Summary

Among age matched athletes and non-athletes with symptomatic cartilage defects who meet demographic criteria for cartilage restoration, non-athletes were more likely to smoke tobacco and have a significantly longer duration of symptoms prior to treatment.

Abstract

Background: Athletes with symptomatic knee cartilage defects tend to have improved outcomes following cartilage restoration procedures compared to non-athletes. It is unclear whether there are intrinsic differences in these populations or if outcome differences reflect different tobacco use rates or cartilage lesion chronicity, size, grade, or location in these two populations.
 
Purpose: To determine whether there are differences in symptomatic knee cartilage defect chronicity, size, grade, or location as well as rates of tobacco use among age-matched athletes versus non-athletes undergoing initial arthroscopic knee surgery who meet demographic and radiographic criteria for cartilage restoration surgery.
 
Methods: Age-matched athletes and non-athletes (n=345 total) age 40 or less (mean 29.7 SD 6.6 years) with a body mass index (BMI) of 35 kg/m2 or less (mean 26.8 SD 4.1) and <50% joint space narrowing on weight bearing radiographs were included. All patients had a symptomatic Outerbridge grade 2 or higher cartilage defect visualized during knee arthroscopy. The relationship between athletic status and chronicity of knee symptoms prior to surgery; tobacco use status; and cartilage defect Outerbridge grade, size, and location at time of surgery were characterized. ? ?

Results: Compared to athletes, non-athletes were more likely to smoke tobacco (31% versus 12%, p<0.001) and had a higher BMI (27.6 kg/m2 SD 4.4 versus 26.2 SD 3.6; p=0.005). Duration of symptoms prior to surgery was shorter among athletes (median 104 days versus 282 days for non-athletes, p<0.001). Grade 4 defects were equally prevalent (35% athletes, 35% non-athletes, p=0.96) as were multi-compartment grade 3-4 lesions (14% non-athletes, 9% athletes, p=0.12). Mean grade 3-4 defect size was similar in the lateral (mean 3.0 cm2 SD 3.2 non-athletes, 2.9 SD 3.1 athletes, p=0.96) and medial compartments (3.6 cm2 SD 2.9 athletes, 3.3 SD 4.2 non-athletes, p=0.82) but there was a trend toward larger anterior compartment defects in non-athletes (4.4 cm2 SD 5.5) versus athletes (2.8 SD 2.3; p=0.07). ? ?

Conclusions: Among age matched athletes and non-athletes with symptomatic cartilage defects who meet demographic criteria for cartilage restoration, non-athletes were more likely to smoke tobacco and have a significantly longer duration of symptoms prior to treatment. Articular cartilage defect size, grade, and location were similar between groups, although high grade anterior defects may be larger in non-athletes. Tobacco use and lesion chronicity may in part explain the discrepancy in outcomes noted between athletic and non-athletic populations following cartilage procedures. ? ?Level of Evidence: III, retrospective comparative study.