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Dr. Michael Repine: Treating Knee Arthritis

By the time we’re 50, our knees have carried us more than 75,000 miles. Most of us don’t give our knees a second thought – until degenerative knee arthritis takes its painful toll and limits our day-to-day activities.

Knee osteoarthritis occurs when the knee joint’s cartilage – a smooth, slippery substance that lines the ends of bones – wears away.

“Healthy, normal cartilage allows the ends of bones to roll and slide easily against each other during motion,” explains Boulder Medical Center orthopedic surgeon, Dr. Michael Repine. “Unfortunately, too much wear on the cartilage surface leads to its deterioration, similar to how the tread on tires of a car wear down over time.

Speaking at a recent Boulder Community Health lecture series, Dr. Repine explained: “osteoarthritis of the knee is the mechanical wearing down of the cartilage surface. When the cartilage is thinned or absent, problems such as pain, swelling, instability and limited motion occur.”

Fortunately, there are many approaches for relieving the pain of knee arthritis, from non-surgical treatments to new surgical options.

Knee Arthritis Symptoms

The symptoms of knee arthritis can include:


  • During weight-bearing activities
  • While sleeping at night
  • Located across entire knee or focally to an area
  • Usually slow in onset, with a gradual increase


  • Warmth in the joint
  • Swelling or stiffness, which can be more pronounced after a period of inactivity
  • Limited motion
  • Loss of flexibility or restricted range of motion in the joint
  • Overall weakness, causing the knee to give way or buckle
  • Grinding, creaking, cracking or popping sounds during movement

Non-Surgical Treatments for Knee Arthritis

According to Dr. Repine, physical therapy is almost always the first step in treatment for knee arthritis, with the goal of reducing pain and improving range of motion and strength. He describes non-surgical treatments and the pros and cons of each:

Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)

  • Pros: Decreases inflammation and pain
  • Cons: When used long term, there is a risk of gastrointestinal bleeding

Nutritional Supplements

  • Pros: Many sufferers find nutritional supplements, such as glucosamine and chondroitin, helpful
  • Cons: Too many of these products don’t measure up to their claims and data on proven effectiveness. None have passed FDA testing as proven effective
  • Dr. Repine recommends:  Since there are thousands of supplements on the market, conduct your own personal trial study. Take a supplement for a while to see if it works for you

Cortisone Injection

  • Pros: Relatively well-tolerated, easy procedure done under fluoroscopy that offers very predictable reduction in pain. It often “buys time” for patients whose joint isn’t quite ready for total replacement
  • Cons: The injection must be placed carefully and can soften the cartilage. Also, it tends to mask symptoms

Viscosupplement Injection (hyaluronic acid)

  • Pros: Protects remaining cartilage and helps improve the biochemical environment of the joint, offering reliable reduction in pain
  • Cons: None, with appropriate patient selection. However, there’s a small potential for reaction with repetitive administration

Stem Cell Therapy

  • Pros: Anecdotal reports appear promising when osteoarthritis is caught early
  • Cons: It’s expensive and uses are still being heavily researched

State-of-the-Art Surgical Treatment:
Mako Robotic-Arm Assisted Surgery

Many people with knee osteoarthritis look to surgery as a way to get relief from bone-on-bone pain and resume the physical activities they love. Arthritis located in a well-defined area is most often treated arthroscopically. Sometimes cartilage transplantation or resurfacing can also be an option.

“For these surgical treatments to be effective, we must catch the damage early on, before any secondary bone changes occur,” says Dr. Repine. “You can ‘miss the boat’ for certain procedures.”

Advanced arthritis often requires more advanced surgical options, including Mako Robotic-Arm Assisted Surgery for partial knee resurfacing and total knee replacement. In this procedure, computer-assisted Mako technology uses a state-of-the-art robotic arm with computer-guided mapping software, allowing for the highly accurate placement and alignment of a knee implant.

“When you hear ‘robotic-arm assisted technology,’ it’s important to understand that the Mako Robotic-Arm doesn’t actually perform the surgery,” explains Dr. Repine. “Surgery is performed by an orthopedic surgeon, who uses the Mako System software to pre-plan your surgery. Your surgeon will guide the Mako robotic-arm to remove diseased bone and cartilage and insert an implant.”

Mako Technology was designed to help surgeons provide patients with a personalized surgical experience based on their specific diagnosis and anatomy.

“Mako Total Knee Replacement is a real game changer,” Dr. Repine says, “The robotic incisions are so much smaller than conventional surgery procedures. It also can offer the potential for a shorter recovery time and a more natural feeling knee for knee replacement patients.”

If you suffer from symptoms of knee osteoarthritis, schedule an appointment with Dr. Michael Repine in the Boulder Medical Center orthopedic department.

About Michael Repine, M.D.Michael Repine

Although he was born in Minnesota, Dr. Repine considers himself a Colorado native after living here for over 25 years and completing his higher education at the University of Colorado. After earning an Bachelor of Science degree in biochemistry from the CU Boulder and Doctor of Medicine from the CU School of Medicine, he went on to serve his orthopedic residency and internship at the CU Health Sciences Center.

Dr. Repine is trained to provide the spectrum of orthopedic care, from minimally invasive options to advanced robotic surgery. He is one a select group of orthopedic surgeons certified to perform the innovative MAKOplasty® procedure for partial knee surfacing and total hip and knee replacements.

As an avid outdoor enthusiast, Dr. Repine’s favorite activities include mountain biking, windsurfing and snowboarding. He considers a good sense of humor to be an essential part of his character.