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Knee arthroscopy versus tibial osteotomy versus knee replacement surgery

22nd January 2018

If you have been diagnosed with knee osteoarthritis, you will no doubt be anxious to find out what your treatment options are likely to be. The number of procedures and methods which are used to treat and manage this condition can seem a little overwhelming at first. However, the treatment and interventions that your doctor will offer you depend on both the kind of symptoms you are suffering, and the severity of them. Treatment will also be affected by your general health and lifestyle, and whether you have already received treatment in the past.

Broadly speaking, your doctor will try to make sure he or she has exhausted all the suitable non-surgical options for you before they move onto more complex surgical procedures. However, if you have been treated with non-surgical interventions and they no longer respond, or if this route simply was not sufficient to restore your mobility and comfort, you may need to consider surgery.

Surgical solutions

Surgery for knee osteoarthritis can be one of three options:

  1. Tibial Osteotomy
  1. Knee Arthroscopy
  1. Knee replacement surgery

All these options have different benefits and are suitable for different requirements and scenarios. A treatment that has been deemed suitable for your friend may be completely inappropriate for you as all treatment options are dependent entirely upon your unique medical circumstances (even your social circumstances).

Knee Arthroscopy

This is a type of keyhole surgeryis used to diagnose problems within your knee joint. Most problems uncovered during the procedure can be dealt with by the surgeon at the same time. The procedure will normally be performed under general anaesthetic, although a spinal block can also be used, for patients who cannot tolerate anaesthesia. A small metal tube called an arthroscope is inserted through a small incision, and a tiny camera inside the tube sends images to the surgeon's screen, which enables him to see what is going on inside your knee.

Depending on what your surgeon finds, he can usually perform the corrective procedure there and then. This could involve lavage, which is when the surgeon uses a saline solution to clean and drain loose tissue from the joint spaces. Debridement is also often employed at this stage. This is a procedure that involves "hoovering" up excess tissue, which may be causing inflammation and pain. Debridement aims to leave the surfaces of cartilage smooth and clean.

Your surgeon may be planning to perform a meniscectomy, using arthroscopy to aid his performance of the procedure. A meniscectomy is needed if you have a tear in the meniscus, which is a fibrous cartilage membrane within the knee, which partially divides the joint cavity. A torn meniscus is a common injury, and can be acute or chronic. If your torn meniscus is severe, and cannot be adequately managed with physiotherapy, your doctor may consider you for a meniscectomy. This can be partial, if your age, general health and knee anatomy mean your menisci are likely to recover well from surgery. Alternatively, a full meniscectomy, where the malfunctioning meniscus is removed, will be offered.

Another way in which arthroscopy can be useful in treating knee issues is during the performance of a synovectomy. Synovial membranes are a type of connective tissue which line the joints. They secrete synovial fluid, which lubricate joints, making them operate more efficiently. However, if you have developed a tumour or arthritis, you may need to have a synovectomy to remove the affected synovial membrane in your knee.

Tibial Osteotomy

Tibial osteotomy is quite a different procedure to knee arthroscopy. Its aim is to address the root cause of osteoarthritis, instead of treating its symptoms. Tibial osteotomy involves identification of a misalignment which has led to the development of knee problems. This is then corrected, often by a wedge of bone being removed from the tibia, so that pressure on the edges of the knee joint is evened out. The bone will then bestabilised with metal plating.

Osteotomy is performed either to avoid knee replacement surgery, or to support other procedures like meniscectomy and synovectomy. Unless something is done to address the root causes of arthritis and related knee problems, cartilage resurfacing work such as lavage and debridement, and corrective procedures like meniscectomy and synovectomy will be unlikely to succeed in the long term.

How will your surgeon know if you need an osteotomy rather than an arthroscopic procedure or open knee surgery? If your legs have become bowed, and your weight is pressing upon your inner knee, causing significant pain and mobility impairment, the chances are that you will be offered an osteotomy.

Unlike arthroscopic keyhole surgery, the osteotomy will involve a couple of days in hospital. You will need to remain with your leg elevated for this time. You will also need to use crutches for a few weeks after the operation, and so you will not be discharged from hospital until your surgeon is confident you will be able to support yourself on these. You may be given a support brace to help ease mobility and promote healing, after your surgery. A physiotherapist will work with you to help you learn to walk with your realignment, and to maximise your knee's ability to heal, through gentle exercise and manipulation. You may not see the full benefits of the osteotomy for six months to a year after the treatment, and you will be left with a scar.

The "downtime" you will experience with osteotomy is greater than arthroscopic surgery. However, it may mean that you will avoid ever having to undergo a knee replacement, so in a way, it is worth regarding the osteotomy as a type of preventative treatment. The risks of infection and the chances of the operation failing to make improvements to your quality of life in the long term are far less than with a knee replacement.

Arthroscopic surgery can only be performed under very specific circumstances. If you have a particular injury, or a specific knee defect, arthroscopy will be used. However, if osteoarthritis has damaged your knee over many years, to the point where you are in pain even at rest, you may be eligible for a knee replacement. Your doctor will try to do everything he or she can to avoid this happening, for as long as possible. This is because a knee replacement implant will only last for twenty years. After this length of time, it is likely that it will need to be replaced or revised. This is why younger patients are often offered osteotomy first. However, osteotomy can unfortunately mean that, if the need arises later for a knee replacement, the surgery may not be possible, particularly if your surgeon had to cut through your medial collateral ligament during performance of the osteotomy.

Knee Replacement Surgery

So, if your osteoarthritis has progressed to the point where painkillers, diet and exercise make no difference, and all other treatment options have been exhausted, you will be offered a knee replacement. Knee replacement surgery can be partial or total. Partial knee replacement is also known as unicompartmental knee replacement, because only one area of the knee will be affected. The area in question will be determined by which part is most damaged. You may have medial, lateral or patellofemoral implants.

Partial surgery will be less invasive and will therefore have a shorter recovery time than a full knee replacement. However, a partial replacement runs a greater risk of needing revision than full replacement surgery. Your surgeon will weigh up the pros and cons of each option, and decide which is the best route to take, depending on your general health.

One of the downsides of knee replacement in general is that your surgeon will not know, until the time of surgery, whether or not your ligaments are healthy enough to support an implant. So you may end up waking up disappointed. However, rest assured that your surgeon only has your best interests at heart, and will talk you through plan B before you go into the operating theatre.

During partial knee replacement, your surgeon will open up your knee, whilst you are under general anaesthetic or a spinal block. Once he has decided which compartment to replace, he will remove the damaged parts and replace them with metal caps, attached using cement and separated by plastic "cartilage".

Your knee may be so damaged by osteoarthritis that your daily life has become difficult. Your surgeon may opt to perform a full knee replacement, as long as you are fit enough to make a full recovery. This operation takes three hours under general anaesthetic, and the recovery time is significant, with most people needing crutches for a number of weeks. Nonetheless, a prosthetic knee joint is likely to last twenty years before revision is necessary. This means that patients can get on with their lives without having to worry about more surgery in the near future.

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