Patent ID: 8920428

Claim:
Surgical instrumentation specific to a patient ( 1 ; 1 ′) for preparing a bone (B) of the patient, the instrumentation comprising a patient-specific block ( 10 ; 10 ′) delimiting a fixed supporting surface ( 12 ) on the bone (B), which is shaped so as to be specifically fitted to this bone (B), and including a main portion ( 20 ) which partly delimits the fixed supporting surface ( 12 ) and which delimits at least two primary orifices ( 27 , 28 ) for respectively letting through a primary pin ( 61 , 62 ), these primary orifices passing through the block ( 10 ; 10 ′) between the supporting surface and an opposite surface ( 14 ) of the block, the instrumentation ( 1 ; 1 ′) further comprising: a secondary portion ( 30 ) which belongs to the block ( 10 ; 10 ′), which partly delimits the supporting surface ( 12 ) and which includes at least two secondary orifices ( 37 , 38 ) for respectively letting through a bone preparation tool ( 63 , 64 ), such as a boring bit or an anchoring pin, these secondary orifices crossing the block between the supporting surface and the opposite surface ( 14 ) of the block, and means ( 40 ; 140 ; 240 ; 340 ; 440 ; 540 ; 640 ; 740 ; 840 ; 940 ; 1040 ; 1140 ; 1240 ; 40 ′) for mechanically disengaging the secondary portion ( 30 ) with respect to the main portion ( 20 ), suitable for, while the main portion is attached onto the bone (B) by primary pins ( 61 , 62 ) having passed into the primary orifices ( 27 , 28 ), making the secondary portion ( 30 ) removable with respect to the main portion, wherein the mechanical disengagement means ( 40 ) comprise at least one patient-specific cavity ( 43 , 44 ), which extends through the block ( 10 ) between the main portion ( 20 ) and the secondary portion ( 30 ), along a geometrical envelope of the fixed supporting surface ( 12 ).