Osteotomy & Chondral Resurfacing: Biologic Knee Preservation

 WhWhatSome patients with osteoarthritis in one part of the knee can avoid knee replacement surgery for many years, and sometimes for ever by having an osteotomy (HTO), combined with a chondral resurfacing procedure. This type of procedure is often called "Biologic Knee Replacement:, as it allows the patient to have a high functioning knee without the downsides of a artificial knee replacement. Typically the osteoarthritis or cartilage (chondral) injury is in the medial compartment and the patient has a bowed leg, known as varus. By straigtening the leg, the pain & function is much improved. Also the HTO usually allows the cartilage joint surface to improve. Often osteotomy is combined with a chondral repair/ restoration such as, marrow stimulation or mosaicplasty if the joint surface lesion is Grade IV.  Cartilage repair procedures cannot be done in isolation unless limb mal-alignment is corrected.


HTO Combined with  ACL Reconstruction

It is quite common for patients with medial osteoarthritis to also have a chronic ACL tear. Usually the ACL tear was the primary event, with a medial meniscal tear the secondary event and medial osteoarthritis as the final end result.  ACL & HTO is a very successful procedure, relieving pain & restoration function. 

HTO Procedure

The preoperative x-ray shows the medial compartment is narrowed as a result of osteoarthritis. The limb is too “bowed” or as surgeons call it, in “varus”.

Initial guide wire is placed across the tibia

Distractor is placed across the tibia

Distractor is gently opened

Trial Wedge is inserted

Plate is applied and held while screws are inserted

Final HTO plate appearance with Bone Graft to gap

 

Aftercare

Patients are usually in hospital for 1-2 nights, and  have restricted weight bearing for 2-4 weeks after the surgery ie, on crutches. Depending on progress, they can start riding a bike within a two weeks.  Full recovery is up to 6-9 months.  Most patients a marked improvement in their pain for 10-12 years. It does not effect the later outcome of a knee replacement if performed with modern techniques.  

 

Complications

Risks are mainly in the post-operative phase, and include infection 1:100, Non-union 1:50, Hardware Removal 1:10, Numbness around the wound 1:20 and Slight Loss of knee range of motion 1:10.

In patient under 55 years of age who are not overweight, an osteotomy can be a much better alternatives than either partial or total knee replacement

There is some evidence that this allows to articular surfaces to recover and slows the rate of osteoarthritis. 

The Australian Hip &  Knee Registry has identified a higher revision rate in males under 55 with partial knee replacement, compared to older patients.

To relieve the pain, the limb mal - alignment is corrected back to neutral or slightly over-corrected, through a small 2 inch incision over the medial tibia. 

The left image is an x-ray taken while Dr Vertullo is performing an osteotomy, putting the final plate into place. The plate contains a small wedge, that hold the bony correction open while it heals, and the screws hold the plate in place.  If the correction is large, artificial bone graft helps the bone heal faster. The average correction required is 10 degrees.  

Patients are usually in hospital for 2 nights, and touch weight bear for 6 weeks after the surgery on crutches. Depending on progress, they can start riding a bike within a four weeks.  Full recovery is up to 6-9 months.  Most patients a marked improvement in their pain for 10-12 years. It does not effect the later outcome of a knee replacement if performed with modern techniques.  

Risks are mainly in the post-operative phase, and include infection 1:100, Non-union 1:50, Hardware Removal 1:10, Numbness around the wound 1:20 and Slight Loss of knee range of motion 1:10.