Dow Corning Wright Corp. v. Osteonics Corp.

939 F. Supp. 65, 1996 U.S. Dist. LEXIS 13538, 1996 WL 528415
CourtDistrict Court, D. Massachusetts
DecidedAugust 16, 1996
DocketCivil Action 91-10962-GAO
StatusPublished
Cited by1 cases

This text of 939 F. Supp. 65 (Dow Corning Wright Corp. v. Osteonics Corp.) is published on Counsel Stack Legal Research, covering District Court, D. Massachusetts primary law. Counsel Stack provides free access to over 12 million legal documents including statutes, case law, regulations, and constitutions.

Bluebook
Dow Corning Wright Corp. v. Osteonics Corp., 939 F. Supp. 65, 1996 U.S. Dist. LEXIS 13538, 1996 WL 528415 (D. Mass. 1996).

Opinion

MEMORANDUM AND ORDER

O’TOOLE, District Judge.

The plaintiff Dow Corning Wright Corporation (“DCW’) brought suit against Osteonics Corporation alleging that Osteonics infringed a patent held by DCW relating to a method and apparatus to prepare a human femur to receive an artificial knee. After a trial in which a jury found for Osteonics, DCW appealed to the Federal Circuit. DCW argued that the issue of claim interpretation, which the Court had submitted to the jury, should have been decided by the trial judge. The Federal Circuit agreed, vacated the decision, and remanded for a new trial. Osteonics now moves for summary judgment on the basis that a proper interpretation of the claim by the Court would require a verdict in its favor. The Court agrees and grants Osteonics’ motion.

I. FACTUAL BACKGROUND

By assignment from inventor Dr. Leo Whiteside, DCW owns U.S. Patent No. 4,474,177, describing a set of instruments and a methodology used in knee-replacement surgery (the ‘Whiteside patent”). Knee-replacement surgery typically involves attaching an artificial knee directly to the end of the femur (the thigh bone). As explained in both parties’ briefs, a surgeon must be very precise in performing this procedure, not only so that the knee fits well but also so that the new knee is properly aligned with the leg bones. If the correct alignment is not achieved, the patient may develop an improper gait or other complications.

The process by which the alignment is achieved involves cutting and preparing the distal femoral surface (the lower surface of the femur) so that it can receive the knee implant. The proper preparation of this surface is the key to realizing the desired alignment.

A primary difficulty in aligning an artificial knee arises because the femur does not typically extend vertically from the hip downward but is instead at an angle offset a few degrees from vertical. The angle between the imaginary line running through the central shaft of the femur, called the central long axis of the femur, and the vertical axis is known as the varus/valgus axis. The portion of the knee implant attached to the femur needs to duplicate this angle in order to sit properly. Approximating the varus/valgus angle is naturally simplified if one can identify the central long axis of the femur.

None of the above is claimed under the Whiteside patent; as stated in the background section of the patent itself, “It is a common practice to use the long central axis of the femur as a guide in determining the maimer in which the distal femoral surfaces should be shaped to receive a properly *67 aligned distal femoral prosthesis.” Column 1, lines 22-25. Rather, the Whiteside patent provides a way of identifying the central long axis by relying on the femur’s internal geometry. The human femur is not solid but has an internal cavity, known as the intramedullary canal, that extends the length of the shaft of the femur. In most persons, the central long axis runs approximately through the middle of this canal.

The Whiteside patent employs a rod that the surgeon can insert into the canal at the knee and press upwards toward the hip. The rod, which in its preferred embodiment is 10 inches long (the average human femur is about 15 inches), passes through the intramedullary canal to its narrowest portion, called the canal’s isthmus. The rod is consequently called an “intramedullary rod.” The object is that, once fully inserted, the center of the intramedullary rod and the central long axis of the femur are collinear. To secure the rod in place, the physician impacts the rod with a mallet that drives locking fins on the rod into the bone. The rod has an angled handle on its end that projects from the end of the femur when the rod is inserted in the canal. The angle corrects for the patient’s varus/valgus angle. Each White-side system comes with a set of rods with handles angled at 3, 5, 7 and 9 degrees to account for the varus/valgus angles of different patients.

Once the rod is in place, different femoral surface shaping instruments can be placed on the handle to make the proper cuts in the distal femoral surface. The Whiteside patent system employs three such guides — an anterior-posterior cutting guide, a distal femoral condyle cutting guide, and a bevel cutting guide — to make the cuts, as well as a plateau planar to flatten the distal femoral surface.

The Whiteside patent’s procedure also employs a reamer prior to the use of the rod. Before anything can be inserted into the intramedullary canal, a hole must be drilled into the femur to allow access to it. After drilling, the reamer is inserted into the hole and pressed through the canal. The reamer is used to correct any error as to the location of the entry hole and to file away deformities in the canal that might throw off the alignment of the rod. As described in claim 1 of the patent, the reamer is comprised of “a rod having a portion which is intended to enter the intramedullary canal and ... has a plurality of cutting ridges situated about its circumference, the remaining portion of said rod having a means for imparting a twisting motion to said reamer____” Column 11, lines 48-55. The Whiteside patent was issued on October 2,1984.

Prior to 1989, Osteonics, a manufacturer of medical instruments, was selling a surgical knee instrument, called the OMNIFIT system, but was not satisfied with its system. In the summer of 1989, Osteonics enlisted the aid of two orthopedic surgeons, Dr. Phillip Merritt and Dr. Bradford Hack, to develop an improved set of instruments. These surgeons, who were both familiar with the Whiteside instruments and method and who had observed Dr. Whiteside use them in surgery, designed their own knee-replacement instrument system.

According to Dr. Merritt, his goal was to design a system that also relied on the internal geometry of the femur but that avoided some of the problems of the Whiteside system, especially for average orthopedic surgeons who were not necessarily expert in knee replacement surgery. Mentlik Declaration, Ex. C at 501, 576-77. First, they wanted to use thinner and shorter rods. They thought that the larger and thicker ones risked fracturing the femur or shaft of older patients who had more fragile bones. Second, they thought that the Whiteside system, by fixing the rotational alignment of the cutting blocks on the guide handle, required to much “eyeballing”; the surgeon using the Whiteside system visually determines the rotational alignment by sighting equal amounts of the posterior portions of the femoral condyles behind the lower edge of one of the cutting guides. See Whiteside patent at column 9.

The system Drs. Merritt and Hack designed for Osteonics, called the “STAT-IM” rod system, consequently also uses a series of intramedullaiy rods with angled handles. The Osteonics rods are slightly shorter (about 8.3 inches in length) and slightly thinner (0.33 inches in diameter as opposed to *68 O. 38 inches) than the preferred embodiment of the Whiteside rods. 1 The Osteonics system does not employ a reamer. Rather, after a hole is drilled, the rod is simply inserted. The system does, however, employ a mallet and locking fins on the rod to secure the rod in the canal, and available Osteonics rods are angled like the Whiteside rods.

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Bluebook (online)
939 F. Supp. 65, 1996 U.S. Dist. LEXIS 13538, 1996 WL 528415, Counsel Stack Legal Research, https://law.counselstack.com/opinion/dow-corning-wright-corp-v-osteonics-corp-mad-1996.