- Articular cartilage injuries are a challenge to treat, poor at healing, and are an important cause of permanent disability due to the high mechanical joint stress in athletes. They are challenging to treat because of the poor capacity of the articular cartilage to heal itself. The extreme mechanical joint stress comes from repetitive joint impact, rapid deceleration, and frequent pivoting. All of these stresses are detrimental to articular cartilage repair and lead to increased risk of osteoarthritis. Unfortunately, injuries to the articular cartilage of the knee are common sports aliments. (15, 19, 23)
- The microfracture technique is often used to safely and effectively treat traumatic chondral lesions of the load-bearing areas of the knee in athletes. Microfracture has become the main option for athletes suffering from articular cartilage lesions due to its technical simplicity, limited invasiveness, low associated morbidity, and short postoperative rehabilitation. The media has portrayed the procedure as one that can result in rapid decrease in performance and termination of professional athletes' careers. Instead of the procedure being the cause of many careers to end, it is in fact the injury itself that is ending careers. Microfracture has been successful in preserving careers of players with articular cartilage injuries. (15, 17, 19)
- A study published in 2009 found that after a reasonable absence (5-7 months) from activity professional football and rugby players were able to return to their normal sports activity without risking contracts or careers. Twenty four players with isolated full-thickness articular cartilage defects on the weight bearing surface of femoral condyles were treated with microfracture. Healing assessment occurred at 3, 6, 12, 18 months by subjective and objective functional evaluation. The results showed that 83.3% of the players return to full training in an average of 6.2 months and all returned within 18 months. The functional and MRI scores of all subjects improved over the 18 month study. The point of maximal improvement of function occurred between 6 to 12 months. This study should not be used to assess the effects of microfracture on recreational athletes. Recreational athletes do not have the same amount of motivation or the fine facilities that were available to the professionals. (19)
Figure 6: MRI Score Progress
Shows the degree of healing according to MRI evaluation in 6 month periods. The most complete healing occurs at 18 months, although there are no subjects that have no significant healing after 12 months. This study shows that the worst case scenario is that the healing in incomplete.
Permission granted by Masoud Riyami (19)
- In one study, 24 National Basketball Association (NBA) players who had microfracture knee surgery between 1997 and 2006 were evaluated. Data for their first full season before and after the surgery were used in the evaluation. The study found that 8 (33%) of the athletes never returned to play in the NBA. Fourteen players (58.3%) returned to the NBA for longer than one season. Thirteen players (76%) missed at least 1 game during their first full season back from surgery due to injuries to their operative knee. Comparisons within the groups suggested that points scored and minutes played were statistically significantly decreased. Performance variables (points, rebounds, assists, blocks, assists, and field goal percentage) declined between before and after the surgery. When the experimental group was compared to the controls, those players with microfracture knee surgery had a larger average decline in performance. Regression analysis showed that the experimental cases were 8.15 times less likely to remain in the NBA than the controls. The conclusions of the study were that players with a history of microfracture knee surgery are at risk of never returning to the NBA. These results may reflect the players abilities (8 previous all stars), position, age (mean age was 28.6 years old), and the severity of chondral lesions more than they do the success of microfracture. Also the study lacks information about the actual procedures. Lesion size and location do affect the outcome of the procedure. (17)
- The study also found that the players that do return experience a decrease in minutes played directly due to the surgery. The players averaged less points, assists, and rebounds per game. They averaged 3.9 less points per game and 4.0% lower in field goal percentage. (17)
- NBA players who have undergone microfracture knee surgery, when compared with a control group, have a greater decline in performance than the typical non-injured players. This might be more of an indication of the injury rather than the surgery. (17)
TABLE 4
Comparison Between Cases and Controls
Cases (Postoperative Value – Preoperative Value); Controls (Post-index Value –Pre-index Value); P Value
Games played –5.94; –0.81; .521
Minutes per game –5.98; –1.23; .062
Field goal percent –4.0%; –1.0%; .317
Points per game –3.89; –0.80; .013
Points per 40 minutes –2.35; –0.64; .129
Rebounds per game –1.04; –0.68; .435
Rebounds per 40 minutes 0.00; –0.95; .036
Assists per game –0.62; –0.03; .058
Assists per 40 minutes 0.30; 0.07; .648
Steals per game –0.04; –0.09; .553
Steals per 40 minutes 0.55; –0.06; .169
Blocks per game –0.08; –0.12; .637
Blocks per 40 minutes –0.13; –0.16; .793
This table represents the important results from the NBA study. The reason that the per-game stats were affected is due to the decline in minutes following surgery. The per 40 minutes stats show that without the minutes limitation the players would have been as effective as they were pre-injury.
Permission granted by Brian Sennett, (17)
- The 58.3% of NBA players that return to the league for greater than 1 season is less than the 76 % of players that returned to the NFL. (17, 23)
- In 2003, a study was completed that evaluated 25 active National Football League (NFL) players (average age of 29) who underwent microfracture surgery to treat full-thickness chondral lesions (average size of lesion was 380 mm in area ) between 1986 and 1997.With an average follow up of 4.5 years (range 2-13), nineteen of the players (76%) returned to play the season after their surgery after an average of 10 months recovery (range of 4-13 months). The follow ups showed that pain, swelling, running, cutting, squatting, activities of daily living, strenuous work, and strenuous sport all improved after the surgery. The players that returned to action averaged 4.6 seasons (range 1-13) and 57 games (range 2-180) following microfracture. Many of the patients did not produce optimal results until their second postoperative season. As of the 2001-2002 season, nine of the players (36%) continued to play in the NFL. Microfracture improves symptoms, function, and activity levels in the players. This study shows that the treatment does not limit careers but in fact prolongs them. (23)
Figure 1- A grade IV lesion on the medial femoral condyle of a professional football player
Permission granted by Masoud Riyami (19)
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