Martin Englund

Prevalence of Tibiofemoral Osteoarthritis 15 Years After Nonoperative Treatment of Anterior Cruciate Ligament Injury: A Prospective Cohort Study

Background The occurrence of osteoarthritis (OA), associated meniscal injuries, meniscectomy, and patient-related measures for patients treated nonoperatively after anterior cruciate ligament (ACL) injuries have not been well described in the literature in terms of natural history. Hypothesis Patients with ACL injury can achieve a low occurrence of tibiofemoral OA and good knee function when treated without ACL reconstruction. Study Design Cohort study (prognosis); Level of evidence, 2. Methods One hundred consecutive patients with an acute, complete ACL injury were observed for 15 years. All patients were primarily treated with activity modification and without ACL reconstruction. To achieve improved functional stability, supervised physical therapy was initiated early after injury. The patients were examined using anteroposterior weightbearing radiography. The Knee injury and Osteoarthritis Outcome Score (KOOS) was used to quantify knee-related symptoms and knee function. Results Seventy-nine patients consented to radiographic examination and 93 completed the KOOS questionnaire. Thirteen patients (16%), all of whom were among the 35 patients whose knees were meniscectomized, developed radiographic tibiofemoral OA. In contrast, none of the remaining nonmeniscectomized and radiographed knees developed OA (n = 44) (P < .0001). Sixty-three patients (68%) had an asymptomatic knee. Twenty-two patients (23%) had undergone ACL reconstruction with a mean time of 4 years after injury. Conclusion The study had a favorable long-term outcome regarding incidence of radiographic knee OA, knee function and symptoms, and need for ACL reconstruction. Although risk factors for posttraumatic OA are multifactorial, the primary risk factor that stood out in this study was if a meniscectomy had been performed. Early activity modification and neuromuscular knee rehabilitation might also have been related to the low prevalence of radiographic knee OA. In patients with ACL injury willing to moderate activity level to avoid reinjury, initial treatment without ACL reconstruction should be considered.

Prevalence of abnormalities in knees detected by MRI in adults without knee osteoarthritis: population based observational study (Framingham Osteoarthritis Study)

Objective To examine use of magnetic resonance imaging (MRI) of knees with no radiographic evidence of osteoarthritis to determine the prevalence of structural lesions associated with osteoarthritis and their relation to age, sex, and obesity. Design Population based observational study. Setting Community cohort in Framingham, MA, United States (Framingham osteoarthritis study). Participants 710 people aged >50 who had no radiographic evidence of knee osteoarthritis (Kellgren-Lawrence grade 0) and who underwent MRI of the knee. Main outcome measures Prevalence of MRI findings that are suggestive of knee osteoarthritis (osteophytes, cartilage damage, bone marrow lesions, subchondral cysts, meniscal lesions, synovitis, attrition, and ligamentous lesions) in all participants and after stratification by age, sex, body mass index (BMI), and the presence or absence of knee pain. Pain was assessed by three different questions and also by WOMAC questionnaire. Results Of the 710 participants, 393 (55%) were women, 660 (93%) were white, and 206 (29%) had knee pain in the past month. The mean age was 62.3 years and mean BMI was 27.9. Prevalence of “any abnormality” was 89% (631/710) overall. Osteophytes were the most common abnormality among all participants (74%, 524/710), followed by cartilage damage (69%, 492/710) and bone marrow lesions (52%, 371/710). The higher the age, the higher the prevalence of all types of abnormalities detectable by MRI. There were no significant differences in the prevalence of any of the features between BMI groups. The prevalence of at least one type of pathology (“any abnormality”) was high in both painful (90-97%, depending on pain definition) and painless (86-88%) knees. Conclusions MRI shows lesions in the tibiofemoral joint in most middle aged and elderly people in whom knee radiographs do not show any features of osteoarthritis, regardless of pain.

Prevalence, incidence and progression of hand osteoarthritis in the general population: the Framingham Osteoarthritis Study

Objectives To describe the prevalence and longitudinal course of radiographic, erosive and symptomatic hand osteoarthritis (HOA) in the general population. Methods Framingham osteoarthritis (OA) study participants obtained bilateral hand radiographs at baseline and 9-year follow-up. The authors defined radiographic HOA at joint level as Kellgren–Lawrence grade (KLG)≥2, erosive HOA as KLG≥2 plus erosion and symptomatic HOA as KLG≥2 plus pain/aching/stiffness. Presence of HOA at individual level was defined as ≥1 affected joint. The prevalence was age-standardised (US 2000 Population 40–84 years). Results Mean (SD) baseline age was 58.9 (9.9) years (56.5% women). The age-standardised prevalence of HOA was only modestly higher in women (44.2%) than men (37.7%), whereas the age-standardised prevalence of erosive and symptomatic OA was much higher in women (9.9% vs 3.3%, and 15.9% vs 8.2%). The crude incidence of HOA over 9-year follow-up was similar in women (34.6%) and men (33.7%), whereas the majority of those women (96.4%) and men (91.4%) with HOA at baseline showed progression during follow-up. Incident metacarpophalangeal and wrist OA were rare, but occurred more frequently and from an earlier age in men than women. Development of erosive disease occurred mainly in those with non-erosive HOA at baseline (as opposed to those without HOA), and was more frequent in women (17.3%) than men (9.6%). Conclusions The usual female predominance of prevalent and incident HOA was less clear for radiographic HOA than for symptomatic and erosive HOA. With an ageing population, the impact of HOA will further increase.

Population-based estimates of common comorbidities and cardiovascular disease in ankylosing spondylitis.

To study the rate of common comorbidities and cardiovascular disease in patients with ankylosing spondylitis (AS) compared with the general population seeking health care.

Tibiofemoral Joint Osteoarthritis: Risk Factors for MR-depicted Fast Cartilage Loss over a 30-month Period in the Multicenter Osteoarthritis Study

PURPOSE To assess baseline factors that may predict fast tibiofemoral cartilage loss over a 30-month period. MATERIALS AND METHODS The Multicenter Osteoarthritis (MOST) study is a longitudinal study of individuals who have or who are at high risk for knee osteoarthritis. The HIPAA-compliant protocol was approved by the institutional review boards of all participating centers, and written informed consent was obtained from all participants. Magnetic resonance (MR) images were read according to the Whole-Organ Magnetic Resonance Imaging Score (WORMS) system. Only knees with minimal baseline cartilage damage (WORMS < or = 2.5) were included. Fast cartilage loss was defined as a WORMS of at least 5 (large full-thickness loss, less than 75% of the subregion) in any subregion at 30-month follow-up. The relationships of age, sex, body mass index (BMI), ethnicity, knee alignment, and several MR features (eg, bone marrow lesions, meniscal damage and extrusion, and synovitis or effusion) to the risk of fast cartilage loss were assessed by using a multivariable logistic regression model. RESULTS Of 347 knees, 90 (25.9%) exhibited cartilage loss, and only 20 (5.8%) showed fast cartilage loss. Strong predictors of fast cartilage loss were high BMI (adjusted odds ratio [OR], 1.11; 95% confidence interval [CI]: 1.01, 1.23), the presence of meniscal tears (adjusted OR, 3.19; 95% CI: 1.13, 9.03), meniscal extrusion (adjusted OR, 3.62; 95% CI: 1.34, 9.82), synovitis or effusion (adjusted OR, 3.36; 95% CI: 0.91, 12.4), and any high-grade MR-depicted feature (adjusted OR, 8.99; 95% CI: 3.23, 25.1). CONCLUSION In participants with minimal baseline cartilage damage, the presence of high BMI, meniscal damage, synovitis or effusion, or any severe baseline MR-depicted lesions was strongly associated with an increased risk of fast cartilage loss. Patients with these risk factors may be ideal subjects for preventative or treatment trials.

Valgus malalignment is a risk factor for lateral knee osteoarthritis incidence and progression: Findings from the multicenter osteoarthritis study and the osteoarthritis initiative

OBJECTIVE To study the effect of valgus malalignment on knee osteoarthritis (OA) incidence and progression. METHODS We measured the mechanical axis from long limb radiographs from the Multicenter Osteoarthritis Study (MOST) and the Osteoarthritis Initiative (OAI) to define limbs with valgus malalignment (mechanical axis of ≥1.1° valgus) and examined the effect of valgus alignment versus neutral alignment (neither varus nor valgus) on OA structural outcomes. Posteroanterior radiographs and knee magnetic resonance (MR) images were obtained at the time of the long limb radiograph and at followup examinations. Lateral progression was defined as an increase in joint space narrowing (on a semiquantitative scale) in knees with OA, and incidence was defined as new lateral narrowing in knees without radiographic OA. We defined lateral cartilage damage and progressive meniscal damage as increases in cartilage or meniscus scores at followup on the Whole-Organ Magnetic Resonance Imaging Score scale (for the MOST) or the Boston Leeds Osteoarthritis Knee Score scale (for the OAI). We used logistic regression with adjustment for age, sex, body mass index, and Kellgren/Lawrence grade, as well as generalized estimating equations, to evaluate the effect of valgus alignment versus neutral alignment on disease outcomes. We calculated odds ratios (ORs) and 95% confidence intervals (95% CIs). RESULTS We studied 5,053 knees (881 valgus) of subjects in the MOST cohort and 5,953 knees (1,358 valgus) of subjects in the OAI cohort. In both studies, all strata of valgus malalignment, including 1.1° to 3° valgus, were associated with an increased risk of lateral disease progression. In knees without radiographic OA, valgus alignment >3° was associated with incidence (e.g., in the MOST, adjusted OR 2.5 [95% CI 1.0-5.9]). Valgus alignment >3° was also associated with cartilage damage on MR imaging in knees without OA (e.g., in the OAI, adjusted OR 5.9 [95% CI 1.1-30.3]).We found a strong relationship of valgus malalignment with progressive lateral meniscal damage. CONCLUSION Valgus malalignment increases the risk of knee OA radiographic progression and incidence as well as the risk of lateral cartilage damage. It may cause these effects, in part, by increasing the risk of meniscal damage.

The role of biomechanics in the initiation and progression of OA of the knee

The knee is one of the most common joints affected by osteoarthritis (OA), frequently with clinical presentation by middle age or even earlier. Accumulating evidence supports that knee OA progression is often driven by biomechanical forces, and the pathological response of tissues to such forces leads to structural joint deterioration, knee symptoms and reduced function. Well-known biomechanical risk factors for progression include joint malalignment and meniscal tear. The high risk of OA after knee injury demonstrates the critical role of biomechanical factors also in incident disease in susceptible individuals. However, our knowledge of the contributing biomechanical mechanisms in the development of early disease and their order of significance is limited. Part of the problem is our current lack of understanding of early-stage OA, when it starts and how to define it.

Prevalence and incidence of rheumatoid arthritis in southern Sweden 2008 and their relation to prescribed biologics

OBJECTIVES To gain updated estimates of prevalence and incidence of RA and proportion on biological treatment in southern Sweden. METHODS Inpatient and outpatient health care provided to residents in the southernmost county of Sweden (1.2 million inhabitants) is registered in the Skåne Health Care Register (SHCR). We identified residents aged > or = 20 years who had received a diagnosis of RA at least twice during 2003-08. Valid point prevalence estimates by 31 December 2008 were obtained by linkage to the Swedish population register, and information on biological treatment was obtained from the South Swedish Arthritis Treatment Group register. We also tested our estimates of RA occurrence in a series of sensitivity analyses to investigate the effect of altered case criteria and the uncertainty generated by clinical visits without diagnoses. RESULTS The prevalence of RA in adults was estimated to 0.66% (women = 0.94%, men = 0.37%). The prevalence peaked at age 70-79 years (women = 2.1%, men = 1.1%) before dropping in those aged > or = 80 years. Of prevalent cases, 20% had ongoing biological treatment, a percentage that was highest in women aged 40-49 years (36%). The incidence of RA in 2008 was estimated as 50/100,000 (women = 68/100,000, men = 32/100,000). CONCLUSIONS When compared with a previous report from southern Sweden, the prevalence of RA seems not to have declined in the last decade. The proportion of patients with ongoing biological treatment was slightly higher in women than men. SHCR data are promising additions to other methods to gain frequency estimates of clinically important disease in a timely and cost-efficient manner.

Knee buckling : Prevalence, risk factors, and associated limitations in function

Context Knee buckling is the sudden loss of postural support across the knee at a time of weight bearing. Its prevalence and consequences are not clear. Contribution This study of 2351 community-dwelling, middle-age and older adults found that 278 participants (12%) reported at least 1 episode of knee buckling in the past 3 months. Of these, 13% fell during the episode. Knee pain, quadriceps weakness, and worse physical function were associated with buckling. Caution The studys cross-sectional design limits causal inferences. Implications Knee buckling occurs commonly among middle-age and older adults and is sometimes associated with functional limitations. The Editors Knee buckling is the sudden loss of postural support across the knee at a time of weight bearing. Affected persons often characterize this phenomenon as giving way. One study has suggested that the prevalence of knee buckling is high in selected persons seeking physical therapy and stability training for knee osteoarthritis (1). However, the prevalence of knee buckling in the community and its effect on physical function have not been described. Buckling occurs mostly in persons with knee pain, and frequent knee pain affects about 25% of adults (2). Many of these persons have osteoarthritis of the knee (3). Whereas buckling and instability are a focus of orthopedic literature, these phenomena are neglected in medicine textbooks in chapters on knee pain or osteoarthritis (4, 5). When buckling is discussed, it is identified as evidence of an internal derangement, such as an anterior cruciate ligament (ACL) tear (5). A search of MEDLINE for articles on knee instability (subject), buckling, or giving way (words in title or abstract) from 1966 through June 2007 revealed that articles on knee buckling or instability were found almost exclusively in the orthopedic literature, where it was noted as a complication of surgery (6, 7); a hallmark symptom of ACL tear (8); or a consequence of specific, uncommon conditions, such as patellar dislocation (9). Thus, buckling is not generally described in native, uninjured knees. Buckling and symptoms of impending falling may be treatable or at least prevented, but avoiding activities that precipitate buckling may limit function. Buckling may cause falls and fractures and may help to explain the increased risk for hip fracture in patients with osteoarthritis who have higher bone density than others their age and who, therefore, should be at diminished risk for fracture (10). We sought to characterize the frequency of knee buckling in the previous 3 months among persons from the community. We also evaluated whether buckling was associated with particular characteristics, such as knee or other joint pain or muscular weakness. Finally, we examined the relationship of buckling with physical function and determined whether, independent of knee pain, buckling was associated with limited function. Methods Participants Our study cohort consisted of members of the Framingham Offspring Study and a newly recruited cohort from Framingham, Massachusetts. We combined these participants into a single cohort that we designated the Framingham Osteoarthritis Study cohort. Participants were examined between 2002 to 2005. Participants in the Framingham Offspring Study included surviving descendants and spouses of descendants of participants in the original Framingham Heart Study. The Framingham Osteoarthritis Study is a population-based study of osteoarthritis. As part of a study of the inheritance of osteoarthritis, descendants of the original Framingham Heart Study cohort (the descendants of the original cohort and their spouses constitute the Framingham Offspring) whom we had studied for knee or hand osteoarthritis in earlier Framingham Osteoarthritis studies (11) were selected. This allowed us to examine inheritance patterns of osteoarthritis and genetic linkage. Selected Framingham Offspring were originally examined from 1992 to 1995 (11). All surviving members of this group and those not lost to follow-up were contacted by a letter of invitation, and those interested in participating received a follow-up telephone call to schedule clinic examinations (Appendix Figure 1). Appendix Figure 1. Study flow diagram: the Framingham Offspring Study cohort. ACL = anterior cruciate ligament; MRI = magnetic resonance imaging. The newly recruited participants to the Framingham Osteoarthritis Study were drawn from a random sample of the Framingham, Massachusetts, community. Participants were recruited by using random-digit dialing and U.S. census tract data from 2000 to ensure inclusion of a representative sample of the community (Appendix Figure 2). To increase participation of eligible persons in contacted households, a press release was sent to the local media and public officials and flyers were hung in public areas to heighten awareness of the study, which focused on musculoskeletal health. To be included, persons had to be at least 50 years of age and ambulatory. Bilateral total knee replacement and rheumatoid arthritis were the exclusion criteria. Rheumatoid arthritis was assessed by using a validated survey instrument (12) supplemented by questions about medication use that would reflect treated disease. Participant selection was not based on the presence or absence of knee osteoarthritis or knee pain. Appendix Figure 2. Study flow diagram: the Framingham Osteoarthritis Study community cohort. ACL = anterior cruciate ligament. *Members of Framingham Offspring Study, positive screening for rheumatoid arthritis, magnetic resonance imaging (MRI) contraindicated, bilateral knee replacement, dementia or terminal cancer, or planned to move from area. Declined to participate because of cancer, chronic illness, no interest when received full details of the study, no reason given, no time, declined MRI or radiography, or other reasons. Not done because of claustrophobia, medical contraindications, or problems with scheduling. The study was approved by the Boston University Medical Center institutional review board. All participants provided written informed consent. Assessment of Buckling We informed all participants that we are interested in knee buckling, which is also called giving way. We asked, Have you had an episode in the past 3 months where your knee buckled or gave way? Persons who answered yes were asked to indicate which knee gave way, how many times in the past 3 months they had had such an episode, and whether knee buckling precipitated a fall. We also asked what they were doing when their knee buckled and offered 4 options (they could choose more than 1): walking, going up or down stairs, twisting or turning, or other. We chose a 3-month period because other studies have suggested that recollection of falling was accurate for approximately 3 months after the event (13). We considered a person who answered yes to the initial question on buckling as having experienced buckling. We also examined the subgroup of participants who had had more than 1 episode of buckling in the past 3 months. Pain, Physical Limitation, and Assessment of Risk Factors We asked participants about knee symptoms by using the following question: In the past 30 days, have you had any pain, aching, or stiffness in either of your knees? We considered all persons who said yes to have knee pain. A positive response triggered the follow-up question, Is the pain, aching, or stiffness in your right knee, left knee, or both knees? We assessed knee pain in the past week by using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) questionnaire, a validated instrument for assessment of knee pain and disability (14). To evaluate the effect of buckling on physical function or limitation, we used WOMAC and the Short Form (SF-12) as self-reported measures of physical function or limitation. The WOMAC has a physical function subscale consisting of 17 questions, each of which asks about a different type of activity and whether knee problems limit the respondent in performing those activities. Each item is scored on a scale of 0 to 4 on the basis of the amount of limitation experienced; the total score ranges from 0 to 68, with 68 constituting profound limitation and 0 constituting none. In addition, we used items from the SF-12 (15, 16) to gather information on specific physical functional limitations that might be affected by buckling. The items we focused on from the SF-12 were whether participants were limited in moderate activities, in climbing several flights of stairs, and in the type of work or other activities they could do and whether they accomplished less than they wanted. Isometric quadriceps strength was measured while participants were sitting in a straight-backed chair by using a strain gauge dynamometer strapped to the lower leg. The force exerted when the knee was extended was recorded. Three measurements were made on each leg, and the maximum of the 3 was chosen as the measure of leg strength. For a person, we used the maximal leg strength. More than 90% of participants had all assessments completed during 1 clinic visit. Occasionally, participants were scheduled to return within 2 weeks for magnetic resonance imaging (MRI). Radiographic Assessments All participants underwent bilateral weight-bearing radiography using a posteroanterior fixed-flexion approach with a SynaFlex frame (Synarc, San Francisco, California), and a lateral weight-bearing semiflexed film was obtained according to a recently published protocol (17). Radiographs were scored on the KellgrenLawrence scale (18); a knee was considered to have radiographic osteoarthritis if its grade was 2 or greater. Patellofemoral osteoarthritis was characterized on the lateral view by using a validated approach (19). A bone and joint radiologist and an experienced rheumatologist each read roughly one half of the films. The intrareader value for KellgrenLawrence grade was 0.82, an

The Role of the Meniscus in Knee Osteoarthritis: a Cause or Consequence?

The menisci play a critical protective role for the knee joint through shock absorption and load distribution. Asymptomatic meniscal tears are common and are frequent incidental findings on knee MR imaging of the middle-aged or older patient. A meniscal tear can lead to knee osteoarthritis (OA), but knee OA can also lead to a spontaneous meniscal tear through breakdown and weakening of meniscal structure. A degenerative meniscal lesion in the middle-aged or older patient could suggest early stage knee OA and should be treated accordingly. Surgical resection of nonobstructive degenerate lesions may only remove evidence of the disorder while the OA and associated symptoms proceeds.