Screw and driver for securing a bone block

• US 5,423,819 A
• Filed: 08/17/1992
• Issued: 06/13/1995
• Est. Priority Date: 02/06/1989
• Status: Expired due to Fees

• Current Assignee: Smith & Nephew Incorporated (Smith & Nephew PLC)
• Original Assignee: American Cyanamid Co (Pfizer Inc.)
• Inventors: Bourque, Bernard J., Small, Alan A.
• Primary Examiner(s): Hafer, Robert A.
• Assistant Examiner(s): HANLON, BRIAN EMMETT
• Application Number:
  US07/931,167
• Time in Patent Office: 1,030 Days
• Field of Search: 606/60, 606/64, 606/65, 606/72, 606/73, 606/104, 411/394, 411/395, 411/403, 411/404, 411/405, 411/407, 411/408, 411/410
• US Class Current: 606/232
• CPC Class Codes: A61B 17/861 specially shaped for gripping driver
• CPC Class Codes: A61B 17/864 hollow, e.g. with socket or cannulated
• CPC Class Codes: A61B 17/8888 at its central region
• CPC Class Codes: B25B 23/108 the driving bit being a Philips type bit, an Allen type bit or a socket
• CPC Class Codes: H04L 25/065 Binary decisions
• CPC Class Codes: H04L 25/066 Multilevel decisions, not including self-organising maps

Abstract

A screw and driver combination designed so that the screw is releasably axially couplable with the driver and so that the screw is positively rotatably engageable with the driver. The screw comprises an axial bore of circular cross section and a counterbore of polygonal cross section. The driver comprises a radially-compressible front portion sized to engage the axial bore of the screw with a minor spring interference fit and an intermediate portion sized to positively rotatably engage the counterbore of the screw.

Claims

1. A process of securing a tendon within a hole in a bone comprising:

providing a threaded screw and a driver, said threaded screw including;

(a) first and second ends,

(b) an axial bore coupled with said first end, said axial bore having a circular cross section of selected diameter, and

(c) a counterbore coupled with said first end and coaxial with said axial bore, said counterbore having a selected length and a polygonal cross section of selected configuration and dimension, and

wherein said threaded screw is turned by inserting a cylindrical front portion of said driver into said axial bore of said threaded screw and an elongate intermediate portion of said driver into said counterbore of said threaded screw, said driver comprising;

(a) an elongate shaft having a front end,

(b) said elongate intermediate portion having first and second ends, said second end of said intermediate portion being fixedly attached to said front end of said shaft, said intermediate portion having a polygonal cross section configured and dimensioned (i) so that said intermediate portion of said driver can be inserted into said counterbore of said screw with a sliding fit, and (ii) so that when said intermediate portion of said driver is inserted in said counterbore of said screw said intermediate portion drivingly engages said counterbore of said screw so that rotational drive can be transmitted from said driver to said screw, and

(c) said cylindrical front portion having a back end and a front end, said back end of said front portion being fixedly attached to said first end of said intermediate portion, said front portion comprising compression means for permitting said front portion to be compressed radially into a compressed state, the design and diameter of said cylindrical front portion being chosen (i) so that insertion of said front portion into said bore of said screw will cause said front portion of said driver to be compressed into said compressed state, and (ii) so that when said front portion of said driver is inserted in said bore of said screw said front portion will engage said bore with a spring interference fit, whereby said front portion of said driver cannot be removed from said bore of said screw except when a selected axial force is applied to said front portion of said driver;

drilling a hole in said bone;

fitting a bone plug to which said tendon is attached into said hole;

inserting the front end of said threaded screw into said hole, said screw being positioned between said bone plug and the wall of said hole; and

turning said threaded screw utilizing said driver, whereby said threaded screw engages said bone plug and adjacent portions of bone and pulls the screw into the bone and bone plug to act as a wedge forcing said bone plug into tight frictional engagement with the wall of said hole.