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L Sharma

Publications and source records attributed to L Sharma.

At least 19 recordsLinked to original sources
PubMed2000

The mechanism of the effect of obesity in knee osteoarthritis: the mediating role of malalignment.

OBJECTIVE: Obesity is most strongly linked to osteoarthritis (OA) at the knee. Varus malalignment was examined as a possible local mediator that may increase the impact of body weight at the knee, versus the hip or ankle. Compartment load distribution is more equitable in valgus than in varus knees, and valgus knees may better tolerate obesity. We therefore tested whether 1) body mass index (BMI) is correlated with OA severity in varus knees, 2) the BMI-OA severity correlation is weaker in valgus than in varus knees, 3) BMI is correlated with the severity of varus malalignment, and 4) the BMI-medial tibiofemoral OA severity relationship is reduced after controlling for varus malalignment. METHODS: In 300 community-recruited patients with knee OA, 2 groups (varus and valgus) were identified based on dominant knee alignment on a full-limb radiograph, i.e., the angle formed by the intersection of the femoral and tibial mechanical axes. Severity of knee OA was assessed by measurement of the narrowest joint space width on radiographs of knees in a fluoroscopy-confirmed semiflexed position. RESULTS: Alignment direction was symmetric (or neutral in 1 limb) in 87% of patients. One hundred fifty-four patients had varus knees and 115 had valgus knees. BMI correlated with OA severity in the varus group (r = -0.29, P = 0.0009) but not in the valgus group (r = -0.13, P = 0.17). BMI correlated with malalignment in those with varus knees (r = 0.26) but not in those with valgus knees (r = 0.16). The partial correlation of BMI and OA severity, controlling for sex, was reduced from 0.24 (P = 0.002) to 0.04 (P = 0.42) when varus malalignment was added to the model. CONCLUSION: BMI was related to OA severity in those with varus knees but not in those with valgus knees. Much of the effect of BMI on the severity of medial tibiofemoral OA was explained by varus malalignment, after controlling for sex. Whether it precedes or follows the onset of disease, varus malalignment is one local factor that may contribute to rendering the knee most vulnerable to the effects of obesity.

Aged↗
PubMed1999

Does laxity alter the relationship between strength and physical function in knee osteoarthritis?

OBJECTIVE: Since strengthening interventions have had a lower-than-expected impact on patient function in studies of knee osteoarthritis (OA) and it is known that laxity influences muscle activity, this study examined whether the relationship between strength and function is weaker in the presence of laxity. METHODS: One hundred sixty-four patients with knee OA were studied. Knee OA was defined by the presence of definite osteophytes, and patients had to have at least a little difficulty with knee-requiring activities. Tests were performed to determine quadriceps and hamstring strength, varus-valgus laxity, functional status (Western Ontario and McMaster Universities Osteoarthritis Index Physical Functioning subscale [WOMAC-PF] and chair-stand performance), body mass index, and pain. High and low laxity groups were defined as above and below the sample median, respectively. RESULTS: Strength and chair-stand rates correlated (r = 0.44 to 0.52), as did strength and the WOMAC-PF score (r = -0.21 to -0.36). In multivariate analyses, greater laxity was consistently associated with a weaker relationship between strength (quadriceps or hamstring) and physical functioning (chair-stand rate or WOMAC-PF score). CONCLUSION: Varus-valgus laxity is associated with a decrease in the magnitude of the relationship between strength and physical function in knee OA. In studies examining the functional and structural consequences of resistance exercise in knee OA, stratification of analyses by varus-valgus laxity should be considered. The effect of strengthening interventions in knee OA may be enhanced by consideration of the status of the passive restraint system.

Adult↗
PubMed1999

Grip strength and the risk of developing radiographic hand osteoarthritis: results from the Framingham Study.

OBJECTIVE: In knees, quadriceps strength may protect against osteoarthritis (OA). Muscle activity is a major determinant of forces at the hand joints, and grip is a common task during which high muscle forces are sustained, especially at the proximal hand joints (metacarpophalangeal [MCP] joints and thumb base). This longitudinal study of radiographic hand OA examined the association between incident OA at different hand joints and maximal grip strength. METHODS: Four hand joint groups were studied: distal interphalangeal (DIP), proximal interphalangeal (PIP), MCP, and the base of the thumb (carpometacarpal and scaphotrapezial combined). Subjects were members of the Framingham OA Study who had a baseline radiograph in 1967-1969 and a followup radiograph in 1992-1993 (mean followup 24 years) and had no prevalent radiographic OA in any hand joint at baseline. Incident disease was defined as development of OA defined as a modified Kellgren/Lawrence grade of > or =2. Grip strength was measured in kilograms by dynamometer in 1958-1961 and again in 1960-1963, and the 2 measures were averaged and divided into sex-specific tertiles. Joint-based analysis was performed by adjusting for age, physical activity, and occupational category using the lowest grip strength tertile as the referent. RESULTS: Baseline and followup radiographs were obtained from 746 subjects. Of these, 453 subjects with no prevalent OA at baseline were eligible for analysis. In men, higher maximal grip strength was associated with an increased risk of OA in the PIP (highest tertile odds ratio [OR] 2.8 compared with lowest tertile, 95% confidence interval [95% CI] 1.2-6.7), MCP (highest tertile OR 2.9, 95% CI 1.1-7.4), and thumb base joints (highest tertile OR 2.8, 95% CI 1.1-7.4). In women, there was increased risk of OA in the MCP joints (highest tertile OR 2.7, 95% CI 1.1-6.4). CONCLUSION: Men with high maximal grip strength are at increased risk for the development of OA in the PIP, MCP, and thumb base joints, and women, in the MCP joints. No association was found between maximal grip strength and incident OA in the DIP joints of men or women.

Female↗
PubMed1999

Laxity in healthy and osteoarthritic knees.

OBJECTIVE: Although it is a cause of osteoarthritis (OA) in animal models, laxity in human knee OA has been minimally evaluated. Ligaments become more compliant with age; whether this results in clinical laxity is not clear. In theory, laxity may predispose to OA and/or result from OA. Our goals were to examine the correlation of age and sex with knee laxity in control subjects without OA, compare laxity in uninvolved knees of OA patients with that in older control knees, and examine the relationship between specific features of OA and knee laxity. METHODS: We assessed varus-valgus and anteroposterior laxity in 25 young control subjects, 24 older control subjects without clinical OA, radiographic OA, or a history of knee injury, and 164 patients with knee OA as determined by the presence of definite osteophytes. A device was designed to assess varus-valgus laxity under a constant varus or valgus load while maintaining a fixed knee flexion angle and thigh and ankle immobilization. Radiographic evaluations utilized protocols addressing position, beam alignment, magnification, and landmark definition; the semiflexed position was used, with fluoroscopic confirmation. RESULTS: In the controls, women had greater varus-valgus laxity than did men (3.6 degrees versus 2.7 degrees; 95% confidence interval [95% CI] of difference 0.38, 1.56; P = 0.004), and laxity correlated modestly with age (r = 0.29, P = 0.04). Varus-valgus laxity was greater in the uninvolved knees of OA patients than in older control knees (4.9 degrees versus 3.4 degrees; 95% CI of difference 0.60, 2.24; P = 0.0006). In OA patients, varus-valgus laxity increased as joint space decreased (slope -0.34; 95% CI -0.48, -0.19; P < 0.0001) and was greater in knees with than in knees without bony attrition (5.3 degrees versus 4.5 degrees; 95% CI of difference 0.32, 1.27; P = 0.001). CONCLUSION: Greater varus-valgus laxity in the uninvolved knees of OA patients versus older control knees and an age-related increase in varus-valgus laxity support the concept that some portion of the increased laxity of OA may predate disease. Loss of cartilage/bone height is associated with greater varus-valgus laxity. These results raise the possibility that varus-valgus laxity may increase the risk of knee OA and cyclically contribute to progression.

Aged↗
PubMed1999

Proprioceptive impairment in knee osteoarthritis.

Proprioception, the perception of limb position in space, is derived from afferent signals originating primarily from musculotendinous and joint receptors. Proprioception is critical to the maintenance of joint stability. Studies have demonstrated that proprioception is less accurate in patients with knee osteoarthritis versus elderly control subjects, in healthy older versus younger subjects, and in the setting of other conditions affecting the knee including anterior cruciate ligament deficiency and hypermobility syndrome. Possible pathways between proprioceptive inaccuracy, knee osteoarthritis, and related knee disorders are described.

Animals↗
PubMed1999

Effect of knee pain on joint loading in patients with osteoarthritis.

Treatment of patients with osteoarthritis is often directed at relieving pain and restoring function. Pain, however, may serve as a protective mechanism in that patients may decrease their levels of activity or alter the manner in which they perform activities in response to pain. Pain reduction may result in increased loads on the joints during dynamic activities, which may result in more rapid disease progression. Therefore, treatment methods that relieve pain but result in a loss of the protective mechanisms associated with pain may not be beneficial in the long term. This mechanism of decreased pain associated with an overuse of the degenerated joint has been referred to as an "analgesic arthropathy." This article discusses common treatments or interventions used for patients with knee osteoarthritis and their potential effects on pain levels and loads at the knee joint during walking. Understanding the relationship between treatment methods, pain, and the knee joint loads during walking is important because walking is the most frequently performed activity, and the cyclic loads at the knee joint during walking are high.

Animals↗
PubMed1998

Knee adduction moment, serum hyaluronan level, and disease severity in medial tibiofemoral osteoarthritis.

OBJECTIVE: The adduction moment at the knee during gait is the primary determinant of medial-to-lateral load distribution. If the adduction moment contributes to progression of osteoarthritis (OA), then patients with advanced medial tibiofemoral OA should have higher adduction moments. The present study was undertaken to investigate the hypothesis that the adduction moment normalized for weight and height is associated with medial tibiofemoral OA disease severity after controlling for age, sex, and pain level, and to examine the correlation of serum hyaluronan (HA) level with disease severity and with the adduction moment in a subset of patients. METHODS: Fifty-four patients with medial tibiofemoral OA underwent gait analysis and radiographic evaluation. Disease severity was assessed using the Kellgren-Lawrence (K-L) grade and medial joint space width. In a subset of 23 patients with available sera, HA was quantified by sandwich enzyme-linked immunosorbent assay. Pearson correlations, a random effects model, and multivariate regression models were used. RESULTS: The adduction moment correlated with the K-L grade in the left and right knees (r = 0.68 and r = 0.60, respectively), and with joint space width in the left and right knees (r = -0.45 and r = -0.47, respectively). The relationship persisted after controlling for age, sex, and severity of pain. The partial correlation between K-L grade and adduction moment was 0.71 in the left knees and 0.61 in the right knees. For every 1.0-unit increase in adduction moment, there was a 0.63-mm decrease in joint space width. In the subset of patients in whom serum HA levels were measured, HA levels correlated with medial joint space width (r = -0.55), but not with the adduction moment. CONCLUSION: There is a significant relationship between the adduction moment and OA disease severity. Serum HA levels correlate with joint space width but not with the adduction moment. Longitudinal studies will be necessary to determine the contribution of the adduction moment, and its contribution in conjunction with metabolic markers, to progression of medial tibiofemoral OA.

Aged↗
PubMed1997

Is knee joint proprioception worse in the arthritic knee versus the unaffected knee in unilateral knee osteoarthritis?

OBJECTIVE: Neuromuscular joint protection requires proprioceptive input and motor output. Impairment of proprioception in knee osteoarthritis (OA) may contribute to, and/or result from, the disease. If this impairment was exclusively a local result of OA, a between-knee difference would be expected in patients with unilateral OA (UOA). To explore causal directions, 2 hypotheses were tested: 1) proprioception is worse in UOA patients versus elderly controls; 2) proprioception is worse in the arthritic knee versus the unaffected knee in UOA patients. METHODS: Twenty-eight UOA patients (Kellgren-Lawrence grade > or =2 in 1 knee and <2 in the other knee) and 29 elderly controls were enrolled. The unaffected knee of each UOA patient and both knees of the elderly controls were required to meet symptom, examination, and radiographic criteria. Proprioception (detection threshold of joint displacement after slow, passive, automated knee motion), body mass index, pain, functional status, range of motion, and laxity were measured. RESULTS: UOA patients had worse proprioception than did elderly controls, in either knee. A between-knee difference was not found in UOA patients. CONCLUSION: Impaired proprioception is not exclusively a local result of disease in knee OA. The relative importance of impaired proprioception in the development and progression of knee OA will require longitudinal study.

Aged↗
PubMed1997

Effect of age and osteoarthritis on knee proprioception.

OBJECTIVE: To test the hypotheses that 1) knee position sense declines with age; 2) patients with osteoarthritis (OA) have worse knee position sense than elderly controls; and 3) knee position sense is correlated with functional status. METHODS: The threshold for detection of knee joint displacement was measured in 30 patients with bilateral knee OA (Kellgren/Lawrence grade > or =2 in both knees), 29 elderly controls (who met clinical and radiographic criteria for exclusion of OA), and 25 young controls. Range of motion, laxity, radiographic severity, and functional status were also assessed. RESULTS: A moderate correlation was found between joint displacement detection threshold and age (r = 0.598 and r = 0.501 for the right knee and the left knee, respectively). The threshold was substantially and significantly different between the OA patients and the elderly controls. Proprioceptive impairment was associated with worse disease-specific functional status. CONCLUSION: Proprioception declines with age, and is further impaired in elderly patients with knee OA. Poor proprioception may contribute to functional impairment in knee OA.

Adult↗
PubMed1997

Impaired proprioception and osteoarthritis.

The increase in the prevalence of osteoarthritis (OA) with age may be due in part to increased joint load resulting from age-related declines in neuromechanical factors, including joint position sense or proprioception. Several studies have demonstrated that knee proprioception is worse in knee OA patients versus age-matched control subjects. Functional consequences of impaired proprioception may include lower gait velocity, shorter stride length, and slower stair walking time. Some studies have shown that proprioception can be enhanced by wearing an elastic bandage or similar orthoses and by muscle training. A variety of other interventions have been proposed as well. To date studies of proprioception in OA patients have been cross-sectional. Theoretically, impaired proprioception might contribute toward or result from OA. A paradigm depicting directions in the relationship between proprioception impairment and OA is offered. Longitudinal data are badly needed to elucidate cause and effect and to determine the relative importance of impaired proprioception in disease progression. The relationship between sensory input and protective or damaging muscle activity has been minimally evaluated in the setting of OA. In studies of clinical conditions related to OA, experimental effusions had no effect on proprioception. Proprioception was worse in hypermobility syndrome patients versus age-matched controls. Anterior cruciate ligament insufficiency is associated with a decline in proprioception.

Humans↗
PubMed1997

Role of growth hormone status in the outcome of total knee replacement.

The objective was to assess whether the aging related, variable decline in growth hormone influences total knee replacement outcome. In this prospective cohort study, consecutive patients who underwent unilateral total knee replacement and who met criteria were enrolled from the practice of 1 orthopaedic surgeon at a university hospital. Participants were evaluated 1 month before and 3 months after total knee replacement. Evaluators were not involved in patient care. The primary outcome measure was the Medical Outcome Study 36-item Short Form Health Survey Physical Functioning Scale score 3 months after total knee replacement. In a multiple regression analysis performed to assess the influence of growth hormone status, controlling for social support, body mass index, gender, previous reconstruction, mental health, motivation, and baseline physical functioning, only mental health contributed significantly to outcome. Mental health accounted for 18% of outcome variance. Growth hormone levels did not predict functional status after total knee replacement. Psychological status contributes significantly to total knee replacement physical functional outcome.

Age Factors↗
PubMed1996

Human T-cell lymphotropic virus type 1-associated myelopathy, Sjögren syndrome, and lymphocytic pneumonitis.

OBJECTIVE: To describe the first case of human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy, Sjögren syndrome, and lymphocytic pneumonitis in a nonendemic area. BACKGROUND: Retroviruses are implicated in the pathogenesis of autoimmune diseases, including Sjögren syndrome. Asymptomatic lymphocytic pneumonitis is prevalent in HTLV-1-associated myelopathy. There are 7 case reports with the combination of HTLV-1-associated myelopathy, Sjögren syndrome, and lymphocytic pneumonitis, all of them in endemic areas for HTLV-1. DESIGN: Case report and literature review. RESULTS: A 40-year-old Creole woman from New Orleans, La, presented with progressive spastic paraparesis and exertional dyspnea. Review of systems revealed chronic complaints consistent with sicca syndrome. She was found to have HTLV-1-associated myelopathy by polymerase chain reaction in the cerebrospinal fluid. Increased levels of SSA, positive results on a Schirmer test, and the findings of biopsy of the minor salivary gland were consistent with Sjögren syndrome. A lung biopsy specimen showed marked lymphocytic infiltration. CONCLUSIONS: The present case raises questions about the role of HTLV-1 in the development of autoimmunity. It also happens to be a unique occurrence in a nonendemic area.

Adult↗
PubMed1996

The effects of cortical lesions on recognition of object context in a visuomotor task in the Mongolian gerbil.

Two experiments were carried out in order to determine the effects of either parietal or temporal lesions on performance in a depth vision task in which gerbils normally use retinal image size (RIS) as a cue to distance. In the first experiment, gerbils were trained to jump to two training targets that differed in size and which were always presented with distinctive local features and in a particular spatial location. After lesions, gerbils were presented with further training trials and sets of probe trials in which they were presented with targets that differed in width from the training targets, and sets of local features and distal cues that either matched or mismatched those presented during training. Shams and temporal animals made predictable over- or underjumps when local feature and distal information matched, and stopped using retinal image size when they did not match. Parietal animals did not use retinal image size either during the match or the mismatch conditions. In a second experiment, gerbils with parietal lesions were shown capable of using retinal image size in a simpler task that did not contain distinguishing local features or distal cues. Taken together, these results suggest that parietal lesions in gerbils disrupt object recognition, when the purpose of the recognition process is to complete a distance estimate for a visuomotor act.

Animals↗
PubMed1996

Prognostic factors for functional outcome of total knee replacement: a prospective study.

BACKGROUND: The objective was to investigate whether baseline physical functioning, medical, psychosocial, or demographic variables predict functional outcome in patients undergoing total knee replacement. METHODS: A prospective cohort study was performed between December 1991 and August 1993. Consecutive, unilateral tricompartmental total knee replacement patients aged > or = 55 yr with osteoarthritis, who met criteria, were enrolled and evaluated one month before and 3 months after total knee replacement. The primary outcome measure was the Medical Outcome Study 36 Item Short Form Health Survey (known as the SF36) Physical Functioning Scale score. The outcome evaluator was not involved in patient care. RESULTS: A hierarchical multiple regression analysis was performed to calculate the contribution of baseline variables to TKR outcome. Of the 27% of outcome variance explained by the model, demographic variables accounted for 4%, psychosocial variables (motivation, role functioning-emotional, and social functioning) for 19% (p = .013), medical variables (previous reconstruction, comorbidity, body mass index, bodily pain) for 2%, and baseline physical function for 2%. CONCLUSIONS: Psychosocial variables are significantly related to total knee replacement functional outcome. Assessment of baseline psychological and social functioning may identify a subset of patients at risk for worse outcome. Specific interventions for these patients should be developed and evaluated as components of patient management prior to and after the procedure.

Activities of Daily Living↗
PubMed1996

Decline of plasma growth hormone binding protein in old age.

Aging is associated with a progressive decline in GH secretion and serum insulin-like growth factor (IGF)-I levels. This change in the GH-IGF axis is thought to contribute to the changes in body composition associated with aging, such as a loss in lean body mass and an increase in adipose tissue mass. Although the decrease in GH secretion starts in the third decade of life, marked changes in muscle mass and strength become apparent only much later. To assess whether a component of GH resistance supervenes in senescence, we studied plasma GH binding protein (GHBP) levels in 50 normal subjects between the ages of 61 and 98 yr. The GHBP is a soluble, circulating ectodomain of the GH receptor (GHR); its plasma level is thought to reflect GHR levels in tissues and, hence, GH responsivity. GHBP activity in plasma declined progressively between age 60 and 98 yr. The GHBP levels in nonagenarians was about half that of persons aged 60-65. This contrasts with younger adults, where GHBP levels remain relatively stable between the ages of 20 and 60. We conclude that in advanced age. GHBP and, by inference, GHR levels, decrease, which may add an element of GH resistance to the already compromised GH secretion status, thereby further contributing to the changes in body composition and frailty in the elderly.

Aged↗
PubMed1995

Clinical significance of anti-At(a).

Ata is a high-frequency red blood cell (RBC) antigen. Anti-At(a) has been reported in rare At(a-) black subjects. We report two cases of anti-At(a). A clinically significant anti-At(a) was found in a 26-year-old black woman with systemic lupus erythematosus. The patient had a transfusion reaction with chills and nausea during a RBC survival study, and 95% of the radiolabeled At(a+) RBCs were destroyed within 3 h. A concurrently performed monocyte monolayer assay was strongly reactive. Anti-At(a) thus can cause rapid hemolysis of transfused RBCs, but At(a-) donor units are extremely scarce in rare donor registries. A second patient at our hospital had anti-At(a) which did not affect her newborn. She also had autoimmune disease, insulin-dependent diabetes mellitus.

Adult↗