Patents by Inventor Chitranjan S. Ranawat
Chitranjan S. Ranawat has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 9861488Abstract: A knee joint prosthesis which comprises a tibial component (4, 6) and a femoral component (2). The femoral component has condyles (14, 16) which act against the tibial component, directly or indirectly, during flexing of the knee. A cam (20) on the femoral component acts against a post (26) on the tibial component at high flex angles. The surface of the post which is contacted by the cam at high flex angles is convex when the post viewed generally perpendicular to the tibial bone contact and bearing surfaces, and the femoral bearing surface which is provided by the cam, where it contacts the convex surface of the post at high flex angles, is locally concave (32) when viewed along the surface of the post which contacts the cam so that the area of contact between the post and the cam is greater at high flex angles than at lower flex angles.Type: GrantFiled: June 6, 2016Date of Patent: January 9, 2018Assignees: DePuy International, Ltd.Inventors: Richard Farrar, Liam Rowley, Andrew Cohen, James Brooks, Chitranjan S. Ranawat
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Publication number: 20160278931Abstract: A knee joint prosthesis which comprises a tibial component (4, 6) and a femoral component (2). The femoral component has condyles (14, 16) which act against the tibial component, directly or indirectly, during flexing of the knee. A cam (20) on the femoral component acts against a post (26) on the tibial component at high flex angles. The surface of the post which is contacted by the cam at high flex angles is convex when the post viewed generally perpendicular to the tibial bone contact and bearing surfaces, and the femoral bearing surface which is provided by the cam, where it contacts the convex surface of the post at high flex angles, is locally concave (32) when viewed along the surface of the post which contacts the cam so that the area of contact between the post and the cam is greater at high flex angles than at lower flex angles.Type: ApplicationFiled: June 6, 2016Publication date: September 29, 2016Inventors: Richard Farrar, Liam Rowley, Andrew Cohen, James Brooks, Chitranjan S. Ranawat
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Patent number: 9445901Abstract: A device for releasing a therapeutic agent in the body space in the form of a prosthetic joint implant having a first portion such as a stemmed portion for contacting bone tissue in an intramedullary canal of a long bone. The implant has a second portion which extends into the body space such as a joint space. The joint component contains a reservoir filled with a bioabsorbable/resorbable polymer which includes a therapeutic agent. The reservoir is open or in contact with the joint space as the body fluid diffuses in and out of the polymeric device it carries the drug into the joint space.Type: GrantFiled: March 12, 2003Date of Patent: September 20, 2016Inventors: Deger C. Tunc, Chitranjan S. Ranawat, Amar S. Ranawat
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Patent number: 9408617Abstract: A patient-specific acetabular guide for use in orienting an acetabular component with respect to an acetabulum of a patient as part of a surgical procedure includes a body having a bottom contact surface that has a portion that is shaped and configured to initimately receive and interlockingly mate with an acetabular notch of the patient's acetabulum in accordance with a three-dimensional image of the acetabulum of the specific patient. The three-dimensional image can be in the form of a three-dimensional virtual model of the patient's acetabulum that is constructed at least in part on 3D image data of the pelvic region of the patient.Type: GrantFiled: March 5, 2015Date of Patent: August 9, 2016Assignee: NEW YORK SOCIETY FOR THE RUPTURED AND CRIPPLED MAINTAINING THE HOSPITAL FOR SPECIAL SURGERYInventors: Chitranjan S. Ranawat, Joseph D. Lipman, Morteza Meftah, David Mayman
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Patent number: 9358118Abstract: A knee joint prosthesis which comprises a tibial component (4, 6) and a femoral component (2). The femoral component has condyles (14, 16) which act against the tibial component, directly or indirectly, during flexing of the knee. A cam (20) on the femoral component acts against a post (26) on the tibial component at high flex angles. The surface of the post which is contacted by the cam at high flex angles is convex when the post viewed generally perpendicular to the tibial bone contact and bearing surfaces, and the femoral bearing surface which is provided by the cam, where it contacts the convex surface of the post at high flex angles, is locally concave (32) when viewed along the surface of the post which contacts the cam so that the area of contact between the post and the cam is greater at high flex angles than at lower flex angles.Type: GrantFiled: July 19, 2013Date of Patent: June 7, 2016Assignees: DePuy International, Ltd.Inventors: Richard Farrar, Liam Rowley, Andrew Cohen, James Brooks, Chitranjan S. Ranawat
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Publication number: 20150238272Abstract: A patient-specific acetabular guide for use in orienting an acetabular component with respect to an acetabulum of a patient as part of a surgical procedure includes a body having a bottom contact surface that has a portion that is shaped and configured to initimately receive and interlockingly mate with an acetabular notch of the patient's acetabulum in accordance with a three-dimensional image of the acetabulum of the specific patient. The three-dimensional image can be in the form of a three-dimensional virtual model of the patient's acetabulum that is constructed at least in part on 3D image data of the pelvic region of the patient.Type: ApplicationFiled: March 5, 2015Publication date: August 27, 2015Inventors: Chitranjan S. Ranawat, Joseph D. Lipman, Morteza Meftah, David Mayman
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Patent number: 9011456Abstract: A patient-specific acetabular guide for use in orienting an acetabular component with respect to an acetabulum of a patient as part of a surgical procedure includes a body having a bottom contact surface that has a portion that is shaped and configured to initimately receive and interlockingly mate with an acetabular notch of the patient's acetabulum in accordance with a three-dimensional image of the acetabulum of the specific patient. The three-dimensional image can be in the form of a three-dimensional virtual model of the patient's acetabulum that is constructed at least in part on 3D image data of the pelvic region of the patient.Type: GrantFiled: August 16, 2012Date of Patent: April 21, 2015Assignee: New York Society for the Ruptured and Crippled Maintaining the Hospital for Special SurgeryInventors: Chitranjan S. Ranawat, Joseph D. Lipman, Morteza Meftah, David Mayman
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Publication number: 20140343685Abstract: A femoral component for a hip prosthesis has a proximal end for disposition at a superior position in a femur and a distal end opposite the proximal end. The femoral component has opposite medial and lateral sides and opposite anterior and posterior faces extending between the medial and lateral sides. At least a proximal part of the femoral component has a first superior-to-inferior taper so that a medial to lateral dimension decreases gradually from the proximal end toward the distal end, a second superior-to-inferior taper so that an anterior to posterior dimension of the femoral component decreases gradually from the proximal end toward the distal end and a lateral-to-medial taper so that an anterior to posterior dimension of the femoral component decreases gradually from the lateral side toward the medial side.Type: ApplicationFiled: May 20, 2014Publication date: November 20, 2014Inventors: Chitranjan S. Ranawat, Amar S. Ranawat, Leslie L. Jacobs, Morteza Meftah
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Publication number: 20130310944Abstract: A knee joint prosthesis which comprises a tibial component (4, 6) and a femoral component (2). The femoral component has condyles (14, 16) which act against the tibial component, directly or indirectly, during flexing of the knee. A cam (20) on the femoral component acts against a post (26) on the tibial component at high flex angles. The surface of the post which is contacted by the cam at high flex angles is convex when the post viewed generally perpendicular to the tibial bone contact and bearing surfaces, and the femoral bearing surface which is provided by the cam, where it contacts the convex surface of the post at high flex angles, is locally concave (32) when viewed along the surface of the post which contacts the cam so that the area of contact between the post and the cam is greater at high flex angles than at lower flex angles.Type: ApplicationFiled: July 19, 2013Publication date: November 21, 2013Applicant: DePuy International, Ltd.Inventors: Richard Farrar, Liam Rowley, Andrew Cohen, James Brooks, Chitranjan S. Ranawat
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Patent number: 8500817Abstract: A knee joint prosthesis which comprises a tibial component (4, 6) and a femoral component (2). The femoral component has condyles (14, 16) which act against the tibial component, directly or indirectly, during flexing of the knee. A cam (20) on the femoral component acts against a post (26) on the tibial component at high flex angles. The surface of the post which is contacted by the cam at high flex angles is convex when the post viewed generally perpendicular to the tibial bone contact and bearing surfaces, and the femoral bearing surface which is provided by the cam, where it contacts the convex surface of the post at high flex angles, is locally concave (32) when viewed along the surface of the post which contacts the cam so that the area of contact between the post and the cam is greater at high flex angles than at lower flex angles.Type: GrantFiled: February 9, 2004Date of Patent: August 6, 2013Inventors: Richard Farrar, Liam Rowley, Andrew Cohen, James Brooks, Chitranjan S. Ranawat
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Publication number: 20130046310Abstract: A patient-specific acetabular guide for use in orienting an acetabular component with respect to an acetabulum of a patient as part of a surgical procedure includes a body having a bottom contact surface that has a portion that is shaped and configured to initimately receive and interlockingly mate with an acetabular notch of the patient's acetabulum in accordance with a three-dimensional image of the acetabulum of the specific patient. The three-dimensional image can be in the form of a three-dimensional virtual model of the patient's acetabulum that is constructed at least in part on 3D image data of the pelvic region of the patient.Type: ApplicationFiled: August 16, 2012Publication date: February 21, 2013Applicant: NEW YORK SOCIETY FOR THE RUPTURED AND CRIPPLED MAINTAINING THE HOSPITAL FOR SPECIAL SURGERYInventors: Chitranjan S. Ranawat, Joseph D. Lipman, Morteza Meftah, David Mayman
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Publication number: 20090306785Abstract: A knee joint prosthesis which comprises a tibial component (4, 6) and a femoral component (2). The femoral component has condyles (14, 16) which act against the tibial component, directly or indirectly, during flexing of the knee. A cam (20) on the femoral component acts against a post (26) on the tibial component at high flex angles. The surface of the post which is contacted by the cam at high flex angles is convex when the post viewed generally perpendicular to the tibial bone contact and bearing surfaces, and the femoral bearing surface which is provided by the cam, where it contacts the convex surface of the post at high flex angles, is locally concave (32) when viewed along the surface of the post which contacts the cam so that the area of contact between the post and the cam is greater at high flex angles than at lower flex angles.Type: ApplicationFiled: February 9, 2004Publication date: December 10, 2009Inventors: Richard Farrar, Liam Rowley, Andrew Cohen, James Brooks, Chitranjan S. Ranawat
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Publication number: 20040180072Abstract: A device for releasing a therapeutic agent in the body space in the form of a prosthetic joint implant having a first portion such as a stemmed portion for contacting bone tissue in an intramedullary canal of a long bone. The implant has a second portion which extends into the body space such as a joint space. The joint component contains a reservoir filled with a bioabsorbable/resorbable polymer which includes a therapeutic agent. The reservoir is open or in contact with the joint space as the body fluid diffuses in and out of the polymeric device it carries the drug into the joint space.Type: ApplicationFiled: March 12, 2003Publication date: September 16, 2004Applicant: Howmedica Osteonics Corp.Inventors: Deger C. Tunc, Chitranjan S. Ranawat, Amar S. Ranawat, James Ronald Banks
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Patent number: 4822364Abstract: An elbow joint prosthesis having a metal humeral component, the head of which has flanges forming a recess in which a U-shaped plastic insert is nested. A boss projecting anteriorly from the head portion of a metal ulnar component is received within the insert with latero-medial clearance for laxity. A tubular plastic sleeve is received in axle holes in the ulnar boss and the legs of the plastic insert, and an axle spanning the flanges of the humeral component and extending through the sleeve bore connects the ulnar component to the humeral component for articulation. Clearance between the sleeve and the axle hole of the ulnar boss provides laxity up to nominal limits, beyond which elastic deformation of plastic at contact areas of the sleeve and insert restrains rotational and angular motions under supination, pronation and varus-valgus angulation of the arm, absorbing energy in the process.Type: GrantFiled: December 21, 1987Date of Patent: April 18, 1989Assignee: New York Society for the Relief of the Ruptured and Crippled, Maintaining the Hospital for Special SurgeryInventors: Allan E. Inglis, Chitranjan S. Ranawat, Albert H. Burstein
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Patent number: 4778475Abstract: A femoral component for a hip joint prosthesis comprises a proximal portion adapted to be received in the intertrochanteric region of a femur, a neck portion extending obliquely medially, anteriorly and superiorly from the proximal portion and adapted to be joined to a femoral head element, and a stem portion smoothly merging with and extending inferiorly from the proximal portion. The proximal portion has anterior and prosterior aspects that converge medially and inferiorly and intersect a rounded medial aspect oriented obliquely to the stem portion both anteriorly and medially, said aspects defining a generally wedge-shaped body adapted to engage the endosteal surfaces of the femur in the intertrochanteric region such that substantially all loads are transmitted from the component to the bone in the intertrochanteric region and load transfers through other surfaces are minimized.Type: GrantFiled: November 10, 1987Date of Patent: October 18, 1988Assignee: New York Society for the Relief of the Ruptured and CrippledInventors: Chitranjan S. Ranawat, Albert H. Burstein, Donald L. Bartel
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Patent number: 4714476Abstract: A wrist joint prosthesis comprises a metal radial component and a metal metacarpal component connected by a metal axle and providing triaxial motions that are comparable to those of the anatomical wrist joint and restraint of excessive motions. Energy is absorbed and shock loads are minimized by the interposition of a bearing member between the radial and metacarpal components and a bearing sleeve of polymeric material over the axle.Type: GrantFiled: January 27, 1987Date of Patent: December 22, 1987Assignee: New York Society for the Relief of the Ruptured and CrippledInventors: Chitranjan S. Ranawat, Lee R. Straub, Allan E. Inglis, Albert H. Burstein