Partial Knee Replacement or Knee Resurfacing

One of the newest treatment technologies offered in orthopedics today is partial knee replacement. It’s also known as Uni-Compartmental Knee Replacement, knee resurfacing, Partial Knee Arthroplasty or PKA.

Partial knee replacement is a true alternative to traditional total knee replacement. Knee resurfacing is performed by replacing only the worn-out, arthritic compartments of the knee versus the more traditional knee replacement approach, where the entire knee is replaced. This approach is especially appealing for the younger, more active patient who does not have any cartilage remaining on a portion of their knee. Post-operatively, this approach also offers the potential for the patient to return to a fairly high level of physical activity. During PKA, only the portion of the knee which is damaged – usually by arthritis – is replaced, leaving the rest of the knee intact and in its natural state. Arthritis has a tendency to produce bone spurs and jagged edges, so during PKA, the surgeon will remove any spurs and trim the ends of the bones.

Partial Knee Replacement Implant Technology

New advances in Computed Tomography (CT) technology now make it possible for implant manufacturers to utilize a simple CT scan of the knee to construct an exact, three-dimensional model of a patient’s knee. After the anatomically-correct model is created, the manufacturer can then fabricate the necessary implants required to replace the arthritic areas of the knee.

Although most computer-generated knee replacements involve having a pre-operative MRI scan or CT scan of the knee, resurfacing is different from other computer-designed knee replacements that are currently being advertised. Most manufacturers of knee replacement implants make a left knee and a right knee model in a variety of different sizes. A patient’s knee will be cut down to accommodate whichever size of implant most closely approximates their natural knee. Surgeons use cutting guides or “blocks” which are made to facilitate the implantation of the pre-fabricated knee implant, no matter if the replacement is to be a traditional or computer-designed procedure. In a knee resurfacing procedure, there are no pre-manufactured cutting blocks or implants. The patient’s own knee is utilized to make the model on which the patient’s custom-made implants are then manufactured. Disposable guides and cutting blocks are sent to the surgeon to ensure anatomic positioning of the implants.

Some advantages to Partial Knee Replacement are:

• A smaller incision is used, resulting in less tissue damage, reduced bleeding and less scarring.
• The muscles, tendons and ligaments surrounding the knee are not detached or cut, resulting in less pain associated with trauma to the musculature of the knee, as is usually seen with Total Knee Replacement surgery.
• The patient is left with much more knee bone than after a traditional Total Knee Replacement. All Total Knee replacements require that a patient’s knee be “prepared” to receive the implant, which usually requires significant bone removal and shaping before the implant can be positioned into place. In a partial knee replacement, the implant is the thickness of the damaged cartilage that is being replaced. The surgeon does not have to remove as much bone to achieve the proper fit and positioning of the implant. This is an important benefit should the patient ever require a revision surgery or if they have to have a Total Knee Replacement at some point in the future, due to the progression of their knee arthritis.
• More surgical options are available if the knee needs to be fully replaced at a later date. Since a minimal amount of bone is removed during the knee resurfacing procedure, it is much easier to convert a resurfaced knee to a traditional primary total knee replacement, should the need arise due to complications from arthritis or injury later. While not for everyone, knee resurfacing is a great alternative to total knee replacement for younger, active individuals who want to maintain an active lifestyle.

Recovery from Partial Knee Replacement, which is outpatient, is much quicker than from Total Knee Replacement, with:

• Less pain during recovery
• Less time in Rehabilitation and Physical Therapy
• Greater range of motion more quickly
• A more natural-feeling knee

There are some criteria that should be met before you can be considered for Partial Knee Replacement, such as:

• Your knee arthritis must be limited to one or two compartments of the knee, such as the kneecap and either the inside or the outside of the knee. If your knee arthritis affects your entire knee, PKA is not for you.
• You must also have intact ligaments surrounding your knee, such as the Anterior Cruciate Ligament (ACL).
• Patients who qualify for this procedure should not be obese.

To make an appointment for a consultation for Partial Knee Replacement, call our Appointment Desk at 757-596-1900. Our Orthopaedic Specialists can help you decide if PKA is the right choice for you.