Anti-backout arthroscopic uni-compartmental prosthesis
An improved uni-compartmental implant has a shaft having a proximal end attached to a head and a distal end, and one or more raised portions spaced apart along the shaft to resist back-out. The length between the head and distal end is preferably less than 50 mm, the distal end of the shaft has a diameter on the order of 2 to 3 mm, the proximal end of the shaft has a diameter on the order of 2 to 4 mm, and the head has a diameter ranging from 4 mm or less to 20 mm or more, making the device suitable for knee arthroscopy and other applications.
1. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant;
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and
wherein the implant has a single, tapered shaft having a central longitudinal axis.
2. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant;
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and wherein:
the implant has a single, tapered shaft having a central longitudinal axis; and
a plurality of separate raised portions spaced apart along the shaft to resist back-out.
3. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant;
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and wherein:
the implant has a single, tapered shaft having a central longitudinal axis; and
a plurality of separate raised portions spaced apart along the shaft to resist back-out, each raised portion forming a continuous, uninterrupted band extending outwardly from the shaft.
4. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant;
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and wherein:
the implant has a single, tapered shaft having a central longitudinal axis;
a plurality of separate raised portions spaced apart along the shaft to resist back-out, each raised portion forming a continuous, uninterrupted band extending outwardly from the shaft; and
each raised portion lying on a separate plane perpendicular to the longitudinal axis and becoming successively smaller from the proximal end to the distal end.
5. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant;
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and
wherein the length of the implant is less than 50 mm.
6. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant;
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and
wherein the shaft has a diameter on the order of 2 to 4 mm.
7. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant,
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and
wherein the head is ceramic.
8. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant;
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and
wherein the head is constructed of a chrome-cobalt alloy or other bio-compatible alloy.
9. An arthroscopic surgical procedure for treating a defect in a knee joint having a femoral side with medial and lateral condylar protrusions on respective sides of a patellofemoral groove and a tibial side with a platform against which the condylar protrusions articulate, the method comprising the steps of:
identifying a region of eburnated bone associated with a knee joint;
measuring the region;
providing an implant having a shaft and a head with dimensions corresponding to the measured region, the head having a first side attached to the shaft and an opposing second side having a convex outer surface;
reaming a central portion of the region to a specific depth corresponding to the shaft of the implant;
over-reaming with a secondary reamer corresponding to the size of the head of the implant;
press fitting or cementing the implant into the reamed and over-reamed portion of the defect; and
wherein the head has a diameter ranging from 2 mm to 20 mm.