Cruciate ligament integrity in osteoarthritis of the knee.

OBJECTIVE: To evaluate, using magnetic resonance imaging (MRI), the prevalence of anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) rupture in knees with symptomatic osteoarthritis (OA) compared with those without OA, and the relationship to pain and recalled injury. METHODS: MRI and plain radiography of the knee were performed in a group of 360 subjects with painful knee OA (cases; 66.7% male, mean age 67.1 years) and 73 without knee pain (controls; 57.5% male, mean age 66.1 years). MRIs were read for the presence or absence of complete or partial ACL or PCL tear. Subjects with knee pain were asked to quantify severity of pain on a visual analog scale and to report whether they could recall a significant knee injury (requiring use of a cane or crutches). We compared the prevalence of ACL and PCL rupture in those with and those without knee pain and also evaluated whether, in cases, there was any association with recalled knee injury. RESULTS: The proportion of cases who had complete ACL rupture was 22.8%, compared with 2.7% of controls (P = 0.0004). PCL rupture was rare both in cases (0.6%) and in controls (0%). Cases with ACL rupture had more severe radiologic OA (P < 0.0001) and were more likely to have medial joint space narrowing (P < 0.0001) than cases with intact ACLs, but did not have higher pain scores. Among cases, only 47.9% of those with complete ACL tears reported a previous knee injury, compared with 25.9% of those without complete ACL tears (P = 0.003). CONCLUSION: ACL rupture is more common among those with symptomatic knee OA compared with those without knee OA. Fewer than half of subjects with ACL rupture recall a knee injury, suggesting that this risk factor for knee OA is underrecognized.

Periarticular lesions detected on magnetic resonance imaging: prevalence in knees with and without symptoms.

OBJECTIVE: To evaluate, using magnetic resonance imaging (MRI), the prevalence of periarticular lesions in older persons with or without knee pain, and to assess the association of these lesions with knee pain. METHODS: Subjects ages 45 years and older, with or without knee pain, were recruited from Veterans Affairs medical centers and from the community. Weight-bearing posteroanterior, skyline, and lateral radiographs were obtained in all subjects. Subjects were divided into 3 groups: those with radiographic OA (ROA) and knee pain (n = 376), those with ROA and no knee pain (n = 51), and those with neither ROA nor knee pain (n = 24). A single knee (the more symptomatic one in subjects with knee pain) was imaged with a 1.5T scanner using T1- and T2-weighted and proton-density spin-echo imaging sequences. MRIs were read for the presence of periarticular lesions, which were categorized (according to their general location) as being either peripatellar (prepatellar, superficial infrapatellar, deep infrapatellar) or "other periarticular lesions" (semimembranosus-tibial collateral ligament bursitis, anserine bursitis, iliotibial band syndrome, tibiofibular cyst). RESULTS: Patients with knee pain had more severe radiographic disease than did subjects who were asymptomatic. Peripatellar lesions (prepatellar or superficial infrapatellar) were present in 12.1% of the patients with knee pain and ROA, in 20.5% of the patients with ROA and no knee pain, and in 0% of subjects with neither ROA nor knee pain (P = 0.116). However, other periarticular lesions were present in 14.9% of patients with both ROA and knee pain, in only 3.9% of patients with ROA but no knee pain, and in 0% of the group with no knee pain and no ROA (P = 0.004). CONCLUSION: Although peripatellar lesions are equally common among subjects with knee pain and those without knee pain, other periarticular lesions (including bursitis and iliotibial band syndrome) are significantly more common among subjects with knee pain and may contribute to pain in these individuals.

Bone marrow edema and its relation to progression of knee osteoarthritis.

BACKGROUND: While factors affecting the course of knee osteoarthritis are mostly unknown, lesions on bone scan and mechanical malalignment increase risk for radiographic deterioration. Bone marrow edema lesions on magnetic resonance imaging correspond to bone scan lesions. OBJECTIVE: To determine whether edema lesions in the subarticular bone in patients with knee osteoarthritis identify knees at high risk for radiographic progression and whether these lesions are associated with limb malalignment. DESIGN: Natural history study. SETTING: A Veterans Administration hospital in Boston, Massachusetts. PATIENTS: Persons 45 years of age and older with symptomatic knee osteoarthritis. MEASUREMENTS: Baseline assessments included magnetic resonance imaging of the knee and fluoroscopically positioned radiography. During follow-up at 15 and 30 months, patients underwent repeated radiography; at 15 months, long-limb films were obtained to assess mechanical alignment. Progression was defined as an increase over follow-up in medial or lateral joint space narrowing, based on a semi-quantitative grading. Generalized estimating equations were used to evaluate the relation of medial bone marrow edema lesions to medial progression and lateral lesions to lateral progression, before and after adjustment for limb alignment. RESULTS: Of 256 patients, 223 (87.1%) participated in at least one follow-up examination. Medial bone marrow lesions were seen mostly in patients with varus limbs, and lateral lesions were seen mostly in those with valgus limbs. Twenty-seven of 75 knees with medial lesions (36.0%) showed medial progression versus 12 of 148 knees without lesions (8.1%) (odds ratio for progression, 6.5 [95% CI, 3.0 to 14.0]). Approximately 69% of knees that progressed medially had medial lesions, and lateral lesions conferred a marked risk for lateral progression. These increased risks were attenuated by 37% to 53% after adjustment for limb alignment. CONCLUSION: Bone marrow edema is a potent risk factor for structural deterioration in knee osteoarthritis, and its relation to progression is explained in part by its association with limb alignment.

The clinical importance of meniscal tears demonstrated by magnetic resonance imaging in osteoarthritis of the knee.

BACKGROUND: Meniscal tears are frequently found during magnetic resonance imaging of osteoarthritic knees. However, the prevalence and clinical relevance of these tears have not been determined. This study was designed to investigate the relationship between meniscal tears and osteoarthritis and between such tears and pain in patients with osteoarthritis. METHODS: Magnetic resonance imaging and plain radiography of the knee were performed in a group of 154 patients with clinical symptoms of knee osteoarthritis and a group of forty-nine age-matched asymptomatic controls. Pain scores (according to a 100-mm visual analog scale) and functional scores (according to the Western Ontario and McMaster University Osteoarthritis Index [WOMAC]) were determined for ninety-one of the patients with symptomatic osteoarthritis. Meniscal tears were defined as tears extending to an articular surface as seen on magnetic resonance imaging. RESULTS: A medial or lateral meniscal tear was a very common finding in the asymptomatic subjects (prevalence, 76%) but was more common in the patients with symptomatic osteoarthritis (91%) (p < 0.005). In the group with symptomatic osteoarthritis, a higher Kellgren-Lawrence radiographic grade was correlated with a higher frequency of meniscal tears (r = 0.26, p < 0.001), and men had a higher prevalence of meniscal tears than did women (p < 0.01). However, there was no significant difference with regard to the pain or WOMAC score between the patients with and those without a medial or lateral meniscal tear in the osteoarthritic group (p = 0.8 to 0.9 for all comparisons). The power of the study was 80% to detect a difference in the WOMAC scores of 15 points and a difference in the scores on the visual analog scale of 16 mm. CONCLUSIONS: Meniscal tears are highly prevalent in both asymptomatic and clinically osteoarthritic knees of older individuals. However, osteoarthritic knees with a meniscal tear are not more painful than those without a tear, and the meniscal tears do not affect functional status. These data do not support the routine use of magnetic resonance imaging for the evaluation and management of meniscal tears in patients with osteoarthritis of the knee. LEVEL OF EVIDENCE: Diagnostic study, Level I-1 (testing of previously developed diagnostic criteria in series of consecutive patients [with universally applied reference "gold" standard]). See p. 2 for complete description of levels of evidence.