John P. Slavotinek

Clinical risk factors for hamstring muscle strain injury: a prospective study with correlation of injury by magnetic resonance imaging

Objective—To prospectively establish risk factors for hamstring muscle strain injury using magnetic resonance imaging (MRI) to define the diagnosis of posterior thigh injury. Method—In a prospective cohort study using two elite Australian Rules football clubs, the anthropometric characteristics and past clinical history of 114 athletes were recorded. Players were followed throughout the subsequent season, with posterior thigh injuries being documented. Hamstring intramuscular hyperintensity on T2 weighted MRI was required to meet our criteria for a definite hamstring injury. Statistical associations were sought between anthropometric and previous clinical characteristics and hamstring muscle injury. Results—MRI in 32 players showed either hamstring injury (n = 26) or normal scans (n = 6). An association existed between a hamstring injury and each of the following: increasing age, being aboriginal, past history of an injury to the posterior thigh or knee or osteitis pubis (all p<0.05). These factors were still significant when players with a past history of posterior thigh injury (n = 26) were excluded. Previous back injury was associated with a posterior thigh injury that looked normal on MRI scan, but not with an MRI detected hamstring injury. Conclusions—Hamstring injuries are common in Australian football, and previous posterior thigh injury is a significant risk factor. Other factors, such as increasing age, being of aboriginal descent, or having a past history of knee injury or osteitis pubis, increase the risk of hamstring strain independently of previous posterior thigh injury. However, as the numbers in this study are small, further research is needed before definitive statements can be made.

Diagnostic and Prognostic Value of Clinical Findings in 83 Athletes with Posterior Thigh Injury Comparison of Clinical Findings with Magnetic Resonance Imaging Documentation of Hamstring Muscle Strain

Background Little is known about the clinical features of posterior thigh injuries and their contribution to accurate diagnosis and prognostic assessment of hamstring muscle strain injury. Hypotheses The clinical features of posterior thigh injury can be used to diagnose hamstring muscle strain and to predict duration of absence from competition. Study Design Prospective clinical study. Methods For two playing seasons, the clinical features of posterior thigh injury, timing of injury, and playing days lost were recorded for Australian Rules football players. Magnetic resonance imaging was used to confirm hamstring muscle injury. Results Posterior thigh injuries associated with pain and tenderness were recorded for 83 players, with magnetic resonance imaging confirming hamstring injury in 68 (82%). Most of the hamstring injuries were sudden onset (62; 91%) and occurred after a significant warm-up period (57; 84%). Of the patients whose injuries were sudden onset and occurred after the warm-up period (N = 59), 57 (97%) had hamstring muscle strain detected on magnetic resonance imaging. Hamstring muscle injury confirmed by magnetic resonance imaging was associated with a longer absence from competition (mean, 27 days) than injuries where no hamstring injury was detected (mean, 16 days). Conclusions The clinical features of hamstring injury typically include sudden onset, pain, and tenderness, although exceptions do occur. Muscle fatigue may be important in the pathogenesis of hamstring injury.

Incidence of pubic bone marrow oedema in Australian rules football players: relation to groin pain

Objectives—To examine the relation between the clinical features of groin pain and groin magnetic resonance imaging (MRI) appearances in a group largely comprising elite Australian Rules football players. The incidence of bone marrow oedema and other MRI findings in the pubic symphysis region was noted. The relation between a past history of groin pain and these other MRI findings was also examined. Method—In a prospective study, 116 male subjects (89 footballers, 17 umpires, 10 sedentary men) were examined before history taking and groin MRI. The clinical history was not known to the examiner (GMV) and radiologists (JPS, GTF). Clinical evidence of groin pain and examination findings were correlated with the presence of increased signal intensity within the pubic bone marrow. A past history of groin pain was correlated with the presence of other MRI findings such as cyst formation, fluid signal within the pubic symphysis disc, and irregularity of the pubic symphysis. Results—Fifty two athletes (47 footballers, five umpires) had clinical features of groin pain with pubic symphysis and/or superior pubic ramus tenderness. A high incidence of increased signal intensity (77%) within the pubic bone marrow was identified in this group. There was an association between this group of athletes and the MRI finding of increased signal intensity (p<0.01). There was also an association between a past history of groin pain and the presence of other MRI findings (p<0.01). Conclusions—Athletes with groin pain and tenderness of the pubic symphysis and/or superior pubic ramus have clinical features consistent with the diagnosis of osteitis pubis. The increased signal intensity seen on MRI is due to pubic bone marrow oedema. An association exists between the clinical features of osteitis pubis and the MRI finding of pubic bone marrow oedema. A high incidence of pubic bone marrow oedema was also noted. Degenerative features visualised by MRI, such as subchondral cyst formation, were associated with a past history of groin pain. A stress injury to the pubic bone is the most likely explanation for these MRI findings and may be the cause of the clinical entity osteitis pubis.

Change in liver size and fat content after treatment with Optifast Very Low Calorie Diet

Background: Laparoscopic adjustable gastric banding (LAGB) requires surgical access to the gastroesophageal junction, which may be compromised by the enlarged, fatty liver that is frequently encountered in the obese. Liver size appears reduced and surgical access improved following preoperative weight loss with Optifast® Very Low Calorie Diet (VLCD). The aim of this study was to assess the effects of 6 weeks Optifast® VLCD on liver volume and fat content. Methods: 18 morbidly obese subjects underwent magnetic resonance imaging and spectroscopy to measure liver size and fat content before and after intensive treatment with Optifast® VLCD for 6 weeks. Results: All subjects completing 6 weeks Optifast® VLCD lost weight. Body weight and BMI (median [interquartile range]) reduced from 119.7 [111.9-131.3] kg and 44 [40-51] kg/m2 respectively, to 110.6 [98.0124.5] kg and 40 [36-47] kg/m2, P<0.001. Median excess weight loss (EWL) was 15.1 [9.6-21.1]%. Baseline liver volume and fat content were related (r=0.633, P=0.005). After 6 weeks Optifast® VLCD, there was a 14.7% reduction in mean liver volume (P<0.001) and a 43% reduction in mean liver fat (P=0.016). The change in liver volume was predicted by the change in the liver fat (r = 0.610, P=0.012). Conclusion: This study has demonstrated that a 6week diet with Optifast® VLCD results in significant related reductions in liver size and liver fat content. This suggests that the reduction in liver volume is due to loss of fat. The reduction in liver fat and volume likely accounts for the perceived improved operability in patients undergoing LAGB.

The effect of sports specific training on reducing the incidence of hamstring injuries in professional Australian Rules football players

Objectives: To assess in a single team of Australian Rules football players the effect of a specific intervention program on the incidence and consequence of hamstring muscle strain injuries. Method: A prospective study was performed with a single team being followed for four playing seasons for hamstring injury. Magnetic resonance imaging was used to confirm the diagnosis of hamstring muscle injury. After two playing seasons an intervention program was implemented with the number of athletes with hamstring injury, competition days missed, and incidence of hamstring match injuries per 1000 h of playing time being compared pre- and post-intervention. The intervention program involved stretching whilst fatigued, sport specific training drills, and an emphasis on increasing the amount of high intensity anaerobic interval training. Results: In the seasons prior to the intervention, nine and 11 athletes sustained hamstring injury compared to two and four following intervention. Competition days missed reduced from 31 and 38 to 5 and 16 following intervention and match incidence decreased from 4.7 to 1.3 per 1000 h of playing time. A beneficial effect was demonstrated with a smaller number of players having hamstring injuries (p = 0.05), a lower number of competition games missed being recorded (p<0.001), and a decrease in hamstring strain incidence per 1000 h of playing time (p = 0.01) following the intervention program. Conclusions: Increasing the amount of anaerobic interval training, stretching whilst the muscle is fatigued, and implementing sport specific training drills resulted in a significant reduction in the number and consequences of hamstring muscle strain injuries.

Hip joint range of motion reduction in sports-related chronic groin injury diagnosed as pubic bone stress injury

Traumatic osteitis pubis is a non-specific entity that relates to chronic groin injury and has recently been described as being akin to a pubic bone stress injury. It is uncertain whether or not reduction of hip joint range of motion occurs in traumatic osteitis pubis. The purpose of this study was to establish whether there is a reduction of hip range of motion in athletes who have chronic groin injury diagnosed as pubic bone stress injury. A case-control study was performed whereby 89 Australian Rules footballers underwent, with clinical history unknown, clinical and MRI examination of the groin region. Clinical criteria (pain with tenderness) and MR-criteria (pubic bone marrow oedema) were used for diagnosis of pubic bone stress injury. End-range internal and external rotation hip motion was measured using a goniometer. Athletes with and without symptoms were compared, as were athletes with current symptoms with athletes who had recovered from their groin pain episode. Chronic groin injury was diagnosed in 47 athletes with 37 having pubic bone stress injury. Thirteen athletes had previous groin injury. A reduction of internal and external hip range of motion was demonstrated in athletes with pubic bone stress injury (p < 0.05) and in athletes who had current symptoms compared to those who had recovered from their groin pain episode (p < 0.05). A reduction in hip range of motion was evident in athletes with chronic groin injury diagnosed as pubic bone stress injury. There may be a role for increasing hip range of motion in rehabilitation.

Description of pain provocation tests used for the diagnosis of sports‐related chronic groin pain: relationship of tests to defined clinical (pain and tenderness) and MRI (pubic bone marrow oedema) criteria

The clinical assessment of groin pain in athletes is difficult, with the lack of specific clinical tests being in part responsible. Three pain provocation tests used in the diagnosis of chronic groin pain are described and their relationship to defined clinical and MRI criteria has been assessed.

Groin Pain in Footballers The Association Between Preseason Clinical and Pubic Bone Magnetic Resonance Imaging Findings and Athlete Outcome

Background Groin pain and tenderness are common in athletes from a variety of codes of football, but little attention has been directed to the influence of magnetic resonance imaging and such clinical findings on athlete participation. Hypothesis Preseason groin pain, tenderness, and magnetic resonance imaging findings such as pubic bone marrow edema are associated with restricted training capacity and missed games. Study Design Cohort study; Level of evidence, 2. Methods Fifty-two Australian footballers in the national competition were recruited. Preseason groin pain and focal tenderness were recorded, and magnetic resonance imaging of the groin was performed within 1 week of examination. Training restriction and games missed owing to groin pain were documented during the subsequent season. Results Magnetic resonance imaging showed pubic bone marrow edema in 19 of 52 (37%) footballers and linear parasymphyseal T2 hyperintensity in 16 of 52 (31%) footballers. Groin pain restricted training during the season in 22 of 52 (42%) footballers, and 9 of 52 (17%) footballers missed at least 1 game. Preseason pain (P =. 0004), pubic bone tenderness (P =. 02), and linear parasymphyseal T2 hyperintensity (P =. 01) were associated with restricted training capacity during the subsequent season. Preseason groin pain (P =. 03) was associated with missed games, but magnetic resonance imaging findings were not. Conclusion Preseason pubic bone marrow edema, groin pain, and linear parasymphyseal T2 hyperintensity were associated with training restriction, but only preseason groin pain was associated with missed games.

Two graph theory based methods for identifying the pectoral muscle in mammograms

Two image segmentation methods based on graph theory are used in conjunction with active contours to segment the pectoral muscle in screening mammograms. One method is based on adaptive pyramids (AP) and the other is based on minimum spanning trees (MST). The algorithms are tested on a public data set of mammograms and results are compared with previously reported methods. In 80% of the images, the boundary of the segmented regions has average error less than 2mm. In 82 of 84 images, the boundary of the pectoral muscle found by the AP algorithm has average error less than 5mm.

Outcome of Conservative Management of Athletic Chronic Groin Injury Diagnosed as Pubic Bone Stress Injury

Background Little data exist on the results of treatment for sports-related chronic groin injury. Hypothesis Sports-related chronic groin injury treated with a conservative (rest) program results in a satisfactory outcome. Study Design Case series; Level of evidence, 4. Methods Professional Australian male football players, at the end of the playing season, had their groin injury diagnosed using specific clinical and magnetic resonance imaging (MRI) criteria. Those assessed as having a non-hip-related cause for their chronic groin injury were treated principally by 12 weeks of complete rest from active weightbearing activities. Response to treatment was assessed at different stages of rehabilitation by recording the number of athletes who had returned to playing football and the number of athletes without symptoms. Results Twenty-seven athletes were considered to have chronic groin injury. Clinical and MRI (pubic bone marrow edema N = 26 [96%]), hyperintense line N = 25 [93%]) criteria suggested a pubic bone stress injury as diagnosis for the chronic groin injury. Eighty-nine percent of athletes returned to sport in the subsequent playing season, with 100% having returned by the second playing season after diagnosis. Forty-one percent of the athletes were without symptoms at the commencement of the following playing season, rising to 67% by the end of that playing season. Conclusions Conservative management of athletic chronic groin injury resulted in an excellent outcome when assessed by the return to sport criterion. However, the results were only satisfactory if the criterion of ongoing symptoms after treatment was used. More research is needed to compare the efficacy of all treatments that are used in this troublesome condition.