P117 - An Analysis of Medial Meniscal Allograft Size Discrepancies Between Patient and Donor Populations
- J. Grammens (Wilrijk, BE)
- J. Grammens (Wilrijk, BE)
- S. Tabbaa (Flagstaff, US)
- J. Pace (Farmington, US)
- R. Frank (Denver/Aurora, US)
- J. Vanlommel
- A. Van Haver (Antwerp, BE)
- P. Verdonk (Gent-Zwijnaarde, BE)
Abstract
Purpose
Recently, specific morphological characteristics of the knee (small medial femoral condyle) have been identified and linked to medial compartment pathology, such as early osteoarthritis (OA). A comparison of anthropometrics and meniscus sizes between medial meniscus allograft transplantation (mMAT) patients and medial meniscus donors might give further insights. We hypothesize that patients with medial pathology are subject to a smaller medial compartment resulting in higher pressures (=force/area).
Methods and Materials
A tissue bank was queried for anthropometrics and medial meniscus size, for both mMAT patient (N=291) and donor (N=1410) pools. The anthropometrics included sex, body mass and height. Two new ratios were introduced: (1) the body mass to meniscus size index (BMMI, kg/cm2) and (2) the height to meniscus index (HMI, cm/cm2) are the ratios of the body mass or height to the estimated meniscus area. Normalising for body mass and height, these ratios allow for comparison independent of anthropometric differences.
Results
Both male and female mMAT patients had a smaller medial meniscus width (p=0.0015) and length (p=0.0001) than donors. The estimated meniscus area was ca. 9% and 8% lower on average for male and female populations (p<0.0001).
In general, patients were more athletically built than donors (Fig. 1): male patients were taller (p=0.0004) and heavier (p=0.0394), while female patients were taller (p=0.008) and lighter (p=0.0166). In the male group, BMMI (p<0.0001; +13%) and HMI (p<0.0001; +9%) were higher for patients versus donors, which is strongly indicating more pressure per surface area unit. As female patients were higher but lighter than donors, BMMI was similar while HMI was significantly higher (p<0.0001; +10%).
Conclusion
This study confirms that mMAT patients are characterised by a smaller medial compartment. It strengthens the concept that early medial wear and symptoms might be explained by a smaller medial compartment. Future morphology studies might identify post-meniscectomy patients at risk for early medial OA.