The promise of platelets
Optimism persists despite RCT findings
by Jordana Bieze Foster
People are talking about platelet rich plasma . The nonsurgical therapeutic technique has been credited with a SuperBowl comeback, and it’s been criticized in one of the most-respected journals in the literature. Not surprisingly, some are wondering if it’s too good to be true.
The answer just might be that it’s too soon to know, according to Sean T. Grambart, DPM, who presented on the topic in February at the annual meeting of the American College of Foot and Ankle Surgeons.
“My feeling about PRP I would characterize as guarded optimism,” said Grambart, a foot and ankle surgeon at Carle Clinic Associates in Champaign, IL, and a clinical instructor at the University of Illinois School of Medicine. “We don’t have a lot of high level studies. Right now the evidence is mostly anecdotal.”
Platelet rich plasma, fortified with platelets extracted from whole blood using basic cell separation techniques, is believed to promote healing of bone, cartilage, nerves and soft tissues.
Pittsburgh Steelers wide receiver Hines Ward is a believer. In January 2009, he sprained the medial collateral ligament in his right knee—an injury that was predicted to sideline him for at least four weeks. But Ward received a PRP injection the day after his injury, supplemented it with hyperbaric oxygen therapy and rigorous rehabilitation, and two weeks later caught two passes in the Steelers’ Super Bowl victory over the Arizona Cardinals.
But so far, randomized controlled trials to support the anecdotal evidence has been hard to come by. In the case of chronic Achilles tendinopathy, in fact, the findings of a January RCT published in the Journal of the American Medical Association found no significant effect of PRP on pain and activity compared to a saline injection.
The JAMA study, conducted by researchers from Erasmus University Medical Center in Rotterdam, the Netherlands, compared 27 patients who received a single PRP injection with 27 patients who received a saline injection. All subjects performed one week of stretching and 12 weeks of daily eccentric exercises. No significant differences in outcome measures were seen at six, 12 or 24 weeks.
Grambart, who has done PRP on 15 patients with Achilles tendinopathy thus far, suspects that the subjects in the Dutch study were not as severely impaired as those he typically sees.
“The people I’m doing PRP on are people who have failed conservative treatment, so this is being done in lieu of going in and doing open debridement,” he said. “I have not opened up an Achilles tendinopathy patient for debridement in more than a year.”
Grambart also has found that more than one injection may be needed. He tells patients they may need a series of three, but has yet to actually inject any patient more than twice.
“It takes four to six weeks to see an effect. At that point, if the patient is 40 to 50 percent better, I’ll do another injection,” he said.
In Grambart’s practice, PRP plays an even bigger role in treatment of plantar fasciosis, which he distinguishes from plantar fasciitis by the absence of inflammation accompanying the patient’s pain. As he injects, he tears the plantar fascia just slightly so that it will lengthen as it heals, then prescribes a boot to keep the fascia in neutral during activities and while sleeping.
In 89 plantar fasciosis cases so far, 85% of patients have returned to normal activities, 17% have required a second injection, and none have undergone an open procedure.
Grambart expects to see evidence in the literature in the next year and a half that will support these types of anecdotal results.
“I do truly think this is something that’s going to be here to stay,” he said.
Progress after Achilles tendon repair contrasts with rehabilitation protocol
Rehabilitation goals for patients recovering from Achilles tendon repair may be overly ambitious, according to research from the Western Pennsylvania Hospital.
Investigators reviewed 22 patients who underwent surgical repair of Achilles rupture during a two-year, eight-month period, and found that patients for the most part did not achieve rehabilitation goals within the time frame outlined in the hospital’s treatment protocol.
The nine chronic patients began partial weight bearing a mean of 42 days post-surgery, compared to 40 days for the 13 acute patients. However, the protocol called for partial weight bearing at postoperative week three. Similarly, full weight bearing was begun at a mean of 59.9 days in the chronic patients and 55.4 days in the acute patients, whereas the protocol called for full weight bearing by week six.
Return to unrestricted activity, however, was accomplished in the recommended time frame of three to four months post-surgery. The chronic patients took a mean of 120.9 days to return while the acute patients took 88.9 days.
The findings were presented as a poster in February at the annual ACFAS meeting.
Hip strengthening alone fails to alter runners’ risk of patellofemoral pain
Research from the University of Delaware indicates that hip strengthening alone does not correct the running mechanics that contribute to patellofemoral pain. The results also suggest, however, that neuromuscular training might be more effective.
Dynamic hip mechanics were assessed in 20 female runners who were asymptomatic but demonstrated excessive (more than 20°) peak hip adduction during running, before and after a six-week intervention. Ten subjects did hip strengthening exercises three times per week; during the final three weeks, they also received single-leg squat training with visual and oral feedback.
Despite strength gains in the exercise group, no significant changes in running me- chanics were observed. However, peak hip adduction, hip external rotation and contralateral pelvic drop during the single-leg squat test improved in the intervention group—suggesting a response to the neuromuscular aspect of the feed- back training.
“Neuromuscular training might be the best means of changing mechanics,” said Rich Willy, PT, a graduate student at the university who presented the findings in February at the Combined Sections Meeting of the American Physical Therapy Association.
Study finds three ankle foot orthoses equivalent for post-stroke hemiplegia
A Northwestern University gait analysis study of patients with post-stroke hemiplegia failed to detect significant temporospatial differences between three articulated ankle foot orthoses featuring differing degrees of dorsi- and plantarflexion control. All three AFOs, however, provided significant gait benefits compared to an unbraced condition.
The results were presented in February at the annual meeting of the American Academy of Orthotists & Prosthetists.
Researchers analyzed 21 subjects who were a mean of 6.6 years post-stroke. The randomized crossover trial design involved each subject wearing all three braces in random order, with an adjustment period of two weeks prior to testing of each device. The test required subjects to walk 10 meters across six force plates at a self-selected walking speed.
The first AFO featured a 90° plantar flexion stop and free dorsiflexion. The second also allowed free dorsiflexion, but included a custom 90° plantar flexion limiter. The third device combined a 90° plantar flexion stop with a dorsiflexion assist.
Walking speed and step length on the involved side were significantly increased in all three AFO conditions compared to a shoe-only condition. Effects on ankle and knee range of motion were greater in the 11 subjects with knee hyperextension than in the group overall: All three devices were associated with significant increases in ankle angle at initial contact and midswing for the larger group and the subgroup with hyperextension, but only those with hyperextension saw improvements in peak knee angle in loading response.
The device with the plantar flexion limiter was the only one for which ankle angle at midswing was not significantly different from ankle angle at initial contact.
“The plantar flexion limiter altered alignment slightly between the compressed and uncompressed conditions. It may be that the durometers were too hard for them and they didn’t get full compression, or maybe they just don’t compress when they walk,” said Stefania Fatone, PhD, BP&O, a prosthetist-orthotist and research assistant professor in the department of physical medicine and rehabilitation at Northwestern, who presented the findings.
Surprisingly, the AFO with the plantar flexion limiter was associated with greater dorsiflexion during swing than the device with the dorsiflexion assist.
“The dorsiflexion assist joints did not provide additional dorsiflexion during swing,” Fatone said, adding that higher-durometer dorsiflexion-assist joints, which likely provide more of an assist, have become available since the study was undertaken.