Paramagnetic contrast medium in high-level athletes with lower limb muscle injuries: can it make the return to sport safer reducing the recurrence rate?

PURPOSE: The aim is to investigate whether contrast medium can improve accuracy in the assessment of healing muscle injury in high-level professional athletes. MATERIALS AND METHODS: Our series is a retrospective study including the records of 22 players (mean age 28 ± 5 SD) with lower limbs muscle injuries type 3a (Mueller-Wohlfarth). All athletes received two MRIs: the day after the injury and before resuming heavy effort activities. Contrast medium uptake was measured in the second MRI by comparing the mean enhancement at the lesion site (ME) with that of the healthy contralateral muscle (HM). The result is a percentage referred to as muscular contrast index (MC index). The difference between the mean MC index value between athletes with and without re-injury was assessed with both the Mann-Whitney and the Kruskal-Wallis test. RESULTS: Twenty-nine muscle injuries matched the inclusion criteria. The mean MC index values, adjusted for the variable of time elapsed between the last contrast examination and return to the field, were significantly different in the two study groups (p < .001). CONCLUSION: The contrast medium in the follow-up of muscle injuries may be useful in determining the degree of scar stability in a healing injury. Injuries with a high MC index were found to be 'unstable', with a higher rate of recurrence than those with a low MC index. Resumption of competitive activity after achieving not only clinical resolution but also a satisfactory MC index value may increase the safety of return to the field and reduce the recurrence rate.

Seasonal variation of bone turnover markers in top-level female skiers.

Different levels of weight-bearing activities imply different levels of anabolic effects on skeletal tissue and this can be assessed by measuring biochemical markers reflecting bone metabolism. With this study we wanted to determine how the serum levels of bone turnover markers change during different phases of annual training in elite female skiers. Fourteen top-level Caucasian athletes, from the Italian Women's Alpine Ski Team (slalom and giant slalom), were tested at the end of the relative rest period (T1), the pre-competitive season (T2) and the competitive season (T3). Serum levels of bone-specific alkaline phosphatase (BAP) and tartrate-resistant acid phosphatase (TRAP5b) activities and of osteocalcin (OC), and crosslaps (the carboxyterminal crosslinked telopeptide of type I collagen--ß-CTx), were assayed together with the determination of 25(OH)D levels. The formation markers, BAP and OC and the resorption marker TRAP5b significantly increased from T2 to T3, while crosslaps showed no significant changes. The peculiar trends of bone formation markers correlated one to each other at T2 versus T3, and this was probably linked to the highly demanding period of competitions when, in athletes performing weight-bearing exercise, bone is more stimulated by mechanical forces. 25(OH)D levels, instead, changed from T1 to T2 and from T1 to T3 and its trend do not show any correlation with that of bone markers. In conclusion, we found that both the bone formation markers and TRAP5b, marker of resorption, are significantly increased from the pre-competitive season to the competitive season.

Reticulocyte profile in top-level alpine skiers during four consecutive competitive seasons.

The role of reticulocytes (Ret) in sports medicine became clear when the count of immature erythrocytes was introduced in protocols used for anti-doping purposes. Because specific research regarding seasonal variations in Ret is lacking, we assessed Ret (and [Hb]) in top-level male and female skiers during four consecutive competitive seasons. A difference (P < 0.05) between males and females was found for [Hb] and Ret values: [Hb] was lower and Ret was higher in females. The difference was maintained across all four competitive seasons. Marked within-subject differences in [Hb], Ret and immature reticulocyte fraction values were noted; the within-subject variability was greater than the between-subject variability in both genders. For instance, a difference for Ret was consistently shown between first and second blood drawings, i.e. between basal value, before the start of training and competition, and the value at middle of season, when training workload was at highest level. Unlike Ret%, the analysis of variance showed significant changes in [Hb] values across competitive seasons for both genders. Comparison between consecutive seasons (e.g., 2005-2006 vs. 2006-2007) showed significant differences for both parameters. The behaviour of [Hb] and Ret during the various seasons was parallel in females, whereas a discrepancy existed in males. In general, inter-individual variability is quite high, thus, Ret and [Hb] modifications should be referred only to the single athlete. We confirm the validity of the use of Ret counts for anti-doping purposes.

Evaluation of muscle tears in professional athletes using diffusion-weighted imaging and apparent diffusion coefficient: preliminary results.

PURPOSE: Many studies have evaluated the role of DWI in musculoskeletal diseases but less is known on muscle tears. Especially for professional athletes, muscle injuries are responsible for large time lost. The aim of this study was to investigate on potential relationship between the muscle tear degree and the diffusion characteristics. METHODS: In this retrospective study, patients signed a comprehensive consent form according to Good Clinical Practice guidelines before proceeding with all examinations. It satisfied all the requirements of the Declaration of Helsinki and the Italian national law for the protection of personal data. We have analyzed 38 professional athletes (36 males; mean age±standard deviation 27±8 years) with a muscle tear. They were 26 football and 12 athletics players, with clinically suspected injuries of the lower limbs muscles. All of patients underwent a 1.5-T MRI with standard protocol (STIR, TSE T2, SE T1, PD T2, PD fat sat T2) plus the DWI sequences with 0, 400 and 800 B-values (s/mm2). Per each B value, an experienced radiologist measured the signal intensity (SI, in arbitrary units [au]) using a region of interest (ROI) placed within the tear on DWI images. SI drop off at the third B value was calculated referred to the first B value. Similarly, ADC was measured using the ADC map in a small ROI within the tear. Bivariate associations were evaluated using the Student t test. Logistic regression was performed using the tear degree as dependent variable. Data were given as mean±standard deviation. RESULTS: According the Muller-Wohlfarth classification, the 38 muscle tears were classified in type 3a in 22/38 cases and 3b in 16/38 cases. At bivariate analysis, 3a-tears had a SI at the third B value (24±9 au) lower (P=0.003) than that of 3b-tears (34±9 au). Similarly, 3a-tears had a SI drop off (73±10%) lower (P=0.008) than that of 3b-tears (82±9%). ADC was not significantly associated to tear degree (P=0.093). At regression analysis, SI at the third B value was the only independent predictor of the tear degree (P=0.032), while the SI drop off was borderline significant (P=0.070). CONCLUSION: This preliminary data showed a positive correlation between the degree of muscle tears and the SI at the third B-value. Compared to 3a- tears, 3b-tears tend to show higher SI and a higher SI drop off.