Frequently asked questions and general considerations regarding hip and knee replacement surgery:
Q: When should I consider surgery?
Articular cartilage enables smooth, painless motion of joints. Arthritis and other conditions can result in loss of cartilage. Certain types of arthritis, particularly the inflammatory arthritides such as rheumatoid arthritis, respond very well to disease modifying medical treatment. These conditions should ideally be managed by a specialist rheumatologist.
Osteoarthritis (OA) is a degenerative joint pathology. In the early stages of the disease symptoms can usually be managed with physiotherapy, medication and/or injections, activity modification, and weight loss (if required). Disease modifying medications unfortunately do not alter the progression of pathology in OA. Surgical intervention is equally ineffective in slowing down the disease process in early OA, unless it addresses joint instability, severe deformity, or a mechanical problem such as a loose body in the joint or a large meniscal tear.
Once there is full thickness loss of cartilage (“bone-on-bone” arthritis), the joint will usually be very painful and stiff. In these cases, it is unlikely that non-surgical measures (such as simple pain medication and physiotherapy) alone will adequately address the pain and functional impairment, and joint replacement could be a very good option.
With the exception of fracture cases, the majority of joint replacements are elective procedures. This means that the operation can be scheduled at a time that will allow for preparations to be made and for any medical conditions to be optimised by your general practitioner or specialist physician if required, before the day of surgery.
Management of medical conditions such as hypertension or chronic obstructive airways disease should be optimised. Any dental problems or chronic wounds should be addressed first.
All chronic medications should be continued with a few exceptions. Blood thinners such as Warfarin, Xerelto (Rivaroxaban), Aspirin or Plavix (Clopidogrel) are usually stopped 7-10 days before surgery. This should be done in consultation with the relevant medical practitioner. In some cases, the risk of stopping the blood thinner is too high. In these cases, an alternative blood thinner might be required in the days before surgery. Sometimes it is advisable to delay surgery (such as shortly after coronary or other vascular stenting procedures).
Oral diabetic medications are usually omitted on the day of surgery (blood glucose level will be measured on admission).
Lifestyle factors that impact on general health should be optimised as far as possible before surgery. This includes considerations such as general strength and fitness, nutritional status, being over – or underweight and smoking cessation.
Q: How long will my joint replacement last?
A joint replacement should be viewed as a definitive, not a temporary procedure. It is expected to provide a long term solution to severe joint pathology causing pain and/or functional deficit. Joint replacements do not however always last for the recipient’s entire lifetime.
Early failures (within the first two years) are rare but can occur due to infection, fracture, or instability.
Materials used in the manufacture of modern joint replacement implants are resistant, but still subject to wear. The bearing (moving parts) of most joint replacement consists of polyethylene that articulates with a very hard, smooth metal or ceramic. These components can last for several decades. Polyethylene can become worn out, necessitating revision (exchange) of one or more components. Wear particles can cause osteolysis (weakening of bone), resulting in loosening of implants.
Data from joint registries show survivorship of joint replacement at 15 years, 20 years and 25 years after implantation as follows:
| 15 years | 20 years | 25 years | |
| Total Hip Replacement | 89.4% | 70.2% | 57.9% |
| Total Knee Replacement | 93.0% | 90.1% | 82.3% |
| Partial Knee Replacement | 76.5% | 71.6% | 69.8% |
Q: Are there less invasive options?
Optimal management of arthritis and other conditions affecting joints will vary depending on the type of pathology, severity of the condition, clinical signs and symptoms, as well as patient factors such as age, co-morbidities, and activity level. Often a multidisciplinary, multimodal approach is required.
Joint replacement surgery should not be considered in cases of early arthritis. Non-surgical management options should be considered in these cases and in some cases less invasive surgical intervention, such as arthroscopy, might have a role. Even in cases of severe, “bone-on-bone” arthritis, non-surgical management still has an important role to play, either in conjunction with surgical management, or even as standalone treatment. Please note that the medical management of inflammatory artritides, such as rheumatoid arthritis and crystalline arthritides (eg. gout) is beyond the scope of the discussion below.
Conservative (non-surgical) management options:
WEIGHT LOSS
Persons who are overweight place more load on their lower limb joints during weight-bearing and exercise than those who are at their optimal weight for their height. Reduction of load on the affected joint resulting from weight loss is likely to reduce pain associated with weight-bearing and activity. In cases where symptoms persist and surgery is still required, optimising weight reduces surgical and anaesthetic risk and improves post-op recovery.
PHYSIOTHERAPY
For patients with hip or knee arthritis, the therapist would usually start by identifying and addressing muscle weakness or imbalance. Strong core muscles help to stabilise the lumbar spine and pelvis. Strengthening the muscles that cross the hip and knee joints improves stability of the joints. Physiotherapy can help to regain strength and mobility of joints affected by arthritis or injury, or following surgery. The physiotherapist will also make sure that assistive devices, such as crutches, are used correctly.
Physio or occupational therapists also play a critical role as part of a multidisciplinary team in the management of chronic pain conditions.
ASSISTIVE DEVICES AND ORTHOSES
Assistive devices – such as crutches, frames, walking sticks, or hiking poles – are often used to reduce load on a hip or knee joint by transferring some of the load to the upper limbs. These devices are also often required to assist with balance. A physiotherapist and/or orthotist will be able to assist with advising on the appropriate device and correct adjustment and use of the device.
Rigid or hinged braces are often used in cases of joint instability due to ligamentous injury, or after soft tissue reconstruction surgery. A soft knee brace (i.e. a knee guard) does not contribute towards knee stability, but possibly assists with proprioception (position sense), and a snug fitting soft brace or bandage will often make an arthritic knee feel more stable.
Medial or lateral compartment offloading braces can be very useful in very specific instances where one side of the knee is affected by injury or arthritis but the other side is unaffected. These braces should be fitted by an orthotist.
Shoe inserts, modification of shoes, or specialised shoes might be required in cases of limb length discrepancy or angular deformity. Simple innersole inserts are available off-the-shelf, but more complex orthoses will need to be measured, and often custom made by an orthotist.
MEDICAL MANAGEMENT OF PAIN AND INFLAMMATION
Pain medication and anti-inflammatories can improve symptoms such as pain, swelling, and stiffness.
- Simple analgesia
Simple analgesics, such as Paracetamol, can be bought without prescription and are often effective for mild or moderate pain. Paracetamol works well in combination with other classes of pain medication and might reduce the requirement for stronger pain medications.
- Supplements
There are various over the counter arthritis medications. They often contain combinations of supplements, such as Glucosamine Chondroitin or Piascledine. These supplements have been shown to provide symptomatic relief to some people with arthritis. There is, however, no good evidence that there is any beneficial impact on the long term outcome of arthritis, despite marketing claims.
- Non-steroidal anti-inflammatory drugs (NSAID)
NSAID can improve pain, swelling, and stiffness by reducing inflammation. Despite the fact that osteoarthritis (OA) is a degenerative condition (and not primarily an inflammatory condition), NSAID do improve symptoms of OA.
NSAID can affect kidney function and should not be taken by individuals with renal impairment or when dehydrated. In a small percentage of the population, NSAID might cause cardiac arrhythmia. Prolonged use of NSAID can cause gastritis and even serious stomach or duodenal ulcers. Newer generation (COX II specific) NSAID have lower risk of gastro-intestinal side-effects.
- Opioids
Opioids are potent pain medications that can be used effectively for acute pain over a short period of time, and are often used post-operatively. Opioids can cause drowsiness, nausea, constipation, and itching. Prolonged use of opioids can lead to opioid tolerance (higher dose needed for the same effect) and dependence. Opioid overdose can be fatal. For these reasons, opioid use should be strictly supervised by a medical practitioner and should not be used for chronic pain.
- Second-line pain treatment options
Specific pain conditions or pain not responding to conventional pain management might respond to second-line treatment options. These often include medication from other classes, such as anti-depressants, anti-epileptic medications, or medications for neural pain. These medications should ideally be described by a pain specialist working in a multidisciplinary team.
- Injections
There are various options for intra-articular (IA) injections directly into a joint, or into soft tissues around the joint.
Steroid injection
Steroids are the most commonly-used intra-articular injections, and they are also the most potent anti-inflammatory medications. When injected directly into a joint or an area of acute inflammation, steroids can relieve symptoms for a few weeks. There is minimal effect on the rest of the body, and most of the potential side effects of systemic steroids (taken orally or administered intravenously) are avoided. Injections into the knee or surrounding soft tissue structures are usually administered in the consulting rooms. Injections into the hip joint or deep structures around the hip are usually administered under ultrasound guidance in a radiology suite.
Steroids are readily available and not very expensive. They can be combined with local anaesthetic. Duration of symptomatic relief is variable; typically just a few days, but often lasting for several weeks. Steroids are therefore not a long-term solution, but they do have a place as a once-off or occasional treatment. Steroids can also be very effective for extra-articular problems, such as bursitis or tendonitis. They do not improve the long-term outcome of the underlying condition, however, and should be seen as symptomatic treatment.
Hyaluronic acid
Hyaluronic acid is a vital component of articular cartilage. It can be injected in liquid or gel form into an arthritic joint. Initial optimism that it might slow down the arthritic process has not been confirmed in independent trials. The injections have been shown to provide symptomatic relief that seems to last longer than that of steroid injections. The injections are expensive and most pharmacies do not keep stock, but it can usually be ordered within a day or two. A small percentage of patients might develop a synovitis (inflammation of the joint) in reaction to IA hyaluronic acid injection.
Plasma rich platelets (PRP)
Small trials have shown PRP to be effective in various conditions where there has been damage to tendons, ligaments, or cartilage. PRP is extracted from the patient’s own blood. The risk for adverse reaction is therefore minimal.
Stem cells
Stem cells are pluri-potential cells. These are cells that have the potential to develop into various types of tissue (including cartilage). Unfortunately stem cells do not automatically repair damaged cartilage, and the efficacy of intra-articular stem cell injections has not been supported by independent research.
Do you have any further questions? Do not hesitate to contact Dr Reid’s practice for more information: admin1@hipandkneearthroplasty.com