MRI of overuse injury in elite athletes

Asymptomatic Elite Adolescent Tennis Players' Signs of Tendinosis in Their Dominant Shoulder Compared With Their Nondominant Shoulder

CONTEXT

Tennis is an asymmetric overhead sport with specific muscle-activation patterns, especially eccentrically in the rotator cuff. Magnetic resonance imaging (MRI) findings in asymptomatic adolescent elite tennis players have not previously been reported.

OBJECTIVE

The first aim of the study was to describe MRI findings regarding adaptations or abnormalities, as well as muscle cross-sectional area (CSA), of the rotator cuff. The second aim of the study was to investigate the rotator cuff based on the interpretation of the MRI scans as normal versus abnormal, with the subdivision based on the grade of tendinosis, and its association with eccentric rotator cuff strength in the dominant arm (DA) of the asymptomatic elite adolescent tennis player.

SETTING

Testing environment at the radiology department of Medicinsk Röntgen AB.

PATIENTS OR OTHER PARTICIPANTS

Thirty-five asymptomatic elite tennis players (age = 17.4 ± 2.7 years) were selected based on ranking and exposure time.

INTERVENTION(S)

We assessed MRI scans and measured the CSA of the rotator cuff muscle. The non-DA (NDA) was used as a control. In addition, eccentric testing of the external rotators of the DA was performed with a handheld dynamometer.

RESULTS

The DA and NDA displayed different frequencies of infraspinatus tendinosis (grade 1 changes) (P < .05). Rotator cuff measurements revealed larger infraspinatus and teres minor CSA (P < .05) in the DA than in the NDA. Mean eccentric external-rotation strength in the DA stratified by normal tendon and tendinosis was not different between groups (P = .723).

CONCLUSIONS

Asymptomatic adolescent elite tennis players demonstrated infraspinatus tendinosis more frequently in the DA than in the NDA. Clinicians must recognize these tendon changes in order to modify conditioning and performance programs appropriately.

The foot in multistage ultra-marathon runners: experience in a cohort study of 22 participants of the Trans Europe Footrace Project with mobile MRI

OBJECTIVES

67 runners participated in the Trans Europe FootRace 2009 (TEFR09), a 4487 km (2789 mi) multistage ultra-marathon covering the south of Europe (Bari, Italy) to the North Cape. Reports on ultra-marathons are lacking, but the literature reports overuse injuries in athletes, especially to the Achilles tendon (AT), ankle or hind foot. Bone oedema may be related to exposure and is present in fatigue fractures. Therefore, the aim of this study was to determine prospectively if sustained maximal load during an ultra-marathon leads to damage to the foot.

DESIGN AND PARTICIPANTS

In a cohort study, repeated scanning of the 22 athletes participating in the study was performed before and during (approximately every 1000 km) the race. Using the obtained fat saturated inversion recovery sequence, two experienced readers blinded to the clinical data rated the images regarding foot lesions. Statistical analysis included regression analysis and computation of the inter-rater reliability.

SETTING

The TEFR09 course. MRI scanning was performed according to prearranged schedules for every participant, using a mobile 1.5 Tesla MRI unit on a trailer following the race.

PRIMARY OUTCOME MEASURES

MRI data such as AT diameter, bone or tendon lesions, subcutaneous, plantar fascia or intraosseous oedema.

RESULTS

The 22 study participants did not differ significantly from the total of the 67 TEFR09 runners regarding height, weight and age. The AT diameter increased significantly from 6.8 to 7.8 mm as did intraosseous signal, bone lesions and subcutaneous oedema. However, finishers differed only regarding plantar aponeurosis and subcutaneous oedema from participants aborting the TEFR09. Inter-rater reliability was 0.88-0.98.

CONCLUSION

Under the extreme stress of the TEFR09, an increase of the AT diameter as well as bone signal are thought to be adaptive since only subcutaneous oedema and plantar fascia oedema were related to abortion of the race.

TRIAL REGISTRATION NUMBER

University of Ulm, Germany Ethics Committee Number 78/08-UBB/se.