Knee Osteotomy
What Is Knee Osteotomy?
Knee osteotomy is a joint-preserving operation in which a controlled cut is made in the shin bone (tibia) or the thigh bone (femur) so that the alignment of the leg can be corrected. The joint surface itself is not replaced. What changes is the path body weight takes through the knee: load is shifted away from the worn compartment and onto the side where the cartilage is better preserved. The aim is to reduce pain, slow further wear and postpone the point at which joint replacement becomes necessary. Because the knee keeps its own cartilage, menisci and ligaments, osteotomy differs fundamentally from replacement surgery.
When Is Knee Osteotomy Performed?
The main indication is malalignment of the leg that overloads a single compartment of the knee. Bow-leg alignment (varus) concentrates load on the inner compartment, while knock-knee alignment (valgus) drives it onto the outer compartment; over the years the cartilage on that side wears down and pain becomes persistent. Osteotomy is also performed together with cartilage repair, meniscus transplantation or ligament reconstruction, in order to protect the repaired tissue from the load that damaged the knee in the first place. If alignment is left uncorrected, the repair is exposed to exactly the same force again.
Who Is a Good Candidate for Knee Osteotomy?
Osteotomy is not appropriate for every arthritic knee. The best results are seen in patients whose wear is confined to one compartment, whose malalignment is measurable, who have retained good range of motion and stable ligaments, who want to stay active, and who do not smoke. The following situations make osteotomy unsuitable or increase its risk:
- Widespread arthritis involving more than one compartment of the knee
- Significant loss of movement or a stiff knee
- Inflammatory joint disease
- Conditions that impair bone healing, such as smoking, poorly controlled diabetes or advanced osteoporosis
- Uncorrected ligament instability, or an older patient with low activity demands
Preparation and Surgical Planning
Osteotomy is a measured operation, and the planning matters as much as the surgery itself. Standing full-length radiographs of the whole leg are used to map the mechanical axis; the size of the correction and the level of the bone cut are decided from those measurements. MRI shows the condition of the cartilage, menisci and ligaments. General health is reviewed beforehand, and stopping smoking is particularly important because it directly affects bone healing. Improving range of motion and quadriceps strength before surgery makes the rehabilitation that follows noticeably easier.
Osteotomy Techniques: HTO, DFO, Opening and Closing Wedge
The technique is chosen according to the direction of the deformity and the bone it arises from:
- High tibial osteotomy (HTO): the cut is made in the upper part of the shin bone to correct bow-leg alignment. It is the osteotomy most often performed in varus knees with medial compartment wear.
- Distal femoral osteotomy (DFO): the cut is made at the lower end of the thigh bone to correct knock-knee alignment, and it is preferred in valgus knees with lateral compartment wear.
- Opening wedge technique: the bone is opened from one side, the gap that forms may be filled with graft, and the correction is held with a plate and screws.
- Closing wedge technique: a wedge of bone is removed, alignment is corrected as the gap is closed, and the bone is then fixed.
The amount of correction is checked during the operation as well as in the pre-operative plan; the aim is to move load onto the healthier compartment without overcorrecting it. Where indicated, arthroscopic assessment of the joint or an accompanying meniscus or cartilage procedure can be carried out in the same session.
Anaesthesia and How Long the Operation Takes
The operation can be performed under general anaesthesia or under spinal or epidural anaesthesia; the choice depends on the patient's health and on the assessment of the anaesthetic team. A nerve block may be added to support pain control. Operating time varies with the technique, the complexity of the correction and any additional procedures performed at the same time. The hospital stay is usually short, and the timing of discharge is guided by pain control, safe walking with crutches and general condition rather than by a fixed number of days.
The First Period After Surgery
The priority in the early period is protecting the bone cut and keeping swelling under control. The leg is elevated, cold therapy and pain relief are organised, and gentle movement is encouraged. Weight-bearing is restricted according to the technique used and the progress of bone healing; crutches are standard at this stage, and the return to full weight is staged within the programme set by the surgeon. Measures against blood clots are taken, and ankle movements and controlled mobilisation begin early. Range-of-motion work starts as soon as the fixation safely allows.
Rehabilitation After Knee Osteotomy
Rehabilitation is one of the main determinants of the result. The programme begins with reducing swelling, restoring knee movement and reactivating the quadriceps muscle. As bone healing progresses, weight-bearing is increased and closed-chain strengthening, balance work and gait retraining are added. Strengthening the hip and trunk muscles helps to protect the corrected alignment. Progression is guided by pain, swelling, radiographic signs of healing and measured strength and function, rather than by a fixed calendar.
Returning to Work and Sport
Desk-based work can often be resumed relatively early, once pain is controlled and moving about is safe. Jobs that involve standing for long periods, heavy lifting or frequent use of stairs require a later return, because they depend on bone healing and on the capacity to take load. For sport, low-impact activity such as walking, cycling and pool work comes first; running, pivoting and contact sports are only considered once healing is complete and strength criteria have been met. These timescales differ considerably from one person to another.
Risks and Possible Complications
Osteotomy is a planned operation with its own specific risks. Possible problems include delayed healing or non-union of the bone cut, under- or overcorrection, irritation from the plate and screws, a fracture extending into the joint, infection, nerve or vessel injury, joint stiffness and deep vein thrombosis. Increasing swelling, warmth and calf pain are warning signs for a clot. Smoking is the most important modifiable cause of healing problems. Risks and realistic expectations should be discussed in detail before surgery.
Knee Osteotomy or Knee Replacement?
Osteotomy and knee replacement address the problem in different ways. Osteotomy redistributes load and preserves the patient's own joint, whereas partial (unicompartmental) or total replacement resurfaces the damaged compartment with an implant. Osteotomy can reduce pain and may postpone the need for replacement, but it does not reverse arthritis and no result can be guaranteed to last a lifetime. The outcome depends on correct patient selection, achieving the planned amount of correction, how extensive the cartilage damage is, body weight, smoking and adherence to rehabilitation. Joint-preserving surgery tends to suit younger, active patients, while replacement may be more appropriate when wear involves several compartments and activity demands are lower. Continuing non-surgical treatment remains an option in both groups.
When Should You See a Doctor?
After surgery, pain that increases and is not controlled by medication, redness, discharge or fever at the wound, calf pain with one-sided swelling, or numbness, weakness or a change of colour in the leg should be assessed without delay. Before surgery, one-sided knee pain that does not respond to non-surgical treatment and shortens your walking distance, together with a leg deformity that is becoming more obvious, is a reason to have your alignment measured. You can read more about the other knee problems covered here, and contact Assoc. Prof. Serkan Sürücü for an assessment.