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Choosing the Correct Surgery for Posttraumatic Knee Arthritis
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Posted on: 02/25/2009
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Patients who injure their knees often need surgery to repair the damage or reconstruct the knee. There could be a fracture or torn ligament(s) that requires immediate surgical attention. In many cases, arthritis develops in that knee and creates another problem later. In this article, two orthopedic surgeons provide a thorough review of what to do when posttraumatic knee arthritis gets worse and requires surgical treatment.
The surgeon has some basic decisions to make about what surgery to do beginning with type of patient. For example, younger patients who are still active can be treated with an osteotomy or arthrodesis (fusion). Older, less active adults with posttraumatic knee arthritis may fare better with an arthroplasty (joint replacement).
Osteotomy refers to the removal of a wedge-shaped piece of bone from one side of the knee. The remaining bone is moved to fill in the area where the wedge was removed. This procedure helps realign the bones and joint and redistribute weight and load.
Each of these procedures for the surgical management of posttraumatic knee arthritis is discussed in detail. The authors present common challenges surgeons face leftover from the surgery for the original injury. X-rays, intraoperative photographs, and drawings are included to show types of cases encountered and surgical management for difficult problems.
Some of the issues surgeons must deal with include broken hardware, scar tissue, stiffness, bony defects, malalignment of the joint, and other bone or joint deformities. Each of these problems must be taken into consideration when planning the treatment approach. The surgeon continues the decision-making process with a careful evaluation of the patient.
Location and quality of pain are noted. Range of motion is measured. The patient's gait (walking pattern) is examined and analyzed. Tests for knee instability are performed. X-rays are taken to look for limb malalignment, fractures, and status of the hardware. And finally, lab tests are ordered if there is any suspicion of joint infection.
The surgeon takes into consideration the patient's age, expectations, and goals, along with current activity level and desired activity level. The condition of the knee joint is also a deciding factor in what surgical option is best.
Osteotomy is a corrective procedure. It is used most often in younger adults to unload one side of the joint that is bearing the brunt of the burden. Arthritis affecting just one side of the knee joint is called unilateral or single-compartment degenerative disease. By unloading the side affected by arthritis the most, the knee can be spared much longer. Osteotomy buys the patient time before a total joint is needed.
Patients who benefit from osteotomies usually had a fracture around the knee that resulted in a leg length difference. Malunion or deformity after fracture or ligamentous healing can be treated with an osteotomy. The technique allows the surgeon to restore a more normal mechanical axis (center) of movement while spreading out the forces across the entire joint surface.
Different types of osteotomies can be done from either side of the joint. Determining the best surgical approach for osteotomy requires additional evaluation procedures and preoperative planning. The authors guide surgeons through the steps in making this decision.
There's an alternate surgical procedure that can be done when osteotomy isn't enough or isn't possible in the young patient. That's an allograft transplantation. Bone from a donor or bone bank is used to replace bone lost. The transplanted bone dies but the body generates new blood to the area and forms its own bone to replace the allograft. Over a period of months to years, the body fills in with its own bone.
When none of these salvage procedures can be done, the surgeon may have to fuse the joint. This is called an arthrodesis. A fusion allows the patient to bear weight and walk on the involved leg. Of course, there are some problems with walking stiff legged. It's hard to get dressed when you can't bend your knee. And eventually, the hip and back start to hurt because of the altered biomechanics and movement.
Some patients just aren't good candidates for a fusion or they don't want to deal with the hassle of a leg frozen in one position. In those cases, joint replacement may be the best (or only) option left. Older adults with a painful knee and limited motion from progressive degenerative changes may skip right to a total knee replacement (TKR).
Here again, the surgeon is back to facing some of the difficult challenges mentioned before. There may be lots of hardware (plates, screws, pins) in and around the joint from the previous surgery to hold the broken bones together. All of this hardware must be removed without damaging the bone. The surgeon may remove only what's absolutely necessary and leave the rest in place. These decisions are made on a case-by-case basis.
Along with dealing with hardware is the issue of scarring and incisions. Whenever possible, the surgeon tries to go back into the joint using the previous incision. But there are lots of things to consider in the process. Will disrupting the delicate skin cause more problems? Is there enough blood circulation to the area to make healing possible? Is there enough skin to sew back together after the procedure is finished? The surgeon may consult with a plastic surgeon if the preoperative tissue condition is a concern.
The next challenge to consider is the stiff knee. The surgeon can't just cut the tendons and joint capsule, go in, and replace the joint. Too much force could cause the brittle soft tissues around the knee to tear or pull away from the bone completely. Sometimes the quadriceps muscle along the front of the thigh is severely contracted. The surgeon must cut through the quadriceps tendon very carefully. The authors present the surgeon with different ways to do this safely, avoiding tiny, but important, blood vessels in the area.
Malunion or nonunion of the original damaging fracture(s) can alter the joint mechanical axis making it impossible to replace the joint. The implant wouldn't be straight or balanced and uneven wear or loosening could occur. In such cases, it may be possible to perform an osteotomy first to realign the joint before putting in the joint replacement.
But once again, another complicating problem may be present and that's bone loss. Without enough bone to set the implant into, the surgeon may have to use bone grafts, cement fill, or special screws to manage the problem.
The surgeon may finally get to the place where it's possible to perform a total knee replacement but the decision-making process isn't over yet. Now it's time to choose the right prosthesis (implant).
Because the knee was injured before, even with stabilization and reconstruction, there are usually soft tissue imbalances still remaining. Any ligament imbalances will dictate which implant can be used. The surgeon must assess which ligaments are impaired and choose the implant that will stabilize the knee, support the weight-bearing surface, and minimize stress on the impaired ligament.
When it's all said and done, the long-term outlook for total knee replacement for traumatic arthritis is fair-to-good. Patients experience a reduction in pain, increased motion, and improved function. The results aren't always perfect. The postoperative range-of-motion depends on how much motion was there before surgery.
Sometimes the patella (knee cap) doesn't move up and down like it should. This motion is called patellar tracking and is important for normal knee function. If scar tissue or muscle contracture is preventing normal patellar tracking, then additional surgery may be needed to correct the problem.
Tendon rupture, failure of the wound to heal, and even implant failure are common problems that may be encountered. Patients should be counseled ahead of time what can happen and what to expect. The surgeon can expect and should watch for a high rate of complications after total knee replacement for these posttraumatic arthritis patients.
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References:
Asheesh Bedi, MD, and George J. Haidukewych, MD. Management of the Posttraumatic Arthritic Knee. In Journal of the American Academy of Orthopaedic Surgeons. February 2009. Vol. 17. No. 2. Pp. 88-101.
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*Disclaimer:*The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic. |
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