Definitions for the ratings of the strength of recommendation (A-D) and the levels of evidence (Type I-Type V) are provided at the end of the "Major Recommendations" field.
Diagnosis
Osteoarthritis
Definition of the Problem
Osteoarthritis of the knee is an increasingly common problem due to a more active society, often leading to prior knee injuries, an increasingly elderly population, and a growing percentage of the population that is overweight. Osteoarthritis of the knee should be suspected when a patient presents with knee pain that has been longstanding, increases with activity, particularly weight bearing and stairs, and improves with rest. Onset of pain and dysfunction is often insidious. Deformity, fixed contracture, crepitance, and effusion are common findings. The differential diagnoses include inflammatory arthritis, bursitis or tendonitis, anterior knee pain, and internal derangement.
Patients entering Phase II of the guideline have failed to respond to conservative treatment. Pain, instability and function have not improved to a satisfactory level despite conservative treatment rendered, as outlined in Phase I of the guideline (see the National Guideline Clearinghouse (NGC) summary of the American Academy of Orthopaedic Surgeons [AAOS] guideline AAOS Clinical Guideline on Osteoarthritis of the Knee). This treatment may have included analgesics or nonsteroidal anti-inflammatory medications, activity modification including weight reduction, and therapeutic exercise. It may have included trial of durable medical equipment such as knee braces, ambulatory assistive devices, or orthoses. The patient may have undergone intra-articular injection in the knee with steroid or viscosupplementation.
Recommendations
For patients with osteoarthritis of the knee presenting to a musculoskeletal specialist, conservative treatment measures should have been exhausted. The age of the patient, level of symptomology, impact of knee dysfunction or pain on quality of life, and medical comorbidity should be assessed. If there is a medical contraindication to surgery, conservative treatment should be continued. The diagnosis of neuropathic arthropathy should be considered. The role for surgical intervention, including arthroplasty, is not well defined for a neuropathic joint ("D" Recommendation).
If a patient without a medical contraindication to surgery or neuropathic joint remains dissatisfied with the outcome of conservative care and has significant knee dysfunction, pain, or both, surgical alternatives should be considered. Evaluation by an orthopaedic surgeon is appropriate. Referral by a rheumatologist or physiatrist to an orthopaedic surgeon is indicated.
Previous Knee Infection or Osteomyelitis
For a patient with osteoarthritis that has failed to respond to conservative treatment and had a previous infection involving the knee, staged total knee replacement or knee fusion should be considered ("D" Recommendation). The choice to proceed with surgery, and between the two options, should be based on the patient's age, activity level, occupation, and a discussion. The discussion should include the natural history of the underlying condition including short- and long-term pain and physical impairment expectations with and without surgery. The efficacy of the proposed surgical procedure should be discussed. The risks and possible complications of each treatment option and reasonable expectation and timeframe to accomplish the expected outcome should be discussed.
Total joint replacement is contraindicated in the presence of active infection. When there is a history of infection, preoperative aspiration is often indicated. The risk of infection remains 10% or greater when total knee arthroplasty is performed even in the presence of infection in the distant past ("D" Recommendation). In a young patient with history of chronic infection, knee fusion should be considered ("D" Recommendation). Good results have been reported in total knee arthroplasty in patients under 55 years of age ("B" Recommendation).
Knee fusion may be considered in young, active, high demand patients with isolated bi- or tri-compartmental degenerative arthritis, particularly when associated with severe knee instability.
Patients Without Significant Joint Space Narrowing
Weight bearing standing anterior to posterior (AP) radiographs of the knee should be taken ("A" Recommendation). A lateral view of the knee joint and view tangential to the patellofemoral joint should be obtained. A standing radiograph, taken from posterior to anterior, with the knee flexed 45 degrees can show loss of cartilage in the posterior aspect of the knee ("A" Recommendation).
If there is suspicion of avascular necrosis (AVN) involving the knee, a magnetic resonance imaging (MRI) scan may be performed. If MRI confirms the presence of avascular necrosis in older patients, with extensive involvement of the condyle, total knee arthroplasty is often indicated ("B" Recommendation). Younger patients with more localized involvement may be candidates for a lesser procedure ("C" Recommendation).
If avascular necrosis is not present and there is not significant joint space narrowing, arthroscopic debridement can be considered. Arthroscopic debridement may be indicated for the treatment of patients with degenerative arthritis with mechanical symptoms ("B" Recommendation). Neither arthroscopic lavage nor debridement is indicated for patients without mechanical symptoms ("A" Recommendation). Results of arthroscopic debridement in patients with mechanical symptoms are variable, but high success rates are reported when there is not gross malalignment or instability, there is some articular cartilage remaining, and symptoms are well localized ("B" Recommendation).
Abrasion or drilling has not been shown to have added benefit ("C" Recommendation). Careful patient selection is required. "For the subgroup of knees with loose bodies or flaps of meniscus or cartilage that are causing mechanical symptoms, especially locking, catching, or giving way of the joint, there is a consensus that arthroscopic removal of these unstable tissues improves joint function and alleviates symptoms." (Felson DT, Buckwalter J; Editorial: Debridement and lavage for osteoarthritis of the knee, New Eng J Med, 347(2):132-3.)
If arthroscopic debridement for osteoarthritis of the knee is considered, a discussion with the patient should include the natural history of the underlying condition including short- and long-term pain and physical impairment expectations with and without surgery. The efficacy of the proposed surgical procedure should be discussed. The risks and possible complications of each treatment option and reasonable expectation and timeframe to accomplish the expected outcome should also be discussed.
Bi-compartmental or Tri-compartmental Arthritis
Patients with bi- or tri-compartmental arthritis of the knee who have failed to respond to conservative treatment should be considered for total knee arthroplasty ("A" Recommendation). The decision to proceed with total knee arthroplasty is shared by the patient and surgeon, and is based largely on quality of life issues. The choice to proceed with surgery should be based on the patient's age, activity level, occupation and a discussion. The discussion should include the natural history of the underlying condition including short- and long-term pain and physical impairment expectations with and without surgery. The efficacy of the proposed surgical procedure should be discussed. The risks and possible complications of each treatment option and reasonable expectation and timeframe to accomplish the expected outcome should be discussed.
Total joint replacement is contraindicated in the presence of active infection. Good results have been reported in total knee arthroplasty in patients under 55 years of age ("B" Recommendation).
Medial Compartment Arthritis
Young, active patients with varus alignment that have failed to respond to conservative treatment should be considered for tibial osteotomy ("A" Recommendation). Prerequisites for predictable results from proximal tibial osteotomy include: a range of motion of 5 to 90 degrees or greater, maintenance of some articular cartilage medially, minimal involvement of the lateral and patellofemoral compartments, and no more than minimal instability or lateral subluxation.
Patients who are less active may be considered for unicompartmental arthroplasty of the medial compartment of the knee ("B" Recommendation). Pain should be well localized to the medial compartment, and radiographs should demonstrate minimal involvement of the lateral and patellofemoral compartments. Reasonable weight and a functionally intact anterior cruciate ligament are associated with favorable outcome.
Patients with predominantly medial compartment arthritis who are not candidates for a tibial osteotomy or unicompartmental arthroplasty may be candidates for total knee arthroplasty ("A" Recommendation).
A discussion with the patient should include the natural history of the underlying condition including short- and long-term pain and physical impairment expectations with and without surgery. The efficacy of the proposed surgical procedure should be discussed. The risks and possible complications of each treatment option and reasonable expectation and timeframe to accomplish the expected outcome should also be discussed.
Lateral Compartment Arthritis
Young, very active patients with isolated narrowing of the lateral compartment may be candidates for a distal femoral varus osteotomy ("B" Recommendation). Distal femoral varus osteotomy is indicated when there is 10 degrees or more of tibiofemoral valgus, particularly when the joint line is oblique.
Patients who are not candidates for a distal femoral varus osteotomy may be candidates for total knee arthroplasty ("A" Recommendation) or, occasionally, unicompartmental arthroplasty of the lateral compartment ("C" Recommendation).
Isolated Patellofemoral Arthritis
Young, very active patients with symptoms and radiographic changes isolated to the patellofemoral joint may be considered for a procedure to elevate the tibial tubercle ("D" Recommendation) or a patellectomy ("D" Recommendation). The role of patellectomy is not well defined and indications are limited. Results of tibial tubercle elevation have been variable with a significant complication rate.
A patient who is not young or very active may be a candidate for total knee arthroplasty ("B" Recommendation). A patellofemoral arthroplasty may also be considered, but the role for this surgical procedure is not well defined and indications are limited ("B" Recommendation).
A discussion with the patient should include the natural history of the underlying condition including short- and long-term pain and physical impairment expectations with and without surgery. The efficacy of the proposed surgical procedure should be discussed. The risks and possible complications of each treatment option and reasonable expectation and timeframe to accomplish the expected outcome should also be discussed.
Alternative Approaches
Continued conservative care for osteoarthritis of the knee may result in continued pain, dysfunction, and limitation in function. This often results in a diminution in quality of life. The avoidance of the risk and discomfort of surgery, for some patients, is desirable. There is some evidence that a long delay before arthroplasty is performed may result in a slightly poorer outcome, possibly due to worsening of muscle function and joint motion ("C" Recommendation).
Definitions:
Strength of Recommendation
A. Type I evidence or consistent findings from multiple studies of types II, III, or IV
B. Types II, III, or IV evidence and findings are generally consistent
C. Types II, III, or IV evidence, but findings are inconsistent
D. Little or no systematic empirical evidence
Levels of Evidence
Type I. Meta-analysis of multiple, well-designed controlled studies; or high power randomized, controlled clinical trial
Type II. Well-designed experimental study; or low-power randomized, controlled clinical trial
Type III. Well-designed, non-experimental studies such as nonrandomized, controlled single-group, pre-post, cohort, time, or matched case-control series
Type IV. Well-designed, non-experimental studies, such as comparative and correlational descriptive and case studies
Type V. Case reports and clinical examples
Consensus/opinion (as it is used in bibliography of the original guideline): Articles representing expert consensus and not meeting the rigid I-V measurement are noted to represent consensus/opinion.
