstrates the value of an to assess and successfully treat overhead athletes with anterior impingement syndrome.

There are currently no studies that determine the total burden that tendinopathy places on patients and society. A systematic search was conducted to understand the impact of tendinopathy. It demonstrated that the current prevalence is underestimated, particularly in active populations, such as athletes and workers. Search results demonstrate that due to the high prevalence, impact on patients' daily lives and the economic impact due to work-loss, treatments are significantly higher than currently observed. A well-accepted definition by medical professionals and the public will improve documentation and increase awareness, in order to better tackle the disease burden.

Background/PurposeTo compare the neuromechanical characteristics and subjective outcomes for knees of patients with a cruciate ligament tear and reconstruction with those for knees of controls at three time intervals, and to determine correlations between the characteristics and subjective outcomes.MethodsTen participants with a cruciate ligament tear and at least a 12-week conservative treatment prior to ligament reconstruction were prospectively measured prior to and 3 months and 6 months after surgery. Ten healthy individuals were recruited as controls. Questionnaire surveys regarding the injured knee were conducted, as were bilateral measurements of root mean square electromyography (EMG), the rate of EMG rise, the median frequency in the vastus medialis of the quadriceps muscles and antagonist coactivation from the semitendinosus muscle, and force capacities, including peak torque, rate of force development, and total works of the knee extension. Correlations between the EMG variables (of the vastus medialis and semitendinosus) and the force capacities, and between the EMG variables and the knee injury and osteoarthritis outcome scores (KOOS), and between force capacities and the KOOS were assessed in the participants with a ligament reconstruction.ResultsPre- and postoperative results of EMG variable and force capacities were lower in both knees of the experimental group participants than in the control group participants (all p

Controlled laboratory study.To measure and compare patellar tendon stiffness and microcirculation in college tennis players and nonathletic students when performing eccentric knee extension exercises that do and do not reduce tendon stiffness.Previous studies suggest that tendon microcirculation response during exercises may vary based on the tendon's plastic properties. Methods The study included 3 groups of college-age male students: tennis players who performed 4 sets of either 40 (n = 12) or 80 (n = 13) repetitions of eccentric knee extension exercise and nonathletic students (n = 14) who performed 4 sets of 40 repetitions. Tendon stiffness was measured before and after exercise completion. Changes in total hemoglobin and oxygen saturation (OSat) were analyzed while performing the 4 sets. Comparisons were made within and between the groups. The level of association between tendon microcirculation and stiffness reduction was assessed.The 2 groups (player/4 × 80 and student/4 × 40) exhibiting patellar tendon stiffness reductions (P.008) showed higher total hemoglobin and OSat levels, above the pre-exercise levels, in the fourth set compared to the first set of exercises (P.004). The tennis players who performed 4 sets of 40 repetitions exhibited higher OSat levels in the fourth set than in the first set (P = .004) but had no reduction in tendon stiffness. Changes in OSat levels in the fourth set were correlated with patellar tendon stiffness reductions (r = -0.381, P = .02).We conclude that there was increased patellar tendon microcirculation after performing knee extension eccentric exercises that resulted in a reduction in tendon stiffness.

Acute knee (tibiofemoral joint) dislocation is a serious knee injury, although population-based numbers and incidence rates of knee dislocation with or without concomitant vascular injury are unknown.The study covered the whole adult population of 4 million persons (aged ≥ 18 years) in Finland during the 11-year period from January 1, 1998, to December 31, 2011. Data on hospitalization caused by acute knee dislocations and concomitant vascular injuries requiring operative treatment were obtained from the nationwide National Hospital Discharge Registry.During the 14-year study period, a total of 837 patients with knee dislocation diagnosis were hospitalized in Finland. The highest incidence rates in men were in persons aged 18 years to 29 years (incidence, 29 per 1 million person-years in 2011), and the incidence decreased by age, while in women, this incidence was rather similar in all age groups. The most common injury mechanism of knee dislocation was low-energy fall at the same level (46%). The median length of hospital stay was 2 days (range, 1-109 days). In 107 cases (13%), knee dislocation required immediate open (69 cases) or closed (38 cases) reduction in the operating room. Popliteal artery injury requiring acute surgical intervention was found in 13 patients (1.6%), and amputation at the level above the tibiofemoral joint was performed for one patient (0.1%).This is the first study describing the population-based incidence of acute knee dislocation. Men aged 18 years to 29 years had the highest incidence rates. Half of the injuries were low-energy trauma. Popliteal artery injury requiring surgical intervention was a rare concomitant injury, but when present, the injury required immediate surgical repair to avoid dramatic consequences.Nationwide epidemiologic study, level I.

Summary Graft healing in anterior cruciate ligament (ACL) reconstruction is often slow and compromised. There are numerous treatment strategies targeting at the biological healing process in ACL reconstruction. Most of these treatments attempt to promote graft incorporation at the tendon to bone interface, although the intra-articular mid substance would be more problematic. As intraoperative injection of vitamin C has been reported to be able to promote tendon healing, we speculate that vitamin C supplementation may also work for graft healing enhancement in ACL reconstruction. The purpose of this study is to formulate a vitamin C-supplemented saline for intraoperative irrigation, in order to promote biological healing in ACL reconstruction. The study hypothesis was tested using 114 rats. During ACL reconstruction, the knee joint of the rats were irrigated with either normal saline, or saline supplemented with 3 mg/mL, 10 mg/mL, or 30 mg/mL vitamin C. Inflammatory response was measured by serum C-reactive protein enzyme-linked immunosorbent assay at Day 1, Day 4, and Day 7 postoperation. Functional recovery was evaluated by gait analysis at preinjury, and Week 4 and Week 6 postoperation. Knee samples were harvested at Week 6 postoperation for anterior–posterior (A–P) knee laxity test and graft pull-out test. Histology was performed at Day 1, Day 4, Day 7, and Day 42 for scoring. Vitamin C supplementation at all doses significantly reduced serum C-reactive protein level as compared to saline control at Day 1 ( p = 0.029) postoperation. At 6 weeks postoperation, ACL reconstruction with 3 mg/mL vitamin C irrigation led to a better restoration of A–P knee laxity as compared to saline irrigation ( p = 0.032), whereas no positive effect was observed in the groups with 10 mg/mL and 30 mg/mL vitamin C irrigation. Vitamin C irrigation did not affect ultimate load of the graft complex. Histological analysis revealed that at Week 6 postoperation, graft deterioration was significantly reduced in 3 mg/mL and 10 mg/mL vitamin C groups, but no significant difference was observed in graft incorporation among different groups at Day 42 postoperation. Although no significant difference was detected in the gait parameters among experimental groups, increased percentage of rats with asymmetric walking gait (with limb idleness index > 1.3) was found in the groups of 10 mg/mL or 30 mg/mL vitamin C irrigation. The results showed that intraoperative supplementation of low dose (3 mg/mL) vitamin C effectively reduced graft deterioration and improved restoration of A–P knee laxity at 6 weeks postoperation, but higher doses of vitamin C irrigation may have side effects that lead to a higher chance of gait asymmetry. This study reveals the potential use of surgical irrigation saline as a delivery method for bioactive agents to promote healing, which might be a cost-effective and translatable approach for biological modulation for orthopaedic surgeries.

Objective. Tissue metaplasia is observed in both ossified failed healing animal model and clinical samples of tendinopathy. The Wnt signalling pathway plays a vital role in pathological calcification. We hypothesized that the Wnt signalling pathway might contribute to tissue metaplasia and failed healing in tendinopathy. This study aimed to examine the spatial-temporal expression of Wnt pathway mediators in an ossified failed tendon healing animal model and clinical samples of tendinopathy. The effect of Wnt3a on the osteogenic differentiation of tendon-derived stem cells (TDSCs) was also examined. Methods. Ossified failed tendon healing was induced by the injection of collagenase into the patellar tendon of rats. At various times the tendons were harvested for immunohistochemical staining of Wnt3a, b-catenin, Lrp5 and Tcf1. Patellar tendon samples were obtained from 13 patients with patellar tendinopathy (11 unossified and 2 ossified) and 10 controls. Immunohistochemical staining of Wnt3a, b-catenin, Lrp5 and Tcf1 was similarly performed. Rat patellar TDSCs were treated with Wnt3a. The osteogenic differentiation of TDSCs was examined by ALP activity, alizarin red S staining and mRNA expression of osteogenic markers. Results. There was increased expression of Wnt3a, b-catenin, Lrp5 and Tcf1 in the healing fibroblast-like cells, chondrocyte-like cells and ossified deposits in the animal model and in some clinical samples of tendinopathy. Wnt3a increased ALP activity, calcium nodule formation and expression of osteogenic markers in TDSCs. Conclusion. Activation of the Wnt signalling pathway and its effect on TDSCs might contribute to tissue metaplasia and failed healing in some cases of tendinopathy.

Background Functional deficits are found in ankles that have sustained an Achilles rupture. This study sought to evaluate and compare the morphomechanical characteristics of the medial gastrocnemius muscle in the legs of participants within six months of a unilateral Achilles repair to determine any correlations between those characteristics and objective outcomes and self-reported functional levels. Methods Fifteen participants were assessed via measurements of muscle morphologies (fascicle length, pennation angle, and muscle thickness) in a resting state, the mechanical properties of the proximal aponeurosis of the medial gastrocnemius muscle, the pennation angle during ramping maximal voluntary isometric contractions (MVIC), the heel raise test, and the Taiwan Chinese version of the Lower Extremity Functional Scale (LEFS-TC) questionnaire. Findings Compared with the non-injured legs, the repaired legs showed a lower muscle fascicle length (mean 4.4 vs. 5.0 cm) and thickness (1.7 vs. 1.9 cm), lower stiffness of the GM tendon and aponeurosis (174.1 vs. 375.6 N/mm), and a greater GM pennation angle (31.2 vs. 28.9°) during 90% MVIC (all p ≤ 0.05). Correlations were found between the morphomechanical results and maximal heel raise heights or the LEFS-TC score, and between the symmetry ratios of the fascicle lengths and the LEFS-TC score. Interpretation There are decreases in fascicle length, muscle thickness and mechanical properties in the medial gastrocnemius muscles of the participants within the first six months after an Achilles repair. These morphomechanical alterations demonstrate associations with functional levels in the lower extremities and indicated the need for early mobilization of the calf muscles after the repair.

Chronic tendinopathy refers to a broad spectrum of pathological conditions in tendons and their insertion, with symptoms including activity-related chronic pain. To study the pathogenesis and management strategies of chronic tendinopathy, studies in animal models are essential. The different animal models in the literature present advantages and limitations, and there is no consensus regarding the criteria of a universal tendinopathy animal model. Based on the review of literature and the discussion in the International Symposium on Ligaments and Tendons-X, we concluded that established clinical, histopathological and functional characteristics of human tendinopathy were all important and relevant criteria to be met, if possible, by animal models. As tendinopathy is a progressive, multifactorial tendon disorder affecting different anatomical structures, it may not be realistic to expect a single animal model to study all aspects of tendinopathy. Staging of tendinopathy over time and clearer definition of tendinopathies in relation to severity and type would enable realistic targets with any animal model. The existing animal models can be used for answering specific questions (horses for courses) but should not be used to conclude the general aspects of tendinopathy neither in animals nor in human.

Objective To assess if joint position sense (JPS) in the shoulder differed between un-injured rugby players, matched control subjects and previously injured rehabilitated rugby players. Design Mixed design. Setting University biomechanics laboratory. Participants 15 asymptomatic professional rugby union players, 15 previously injured professional rugby union players, 15 asymptomatic matched non-rugby playing controls had their JPS assessed. Main outcome measures JPS was assessed using two criterion angles in the 90° shoulder abduction position (45° and 80° external rotation). Results The study found a significant difference between groups in error score ( p =0.02). The testing angle also had a significant effect on error score ( p =0.002), with greater error scores occurring in the mid range position. Conclusion This study showed rugby players to have better JPS than controls, indicating JPS might not be related to injury risk. Poor JPS appears to be related to injury, players having sustained an injury have decreased JPS despite surgery and/or rehabilitation and returning to sport without incident.

To assess the effect of a simulated tackling task on shoulder joint position sense (JPS) in rugby players. The study also aimed to assess if differences in JPS occurred between mid range and end of range JPS, and if the tackling task had angle-specific effects on these values.Repeated measures.University human performance laboratory.Twenty-two asymptomatic professional rugby union players.JPS was assessed using two criterion angles in the 90 degrees shoulder abduction position (45 degrees and 80 degrees external rotation) prior to and following a simulated tackling task.Prior to the tackling task JPS (absolute error scores) was worse at the 45 degrees than 80 degrees criterion angle (p0.05). Following the tackling task absolute error scores were significantly increased at the 80 degrees angle (p0.001), with no significant change at the 45 degrees angle (p0.05), and no significant difference was present for error scores between angles (p=0.74).This study found JPS to be significantly reduced following a fatiguing task. But this change was only true for the end of range position, with JPS in the mid range not changing. If the mechanoreceptors are unable to accurately report shoulder position in the outer range (stretch) position due to repetitive tackling, then there is a potential for the anterior structures to become stressed before any compensatory muscle contraction can take place. These results highlight the presence of sensorimotor system deficits following repeated tackling. These deficits are proposed to contribute to overuse injuries and micro-instability of the glenohumeral joint which may be related to the increasing rate of shoulder injuries in rugby.

A protocol has been developed to obtain two-dimensional kinematic shoe data of football players in their training environment through high-speed video analysis. Such kinematic data can provide an understanding of how to better replicate the boundary conditions of football movements when simulated using mechanical traction and penetration test devices. As part of a pilot study, 11 youth academy players from a Premiership football club performed football-specific movements which were filmed at 1000 frames s-1. The protocol required minimal set-up time and the area of the pitch to be filmed could be positioned in any part of the playing area, causing low disruption to the players. This aimed to ensure that the movements performed were representative of those carried out during competitive play. Results in this study are concerned with the kinematics of the shoe during contact with the ground for movements identified to be important in terms of injury risk and loss of performance (slipping). Shoe velocities and orientations were measured for subjects wearing shoes of different stud types (traditional round studs versus contemporary bladed studs) on two surfaces (artificial turf, in-filled with rubber and sand, versus a natural surface). All the parameters measured from the relatively small population of subjects had high variances and therefore few significant effects of studs and surface could be found. The data does however provide insight into the appropriate boundary conditions to be used in mechanical test devices. For example, in the forefoot push-off movement it can be seen that test devices should measure the traction forces when the shoe first starts to move, as this is when the player would lose performance, as opposed to the maximum traction which can occur after significant displacement of the shoe through the surface. Analysis of the orientation and velocity path of the studs just before contact with the ground shows that the studs could be aligned to enhance their penetration into the surface and optimise the traction properties of the studs. In order to determine the orientation and velocity of the shoes at crucial phases in movements force-plate data obtained in the laboratory should be utilised in future studies.

Myocarditis is a disease entity of permanent actuality and of special concern in the sports setting. This is because the probability of complications or sequelae increases if exercise is imposed. Myocarditis may pass unrecognized by the sufferer or be easily overlooked by the physician, especially in athletes, where electrocardiographic changes often exist normally. Furthermore, although the immune system of the conditioned individual may be more efficient than that of the sedentary individual, very strenuous and frequently repeated or long-lasting exercise may cause immunosuppression and an increased susceptibility to respiratory tract infections (RTI). Several causative agents of RTI can give rise to myocarditis as well. The true incidence of proven infectious myocarditis in society is unknown. Histopathologically defined myocarditis (lymphocytic myocarditis), on the other hand, has been found in about 1% of unselected routine autopsies. In general, the long-term prognosis in myocarditis is favorable but exercise stress may cause long-term sequelae or sudden death. It is thus essential to refrain from strenuous exercise during RTI.

We recently presented a pilot study using an instrumented staple system for measuring in vivo local deformation on tibia. Methodological development has now proceeded in vitro. Consecutively, we performed 1. a sheep bone micrometer study, 2. a sheep bone four-point bending test and 3. a pig bone four-point and three-point bending test. This was done in order to secure a standardized application of the staple, to analyze the interaction of the bone and the staple and to secure calibration and the reliability of the system to be used in vivo. With reference to the above studies: 1. There was a linear relationship (r = 0.998) between the applied deformation of the bone and the measured deformation of the staple. ICC values ranged from 0.866 to 0.997. 2. An excellent intra-test reliability as well as linearity between staple measures and surface strain on the bone was observed (r = 0.998). 3. The slope of regression lines (k) was min 7.2 and max 9.4. The results from this test are used for calibration of the instrumented staple. Great variations were found between tension and compression measurements. However, within each test the SD was negligible. We suggest that the instrumented staple system may be calibrated in vitro and validly used for in vivo measurement of local bone deformation.

Growth factors potentially promote tendon healing. Understanding the right time to administer growth factors and the dosage of growth factors are prerequisites for designing effective cytokine therapy. We investigated the supplementation-time dependence of the effects of platelet-derived growth factor isoform B at various dosages on tendon healing, and the temporal responsiveness of healing tendon toward platelet-derived growth factor. Platelet-derived growth factor isoform B at various dosages (0, 10, 100, or 1000 ng) was delivered into the gap wound of rat patellar tendons via microsyringe injection on Day 3 or Day 7 after injury. Tendon specimens were harvested on Day 14 for measurement of cell proliferation, pyridinoline content, and mechanical properties. We found increased proliferative response only when the growth factor was supplemented on Day 3 after injury, whereas supplementation on Day 7 resulted in greater peak load, cross-sectional area, and pyridinoline content. The ultimate stress did not change. Our findings suggest supplementation of platelet-derived growth factor isoform B at Day 7 benefits the mechanical properties and maturation of healing tendons. We also found platelet-derived growth factor receptor beta expressing cells at the remodeling site as much as 6 months after injury, suggesting healing tendon also may be responsive to long-term delivery of platelet-derived growth factor.

This review discusses the so frequent dilemma for a sports physician or orthopaedic surgeon to stand in front of a professional soccer or rugby player with a knee injury, showing clear clinical signs of a meniscus tear or possibly chondral injury, but with an magnetic resonance imaging (MRI) which has been reported as normal. When arthroscopy finally is undertaken after a lot of discussion and delay caused by the reportedly normal MRI, the clinical suspicion is verified. The opposite situation may of course also occur. A clinician usually refers to MRI when the clinical diagnosis is unclear. However, among professional clubs in the UK the referral to a tertiary specialist is in many cases accompanied with an already undertaken MRI. In this review, we demonstrate several illustrative cases, where MRI has led to unnecessary management delays. The review focuses on meniscus and focal cartilage injuries. We suggest a range of possible solutions, which may improve the situation. There are several controversies to be addressed. First, detailed communication between the clinician and radiologist are often hampered by formal procedures. A referral is sent to the Radiology Department and a radiographer will perform a routine MRI protocol. The referral question may not always point to the correct injury, and is depending on the experience of the clinician. Usually, the radiologist is not present during scanning and instead puts together a protocol and subsequently reports on the images without having seen the injured player. Secondly, the use of different routine protocols for investigation of different structures is often not known in detail by the clinician. Thirdly, there is often a lack of standardized reporting of exact location, size and severity of focal cartilage injury in relation to the patients sporting demands. Furthermore, the quality of healed cartilage in a treated focal defect is of course of vital interest for allowing return to sport. Last but not least, inability to verify dynamic instabilities and structural behaviour during movement of the injured knee decreases the clinical value of MRI when compared with arthroscopy for a number of common sport injuries of the knee.

Corticosteroid injection is commonly used to treat tendon injuries but is often associated with tendon rupture and impaired tendon healing. The effects of dexamethasone on tenocytes have been studied in vitro but only using high concentrations of dexamethasone in monolayer cultures of tenocytes over short periods of time. We have therefore investigated the effects of physiological and pharmacological concentrations of dexamethasone on monolayer cultures of tenocytes over extended time periods. We have also used fibroblastic-colony forming unit cultures to examine the effects of dexamethasone on a progenitor cell population located in tendons. Culturing tenocytes in the presence of dexamethasone for a period of 24 days resulted in a concentration-related decrease in cell number and collagen synthesis as compared to control cultures. This effect was time dependent with cell number in both dexamethasone-treated and control cultures leveling off after 14 days with the control cultures reaching higher cell densities. In contrast in control cultures, collagen accumulation continued to increase until week 4, whereas in the presence of dexamethasone, this tended to level off after 14 days. To study the role of progenitor cell recruitment, the effects of dexamethasone were investigated using the fibroblastic-colony forming unit assay. Treatment with dexamethasone at concentrations of 0.1 nM to 10 microM leads to a progressive reduction in mean colony size as compared to control cultures. Colony number remained constant at concentrations below 10 nM but fell progressively at concentrations above this. In conclusion, dexamethasone reduces both cell number and collagen synthesis in tenocyte cultures in a concentration-dependent manner by both direct effects on tenocyte proliferation and collagen accumulation, and also by modulating the recruitment of tendon progenitor cells.

We studied the expression of procollagen type I, matrix metalloproteinase 1 (MMP1) and tissue inhibitor of metalloproteinase 1 (TIMP-1) by immunohistochemistry in human patellar tendinosis tissues and healthy patellar tendons. In situ gelatin zymography was used to detect collagenolytic activities. The productions of MMP1, TIMP1 and gelatinolytic activities were compared in cell cultures from tendinosis samples and controls. Tendinosis tissues and cultures showed an increase in the expression level of MMP1 and a decrease in that of TIMP1, a condition favoring collagen degradation. Gelatinolytic activities in tendinosis tissues and cultures were elevated. Collagenolysis is a striking feature in patellar tendinosis.

Patellar tendinosis is characterized by longstanding localized and activity-related pain, swelling and tenderness on palpation, and characteristic features on magnetic resonance imaging and ultrasonography and during surgical excision. Histologic examination of tendinosis tissues shows disrupted collagen matrix, increased cellularity, and increased proteoglycan stainability, but lack of inflammatory cell infiltration despite the clinical signs resembling inflammation. Disturbances in inflammatory response may be associated with the development of tendinosis. Expression of cyclooxygenase-2 and transforming growth factor-beta1 were detected in tendinosis, and the in vitro production of prostaglandin E2 by tendinosis and healthy tendon fibroblast cultures also was observed. Eleven patients with patellar tendinosis and 12 control subjects with healthy patellar tendons, but deficient anterior cruciate ligaments, were included in the current study. The percentages of immunopositive cells in tendinosis samples for cyclooxygenase-2 and transforming growth factor-beta1 were 66.75 and 56.40, respectively, which were significantly higher than those of the control subjects (25.15 and 23.06 respectively). Tendinosis fibroblast culture also produced more prostaglandin E2 and active transforming growth factor-beta1. These findings indicate the involvement of prostaglandins and cytokines that may explain the clinical symptoms and nonhealing features of tendinosis.

Background: Population-based incidence rates and trends of acute Achilles tendon ruptures are not known. It is also not known whether recent high-quality randomized controlled trials not favoring surgery have had an effect on treatment protocols. Purpose: To assess the incidence of acute Achilles tendon ruptures in Sweden and to examine the trends in surgical treatment. Study Design: Descriptive epidemiology study. Methods: We conducted a nationwide registry-based study including all adult (≥18 years of age) inpatient and outpatient hospital visits because of an acute Achilles tendon rupture in Sweden between 2001 and 2012. Results: We identified a total of 27,702 patients (21,979 men, 79%) with acute Achilles tendon ruptures between 2001 and 2012. In 2001, the sex-specific incidence of acute Achilles tendon ruptures was 47.0 (per 100,000 person-years) in men and 12.0 in women. In 2012, the corresponding values were 55.2 in men and 14.7 in women, with an increase of 17% in men and 22% in women. The proportion of surgically treated patients declined from 43% in 2001 to 28% in 2012 in men and from 34% in 2001 to 22% in 2012 in women. Conclusion: The incidence of acute Achilles tendon ruptures in Sweden is increasing. The most probable reason for this increase is the rise in the number of older adults participating in high-demand sports. The proportion of surgically treated patients is decreasing most likely because of recent high-quality randomized controlled trials and their meta-analyses supporting similar results between surgical and nonsurgical approaches.

One of the few serious drawbacks associated with running is overuse injuries such as stress fractures of the tibia, which cause local pain and swelling, often resulting in a temporary cessation of training. Whereas some runners rarely become injured, others experience recurrent injuries even during fairly short periods of time. The aim of the present study was to compare selected personality traits in a group of runners who had sustained a previous tibial stress fracture (n=17), with a matched group of runners (n=17) who had never experienced stress fractures. The results indicated that the injured runners, especially the women, scored higher than the non-injured runners did on inventories measuring both the Type A behavior pattern and exercise dependency. Since motivation, ambitiousness, and competitiveness are integral parts of these inventories, high scoring individuals might be part of a high-risk population for running injuries, the more so if the individual also feels dependent on regular running for managing stress related mood states, which was the case particularly for the injured women in the present study. However, the somewhat limited number of runners who had had a confirmatory scintigram, which was a criterion for inclusion in the study, warrants a cautious interpretation of the results. The findings nevertheless suggest that in order to prevent recurrent injuries, health education professionals and clinicians ought to focus on conveying the importance of detecting precursors of injury, and the subsequent steps which should be taken to avoid developing a serious injury.

One of the most challenging problems in muscular skeletal trauma is the limited capacity of regeneration of the damaged skeletal muscle fibers after injury and the inevitable replacement by fast growing fibrous tissue compromising function. To date, there is no effective therapeutic measure available in clinical practice. In the present study, red skeletal muscle aqueous extract has been prepared from female adult rats. This muscle extract could strikingly trigger the proliferation and differentiation of myoblasts whose progeny subsequently fuse to preexisting partially damaged muscle fibers to repair the damaged muscle fibers or to form new myotubes to replace the completely damaged muscle fibers during the process of muscle healing and regeneration in vivo. The active myogenic components are probably polypeptides since trypsin or heat treatment could abolish their activity in myogenesis.

Elite athletics requires maximum effort by the pursuer, exposing the tendons, ligaments and muscles, including the heart muscle, to intense and frequent mechanical and metabolic demands, which may increase the susceptibility to, and severity of, infections in these tissues. Furthermore, intense and frequent exercise with insufficient resting periods can compromise the immune system. Muscles and tendons are more vulnerable to overuse injuries in the recovery period following various infections. Although the etiology and pathogenesis of a substantial proportion of cases of tendinitis and tendinosis are still largely unknown, gram-positive cocci prevail as the most common etiologies in soft tissue infections. The recent identification of binding sites of staphylococci to intercellular tissue matrix components have opened up the possibility of selectively blocking such binding by prior vaccination. New molecular biological methods, enabling the identification of slow-growing bacteria that are difficult to culture, including Bartonella and Rickettsia, have created the possibility of studying the potential role also of such organisms in soft tissue conditions, including myocarditis. Acute myocarditis remains the most frequent form of myocarditis, commonly emerging in the course of an acute respiratory infection. Since myocarditis episodes are frequently subclinical and self-healing, athletes (and others) should generally be recommended rest during infections, especially during the early phase of the infection.

Alterations of the patellofemoral (PF) contact pressure and area were assessed using pressure-sensitive film after the removal of the central third of patellar tendon (PT) with healing over time in twelve dogs. The contralateral knee served as control. Histological sections were prepared for descriptive evaluation. No alterations in PT strain, PF contact pressure and area were measured immediately after the removal of the central third of PT compared with that before its removal. Compared with contralateral control, the healing of the donor PF induced a significantly increased PF contact area but not PF contact pressure in the specimens harvested at 6, 12, and 18 months after operation. Increased PF contact area indicated a proximal shift of the PF joint contact during flexion, which was associated with an increased strain of the healing PT under loading. The healing PT became hypertrophic compared with control, but the differences in the cross-sectional area were reduced over time. Histologically, a poorly organized extracellular matrix was observed at 6 months, with a progressive improvement in collagen fiber alignment up to 18 months postoperatively. The results of this study suggest that the removal of the central third of PT does not immediately change PF contact pressure and areas. However, remodeling of the healing tendon may cause an elongated PT, resulting in an increase in PF contact area under a given quadriceps force by knee extension.

During the period 1979-92, 16 (15 men and one woman) sudden unexpected cardiac deaths occurred among young Swedish orienteers. This finding indicated a sharp increase in the death rate of orienteers, and necropsy demonstrated that myocarditis was a common histopathological finding. Therefore, an extensive non-invasive cardiac investigation was performed. A total of 59 male elite orienteers (mean age 23 years) and 36 cross-country skiers and middle-distance runners (mean age 22 years), serving as controls, were examined by both echocardiography at rest and radionuclide ventriculography at rest and during exercise. Wall motion abnormalities were found in eight orienteers using echocardiography. The purpose of this study was to examine whether the group of orienteers with wall motion abnormalities found using echocardiography had a smaller increase in ejection fraction from rest to exercise using radionuclide ventriculography than the rest of the orienteers and the controls, indicating an aggravation of the wall motion abnormalities during exercise. There were no significant differences in the ejection fraction at rest between the groups. In the orienteers with wall motion abnormalities (group 1), 62% (five out of eight) had less than a 0.05 unit increase in left ventricular ejection fraction compared with 27% (14 out of 51) of the remaining orienteers (group 2) and 19% (7 out of 36) of the controls (group 3). A comparison of athletes in group 1 with those in groups 2 and 3 combined revealed a statistically significant difference (P < 0.05). The divergent response in left ventricular ejection fraction during exercise suggests an aggravation of the wall motion abnormalities with exercise. Both the echocardiographic and the radionuclide ventriculographic findings indicate that the orienteers in group 1 had concealed left ventricular damage.

The purpose of this study was to analyse objective modalities of ankle joint function after an acute ankle sprain and to see whether treatment with an air-cushioned ankle brace could enhance the restoration of function compared with a traditionally used compression bandage. The study included 73 consecutive patients between 15 and 55 years of age with an acute grade II or III ankle sprain, who sought medical care within 24 h of the time of injury. Patients with recurrent sprain were excluded. The patients were allocated at random to treatment with compression bandage or an air-cushioned ankle brace (Air-Stirrup, Aircast). The regimen included early motion and weight-bearing in both groups. The patients were examined initially within 24 h, after 3-5 days, 2, 4 and 10 weeks after the injury by the following tests: clinical examination including range of motion, recording of postural sway by stabilometry, joint position sense test, isokinetic eversion-inversion muscle torques and figure-of-eight running. A decreased active range of motion in eversion-inversion was observed during the entire follow-up period. Increased postural sway was registered when standing on the injured foot up to 4 weeks after the injury, as were a deficit in evertor muscle peak torque and an evertor-invertor muscle imbalance compared with the uninjured side. Women demonstrated a greater impairment in postural sway than men. A longer curve running time with the injured ankle at the outside of the curve was noted at the 10-week follow-up. With the exception of running in a figure of eight, these measures were not influenced by treatment with a semi-rigid ankle brace. The methods used in the present study are well suited for further studies of objective modalities of ankle joint function, with the possible exception of the joint position sense test.

Local bone deformation was registered at two predominant injury sites for tibial stress fractures in a healthy female volunteer. Two instrumented strain gauge staples were inserted under local anesthesia to the anterior middiaphysis (AM) and to the posteromedial part of the distal tibia (PD). Calibration and reliability of the instrumented staple system have previously been demonstrated in vitro. Concomitant ground reaction forces were registered with a Kistler force plate. Studying peak values, it was shown that during a voluntary 30-cm forward jump, PD deformation was greater during forefoot landing (2700–4200 microstrain) than during a heel strike landing (1200–1900 microstrain) and also compared with the concomitant AM deformation under both above testing conditions (1300–1900 microstrain). The stance phase during walking resulted in PD deformation of 950 microstrain, whereas the concomitant AM deformation was 334 microstrain. The greatest AM deformation (mean, 2128 microstrain) was registered during ground contact after a voluntary vertical drop from a height of 45 cm, concomitant with a PD deformation of 436 microstrain. These data are the first to show different local deformations at various sites of the tibia in vivo. The PD deformation was larger than previously noted from other parts of the tibia, whereas the middiaphysis data are consistent with other reports. The results may support the clinical assumption of different etiologies for stress fractures at these predominant sites.

Objectives: the primary objective was to compare 4 imaging sequences (T1-weighted, T2-weighted, proton density, and T1-weighted with gadolinium contrast agent enhancement) with regard to intratendinous signal abnormality in patients with achillodynia. the secondary objective was to relate the images to the clinical symptoms and histopathological findings Material and Methods: Twenty patients (16 men, 4 women, median age 40 years) with chronic achillodynia participated in the study. the symptoms prohibited activity and clinical examination revealed swelling and tenderness 1.5–6 cm proximal to the Achilles tendon insertion. of the 20 patients: 5 had bilateral achillodynia, 4 had had previous contralateral Achilles tendon disorder, and 11 had never had symptoms in the contralateral tendon region. These 11 tendons served as controls for comparison MR imaging was performed on a superconductive 1.5 T unit. Both Achilles tendons were examined (n=40) at the same time, and multiple sagittal and transversal images were obtained. the corresponding sections on these images were visually graded according to both extension and level of MR signal intensity. Tissue was obtained for microscopic examination from the most symptomatic side in all patients (n=20) Results: T1-weighted images following gadolinium contrast medium enhancement proved to be the best method by which to visualize intratendinous signal abnormality. This sequence revealed signal abnormality in 24/25 symptomatic tendons and in 1/11 control tendons ( p>0.001). Histopathological examination showed an increased noncollagenous extracellular matrix and altered fiber structure in the lesions corresponding to the contrast-enhanced areas Conclusion: Gadolinium enhancement improved the imaging of intratendinous signal abnormality on T1-weighted images. There was a high level of extracellular glycosaminoglycans, which are highly-fixed negatively-charged macromolecules with extreme water-retaining capacity and which may have contributed to the enhancement by the gadolinium contrast agent

Fifty-eight patients suffering from achillodynia for a median of 12 months (range, 4–240 months) were analyzed using history, clinical findings, ultrasound findings, histopathology, and surgical outcome. Surgical criteria were daily pain or inability to perform sports activity and failure of nonoperative treatment. There were 34 men and 24 women, 31% (18 of 58 patients) of whom had no direct association with sports or vigorous physical activity. Ultrasonography was performed in all cases and showed low echogenous areas (N = 48), increased tendon diameter (N = 40), and/or peritendinous fluid (N = 11). Histopathological evaluation of tendon biopsies, obtained from regions showing pathology at surgery (N = 35), revealed altered fiber structure and arrangement, focal variations in cellularity, extracellular glycosaminoglycans, neovascularization, and/or hyalinization. In no case was inflammatory cell infiltration observed. At a median clinical follow-up of 25 months after surgery, symptoms were decreased in 86% of patients, and 76% had reached a higher activity level compared with the level before surgery. Complications occurred in 13% of operations.In conclusion, achillodynia is not always associated with excessive physical activity. Macroscopic pathologic tendons showed marked histopathologic changes, correlating well with ultrasound findings. Surgical treatment was beneficial in most cases, despite a relatively high complication rate. The etiology and reason for the lack of healing response to rest and nonoperative treatment are unclear.

Between 1979 and 1992, there were 16 known cases of sudden unexpected cardiac death among young Swedish orienteers, whose autopsies showed myocarditis to be a common finding. Therefore, 96 elite orienteers and 47 controls underwent echocardiography, showing left ventricular wall motion abnormalities in 9% of the orienteers compared with 4% in the controls.

Echocardiography was used to assess normal values in the right and left ventricular cavity and wall in 127 male elite endurance athletes. M-mode and two dimensional measurements of left ventricle and left and right atria were also obtained. All subjects were high-performance orienteers, cross-country skiers and middle-distance runners. They all had a normal electrocardiogram at rest and no echocardiographic evidence of heart disease. With the use of multiple right ventricular cross-sections and two-dimensional measurements, we found a significantly greater right ventricular inflow tract and right and left atrial measurements in endurance athletes compared with earlier studies of normal, active subjects. The right ventricular free wall was slightly thicker than reported in normal active subjects but the differences were small. Left ventricular diastolic diameter was consistent with previous reports of endurance athletes. Of the 127 subjects, 13% had left ventricular wall thickness above 13 mm but none of the athletes had wall thickness above 15 mm. These data suggest that cardiac enlargement occurs symmetrically in both right and left cavities, probably reflecting increased haemodynamic loading, a mechanism by which athletes sustain a high cardiac output during exercise.

Objective To identify posture types that exist in professional rugby players, and compare them with a population of non-overhead athletes in order to identify possible relationships towards the potential for shoulder injuries. Design Observational design Setting: Sports Medicine Clinic Participants: Convenience sample Methodology: Static assessment of posture was carried out in standing, active and passive range of glenohumeral motion, and isometric strength was carried out in accordance with previously recorded protocols. Interventions Nil Outcome Measures: Observational classification of posture, active and passive range of glenohumeral joint range of motion, isometric strength of selected muscle groups, selected muscle flexibility and Hawkins and Neer impingement tests. Results There was a significant difference on range of motion between the two groups (0.025–0.000), isometric middle (0.024–0.005), and lower trapezius (0.01–0.001). Conclusion: There were significant differences between strength and flexibility of muscles around the shoulder girdle between professional rugby players and a control group of professional non-overhead athletes.

Initial graft tensioning is important in anterior cruciate ligament reconstruction (ACLR), but its effect on graft healing is still not clear. Since all previous animal studies on graft tensioning used bone–patellar tendon–bone, this study aimed to investigate the effect of initial graft tensioning on ACLR using tendon graft. Fifty-five Sprague–Dawley rats underwent ACLR using flexor digitorum longus tendon graft. A constant force of 2 or 4 N was applied during graft fixation. At 0, 2, and 6 weeks, knee samples were harvested (n = 6) for static knee laxity test and graft pull-out test. Histological examination was performed at 2 and 6 weeks post-injury (n = 4). At time zero, knee laxity was restored by ACLR with 2 or 4 N tensioning as compared to ACL-deficient group (p

Purpose The pathogenesis of patellar tendinopathy remains unclear. Expression of BMP-2/-4/-7 was reported in an ossified failed tendon healing animal model of patellar tendinopathy. This study aimed to investigate the expression of these chondro-osteogenic BMPs in clinical samples of patellar tendinopathy. Methods Patellar tendon samples were collected from 16 consecutive patients with patellar tendinopathy and 16 consecutive controls undergoing anterior cruciate ligament reconstruction with bone-patellar tendon-bone autograft in the authors’ hospital after getting their consent. The expression of BMP-2/-4/-7 was examined in all samples using immunohistochemistry. Ossification observed in two tendinopathy samples was characterized by histology, alizarin red S staining, alcian blue staining, TRAP staining and immunohistochemical staining of Sox9, osteopontin (OPN) and osteocalcin (OCN). Results Regions of hypo- and hyper-cellularity and vascularity, with loss of crimp structure of collagen matrix, were observed in patellar tendinopathy samples. Round cells and in some cases, cells with typical chondrocyte phenotype were observed. For the ossified tendinopathy samples with positive alizarin red S staining, OPN-positive and Sox9positive chondrocyte-like cells in alcian blue-stained extracellular matrix, OCN-positive osteoblast-like cells and TRAP-positive multi-nucleated cells were observed around the ossified deposits. No expression of BMP-2/-4/-7 was observed in healthy patellar tendons. However, the expression of BMP-2/-4/-7 was observed in all patellar tendinopathy samples with or without ossification. Conclusions Clinical samples of patellar tendinopathy showed ectopic expression of BMP-2/-4/-7. This was not evident in control samples from healthy patellar tendons. Level of evidence Prognostic studies, Level III.

Our understanding of the pathogenesis of "tendinopathy" is based on fragmented evidences like pieces of a jigsaw puzzle. We propose a "failed healing theory" to knit these fragments together, which can explain previous observations. We also propose that albeit "overuse injury" and other insidious "micro trauma" may well be primary triggers of the process, "tendinopathy" is not an "overuse injury" per se. The typical clinical, histological and biochemical presentation relates to a localized chronic pain condition which may lead to tendon rupture, the latter attributed to mechanical weakness. Characterization of pathological "tendinotic" tissues revealed coexistence of collagenolytic injuries and an active healing process, focal hypervascularity and tissue metaplasia. These observations suggest a failed healing process as response to a triggering injury. The pathogenesis of tendinopathy can be described as a three stage process: injury, failed healing and clinical presentation. It is likely that some of these "initial injuries" heal well and we speculate that predisposing intrinsic or extrinsic factors may be involved. The injury stage involves a progressive collagenolytic tendon injury. The failed healing stage mainly refers to prolonged activation and failed resolution of the normal healing process. Finally, the matrix disturbances, increased focal vascularity and abnormal cytokine profiles contribute to the clinical presentations of chronic tendon pain or rupture. With this integrative pathogenesis theory, we can relate the known manifestations of tendinopathy and point to the "missing links". This model may guide future research on tendinopathy, until we could ultimately decipher the complete pathogenesis process and provide better treatments.

Background The study objective was to assess the influence of a SLAP lesion on onset of EMG activity in shoulder muscles during a front on rugby football tackle within professional rugby players. Methods Mixed cross-sectional study evaluating between and within group differences in EMG onset times. Testing was carried out within the physiotherapy department of a university sports medicine clinic. The test group consisted of 7 players with clinically diagnosed SLAP lesions, later verified on arthroscopy. The reference group consisted of 15 uninjured and full time professional rugby players from within the same playing squad. Controlled tackles were performed against a tackle dummy. Onset of EMG activity was assessed from surface EMG of Pectorialis Major, Biceps Brachii, Latissimus Dorsi, Serratus Anterior and Infraspinatus muscles relative to time of impact. Analysis of differences in activation timing between muscles and limbs (injured versus non-injured side and non injured side versus matched reference group). Results Serratus Anterior was activated prior to all other muscles in all (P = 0.001-0.03) subjects. In the SLAP injured shoulder Biceps was activated later than in the non-injured side. Onset times of all muscles of the non-injured shoulder in the injured player were consistently earlier compared with the reference group. Whereas, within the injured shoulder, all muscle activation timings were later than in the reference group. Conclusions This study shows that in shoulders with a SLAP lesion there is a trend towards delay in activation time of Biceps and other muscles with the exception of an associated earlier onset of activation of Serratus anterior, possibly due to a coping strategy to protect glenohumeral stability and thoraco-scapular stability. This trend was not statistically significant in all cases

In this study, patients were presented with a questionnaire-based survey about the consumption of analgesics and pain ratings up to the third postoperative day following elective hallux valgus surgery. The aim was to study the consumption of analgesics and to look for factors influencing the need for rescue analgesia. All patients were provided with take-home oral medication, with etoricoxib 120 mg once daily, paracetamol 1 to 4 g daily, and dextropropoxyphene 100 mg provided as add-on rescue analgesics in a stepwise fashion. Thirty-five of the 102 patients responding (response rate 91%) did not take any further analgesics during the entire 4-day follow-up period than the recommended coxib, 67 patients took at least 1 tablet of rescue analgesic, 41 took only paracetamol, and 26 patients (25%) took paracetamol plus at least 1 dextropropoxyphene. There was a significant association between the subjective experience of pain and consumption of analgesics. Female gender and low age were significantly associated with the consumption of analgesics. A stepwise approach based on etoricoxib, paracetamol, and a small number of opioid tablets seems to be a rational approach for take-home medication following a standardized hallux valgus surgery. Female gender and lower age comprise a group that warrants special atten group that warrants special attention.

Background Tendon and ligament injuries are common and costly in terms of surgery and rehabilitation. This might be improved by using tissue engineered constructs to accelerate the repair process; a method used successfully for skin wound healing and cartilage repair. Progress in this field has however been limited; possibly due to an over-simplistic choice of donor cell. For tissue engineering purposes it is often assumed that all tendon and ligament cells are similar despite their differing roles and biomechanics. To clarify this, we have characterised cells from various tendons and ligaments of human and rat origin in terms of proliferation, response to dexamethasone and cell surface marker expression. Methods Cells isolated from tendons by collagenase digestion were plated out in DMEM containing 10% fetal calf serum, penicillin/streptomycin and ultraglutamine. Cell number and collagen accumulation were by determined methylene blue and Sirius red staining respectively. Expression of cell surface markers was established by flow cytometry. Results In the CFU-f assay, human PT-derived cells produced more and bigger colonies suggesting the presence of more progenitor cells with a higher proliferative capacity. Dexamethasone had no effect on colony number in ACL or PT cells but 10 nM dexamethasone increased colony size in ACL cultures whereas higher concentrations decreased colony size in both ACL and PT cultures. In secondary subcultures, dexamethasone had no significant effect on PT cultures whereas a stimulation was seen at low concentrations in the ACL cultures and an inhibition at higher concentrations. Collagen accumulation was inhibited with increasing doses in both ACL and PT cultures. This differential response was also seen in rat-derived cells with similar differences being seen between Achilles, Patellar and tail tendon cells. Cell surface marker expression was also source dependent; CD90 was expressed at higher levels by PT cells and in both humans and rats whereas D7fib was expressed at lower levels by PT cells in humans. Conclusion These data show that tendon & ligament cells from different sources possess intrinsic differences in terms of their growth, dexamethasone responsiveness and cell surface marker expression. This suggests that for tissue engineering purposes the cell source must be carefully considered to maximise their efficacy.

Objective To investigate if the increased proteoglycans in patellar tendinopathy involves a qualitative change in the types of proteoglycans. Design This is an observational study based on the biochemical analysis of proteoglycans. Setting : University Teaching Hospital. Patients Patellar tendon samples from 12 patients with patellar tendinopathy and 12 healthy controls were collected and proteoglycans were extracted for biochemical analyses. All patients fulfilled the diagnostic criteria of having patellar tendinopathy with well-defined clinical features, more than 6 months of insufficient nonoperative treatment including physiotherapeutic modalities, and verification by ultrasound or magnetic resonance imaging. Twelve control subjects, 10 men and 2 women with an average age of 31 years (range 16 to 38 years), represented patients with anterior cruciate ligament deficiency who were operated on using the healthy patellar tendon as an autograft. The control subjects had no previous history or clinical signs of patellar tendon injury. Interventions The independent variable is the presence of pathological conditions of patellar tendinopathy. Main outcome measurements The dependent variables include the electromobility of proteoglycans, staining intensity of proteoglycan core proteins, and the tissue content of glycosaminoglycan disaccharides. Results The results indicated that the increased proteoglycans in pathological tissues also exhibited qualitative changes as compared to those in healthy patellar tendons. Dermatan monosulfates were significantly increased in the proteoglycans extracted from the pathological tissues of patellar tendinopathy. Conclusions Our results indicate that proteoglycans deposited in the pathological tissues of patellar tendinopathy were oversulfated as compared to healthy tendons, which may represent a new pathological attribute for the understanding of chronic pain in patellar tendinopathy.