MU Knee Process Receives Federal Approval for Human Clinical Trials

Contact: Christian Basi
Assistant Director
573-882-4430
BasiC@missouri.edu

MU Knee Process Receives Federal Approval for Human Clinical Trials
Implants Designed by MU Veterinarian Could Help Millions Every Year


COLUMBIA, Mo.--Each year, millions of people undergo surgery to repair damaged cartilage in their knees. Unfortunately, in most of those cases, doctors simply remove the damaged cartilage and leave nothing in its place, nearly ensuring that patients will experience painful arthritis as they age. However, a process developed by a University of Missouri-Columbia researcher that has received FDA approval recently, helps the knee to generate cartilage without the use of drugs.

One common cause of osteoarthritis, the most common form of arthritis, occurs when an area of knee cartilage is damaged and must be removed during surgery. The cartilage, known as the meniscus, is a shock absorber in the knee. When torn or damaged, the meniscus typically does not heal on its own, and the damaged portion is removed and not replaced. While current surgical techniques solve the short-term problem, osteoarthritis inevitably develops several years later. James Cook, an MU professor of veterinary medicine and surgery, has performed groundbreaking research for DePuy Orthopaedics Inc. to help develop a process that successfully encourages the meniscus to repair itself, while minimizing progression of osteoarthritis for the patient.

"Other studies have shown the amount of arthritis a person experiences is related to the amount of meniscus you have left in your knee," Cook said. "In our animal studies, we have been able to grow back 90 percent of the meniscus on average. Using tissue engineering and biological stimulation through the implantation of a scaffold derived from pig intestines, we show the tissue where it needs to grow. With approval from the federal government, we will now be able to begin using this in humans in the first phase of clinical trials."

While the new process has been used in more than 300 dogs, about 20 human patients will receive the procedure in the trials, which will be completed by surgeons in Memphis and Indianapolis. Following a successful first phase, the trials will be opened nationwide for a second, larger trial before finally being available to the public. Cook expects that process to take about 3-6 years. Ideal patients for the trials are those individuals who are in good health, but are suffering from a meniscal tear that will extend to the vascular zone of the meniscus when surgically treated.

However, the surgery is not limited to new injuries. Cook believes in select cases the procedure might help older adults who experienced damaged knees years before. In addition, there have been no major side effects reported from implantation of the scaffold. Currently, the implants are being used in rotator cuff injuries, skin grafts and bladder reconstruction in humans.

Meniscus Transplantation Post-Operative Physical Therapy Protocol

Meniscus Transplantation

Post-Operative Physical Therapy Protocol



General Considerations:

-Partial weight-bearing status for 4 weeks post-op. 10-20% toe-touch for 1-2 weeks, progress as tolerated.
-Most patients will be in a hinged rehab brace locked in full extension for 4 weeks post-op unless otherwise indicated.
-Regular assessment of gait to avoid compensatory patterns.
-Regular manual mobilizations to surgical wounds and associated soft tissue to decrease the incidence of fibrosis.
-No resisted leg extension machines (isotonic or isokinetic).
-No high impact or cutting / twisting activities for at least 4 months post-op.
-M.D. follow-up visits at Day 1, Day 8-10, 1 month, 4 months, 6 months, and 1 year post-op.
-During the first 4 weeks: TWICE PER DAY: Without brace and seated with feet off the ground, gently bend knee back as tolerated BUT NO MORE THAN 90 DEGREES for a good knee stretch without increase in pain. Relax knee and stretch for 60 seconds.

Week 1:
-M.D. visit day 1 post-op to change dressing and review home program.
-Icing and elevation regularly. Aim for 5x per day, 15-20 minutes each time. For ice machine: use as directed.
-Exercises:

1) straight leg raise exercises (lying, seated, and standing): quadriceps/adduction/abduction/gluteal sets;
2) twice daily passive and active range of motion exercises;
3) theraband calf presses;
4) well-leg stationary cycling;
5) upper body training; and
6) core/trunk training.

-Soft tissue treatments to musculature for edema and pain control.
-Manual daily patella glides up/down/side to side by therapist and patient.

Weeks 2 - 4:
-M.D. visit at 8 - 10 days for suture removal and check-up.
-GENTLE and BRIEF pool / deep water workouts after the first 8-10 days and with the use of a brace. No more than 30 minutes per workout; no more than 3 workouts per week.
-Continue with pain control, gentle range of motion, and soft tissue treatments.

Weeks 4 - 6:
-M.D. visit at 4 weeks post-op, will progress to full weight bearing and discontinue use of rehab brace.
-Increase stretching and manual treatments to improve knee range of motion. Extension should be full, and flexion should be near 100 degrees.
-Incorporate functional exercises (i.e. partial squats, calf raises, mini-step-ups, light leg pressing, proprioception).
-Stationary bike and progressing to road cycling as tolerated.
-Slow walking on treadmill for gait training (preferably a low-impact treadmill).
-Gait training to normalize movement patterns.

Weeks 6 - 8:
-Increase the intensity of functional exercises (i.e. cautiously increase depth of closed-chain exercises., Shuttle/leg press). Do not overload closed- or open-chain exercises.
- Continue to emphasize normal gait patterns.
-Range of motion: extension full, and flexion to 120 degrees.

Weeks 8 - 12:
-Add lateral training exercises (side-step ups, Theraband resisted side-stepping, lateral stepping).
-Introduce more progressive single leg exercise.
-Patients should be pursuing a home program with emphasis on sport/activity-specific training.
-Range of motion should be near normal.

Weeks 12-16:
-Low-impact activities until 16 weeks.
-Increasing intensity of strength and functional training for gradual return to activities.

Meniscus Transplantation

Meniscus Transplantation

What is Meniscus Transplantation?

The meniscus is the soft, fibrous shock absorber that rests in the knee between the femur and the tibia. When it is removed or worn-out, pain and arthritis can develop. Meniscus transplantation involves taking a meniscus from a cadaver (someone who is recently deceased, otherwise known as "allograft" tissue) and transplanting it to the patient, sort of like changing shock absorbers in a car. The meniscus is tested for contamination, and is then frozen. If the contamination-test results are clean, the tissue is provided to surgeons for meniscus transplantation. The technique involves an arthroscopic (minimum incision - microscopic sugery ) procedure.


Who can benefit from Meniscus Transplantation?

Patients with joint pain are the most common candidates. In older patients, we replace the meniscus to diminish pain, and to delay the time before a partial or complete joint replacement is required. In younger patients who have lost the cartilage (usually due to sports or traumatic injuries to the knee), we replace the meniscus to protect the joint for the future.What are the success rates of Meniscus Transplantation? Success rates are highest in the youngest patients with the healthiest joints. However, pain can also be diminished in older patients, even those with severe arthritis. Exact survival data for our patients with the meniscus transplants is currently being evaluated.


What are the potential complications of Meniscus Transplantation?

The most common problem has been partial re-tearing of the transplanted meniscus, which has required surgical repair (suturing), and rarely, a complete replacement. Rejection of the meniscus has not been seen in our patients, and is only reported worldwide in a few cases.Can infection from the Meniscus Allograft occur?Yes it can, despite comprehensive contamination testing performed prior to transplantation. We additionally sterilize our grafts with alcohol at the time of surgery. Although unlikely, a rare virus or bacteria could potentially survive.

Meniscus Injury Prevention

Meniscus Injury Prevention

Although it is important to be able to treat meniscus injury, prevention should be your first priority. So what are some of the things you can do to help prevent a meniscus injury?

Warm Up properlyA good warm up is essential in getting the body ready for any activity. A well-structured warm up will prepare your heart, lungs, muscles, joints and your mind for strenuous activity. If you would like to know more about the warm up, visit http://www.thestretchinghandbook.com/archives/warm-up.htm.

Avoid activities that cause painThis is self-explanatory, but try to be aware of activities that cause pain or discomfort, and either avoid them or modify them.

Rest and RecoveryRest is very important in helping the soft tissues of the body recover from strenuous activity. Be sure to allow adequate recovery time between workouts or training sessions.

Balancing ExercisesAny activity that challenges your ability to balance, and keep your balance, will help what is called, proprioception: - your body's ability to know where its limbs are at any given time.

Stretch and StrengthenTo prevent meniscus injury, it is important that the muscles around the knee be in top condition. Be sure to work on the strength and flexibility of all the muscle groups in the leg.

FootwearBe aware of the importance of good footwear. A good pair of shoes will help to keep your knees stable, provide adequate cushioning, and support your knees and lower leg during the running or walking motion.

StrappingStrapping, or taping can provide an added level of support and stability to weak or injured knees.