Persistent joint pain is one of the most wearing conditions known to us. The surgeon is able to offer relief from pain that can often be dramatic and sustained. For each potential intervention he or she has to consider indications, contraindications, type of operation, timing of operation and medication.
Pain is the principal indication. When pain wakes the patient at night, his or her psychological and physical reserves wane quickly, and urgent action should then be considered. Often function is significantly impaired as well, but with surgery restoration of function is often disappointing, in contrast to the often dramatic relief of pain.
The radiological picture of the arthritis often poorly correlates with pain, and for this reason the radiograph is never an indication for surgery, but rather used to guide the surgeon as to details of surgery. RA is the inflammatory arthritis that most commonly requires the patient to resort to surgery. It is also polyarticular, therefore attention has to be paid to controlling the activity of disease before an accurate picture of pain in any one joint being considered for surgery can be obtained. In such polyarticular conditions the order of joint replacement becomes important (e.g. it is illogical to replace a painful hip or knee if the small joints of the feet remain the limiting factor). If patients have not been able to walk for 3 months because of pain in a joint or joints, referral for surgical opinion is urgent, as the chances of the patient walking after a 3-month period of not walking are small.
As with all operations contraindications are absolute or relative. Because many patients coming to surgery are often elderly they often have concurrent medical conditions, and therefore particular attention has to be paid to contraindications. Absolute contraindications are motivation and intercurrent infection. Motivation of the patient has to be present and realistic e.g. patients with poor co-operation due to poor motivation do poorly, and patients who want an operation to resume sport should be viewed with suspicion. Intercurrent infection precludes surgery, and particular attention to healing any signs of infection, especially possible sites of infection in teeth (dental referral), genitourinary system, gut and skin. Relative contraindications include:
- myocardial infarct within the last 6 months (risk of arrhythmias under anaesthesia);
- poor respiratory function, PEFR < 100 carries increased postoperative mortality and morbidity;
- prostatism, here there is considerable risk of postoperative urinary retention leading to catherisation, with the subsequent risk of urinary tract infection and risk of infected prosthesis;
- instability of the cervical spine, instability puts the cord at risk during intubation. If the cord is at risk, surgical fusion of the vertebrae should be performed before operating on other joints. Use of bronchoscopes to visualise the cords and act as a guide for the endotracheal tube (which can be sleeved over the bronchoscope) have much improved the safety of intubating the rheumatoid patient. Regional anaesthesia on limbs and epidurals has also improved safely.
Importantly, because the patients' quality of life is so affected by joint pain, they often opt for surgery even when significant risks are explained to them. There are essentially five options open to the surgeon:
- Joint aspiration - aspirating the effusion which develops as a result of synovitis. There can exist a large volume of fluid and it is this that stretches the capsule and causes pain. Simple aspiration will then temporarily relieve the pain.
- Joint debridement - joint debridement by arthroscopic wash out is claimed to be useful in early arthritis. This technique is thought to often settle the inflammation, possibly through removing the inflammatory particles in the joint, although this remains an unproven concept. Unfortunately, arthroscopy for arthritic knees is not supported by evidence of effectiveness and what evidence that does exist from high quality trials is that it does not work. NICE guidelines for Arthroscopic knee washout, with or without debridement, for the treatment of osteoarthritis http://www.nice.org.uk/nicemedia/live/11326/35856/35856.pdf states:
Referral for arthroscopic lavage and debridement should not be offered as part of treatment for osteoarthritis, unless the person has knee osteoarthritis with a clear history of mechanical locking (not gelling, 'giving way' or X-ray evidence of loose bodies).
- Synovectomy - involves removal of the synovium. This can be done arthroscopically. It is of controversial value in inflammatory arthritis. Chemical or radioisotope synovectomy can be useful, especially in limiting the recurrent effusions that can accompany RA.
- Osteotomy - is cutting the joint and realigning it. It is thought to reduce pain by redistributing the load, and possibly by modifying the blood supply to the articular cartilage. It can be useful in the young patient with hip pain and a good range of movement, and in young patients with a painful knee and deformity of the joint. Osteotomy is perhaps most commonly performed in the feet removing the metatarsal heads when they sublux downwards causing pain under the balls of the feet.
- Arthrodesis - is fusing the joint. It is a simple way of eradicating pain, but will also eradicate joint function. Patients are, therefore, intolerant of it and in the lower limb it tends to be used only in the hip and knee as salvage operations. Hip arthrodesis in a woman will limit sexual activity and restrict childbirth. The most suitable joint for fusion is the wrist, in part due to compensatory mobility of the joints above and below it. This underlines a principle of arthrodesis in that extra stress will be placed on joints above and below, which should, therefore, be healthy enough to cope. Indications to cervical fusion include cervical instability and pain and signs of nerve or cord compression.
- Arthroplasty is joint replacement. It remains the most effective and often to the patient the most preferable way of relieving pain. All joint replacements have a limited lifespan and therefore the timing of the operation is important.