IIIIII1IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII1IIIIIIIIIIIIIIIIIIIII
United States Patent m
Mehdian
US005217497A
[ii] Patent Number: [45] Date of Patent:
[54] APPARATUS FOR USE IN THE
TREATMENT OF SPINAL DISORDERS
[76] Inventor: Seyed M. H. Mehdian, Princess Elizabeth Orthopaedic Hospital, Wonford Road, Exeter, EX2 4UE, Devon, England
[21] Appl. No.: 725,588
[22] Filed: Jul. 3,1991
[30] Foreign Application Priority Data
Jul. 4, 1990 [GB] United Kingdom 9014817
[51] Int. CI.' A61F 2/44; A61B 17/00
[52] U.S. CI 623/17; 606/61;
606/69; 606/80
[58] Field of Search 623/17; 606/61, 69,
606/80
[56] References Cited
U.S. PATENT DOCUMENTS
3,604,487 9/1971 Gilbert 145/50 D
3,997,138 12/1976 Crock et al 606/61
4,782,833 11/1988 Einhorn et al 606/80
5,005,562 4/1991 Cotrel 128/69
FOREIGN PATENT DOCUMENTS
0151892 11/1984 European Pat. Off. .
2642643 2/1989 European Pat. Off. .
0346521 12/1989 European Pat. Off. .
0348272 12/1989 European Pat. Off. .
3916198 11/1990 Fed. Rep. of Germany .
2624720 6/1989 France .
2173104 10/1986 United Kingdom .
2223406 4/1990 United Kingdom .
Primary Examiner—Randall L. Green
Assistant Examiner—Debra S. Brittingham
Attorney, Agent, or Firm—Marshall, O'Toole, Gerstein,
Murray, Borun
[57] ABSTRACT
An implant (10) for use in fixing one segment of a spinal column to another segment thereof by means of at least one rod member, comprises a screw member (11) for insertion in the pedicle of a segment of a spinal column and having an enlarged diameter head (13) with an open ended transverse slot (16) to receive a fixing rod member (20), and clamp means having a screw threaded connection with the head (13) of the screw member (11) and having a clamping portion fitting around the outside of the head (13) of the screw member (11) for engaging a fixing rod member (20) inserted in the transverse slot (16) of the screw member (11) and clamping it therein. The clamp means comprises a collar (14) around a reduced diameter portion (19) of the head (13) and a clamping screw (15) having a threaded shank (18) inserted in a threaded counterbore (17) in the head (13) and having a flanged head (22) for engagement with the collar (14). The axial length of the shank (18) is less than the axial length of the collar (14) whereby a rod member (20) can be clamped by the collar (14) without being engaged by the shank (18). Ancillary instruments for use with the implant system include a center punch (40) for locating a hole to be drilled in a pedicle for insertion of a screw member (11), and a screw driver (50) for holding and inserting a screw member (11) into a drilled hole in a pedicle.
12 Claims, 5 Drawing Sheets
