The hip is a ball-and-socket joint that bears the weight of the body and allows an excellent range of movement. There are many causes of hip pain, which include:
- Wear and tear — osteoarthritis
- Loss of blood supply, resulting in degenerative change — avascular necrosis
- Trauma — hip fracture from a fall, typically in older patients
- Soft tissue disorders — labral tear, trochanteric bursitis
- Inflammatory cause — rheumatoid arthritis
- Referred pain from the spine
The young adult with hip pain
Young adults tend to be more active and involved in sports, which can result in soft tissue and cartilage injury. Pain at the side of the hip may be due to trochanteric bursitis, or snapping hip syndrome. Pain behind the hip, in the buttock region, may be referred from the spine. Pain at the front of the hip, in the groin region, may be related to the hip joint itself. An underlying condition such as femoro-acetabular impingement may be present, where subtle abnormalities in the shape of the hip may cause pain through certain ranges of motion. Labral tears may also be a cause of hip pain in an athlete. The labrum is a cartilaginous ring surrounding the acetabulum (socket of the hip joint) that increases hip joint stability.
An athlete with hip pain should seek specialist help early to avoid further injury. At the consultation, a careful history (set of questions) should be taken, and examination performed to obtain a diagnosis. This may be confirmed through imaging techniques such as X-rays, MRI, or an MR Arthrogram, where dye is injected into the joint. Sometimes, a specialist may arrange a steroid injection to the hip as a diagnostic procedure. Most conditions will respond to painkillers and physiotherapy. Those that do not improve may be suitable for arthroscopic (keyhole) surgery.
The older patient with hip pain
Senior patients with hip pain may also experience stiffness, and decreased ability to climb stairs and walk long distances. Primary hip osteoarthritis (wear and tear) is much less common in Asia than in the West. Patients who have severe degenerative change in the hips may have had a problem since childhood (developmental dysplasia), loss of blood supply to the femoral head (avascular necrosis), or even a previous injury to the hip joint (post-traumatic osteoarthritis).
When surgery is required
Non-surgical management of hip pain is usually recommended first. This includes lifestyle changes, physiotherapy, medication and the use of walking aids. If severe pain persists, and is associated with severe degenerative change on X-ray, then the patient may be suitable for a hip replacement.
Total hip replacement and robotic surgery
The main aim of hip replacement surgery is to relieve pain and improve quality of life. This involves removing the worn-out joint and replacing it with an implant. The type of material used in the implant is dependent on factors such as the patient’s age and bone quality. The good news is that this operation has an excellent satisfaction rate: up to 95% of patients experience pain relief. Records from Joint Registries worldwide, which track revision of hip replacements, show that certain types of hip implant have an excellent survival rate of beyond 10 years following surgery.
In the past, surgeons used plastic templates and X-rays to estimate what size of implant to use and where to position it. With the development of robotic systems such as Makoplasty, the surgeon can now plan and perform an operation with accuracy to within a millimetre. Certain patients who have broken their hip but are relatively young and have good hip function prior to their injury may also be suitable for total hip replacement.
Undergoing hip surgery
It is important for the patient to understand the risks and benefits of total hip replacement, and these should be carefully explained prior to surgery. One of the pre-operative steps involves assessing and optimising any pre-existing medical conditions. Pre-operatively, a patient should also see a physiotherapist to learn particular exercises and how to walk with an aid.
Ideally, the patient can stand and walk right after surgery with walking aids, and aim to be discharged from hospital within three days. Physiotherapy is an important part of the recovery process. Usually, the patient can drive, return to work, and discard walking aids between six- and 12-weeks following surgery.
Hip replacement surgery is intended to relieve pain, not a licence to return to all activities or forms of sport. Younger patients undergoing hip replacement have higher revision rates over time, perhaps because they have more active lifestyles than older patients. In summary, total hip replacement is an excellent solution for hip pain in the carefully selected and prepared patient.