Increased rate of hysterectomy in women undergoing surgery for osteoarthritis of the knee

Defining the rate of, and factors influencing, radiographic progression of osteoarthritis of the canine hip joint

BACKGROUND

This study aimed to define the rate of progression of radiographic osteoarthritis (OA) of the canine hip joint and to describe factors affecting this progression.

METHODS

Dogs that underwent unilateral total hip replacement (THR) were reviewed for the evaluation of radiographic appearance of the non-operated hip joint over time. Standard extended ventrodorsal hip radiographs were taken preoperatively and postoperatively. All images were anonymized, randomized and scored using three different methods. The mean daily change between evaluations was calculated in each individual dog, and the effect of sex, age, body weight, open/closed status of the proximal femoral physis, preoperative severity of OA, time after surgery and their interactions, were investigated as potential influencing factors.

RESULTS

After reviewing the medical records, 163 dogs (468 images) met the inclusion criteria. Consistent across the three scoring systems, radiographic progression of OA was greater in younger (open physis) and spayed female dogs. A subset of seven patients (4.3%) had a faster progression of OA and was considered outliers. No dog was rated as outlier by all three scoring systems.

CONCLUSION

The rate of progression of radiographically assessed coxofemoral OA varies greatly, but is faster in younger, spayed female dogs. Unusually fast progression occasionally occurs.

Potential Effect Modifiers of the Association Between Physical Activity Patterns and Joint Symptoms in Middle-Aged Women

OBJECTIVE

To examine whether body mass index (BMI), menopausal status, and hormone therapy (HT) use modify the association between physical activity (PA) patterns throughout middle age and the incidence and prevalence of joint symptoms in women in later middle age.

METHODS

Data were from 6,661 participants (born 1946-1951) in the Australian Longitudinal Study on Women's Health. Surveys, with questions on joint pain and stiffness, PA, height and weight, menopausal symptoms, and HT use, were completed every 3 years from 1998 to 2010. PA patterns were defined as none or low, low or meeting guidelines, fluctuating, or meeting guidelines at all times (reference pattern). Logistic regression was used to examine the association between PA patterns and prevalent (in 2010) and cumulative incident (1998-2010) joint symptoms and effect modification by patterns in BMI, menopausal status, and HT.

RESULTS

The groups representing fluctuating PA (odds ratio [OR] 1.34 [99% confidence interval (99% CI) 1.04-1.72]) and no or low PA (OR 1.60 [99% CI 1.08-2.35]) had higher odds of incident joint symptoms than those described as meeting guidelines at all times. Stratification by BMI showed that this association was statistically significant in the obese group only. No evidence for effect modification by menopausal status or HT use was found. The findings were similar for prevalent joint symptoms.

CONCLUSION

Maintaining at least low levels of PA throughout middle age was associated with a lower prevalence and incidence of joint symptoms later in life. This apparent protective effect of PA on joint symptoms was stronger in obese women than in under- or normal-weight women, and not related to menopause or HT status.

Estrogens, cartilage, and osteoarthritis

A role for estrogens in osteoarthritis is consistent with the larger increases in women than in men in the incidence and prevalence of hip, knee, and finger osteoarthritis after 50 years of age. Furthermore, hormone replacement therapy for the menopause seems to be associated with a decrease in the prevalence of symptoms and radiological alterations related to hip and knee osteoarthritis. The two estrogen receptors alpha and beta (ERalpha and Erbeta) have been identified in normal and osteoarthritic cartilage, indicating that cartilage can respond to estrogens. Finally, in vivo experiments in animals and in vitro studies have shed light on the mechanisms by which estrogens may influence chondrocyte metabolism.

Hysterectomy and patterns of osteoarthritis. The Ulm Osteoarthritis Study

OBJECTIVE

To determine the association between hysterectomy (HE) and patterns of osteoarthritis (OA) METHODS: We performed a large cross-sectional study including 504 female patients admitted for arthroplasty of knee or hip joint. Patients with OA were categorized as having bilateral or generalized OA (GOA) according to the presence of radiographic OA in the contralateral or different finger joints. Odds ratios (OR) and their 95% confidence intervals (CI) for the association between HE and OA patterns were estimated adjusting for potential confounders.

RESULTS

Hysterectomy (HE) was reported by 24.9 percent of the patients. Bilateral OA was present in 86.2 percent and GOA was present in 33.3 percent of the patients. HE was not associated with bilateral OA (adjusted OR=0.9; 95% CI: 0.5-1.8) but with a lower prevalence of GOA (adjusted OR=0.6; CI: 0.3-0.99).

CONCLUSION

In contrast to earlier studies our results suggest that HE might be a marker for a reduced risk for a generalized pattern of OA.

Changes in the incidence and prevalence of rheumatoid arthritis in Kamitonda, Wakayama, Japan, 1965-1996

OBJECTIVE

To evaluate secular trends in the incidence and prevalence of rheumatoid arthritis (RA) in Japan.

METHODS

The incidence and prevalence of RA were determined in a longitudinal population based study in the Kamitonda district, Wakayama, Japan, from 1965 to 1996.

RESULTS

In the study area consisting of about 3000 inhabitants, 16 incident cases, satisfying definite RA by the Rome criteria were detected during the study period. The age and sex adjusted incidence in both men and women combined and the age adjusted incidence in women significantly decreased (p<0.025 and p<0. 01, respectively). The age and sex adjusted prevalence in all inhabitants tended to decrease (p<0.1), and the age adjusted prevalence in women significantly declined (p<0.025). In men, however, neither incidence nor prevalence showed significant change.

CONCLUSIONS

The decline of incidence and prevalence of female RA may be reducible to some environmental changes preferentially occurring more obviously in Japanese women than in men. Because the use of oral contraceptives has been extremely low in Japan, the decline should be explained by other factors.

Expression of genes for estrogen receptors alpha and beta in human articular chondrocytes

OBJECTIVE

To investigate the gene expression of estrogen receptor (ER) alpha and ERbeta in human articular chondrocytes.

METHODS

16 articular cartilage specimens were obtained from 15 patients during surgery. Three of the specimens were from men and 13 from women; three from hip joints and 13 from knee joints; four were normal and 12 showed osteoarthritic cartilage. Total RNA was extracted from the articular chondrocytes and the expression of both ERalpha and ERbeta genes was investigated by the reverse transcription-polymerase chain reaction (RT-PCR) method.

RESULTS

Gene expressions of ERalpha were detected in all specimens and those of ERbeta were found in 15 specimens by the RT-PCR method. There was a significant correlation between the amounts of ERalpha and ERbeta. Expression levels of both genes were significantly higher in men than in women. There were no significant differences in the expression levels of both ER genes between the hip and knee joint sites, nor between normal and osteoarthritic tissues.

CONCLUSION

This study is to our knowledge the first to demonstrate the gene expression of both ERalpha and ERbeta in human articular chondrocytes. Since there are some functional differences between the two receptors, the effects of estrogen on cartilage metabolism should be elucidated by two different receptor mechanisms.

Association of early osteoarthritis of the knee with a Taq I polymorphism of the vitamin D receptor gene

OBJECTIVE

To determine whether a polymorphism of the vitamin D receptor (VDR) gene, already associated with osteoporosis, might also relate to the risk of osteoarthritis (OA).

METHODS

A population cohort of 351 postmenopausal women (ages 45-64 years) was studied using anteroposterior radiographs of the knee, which were graded for OA according to the Kellgren and Lawrence classification system. The VDR genotype was determined by using polymerase chain reaction and by digestion with the restriction enzyme Taq I.

RESULTS

The VDR allele "T" was associated with an increased risk of knee OA compared with the "t" allele, with an odds ratio of 2.82 (95% confidence interval 1.16-6.85; P = 0.02). A dominant pattern of risk was suggested. The frequency of the VDR genotype differed significantly between OA cases and controls (P = 0.03 by Fisher's exact test).

CONCLUSION

A Taq I polymorphism of the VDR gene appears to be associated with an increased risk of knee OA. This is the first genetic locus that has been shown to influence the risk of early knee OA within the general population.