Can we predict the graft diameter for autologous hamstring in anterior cruciate ligament reconstruction?

To achieve in the reconstruction of the anterior cruciate ligament a graft with strength, tension and low comorbidity is fundamental. An emerging concept is that a graft diameter of less than 7mm carries a greater risk of re-rupture and instability. Consequently, different methods are being sought to predict intra-surgical size. The objective is to predict the size of the hamstring graft by measuring the area of the semitendinous and gracilis tendon with magnetic resonance imaging (MRI).

We carried out an observational retrospective study of 56 patients. They underwent anterior cruciate ligament reconstruction with 4-GST hamstring graft. The parameters evaluated were anthropometric data, hamstring graft diameter, area of gracilis and semitendinosus tendon in MRI. The measurements were made by three independent evaluators.

The mean diameter of the intrasurgical graft was 8.46mm, in the MRI the area of the gracilis was 8,875mm and the semitendinosus area was 13,068mm. Their mean was 22.12 for the automatic measurement and 21.53 for the manual measurement. The interobserver correlation was regular for the automatic measurement (ICC = 0.595) and low for the manual measurement (ICC = 0.446). The result of the intraobserver correlation was excellent (ICC = 0.917). We did not obtain a statistical correlation between the measurement of areas and the increase of the graft diameter (R = 0.069, P = .63).

We determined with our results that the intrasurgical graft size is not predictable with the measurement of the area of the gracilis and semitendinosus tendon on the MRI.