When one side of a person's knee joint is worn due to arthritis, either from injury or a deformity, the typical answer is a partial knee replacement, in which only the most damaged areas of cartilage are replaced instead of the entire joint.

However, even with this more minimally invasive option, the incision for a partial knee replacement can be as long as 4 inches, resulting in significant pain and recovery time for the patient, says Dr. Ron Clark, a South Bend orthopedic surgeon.

Still, Clark says there hasn't been much urgency in the surgical world to change what is regarded as a highly successful surgery. From a surgeon's point of view, the procedure is effective and let's face it, it doesn't hurt the doctor a bit.

In 2002, when Clark first learned to put in partial knee implants, he thought there had to be a better way to do the partial implant through a smaller incision and by disturbing less tissue, resulting in a faster and less taxing recovery for the patient. He wanted the device to be implanted more readily with the use of the artheroscope, a ballpoint pen-sized surgical tool fitted with a tiny camera.

"I came up with a concept that I thought would address some of the problems that the previous design had," he said. "It was mainly related to the way in which the lower bone was surgically approached."

So he contacted Ross Mack, a retired engineering professor from Valparaiso University who helped him begin the process of designing a new device that addressed some of the previous shortcomings.

Together with Mack, and a patent attorney, Mark Morrison, Clark formed a company, Valparaiso Orthopedic Technology, and organized a team to develop and distribute the Solo Partial Knee System. In 2005, the three founders incorporated and moved the company out of Clark's home. Now known as VOT Arthroscopic Solutions, the orthopedic medical device company is now located in Warsaw, Ind.

In March of 2008, the final version of the VOT device was FDA-approved. In December of 2008, the first patient received Clark's partial knee implant. To date, Clark has used the new implant in about 24 patients, who he says are reporting high levels of satisfaction.

As word of the device spreads among physicians and more doctors undergo training to use it, the numbers of successful operations are rising, Clark says, with three other doctors currently trained to date.

Though using the device is a little more challenging for the surgeon, it is certainly preferable for the patient, who can walk away with a 1-1/2-inch incision instead of up to 4 inches. Though there have been no formal studies by VOT to back the claim, the result - at least in Clark's practice - is an acceleration in recovery by about 50 percent as compared to the traditional partial knee replacement. Clark has found his patients typically go home the same day and require about half the recovery time. It will take several years to truly see how well the implant functions and whether the early good results hold up.

The ideal candidate for a partial knee replacement with the Solo implant is a patient with deterioration on one side of the knee. Clark says the technology is especially exciting news for younger patients, those 60 and younger, who can get relief while staving off a total knee replacement which is likely to be needed later. He says the less traumatic surgery is also good news for the older patient who has a less demanding lifestyle and might not ever require additional surgery.

Most importantly, Clark says the improved procedure means less patients will have to endure a painful waiting game.

"Many times, patients postpone major knee surgery because they are told they are too young and that they have to wait," Clark says. "That's because when you operate on a knee you remove bone that can never be replaced. This system removes very little bone so should it not last the entire life of the patient, it has the advantage of being interchangeable to other types of knee devices so that patients have more options."

For information about the Solo Partial Knee System, call VOT Arthroscopic Solutions at (866) 942-9498.