Kellie K. Middleton

HGF Mediates the Anti-inflammatory Effects of PRP on Injured Tendons

Platelet-rich plasma (PRP) containing hepatocyte growth factor (HGF) and other growth factors are widely used in orthopaedic/sports medicine to repair injured tendons. While PRP treatment is reported to decrease pain in patients with tendon injury, the mechanism of this effect is not clear. Tendon pain is often associated with tendon inflammation, and HGF is known to protect tissues from inflammatory damages. Therefore, we hypothesized that HGF in PRP causes the anti-inflammatory effects. To test this hypothesis, we performed in vitro experiments on rabbit tendon cells and in vivo experiments on a mouse Achilles tendon injury model. We found that addition of PRP or HGF decreased gene expression of COX-1, COX-2, and mPGES-1, induced by the treatment of tendon cells in vitro with IL-1β. Further, the treatment of tendon cell cultures with HGF antibodies reduced the suppressive effects of PRP or HGF on IL-1β-induced COX-1, COX-2, and mPGES-1 gene expressions. Treatment with PRP or HGF almost completely blocked the cellular production of PGE2 and the expression of COX proteins. Finally, injection of PRP or HGF into wounded mouse Achilles tendons in vivo decreased PGE2 production in the tendinous tissues. Injection of platelet-poor plasma (PPP) however, did not reduce PGE2 levels in the wounded tendons, but the injection of HGF antibody inhibited the effects of PRP and HGF. Further, injection of PRP or HGF also decreased COX-1 and COX-2 proteins. These results indicate that PRP exerts anti-inflammatory effects on injured tendons through HGF. This study provides basic scientific evidence to support the use of PRP to treat injured tendons because PRP can reduce inflammation and thereby reduce the associated pain caused by high levels of PGE2.

Progression of patellar tendinitis following treatment with platelet-rich plasma: case reports

PurposeThe use of platelet-rich plasma (PRP) is becoming more attractive given its favourable side effect profile and autologous nature, leading to rapid clinical adoption in the absence of high-level evidence. We are presenting three patients who developed a progression of patellar tendinitis following treatment, which to our knowledge is the first report of worsening of patellar tendinitis following PRP therapy.MethodsThe records of three patients with symptom exacerbation of patellar tendinitis following treatment with PRP were reviewed. IRB exemption was obtained. Clinical and operative records, radiographs, and MR imaging were reviewed for all patients.ResultsThree patients reported to our clinic for a second opinion with symptoms of anterior knee pain consistent with patellar tendinitis. Each patient had previously been treated with PRP therapy due to prolonged symptoms. Clinical and radiological findings following treatment included patellar tendon thickening, worsening pain, discontinuation of athletic participation in all three patients, and osteolysis of the distal pole of the patella in one patient identified during surgical intervention.ConclusionsGrowing interest in the use of autologous products for the management of chronic tendinopathies has led to widespread clinical implementation with minimal scientific support. It is tempting to apply a new treatment for management of a difficult clinical entity, especially when the risk/benefit ratio appears favourable. However, caution must be exercised as unexpected results may be encountered.Level of evidenceCase reports, Level V.

Individualized anatomic anterior cruciate ligament reconstruction.

Arthroscopic anterior cruciate ligament reconstruction (ACL-R) is a technique that continues to evolve. Good results have been established with respect to reducing anteroposterior laxity. However, these results have come into question because nonanatomic techniques have been ineffective at restoring knee kinematics and raised concerns that abnormal kinematics may impact long-term knee health. Anatomic ACL-R attempts to closely reproduce the patients individual anatomic characteristics. Measurements of the patients anatomy help determine graft choice and whether anatomic reconstruction should be performed with a single- or double-bundle technique. The bony landmarks and insertions of the anterior cruciate ligament (ACL) are preserved to assist with anatomic placement of both tibial and femoral tunnels. An anatomic single- or double-bundle reconstruction is performed with a goal of reproducing the characteristics of the native ACL. Long-term outcomes for anatomic ACL reconstruction are unknown. By individualizing ACL-R, we strive to reproduce the patients native anatomy and restore knee kinematics to improve patient outcomes.

Acl Graft Position Affects in Situ Graft Force Following Acl Reconstruction

BACKGROUND The purpose of our study was to evaluate the relationship between graft placement and in situ graft force after anterior cruciate ligament (ACL) reconstruction. METHODS Magnetic resonance imaging (MRI) was obtained for twelve human cadaveric knees. The knees, in intact and deficient-ACL states, were subjected to external loading conditions as follows: an anterior tibial load of 89 N at 0°, 15°, 30°, 45°, 60°, and 90° of flexion and a combined rotatory (simulated pivot-shift) load of 5 Nm of internal tibial torque and 7 Nm of valgus torque at 0°, 15°, and 30° of flexion. Three ACL reconstructions were performed in a randomized order: from the center of the tibial insertion site to the center of the femoral insertion site (Mid), the center of the tibial insertion site to a more vertical femoral position (S1), and the center of the tibial insertion site to an even more vertical femoral position (S2). The reconstructions were tested following the same protocol used for the intact state, and graft in situ force was calculated for the two loadings at each flexion angle. MRI was used to measure the graft inclination angle after each ACL reconstruction. RESULTS The mean inclination angle (and standard deviation) was 51.7° ± 5.0° for the native ACL, 51.6° ± 4.1° for the Mid reconstruction (p = 0.85), 58.7° ± 5.4° for S1 (p < 0.001), and 64.7° ± 6.5° for S2 (p < 0.001). At 0°, 15°, and 30° of knee flexion, the Mid reconstruction showed in situ graft force that was closer to that of the native ACL during both anterior tibial loading and simulated pivot-shift loading than was the case for S1 and S2 reconstructions. At greater flexion angles, S1 and S2 had in situ graft force that was closer to that of the native ACL than was the case for the Mid reconstruction. CONCLUSIONS Anatomic ACL reconstruction exposes grafts to higher loads at lower angles of knee flexion. CLINICAL RELEVANCE Rehabilitation and return to sports progression may need to be modified to protect an anatomically placed graft after ACL reconstruction.

Racial differences in heart rate variability during sleep in women: the study of women across the nation sleep study.

Background Heart rate variability (HRV) differs markedly by race, yet few studies have evaluated these relationships in women, and none have done so during sleep (sHRV). Methods We addressed these gaps by examining sHRV in women of African American, Chinese American, or European American origin or descent (mean [standard deviation] age = 51.2 [2.2] years). Results HRV during Stage 2 non–rapid eye movement (NREM) and rapid eye movement (REM) sleep differed significantly by race after adjusting for possible confounders. Normalized high-frequency HRV was significantly lower in European American compared with African American and Chinese American participants (European American NREM = 0.35 [0.01], REM = 0.23 [0.01]; African American NREM = 0.43 [0.02], REM = 0.29 [0.02]; Chinese American NREM = 0.47 [0.03], REM = 0.33 [0.02]; p values <.001). European Americans also exhibited higher low-to-high-frequency HRV ratios during sleep compared with African American and Chinese American women (European American NREM = 2.42 [1.07], REM = 5.05 [1.07]; African American NREM = 1.69 [1.09], REM = 3.51 [1.09]; Chinese American NREM = 1.35 [1.07], REM = 2.88 [1.13]; p values <.001). Conclusions Race was robustly related to sHRV. Compared with women of African American or Chinese American origin or descent, European American women exhibited decreased vagally mediated control of the heart during sleep. Prospective data are needed to evaluate whether sHRV, including race differences, predicts cardiovasular disease.

An Exercise Prescription for Healthy Active Aging

Our collective “population” is aging with both the number of people over the age of 65 years steadily rising and the fact that individuals are living longer lives. The World Health Organization (WHO) estimates that by 2050, the number of adults aged 80 or older will approach 400 million worldwide. In an effort to improve efficiency and ensure that the healthcare system is able to care for such growth, health promotion and prevention are key. One method to promote healthy aging and prevent morbidity and mortality associated with chronic disease is through exercise. There are multiple benefits of exercise, particularly for those in their sixth decades and beyond. Benefits of exercise include chronic illness prevention and risk reduction, preservation of quality of life, improved psychological well-being, and social benefits affecting an individual’s community. The WHO provides clear guidelines on physical activity focusing on building and maintaining core strength, balance, and flexibility and bolstering cardiovascular stamina through regular aerobic activity. Unfortunately, recommendations without adherence and execution are mute. This highlights the importance of understanding a patient’s personal perspective on exercise and individual health goals. The aging population may be faced with various challenges such as decreased access to exercise facilities (e.g., affordability, transportation) and age-appropriate programs. The purpose of this chapter is to discuss the benefits of exercise, WHO recommendations on physical activity, and barriers to regular exercise in those over the age of 65 and to provide an example of an exercise program or “a prescription for healthy aging.”

Maximizing Performance and Preventing Injury in Masters Athletes

Masters athletes exhibit persistently high levels of functional capacity helping them advance through a healthy aging process. When evaluating the trend of top performances among masters athletes, performance continues to improve within age categories [1, 2]. However, the capacity for performance in athletics does decrease as people age. The rate of decline has been evaluated by several studies. When examining the track and field performance of senior athletes, both male and female performance decreased at approximately 3.4% for each year after the age of 50 in a relatively linear fashion, until the age of 75, where performance begins to fall more precipitously, with a decline of greater than 7% in performance times annually [3]. Furthermore, the age of maximum performance increases with greater race distances, and the rate of slowing as athletes age decreases as competition distances increase [4]. This is consistent with known shifts that take place within skeletal muscle: the percentages of slow-twitch type I muscle fibers increase with increasing age [5–11]. Similar findings are noted in other sports as well [12]. Masters swimmers also demonstrate a modest, linear decrease in performance of 0.6–1% per year until age 70, when a more rapid decline is noted [13, 14]. In Ironman triathletes, age-related rates of decline in performance are 13% for men and 15% for women each decade until age 70; with greater declines noted in swimming and running than cycling [1].

Common Hip Injuries: Conservative Management

Full functionality of the hip is crucial in athletes who seek to optimize their performance. As the primary stabilizer of the body, a strong and pain-free hip is especially essential for master athletes. Unfortunately, athletes 35 years and older are prone to many hip pathologies that typically do not affect younger athletes due to various factors. Such factors include degenerative changes in the hip joint, overuse and secondary strain of the surrounding musculature, and great stress on the joint from many years of high activity. As such, this chapter will focus on the management of common hip injuries seen in aging athletes, both conservative and operative, and the success of these patients returning to sport following treatment.

Maximizing Nutrition and Supplements for Masters Athletes

A fundamental component for any athlete’s performance is nutrition. Athletes spend months training for one specific event. Often, nutrition is mistakenly left out of their plan, or an afterthought post-event. Nutrition needs to be one of the essential tools in all every athletes’ training regimen and toolbox for success. Good nutrition or a healthy “sports diet” can overcome limiting factors that would otherwise cause fatigue or a decrease performance. The fuel demands for many sports are complex and often misunderstood. As such, the goals of this chapter are to review the principles and benefits of healthy nutrition.