The Response of Hip Joint Cartilage to Exercise in Children: An MRI Study Using T2-Mapping

Asymptomatic female softball pitchers have altered hip morphology and cartilage composition

Few studies have explored hip morphology and cartilage composition in female athletes or the impact of asymmetric repetitive loading, such as occurs during softball pitching. The current cross-sectional study assessed bilateral bony hip morphology on computed tomography imaging in collegiate-level softball pitchers ('Pitch1', n = 25) and cross-country runners ('Run', n = 13). Magnetic resonance imaging was used to assess cartilage relaxation times in a second cohort of pitchers ('Pitch2', n = 10) and non-athletic controls ('Con', n = 4). Pitch1 had 52% greater maximum alpha angle than Run (p < 0.001) and were 21.3 (95% CI 2.4 to 192.0) times more likely to have an alpha angle ≥ 60° within at least one hip. Pitch2 had longer T2 relaxation times in the superior femoral cartilage of the drive leg (same side as the throwing arm) and stride leg than Con (all p < 0.02). The drive leg in Pitch2 had longer T1ρ and T2 relaxation times in the superior femoral cartilage compared to the stride leg (all p ≤ 0.03). Asymptomatic softball pitchers exhibit altered bony hip morphology and cartilage composition compared to cross-country runners and non-athletic controls, respectively. They also exhibit asymmetry in cartilage composition. Further studies with larger sample sizes are warranted and any potential long-term consequences of the changes in terms of symptom and osteoarthritis development requires investigation.

Are hip joint imaging findings associated with symptoms and early hip osteoarthritis features in elite male Australian Football League draftees?

1) describe intra-articular features (prevalence and severity) and bony hip morphology (prevalence and size) in elite male Australia Football League (AFL) draftees; 2) examine the relationship between bony hip morphology (cam and pincer morphology) and intra-articular features (cartilage defects and labral tears); and 3) examine the relationship between intra-articular features, bony hip morphology, and the Copenhagen Hip and Groin Outcome Score (HAGOS). Cross-sectional study. 58 male AFL draftees underwent 3-tesla hip MRI. Alpha angle determined cam morphology and acetabular depth defined pincer morphology. For each hip, intra-articular features were scored semi-quantitatively. All players completed the HAGOS to determine hip/groin symptoms and sports function. Logistic regression determined whether bony hip morphology was associated with labral tears and cartilage defects. Mann-Whitney U tests evaluated the difference in HAGOS subscale scores between football players with and without intra-articular features and bony hip morphology. Cam and pincer morphology were evident in 20% and 19% of hips, respectively. Nearly half of hips (41%) had a labral tear, with only 14% having a cartilage defect. Greater alpha angle was associated with the presence of labral tears (OR 1.14, 95%CI 1.07 to 1.21, p < 0.001) but not cartilage defects. Hip imaging findings were not associated with lower (worse) HAGOS scores. Hip joint imaging findings were common in elite male AFL draftees but not associated with worse pain, symptoms, or sport function. Cam morphology may contribute to the development of labral tears in male AFL draftees.

Cam morphology is associated with MRI-defined cartilage defects and labral tears: a case-control study of 237 young adult football players with and without hip and groin pain

Objective

Football players are at risk of developing hip osteoarthritis (OA). Cam morphology (present in almost two of every three football players) may explain this heightened risk, but there is limited research on its role in hip OA development in younger athletes. Knowledge of this relationship will advance our understanding of the aetiology of hip OA in football players. We aimed to study the relationship between cam morphology size and MRI-defined cartilage defects and labral tears, and if this relationship differs by symptomatic state in young adult football players.

Methods

For this case–control study, 182 (288 hips) symptomatic (hip and/or groin pain >6 months and positive flexion-adduction-internal-rotation (FADIR) test) and 55 (110 hips) pain-free football players (soccer or Australian football) underwent anteroposterior and Dunn 45° radiographs, and 3-Tesla MRI. Cam morphology size was defined using alpha angle, and cartilage defects and labral tears were scored semiquantitatively. Presence, location and score (severity) of cartilage defects and labral tears were determined. Each participant completed the International Hip Outcome Tool 33 and Copenhagen Hip and Groin Outcome Score.

Results

Greater alpha angle was associated with cartilage defects (OR 1.03, 95% CI 1.01 to 1.04) and labral tears (OR 1.02, 95% CI 1.01 to 1.04). Greater alpha angle was associated with superolateral cartilage defects (OR 1.03, 95% CI 1.02 to 1.05) and superior labral tears (OR 1.03, 95% CI 1.02 to 1.05). The association of alpha angle with MRI-defined cartilage defects and labral tears was no greater in football players with symptoms than in those without (p=0.189–0.937)

Conclusion

Cam morphology size was associated with cartilage defects and labral tears in young adult football players with and without pain. This study provides evidence that cam morphology may contribute to the high prevalence of hip OA in football players. Prospective studies of football players are now needed to establish if cam morphology causes progression of cartilage defects and labral tears and development of hip OA.