Knee realignment or osteotomy surgery

X-ray showing a high tibial osteotomy fixed with a metal plate and screws.

Double Osteotomy HTO and DFO

Overview

Osteotomy surgery involves cutting and re-aligning the bone (usually shin bone/tibia) in order to re-distribute the weight going through the knee. Re-alignement can be achieved by either taking a slice of bone out of the tibia (shin bone) or femur (thigh bone) close to the knee joint (closing wedge) or opening a gap in the bone (opening wedge).

A significant number of patients have isolated damage to one side of the knee whilst the other side of the knee remains healthy. Because most patients are slightly bow-legged it is much more common to wear out the medial (inner) portion of the knee. Here an individual will complain of pain which is predominantly felt on the inner side of the knee. The reverse to this is an individual who is "knock-kneed" who is more likely to sustain wear and damage to the outer (lateral) compartment of the knee.

In the UK the most commonly carried out procedure for severe wearand tear is a partial or total knee replacement. We know from our follow up studies that young people tend to do less well with a knee replacement than more elderly patients. Where a patient is suitable an osteotomy may represent an excellent alternative to knee replacement surgery.

The key to this procedure is patient selection. Suitability for osteotomy surgery depends on a number of factors which include: Age, activity level, isolated damage to one side of the knee and leg alignment. Several investigations are required for this surgery including full length xrays of the leg to assess the alignment, an MRI scan and often a key-hole procedure (arthroscopy) to inspect the knee and ensure the damage is confined to one side of the knee. A computer software programme is then used to calculate the amount of re-alignment required at the time of the operation.

In order for this operation to succeed it is extremely important for the patient not to smoke. If patients are smokers they must stop smoking at least two weeks prior to the surgery and remain non-smokers for a minimum of three months post-surgery. The toxins in tobacco smoke have a hugely negative impact on blood supply to the bone and can prevent or significantly delay bone and wound healing.

Watch: Patient Walking 3 Weeks Post HTO

Illustration of a distal femoral osteotomy held together with a Tomofix plate and screws. Re-produced with permission from Synthes.

Distal femoral osteotomy (DFO)

When a patient is knock-kneed as opposed to bow-legged, the realignment is usually carried out on the lower end of the thigh-bone (femur). As with tibial osteotomy the bone is cut in a controlled fashion and realigned by a pre-determined amount as explained above. Once again the surgery is carried out under X-ray guidance to ensure accuracy and safety of the procedure. The bone is fixed in its new position with a plate and screws. In-patient stay is again 2-3 days. Rehabilitation is slightly slower and rather than commencing immediate full weight bearing patients use crutches and have protected weight bearing for 6 weeks.

Illustration of the Tomofix plate, used to rigidly hold a high tibial osteotomy. Images re-produced with permission from Synthes.

High tibial osteotomy (HTO)

This is the most commonly carried out osteotomy. The procedure involves cutting the shin bone/tibia near its top and opening a gap in the bone. The amount of opening is determined prior to surgery using a specialist computer software programme. We at Hampshire knee are one of the few units that have access to this technology. We have been involved in the development of the next generation of software, which will become available in the early 2011.

During the procedure the gap is opened by the pre-set amount. To further increase the accuracy of this procedure X-rays are taken intra-operatively to ensure the accuracy of the re-alignment. A revolutionary plate is then used to fix the realigned tibia in the new position. This plate is very strong and in most cases patients are allowed to take full weight through the operated leg the day after the operation. No brace or plaster is required following surgery and you will use crutches for the first 4-6 weeks, until the knee feels strong enough for you to walk unaided. The plate is designed not only to allow early mobilisation but also to encourage bone healing. The gap which is created rapidly fills in with new bone. Occasionally the plate causes some minor irritation, in which case it is removed a year or so after the osteotomy.

At the end of the procedure a large volume of a local anaesthetic solution is infiltrated in and around the knee to minimise pain. Patients are usually discharged 2-3 days following surgery. Driving is not possible for 4-6 weeks following surgery. On average patients can get back to office type work at 6 weeks and manual work by 12 weeks following their osteotomy.

Basingstoke continues to excel in knee osteotomy surgery. The 4th National Osteotomy

Masterclass course was held at the Ark Conference centre at the North Hampshire hospital in November 2010. This course was attended by senior UK consultants, wishing to learn about this procedure. The faculty included some of Europe's leading knee surgeons, who are considered world leaders in osteotomy surgery. This relatively uncommon operation in the UK is very much growing in popularity. In appropriate patients this operation can significantly reduce pain, improve knee function and may represent an excellent alternative to knee replacement surgery, which is the vogue at present in the UK. Mr Wilson, the senior surgeon at Hampshire knee, is currently working with Arthrex on development of new instruments for this procedure, which will be available towards the middle of 2011.

Example of patient following Opening Wedge HTO

Pre operative xrays - no space on medial side of knee with well preserved lateral compartment

Pre Operative X-ray of High Tibial Osteotomy

Intra-operative Images:The osteotomy is opened

Osteotomy being opened

Osteotomy is opened

Fixation & change of weight bearing line

An osteotomy fixation

Long leg alignment

Aligment of a leg pre-op

Aligment of a leg post-op

5 weeks post op images

Full Stretch

Full Flexion

Knee Wound

Standing Alignment

Watch: Interview 5 months Post High Tibial Osteotomy

Watch: Walking 6 weeks after High Tibial Osteotomy

Example of patient following A Distal Femoral Osteotomy

Pre operative xrays

Post Operative X-ray of High Tibial Osteotomy

Intra-operative Images - the osteotomy is opened and held with a strong plate

Osteotomy being opened

Osteotomy is opened

Post Operative xray

An osteotomy fixation

Long leg alignment

Aligment of a leg pre-op

Aligment of a leg post-op

Post op images

Full Stretch

Full Flexion

Knee Wound

Standing Alignment

Watch: Patient Walking 3 Months Post Femoral Osteotomy

To find out more about osteotomy, please read Mr Wilson's articles on the knee guru website:

Click here to see Mr Wilson's lecture on knee osteotomy on Knee Guru

Off Loading Braces

It may be that we can reduce your pain by using an off loading brace. The way it works is to redistribute weight from the damaged side of your knee to the good side. Usually these braces are uncomfortable and poorly tolerated by patients.

The Ossur brace is comfortable and light weight. It only needs to be worn during the day when you are up and about. It can produce excellent reduction in pain.

Please discuss this option with a member of the team.