referring now in more detail to the drawings in which like numerals indicate like parts throughout the several views , fig1 - 3 disclose a temporary knee implant 10 as it would be inserted at the location of the knee joint , between the femur 12 and the tibia 13 . the three drawings show the anterior , medial and posterior views , respectively , of the position of the human body . the temporary knee implant is inserted in the medullary cavities 15 and 16 of the femur and tibia , respectively . as best shown in fig4 , the temporary knee implant 10 includes an elongated femur rod 18 and a similar elongated tibia rod 19 . the femur rod includes a femur stem 20 and the tibia rod includes its tibia stem 21 and both include connector collars 22 and 23 , respectively . the femur connector collar 22 is mounted to the distal end of the femur stem 20 , and the tibia connector collar 23 is connected to the proximal end of the tibia stem . the collars 22 and 23 are disk - shaped , but may be of other shapes that provide similar functions . as illustrated in fig5 , the femur connector collar 22 and the tibia connector collar 23 include complementary connectors formed by interfitting shapes for aligning the femur stem 20 and the tibia stem 21 . the interfitting shapes may include a tapered femur locking pin 24 that protrudes beyond the femur connector collar 23 , and a tibia socket 25 formed in the tibia connector collar 23 that is tapered and sized and shaped to receive the femur locking pin 24 . when the femur rod and tibia rod are to be connected together , the femur locking pin 24 is aligned with and moved into tibia socket 25 , as shown in fig5 . the dimensions and shapes of the femur locking pin and the tibia socket are such that the tibia connector collar 23 is likely to become closely spaced from the femur connector collar 22 . the femur and tibia connector collars 22 and 23 provide opposed bearing surfaces 31 and 32 for use by the surgeon when the femur and tibia rods are to be connected , as illustrated in fig5 . the femur and tibia rods 18 and 19 may be coated with an antibiotic of choice by the surgeon , as indicated at 29 and 30 of fig6 and 7 . the antibiotic coatings 29 and 30 are applied to the femur and tibia stems 20 and 21 , preferably with the coating being uniformly applied along the full length of the femur and tibia stems . the antibiotic coatings 29 and 30 may be applied to the femur and tibia rods before the rods are connected together , as illustrated in fig6 . it is anticipated that the surgeon will select the femur and tibia rods of proper dimensions to fit the medullary cavities of the femur and tibia , even with the possibility that one medullary cavity might be of greater or lesser breadth than the other . further , the femur and tibia rods are of smaller breadth than the anticipated breadth of the medullary cavities of the femur and tibia so that when an antibiotic coating 29 is applied , the antibiotic coating tends to fill the space within the medullary cavities not occupied by the stems 20 and 21 of the femur and tibia . this permits the antibiotic coating to substantially fill and contact the facing surfaces of the medullary cavities . the femur and tibia rods may have a treated surface that is adherent to polymethyl methacrylate (“ pmma ”) and other medications that tend to cling to the femur and tibia rods 18 and 19 . as shown in fig4 , the exterior surface of the femur and tibia stems 20 and 21 are formed with irregular surfaces for the purpose of helping to retain the antibiotic coating 29 of fig6 . the irregular surfaces may be in the form of surface grooves 30 and 31 for the femur and tibia rods . this tends to stabilize the antibiotic / pmma coating on the rods . when the surgeon inserts the femur and tibia rods 18 and 19 in the medullary cavities of the femur and tibia , the rods are inserted separately , not when they are joined together in the medullary cavities . once properly installed by moving the femur and tibia rods telescopically into the medullary cavities of the femur and tibia , the femur and tibia may be moved in alignment , causing the femur and tibia rods 18 and 19 to also become aligned , and the surgeon then can align the femur locking pin 24 with the tibia socket 25 , so that the surgeon can grasp the femur and tibia connector collars 22 and 23 with an instrument that urges the connector collars toward one another with the femur locking pin 24 entering the tibia socket 25 with a friction fit . this may also be performed manually . it will be noted that the femur stem 25 is tapered , with the tibia socket having a complementary taper so that when the two are telescopically joined , a friction fit is formed between the femur locking pin 24 and the tibia socket 25 . this is shown in the circled area of fig6 and in the detailed area of fig7 . once the femur rod is joined with the tibia rod 19 as shown in fig6 and 7 , the surgeon has the option to fill the space between the femur and tibia and around the connector collars 22 and 23 with antibiotic coating so that substantially the entire length of the temporary knee implant is coated with antibiotic coating . the pin and socket connection 24 , 25 maintains the femur rod and tibia rods in alignment with one another . this tends to freeze the femur and tibia of the leg of the patient in a fixed , extended position , tending to eliminate the bending of the leg so that a static connection is made . when the sepsis of the knee joint has been eradicated , usually several weeks after the static connection has been made between the femur and tibia of the patient , the surgeon can use an appropriate tool to enter in the space 27 between the connector collars 22 and 23 , and wedge or “ pry ” the femur and tibia connector collars apart . the femur lock pin 24 tends to withdraw axially from the tibia socket 25 . when the surgeon bends the femur with respect to the tibia , the disconnected femur rod and tibia rod are then free to be withdrawn axially from their respective medullary cavities 15 and 16 . the type of antibiotic to be used by the surgeon can be selected to meet the needs of the patient . the antibiotic can be applied to the femur and tibia rods at the site of the surgery , or can be applied by the manufacturer / supplier of the femur and tibia rods , as desired by the surgeon . while the surface of the femur and tibia rods is indicated as being formed by a series of indentations 30 and 31 at the exterior surfaces of the rods , other types of surface treatment may be used , such as but not limited to burling . the procedure includes : first , the infected prosthesis is removed by the surgeon and the knee is thoroughly washed and debrided using standard technique . the femur and tibia are then reamed and further lavaged . the appropriate diameter / length rods are then coated with the pmma / abx mixture or the prefabricated coated rods are brought into the field . once the coating has hardened , the rods are inserted separately into the femur and tibia with the knee flexed , and then the leg is extended until the tibia rod 19 is aligned with the femur rod 20 and the rods are locked centrally in alignment with each other . this will leave a space between the femur and the tibia that may be filled with a conventional pmma / abx spacer that may be created by the surgeon or staff in the or . some of the benefits of the procedure and apparatus are the patient cannot flex the knee , the rods are easily implanted and removed , and the customized antibiotics are directly applied to the infected area . while this disclosure concerns a knee implant and procedure , this invention also may be applied to other joints of the human body . although a preferred embodiment of the invention has been disclosed in detail herein , it will be obvious to those skilled in the art that variations and modifications of the disclosed embodiment may be made without departing from the spirit and scope of the invention as set forth in the following claims .
a temporary knee implant to be placed at the position of the human knee joint for maintaining the tibia and femur at the knee joint aligned during healing of infection in the surrounding tissue . an elongated femur rod is formed with one end of a breadth sized and shaped to extend into the medullary cavity of the femur of a knee , and a connector at the other end , an elongated tibia rod of a breadth sized and shaped to extend into the medullary cavity of the tibia and a connector at the other end , the connectors including interfitting shapes for aligning said femur rod and said tibia rod , and medication adhered to the femur and tibia rods for engagement with the medullary surfaces .