UCSF

Background

Injuries to the articular cartilage in the knee are common in jumping athletes, particularly high-level basketball players. Unfortunately, these are often diagnosed at a late stage of the disease process, after tissue loss has already occurred.

Purpose/hypothesis

To evaluate longitudinal changes in knee articular cartilage and knee function in National Collegiate Athletic Association (NCAA) basketball players and their evolution over the competitive season and off-season.

Study type

Longitudinal, multisite cohort study.

Population

Thirty-two NCAA Division 1 athletes: 22 basketball players and 10 swimmers.

Field strength/sequence

Bilateral magnetic resonance imaging (MRI) using a combined T_1ρ and T₂ magnetization-prepared angle-modulated portioned k-space spoiled gradient-echo snapshots (MAPSS) sequence at 3T.

Assessment

We calculated T₂ and T_1ρ relaxation times to compare compositional cartilage changes between three timepoints: preseason 1, postseason 1, and preseason 2. Knee Osteoarthritis Outcome Scores (KOOS) were used to assess knee health.

Statistical tests

One-way variance model hypothesis test, general linear model, and chi-squared test.

Results

In the femoral articular cartilage of all athletes, we saw a global decrease in T₂ and T_1ρ relaxation times during the competitive season (all P < 0.05) and an increase in T₂ and T_1ρ relaxation times during the off-season (all P < 0.05). In the basketball players' femoral cartilage, the anterior and central compartments respectively had the highest T₂ and T_1ρ relaxation times following the competitive season and off-season. The basketball players had significantly lower KOOS measures in every domain compared with the swimmers: Pain (P < 0.05), Symptoms (P < 0.05), Function in Daily Living (P < 0.05), Function in Sport/Recreation (P < 0.05), and Quality of Life (P < 0.05).

Conclusion

Our results indicate that T₂ and T_1ρ MRI can detect significant seasonal changes in the articular cartilage of basketball players and that there are regional differences in the articular cartilage that are indicative of basketball-specific stress on the femoral cartilage. This study demonstrates the potential of quantitative MRI to monitor global and regional cartilage health in athletes at risk of developing cartilage problems.

Level of evidence

2 Technical Efficacy Stage: 2.