Hip Pain
Hip pain is a type of pain relevant to many people in the United States today. It may be commonly perceived as an issue that affects older people, but can in reality affect individuals of many age groups. The hip is a joint (or articulating junction) where the pelvic bone and the thighbone (the femur) meet. Many forms of hip pain are localized to the joint itself. However, some conditions associated with hip pain may also result in pain that radiates further down the leg. Hip pain may have an onset or intensify in response to normal activities such as walking. It may progress to a point at which such activities are significantly impaired or otherwise affected.
Causes Of Hip Pain
Many cases of hip pain are associated with damage to joints that is progressive, or increases over time.
Osteoarthritis is another condition associated with advancing age that may be a source of hip pain. This disorder affects approximately one in ten people in the developed world. It is an autoimmune disease, in which components of the immune system target tissues within joints as if they were foreign or infective particles, leading to inflammation in the joint. Inflammation is associated with pain, and may be chronic in nature. This condition is not related to bone loss. However, it is a prominent cause of hip replacements.
Hip pain in adults and teenagers may be related to femoroacetabular impingement (or FAI). This condition results in excessive friction between the bony surfaces of the joint, resulting in pain and increased disability. This condition is often seen in younger people who engage in extensive sporting or athletic activities. FAI is often a consequence of the greatly increased movement of the hip while doing so. This may be sustained in the course of high-volume running and other similar activities while training or playing sports.
The labrum is a band of cartilage located around the two main bones of the joint. A labral tear can result in chronic pain that persists long-term. Factors that affect the duration of the pain include misdiagnosis. Labral tears may be mistaken for other sources of hip pain, including muscular damage or conditions that affect the bones of the joint. Impingements and labral tears may be corrected with surgery. The labrum can be reconstituted or replaced with a graft from the patient’s other tissues.
The hip joint, along with the pelvis and lower back, may be adversely affected by the regular use of shoes that impose additional stress and forces on these bones. A prominent example of this is footwear with high heels.
There are many other risk factors associated with hip pain. The sacroiliac joint connects part of the spine with the pelvis, and contains nerves that are responsible for parts of the body below this point. Therefore, damage to the sacroiliac joint may be felt as pain in the vicinity of the hip joint. Inadvertent injury to nervous tissue sustained in the course of surgery on the lower back may have a similar effect.
Hip Pain Diagnosis
The detection of the precise causative factor in a case of hip pain may be a difficult and complicated procedure. A pain specialist or physician will initiate a diagnosis by interviewing the patient. This may include questions about the region of the hip (or hips) in which pain is experienced, the duration of the pain, its severity, and whether the pain is constant or fluctuating.
Visualizing the joint using imaging technology such as ultrasound or magnetic resonance imaging (MRI) can help with a diagnosis. These techniques may enhance the detection of adverse events such as fractures or FAI. Computerized tomography (CT) is another imaging method also used in the diagnosis of hip pain. However, some research indicates that MRI is more effective than CT in this. The physician or specialist may also ask questions concerning the possibility of the presence of one or more risk factors, such as those outlined above.
The doctor may also physically examine the patient, which may contribute to diagnosis particularly when an injury sustained during training or sporting activities is suspected. A skilled physician can detect conditions, such as labral tears, that go undiagnosed by imaging techniques. X-ray techniques are also still employed in diagnosis, but are often substituted for other methods in response to concerns about radiation exposure.
Treatments For Hip Pain
Drug Therapy
Conventional pharmacological agents to reduce pain, or analgesics, are commonly indicated after a diagnosis of hip pain. Drugs recommended to treat hip pain may include many widely-available prescription and non-prescription drugs. One may be chosen based on the severity of the pain. Non-steroidal anti-inflammatory drugs (NSAIDS) are often indicated for some forms of hip pain. These drugs are associated with the effective inhibition of inflammation in joints and other tissues. They are commonly indicated in cases of hip pain associated with sports-related activity or injuries. NSAIDs are associated with side effects, including the increased risk of gastric ulcers, acid reflux, and kidney damage.
If these medications fail to generate the expected treatment effect, a physician and patient may consider more powerful painkillers. These molecules bind to the major pain receptors in the body and prevent them from propagating their signals to the brain.
Prevention of Hip Pain
The probability of hip pain can be controlled through prevention. This involves the reduction of exposure to the environmental or occupational risk factors that cause hip pain. For example, people involved in high-volume training may avoid hip pain by avoiding the over-exertion of the joint or its damage through poor techniques. These include aberrant running or gait styles. The analysis of these may reveal areas of technique or habit that pose an increased danger to the hip joint. This can also indicate where improvements in gait, that conserve the hip region, can be made.
Hip damage may also be associated with cartilage, ligament, or muscle strain or tearing. This can be avoided through adequate warming-up, stretches, and cooling-down. Pain may also be prevented by reducing the amount of potentially harmful behaviors done during training. These include running down inclines, which is associated with an increased risk of hip joint damage. The probability of hip pain may also be managed by adhering to training programs that include measures to avoid injury or wear-and-tear on the joint.
While exercise when not carried out properly may contribute to hip pain, exercise can also play a role in the prevention of hip pain. The maintenance of a moderate regimen of flexibility and resistance training is recommended for those who wish to reduce the risks of hip pain. This may be linked to observations of the beneficial effects of regular activity on the retention of muscle mass and bone density in seniors. Age-related muscle deterioration is associated with osteoarthritis and an increased risk of fractures related to osteoporosis. The retention of the tissues, including muscles, around the hip may promote the stability of the joint, and thus possibly reduce the risk of pain. In addition, the regeneration of bone is associated with stimulation caused by the movement of the tissues around it.
Other Methods Of Hip Pain Management
Some alternative treatments and interventions that address hip pain are currently proposed in scientific literature or are in development. Many of these are variations and new approaches to hip replacement. One of these is a minimal incision replacement procedure (also known as arthroplasty). These are distinct from standard arthroplasties in terms of the position and numbers of incisions made to place an implant.
Minimal incision arthroplasty is associated with reduced blood loss and recovery times compared to standard procedures. However, pain severity or duration as a result of minimal-incision surgeries is similar to that following standard arthroplasty. Another alternative to standard arthroplasty is reconstruction of the femoral head, in which missing bone tissue is replaced with acrylic cement. This approach has not resulted in appreciable differences in pain intensity.
Many cases of hip pain are related to synovial fluid loss, and thus increased contact between the bones of the joint. This is associated with conditions such as FAI and arthritis. Synovial fluid replacement (or viscosupplementation) may be performed using sterile biomaterials such as hyaluronic acid. This may have potential in pain reduction, and is currently under evaluation as a treatment option in cases of osteoarthritis. Viscosupplementation of the hip joint requires more testing or development before approval as a treatment option.
Another alternative treatment similar to arthoplasty is arthroscopy, in which damage to a joint is surgically visualized and sometimes also corrected. This is associated with significant improvements in functional status and pain scores for patients who underwent hip arthroscopy, according to some research. This technique has experienced a considerable amount of development since its introduction.
Arthroscopy is completed using an endoscope, to reduce invasion and damage to tissues. A surgeon may prefer to operate while the patient lies on his or her back or on their side with the hip to be evaluated uppermost. Arthroscopy can be completed using nerve blocks, (as described above) a similar injection into the femoral nerve, or a general anesthetic. The surgeon may have to dissociate the joint slightly using traction. This allows access to and visualization of the interior of the hip. This is enhanced using imaging techniques such as fluoroscopy.
Arthroscopy is often applied to disorders such as labral tears or FAI. In cases where impingements are detected, the excess bone formed on the femoral head or acetabulum is shaved off using small drill-like equipment. The labrum may be replaced using grafts, as above, or alternatively repaired. Arthroscopy may also be used in the correction of hip abnormalities in infants, thus avoiding a more chronic pain condition for these patients in the future.
These procedures are gaining support as a treatment linked to favorable outcome profiles. Arthroscopy may result in positive effects on the duration and intensity of pain in recovery. Research has demonstrated that patients treated for injuries and damage incurred while training, using arthroscopy, experience a significant decrease in the time taken to regain their form, compared to conventional procedures.
Arthroscopy is associated with some adverse events and side effects, however. These are mainly related to general anesthetics, if used. The after-effects of this may include respiratory depression, nausea, and difficulty in passing urine. If nerve blocks are used as alternative anesthesia, this may result in the adverse effects described earlier. Other complications include the development of infection in the hip or the incisions made. Some estimates suggest that this occurs in about 1% of all cases. Some cases of nerve damage, sustained in the course of traction or as a result of surgeon error, have also been reported. This can be associated with new-onset pain, which may become chronic. The rate of all complications in cases of hip arthroscopy is approximately 6%. However, arthroscopy has been shown to be effective in many cases, and may have potential in the treatment of hip pain associated with other sources, such as implant failure following arthroplasty.
Another potential target in pain management research is nerve growth factor (NGF). This protein controls the differentiation of stem cells into nerve cells. It also contributes to the regulation of pain signals as they are conducted from cell to cell. Clinical trials of new compounds that antagonize these actions have demonstrated potential in cases of hip pain. These studies have compared these NGF blockers to NSAIDs, and found the new drugs were superior in effect. However, they have also found that anti-NGF formulations may be associated with an increase in symptom severity in patients with osteoarthritis when taken with NSAIDs. This interaction has resulted in the need for hip replacement in some cases. Therefore, NGF blockers may be used as an alternative for older drugs, pending full clinical development and approval. These drugs are associated with their own panel of side effects, including sensory abnormalities, however.
Glucosamine has also been investigated as another alternative treatment for hip pain and damage. This molecule is a variation on a natural amino acid and is associated with some benefits in cases of arthritis. It is also a component of cartilage. Glucosamine is currently available as a supplement linked to positive effects on joint movement and function in some markets. However, glucosamine was not associated with significant differences in the progression or severity of arthritis-related pain when investigated in clinical studies. Other research found this molecule was not associated with positive effects on joint function or movement. Therefore, glucosamine may not gain approval as an alternative therapy in the management of hip pain.
Conclusion
Hip pain may be a significant source of disability and debility. It may be associated with many conditions and risk factors. These include osteoarthritis, occupational hazards, various forms of tissue damage, and genetic disorders. Hip pain is popularly linked to more senior age groups, but may also affect younger people. This type of pain may be acute or persistent.
There are many treatment options for pain emanating from the hip region. These include conventional painkillers and nerve blocks. Disrupting the pain-signaling parts of spinal nerves using radiofrequency ablation is another therapy associated with effective relief of moderate duration. Spinal cord stimulation is another option that involves the implantation of a semi-permanent nerve-modulating device to inhibit pain signaling. Alternative forms of treatment include transcutaneous electrical stimulation. Hip replacement, or arthroscopy, is an option for patients in severe chronic pain related to osteoarthritis or osteoporosis.
Physical therapy is another important component of therapy for many patients who require an optimal return to normal performance or everyday activity following hip surgery or trauma. Emerging treatments with promising application to cases of hip pain include arthroscopy and NGF-blocking drugs. Education and training in the prevention of hip damage may also contribute to reductions in the risk of this type of pain in the future.
