Radiographic thumb osteoarthritis: frequency, patterns and associations with pain and clinical assessment findings in a community-dwelling population

Gain-of-function mutant p53 promotes cell growth and cancer cell metabolism via inhibition of AMPK activation

Many mutant p53 proteins (mutp53s) exert oncogenic gain-of-function (GOF) properties, but the mechanisms mediating these functions remain poorly defined. We show here that GOF mutp53s inhibit AMP-activated protein kinase (AMPK) signaling in head and neck cancer cells. Conversely, downregulation of GOF mutp53s enhances AMPK activation under energy stress, decreasing the activity of the anabolic factors acetyl-CoA carboxylase and ribosomal protein S6 and inhibiting aerobic glycolytic potential and invasive cell growth. Under conditions of energy stress, GOF mutp53s, but not wild-type p53, preferentially bind to the AMPKα subunit and inhibit AMPK activation. Given the importance of AMPK as an energy sensor and tumor suppressor that inhibits anabolic metabolism, our findings reveal that direct inhibition of AMPK activation is an important mechanism through which mutp53s can gain oncogenic function.

In vivo kinematics of the thumb carpometacarpal joint during three isometric functional tasks

BACKGROUND

The thumb carpometacarpal (CMC) joint is often affected by osteoarthritis--a mechanically mediated disease. Pathomechanics of the CMC joint, however, are not thoroughly understood due to a paucity of in vivo data.

QUESTIONS/PURPOSES

We documented normal, in vivo CMC joint kinematics during isometric functional tasks. We hypothesized there would be motion of the CMC joint during these tasks and that this motion would differ with sex and age group. We also sought to determine whether the rotations at the CMC joint were coupled and whether the trapezium moved with respect to the third metacarpal.

METHODS

Forty-six asymptomatic subjects were CT-scanned in a neutral position and during three functional tasks (key pinch, jar grasp, jar twist), in an unloaded and a loaded position. Kinematics of the first metacarpal, third metacarpal, and the trapezium were then computed.

RESULTS

Significant motion was identified in the CMC joint during all tasks. Sex did not have an effect on CMC joint kinematics. Motion patterns differed with age group, but these differences were not systematic across the tasks. Rotation at the CMC joint was generally coupled and posture of the trapezium relative to the third metacarpal changed significantly with thumb position.

CONCLUSIONS

The healthy CMC joint is relatively stable during key pinch, jar grasp, and jar twist tasks, despite sex and age group.

CLINICAL RELEVANCE

Our findings indicate that directionally coupled motion patterns in the CMC joint, which lead to a specific loading profile, are similar in men and women. These patterns, in addition to other, nonkinematic influences, especially in the female population, may contribute to the pathomechanics of the osteoarthritic joint.

Death, taxes, and trapeziometacarpal arthrosis

BACKGROUND

Hand surgeons treat trapeziometacarpal arthrosis as if everyone with the disease presents for treatment despite evidence that suggests that trapeziometacarpal arthrosis is a normal part of human aging for which--it seems safe to assume--most people never seek medical attention.

QUESTIONS/PURPOSES

The aims of our study were (1) to confirm the prevalence of radiographic trapeziometacarpal arthrosis in a very large sample and to determine if age and sex are associated with (2) any radiographic evidence of trapeziometacarpal arthrosis; and (3) radiographic evidence of severe trapeziometacarpal arthrosis.

METHODS

A total of 2321 patients 31 years or older with radiographs obtained during treatment of a distal radius fracture at a tertiary care medical center emergency department between 2002 and 2012 were analyzed. Trapeziometacarpal arthrosis was graded using the 3-point scale of Sodha et al. (none, definite, destroyed trapeziometacarpal joint); we used regression analyses to determine the association of age (in 10-year age groups) and sex with the presence of trapeziometacarpal arthrosis.

RESULTS

The prevalence of trapeziometacarpal arthrosis steadily increased to 85% between the ages of 71 and 80 years and reached 100% in women (with 50% of them being classified as severe) aged 91 years or older and 93% in men of 81 years or older. Severe arthrosis was more prevalent at earlier ages among women and reached 35% in women and 34% in men who were 81 years or older. Logistic regression identified higher age as the strongest factor associated with trapeziometacarpal arthrosis, but sex was also a factor.

CONCLUSIONS

Radiographic trapeziometacarpal arthrosis is an expected part of human aging. Given that only three patients in this large cohort had evidence of prior surgery, it seems that most people adapt to trapeziometacarpal arthrosis. Treatments that optimize adaptation in patients who present with trapeziometacarpal arthrosis-related symptoms and disability merit additional study.

Subsets of symptomatic hand osteoarthritis in community-dwelling older adults in the United Kingdom: prevalence, inter-relationships, risk factor profiles and clinical characteristics at baseline and 3-years

OBJECTIVE

To compare the population prevalence, inter-relationships, risk factor profiles and clinical characteristics of subsets of symptomatic hand osteoarthritis (OA) with a view to understanding their relative frequency and distinctiveness.

METHOD

1076 community-dwelling adults with hand symptoms (60% women, mean age 64.7 years) were recruited and classified into pre-defined subsets using physical examination and standardised hand radiographs, scored with the Kellgren & Lawrence (K&L) and Verbruggen-Veys grading systems. Detailed information on selected risk factors was obtained from direct measurement (Body Mass Index (BMI)), self-complete questionnaires (excessive use of hands, previous hand injury) and medical record review (hypertension, dyslipidaemia, type 2 diabetes). Hand pain and disability were self-reported at baseline and 3-year follow-up using Australian/Canadian Osteoarthritis Hand Index (AUSCAN).

RESULTS

Crude population prevalence estimates for symptomatic hand OA subsets in the adult population aged 50 years and over were: thumb base OA (22.4%), nodal interphalangeal joint (IPJ) OA (15.5%), generalised hand OA (10.4%), non-nodal IPJ OA (4.9%), erosive OA (1.0%). Apart from thumb base OA, there was considerable overlap between the subsets. Erosive OA appeared the most distinctive with the highest female: male ratio, and the most disability at baseline and 3-years. A higher frequency of obesity, hypertension, dyslipidaemia, and metabolic syndrome was observed in this subset.

CONCLUSION

Overlap in the occurrence of hand OA subsets poses conceptual and practical challenges to the pursuit of distinct phenotypes. Erosive OA may nevertheless provide particular insight into the role of metabolic and cardiovascular risk factors in the pathogenesis of OA.

Carpal tunnel syndrome and radiographically evident basal joint arthritis of the thumb in elderly Koreans

BACKGROUND

Previous studies have suggested a high prevalence of carpal tunnel syndrome in patients seeking treatment for basal joint arthritis of the thumb. The purpose of this study was to compare the prevalence of carpal tunnel syndrome between individuals with and those without radiographic evidence of basal joint arthritis of the thumb in the general elderly Korean population, and to determine if there is a correlation between the severity of carpal tunnel syndrome shown by electrophysiological studies and the severity of basal joint arthritis as seen on radiographs.

METHODS

We evaluated hand radiographs and nerve conduction studies of 192 men and 176 women (more than sixty-five years of age) who participated in the Korean Longitudinal Study on Health and Aging. The basal joint of the thumb was assigned a grade for osteoarthritis of 0 to 4 on radiographs with use of the Kellgren and Lawrence criteria. The diagnosis of carpal tunnel syndrome was based on the combination of a positive response to survey questions and a positive nerve conduction study. Motor distal latency and motor conduction velocity were measured to assess the electrophysiological severity of carpal tunnel syndrome.

RESULTS

The prevalence of carpal tunnel syndrome was 16.7% in the group with basal joint arthritis and 10.9% in the group without basal joint arthritis, a difference that was not significant (p = 0.249). Neither motor distal latency nor motor conduction velocity was significantly correlated with the severity of the basal joint arthritis in the entire group of 368 study subjects (p = 0.154 and p = 0.662, respectively) or in those with carpal tunnel syndrome (p = 0.603 and p = 0.998, respectively).

CONCLUSIONS

This study of Koreans who were more than sixty-five years of age showed that the prevalence of carpal tunnel syndrome is similar in patients with and those without radiographic findings of basal joint arthritis of the thumb. We found no correlation between the electrophysiological severity of carpal tunnel syndrome and the severity of basal joint arthritis.

Hand osteoarthritis--a heterogeneous disorder

Hand osteoarthritis (OA) is a prevalent disorder. Hand OA is not one single disease, but a heterogeneous group of disorders. Radiographic signs of hand OA, such as osteophytes or joint space narrowing, can be found in up to 81% of the elderly population. Several hand OA subsets--such as nodal interphalangeal OA, thumb base OA and erosive OA--can be discriminated. Furthermore, the experience of symptoms and the course of the disease differ between patients. Studies that used well-defined study populations with longitudinal follow-up have shown that similarities and differences can be observed in the pathogenesis, epidemiology and risk factors of the various hand OA subsets. Erosive OA in particular, characterized by erosive lesions on radiographical images, has a higher clinical burden and worse outcome than nonerosive hand OA. Imaging modalities (such as ultrasonography) have increased our knowledge of the role of inflammation of the disease. Our understanding of the heterogeneous nature of hand OA can eventually lead to increased knowledge of the pathogenesis of, and ultimately new treatment modalities for, this complex disease.