Severe arthrosis of the knee can be generalized to the entire joint or confined to only a small part, a so-called compartment of the knee: in this specific case, this arthrotic condition can be treated with a smaller-than-total prosthesis, called a unicompartmental prosthesis.
The single-compartment knee replacement, in fact, is a minimally invasive surgical procedure and alternative to total knee replacement, particularly suitable for those patients whose problem is limited to only one area of the knee: medial, lateral, or patellofemoral. Because this surgery is performed through a small incision, the hospital stay is shorter and patients are able to return to their normal activities within a short time.
The advantages of a unicompartmental prosthesis are:
- The very short recovery time.
- Remarkable containment of postoperative pain and bleeding.
- A better subjective feeling of “having your own knee” than a total knee replacement.
Obviously, the unicompartmental knee replacement represents only one of the viable options forosteoarthritis, and the surgeon will be the one to evaluate the most suitable one based on the specific case.
When is it needed?
As we have already mentioned, when osteoarthritis affects only part of the knee, total joint replacement can be avoided, keeping some structures intact and thus optimizing the success rate of the surgery.
The main indications for unicompartmental knee replacement are:
– Arthrosis of the medial compartment of the knee, with preservation of the cartilage of the outer compartment and integrity of the cruciate and collateral ligaments of the knee;
– Arthrosis of the lateral compartment of the knee, with preservation of the cartilage of the inner compartment and integrity of the cruciate and collateral ligaments of the knee;
– osteonecrosis of the medial or lateral femoral condyle and integrity of the remaining osteoarticular structures of the knee.
The operation of unicompartmental prosthesis
In unicompartmental prosthesis surgery, replacement of only the damaged knee component is performed so as to eliminate pain. It is a much less invasive surgery than total knee replacement and lasts from half an hour to an hour.
After making an incision in the anterior part of the knee, the cartilage of the damaged part will be removed and metal prosthetic liners will be placed (and fixed with a special cement) to recreate the normal joint surface. Finally, a very high-density polyethylene shim will be inserted between the two metal parts to facilitate friction and recreate the original cartilage volume.
For this type of surgery, in order to place the components with pinpoint accuracy, the use of artificial intelligence (robotic surgery) can also be used. These are robotic arms that help the surgeon cut with great accuracy the minimum thickness of bone and cartilage to implant the prosthesis components.
The revision surgery
Compared with a few years ago, the number of patients undergoing unicompartmental knee replacement surgery has greatly increased, mainly due to improved surgical techniques and the use of better performing materials.
A particularly informed person may have read on the Internet that in cases of unicompartmental knee replacement, the probability of revision compared with total knee replacement is higher 10 years after surgery. In reality, the revision rate is very low if this surgery is performed in specialized centers with surgeons who perform 12 to 30 unicompartmental knee replacement surgeries per year.
The advantages of the monocompartmental prosthesis
Most patients who are ideal candidates for this type of procedure have excellent results with single-compartment knee replacement. The advantages of partial knee replacement, include:
- Faster functional recovery;
- Reduced postoperative pain;
- Less intraoperative blood loss.
Contraindications
Patients thinking of undergoing the procedure, however, should be informed that there are contraindications regarding the implantation of a monocompartmental prosthesis. These arise in the case of:
- Absence of an anterior cruciate ligament or posterior cruciate ligament capable of providing stability to the knee;
- Severe laxity of the collateral ligaments of the knee;
- Arthrosis of multiple components of the joint;
- Rheumatologic diseases affecting the joint.
👨⚕️ How to decide together with the surgeon
The choice between performing total knee replacement or single-compartment knee replacement surgery is not simple: it must be tailored to the patient’s age, needs, activity, and response to conservative treatments.
Thorough clinical evaluation and transparent dialogue with the specialist enable the best decision to be made at the right time.
📞 Call to Action
Do you have knee pain and wonder if it’s time for surgery?
Book a specialist consultation with Dr. Federico Giardina.
📍 Bologna | 📞 3519390882
Email: federico.giardina@ior.it
👉 Book now
