A method for forming a prosthetic base knit made of two parallel sheets of porous knits, namely a first sheet of porous knit and a second sheet of porous knit, said two parallel sheets being joined together in a discrete manner by a plurality of connecting porous knits spaced apart from each other, said method comprising knitting on a warp knitting machine comprising two needle-beds, a first needle-bed comprising a first guide bar B1, a second guide bar B2 and a third guide bar B3, and a second needle-bed comprising a fourth guide bar B4, a fifth guide bar B5 and a sixth guide bar B6, yarns of a biocompatible material threaded in said first, second, third, fifth and sixth guide bars, according to a defined pattern unit recurring as desired along a warp direction of the machine, said pattern unit corresponding to a total number of N courses ranging from 1 to N completed along said warp direction on each needle-bed, and according to a defined threading-in unit repeated along the width of the knitting machine, said threading-in unit corresponding to a total number T of needles along said width of the machine, N and T being each an integer equal or greater than 5, wherein i) for needles ranging from 1 to T and courses ranging from 1 to N, the knitting patterns followed by the first and second guide bars (B1, B2) produce on the first needle-bed said first sheet of porous knit under the form of a first bidimensional porous knit, and the knitting patterns followed by the fifth and sixth guide bars (B5, B6) produce on the second needle-bed said second sheet of porous knit under the form of a second bidimensional porous knit, and ii) for needles ranging from w to z, where 1≤w<z≤T and courses ranging from x to y, where 1≤x<y≤N, where w, x, y and z are integers, the knitting pattern followed by the third guide bar B3 produces a connecting porous knit joining said first sheet of porous knit to said second sheet of porous knit, under the form of a three-dimensional porous knit, made of yarns threaded in said third guide bar B3 crossing from the first needle-bed to the second needle-bed and vice-versa, characterized in that N being equal to 264, the knitting patterns followed by guide bars B1, B2, B3, B5 and B6 is the following, according to the ISO 11676 standard (publication year 2014): B1: (3-2-2-2/2-1-1-1/0-1-2-2)×88// B2: (2-3-3-3/3-4-4-4/5-4-3-3)×88// B3: (2-3-3-3/3-4-4-4/5-4-3-3)×36/ (2-3-3-2/3-4-3-2/5-4-4-5)×3/ (2-3-3-3/3-4-4-4/5-4-3-3)×49// B5: (2-2-1-0/1-1-1-2/1-1-1-0/1-1-1-2/4-4-6-7/6-6-6-5/6-6-6-7/6-6-6-5)×33// B6: (5-5-6-7/6-6-6-5/6-6-6-7/6-6-6-5/3-3-1-0/1-1-1-2/1-1-1-0/1-1-1-2)x33//. i) for needles ranging from 1 to T and courses ranging from 1 to N, the knitting patterns followed by the first and second guide bars (B1, B2) produce on the first needle-bed said first sheet of porous knit under the form of a first bidimensional porous knit, and the knitting patterns followed by the fifth and sixth guide bars (B5, B6) produce on the second needle-bed said second sheet of porous knit under the form of a second bidimensional porous knit, and ii) for needles ranging from w to z, where 1≤w<z≤T and courses ranging from x to y, where 1≤x<y≤N, where w, x, y and z are integers, the knitting pattern followed by the third guide bar B3 produces a connecting porous knit joining said first sheet of porous knit to said second sheet of porous knit, under the form of a three-dimensional porous knit, made of yarns threaded in said third guide bar B3 crossing from the first needle-bed to the second needle-bed and vice-versa, B1: (3-2-2-2/2-1-1-1/0-1-2-2)×88// B2: (2-3-3-3/3-4-4-4/5-4-3-3)×88// B3: (2-3-3-3/3-4-4-4/5-4-3-3)×36/ (2-3-3-2/3-4-3-2/5-4-4-5)×3/ (2-3-3-3/3-4-4-4/5-4-3-3)×49// B5: (2-2-1-0/1-1-1-2/1-1-1-0/1-1-1-2/4-4-6-7/6-6-6-5/6-6-6-7/6-6-6-5)×33// B6: (5-5-6-7/6-6-6-5/6-6-6-7/6-6-6-5/3-3-1-0/1-1-1-2/1-1-1-0/1-1-1-2)x33//.