Common Causes of Hip Pain
Time or age-related wearing of the hip joint which results in lost cartilage and inflammation of the joint tissue. Without adequate cartilage, bones may grate against one another, making movement difficult and painful. Most common in people over the age of 50.
An auto-immune disorder. Inflammation-based damage to hip joints caused by an immune system “attack” on joint tissue. May affect both young and older adults.
Cartilage damage that occurs after the joint is damaged by a trauma-related fracture or serious injury such as car accident.
Damage to a hip joint caused by injury or disease, such as cancer, which restricts blood flow to the femoral head. Without an adequate blood supply, bone tissue will die or “necrose’ and collapse.
Childhood Hip Disease
Hip problems that occur in childhood may result in improper development or irregular formation. Even when treatment during childhood is considered successful, pain may develop during adulthood.
As the body ages, degradation of the hip joints may cause pain and loss of function. In some cases, hip pain may become severe and limit mobility. Though some people experience pain relief through non-surgical treatments such as medications and physical therapy, some patients will require surgery to correct the hip damage. Surgical hip replacement options may include hip resurfacing, partial hip replacement or total hip arthroplasty.
Hip Joint Damage and Hip Pain
The hip is one of the most complex joints in the body. It is constructed of a ball-and-socket joint which connects the trunk to the leg. The “ball” on the top of the large, leg bone or femur is known as the femoral head and fits into the “socket” on the pelvis and is also called the acetabulum. When healthy, the hip joint is lined with smooth, flexible cartilage and filled with synovial fluid which allows for smooth and continuous movement.
Over time, these tissues may become worn and damaged or degraded. In some cases, certain disease states may also cause premature wearing of the hip joint. When this occurs, movement may become difficult and result in significant hip pain.
Hip pain may be caused by damage from arthritis, inflammation, injuries or from simple wear and tear which occurs over a lifetime of use. The interior of the hip joint may become worn and rough, resulting in painful movement. In some cases, degradation may become severe enough that the femoral head and acetabulum bone surfaces grate against one another.
Hip pain may make movement difficult and in severe cases, may result in a loss of mobility and inability to walk. Non-surgical treatments may include physical therapy, medications, and movement aids but some patients will require surgical intervention to repair or replace the hip joint.
Osteoporosis Hip Replacement
Osteoporosis occurs when bone density is lost, leading to a weaker bone structure that can be “porous” in nature. Osteoporosis results in bones that are more likely to fracture or break, even when subjected to only mild trauma or stress. Certain factors increase the chance of getting osteoporosis including genetics, age, gender, diet, and lifestyle, along with some medical conditions and specific medications. Osteoporosis is often considered to be a factor in a hip fracture which may require a hip replacement.
- Nearly three-quarters of hip fracture patients are women. About 50% of all women in the U.S. and 25% of men will experience a fracture related to osteoporosis.
- Hip fracture is the most serious type of osteoporosis-related fracture and occurs in more than 300,000 Americans per year.
- Most people who experience a hip fracture will require assistance with daily activities and up to 20% of senior-aged hip fracture patients die in the first year following the event.
- Because the U.S. population is aging, the number of hip fractures that occur each year continues to rise.
- In women over 45, osteoporosis-related events are responsible for more hospital days than many “common” disorders such as diabetes, heart attack, and breast cancer.
Osteoporosis-related hip degeneration may be more difficult to treat with hip replacement due to loss of “healthy” bone to support the implant. Certain types of hip replacement devices may be more likely to produce early “failure” through post-surgical fracture or dislocation.
Types of Hip Replacement
Depending on the severity of joint damage or degradation, the severity of hip pain and loss of mobility and other patient factors, there are several options for hip repair surgery. Options include total joint replacement, partial joint replacement, and hip resurfacing.
Total Hip Replacement
Total hip replacement requires the removal of the entire hip joint, including a portion of the femur bone, to be replaced with an artificial joint. It may be done through a single, large incision or through a newer, less-invasive procedure which utilizes multiple, smaller incisions.
Once the top portion of the femur is removed, it will be replaced with a large stem topped with the “ball” which will slide inside a cup-shaped section attached to the pelvis. Implants may have components which include metal, ceramic, plastic or a combination and are attached with or without cement, depending upon the design and needs of the patient.
Surgeries performed in the traditional one-incision method may be quicker, requiring less surgery time but may take longer for post-surgical recovery. The less-invasive procedure may require a longer in-surgery time and may be reserved for younger patients who are not overweight and considered to be healthier.
Partial hip replacement
Partial hip arthroplasty is performed to remove and replace only one portion of the hip joint. In most cases, the “ball” section of the femur is removed and replaced with an artificial implant, composed of metal or ceramic. Partial hip replacements are more common in patients who do not have osteoporosis or significant bone degradation but have experienced a trauma of some type.
Hip resurfacing is a surgical procedure performed to smooth rough or worn joint surfaces. It often involves placement of a device known as an acetabular cup inside the hip joint and may require a metallic covering be added to the femoral head.
Hip resurfacing or partial hip replacement may sometimes be used to delay the need for a total joint replacement.
Hip implant types
Artificial hip joints are similar in design but may be composed of different materials and are attached or seated by slightly different methods which may or may not involve the use of cement. Hip implants generally fall into one of the following categories based on component materials including:
- Metal-on-polyethylene plastic
- Ceramic-on-polyethylene plastic
Each type of material has characteristics which are both advantageous and disadvantageous, however, the largest number of serious adverse events has occurred in the metal-on-metal hip replacement device category. Multiple recalls have been issued and thousands of lawsuits have been filed and settled for MoM type implants but many remain in State and Federal courts.
Complications of Hip Replacements
All surgical procedures carry a certain number of risks including adverse events associated with anesthesia, infection, pain and long recovery times. Hip replacement procedures also carry a number of specific risks of complications, some of which may be serious or even, life-threatening.
Hip replacement complications may include:
- Nerve damage
- Bone fracture
- Bone loss
- Joint stiffness
- Joint loosening
- Joint dislocation
- Allergic reaction to cement
- Body-wide inflammation
- Metal poisoning
Severe side effects or complications of hip replacement surgery may lead to pain, loss of mobility, hospitalization and extended illness due to device failure.
Metal-on-metal implants and Metallosis
Metal-on-metal hip implants were designed to be more durable and longer lasting than other hip implants. Their solid, all-metal construction was intended to reduce side effects caused by breakage and shearing but has resulted in a number of complications. The metallic surfaces are allowed to grate against one another and result in the shedding of metallic fragments which may produce localized inflammation and in severe cases, may result in death and dissolution of bone tissue, known as necrotic osteolysis.
In addition to a localized response which may lead to implant failure, metal implants composed of chromium or cobalt alloys may shed toxic metal ions which are absorbed into the bloodstream. Patients have experienced body-wide inflammation due to poisoning by these metal ions.
Many of the MoM devices were approved under a fast-track FDA process known as the 501(k) pathway which allows manufacturers to skip costly clinical testing by claiming that new products are similar to previously approved devices. Many of the all-metal hip joint implants had not ever been used in human patients before being offered for public sale. Even though some of these devices have since been recalled, many are still in use and have a higher-than-normal rate of failure, placing recipients at risk.
Hip Implant Revision Surgery
Some patients who experience complications after hip replacement will require a revision or repair surgery to remove a defective device, repair damage that may have occurred and potentially implant a new device. In some cases, repair and reconstruction may require multiple surgeries, damage may be severe and result in permanent disability.
Hip Implant Recalls
There are multiple hip implant devices available on the market and are manufactured by a number of companies. The most common hip replacement products come from manufacturers including
- Stryker Orthopaedics
- Zimmer Holdings and Biomet, acquired by Zimmer
- Dupuy Orthopaedics, subsidiary of Johnson & Johnson
- Smith and Nephew
- Wright Medical Technology
The Food and Drug Administration (FDA) has not issued a general recall for metal-on-metal devices, however multiple models have been recalled by their manufacturers. All of the largest manufacturers have recalled at least one hip implant device and in some cases, multiple products have been recalled and discontinued.
Hip Replacement Lawsuits
Manufacturers of faulty hip implant devices, particularly the metal-on-metal type, have faced thousands of lawsuits due to high failure rates and serious injuries caused by their use. Many of these lawsuits have been settled but many still remain in the court systems. As MoM devices are still currently in use, many patients may be at risk and more lawsuits are likely expected.
Patients who have been injured by hip implant devices may receive compensation for past and future medical costs, lost wages, pain, and suffering and in some cases, have received punitive damage awards. Each lawsuit is different and must be evaluated separately.
- Cleveland Clinic. (2017) Treatment and Procedures: Hip Revision. Cleveland Clinic. Accessed on 14 August 2017 2017
- FDA. (2013). Concerns about Metal-on-Metal Hip Implants. US Food and Drug Administration, Accessed 14 August 2017 2013
- FDA. (02 July 2014) Recalls Specific to Metal-on-Metal Hip Implants. US Food and Drug Administration, Accessed 14 August 2017
- FDA. (10 February 2011). Hip Implant Systems. Accessed 14 August 2017 10 February 2011
- Fabi, D., et al. (2012). Metal-on-Metal Total Hip Arthroplasty: Causes and High Incidence of Early Failure. Accessed 14 August 2017 2012
- Gallagher, J. (12 March 2012). Metal-on-metal hip replacements ‘high failure rate’. BBC News. Accessed on 14 August 2017 12 March 2012
- Ortho Info. (02 December 2011). Modern Metal-on-Metal Hip Implants: A Technology Overview. American Academy of Orthopaedic Surgeons, Accessed 14 August 2017 02 December 2011