First experiences with a Collagen Meniscus Implant
Vaeckenstedt J. (a), Wirz D. (b), Herr A. (a), Friederich N.F. (a)
a: Kantonsspital Bruderholz, Dep. of Orthopaedics and Traumatology, 4101 Bruderholz, Switzerland
b: Laboratory for Orthopaedic Biomechanics, University of Basle, Felix Platter-Spital, 4012 Basle, Switzerland
Purpose: A collagen based material for meniscal regeneration was used as a scaffold which is be implantable, bioresorbable and biocompatible. This scaffold was designed, developed and then tested in two clinical studies by KR Stone, JR Steadman and WG Rodkey (1,2). They emphasized, that this scaffold supports new tissue regeneration and is resorbable. The new tissue appears to function similar to normal meniscal
tissue. Our departement was enrolled in a European multicenter trial (12 hospitals).
Material and Methods: The including criterias for patients in this multicenter study were patients under 50 years, suffering from a meniscal tear unsuitable for suturing, having a stable or stabilized knee and no relevant cartilage damage. 5 scaffolds in 5 patients were implanted between 2/1997 and 8/1998. Until 12/1998 no re-look arthroscopy was done. A clinical follow-up was done after 3 months for 1 patient, 6 months for 2 patients and 12 months for 2 patients.
Follow up included a thorough clinical examination and radiographic and MRI evaluation of the index knee.
Clinical Results: 1 patient had no complains (after 3 months) and a full range of motion. 1 patient had no benefit by this procedure after 12 months: persistent pain in the medial knee compartment, however full range of motion.
The other three patients (1 after 12 months and 2 after 6 months) had a full range of motion, 2 returned to daily
activities with mild pain in the medial compartment of the knee, 1 patient was fully active however with severe pain in the medial compartment.
Because of the low number of patients, no statistical analysis is allowed.
Discussion: An in vitro study with the collagen meniscus implant (CMI) was performed by the Laboratory for Orthopaedic Biomechanics in Basle (3). Although the CMI was not designed to take up load already at day one after implantation, the aim of this testing was to look, whether after medial meniscectomy and implanting a collagen meniscus prothesis in vitro the natural pressure distribution in human cadaveric knee joints can be restored.
In vitro-tests showed that after a simulated "day one" after implantation of a CMI and after total meniscectomy, the load transmission between the femoral and tibial cartilage was the same. Whether this will change and becomes better after biological repopulation of the scaffold by host tissue is still to be studied.
The multicenter study at 12 hospitals is still ongoing. The results suggest, that the collagen meniscal implant may be able to replace meniscal tissue after biological repopulation.
Literature:
In vitro and in vivo studies evaluated clinically, histologically and biochemically.
Am J Sports Med, 20(2):104-11 1992 Mar-Apr
Analysis of preliminary data.
an in vitro study with collagen meniscus implants. Oral presentation EFORT, Brussels, June 3-8, 1999