HIP
Anatomy
The hip is a ball (femoral head) and socket (acetabulum) joint. The joint surfaces are covered by smooth articular cartilage which allows frictionless movements. Joint fluid (synovial) is produced by lining, which helps in lubrication and permits a wide range of pain free hip movements. The socket is further deepened by a tissue called labrum. This also improves the stability of the joint. Several muscles surround the hip joint which provide blood supply and facilitate movement. It is important that these muscle are rehabilitated after any hip operation so as to improve hip function.
Function
The hip joint has inherent stability due to its ball and socket shape. This helps in opitmising weight distribution and support the body in both static (standing) and dynamic (moving) postures. Upto seven times the body weight can be transmitted through the hip joints, particularly during high impact activities such as such as running and jumping.
Common Hip Conditions
Arthritis
There are two main forms of arthritis that affect the hip joint:
1. Osteoarthritis
This is a very common but severely disabling condition that affects huge number of people. The lining of the joint (articular cartilage) is lost and the bone is exposed on both sides. With the progress of this condition, extra bone (spurs or osteophytes) appear around the joint, further restricting the movement of the hip and causing more pain. Any further progression leads to more bone destruction and deformity. This results is more pain and severe restriction of movement. Muscles surrounding the hip can’t function properly, resulting in a limp.
2. Rheumatoid Arthritis
This is chronic inflammatory condition, which is known to have a strong genetic predisposition. This is a an autoimmune disease where body’s own defence system attacks the lining of the joint. Over time, severe pain and deformity ensues. This subsequently causes destruction of the joint with associated pain and stiffness.
Why does osteoarthritis happen?
Traditionally, osteoarthritis is divided into primary and secondary osteoarthritis. Primary osteoarthritis is generally due to genetic reasons, which may or may not be obvious. Secondary arthritis, on the other hand, could be caused by previous trauma, developmental conditions such as dysplasia or avascular necrosis.
Treatment Options
- Regular painkillers such as paracetamol, codeine, anti-inflammatories and sometimes stronger ones like morphine.
- Reduction of body weight, which will help by reducing the load going through the hip joint.
- Modification of lifestyle and reducing impact loading and avoiding high loads on the hip such as running and impact sports.
- Walking aids, again with a view to reduce load on the hip joint.
- Physiotherapy to maintain stability and muscle bulk around the hip.
- Sometimes, steroid injections are helpful particularly in early stages but they generally offer only a temporary pain relief.
When these measures do not control the symptoms then a reasonable option would be a total hip replacement.
How do I know when I should have a hip replacement?
As the hip arthritis progresses, the non-operative treatment options stop providing adequate pain relief. Most patients start having night pain and rest pain. Their sleep is disturbed and activities of daily living are seriously affected. It becomes difficult to go up and down the stairs and putting shoes and socks.
It is at this stage the patients start considering a hip replacement surgery.
WHAT IS A HIP JOINT INJECTION?
There are number of reasons for a painful hip joint, the most common of them being arthritis.
A well-performed hip injection provides a good pain relief. Sometimes, if there is a doubt whether the pain is indeed coming from the hip and not elsewhere (e.g. back), a diagnostic hip injection is performed to differentiate the correct cause.
How is it performed?
It is performed in a sterile (clean) room, often an operation theatre. Patient lies on his/her back and using X-ray guidance, local anaesthetic is placed around the hip joint. A fine needle is then passed into the hip joint, all under the guidance of the X-ray machine. Once the correct position is confirmed, a local anaesthetic with steroid is then injected into the hip.
How long will it last?
In most cases, a hip injection provides a good pain relief which can last up to an year, if not longer. Often the pain returns in which case a further injection can be performed or the patient is considered for a hip replacement surgery.
What are the risks of the procedure?
Every interventional procedure carries a risk:
- Infection – rare.
- Leg numbness and weakness – very rare.
- Temporary difficulty putting weight through the leg.
- Allergy to injected products .
Risks of steroids:
- Facial flushing – generally few days.
- Temporary alteration of your usual menstrual cycle (females).
- Temporary increase in sugar levels (diabetics).
What is the post procedure recovery protocol
- After the procedure, patients generally need to stay in the hospital for about an hour before they can go home.
- Patients generally need someone to collect them after the injection.
- There is no restriction in weight bearing.
- Continue with pain killing medications and reduce them as soon as the pain is controlled.
Patients keep a pain diary until they are seen back in the clinic.
What is a Total Hip Replacement
Once the non-operative treatment methods fail to provide the required pain relief, a hip replacement surgery is considered.
In total hip replacement, we have a reliable, versatile and successful option to help patients with hip arthritis. Around 100,000 hip replacements were performed in the UK. While the average age at surgery remains relatively unchanged, there are increasing numbers of elderly as well as younger and more active patients now undergoing this ‘life changing’ procedure.
The operation involves removing the head of the femur which permits the insertion of a new femoral stem. The socket is then cleared and a new socket is implanted. Thus a new artificial bearing surface is created. The principles of hip arthroplasty have changed little over the years. In essence, the femoral head is resected; a metal stem is implanted into the femur onto which a ceramic or cobalt chrome femoral head is impacted. This articulates with a polyethylene or ceramic ‘liner’, secured into the prepared acetabulu
Components can be fixed into the acetabulum and femur either using bone cement or via ‘uncemented’ ingrowth surface technology. Similarly, there are options in bearing surface combination and head size that can be selected in an attempt to optimise function, reduce potential for complication and to improve longevity. Differing protocols and regimes are used in rehabilitation. More recently enhanced rapid recovery programmes have been described.
Previous requirement for post-operative hip ‘precautions’ is now subject to debate. The outcomes following hip replacement surgery are extremely favourable. Patients are expected to return to an excellent level of function with a good range of movement and excellent pain relief following the procedure
The Operation
Patients generally have a general anaesthetic, or a spinal anaesthetic. The operation lasts between 1 and 2 hours. A cut is made over the side of the hip. The diseased bone is cut out and the implant is put in its place. These are then tested to ensure they work well. Lot of time is spent in ensuring that soft issues are balanced, hip joint is stable and leg lengths are nearly equal. The wound is then closed and glued together. This reduces the need to use clips which can be uncomfortable to remove
After the operation
Immediately after the surgery, patients are transferred to the recovery room and then the ward once they are stable.
Patients have:
- A drip inserted into a vein to administer fluids or blood.
- Blood tests and X-rays in the next few days after surgery.
General home advice
It is expected to have some pain but not the same sort of pain that was there before the surgery. This can last up to few weeks but not generally. It is often helpful to take painkillers, if needed. Swelling and bruising may also take up to 6-8 weeks to disappear – very rarely they continue up to 6 months.
The wound is normally checked at 2 weeks after the surgery. I use glue instead of clips so there is no need for anything to be removed. Also I believe it gives a more cosmetic scar. At this point providing the wound is fine then you can take a shower or bath with the wound covered in a waterproof dressing. It is important to comply with the physiotherapy advice which will improve your overall outcome after the surgery
Possible Complications
This is a very successful operation, but there are some risks associated with any type of surgery.
Complications can occur as a result of the anaesthetic, the hip replacement itself or as a general result of having a major surgery:
What are the complications of total hip replacement ?
Total hip replacement is one of the most reliable orthopaedic procedures performed in the NHS. The results are extremely good and the complication rate is very low. Still then, it is imperative to be aware of potential complications, which are:
Infection
Infection is a major concern after any operation. Fortunately, it is very rare following hip replacement surgery. Strict measures are taken to minimise this risk by using antibiotics and meticulous cleaning of the skin prior to the procedure. If the infection is superficial, it may be successfully treated with antibiotics. However, if the infection is deep in the joint then further surgery may be warranted to clear the infection.
Dislocation
Dislocation occurs when the femoral head dissociates from the socket. This is relatively rare. This risk is minimised by ensuring the implant at the time of surgery is in an optimal position and the soft tissue is tensioned appropriately. Post operatively, it is important to follow the advice from the physiotherapist to minimize any movements which can increase the risk of dislocation.
Thromboembolic disease
Blood clots can develop in the leg can cause undue discomfort and swelling which can impede rehabilitation. If these clots occur in the lung then these can prove more problematic and worrisome. In order to minimise these risks I encourage early mobilization and use blood thinning injections for four weeks after the operation. Furthermore, I insist on patients using thrombo-embolic deterrent stockings (TEDS) for six weeks.
Nerve injury
There are a number of nerves around the hip that are vulnerable during surgery. Injury can occur due to direct damage or due to placement of the retractors.
Bleeding
Bleeding is a complication of any operation. In order to minimise this, meticulous soft tissue dissection is performed to reduce excessive blood loss. However, occasionally a blood transfusion may be necessary
Fracture
There is a small risk of fracture. Depending on where the fracture is and the extent of it dictates the immediate treatment.
Leg length inequality
Leg length inequality can occur following surgery. I measure the legs prior to the procedure on the X-ray and use markers during the operation to ensure there is no leg length discrepancy.
Unfortunately there are some particularly complicated conditions in which leg length inequality is more common. If this is the case then this will be discussed with you prior to the procedure.
Wear/Loosening
Over time the hip can wear out and is likely to occur in any bearing surface over time when one surface articulates against another.
Loosening in the absence of infection (aseptic loosening) is perhaps the most common cause of failure requiring revision hip surgery.
Medical complications
These can include a heart attack, stroke, chest infection and bowel obstruction. Very rarely there is a risk of death
