Presence of bone marrow oedema in asymptomatic elite fast bowlers: Implications for management.

OBJECTIVES: 1) Quantify the intensity of bone marrow oedema (BMO) present in the lumbar vertebrae of asymptomatic elite adult fast bowlers; 2) relate the intensity of BMO to bowling workload and lumbar bone stress injury (LBSI), and; 3) evaluate the utility of MRI screening to reduce the risk of LBSI. METHODS: Thirty-eight elite Australian fast bowlers (21.6 ± 3.7 years) completed 48 screening MRI over 3 years. BMO intensity was quantified on MRI retrospectively. Standard practices for bowling workload monitoring and injury diagnosis were followed. RESULTS: Clinically significant BMO (signal intensity ratio ≥ 2.0) was observed in 22 (46%, 95% CI 31-61) screening MRI. These bowlers had a total of 77 (IQR 45-115) days off between seasons, compared to 66 (IQR 41-94) days off for bowlers with a BMO intensity less than 2.0 (p = 0.510). Fifteen bowlers received follow up MRI as part of individualised management based on their screening MRI, of which less than five went on to develop LBSI in the subsequent season. There was no difference in days or balls bowled in the 12 months following screening MRI between those who sustained LBSI and those who did not. CONCLUSIONS: BMO is common in asymptomatic bowlers. Identification of high-risk bowlers using screening MRI informs individualised management and may prevent progression to LBSI.

Radiological healing of lumbar spine stress fractures in elite cricket fast bowlers.

OBJECTIVES: Review magnetic resonance imaging (MRI) of elite adult fast bowlers with a history of lumbar spine stress fracture for evidence of bone healing. The findings will determine whether bone healing can occur in this population, and whether MRI may be used as a tool to assess bone healing and inform clinical decision making. DESIGN: Retrospective cohort. METHODS: Participants were elite Australian fast bowlers who sustained a lumbar spine stress fracture confirmed on MRI and had at least one subsequent MRI. Two radiologists independently reviewed all images. RESULTS: Thirty-one fractures from 20 male fast bowlers were reviewed. Median maximum fracture size was 6mm (range 2-25mm). Twenty-five fractures achieved bone healing, with a median 203 (IQR 141-301) days between the initial MRI (to confirm diagnosis) and the MRI when bone healing was observed. Fracture size and signal intensity of bone marrow oedema were positively associated with the number of days to the MRI when bone healing was observed (r2=0.245, p<0.001 and r2=0.292, p<0.001 respectively). Fractures which occurred at the same site as a previously united fracture took longer to heal than the first fracture (median 276 days to the MRI when bone healing was observed compared to 114 days for first fracture; p=0.036). CONCLUSIONS: Lumbar spine stress fractures in elite adult fast bowlers are capable of achieving complete bone healing, as demonstrated in the majority of bowlers in this study. Larger fractures, greater bone marrow oedema, and history of previous injury at the same site may require longer healing time which may be monitored with MRI.

Hand fractures and return to play in elite Australian cricketers.

INTRODUCTION: Hand fractures are one of the most common injuries sustained whilst playing cricket. Further research is required to inform future clinical management and risk-reduction strategies. METHODS: This retrospective cohort study reviewed all cases of hand fractures in elite Australian cricket players over a three-year period. Data included specific activity when injury occurred, location of injury, management (non-surgical or surgical) and days to return to play. RESULTS: Seventy (17%, 95% CI 14-21 of players; 43 male, 27 female) players sustained 90 hand fractures. Seventy-three (81%, 95% CI 72-89) fractures occurred whilst fielding the ball. Eighty-four (93%, 95% CI 86-97) fractures occurred to the 'exterior' bones of the hand: distal phalanx, middle phalanx, first and fifth rays. Thirteen (14%, 95% CI 9-23) fractures were managed with surgical internal fixation, of which 11 were to the phalanges, most commonly at the proximal phalanx (n = 5, 36% of all proximal phalanx fractures) or fifth ray middle and proximal phalanges (n = 5, 42% of all fifth ray phalangeal fractures). Fractures requiring surgical management typically had longer time injured (median 33 days, IQR 27-41) than fractures managed non-surgically (median 6 days, IQR 0-21) (p = 0.001). Total time to return to full unrestricted play was similar between surgical (49 days, IQR 45-52) and non-surgical (32 days, IQR 15-45) management (p = 0.197). CONCLUSIONS: Hand fractures sustained by elite male and female Australian cricket players were found to display a pattern of occurring to the 'exterior' bones of the hand. The results of this study may inform clinical decision making with respect to non-surgical or surgical management and anticipated return to play times. Further effort is needed to address risk reduction strategies including gloves and skill proficiency.

MRI Bone Marrow Edema Signal Intensity: A Reliable and Valid Measure of Lumbar Bone Stress Injury in Elite Junior Fast Bowlers.

STUDY DESIGN: Comparative reliability and prospective validity. OBJECTIVE: First, to evaluate the reliability of four methods of assessing magnetic resonance imaging (MRI) bone marrow edema (BMO) of the posterior vertebral arch of the lumbar vertebrae of elite junior fast bowlers. Second, to evaluate the validity of the most reliable method for the early detection of lumbar bone stress injury. SUMMARY OF BACKGROUND DATA: MRI has demonstrated utility in identifying BMO in lumbar vertebrae. Methods to grade the severity of BMO may provide valuable insight to inform clinical management, particularly in elite athletes where detection of early-stage bone stress may prevent progression to more severe and costly bone stress injury. METHODS: Sixty-five male elite junior fast bowlers had repeat MRI scans during a cricket season. A subset of 19 bowlers' images were reassessed by experienced musculoskeletal radiologists to determine intra- and inter-rater reliability. All images were aligned with independent medical records of lower back symptoms and diagnosed bone stress injuries to establish the relationship of BMO and lumbar bone stress injury. RESULTS: Clinical detection of abnormal BMO, whether the pars region of the vertebra was considered in its entirety or subdivided into regions, had fair-to-moderate inter-rater reliability, and fair-to-almost perfect intra-rater reliability. Measurement of BMO signal intensity using an imaging software tool had excellent intra-rater and inter-rater reliability (ICC = 0.848, 0.837). BMO signal intensity was positively associated with subsequent LBSI (P < 0.001), and differentiated between asymptomatic and symptomatic bowlers (P < 0.001). CONCLUSION: Measurement of BMO signal intensity using an imaging software tool proved a reliable and valid measure of the severity of lumbar bone stress injury in elite junior fast bowlers. LEVEL OF EVIDENCE: 2.

MRI bone marrow oedema precedes lumbar bone stress injury diagnosis in junior elite cricket fast bowlers.

OBJECTIVES: Lumbar bone stress injury ('bone stress injury') is common in junior fast bowlers. The repetitive loading of cricket fast bowling may cause bone marrow oedema (BMO), detectable on MRI, before the bowler suffers from symptomatic bone stress injury. We investigated the temporal relationship between BMO, bone stress injury, along with bowling workload correlates, in elite junior fast bowlers throughout a cricket season. METHODS: 65 junior fast bowlers were prospectively monitored for one 8-month cricket season. For research purposes, participants had up to six MRI scans at set times in the season; findings were withheld from them and their clinicians. Standard practices for bowling workload monitoring and injury diagnosis were followed. RESULTS: 15 (23%) participants developed bone stress injury during the study. All 15 of these participants had BMO detected on at least one of the preceding MRI scans, including the scan immediately prior to diagnosis. The risk of BMO progressing to bone stress injury during the season was greatest for participants with BMO present 2 weeks prior to the national championship tournament (period of high load) (RR=18.9, OR=44.8). Both bone stress injury and BMO were associated with bowling a higher percentage of days in training and having a shorter bowling break during the season. The number of balls bowled and acute-to-chronic workload were not associated with imaging abnormalities or injury. CONCLUSION: The presence of BMO on MRI in asymptomatic junior cricket fast bowlers confers a very high risk for bone stress injury. The risk may be managed by MRI screening and monitoring bowling frequency.