Studies
SURGICAL TECHNIQUE OF MENISCAL REPLACEMENT IN ARTHRITIC KNEES
K.R. Stone, M.D., A. Walgenbach, R.N., N.P., M.S.N.
The Stone Foundation for Sports Medicine and Arthritis Research at
The Stone Clinic, 3727 Buchanan Street, San Francisco CA 94123
kstonemd@stoneclinic.com
www.stoneclinic.com
Objectives: Meniscal cartilage replacement by allograft, prosthesis, and regeneration scaffolds has advanced from the laboratory to clinical practice. Since the first reported human meniscal allograft was performed by Michalowski in 1986, approximately 4,000 meniscal replacements have been performed in the United States. Most have been performed in knees without arthritis. We hypothesized that meniscal replacement could augment standard chondroplasties in arthritic knees. In order to overcome difficulties with arthritic knee deformities and the paucity of surgical instrumentation, the authors developed a technique to aid placement and fixation of the meniscal allografts. This study is the first of a series that evaluates the technical difficulties and survivability of the implant in the arthritic knee. A second study will compare chondroplasty alone to chondroplasty plus meniscal allografting in the primarily unicompartmental arthritic knee.
Materials & Methods: All patients signed informed consents, underwent pre-operative exams, X-rays, MRI’s and completed pre- and post-operative Tegner, ADLS and WOMAC questionnaires at sequential follow-up intervals. The arthroscopic surgical implant procedure implements a three-tunnel technique to secure the anterior and posterior meniscal horns and posterior corner of the allograft. Additional stabilization of the implant is achieved through an inside-out suture technique, shown in the following figures:
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Results: At an average follow-up of 1.4 years (range 1 to 2.7 years) preliminary results from a 49 patient prospective study of patients with Grade IV arthritis show reduction in pain scores pre- to post-surgery of 5.4 to 4.5 (scale 1-10; 1 being no pain), and increases in activity levels from 1.4 to 1.9 (scale 1-3) (p<0.02). WOMAC, Tegner, and ADLS scores also showed improvement. The re-tear rate was 6 of 47 implants for this patient population.
Significance & Conclusions: Meniscal allografting can be successfully performed in arthritic knees, although with a 13% re-tear rate. The six implants tore at 1, 4, 10, 11, 14, and 24 months. The specific cause of the pain relief cannot be pinpointed due to the multiple concomitant procedures performed in these complex knees as well as participation of patients in a well-defined rehabilitation program. It is the authors impression, however, that meniscal transplantation in arthritic knees augments standard care, and leads to favorable outcomes in this evaluation period. A controlled, comparative study will be required to prove this clinical impression. Further segmentation of these results over time will help clarify the role of meniscal allografting in arthritic knees. Technical difficulties with implanting meniscal allografts in arthritic knees are diminished by this three-tunnel technique.