Bone Loss Persists Post ACL Surgery

A study conducted at the Mayo Clinic in Rochester, Minn, has found that 2 years after anterior cruciate ligament (ACL) surgery, young female athletes still show substantial bone loss in the femur, tibia, and patella areas, usually 3 to 6 months after corrective surgery. Such loss, they report, is partially reversed by 2 years of focused therapy.

The study authors tracked 22 women between the ages of 16 and 40 who had experienced a complete ACL rupture. All the participants underwent ACL reconstructive surgery, after which they participated in a rigorous rehabilitation program. The patients performed range-of-motion and closed-chain exercises during the early phases of rehabilitation. When motion was full and swelling decreased, the program was continued. Running began at 3 months and plyometric exercises began at 4 months, with return to sport when functional and isokinetic testing showed at least 80% functionality of the opposite limb and the patient felt functionally stable.

The results showed that although no bone loss was found in the spinal region or at the unaffected limbs, bone loss in the injured areas did occur—most dramatically at the 3-month point following surgery. The study also found that women with a higher body-mass index suffered more bone loss than leaner women. On the other hand, exercise and walking helped minimize bone loss.

“Since we did find a correlation between improved bone density and higher Tegner scores at 2 years, it would be reasonable to encourage patients to return to regular weight-bearing activities and sports,” says Diane L. Dahm, MD, assistant professor of orthopedics at the Mayo Clinic. “With the numbers available, we were not able to show an improvement in bone-mineral density with increased isokinetic strength or functional tests.”

A larger study, which will most likely include a treatment arm (calcium and vitamin D), is expected to be completed over the next 3 years.

Obesity Researchers Test “Classroom of the Future”

Researchers from the Mayo Clinic are targeting childhood obesity and are examining what society thinks of a school classroom. They have asked a simple question: Do children really need to sit at desks while they learn? To find the answer, they designed what they believe is the first chairless classroom.

“Giving children the option to move in a new kind of classroom can only add activity to their day, and increased activity is a key to improved health,” says James Levine, MD, PhD, Mayo Clinic obesity researcher. “Obesity among our children is at a terrifying level. Whatever can be done to change their environment to encourage activity should be a priority.”

To test the “classroom of the future,” a team of business and organization leaders was assembled and an indoor village to house the classroom was built at the Rochester Athletic Club in Rochester, Minn. Apple provided iBook wireless notebook computers and iPods that play video.

Levine developed the school’s concepts during 2 decades of international research. Some of the classroom’s innovations were video-streamed pod-casting as a teaching aid, learn n’ move bays, personalized laptop computers, personalized whiteboards, and standing desks.

For 1 week, 30 fourth- and fifth-graders’ activities in the traditional classroom were measured. Then, for 1 week, the students were moved to the school of the future, where their activities in the new environment were monitored and educational tests were performed. The researchers collected data on the students’ movements using telemetry called Posture and Activity Detectors (PADs), which each student wore. The PADs measured the time spent standing and walking.

“We were very surprised to find that the children had no trouble focusing on the teacher and their work in our experiment,” Levine says. “Their attention did not wander; rather, they were riveted to what was being taught.”

According to Levine, the “classroom of the future” will also prevent diabetes, high cholesterol and blood pressure, joint and back problems, and depression in children.

Full Meniscectomy Facilitates Cartilage Loss

The March 2006 issue of Arthritis & Rheumatism reveals the results of a study that found a high correlation between meniscal malposition and meniscal damage. The study sheds light on the importance of an intact and functioning meniscus for patients with symptomatic knee osteoarthritis (OA).

“The meniscus plays an important role in stabilizing and load distributing in the knee, such that when it is removed or damaged it does not perform this function,” says study leader David Hunter, Boston University School of Medicine. “This particularly compressive load tends to load focally on smaller areas and potentially via this mechanism lead, to degenerative change.”

The study focused on 257 subjects (58% were men, and their mean age was 66.6 years old) who were enrolled in the Boston Osteoarthritis of the Knee study. At the study’s onset and follow-up examinations at 15 and 30 months, participants underwent magnetic resonance imaging (MRI) of the more symptomatic knee. Using the images, the researchers measured the position of the meniscus and evaluated and scored the severity of meniscal damage. The MRI assessments found that 29% had a previous injury, 27% had a previous surgery, and 5% had a previous meniscectomy.

The results found that the impact of meniscal abnormality on cartilage loss was most pronounced in the medial Tibiofemoral joint. Each measure of meniscal misalignment was associated with an increased risk of cartilage loss. Reductions in the coverage and height of the meniscus, provoked by partial dislocation of the meniscus, also increased the risk of cartilage loss.

According to Hunter, when a meniscal is damaged, a number of therapeutic options are available. As meniscal damage is almost universal in knees with OA, removing the meniscus (in the absence of symptoms like locking) will only facilitate more rapid progression of cartilage loss. So the best option is to leave it alone and manage the knee conservatively. In the presence of symptoms such as locking, it may be necessary to operate, in which instance it is preferable to leave as much of the meniscus as intact as possible either via repairing the tear or performing a partial meniscectomy.

“At present, efforts are being made to preserve a damaged meniscus rather than remove it,” Hunter says. “Our study points to the need for critical, prospective evaluation of these new therapeutic options.”