Spine & Sports Institute

Abstract

Background: Hypoxia and decreased blood supply have been proposed as risks for tendon rupture. Visualization of the vascularity of intact and torn rotator cuffs would be useful for improving treatments for rotator cuff tear.

Purpose: To assess vascularity inside a tendon or an adjacent rotator cuff insertion point in patients differing in age and extent of damage to the tendon.

Study Design: Cross-sectional study; Level of evidence, 3.

Methods: Ten volunteers (all men) and 15 patients (10 men, 5 women) consented to participate in the study. Contrast agent for enhanced ultrasound was injected intravenously. Enhanced ultrasound images of the torn cuff and the contralateral shoulder were recorded for 1 minute. Four small regions of interest, the articular and bursal sides of the tendon and the medial and lateral sides of the bursa, were studied in all shoulders.

Results: There was a significant decrease in blood flow in the intratendinous region in elderly subjects compared with young subjects, but age had no effect on blood flow in bursal tissue. Blood flow in ruptured rotator cuffs did not differ from that in intact rotator cuffs. The intraclass correlation coefficient for intraobserver reproducibility was 0.82 (95% confidence interval: 0.77-0.86).

Conclusions: The findings of this investigation were the hypovascular pattern in intratendinous tissue compared with the subacromial bursa, the age-related decrease in intratendinous vascularity, and the hypovascular pattern in the tendon, regardless of rupture of the tendon. Clarification of vascular patterns inside or around the torn ends of a rotator cuff will assist in the development of successful treatments for torn rotator cuffs.

Abstract

Background: Little epidemiological information exists on overuse injuries in elite road cyclists. Anecdotal reports indicate anterior knee pain and lower back pain may be common problems.

Purpose: This study was conducted to register overuse injuries among professional road cyclists with special focus on anterior knee and lower back pain.

Study Design: Descriptive epidemiology study.

Methods: We attended training camps of 7 professional teams and interviewed 109 of 116 cyclists (94%) on overuse injuries they had experienced in the previous 12 months. Injuries that required attention from medical personnel or involved time loss from cycling were registered. Additional information on anterior knee pain and lower back pain was collected using specific questionnaires.

Results: A total of 94 injuries were registered; 45% were in the lower back and 23% in the knee. Twenty-three time-loss injuries were registered—57% in the knee, 22% in the lower back, and 13% in the lower leg. Fifty-eight percent of all cyclists had experienced lower back pain in the previous 12 months, and 41% of all cyclists had sought medical attention for it. Thirty-six percent had experienced anterior knee pain and 19% had sought medical attention for it. Few cyclists had missed competitions because of pain in the lower back (6%) or anterior knee (9%).

Conclusion: Lower back pain and anterior knee pain were the most prevalent overuse injuries, with knee injuries most likely to cause time loss and lower back pain causing the highest rates of functional impairment and medical attention.

Clinical Relevance: Future efforts to prevent overuse injuries in competitive cyclists should focus on lower back pain and anterior knee pain.

Abstract

Background: Pelvis and trunk motions during baseball pitching are associated with ball velocity. Thus, limits in hip flexibility may adversely affect pitching biomechanics and the ability to generate ball velocity.

Hypotheses: Professional baseball pitchers will have less passive range of motion in the nondominant hip and the measured ranges of motion of both the nondominant and dominant hips will correlate with biomechanical parameters of the lower extremity among professional pitchers.

Study Design: Cross-sectional study; Level of evidence, 3.

Methods: Nineteen healthy professional baseball pitchers volunteered for testing. Fluid goniometry was used to measure passive range of motion of adduction (ADD), abduction (ABD), internal rotation, external rotation, total arc of rotation, and total arc of ADD + ABD. Pitching biomechanical data were collected using an automated 3-dimensional motion analysis system while participants threw fastballs.

Results: Pitchers possessed significantly less passive range of motion in the nondominant hip when compared with the dominant hip for all ranges. Total arc of rotation of the nondominant hip correlated with ball velocity (r = .50). Total arc of ADD + ABD in the nondominant hip and ABD in the nondominant hip were correlated with stride length (r = −.72 and .70, respectively). Dominant hip ABD (r = .63), total arc of rotation in the nondominant hip (r = −.45), and total arc of ADD + ABD of the dominant hip (r = .44) were correlated with trunk separation. Total arc of ADD + ABD of the nondominant hip (r = −.52) and total arc of rotation of the dominant hip (r = −.44) were correlated with pelvic orientation.

Conclusion: Passive range of motion is smaller in the nondominant hip than the dominant hip among professional pitchers. The measured disparity between the hips is significantly correlated with various pitching biomechanical parameters of the trunk and pelvis. Future research is required to investigate a causal relationship between less hip passive range of motion and both ball velocity and pitching biomechanics.

Abstract

Background: Platelet-rich plasma (PRP) has been used to enhance tendon healing in clinical settings. However, the cellular mechanisms underlying PRP treatment of injured tendons remain unclear. The aim of this study was to determine the effects of PRP, in the form of PRP-clot releasate (PRCR), on tendon stem cells (TSCs), a newly discovered cell population in tendons.

Hypothesis: The PRCR treatment promotes differentiation of TSCs into tenocytes that are activated to proliferate quickly and increase collagen production.

Study Design: Controlled laboratory study.

Methods: After PRCR treatment, cell morphology, expression of stem/progenitor cell marker nucleostemin, and population doubling time were examined. In addition, gene and protein analyses were performed using reverse transcription-polymerase chain reaction, immunocytochemistry, and Western blot to characterize the type of cells that had differentiated after PRCR treatment.

Results: The TSCs without PRCR treatment were small and exhibited an irregular shape, whereas with increasing PRCR dosage, TSCs became large, well spread, and highly elongated with downregulation of nucleostemin expression. The PRCR treatment also markedly enhanced TSC proliferation, tenocyte-related gene and protein expression, and total collagen production, all of which indicated that PRCR treatment induced differentiation of TSCs into activated tenocytes.

Conclusion: The PRCR treatment promotes differentiation of TSCs into active tenocytes exhibiting high proliferation rates and collagen production capability.

Clinical Relevance: The findings of this study suggest that PRP treatment of injured tendons is “safe” as it promotes TSC differentiation into tenocytes rather than nontenocytes, which would compromise the structure and function of healing tendons by formation of nontendinous tissues. Moreover, they suggest that PRP treatment can enhance tendon healing because tenocytes induced to differentiate by PRP are activated to proliferate quickly and produce abundant collagen to repair injured tendons that have lost cells and matrix.

Abstract

Background: Autologous chondrocyte implantation (ACI) is an accepted surgical treatment in patients with isolated cartilage defects of the knee. Age has been considered as a limiting factor and the technique has not been recommended in patients older than 40 to 50 years. Nevertheless, some more recent studies report satisfying clinical results in middle-aged patients.

Hypothesis: Analogous to the microfracture technique, age over 40 years is associated with inferior clinical outcome after ACI.

Study Design: Cohort study; Level of evidence, 2.

Methods: Thirty-seven patients with an average age of 47.8 years (group 1) were matched with 37 patients with an average age of 31 years (group 2). Both groups underwent ACI for treatment of isolated cartilage defects of the knee. All patients were enrolled prospectively and followed for a period of 24 months using International Knee Documentation Committee (IKDC), Lysholm scale, Cincinnati sports scale, and Tegner activity evaluation instruments.

Results: Statistical analysis revealed a significant increase in function after ACI in both groups as early as 6 months after surgery until the end of the study period. There was only a slight tendency for better clinical outcome in younger patients (IKDC at 24 months: group 1, 72.2 ± 15.8 [standard deviation]; group 2: 76.1 ± 14.1; P = .261; Lysholm at 24 months: group 1: 80.42 ± 15.37; group 2: 80.65 ± 12.01), no statistical significant differences were found between patients of group 1 and group 2 at any of the time points investigated.

Conclusion: In contrast to other cartilage repair techniques, patients 40 years and older do not have an inferior outcome up to 24 months after ACI for isolated cartilage defects when compared with younger patients.

Abstract

Background: An estimated 136 000 concussions occur per academic year in high schools alone. The effects of repetitive concussions and the potential for catastrophic injury have made concussion an injury of significant concern for young athletes.

Purpose: The objective of this study was to describe the mechanism of injury, symptoms, and management of sport-related concussions using the High School Reporting Information Online (HS RIO) surveillance system.

Study Design: Descriptive epidemiology study.

Methods: All concussions recorded by HS RIO during the 2008-2009 academic year were included. Analyses were performed using SPSS software. Chi-square analysis was performed for all categorical variables. Statistical significance was considered for P < .05.

Results: A total of 544 concussions were recorded. The most common mechanism (76.2%) was contact with another player, usually a head-to-head collision (52.7%). Headache was experienced in 93.4%; 4.6% lost consciousness. Most (83.4%) had resolution of their symptoms within 1 week. Symptoms lasted longer than 1 month in 1.5%. Computerized neuropsychological testing was used in 25.7% of concussions. When neuropsychological testing was used, athletes were less likely to return to play within 1 week than those for whom it was not used (13.6% vs 32.9%; P < .01). Athletes who had neuropsychological testing appeared less likely to return to play on the same day (0.8% vs 4.2%; P = .056). A greater proportion of injured, nonfootball athletes had computerized neuropsychological testing than injured football players (23% vs 32%; P = .02)

Conclusion: When computerized neuropsychological testing is used, high school athletes are less likely to be returned to play within 1 week of their injury. Concussed football players are less likely to have computerized neuropsychological testing than those participating in other sports. Loss of consciousness is relatively uncommon among high school athletes who sustain a sport-related concussion. The most common mechanism is contact with another player. Some athletes (1.5%) report symptoms lasting longer than 1 month.