Bone plate for epiphysiodesis
The present invention relates to a bone plate ( 1, 21 ) for epiphysiodesis, which has been advantageously improved to allow better articulation of the fixing screws engaged with the bone plate ( 1, 21 ), comprising: a first portion ( 4 ) and a second portion ( 6 ) joined by a connecting portion ( 5 ), intersected by a first ( 9 ) and a second opening ( 10 ), respectively, structured to receive the same number of fixing screws; the bone plate having a bilobal figure, such as an eight shape; at least one of said first ( 9 ) and second ( 10 ) openings comprising: a cup-shaped seat ( 12 ) for housing a fixing screw head in a tillable manner, and at least one recess ( 14 ″) which merges into the cup-shaped seat ( 12 ) expanding an exit section ( 12 b ) away from the connecting portion ( 5 ).
1. Bone plate for epiphysiodesis comprising: a first portion and a second portion structured to be fastened to epiphysis and metaphysis, respectively, of a long bone in a paediatric patient; said first and second portions being joined by a connecting portion structured to straddle a growth plate of said long bone; said first and said second portions being intersected by at least a first and at least a second opening, respectively, structured to receive fixing screws for fastening to said long bone; said bone plate having a bilobal figure, such as an eight shape; at least one of said first and second openings comprising: a cup-shaped seat for housing a head of said fixing screw in a tiltable manner, said cup-shaped seat having an entry section structured to allow insertion of the head of said fixing screw and an exit section of an at least locally smaller size compared to a respective size of said entry section so as to retain the head of said fixing screw; wherein the at least one of said first and second openings further comprises at least one recess which merges into the cup-shaped seat, expanding the exit section away from the connecting portion, and wherein said at least one recess takes form of a tilted hole with respect to a central axis of symmetry of said cup-shaped seat, wherein the tilted hole locally widens an outer periphery, opposite the connecting portion, of the exit section of said cup-shaped seat, and wherein the tilted hole extends from a merging point on said cup-shaped seat away from both the connecting portion and the entry section.
2. Bone plate according to claim 1 , wherein said at least one of said first and second openings further comprises a cylindrical through hole, which extends said cup-shaped seat beyond said exit section opening on a first surface of the bone plate opposite a second surface on which said cup-shaped seat opens.
3. Bone plate according to claim 1 , wherein said cup-shaped seat has a spherical inner shape, shaped to slidably house the head of the fixing screw which is also spherical.
4. Bone plate according to claim 1 , wherein said bone plate has a symmetrical structure, at least one of said first openings and at least one of said second openings being identical and opposite each other.
5. Bone plate according to claim 4 , wherein each of said first and said second portions has respectively two first openings and two second openings, said first and said second openings being aligned along transverse axes to a longitudinal extension of said bone plate.
6. Bone plate according to claim 5 , wherein said bilobal figure comprises a quatrefoil shape.
7. Epiphysiodesis kit comprising:
a bone plate for epiphysiodesis comprising: a first portion and a second portion structured to be fastened to epiphysis and metaphysis, respectively, of a long bone in a paediatric patient; said first and second portions being joined by a connecting portion structured to straddle a growth plate of said long bone; said first and said second portions being intersected by at least a first and at least a second opening, respectively, structured to receive two fixing screws for fastening to said long bone; said bone plate having a bilobal figure, such as an eight shape; at least one of said first and second openings comprising: a cup-shaped seat for housing a head of said fixing screw in a tiltable manner, said cup-shaped seat having an entry section structured to allow insertion of the head of said fixing screw and an exit section of an at least locally smaller size compared to a respective size of said entry section so as to retain the head of said fixing screw; wherein at least one of said first and second openings further comprises at least one recess which merges into the cup-shaped seat expanding the exit section away from the connecting portion, and wherein said at least one recess takes form of a tilted hole with respect to a central axis of symmetry of said cup-shaped seat, wherein the tilted hole locally widens an outer periphery, opposite the connecting portion, of the exit section of said cup-shaped seat, and wherein the tilted hole extends from a merging point on said cup-shaped seat away from both the connecting portion and the entry section;
said two fixing screws with said heads, which can be inserted into said cup-shaped seat in the tiltable manner and a shank which is at least partially threaded and structured to pass through said first or said second opening, respectively, to engage with epiphysis or metaphysis respectively of the patient.