What problems can occur with a total knee replacement?
Sometimes a total knee replacement can become problematic earlier than expected and may require revision surgery. Alternatively, you may be one of the many patients out there who has had a well-performed total knee replacement which has now failed or become problematic with the passage of time.
A problematic total knee replacement is often just that and the symptoms are often difficult to pin down and can be quite vague. Pain may or may not be present all the time – it may be slightly hot, warm or swollen. Your surgeon will examine you in the office and this often yields vital clues as to what the underlying diagnosis or cause could be.
What causes these problems?
The causes of a troublesome total knee replacement can be broadly divided into those intrinsic to the knee replacement or extrinsic to the knee replacement. Extrinsic hip or spine pathology can masquerade as knee pain. Therefore the treating surgeon needs to have a high index of suspicion before focussing on the knee replacement itself. Further, other systemic conditions such as metabolic bone disease/rheumatoid arthritis can all present with pain in the knee.
Causes intrinsic to the knee replacement: loosening, wear, mal-alignment, instability, stiffness (inability to fully bend or flex the knee), flexion contracture (inability to fully extend the knee), periprosthetic fracture, periprosthetic infection.
What investigations may be required?
The routine bloods, including ESR and CRP, weight-bearing long leg films are taken in both AP and lateral dimensions.
If an infection is suspected, then often a full infective workup is performed which comprises, in addition to the ESR and CRP, an aspiration and a bone scan +/- bone implant interface biopsies.
Can the problem get worse?
A long-standing problematic total knee replacement is unlikely to spontaneously get better.
It should be borne in mind that complications may result from a condition with or without surgery. Complications of non-operative treatment include worsening pain, increased stiffness, increasing deformity, adjacent joint disease, pain elsewhere, for example in the ankle, hip or lower back (due to abnormal gait and compensatory mechanisms). Complications can occur with any type of surgery.
Potential general complications: risks and complications of anaesthesia, bleeding, infection, blood clots, the need for further surgery, persistent pain, complex regional pain syndrome and wound healing problems, genito-urinary complications and cardiovascular complications.
Potential complications which are specific to the surgery mentioned above include nerve damage/foot drop, intraoperative fracture, stiffness, instability, loosening, wear, the need for revision surgery and non-resolution of symptoms, partial resolution of symptoms, leg length discrepancy.
These can be activity modification, painkillers and physiotherapy. Revision joint replacement surgery is a lengthy, technically demanding procedure and therefore should be performed by joint replacement specialists.
Patient fitness and physiological status should be rigorously assessed prior to committing to such a procedure. Your surgeon will sit down with you at the time and go through all the complications.
Due to recent significant biotechnological advances, there are a number of implants available each with their own biomechanical and fixation philosophies. It is important to select a reconstructive option which best suits the unique personality of your knee.
As mentioned this is lengthy, challenging and technically demanding surgery and there is now, due to biotechnological advances, a significant number of reconstructive options available. The variety of options and implant choice specific to your individual needs and reconstructive personality, will all form part of a shared decision-making process in the office.
Click here for more information on revision knee replacement surgery.
Postoperative period and recovery
Remember that below is a guide to recovery and that everyone heals at different rates and some people do take longer. Use this information to help you understand your condition, possible treatment and recovery. The timeframes given below are a minimum, it is important that you appreciate this when considering surgery as your healing and recovery may take longer.
After your operation, a routine enhanced programme of recovery will commence. The main parallel work streams of this programme are as follows:
Mobilisation is commenced on Day One. Gradually there is an increase in the frequency of transfers in and out of bed. This then progresses onto stairs and mobilisation to the toilet/shower and back. Before discharge, the patient is well rehearsed in the exercise routine and the knee should bend to at least ninety degrees. It is extremely important to remain well motivated and perform your exercises after discharge to fully optimise the range of motion of the newly replaced knee.
Will focus more on activities of daily living, functional transfers and adaptation of the home environment.
During the operation, spinal anaesthesia with local infiltration of anaesthetic around the hip is used. After the operation regular oral medication is then used. Ask for extra if required. Before discharge required prescriptions are provided.
It is perfectly ok to experience an ooze from the wound especially as one mobilises. Your dressing may require changing. Before discharge, the wound should be dry and arrangements will be in place for staple removal by your practice nurse.
Immediately after the operation intravenous (directly into the veins) fluids are given. Medications such as routine antibiotics are also given via this route. Urine output is carefully monitored. A bedside commode may be needed during the first postoperative day.
Normal diet is introduced as soon as possible. The urine catheter is removed once mobile. Bowel habit should also return to normal before discharge.
On the first morning after the operation ablutions are performed at the bedside. Showering is then gradually introduced – at first with assistance and then independently.
Stop using a stick once you feel comfortable to do so. Do not worry if this takes a bit longer since we all recover at different rates. Your surgeon will advise you at your follow up appointment.
Walk as far as your general health permits you to do so. If there are any concerns with shortness of breath or dizziness then stop and seek help. It will take a while before you get used to the knee replacement so increase your walking distance gradually.
Following a routine primary total hip replacement, you should be able to walk the same distance as before the hip became symptomatic. Ensure that you don’t become tired, breathless or dizzy.
A total knee replacement can remain slightly swollen and warm for up to many months after the operation. This is often part of the normal healing process. If the changes are sudden or associated with a temperature or a discharge from the wound consult your surgeon at once since this could represent infection.
Infection caught early often requires a joint washout with an exchange of any removable parts of the knee. Delayed or established infection often involves a staged procedure to help eradicate the bug.
In the early stages, the knee will try and stiffen up and scar down to its preoperative stage. Many soft tissue releases are performed during the operation to balance the knee. These releases will also begin to scar down. The best way to prevent this is to continue diligently with the physiotherapy programme.
Remain motivated and enthusiastic about the physiotherapy since at this stage it a crucial part of the recovery programme. If there are any setbacks in the first few weeks the scar tissue may consolidate and lead to a stiff knee. Such cases may require a manipulation under anaesthesia.