Knee Injury Specialists Helena MT
Family Practice, Sports Medicine
Family Practice, Emergency Medicine
Physical Medicine and Rehabilitation
A Look Back at Long-Term Success For Knee Cartilage Repair
Back in 1995 when surgeons first started using a technique called autologous chondrocyte implantation (ACI), a group of surgeons from around the United States set up a special study to track results of this treatment. They called the collection of data from patients at various clinics and surgical centers the Cartilage Repair Registry or Registry for short. The goal was to follow patients long enough to see how well this treatment worked over time.
Autologous chondrocyte implantation (ACI) refers to the filling in of cracks and holes in the knee joint cartilage with the patient's own chondrocytes (cartilage cells). These lesions or defects occur as a result of trauma, injury, or repetitive damage to the joint. Autologous means that normal, healthy cartilage cells are taken from a place in the patient's own knee joint. The cells come from an area that isn't damaged and doesn't bear a huge load when the person is upright and weight-bearing. The harvested chondrocytes have the advantage of being accepted (not rejected) by the patient's body.
Five years ago, results from the registry were reported. An area of key interest was the durability of the implantation. At that time, results were good-to-excellent for the majority (80 per cent) of patients. There was even evidence that as time went by in the early years, patients continued to improve. Now the researchers present results after 10 years. They used the outcomes after five years and compared it with the results after 10 years to assess durability.
They didn't just look at how well the implant held up. They also evaluated knee alignment, stability of the ligaments, and patellar tracking (knee cap moving up and down over the knee). They collected data on patients' ages, sex (male or female), height and weight, size and location of the defect or lesion, and history of any previous knee surgeries. The data was analyzed in a number of ways trying to see if any one of these factors or variables could be linked with success or failure.
Success was defined as a confirmed defect filling, patient satisfaction with results, and no need for further treatment for the problem. Failure was determined as the need to remove the graft for any reason, the need for partial or complete joint replacement, and failure of the defect to fill in (seen on imaging studies). Most of the failures (17 per cent) occurred early on (in the first two and a half years)
Looking at patient characteristics, it turns out that most of the patients had normal knee (including knee cap) alignment before surgery. Three-fourths of the patients who ended up with autologous chondrocyte implantation (ACI) had at least one previous knee surgery (e.g., arthroscopy, debridement, meniscal repair or removal). One-fifth of the group didn't just have an ACI procedure but also had some other procedure to improve knee alignment or repair a torn or ruptured ligament.
As far as the cartilage lesion goes, two-thirds of the p...
A Review of the Research on Knee Replacement Surgery
The number of surgeries to replace part or all of the knee joint has tripled in the last 10 years. Along with that increase has come many changes in the way reconstructive knee surgeries are done. In this specialty update, all aspects of knee surgery are researched and reviewed.
What can you expect to find in this article? First, an analysis of trends and costs associated with knee surgery. Then the authors present an update on surgical techniques and complications. These two sections are followed by a summary of outcomes (results) for each type of implant and in specific patient groups. Let's look at each one of these and see what's new.
Along with an increase in volume (number) of reconstructive knee surgeries has come a push to reduce costs. By studying data from hospitals, it looks like the time it takes to do a knee replacement has dropped by 20 minutes in the last 15 years. They say that "time is money" and that applies to hospitalizations. Longer operations cost more and increase the risk of complications.
There's been a trend away from hospital-based surgeries as more surgeons specialize in a particular procedure such as reconstructive knee surgery. That has led to high-volume specialty centers where surgeons perform many knee joint replacements each week. The result has been improved outcomes, fewer complications, and lower costs.
With improved technology, surgeons have been able to offer patients improved standard of care. For example, computer navigation and tools to make more specific cuts have reduced differences that occur from surgeon to surgeon. More careful attention to the mechanical axis of the implant has also improved how long the implants last. A natural outcome of that focus has been improved function for patients.
Another change in how surgeries are done has been the move from open incision to minimally invasive surgery. Many, many studies have been done comparing the two methods. Is one better than the other? With less cutting are there fewer complications? Does the surgery take less time with minimally invasive procedures and thereby save money?
Along with smaller incisions that preserve the soft tissues has come a concept called rapid recovery rehab. Patients are up and walking and putting weight on the knee right away. Everything in the rehab protocol is speeded up. Although the improved short-term results with a faster rehab cycle have been shown, there are still too many mixed or opposite results reported when comparing minimally invasive to open incision surgeries to say for sure that one is superior to the other.
Two other areas that were reviewed included patient outcomes and complications with each of the major types of joint implants. Let's start with types of implants. There's the standard (cruciate ligament retaining) knee design, high-flexion, mobile-bearing, fixed-bearing, and patellar replacement versus resurfacing. Each of these was developed with specific problems or patient fa...
Preventing Kneecap Dislocations
The patella (more commonly known as the "kneecap") moves up and down in front of the knee joint along a built-in track called the patellofemoral groove. It is held in place by several ligaments on either side and by the patellar tendon (attached to the quadriceps muscle). The quadriceps muscle is the large, four-part muscle along the front of the thigh.
Although you can take your hands and passively move the kneecap from side to side, this is not an active movement you can make your patella do without assistance. We call that side-to-side (medial-to-lateral) movement accessory motion. The up-and-down and side-to-side accessory motions are referred to as patellar glide.
As part of the patellar tendon, there are slips of ligamentous fibers that help hold the patella in place and keep it from moving too far to one side or the other. On the inside of the kneecap is the medial patellofemoral ligament. On the outside is the lateral patellofemoral ligament.
Without the medial patellofemoral ligament, the kneecap dislocates laterally (in a direction sideways away from the other knee). Because the medial patellofemoral ligament is connected with other ligamentous structures, complete rupture will likely damage other areas as well. The medial patellofemoral ligament attaches above to the femur (thigh bone) and below to the tibia (lower leg bone).
Most ruptures occur at the femoral attachment. But the ligament can tear away from the tibial attachment or even in the middle (not at either bone attachment). This type of tear is called an intrasubstance tear.
A medial patellofemoral ligament injury can be treated conservatively without surgery. The knee may have to be immobilized in a splint for a number of weeks to allow for healing. Physical therapy, taping, and a home program of exercises prescribed by the therapist begin after the period of immobilization. The rehab program must be given the good old college try: in other words, for more than a few days or weeks. It can take months to rehab this injury.
But if nonoperative care fails and the patella dislocates again, then surgery to repair or reconstruct the ligament may be the next step. The surgical approach that works best depends on the underlying damage and specific patient factors.
The surgeon will use an arthroscope to look inside the joint and assess the damage before performing the actual repair. In this study, there was an equal number of patients with medial patellofemoral tears at the femoral, tibial, and intrasubstance locations.
Results were viewed in terms of final outcome (patellar stability or instability with another dislocation) but also included clinical data. Range of motion for the hip and knee was measured.
X-rays were taken to look at the position and angle of the patella over the femur. Knee function and disability were also measured.
Nearly three-fourths (72 per cent) of the patients had a stable patella with no episodes of redislo...