Causes of hip pain

Osteoarthritis

In health, the hip joint surfaces are perfectly smooth, allowing almost friction-free movement. Osteoarthritis causes the articular cartilage joint lining to become worn-away. Often there is no obvious cause for this (termed "primary osteoarthritis"). This tends to occurs around middle age in people with a strong family history of arthritis. Secondary osteoarthritis occurs if disease conditions (such as dysplasia or  Perthes disease) result in abnormal anatomy and increased mechanical loading to the joint. If osteoarthritis becomes severe,  the bone surfaces rub directly against each other causing an uncomfortable grinding sensation. Pain is usually felt in the groin and thigh. There may be stiffness and a sensation of instability. Walking, exercise and deep flexion tend to aggravate symptoms. For some people, activity modification, pain killers and weight-loss may help, whilst for others, a total hip replacement will be more effective.

Avascular Necrosis

Healthy hips require a good blood supply. If this is disrupted, the bone may soften and die, causing collapse of the femoral head. This typically causes very severe pain with weight-bearing. There are many causes for this condition including exposure to steroids, trauma, high intake of alcohol and certain blood disorders (including sickle cell disease). In about 25% of cases, no obvious cause can be found. X-rays may appear normal in the early stages of the disease though the diagnosis can be reliably made using MRI scanning. If the condition is not advanced, avoidance of risk factors together with surgical procedures to restore the blood supply can be helpful. If the damage to the bone within the femoral head is advanced, replacement of the hip may be needed.

Femoral Neck Fracture

The femoral neck region (the upper part of the thigh bone just below the hip) is susceptible to fracture in patients who have weakened bone due to osteoporosis. This form of "broken hip" is usually seen in elderly female patients. Surgery is invariably required to either fix the fracture back into place or to replace the joint. Although less common, fractures in this region may also occur in young and fit people in association with physical training. So called "Stress fractures" of the femoral neck may present with progressive pain associated with a high level of physical activity (such as training for a marathon). Importantly, a simple X-ray may miss the diagnosis and a MRI is usually needed.

Femoroacetabular Impingment & Labral Tears

It is now recognised that certain variations of normal hip development can cause impingement between the outside of the hip socket and the femoral neck. Pain is initially felt when the hip is deeply flexed and the leg is brought in across the body. With time, stiffness may progress and damage to the joint itself can occur. Hip impingement may cause a tear at the cartilage rim of the socket (the "labrum") and with time may also result in wear of the joint surface.

Hip Dysplasia

Hip dysplasia refers to a broad spectrum of developmental abnormalities of that may cause hip pain. At one extreme is a situation whereby the femoral head develops outside of the socket (congenital hip dislocation). This results in shortening of the leg and an obvious limp. Thanks to screening of newborn children, this condition is now uncommon. A less severe form of dysplasia results in a shallow pelvic socket. The resulting abnormal loading of the joint may cause pain and osteoarthritis.  Because the abnormalities may be subtle, the diagnosis is sometimes missed. Surgery to form a more normal socket can reduce the chance of the joint wearing-out early


Trochanteric Pain

Pain in the buttock and upper thigh is often due to inflammation of the large muscles that stabilise the hip and straighten the leg. There may also be inflammation at the tip of the thigh bone where the the tendons of these muscles inset. Often pain is felt when lying on the painful side. Sometimes symptoms come on after a change in exercise regimen or following trauma. A range of treatments include rest, anti-inflammatory medications, stretches, injections and shock-wave therapy. 

Hip treatment without surgery

Medications

For many people, occasional use of a simple pain-killer such as paracetamol may be all that is needed to keep their symptoms under control. Non-steroidal anti-inflammatories (such as ibuprofen) are often more effective but can have significant side-effects. Stronger pain killers containing opiates can become addictive and are best avoided. Dietary supplements such as glucosamine tend to not make any difference. Although not part of mainstream medicine, many patients report finding turmeric helpful. 

Exercise

Often patients seek help when their hip pain makes maintaining their active lifestyle difficult. There is however good evidence that regular low-impact exercise such as cycling, swimming or pilates can help maintain hip flexibility and stave-of surgery. If on a bike, set the seat high with the handle-bars not too far forward. Swimmers may find breast-stroke uncomfortable but crawl tends to be well tolerated. Higher impact sports like road running or squash can irritate the hips; moving over to racquetball or an inclined treadmill can help. 

Physiotheapy

If the hip is very worn and painful, treatment with a physiotherapist will not cure the problem. However, working with a therapist will help build core strength, making some activities of daily living easier. This will also facilitate your recovery if surgery is eventually needed. For other hip conditions such trochanteric pain syndrome, physical therapy represents the mainstay of treatment.

Walking aids

Most people find the prospect of using a walking stick fairly unattractive (though if you do consider using one, it is more helpful in the opposite hand). A pair of Nordic hiking poles can be an effective  way of taking the load off painful joints when takling more challenging terrain. Well cushioned trainers usually help whilst heels can aggravate. 

Shockwave therapy

This form of non-invasive treatment is used to treat chronic soft-tissue inflammation. Although the mechanism of action is not well understood, the mechanical pulses are thought to stimulate healing. This treatment can be used trochanteric pain (at the side of the hip), as well as other conditions such as tennis elbow, patella tendonitis and plantar fasciitis. The results are not instant and treatment may be uncomfortable.

Injections

Injections can be used in the trochanteric area, around the major hip tendons or into the joint itself. Often ultrasound or X-ray is used to locate the exact spot. If the cause of pain is uncertain, injections of local anaesthetic alone may be used to clarify the diagnosis. More commonly, injections will include steroids and/or joint lubrication gel (viscoelastic supplementation).

what type of hip replacement is the best?

Femoral Stem

Many hundreds of combinations of hip replacement components are currently in use and certainly no single prosthesis is the best choice in every situation. Whilst much emphasis is often placed on the type of implant, the most critical success factors are; i) precise pre-operative planning of implant positioning and dimensions; ii) meticulous surgical technique to deliver the planned reconstruction.


For every individual, the surgeon must make their recommendation taking into account the patients age, their anticipated activity level and their specific bone characteristics (strength, size and shape). The surgical strategy is then exactly defined by making a series of  planning measurements using either X-rays or CT scans.


The stem can be anchored to the bone either using polymethyl methacrylate cement or a porous surface treatment that bone grows onto. Whilst  hip replacements were traditionally fixed with cement, over the last decade,  uncemented stems has become more popular, especially for younger patients. The attraction of uncemented implants is that a potentially life-long bond with the patients bone can be formed. Uncemented stems, are also particularly suited to minimally invasive surgical techniques and may incorporate "bone conserving" designs. Cemented stems have demonstrated excellent longevity and a lower risk of fracture during surgery. When the bone is weak (osteoporosis), it may be sensible to use cement.


Arguments as to which form of implant fixation is superior have raged for decades. However, highly reproducible outcomes are consistently observed when using both cemented and uncemented implants provided that the "best in class" prostheses are used. In the U.K, the clinical evidence showing the long-term reliability of hip replacements is rated by the "Orthopaedic Data Evaluation Panel" (ODEP). Currently the highest ODEP rating is 13A*, indicating that robust clinical data exists beyond 13 years with a revision rate <5% after the first decade. For the majority of cases, Mr Bartlett uses exclusively implants with the best clinical track-record (including "13A*" rated "Taperlock", "Corail" and "CPT"). Occasionally, conventional prostheses do not match the patients anatomy well and in such circumstances a bespoke implant may preferable (e.g Symbios custom-made hip prosthesis). 

The Cup

The patients pelvic socket (acetabulum) is resurfaced using the cup. This is either fixed with cement or "uncemented" (fixed with bone on-growth). Sometimes, screws are also passed into the pelvic bone to help attach uncemented cups.


Whilst cemented cups are made from a single block of plastic, uncemented cups are formed from titanium and allow the insertion of metal, plastic, or ceramic liners. All cups are fundamentally the same shape (hemispherical) and typically vary in diameter from 48-56mm. My practice has moved exclusively to uncemented cups as this affords greater versatility during surgery and allows for potentially easier/ bone saving revision surgery if this is required. 

The Bearing

Movement occurs between the surface of the ball head and the shell liner ("the bearing"). The ball is made from either a metal or ceramic and the socket may be either plastic, metal or ceramic. During the early days of hip surgery, the polyethylene used in the cups would tend to wear-out after 10-15 years, necessitating revision surgery. Thankfully, modern hip replacement materials are far less susceptible to wear. 


The extraordinarily low levels of wear seen with ceramic on ceramic bearings make this combination attractive for very active patients. Recent refinements to the material properties of polyethylene (high cross-linking and vitamin E enrichment) are set to further improve the already excellent longevity of ceramic-on-poly' bearings.


Occasionally, when there is an increased risk of dislocation, a very large plastic head may be used (a "dual mobility" bearing).


METAL-ON-METAL BEARINGS ARE NOT USED IN ANY FORM WITHIN MR BARTLETTS PRACTICE.

How to prepare for hip surgery

taking you step by step through how to best prepare for total hip replacement surgery

Total Hip Replacement faq



The above is generalised advice; it is better to come to the office to talk directly to Mr Bartlett

Revision ("redo") Hip Replacement Surgery

A custom-made replacement socket was used to treat the loose cup and extensive pelvic bone loss

Why do some hip replacements need to be revised?

Whilst it is anticipated that revision hip replacement surgery will  be required less often required in the future, approximately 8,000 procedures are still performed in England and Wales each year. Broadly speaking, the risk of requiring a revision procedure within the first decade after surgery is one in twenty.

In the past, it was common for the replacement parts to simply "wear-out" or even break. Thankfully these problems are now rarely seen. Revision surgery may be required for the treatment of infection, dislocation, fracture or if the implant becomes loose. Sometimes surgery is needed to correct the treatment of hip fractures. More recently, some people suffering from allergic reactions to Cobalt and Chromium ions released from the now discontinued "metal-on-metal" hip replacements have also needed further surgery.

What is revision hip surgery?

Revision hip replacement surgery can vary greatly in complexity. The principal aims are to provide a dependable and anatomical reconstruction whilst preserving bone-stock and muscle function. Sometimes all that is required is a change of one component such as a worn liner or re-orientation of a component. Conversely, if there is a deep infection or significant bone loss in the femur or acetabulum (pelvic socket), reconstructive surgery can be extremely technically demanding. 

A trabecular metal augment was used to secure a new cup after loosening due to a pelvic fracture

What should I expect?

Surgery will take between about 1 hour for a simple procedure to up to four or five hours for a more complex reconstruction. Generally, the risks of complications (such as bleeding, infection, fracture & dislocation) are increased and recovery is slower compared to a "first-time" total hip replacement. This underlines the critical importance of careful patient preparation, surgical experience and meticulous planning.