Commonly Asked Questions
Answers From The Stone Clinic
What is a Meniscus?
The meniscus is the soft, fibrous shock absorber that rests in the knee between the femur and the tibia. When it is removed, pain and arthritis can develop.
What is Meniscus Allograft Transplantation?
Meniscus allograft transplantation involves taking a meniscus from a cadaver (some one who has just died). The meniscus is tested to ensure that it is not contaminated and then frozen. When all of the tests are negative for contamination, it is provided to surgeons for meniscus transplantation. The technique of transplantation involves an arthroscopic outpatient surgery (www.stoneclinic.com/menre.htm).
How Long Has Meniscus Allograft Replacement Been in Use?
Meniscus allograft transplantation was first performed in humans at the turn of the century, but the cases by Milachowski in 1986 stimulated renewed interest in the field. Our animal replacement experience started in 1986 and human meniscus implants using the first collagen meniscus reconstruction device in 1991. Complete allograft transplantation procedures at The Stone Clinic in San Francisco started in 1997.
Who Can Benefit?
Patients with joint pain after having previously lost their meniscus cartilage are our most common candidates. In older people, we place a meniscus in order to diminish pain and to delay the time when a partial or complete joint replacement would be required. In young people who have lost the cartilage usually due to sports, we place a meniscus to protect their joint for the future.
What are the Success Rates and the Problems?
Success rates are highest in the youngest patients with the healthiest
joints of course. However, pain can also be diminished in older patients
with arthritis. Exact survival data for our patients with the meniscus transplants
is currently being evaluated and is posted at http://www.stoneclinic.com/meniscus_latest.htm.
The most common problem has been partial re-tearing of the transplanted
meniscus which has required surgical suturing (repair), and rarely, complete
replacement. Rejection of the meniscus has not been seen in our patients
and only reported worldwide in a few cases.
Can Infection from the Allograft Occur?
Yes it can despite all testing. We secondarily sterilize our grafts with alcohol at the time of surgery. However, a rare virus or bacteria could potentially survive.
What is the Recovery Time and Rehabilitation Program?
• Partial weight-bearing status for 4 weeks
• Most patients will be in a hinged rehab brace locked in full extension
for 4 weeks
• No resisted leg extension machines (isotonic or isokinetic).
• No high impact or cutting/twisting activities for at least 4 months
post-op.
For the complete 16-week rehabilitation protocol, please see http://www.stoneclinic.com/meniscus_pt.htm
Related Publications:
1. “Meniscus Allograft Survival in Patients with Moderate to Severe
Unicompartmental Arthritis: A 2- to 7-Year Follow-up.” Stone KR, Walgenbach
AW, Turek TJ, Freyer A, Hill M. Arthroscopy: The Journal of Arthroscopic
and Related Surgery, Vol 22, No 5 (May), 2006: pp 469-478.
2. “Meniscal Allografting: The Three-Tunnel Technique.” Stone
KR, Walgenbach AW. Arthroscopy: The Journal of Arthroscopic and Related Surgery,
April 2003.
3. "Current and Future Directions for Meniscus Repair and Replacement." Stone
KR. Clinical Orthopaedics, 367:S273-280, October 1999.
4. "Meniscus Replacement." Stone KR. Clinics in Sports Medicine,
Vol. 15, No 3, pg. 557-571, July 1996.
5. "Replacement of the Irreparably Injured Meniscus." Rodkey WG,
Stone KR, Steadman JR. Sports Medicine and Arthroscopy Review, Vol. 1, No.
2, pg. 168-176, 1993.
6. "Surgical Technique of Meniscal Replacement." Stone KR. Arthroscopy:
The Journal of Arthroscopic & Related Surgery, Vol 9, pg. 234-237, April
1993.
The Stone 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.
How do I find out if I am a candidate for this procedure?
We would be pleased to help you. We usually need to see the x-rays, MRI and an exam to advise you properly.