Orthopaedics & sports medicine
A little exercise a day keeps the doctor away

Many of the detrimental effects of physical inactivity can be reversed, and in some cases improved, by a similar period of moderate exercise. Researchers at Duke University Medical Center Durham, North Carolina, US, have found these results in a new analysis of data from the first randomised clinical trial to evaluate the effects of exercise in sedentary overweight men and women.

Just as important, the trial participants who exhibited the greatest decline in physical status during inactivity benefited the most from exercise training, according to the researchers.

These findings linking the ability of exercise training to reverse the negative effects of inactivity can be attributed to the exercise alone, because the participants did not alter their diets during the trial, the researchers said.

“Continuing to lead an inactive lifestyle leads to a gradual decline in many important markers for cardiovascular health,” said Jennifer Robbins, an exercise physiologist at Duke, who presented the results of the study in June at the annual meeting of the American College of Sports Medicine in Denver.

“The good news is that a small amount of physical activity can make a big difference in reducing the risks for developing such conditions as heart disease, stroke or diabetes,” she said.

“Our findings demonstrate that while the cost of choosing a sedentary lifestyle can be high, switching to an active way of life can be beneficial at any time.” The current study stemmed from a recently completed trial known as STRRIDE (Studies of a Targeted Risk Reduction Intervention through Defined Exercise).

The trial, funded by a US$4.3 million grant from the US National Heart, Lung and Blood Institute, investigated the effects of exercise on sedentary overweight adults at risk for developing heart disease, diabetes, or both. The STRRIDE trial, in which the intervention ran for six months, randomly assigned 334 participants into three different exercise groups and one control group.

“At the end of the trial, we were surprised to see that many markers of cardiovascular health declined in participants in the control group, who did not exercise,” Robbins said. “Our Duke group decided to see if these negative effects could be reversed after the participants spent the same amount of time in an exercise programme.”

Of the 61 STRRIDE participants randomly assigned to the control group 53 agreed to the take part in the new study, which ran an additional six months. The researchers measured 17 biological factors known to increase cardiovascular risk, including waist size, physical fitness, visceral fat levels, body mass index, cholesterol levels, insulin sensitivity and indicators of metabolic syndrome, a precursor of diabetes.

“In the new analysis, we found that waist size, time to exhaustion, visceral fat and metabolic syndrome scores deteriorated significantly during the six-month period of inactivity during the original STRRIDE trial,” Robbins said. “However, after six months of exercise training in the study, 13 of the 17 variables had either reverted to original baseline levels or even improved.”

According to Robbins, only a moderate amount of exercise is needed to counteract the detrimental effects of inactivity in these individuals. The STRRIDE trial measured three levels of physical activity: the equivalents of 19 kilometres of walking per week, 19 km of jogging per week or 32 km of jogging per week.

Participants worked out on treadmills, elliptical trainers or cycle ergometers in a supervised setting. “When looking at the group as a whole, we found it wasn’t the participants with the highest intensity of exercise who accounted for the combined beneficial effects,” Robbins said. “That should be reassuring for people to know they don’t have to do a high-intensity workout to get these benefits of exercise.”

A previous analysis by the Duke group of the same STRRIDE participants, reported in 2005, found another unhealthy effect of physical inactivity: inactive participants gained an average of one kilogramme in six months.

“At that rate, it can be assumed that this group of inactive people would gain nine kilogrammes in five years,” Robbins said. “This means this population of sedentary people needed to exercise just to maintain their current weight. However, our earlier studies have shown that people who exercise can derive many of the cardiovascular risk benefits even in the absence of weight loss.”

Holding the knee surgeon’s hand

Robot assisted partial knee replacement surgery is “significantly more accurate than conventional surgery,” according to a study carried out at London’s Imperial College. The surgical robotic system used in the study was from the Acrobot Company, a spin-out from Imperial College London. “Acrobot” is an acronym for Active Constraint Robot.

Professor Justin Cobb, from Imperial College London, who led the research team looking at the efficacy of the Acrobot system, said: “These robots are designed to hold the surgeon’s hand in the operating theatre, not take over the operation.

This study shows they can be an enormous help, preventing surgeons from making mistakes. More importantly, by showing how the increased accuracy makes a difference to how well a knee works after surgery, we will be able to develop a new generation of less invasive procedures without the risks of error, providing faster recovery and better functional outcomes for patients.”

The system consists of two main components: a surgical planning software and the robotic arm, aka Acrobot – Active Constraint System. The company says the device belongs to a class of products known as Surgical Navigation systems. Briefly, this consists of providing computer-assistance by tracking the spatial locations of tools and patient and depicting them against a pre-operative plan on a computer screen to be used by the surgeon as guidance.

The Acrobot Navigation system improves on existing Surgical Navigation systems in that it provides tooling for soft tissue management and it enables a minimallyinvasive surgical approach. Active Constraint refers to a control technology applied to a motorised programmable device. A tool mounted on the device is confined, by hardware and software, to a certain volume in space.

The device does not move autonomously, although it could be programmed to do so; it reacts to the actions of the surgeon holding a handle attached to the device. It aids motion, if the surgeon is moving the tool inside an allowed spatial volume; it prevents motion outside this volume.

The technology has been successfully proven in clinical trials. During the proof of concept study (2004) 13 unicompartmental knee replacements were carried out with the aid of the Acrobot system, and 15 were performed conventionally. The study demonstrated that the Acrobot system consistently and accurately enables the positioning of prosthetic implant according to a surgical plan.

13 out of 13 Acrobot cases were implanted within 2° of desired orientation. Only out of 15 conventional cases were implanted with this accuracy, with the worst case showing a deviation of 4.2° from the planned position. One additional benefit derived from the study that the company has developed a methodology, based on very low dose CT scans, which enables accurate and quantitative measurement of surgical outcomes providing hard clinical data.

The prototype used in the clinical trial is Mark II of series of devices. It consists of two main components: the Acrobot head and gross positioning device. The reason for the separate positioning device is that, for safety concerns, the Acrobot head was designed to reach a reduced spatial volume and to have three degrees of freedom only.

Prof Cobb said: “This study could have important implications for not just surgery, but also for health economics. By improving the accuracy of surgery, and ultimately improving the outcome for patients, we can make sure the knee replacements work better and last longer, preventing the need for additional surgery.”

Heal that painful heel

Ever wake up in the morning with excruciating heel pain as soon as your feet hit the floor? If so, you’re not alone. Severe heel pain, also known as heel spur syndrome, but technically called plantar fasciitis, affects millions of people around the world each year. But according to a new study published in the August 2006 issue of Journal of Bone and Joint Surgery, those with plantar fasciitis now have a promising treatment option. A newly developed simple stretching protocol that targets plantar fasciitis has noted marked improvement in patients and was found to be superior for treating the inflammatory condition than the traditional weightbearing Achilles tendon stretch.

The study is a two-year follow-up on 82 patients with plantar fasciitis, all of whom were part of an original clinical trial of 101 patients in 2003. The patients were taught a stretch that targets the plantar fascia, the band of tissue that supports the arch and originates on the heel bone and goes to the toes.

The plantar fascia stretching exercise requires the patient to sit with one leg crossed over the other, and stretch the arch of the foot by taking one hand and pulling the toes back toward the shin for a count of 10.

The exercise must be repeated 10 times, and performed at least three times a day, including before taking the first step in the morning and before standing after a prolonged period of sitting. More than 90% of the patients were totally satisfied or satisfied with minor reservations, and noted distinct decrease in pain and activity limitations.

“Plantar fasciitis is everywhere, but we really haven’t had a good handle on it,” said Benedict DiGiovanni, MD, associate professor of orthopaedic surgery at the University of Rochester, US, and author of the study. “The condition often causes chronic symptoms and typically takes about nine to 10 months to burn itself out, and for people experiencing this pain, that’s way too long to suffer through it.”

The study revealed that within three to six months of performing the stretch, patients have a 75% chance of having no pain and returning to full activity. In addition, patients have about a 75% chance of needing no further treatment. “Surgery often involves a prolonged recovery and is associated with about a 50% success rate of eliminating pain and allowing for full activity,” said Dr DiGiovanni.

“But that’s just not good enough. We needed to further optimize non-operative treatments prior to considering surgical options – and if you look at the numbers, we’ve succeeded.”

Back to school:
advice to avoid backpack injury

While it seems that every child carries a backpack during the school year, most parents – and children – are unaware of the potential injury that too-heavy packs can cause.

With school starting in September, Dr Leonel Hunt, director of spine trauma at Cedars-Sinai Institute for Spinal Disorders and Orthopedic Center, Los Angeles, United States, offers some advice to reduce the back and shoulder pain that as many as half of all school children experience each year.

“While backpacks are considered the most efficient way to carry books and other items kids need for school, it’s important they weigh less than 15% of a child’s body weight,” says Dr Hunt.

Otherwise, over time, a child can experience back pain and soreness that can lead to problems that may require medical treatment.” Compared to satchels or briefcases, backpacks are considered safer because they distribute weight evenly across the body and are supported by the back and abdominal muscles.

Children and teens also prefer them because they are fashionable, hold more items, and come with multiple compartments that help them to stay organised. But despite their usefulness, a major study recently reported by the American Physical Therapy Association has found that more than 50% of children surveyed carry backpacks that are too heavy. “When a backpack is filled with heavy books and incorrectly positioned, the weight’s force can pull your child backward.

To compensate, your child may bend forward at the hips or arch his or her back, causing the spine to compress unnaturally,” said Dr Hunt. “This can lead to shoulder, neck and back pain.” Wearing a backpack on one shoulder can also cause the child to lean to one side to compensate for the extra weight and can also lead to pain. In severe cases, children can develop a condition called “scapular winging”, which occurs when the nerve that supplies the shoulder muscle becomes pinched, causing the muscle to not function properly. Girls and younger children may be especially at risk for backpack-related injuries because they are smaller and often carry loads that are heavier in proportion to their body weight.

Recommendations:

1. Keep backpack use limited to necessities only. See that your child cleans out his or her backpack daily by removing any items that can be left at home or in a locker.

2. Distribute weight evenly. Encourage your child to wear both straps of the backpack whenever he or she carries it. This will help distribute the weight of the backpack evenly across the back and promote good posture.

3. Recognise signs that the backpack is too heavy. Pay attention to whether your child is slouched or leaning to one side when wearing a backpack or is experiencing any type of back pain, tingling or numbness in the shoulders or arms.

4. Select the proper backpack. Enhance comfort and safety by purchasing a backpack with multiple compartments, so that weight is more evenly distributed. Padded straps can also help prevent straps from cutting into shoulders. Newer backpacks with wheels are also an option, provided that the handle extends long enough to allow children to stand upright while pulling it. The backpack and wheels must also be sturdy enough so that it does not topple over.

5. Pick up the backpack properly. Teach your child how to pick up his or her backpack by demonstrating how to bend at the knees and grasp the pack with both hands before putting it on.

An alternative to spinal fusion

A systematic literature review of outcomes from 51 clinical studies and case series finds that the Intradiscal Electrothermal Therapy (IDET) procedure would spare up to 65% of patients with chronic lower back pain from spinal fusion surgery.

In addition, the study also found that IDET patients experienced similar outcome benefits when compared against spinal fusion. The study is published in the July issue of Pain Physician, the official journal of the American Society of Interventional Pain Physicians (ASIPP).

Study authors Dr Gunnar BJ Andersson, professor and chairman of orthopaedic surgery, Rush-Presbyterian- St Luke’s Medical Center, Chicago, and Dr Nagy A Mekhail, chairman, Department of Pain Management, Cleveland Clinic Foundation in Ohio, US, systematically reviewed 33 spinal fusion and 18 IDET procedure studies to extract and summarise data on patient characteristics, surgical methods and clinical outcomes.

Currently, spinal fusion is one of the most commonly performed surgeries for chronic lower back pain, however this study found that 14% of spinal fusion patients experienced complications, as compared to zero per cent of patients undergoing the IDET procedure. Potential patient complications from spinal fusion include infection, bleeding, nerve injury, severe pain, and repeat operations.

“Patients with chronic lower back pain often must face the harsh reality that they do not have a good prognosis for recovery with conservative, non-operative management alone,” said Dr. Andersson. “Consequently, a patient is confronted with the option of living with persistent back pain or electing to undergo invasive surgery. This systematic review confirms what we’ve known for some time, that, for the properly selected patient, the IDET procedure is a viable alternative to spinal fusion.”

The systematic review also demonstrates that direct costs associated with the IDET procedure have been estimated at US$7,000 and the costs associated with spinal fusion have been reported in excess of $50,000. These estimates do not include costs associated with the management of postoperative complications, which can be substantial with spinal fusion.

“Based on the similar clinical improvements, such as pain severity and functional impairment, it is reasonable for physicians to consider the IDET procedure prior to considering spinal fusion surgery,” said Dr Mekhail. Studies were selected if patients were diagnosed with disc degeneration or disruption and if follow-up outcome data included evaluations of back pain severity, functional impairment and/or health-related quality of life.

Qualitative comparisons in outcomes were made between spinal fusion and the IDET procedure, as well as each intervention and non-operative conservative management.