Background: Patella alta has been identified as an important risk factor for lateral patellar instability and medial patellofemoral complex (MPFC) reconstruction failure. Purpose: To evaluate the length changes of the MPFC at multiple possible reconstruction locations along the extensor mechanism in varying degrees of patella alta throughout knee motion. Study Design: Controlled laboratory study. Methods: Eight fresh-frozen cadaveric knees were used in this study. The MPFC was identified and dissected with the patellar tendon and quadriceps tendon. A custom-made jig was utilized to evaluate lengths from 0° to 90° of flexion with physiological quadriceps loading. Length was measured with a 3-dimensional robotic arm at 4 possible reconstruction locations along the extensor mechanism: the midpoint patella (MP), the MPFC osseous center (FC), the superior medial pole of the patella (SM) at the level of the quadriceps insertion, and 1 cm proximal to the SM point along the quadriceps tendon (QT). These measurements were repeated at 0°, 20°, 40°, 60° and 90° of flexion. Degrees of increasing severity of patella alta at Caton-Deschamps index (CDI) ratios of 1.0, 1.2, 1.4, and 1.6 were then investigated. Results: Patella alta and MPFC attachment site location significantly affected changes in MPFC length from 0° to 90° of flexion ( P< .0005). Length changes at attachment MP showed no difference when CDI 1.0 was compared with all patella alta values (CDI 1.2, 1.4, 1.6; P > .05). Similarly, FC showed no difference in length change from 0° to 90° until CDI 1.6, in contrast to proximal attachments (SM, QT), which demonstrated significant changes at CDI 1.4 and 1.6. When length changes were analyzed at each degree of flexion (0°, 20°, 40°, 60°, 90°), Spearman correlation analysis showed a moderate negative linear correlation for QT at CDI 1.0 ( r= −0.484; P = .002) and 1.6 ( r = −0.692; P < .0005), demonstrating constant loosening at the QT point at normal and elevated patellar height. In contrast, no differences in length were observed for MP at CDI 1.0 throughout flexion, and at CDI 1.6, there was a difference only at 0° ( P < .05). Points FC and MP at CDI 1.6 had similar length change properties to points SM and QT at CDI 1.0 ( P > .05), suggesting that distal attachments in the setting of patella alta may provide similar length changes to proximal attachmentswith normal height. Conclusion: Anisometry of the MPFC varies not only with attachment location on the extensor mechanism but also with patellar height. Increased patellar height leads to more significant changes in anisometry in the proximal MPFC attachment point as compared with the distal component. In the setting of patella alta, including a CD ratio of 1.6, the osseous attachments of the MPFC remain nearly isometric wheras the proximal half length changes increase significantly. Clinical Significance: The results of this study support the idea that the MPFC should be considered as 2 separate entities (proximal medial quadriceps tendon femoral ligament and distal medial patellofemoral ligament) owing to their unique length change properties.

Having a better understanding of the intersection between chronic pain and obesity in the Mexican American community can be valuable for pain management specialists in determining treatment, service, and prevention strategies. The objectives of this study were (1) to describe the type and severity of chronic pain among overweight/obese Hispanic adults aged 40 years and older, and (2) to determine the association between chronic pain indices and key demographic variables, including excessive weight. Hispanic adults (N=101) were interviewed using validated questionnaires and measured for BMI and waist circumference. Data analyses revealed that most participants had widespread pain; 60% were suffering severe pain (including back, knee, and shoulder pain); the most common pain location was head (headache, 80%), followed by knee and upper back (75-76%), shoulder (73%) and lower back (73%). Greater obesity was associated with some negative pain outcomes. Results are relevant for pain management with this at-risk population.

Recent emphasis has been placed on the effect the built environment has on physical activity levels of children. Children living in poorly planned or urban neighborhoods (areas with limited room or green space for play, lack of sidewalks and streets that do not connect) have less access to physical activity opportunities. The purpose of this article is to describe a shared venture between a public university, nonprofit organization and faith based organization to increase physical activity among children living in a city with limited open space. A mobile physical activity unit (MPAU), which consisted of a renovated passenger bus with playground equipment, was developed and utilized with the intent of providing safe, age-appropriate and supervised activities and games in a parking lot. Hence, children living nearby had access to a “playground” that was non-existent in their neighborhood. The MPAU was made available to children twice per week for 12 weeks. Attendance rates were high, and parents reported positive feedback. The findings suggest that in the absence of joint-use agreements for access to playgrounds after school hours, innovations such as the MPAU may be effective alternatives to increase children’s physical activity levels.

No abstract