To determine the 1-year self-reported incidence of overuse and traumatic sport injuries and risk factors for injuries in children participating in a summer sports camp representing seven different sports. 4363 children, 11 to 15 years old participating in a summer camp in seven different sports answered a questionnaire. Injury in this cross-sectional study was defined as a sport-related trauma or overload leading to pain and dysfunction preventing the person from participation in training or competition for at least 1 week. A number of risk factors for injury were investigated such as sex, age, number of hours spent on training in general, and on resistance training with weights. Nearly half [49%, 95% confidence interval (CI) 48–51%] of the participants had been injured as a result of participation in a sport during the preceding year, significantly more boys than girls (53%, 95% CI 50–55% vs 46%, 95% CI 43–48%; P < 0.001). Three factors contributed to increased incidence of sport injuries: age, sex, and resistance training with weights. Time spent on resistance training with weights was significantly associated with sport injuries in a logistic regression analysis. In children age 11 to 15 years, the risk of having a sport-related injury increased with age and occurred more often in boys than in girls. Weight training was the only modifiable risk factor that contributed to a significant increase in the incidence of sport injuries.

Background and Purposes The objectives of this study were to investigate the inter- and intraobserver agreement in the classification of distal radius fractures (DRFs) according to the AO and the Buttazzoni classification system, for the two different radiology modalities: conventional radiography (CR) and cone-beam computed tomography (CBCT). Furthermore, we aimed to explore whether the radiological modality used influences the choice of treatment. Patients and Methods Fifty consecutive patients with DRFs were included. The fractures were visualized by both CR and CBCT. All images were independently reviewed by five observers (three orthopaedic surgeons and two radiologists) and the fractures were classified according to the AO and the Buttazzoni classification. Agreement on fracture classification between CR and CBCT, interobserver agreement for all observers, and intraobserver agreement for a repeated assessment after 8 weeks were calculated. Treatment was suggested by the orthopaedic surgeons. Results The Buttazzoni classification showed higher interobserver agreement than the AO classification, but the agreement for the AO classification was increased using CBCT. The agreement between classification of fractures by CR and CBCT for each observer varied from fair to moderate. CBCT was superior for classification of dorsally comminute fractures using both the AO and the Buttazzoni system. In 38% ( n = 57) of the observations, the suggested treatment was changed when CBCT was used, both from less advanced to more advanced and vice versa. Conclusion The choice of radiological modality affects both the classification and the choice of treatment for DRFs and CR tends to underestimate the complexity of DRFs. Level of Evidence Level 1.

We have previously shown age- and time-dependent effects on brain activity in the primary somatosensory cortex (SI), in a functional magnetic resonance imaging (fMRI) study of patients with median nerve injury. Whereas fMRI measures the hemodynamic changes in response to increased neural activity, magnetoencephalography (MEG) offers a more concise way of examining the evoked response, with superior temporal resolution. We therefore wanted to combine these imaging techniques to gain additional knowledge of the plasticity processes in response to median nerve injury. Nine patients with median nerve trauma at the wrist were examined with MEG. The N1 and P1 responses at stimulation of the injured median nerve at the wrist were lower in amplitude compared to the healthy side (pamp;lt;.04). Ulnar nerve stimulation of the injured hand resulted in larger N1 amplitude (pamp;lt;.04). The amplitude and latency of the response did not correlate with the sensory discrimination ability. There was no correlation between N1 amplitude and size of cortical activation in fMRI. There was no significant difference in N1 latency between the injured and healthy median nerve. N1 latency correlated positively with age in both the median and ulnar nerve, and in both the injured and the healthy hand (pamp;lt;.02 or pamp;lt;.001). It is concluded that conduction failure in the injured segment of the median nerve decreases the amplitude of the MEG response. Disinhibition of neighboring cortical areas may explain the increased MEG response amplitude to ulnar nerve stimulation. This can be interpreted as a sign of brain plasticity.

Peripheral nerve injuries result in reorganization within the contralateral hemisphere. Furthermore, recent animal and human studies have suggested that the plastic changes in response to peripheral nerve injury also include several areas of the ipsilateral hemisphere. The objective of this study was to map the inter-hemispheric plasticity in response to median nerve injury, to investigate normal differences in contra- and ipsilateral activation, and to study the impact of event-related or blocked functional magnetic resonance imaging (fMRI) design on ipsilateral activation. Four patients with median nerve injury at the wrist (injured and epineurally sutured amp;gt;2 years earlier) and ten healthy volunteers were included. 3T fMRI was used to map the hemodynamic response to brain activity during tactile stimulation of the fingers, and a laterality index (LI) was calculated. Stimulation of Digits II-III of the injured hand resulted in a reduction in contralateral activation in the somatosensory area SI. Patients had a lower LI (0.21 +/- 0.15) compared to healthy controls (0.60 +/- 0.26) indicating greater ipsilateral activation of the primary somatosensory cortex. The spatial dispersion of the coordinates for areas SI and SII was larger in the ipsilateral than in the contralateral hemisphere in the healthy controls, and was increased in the contralateral hemisphere of the patients compared to the healthy controls. There was no difference in LI between the event-related and blocked paradigms. In conclusion, patients with median nerve injury have increased ipsilateral SI area activation, and spatially more dispersed contralateral SI activation during tactile stimulation of their injured hand. In normal subjects ipsilateral activation has larger spatial distribution than the contralateral. Previous findings in patients performed with the blocked fMRI paradigm were confirmed. The increase in ipsilateral SI activation may be due to an interhemispheric disinhibition associated with changes in the afferent signal inflow to the contralateral primary somatosensory cortex.

Purpose: Scaphoid fractures in patients and assessment of healing using PCD-CT have, as far as we know, not yet been studied. Therefore, the aim was to compare photon counting detector CT (PCD-CT) with energy integrating detector CT (EID-CT) in terms of fracture visibility and evaluation of fracture healing. Method: Eight patients with scaphoid fracture were examined with EID-CT and PCD-CT within the first week posttrauma, and with additional scans at 4, 6 and 8 weeks. Our clinical protocol for wrist examination with EID-CT was used (CTDIvol 3.1 +/- 0.1 mGy, UHR kernel Ur77). For PCD-CT matched radiation dose, reconstruction kernel Br89. Quantitative analyses of noise, CNR, trabecular and cortical sharpness, and bone volume fraction were conducted. Five radiologists evaluated the images for fracture visibility, fracture gap consolidation and image quality, and rated their confidence in the diagnosis. Results: The trabecular and cortical sharpness were superior in images obtained with PCD-CT compared with EIDCT. A successive reduction in trabecular bone volume fraction during the immobilized periods was found with both systems. Despite higher noise and lower CNR with PCD-CT, radiologists rated the image quality of PCD-CT as superior. The visibility of the fracture line within 1 -week post -trauma was rated higher with PCD-CT as was diagnostic confidence, but the subsequent assessments of fracture gap consolidation during healing process and the confidence in diagnosis were found equivalent between both systems. Conclusion: PCD-CT offers superior visibility of bone microstructure compared with EID-CT. The evaluation of fracture healing and confidence in diagnosis were rated equally with both systems, but the radiologists found primary fracture visibility and overall image quality superior with PCD-CT.

Background: Surgery with volar locking plate (VLP) for distal radius fractures (DRFs) has become dominant over percutaneous Kirschner wire (K-wire) (PKW) fixation. Not many studies have proved advantages of the VLP and the increasing dominance of the VLP is thus not derived from evidence of superiority but influenced by other factors.Methods: By retrospectively classifying 346 DRFs treated with either PKW or VLP fixation, according to the Buttazzoni classification system, we aimed to investigate the determining factors for choice of surgical method, and by review of the patients' medical records, the functional outcome, duration, and frequentness of the rehabilitation period were correlated to Buttazzoni type and surgical method.Results: The odds ratio of having volar plate fixation was negatively correlated to age and positively correlated to a higher Buttazzoni type. We found no clinically significant differences in the functional outcome for different Buttazzoni type of fractures within the VLP and PKW groups, respectively, nor between the 2 methods of surgery for any Buttazzoni type of fracture.Conclusion: Younger patients and fractures with higher grade of instability were more likely to be treated with VLP than PKW; however, neither fracture instability nor surgical method had any impact on functional outcome.

Introduction and aims: Accurate determination of skeletal muscle size is of great importance in multiple settings including resistance exercise, aging, disease, and disuse. Ultrasound (US) measurement of muscle thickness (MT) is a method of relatively high availability and low cost. The present study aims to evaluate a multisite ultrasonographic protocol for measurement of MT with respect to reproducibility and correlation to gold-standard measurements of muscle volume (MV) with magnetic resonance imaging (MRI) in children.Material and methods: 15 children completed the study (11 +/- 1 year, 41 +/- 8 kg, 137 +/- 35 cm). Following 20 min supine rest, two investigators performed US MT measurements of all four heads of the m. quadriceps femoris, at pre-determined sites. Subsequently, MRI scanning was performed and MV was estimated by manual contouring of individual muscle heads.Results: Ultrasound measurement of MT had an intra-rater reliability of ICC = 0.985-0.998 (CI 95% = 0.972-0.998) and inter-rater reliability of ICC = 0.868-0.964 (CI 95% = 0.637-0.983). The US examinations took less than 15 min, per investigator. Muscle thickness of all individual quadriceps muscles correlated significantly with their corresponding MV as measured by MRI (overall r = 0.789, p &lt; 0.001).Conclusion: The results of this study indicate that US measurement of MT using a multisite protocol is a competitive alternative to MRI scanning, especially with respect to availability and time consumption. Therefore, US MT could allow for wider clinical and scientific implementation.

Background and purpose - The incidence of Perthes disease as reported in the literature varies widely between and within countries. The etiology of the disease is still unknown. Both environmental and genetic factors have been suggested to play a part in either causing the disease or increasing the susceptibility of an individual. We determined the incidence of Perthes disease in Sweden and investigated possible relationships to parental socioeconomic status, ethnicity, marital status, mothers age when giving birth, parity, number of siblings, and smoking habits. Patients and methods - Six Swedish population-based registers were used, together covering all children born in Sweden from 1973 through 1993. Results - The incidence of Perthes disease in Sweden was 9.3 per 100,000 subjects. The ratio between boys and girls was 3.1:1. The educational level of the father and the mother of a child with Perthes disease was lower than in the controls. The incidence was lower when the fathers were in the highest income bracket (above the 90(th) percentile). A higher proportion of parents of Nordic lineage had children with Perthes disease than parental pairs with one or both who were not of such lineage. Interpretation - This study confirms that there is an association between the incidence of Perthes disease and the socioeconomic status of the parents.

In 2016, our primary modality for radiological examination of wrist trauma, was changed from radiography to cone-beam computed tomography (CBCT). This is a retrospective survey of carpal bone fractures detected by CBCT during 6 months in 2016/2017, compared with those found on conventional radiographs during 6 months in 2013/2014. The incidence of carpal fractures was three times higher during the CBCT period (92/100,000 per year) compared with the radiography period (29/100,000 per year) and the spectrum of anatomical locations was different between the two periods, with fractures of the lunate (n = 6), trapezium (n = 9), trapezoid (n = 4) and capitate (n = 1) detected by CBCT, in contrast to no fractures of these bones diagnosed during the 6 months radiography period. We suggest a more liberal use of CBCT for examination of wrist trauma considering the benefits of being able to give patients a correct primary diagnosis, treatment and prognosis.

Background

To ascertain or disprove a correlation between suboptimal birth characteristics, breech position at delivery and development of Perthes’ disease.

Methods

Study material was collected from nationwide registers regarding diagnoses, birth statistics and delivery data. As study population were included children with a diagnosis code for Perthes’ disease who were alive and living in Sweden at age 13. Children with missing birth statistics were excluded. All children with no Perthes’ disease diagnosis were used as control group. Both single and multiple logistical regression analyses were used to calculate OR for the included characteristics.

Results

Children in breech position had a higher risk for developing Perthes’ disease. Children with Perthes’ disease had also a higher probability of having been born pre-term, very pre-term or post-term. Lower than normal birth weight and a lower Apgar-score were also associated with Perthes’ disease.

Conclusions

There is a correlation between breech birth and development of Perthes’ disease. There is also correlation to suboptimal birth characteristics. Despite our findings this should not be used for screening of Perthes’ disease as the percentage of children who actually develop it is very low. Also, as of yet there is no possibility to diagnose Perthes’ disease before the presence of skeletal changes. Our findings could be important in finding the cause of Perthes’ disease and therefore developing better diagnostics, treatment and prevention.

Background Full-depth cartilage lesions do not heal spontaneously and may progress to osteoarthritis (OA). Treatment for these lesions is warranted when symptomatic. At younger age, biological treatment remains the gold standard, but treatment in the middle-aged patient remains a clinical challenge and focal metal implants have been proposed. We aim to present the subjective outcome at 2 years and the risk of reoperation for any reason at midterm after surgery with a novel customized implant for focal femoral chondral lesions in the knee. Methods In a prospective cohort study, 30 patients were included between January 2013 and December 2017 at 9 different clinics in Sweden. The primary outcome was subjective outcome measurements (Visual Analogue Scale [VAS], EuroQoL [EQ5D], Knee injury and Osteoarthritis Outcome Score [KOOS]) at a minimum of 2 years. The secondary outcome was reoperations for any reason during the follow-up period until December 2019 (mean of 55 months) studied retrospectively by analyzing medical records. Results The VAS, EQ5D, and all the KOOS subscales showed significant improvements from preoperatively to the 2-year follow-up. The VAS showed the greatest improvement at the early (3 months) postoperative stage (P &lt; 0.001). Five (7%) patients underwent reoperations and one of these was revised to hemiarthroplasty due to OA progression. No implant loosening was detected in any of the cases. Conclusions This customized resurfacing metal implant showed good safety and patient satisfaction. The risk of OA progression and implant loosening is low. Subjective function and pain improved significantly.

Introduction The ischaemic pain of acute compartment syndrome (ACS) can be difficult to discriminate from the pain linked to an associated fracture. Lacking objective measures, the decision to perform fasciotomy is based on clinical findings and performed at a low level of suspicion. Biomarkers of muscle cell damage may help to identify and monitor patients at risk, similar to current routines for patients with acute myocardial infarction. This study will test the hypothesis that biomarkers of muscle cell damage can predict ACS in patients with tibial fractures. Methods and analysis Patients aged 15-65 years who have suffered a tibial fracture will be included. Plasma (P)-myoglobin and P-creatine phosphokinase will be analysed at 6-hourly intervals after admission to the hospital (for 48 hours) and-if applicable-after surgical fixation or fasciotomy (for 24 hours). In addition, if ACS is suspected at any other point in time, blood samples will be collected at 6-hourly intervals. An independent expert panel will assess the study data and will classify those patients who had undergone fasciotomy into those with ACS and those without ACS. All primary comparisons will be perforated between fracture patients with and without ACS. The area under the receiver operator characteristics curves will be used to identify the success of the biomarkers in discriminating between fracture patients who develop ACS and those who do not. Logistic regression analyses will be used to assess the discriminative abilities of the biomarkers to predict ACS corrected for prespecified covariates. Ethics and dissemination The study has been approved by the Regional Ethical Review Boards in Linkoping (2017/514-31) and Helsinki/Uusimaa (HUS/2500/2000). The BioFACTS study will be reported in accordance with the Strengthening the Reporting of Observational Studies in Epidemiology recommendations.

Circulating microRNAs (miRNAs) have become increasingly popular biomarker candidates in various diseases. However, heparin-based anticoagulants might affect the detection of target miRNAs in blood samples during quantitative polymerase chain reaction (qPCR)-based analysis of miRNAs involving RNA extraction, cDNA synthesis and the polymerase catalyzed reaction. Because low-molecular-weight heparins (LMWH) are widely used in routine healthcare, we aimed to investigate whether a prophylactic dose of the LMWH tinzaparin influences qPCR-based quantification of circulating miRNAs. A total of 30 subjects were included: 16 fracture patients with tinzaparin treatment and 14 non-fracture controls without anticoagulation therapy. To control for the effect of tinzaparin on miRNA analysis an identical concentration of synthetic miRNAs was added to plasma, isolated RNA and prepared complementary DNA (cDNA) from all samples in both groups. No significant difference was observed for cDNA synthesis or qPCR when comparing tinzaparin-treated patients with untreated controls. Among the tinzaparin-treated patients, plasma levels of six endogenous miRNAs (hsa-let-7i-5p, hsa-miR-30e-5p, hsa-miR-222-3p, hsa-miR-1-3p, hsa-miR-133a-3p, hsa-miR-133b) were measured before and one to six hours after a subcutaneous injection of tinzaparin 4500IU. No significant effect was observed for any of the investigated miRNAs. A prophylactic dose of 4500IU tinzaparin does not seem to affect cDNA synthesis or qRT-PCR-based quantification of circulating miRNAs.

Background Hip and groin injuries are common in men’s professional football, but the time-trend of these injuries is not known.

Aim To investigate hip and groin injury rates, especially time-trends, in men’s professional football over 15 consecutive seasons.

Study design Prospective cohort study.

Setting Men’s professional football.

Methods 47 European teams were followed prospectively for a varying number of seasons between 2001/2002 and 2015/2016, totalling 268 team seasons. Time-loss injuries and individual player exposure during training and matches were recorded. Injury rate was defined as the number of injuries/1000 hours and injury burden as the number of lay-off days/1000 hours. Time-trends for total hip and groin injuries and adductor-related injury rates were analysed using Poisson regression, and injury burden was analysed using a negative binomial regression model.

Results Hip and groin injuries contributed 1812 out of 12 736 injuries (14%), with adductor-related injury as the most common of hip and groin injuries (n=1139, 63%). The rates of hip and groin injury and adductor-related injury were 1.0/1000 hours and 0.6/1000 hours, and these rates decreased significantly with on average 2% (Exp(b)=0.98, 95% CI 0.97 to 0.99, P=0.003) and 3% (Exp(b)=0.97, 95% CI 0.95 to 0.99, P<0.001) per season (year on year), respectively. The seasonal trend of hip and groin injury burden did not improve (Exp(b)=0.99, 95% CI 0.97 to 1.01, P=0.40).

Conclusions Hip and groin injuries constitute a considerable part of all time-loss injuries in men’s professional football. Although there was a promising slight decreasing trend in the rates of hip and groin injury (as a category) and adductor-related injury (as a specific diagnosis), the injury burden remained at a consistent level over the study period.

Background Fractures of the distal radius are the most common fractures of the upper extremity. The choice of surgical method has been debated and studies show that short-term differences, in favour of volar locking plates, are indistinguishable at 1 year follow-up. Few studies have investigated long-term outcomes beyond one year. The aim of this study was to investigate long-term (6-10 years) patient-reported outcomes after distal radius fracture surgery, and to determine how fracture pattern/complexity (Buttazzoni fracture type) affects the results. Methods 303 patients surgically treated for a distal radius fracture, from 2012-2016 were included. The questionnaires used were PRWE, Quick-DASH and EQ-5D. Previous studies have shown that fracture type influences the choice of surgical method and therefore fracture type was adjusted for in the statistical analysis. Results We found that patients treated with K-wires had significantly better Quick-DASH scores (p &lt;0.05) and a lower degree of pain (PRWE pain scale) (p &lt;0.05) than patients treated with volar locking plates. There was no difference between the two groups regarding the remaining outcome measures for any Buttazzoni type of fracture. Conclusion On the basis of these results, K-wires can be considered an equivalent option to locking plates because of equal or better long-term outcomes, lower costs, and shorter operation times.