Patellar mobility and lower limb kinematics during functional activities in individuals with and without patellar tendinopathy

STUDY DESIGN

Case-control.

OBJECTIVE

To examine whether patients with patellar tendinopathy (PT) display greater patellar mobility and different lower body kinematics than patients without PT.

BACKGROUND

PT is a common overuse condition of the patellar tendon that can cause pain and impair function. Subjects with overuse knee problems display different hip and knee functional mechanics, specifically valgus collapse. Patellar hypermobility has not been specifically studied as a possible risk factor for PT.

METHODS

11 patients with PT and 11 controls without PT, age 18 to 40, were studied. Using a patellofemoral arthrometer (PFA), maximal lateral and medial patellar displacement was measured. 3-D motion analysis was performed to determine lower extremity joint motions during single-leg step down and drop vertical jump tests.

RESULTS

Patients with PT had significantly increased lateral patellar mobility compared to controls (12.21 ± 3.33 mm vs. 9.19 ± 1.92 mm, P = .017). PT patients showed significantly greater peak hip adduction with both drop vertical jump (2.7° ± 6.3° vs. -5.6° ± 4.2°; P = .003) and step down (17.0° ± 3.8° vs. 12.5° ± 4.4°, P = .024). PT patients demonstrated increased peak ankle external rotation with drop vertical jump (-21.1° ± 5.9° vs. -14.8° ± 5.5°, P = .023) and step down (-15.6° ± 5.5° vs. -9.0° ± 6.0°, P = .017).

CONCLUSIONS

Patients with PT exhibit increased lateral patellar mobility, hip adduction, and ankle external rotation. The effects of increased patellar mobility deserve further study in the development, management, and prevention of PT.

Youth Distance Running: Strategies for Training and Injury Reduction

Running is a popular sport for children in the United States. However, review of available literature on health effects and safety recommendations for youth running has not been previously conducted. Unique factors for injury include periods of growth during puberty and potential for growth plate injury. Youth runners may benefit from activities that incorporate high-impact loading and multidirectional movement for optimal bone maturation, exercises to strengthen tendons and muscles, and strategies aimed at improving running biomechanics to reduce risk of injury. In addition, addressing lifestyle factors, including nutrition and sleep is essential for a runner's general health. Similar to other sports, sports specialization should not be encouraged in youth runners. Reducing running-related injury in growing children and assessing readiness for running should be based on a combination of physical, emotional, psychological, social, and cognitive factors. Youth runners require individualized training and competition to safely participate in the sport.

High-field magnetic resonance imaging assessment of articular cartilage before and after marathon running: does long-distance running lead to cartilage damage?

BACKGROUND

There is continuing controversy whether long-distance running results in irreversible articular cartilage damage. New quantitative magnetic resonance imaging (MRI) techniques used at 3.0 T have been developed including T1rho (T1ρ) and T2 relaxation time measurements that detect early cartilage proteoglycan and collagen breakdown.

HYPOTHESIS

Marathon runners will demonstrate T1ρ and T2 changes in articular cartilage on MRI after a marathon, which are not seen in nonrunners. These changes are reversible.

STUDY DESIGN

Cohort study; Level of evidence, 2.

METHODS

Ten asymptomatic marathon runners had 3-T knee MRI scans 2 weeks before, within 48 hours after, and 10 to 12 weeks after running a marathon. The T1ρ and T2 MRI sequences in runners were compared with those of 10 age- and gender-matched controls who had MRI performed at baseline and 10 to 12 weeks.

RESULTS

Runners did not demonstrate any gross morphologic MRI changes after running a marathon. Postmarathon studies, however, revealed significantly higher T2 and T1ρ values in all articular cartilage areas of the knee (P < .01) except the lateral compartment. The T2 values recovered to baseline except in the medial femoral condyle after 3 months. Average T1ρ values increased after the marathon from 37.0 to 38.9 (P < .001) and remained increased at 3 months.

CONCLUSION

Runners showed elevated T1ρ and T2 values after a marathon, suggesting biochemical changes in articular cartilage, T1ρ values remain elevated after 3 months of reduced activity. The patellofemoral joint and medial compartment of the knee show the highest signal changes, suggesting they are at higher risk for degeneration.

Elbow arthroscopy in the pediatric and adolescent population

PURPOSE

The purpose of this study was to show the diagnostic and therapeutic benefits of elbow arthroscopy in athletically active pediatric patients. We describe our techniques for elbow arthroscopy in young patients.

TYPE OF STUDY

Case series of 47 patients.

METHODS

We reviewed 49 cases of elbow arthroscopies performed in 47 pediatric and adolescent patients retrospectively over a 16-year period. Charts were reviewed to identify the age of patients at the time of surgery, side involved, hand dominance, diagnosis, complications, the primary sport involved, and the average volume of loose bodies if surgical removal was performed. Each patient was contacted after a minimum of 2 years after surgery and a modified Andrews elbow scoring system was used to rate elbow function.

RESULTS

The average age of this group was 14.0 years (range, 3.5 to 17.0 years) with an average follow-up of 4.7 years. Elbow arthroscopy was performed for osteochondritis dissecans (58%), arthrofibrosis and joint contracture (20%), synovitis (10%), acute trauma (10%), and posterior olecranon impingement syndrome (5%). Based on a modified Andrews elbow scoring system, 85% of patients had good or excellent result with 90% of the children returning to sports without limitation. No patient experienced nerve injury, infection, or loss of elbow motion as a postoperative complication.

CONCLUSIONS

This series shows that elbow arthroscopy has a safe and effective role in the treatment of selective elbow pathologies in the pediatric and adolescent population when performed by experienced small joint arthroscopists.