Introduction

Osteotomy, which literally means cutting bone, is an operation to change the alignment of a bone. In the lower limb it is most performed for arthritis involving 1 compartment of the knee joint. An osteotomy is typically used in a young or active person who is less than 60 years of age. Older or less active patients may undergo some form of knee replacement.

During an osteotomy the surgeon may remove or add a wedge of bone to your tibia, which is your shin bone, or the lower thigh bone called the femur. This shifts the weight-bearing point in the knee from the non-damaged portion to the undamaged portion of the joint. If the surgery is to include a bone graft, the added bone will be from a bone bank (donor) or some form of bone substitute. This will be discussed with you prior to the surgery.

Osteotomies to realign the bone may have 2 specific goals.

1. To improve the pain associated with the arthritis

2. To delay the need for a total knee replacement to an age where the prosthesis will have a greater chance of lasting the length of the person's life

Occasionally an osteotomy can be performed as part of the treatment for knee ligament reconstruction, in association with a repair to the articular cartilage or repair of some other tissues such as ligaments.

Preparation prior to surgery

In order to prepare for osteotomy surgery, a number of things should be considered.

Pre-existing medical conditions

You will be asked about your medical history. It is important that you accurately inform your specialist of any conditions affecting your heart, lungs, blood pressure, kidneys, or circulation.

It is also critical to inform your doctor of any conditions that may affect your immune system, such as diabetes. Patients will be assessed in a preadmission clinic prior to the surgery. The purpose of the preadmission clinic is to;

1. Obtain a thorough Merit medical and surgical history

2. Conduct any blood tests, x-rays, ECG, skin swabs and other investigations

3. Understand needs and answer your questions

Medications

10 days prior to surgery some medications may need to stop. These may include aspirin, nonsteroidal anti-inflammatories, garlic capsules and fish oil. If you are taking blood thinners such as aspirin, Plavix or warfarin, these may need to stop but will likely need to be done in conjunction with advice from either your general practitioner or another specialist, such as a cardiologist. It is critical that you inform your specialist if you are taking these medications.

Skin care

It is vitally important that you have no cuts, scratches or skin infections as these increase the risk of infection and may lead to your surgery being postponed. Do not wax or shave your legs in the week prior to surgery.

Smoking

It is recommended to cease smoking for at least 6 weeks prior to surgery. People who smoke have an increased complication rate for events such as a DVT, non-healing of wounds, bone infection, and other more serious events such as stroke and heart attack complications.

Dental hygiene

Infections in other parts of the body can cause bacteria to enter your bloodstream and this can lead to a prosthetic joint infection. To reduce your risk of infection, major dental procedures should be done prior to you having any joint replacement surgery. If dental surgery is required following a joint replacement you must inform the dentist that you are required to take a preventative antibiotic to minimise the chance of a blood-borne infection.

The day of the surgery

Bring all x-rays and scans with you to the hospital. You are usually admitted to the hospital of surgery where you will meet the anaesthetist who will discuss your medical and anaesthetic history. The anaesthetist will also discuss the type of anaesthetic being used during your procedure, which is most commonly a general anaesthetic. You will be giving fasting instructions. It is critical you adhere to the fasting instructions. Deviation from any instructions may result in cancellation of surgery.

On admission, your leg is washed, shaved, if necessary, prepared with antiseptic and wrapped in a sterile towel. This helps prevent infection and helps identify the correct site for surgery. Prior to the surgery you will be repeatedly asked to confirm which side will be operated on. These are important checks for the hospital staff to perform.

The surgery

 Osteotomies are carried out with the assistance of either a computer navigation to accurately correct the alignment or via the use of a patient's specific cutting guide designed using careful preoperative individualised planning. Prior to surgery, if navigation is used, pins will be inserted into the femur and tibia and connected to a computer via infrared cameras. Keyhole surgery will be performed to assess the joint surfaces, define the landmarks for the computer assistance and deal with any intra-articular pathology such as loose bodies or meniscal tears. Following the arthroscopy, leg alignment is changed by cutting the tibia just below the level of the knee usually and hinging through a point to insert a wedge of bone or by cutting a wedge of bone out. This is then stabilised by placing a metal plate and screws which will stay on the tibia. The size of the wedge and the correction is determined by commendation of preoperative planning and by the computer navigation or via the use of patient-specific cutting guides.

An opening wedge osteotomy is much more common than a closing wedge. The wedge shape is filled with either bone from the bone bank or tissue bank, or a bone substitute.

At the conclusion of the procedure local anaesthetic is infiltrated into the wound to reduce pain. Dressings are applied along with a brace. Typically, patients are allowed to partially weight bear on the leg, 50% weight-bearing for 6 weeks in a range of motion of full extension to 90 degrees knee flexion. In some instances, an osteotomy may be performed on the femur. This is typically done through an incision on the outer aspect of the knee and a similar process is followed for determining the size of the correction.

After Surgery

Whilst there is some discomfort after an osteotomy, it is not a major hurdle and is usually dealt with via oral analgesia. On the first post-operative day, the patient will typically walk with either the use of a frame or crutches, usually touch or partial weight-bearing (20 or 50%). In some instances, no weight-bearing may be possible for the first 6 weeks, but your surgeon will inform you if this is the case.

You will be seen by physiotherapist to teach you how to use the crutches. The brace will be unlocked in a range of motion of full extension to 90 degrees flexion. Typically, you will remain in hospital anywhere from 1 to 3 days until you are safe to be discharged on crutches.

Pain relief is provided in the form of oral analgesia. Post-operative pain after an osteotomy is typically not severe. The physiotherapist will assess you walking with crutches. You will be permitted to place some weight on your foot, but the amount will be determined by the operation. Please refer to the surgeon’s instructions regarding this. The knee will typically be allowed to bend from full extension to 90 degrees flexion for the first 6 weeks.

Weight-Bearing

After surgery, weight-bearing will be determined by any meniscal and cartilage injury or associated ligament surgery. Typically, patients are allowed to 50% weight-bear with crutches. If weight-bearing is permitted, crutches are still required until the quadriceps have regained control of the knee and walking can be performed safely. Patients typically go home the day after surgery.

Bandages and Dressings

On the first after surgery, the bandages on the knee are removed and a compressive bandage called a tubigrip, which has been placed underneath from mid shin to mid-thigh, is left in place. The dressings are kept dry and in place until the wound review, which is performed with the surgeon typically 10 to 14 days after the surgery. If the bandaging becomes soaked either with blood or otherwise the patient should return either to the clinic, or if this is not possible, to the hospital to have the dressings changed.

Stitches in the incisions may be dissolving, however are sometimes still removed between days 10-14 on a return visit to consultation for a wound review. The knee needs to remain dry. Swimming, bathing, spa’s, sauna etc. is not allowed until wound healing is confirmed. To shower, a water-proof sleeve that fits over the knee can be purchased from the chemist.

• Waterproof dressings have been applied to the skin that allow patient to shower

• Small amounts of ooze that can be seen on the dressings are a normal part of the routine post operative experience and are of no concern.

• If there is a larger amount of blood that leaks from a dressing, this is very rare. Over wrap the area with 2 x extra crepe bandages with a firm pressure. Rest the knee and avoid excessive walking. Contact Dr Shatrov' Practice Manager at the next available time so an urgent review can be arranged. 

Exercises

Exercises to activate the quadriceps and gluteal muscle are performed, and calf pumping exercises encouraged to circulate blood throughout the leg. The focus initially should be on achieving full extension of the knee and activating the quadriceps muscles. Flexion of the knee is typically encouraged as well but may be limited depending on some of the associated injuries or surgery that your knee may have required such as meniscal surgery.

Medications

A blood thinning medication is often prescribed for two weeks following surgery to reduce the risk of DVT’s. 

Pain relief is prescribed and typically involves the following. 

• Paracetamol 1 g every 6 hours (if the patient does not have either an allergy to this medication or pre-existing liver disease) 

• A nonsteroidal anti-inflammatory which is typically either 1 of celecoxib, meloxicam or Voltaren. This should not be taken if the patient has kidney problems, high blood pressure, may be pregnant or has reflux. 

Additional pain killers are often prescribed but depend on a variety of factors including the anaesthetist’s preference, the patient's preference, and pre-existing medical conditions as well as their medication history. Local anaesthetic is typically injected around the incisions and graft harvest site at the time of surgery and often wears off 12 to 18 hours after being inserted. This is often accompanied with gradually increasing pain at that time. Medications are to be purchased upon discharge from the hospital. Ongoing scripts if required should be sort from your GP.

Driving 

Driving is not permitted until sufficient muscle control has been regained to allow for emergency breaking. The length of time that this takes varies depending on the surgery and can range from 1 week to 3 months. Driving is also not needed whilst taking certain medications. For more information about this please consult either your general practitioner or your orthopaedic surgeon.

Showering

Showering is permitted but the wound needs to remain dry. A sleeve can be purchased from some chemists. Alternatively, a bag can be wrapped around the leg in order to keep it dry.

Bracing

Bracing is often required after an osteotomy, and if needed will be fitted at the time of surgery and in hospital. Typically, it is worn for 6 weeks post-surgery, including when sleeping and will allow a range of motion from 0° to 90° flexion.

Physiotherapy

A critical component of osteotomy recovery is a supervised rehabilitation program with a physiotherapist. Physiotherapy should be arranged prior to surgery and the details of the physiotherapist shared with the surgeon so they can communicate as required during your recovery. The frequency and duration of therapy will be determined by the physiotherapist but should commence within a week of the surgery.

Rehabilitation

Following discharge from hospital you will see Dr Shatrov 1-2 weeks later to check the wound. The brace is worn for a total of 6 weeks, in conjunction with using crutches. The weight bearing will be allowed as above. At the 6-week mark x-rays will be taken to determine if bone healing is sufficient and at this point you will be allowed to increase your weight-bearing.

Rehabilitation with a physiotherapist is commenced 6 weeks after surgery. This will aim to restore the range of motion, improve muscle activation particularly in the quadricep and gluteal muscles, reduce the effusion, and to help normalise you’re walking. It takes most patients about 6 months to fully recover from an osteotomy. It is possible to resume a sedentary office-based job 2 weeks after the surgery on crutches. It is usually 3 to 4 months before physical work is possible, and anywhere from 6 to 12 months before sport can resume. If the osteotomy is performed on your driving leg, you will not be allowed to drive for 6 weeks.

Potential Complications and Risks

Infection

Although great caution is taken before, during, and after surgery, infections can occur in approximately 1 to 2% of cases. Deep infection in the bone is rare but if this occurs and is untreated, serious problems can follow. If an infection occurs, please contact the rooms immediately or present to the nearest emergency department. In the presence of a deep infection, surgery may be required to irrigate and close the wound, and long-term antibiotics may be required. Any fever, wound redness, swelling or increasing pain should be reported to Dr Shatrov.

Blood clots

Deep vein thrombosis, or DVT, can occur when the veins in the leg form blood clots which, in some instances, can dislodge and travel to the lungs, causing something called a pulmonary embolism. A pulmonary embolism, whilst very rare, can be fatal and this is to be taken seriously. The following steps will be taken to avoid blood clots: 

• Early mobilisation

• The use of compression stockings

• Foot and ankle pumping exercises every hour whilst awake to increase the blood flow and reduce venous stasis in the leg

In some instances, you will be given a blood thinning medication post-surgery. If you develop abnormal swelling, redness, pain or tenderness in the calf muscle, chest pain or shortness of breath, the symptoms should be immediately reported to Dr Shatrov.

Poor bone healing

In approximately 2 to 3% of patients the bone may not fully heal or may change position whilst healing. This is monitored by x-rays. Occasionally further surgery may be required to improve or expedite bone healing. Poor bone healing is much more common in people who smoke or who have other medical comorbidities that may impair healing.

Nerve and vessel injury

Several major nerves and blood vessels which supply the legs are in the vicinity of the surgery and are at risk at the time of the operation. This is an extremely rare complication. More commonly, a couple of small nerves that supply the skin in the region will be divided at time of surgery and a small numb patch in the lower leg is common after the surgery. This is typically permanent. In the case of nerve injury, whilst incredibly rare it is possible that if this was to occur that the patient may lose the inability to move the foot up and down.

Haematoma

A haematoma can occur post-surgery. A haematoma is a collection of blood. It may occur in the knee after surgery. It is more common if the patient takes blood thinners. It can be a source of pain and stiffness and can be treated by aspiration or via the use of ice and compression.

Other possible complications

Initially, it is common for people to experience difficulty improving their range of motion in the knee and experience some stiffness, particularly extending the knee. This is the purpose of physiotherapy after surgery.

Hardware irritation

As a result of surgery, it is expected that most patients will experience some discomfort from the presence of the plate which sits beneath the skin. For this reason, it is an expected outcome that the osteotomy plate will need to be removed eventually.

Further progression of osteoarthritis

It is important to understand that the surgery will not take away any pre-existing osteoarthritis. It is an expected outcome following a high tibial osteotomy for an osteotomy of the lower leg, but eventually at some point the patient will progress to needing further surgery to deal with the symptoms of osteoarthritis.

Results

Most patients feel improvement in pain relief and function of the knee following an osteotomy. In less than 10% of cases patients feel that they have not improved and in 1 to 2% of cases they feel that they have been made worse. The improvement seen following an osteotomy typically lasts for a variable period of time depending on how well the patient cares for the knee and the degree of the damage already done  by the severity of the arthritis that is already present. In over 70% of cases, patients will not require further intervention in the leg for more than 10 years.

Knee replacement surgery following an osteotomy

Replacing a patient's knee who has previously had a high tibial osteotomy does increase the complexity of the total knee replacement to be performed. However, the results achieved are better than redoing a previous total knee replacement and the results are still usually very successful. Results from the National Joint Registry show that the outcome of a post-osteotomy total knee replacement is similar to that of a primary total knee replacement.

Dr Shatrovs Publications on Osteotomies

1. Erard J, Schmidt A, Batailler C, Shatrov J, Servien E, Lustig S. Higher knee survivorship in young patients with monocompartmental osteoarthritis and constitutional deformity treated by high tibial osteotomy then total knee arthroplasty compared to an early total knee arthroplasty : a comparative study at a minimum follow-up of ten years. Bone Jt Open. 2023 Feb;4(2):62-71. doi: 10.1302/2633-1462.42.BJO-2023-0002.R1. PMID: 36722347; PMCID: PMC10011927.

2. Increased Knee Joint Line Obliquity following High Tibial Osteotomy Associated with Medial Meniscal Root Tear: A report of two cases and a review of the relevant literature

3. Ravi T Rudraraju , Jobe Shatrov , Brett A Fritsch Osteotomy Complications: Prevention and Cure. Asian Journal of Arthroscopy | ISSN 2456-1169 | Available at www.asianarthroscopy.com DOI:10.13107/aja.2021.v06i02.000

4. Cazor A, Schmidt A, Shatrov J, Alqahtani T, Neyret P, Sappey-Marinier E, Batailler C, Lustig S, Servien E. Less risk of conversion to total knee arthroplasty without significant clinical and survivorship difference for opening-wedge high tibial osteotomies in varus knee deformities at 10-year minimum follow-up compared to closing-wedge high tibial osteotomies. Knee Surg Sports Traumatol Arthrosc. 2023 Apr;31(4):1603-1613. doi: 10.1007/s00167-022-07122-z. Epub 2022 Aug 29. PMID: 36038667.