You are in: eMedicine Specialties > Orthopedic Surgery > TRAUMA OsteoarthritisArticle Last Updated: Sep 12, 2008AUTHOR AND EDITOR INFORMATIONSection 1 of 13
  Author: Furqan H Siddiqui, MD, Director, Research Integrity Office, University of Louisville Hospital Furqan H Siddiqui is a member of the following medical societies: American Federation for Clinical Research Coauthor(s): James Monroe Laborde, MD, MS, Clinical Assistant Professor, Department of Orthopedics, Tulane Medical School; Adjunct Assistant Professor, Department of Biomedical Engineering, Tulane University; Adjunct Assistant Professor, Department of Physical Medicine and Rehabilitation, Louisiana State University Medical School; Consulting Staff, Department of Orthopedic Surgery, Louisiana State University Health Sciences Center Editors: Phillip J Marone, MD, Clinical Professor, Department of Orthopedic Surgery, Jefferson Medical College; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Samuel Agnew, MD, FACS, Associate Professor, Departments of Orthopedic Surgery and Surgery, Chief of Orthopedic Trauma, University of Florida at Jacksonville; Consulting Surgeon, Department of Orthopedic Surgery, McLeod Regional Medical Center; Dinesh Patel, MD, FACS, Associate Clinical Professor of Orthopedic Surgery, Harvard Medical School; Chief of Arthroscopic Surgery, Department of Orthopedic Surgery, Massachusetts General Hospital; Mary Ann E Keenan, MD, Professor, Vice Chair for Graduate Medical Education, Department of Orthopedic Surgery, University of Pennsylvania School of Medicine; Chief of Neuro-Orthopedics Program, Department of Orthopedic Surgery, Hospital of the University of Pennsylvania Author and Editor Disclosure Synonyms and related keywords: osteoarthritis, OA, degenerative joint disease, degenerative arthritis, osteoarthrosis, arthritis INTRODUCTIONSection 2 of 13
  Osteoarthritis (OA) is the most common joint disease and a major cause of morbidity and disability. It is commonly seen in the elderly population; however, its appearance at an early age is possible. Thus, the disease can no longer be considered a simple consequence of aging and cartilage degeneration. Unfortunately, in young patients, arthritis is often confused with traumatic arthritis, which occurs after an injury to a joint, whether by a macroincident or by repeated microincidents.1, 2, 3, 4 For excellent patient education resources, visit eMedicine's Arthritis Center. Also, see eMedicine's patient education article Osteoarthritis. ProblemComplications due to immobility, deconditioning, medication, and joint-related surgery can be fatal. OA is a major cause of disability in the United States, with approximately 68 million workdays lost and 4 million hospital admissions per year. FrequencyOsteoarthritis (OA) is the most common form of progressive joint disease worldwide, affecting 16 million (6%) American adults.5 Racial differences exist for both the prevalence and the pattern of joint involvement. Compared with whites, South African blacks and persons of Chinese, East Indian, or Native American descent have a lower prevalence of hip OA. Females have a higher prevalence of OA of the knees and hands, whereas males have a higher prevalence of OA of the hips. For knee OA, the female-to-male incidence ratio is 1.7:1. Age is the strongest determinant of OA; the prevalence of OA at all joint sites progressively increases with age. Estimates of the true prevalence of OA are imprecise because of the difficulties associated with the diagnosis. Estimates based on the radiographic evidence of knee OA are as follows: OA affects 25-30% of persons aged 45-64 years, 60% of persons older than 65 years, and more than 80% of persons older than 75 years.5 EtiologyThe daily stresses applied to the joints, especially the weight-bearing joints (eg, ankle, knee, hip), play an important role in causing osteoarthritis (OA). The hereditary component has long been recognized, particularly with generalized OA; a gene for OA has been identified and plays an important role. Potential risk factors include age, obesity, trauma, genetics, sex hormones, muscle weakness,6 and environment.7, 8 Old joints and osteoarthritic joints differ. With advancing age, cartilage volume, proteoglycan content, cartilage vascularization, and cartilage perfusion are reduced and may result in certain characteristic radiologic features that include joint-space narrowing and marginal osteophytes. However, biochemical and pathophysiologic findings support the notion that age alone is an insufficient cause of OA. Obesity increases the mechanical stress in a weight-bearing joint. It has been strongly linked to OA of the knees and, to a lesser extent, of the hips. Traumatic insults to the articular cartilage, ligaments, or menisci lead to abnormal biomechanics in the joints and enhance their premature degeneration. Menopause often increases the progression of OA; however, estrogen replacement therapy lowers the expected rate of radiographic and clinical findings in the knees and hips. Muscle dysfunction compromises the body's neuromuscular protective mechanisms, leading to increased joint motion, resulting in OA. This effect underscores the need for continued muscle toning exercises in all individuals to prevent muscle dysfunction. One should not confuse environmental factors as causes of OA, because these factors actually cause traumatic arthritis on a macrotraumatic or microtraumatic basis. This is especially true of individuals whose lifestyles require squatting, climbing stairs, or excessive kneeling. PathophysiologyThe pathology of osteoarthritis (OA) is the result of both the combined effect of tissue damage and an immune reaction to that damage. Changes resulting from repetitive microtrauma are usually seen in the load-bearing areas of the articular cartilage. OA usually begins with the swelling of the cartilage due to the increased synthesis of proteoglycans, which reflect an effort by the chondrocytes to repair the damage sustained. This stage may last for years or decades, and it is characterized by hypertrophic repair of the articular cartilage. As the disease progresses, the thickness of the joint surface is reduced. However, the level of proteoglycans is remarkably diminished, causing a loss of elasticity in the cartilage, which leads to its softening. As a result, loss of joint surface integrity occurs, and cartilaginous vertical clefts develop (fibrillation); deeper lesions expose the subchondral bone. Compression of the exposed trabecular bone can cause a fracture, and new bone formation (bony eburnation) can take place. The exposed bony surface can have necrotic lesions that lead to the formation of bone cysts. Simultaneously, angiogenesis of subchondral bone marrow as a result of the initial insult to the bone tissue causes calcification of the affected cartilage that stimulates endochondral ossification (osteophytes). In addition to the articular cartilage, the synovium, subchondral bone, ligaments, and neuromuscular apparatus may also show pathophysiologic changes. ClinicalPain is the most important symptom of osteoarthritis (OA). It begins early in the course of the disease, usually occurs after joint activity, is mild to moderate in intensity, and is relieved with rest. When pain occurs at rest, it is indicative of severe OA. Morning stiffness in OA is brief and localized, with the duration usually being less than 30 minutes, whereas the duration is much longer in inflammatory rheumatoid arthritis. Stiffness after a period of inactivity and gradual improvement after a short period of movement is known as the "gel phenomenon." Muscle activity in patients with OA is lessened because of pain and increased symptomatology, causing ambulatory episodes of giving way or buckling to occur. Excessive pain causes a loss of full joint extension and limited range of motion (ROM) during ambulation, leading to inevitable joint deformity and a loss of function. When an osteoarthritic knee or ankle joint is examined, bony enlargement due to proliferative change is often noted. Frequently, in affected osteoarthritic hands, Heberden nodes occur around the distal interphalangeal joints, and Bouchard nodes are seen at the proximal interphalangeal joints. Localized tenderness, especially in superficial joints, such as the knee or ankle, is often present, and a loss of motion and a crepitant feeling are detected. Secondary genu varum or valgum deformity may be present when patients ambulate. The tenderness experienced by osteoarthritic patients usually emanates from arthritis changes in the hip; this pain is difficult to mask and is accompanied by a hip flexion contracture. Not only is there loss of hip motion, but a loss of extension also occurs, as evidenced by the hip flexion contracture.When the spine is involved in OA, especially the lumbar spine, the associated changes are very commonly seen from L3 through L5. Symptoms include pain, stiffness, and occasional radicular pain from spinal stenosis. Spinal stenosis is caused by facet arthritic changes that result in compression of the nerve roots. The occurrence of an acquired spondylolisthesis is a common denominator of arthritis of the lumbar spine. INDICATIONSSection 3 of 13
Before any surgical procedure is considered, its risk-to-benefit ratio must be carefully evaluated, especially in young patients with OA that is secondary to trauma or sports-related injuries. Although no surgical procedure is absolutely indicated or contraindicated for osteoarthritis (OA), certain general aspects are important to consider—for instance, pain at rest that requires narcotics for control. Also, limitations in a patient's ability to climb stairs and to get into and out of an automobile may affect the patient's quality of life. Another important aspect in selecting a surgical procedure is its long-term functional outcome in patients. These factors must be integrated into an overall evaluation in selecting the appropriate surgical procedure. RELEVANT ANATOMYSection 4 of 13
See Treatment, Surgical therapy. CONTRAINDICATIONSSection 5 of 13
Patients with osteoarthritis (OA) must be evaluated for contraindications to surgery. Local and remote (eg, dental, urinary) infections must be ruled out or cured. Patients may need to be medically cleared for surgery by their primary care physician. The patient's vascular status may need to be evaluated. WORKUPSection 6 of 13
Lab Studies
Imaging Studies
Diagnostic Procedures
StagingOuterbridge classified articular cartilage damage based on the arthroscopic findings in patients affected with osteoarthritis (OA).7 The 4 grades are as follows:
TREATMENTSection 7 of 13
Medical therapyCurrently, the various treatments of osteoarthritis (OA) are aimed at controlling the symptoms of pain, including physical therapy to increase muscle tone and joint motion; medications; weight loss; avoidance of certain activities (eg, kneeling, squatting); and pharmacotherapy, including aspirin and nonsteroidal anti-inflammatory drugs (NSAIDs). Physical therapy Physical therapy has an important role in the management of OA. Exercise programs can be designed to achieve various goals, including muscle strengthening and improving ROM, flexibility, and aerobic conditioning. Modification of the patient's lifestyle is also important; measures may include weight reduction, restriction of vigorous activities, and use of supportive devices. Physical modalities may include the application of cold to affected areas to decrease pain during the acute inflammation phase, the use of superficial heat in the subacute phase, and the use of deep heat in the chronic phase of the disease. Nonpharmacologic modalities Nonpharmacologic modalities should be considered as initial management in the early stages of OA disease. Patients should be educated about OA, weight control, and avoiding activities such as kneeling and squatting that increase stress to weight-bearing joints. Physical modalities that can reduce OA pain include cold application in the acute phase, superficial-heat application in the subacute phase, and deep-heat application in the chronic phase. Range-of-motion (ROM) exercises and stretching may be helpful. Muscle strengthening, aerobic conditioning, and the use of gait aids (eg, cane, walker) and/or orthoses (eg, hand splint, knee brace) may be useful as well. Pharmacotherapy Nonpharmacologic strategies should be considered as adjuncts to pharmacologic measures. Pain relief can be achieved with low-to-moderate doses of simple analgesics and anti-inflammatory medications such as acetaminophen, aspirin, and NSAIDs. In a recent meta-analysis of trials comparing simple analgesics with NSAIDs in patients with knee OA, NSAID-treated patients had significantly greater improvement in both pain at rest and pain during motion. Other alternative or additional pharmacologic agents should be considered in patients in whom symptomatic relief is inadequate. The agent should be carefully selected after risk factors such as serious gastrointestinal and renal toxicity are evaluated. A topical analgesic cream (eg, methylsalicylate or capsaicin cream) is appropriate in cases of knee OA with mild to moderate pain, either as an adjunctive treatment or as monotherapy. Cyclooxygenase 2 (COX-2)–specific inhibitors, inhibitors such as celecoxib (Celebrex; Pfizer Inc, New York, NY) have been studied in patients with OA. COX-2 inhibitors have a more specific anti-inflammatory effect with fewer adverse effects. Celecoxib is more effective than placebo and has an efficacy comparable to that of naproxen in patients with hip or knee OA. Oral corticosteroids have no place in the management of OA. However, occasional intra-articular injections of corticosteroids may provide temporary benefit in flare-ups and in the relief of symptoms. Paracetamol (acetaminophen) is the drug of choice in the management of OA. Hyaluronic acid therapy consists of a series of injections, and it may exert its effect by providing physical cushioning or viscosupplementation of the joint. Oral glucosamine may have a role in the treatment of OA.13 NSAIDs and topical creams containing an NSAID or capsaicin may have a role as well. Surgical therapySurgery is indicated in those patients who have significant symptoms that have not responded to conservative therapy, whether it is treatment by oral or injected medications or the supportive role of physical therapy. The lower extremity surgical procedures include arthroscopy with debridement, valgus osteotomy for significant genu varum, or total knee arthroplasty. Fusion of a joint (eg, hip, knee, ankle) is rarely done today, but this procedure may be the only one that will work in a patient with infection following one of the other procedures. Arthroscopy Arthroscopy is a procedure of low invasiveness and morbidity and will not interfere with future surgery. This procedure is especially indicated for removal of meniscal tears and of any loose bodies that can occur. Less predictable arthroscopic procedures include debridement of loose articular cartilage with a microfracture technique, cartilaginous implants in areas of eburnated subchondral bone, or an arthroplasty such as the Genzyme procedure; these procedures have varying success rates and should only be used by those surgeons experienced with arthroscopic surgical techniques. In a study by Kirkley et al published in the New England Journal of Medicine in September 2008 ("A Randomized Trial of Arthroscopic Surgery for Osteoarthritis of the Knee"), it was found that "arthroscopic surgery for osteoarthritis of the knee provides no additional benefit to optimized physical and medical therapy."14 In an accompanying editorial, Marx stated, "However, osteoarthritis is not a contraindication to arthroscopic surgery, and arthroscopic surgery remains appropriate in patients with arthritis in specific situations in which osteoarthritis is not believed to be the primary cause of pain."15 Also see the Medscape article "Arthroscopic Surgery May Not Be Helpful for Knee Osteoarthritis."16 Osteotomy is used in active patients younger than 60 years who want to continue with reasonable physical activity. The principle underlying this procedure is to shift weight from the damaged cartilage on the medial aspect of the knee to the healthy lateral aspect of the knee. Osteotomy is most beneficial for significant genu varum or bowleg deformity. (Note: The osteotomy for genu valgum is not a procedure of high predictability regarding its effectiveness.) Osteotomy often can save individuals from having a total knee replacement until they are older. Contraindications for an osteotomy are knee flexion less than 90°, a flexion-extension contracture of more than 15°, and a significant amount of varus over 15°-20°. Instability due to previous trauma or surgery, severe arterial insufficiency, and bicompartmental involvement are also contraindications. Arthroplasty Arthroplasty (total joint replacement) is an excellent treatment in individuals with moderate to severe OA. This procedure is the most reliable, can significantly improve the patient's quality of life, and has results that last the longest. The rate of revision for arthroplasty has decreased with advances in the technique and prosthesis design. Candidates are preferably older than 60 years, so that they are less likely to need a repeat procedure. Arthroplasty consists of the surgical removal of joint surface and the insertion of a metal and plastic prosthesis. The prosthesis is held in place by cement or bone ingrowth into the porous coating. The use of cement relieves pain more quickly, but a porous coating may last longer; therefore, a porous coating is used in younger patients. Resection arthroplasty and fusion Older procedures that were used in major joints are now used in small joints and in large joints in which there is extensive bone destruction and/or persistent infection. Resection arthroplasty consists of the removal of the joint and allowing the scar to separate the bones and to help in reducing pain. This procedure is sometimes used after the failure of hip replacements if there is extensive bone destruction or persistent infection. Fusion consists of the union of bones on either side of the joint. This procedure relieves the pain but prevents motion and puts more stress on the surrounding joints. Fusion is sometimes used after knee replacements fail or as a primary procedure for ankle or foot arthritis. Preoperative detailsSee Contraindications. Intraoperative detailsSee Treatment, Surgical therapy, above. Postoperative detailsPostoperative care for the lower extremities may vary depending on the treatment used. Patients who undergo arthroscopy usually require a period of crutch use and/or exercise therapy; this typically lasts days or sometimes weeks. Those patients undergoing osteotomy and fusion require partial weight bearing until bony healing occurs; afterward, exercise is indicated. After joint replacement, patients require partial weight bearing, which progresses to full weight bearing in 1-3 months; ROM and strengthening exercises are started within a few days after joint-replacement surgery and continued until the patient has good ROM and strength. After resection arthroplasty of the hip, patients require instruction in the use of crutches or a walker, which is usually needed permanently. Follow-upPatients are monitored regularly until they have recovered from surgery. Afterward, they are examined at least yearly. COMPLICATIONSSection 8 of 13
Infection is the most feared postsurgical complication, especially in cases of total joint replacement. This complication is now rare, especially with the use of perioperative antibiotics. The prevention of thrombophlebitis and resultant pulmonary embolism is important in patients who undergo lower extremity arthroplasty procedures for osteoarthritis. The surgeon must use all of the material available to prevent these complications, especially initiating early motion and ambulation when possible. The use of low-molecular-weight heparin or warfarin is also indicated. OUTCOME AND PROGNOSISSection 9 of 13
Success rates with hip and knee arthroplasty are generally more than 90%. The longevity of the prosthetic implant depends upon the patient's activity. Younger and more active patients will require revisions, whereas the majority of older patients do not require revision. FUTURE AND CONTROVERSIESSection 10 of 13
Improvements in the prostheses designs and in surgical techniques should continue to increase success rates and decrease the rate and severity of complications. ACKNOWLEDGMENTSSection 11 of 13
The authors and editors of eMedicine gratefully acknowledge the contributions of previous coauthor Dr Siriporn Janchai to the development and writing of this article. MULTIMEDIASection 12 of 13
REFERENCESSection 13 of 13
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