Gunnar B. Flugsrud

The effect of middle-age body weight and physical activity on the risk of early revision hip arthroplasty: a cohort study of 1,535 individuals.

Background Overweight and a high level of physical activity are known risk factors for loosening of a total hip arthroplasty (THA) due to primary osteoarthritis. We wanted to investigate how these factors, together with age and sex, affect the risk of revision surgery. Patients and methods We matched data from the Norwegian Arthroplasty Register with information on risk factors collected at a cardiovascular screening. We identified 1,535 primary THAs in the screened cohort (930 cemented implants using well-documented cement). Of the participants included, 969 were female. Mean age at screening was 49 years, at primary THA 63 years, and 69 years at the end of follow-up. We used Cox regression analysis to estimate relative risks (RRs). Event was defined as implant revision due to aseptic loosening of cup, stem or both. Follow-up was time from primary THA to event or censoring. Results Men were at greater risk than women of loosening of the femoral stem (RR 2.0, 95% CI 1.3–3.2). Both men and women with upper-quartile body weight were at increased risk of revision due to loosening of the stem (RR 2.5 and 2.7, respectively). Men with a high level of physical activity during leisure time were at increased risk of revision due to loosening of the cup (RR 4.8, 95% CI 1.3–18). In the multivariate model with adjustment for activity, there was little association between age at primary THA and risk of revision due to loosening. Interpretation We found that body weight and physical activity recorded long before THA affected the survival of total hip arthroplasties. Controlling for these variables weakened the association between age at primary surgery and aseptic loosening. Men had an increased risk of loosening of the femoral stem, also after controlling for lifestyle factors.

Weight gain and the risk of total hip replacement a population-based prospective cohort study of 265,725 individuals

OBJECTIVE To study the association between change in the body mass index (BMI) at different ages and the risk of a later total hip replacement (THR) due to primary osteoarthritis (OA). DESIGN A total of 265,725 individuals who had two repeated measurements of weight and height were included from national health screenings. These individuals were followed prospectively. The data were matched with the Norwegian Arthroplasty Register and 4,442 of these individuals were identified as having received a THR for primary OA. Cox proportional hazard regression was used to calculate sex-specific relative risks for having a THR according to age at screening and BMI change. RESULTS Men and women aged 20 years or younger at the first screening in the quartile with the greatest BMI change per year had more than twice the risk of later having a THR compared with those in the quartile with the smallest BMI change per year. For men older than 30 years at the first screening, there was no relationship between BMI gain, or weight gain, and later risk of THR. For older women, BMI gain was associated with risk of THR, but to a lesser degree than in younger women. CONCLUSION There was a clear relationship between change in BMI and the risk of later THR in young men and women, whereas the association was absent in older men and weaker in older women. It is important to focus on weight control to prevent future OA, and the preventive strategy should be focused on the young population.

Cemented femoral impaction bone grafting for severe osteolysis in revision hip arthroplasty. Good results at 4-year follow-up of 10 patients.

Abstract Ten hips underwent impaction bone grafting with cement as revision of the femoral stem for severe osteolysis. At clinical follow-up of a median of 4 years (range 3.0–4.6 years) there were no failures. The median Harris hip score increased from 53 to 80, and pain score from 25 to 40. Radiographically, there was no resorption of the impacted grafts. All of the 9 patients with radiographical follow-up of more than 1 year showed trabecular remodelling, 7 of whom had signs of cortical repair. Subsidence was a median of 2 mm, with the maximum subsidence being 5 mm. The results appeared clinically stable after 4 years with radiographic reconstitution of the bone stock.

Weight gain and the risk of knee replacement due to primary osteoarthritis: A population based, prospective cohort study of 225,908 individuals

OBJECTIVE To study the association between weight gain and the risk of knee replacement (KR) due to primary osteoarthritis (OA), and to evaluate whether the association differs by age. DESIGN 225,908 individuals from national health screenings with repeated measurements of height and weight were followed prospectively with respect to KR identified by linkage to the Norwegian Arthroplasty Register. Cox proportional hazard regression was used to calculate sex-specific relative risks (RR) of KR according to change in Body Mass Index (BMI) and weight, corresponding analyses were done for age categories at first screening. RESULTS During 12 years of follow up, 1591 participants received a KR due to primary OA. Men in the highest quarter of yearly change in BMI had a RR of 1.5 (95% confidence interval (CI) 1.1-1.9) of having a KR compared to those in the lowest quarter. For women the corresponding RR was 2.4 (95% CI 2.1-2.7). Men under the age of 20 at the first screening had a 26% increased risk for KR per 5 kg weight gain, for women the corresponding increase was 43%. At older age the association became weaker, and in the oldest it was lost. CONCLUSIONS Weight gain increases the risk for later KR both in men and women. The impact of weight gain is strongest in the young, at older age the association is weak or absent. Our study suggests that future OA may be prevented by weight control and that preventive measures should start at an early age.

Hand, hip and knee osteoarthritis in a Norwegian population-based study - The MUST protocol

BackgroundKnowledge about the prevalence and consequences of osteoarthritis (OA) in the Norwegian population is limited. This study has been designed to gain a greater understanding of musculoskeletal pain in the general population with a focus on clinically and radiologically confirmed OA, as well as risk factors, consequences, and management of OA.Methods/DesignThe Musculoskeletal pain in Ullensaker STudy (MUST) has been designed as an observational study comprising a population-based postal survey and a comprehensive clinical examination of a sub-sample with self-reported OA (MUST OA cohort). All inhabitants in Ullensaker municipality, Norway, aged 40 to 79 years receive the initial population-based postal survey questionnaire with questions about life style, general health, musculoskeletal pain, self-reported OA, comorbidities, health care utilisation, medication use, and functional ability. Participants who self-report OA in their hip, knee and/or hand joints are asked to attend a comprehensive clinical examination at Diakonhjemmet Hospital, Oslo, including a comprehensive medical examination, performance-based functional tests, different imaging modalities, cardiovascular assessment, blood and urine samples, and a number of patient-reported questionnaires including five OA disease specific instruments. Data will be merged with six national data registries. A subsample of those who receive the questionnaire has previously participated in postal surveys conducted in 1990, 1994, and 2004 with data on musculoskeletal pain and functional ability in addition to demographic characteristics and a number of health related factors. This subsample constitutes a population based cohort with 20 years follow-up.DiscussionThis protocol describes the design of an observational population-based study that will involve the collection of data from a postal survey on musculoskeletal pain, and a comprehensive clinical examination on those with self-reported hand, hip and/or knee OA. These data, in addition to data from national registries, will provide unique insights into clinically and radiologically confirmed OA with respect to risk factors, consequences, and management.

Weight change and the risk of total hip replacement.

Background: We examined the effect of adult weight change on risk for total hip replacement resulting from primary osteoarthritis, using a prospective study design. Methods: We linked data on body mass index and body weight from 3 screening surveys in 3 Norwegian counties (mean ages at screenings 34, 43, and 47 y; n = 38,868) with follow-up data on total hip replacement (n = 572). Mean age at the start of follow up was 55 years, and mean duration of follow up was 9 years. For each participant we calculated a rate of weight change (weight slope) by linear regression of body weight versus time from the first through the third screening. Results: Among men, mean weight change from first to last screening was +9.8 kg in the highest quartile and −3.7 kg in the lowest quartile. In women, the corresponding figures were +9.5 kg in the highest quartile and −5.2 kg in the lowest quartile. There was no association of weight slope, absolute weight change, or relative weight change between screenings with later total hip replacement resulting from primary osteoarthritis. We saw no change in the association between body mass index and later hip arthroplasty as the participants’ age increased from 34 to 47 years at the 3 screenings. Conclusion: The risk for later total hip replacement resulting from primary osteoarthritis was unaffected by weight change during the fourth and fifth decades of life. The dose-response association between adult body mass index and later total hip replacement was similar across these age groups.

Incidence of total hip or knee replacement due to osteoarthritis in relation to thyroid function: a prospective cohort study (The Nord-Trøndelag Health Study)

BackgroundTo study whether thyroid function was associated with risk of hip or knee replacement due to primary osteoarthritis.MethodsIn a prospective cohort study, data from the second and third survey of the Nord-Trøndelag Health Study were linked to the Norwegian Arthroplasty Register in order to identify total hip or knee replacement as a result of primary osteoarthritis.ResultsAmong 37 891 participants without previously known thyroid disease we recorded 978 total hip replacements (THRs) and 538 total knee replacements (TKRs) during a median follow-up time of 15.7 years. The analyses were adjusted for sex, age, BMI (body mass index), smoking, physical activity and diabetes. We did not find any association between TSH (thyroid stimulating hormone) and THR or TKR due to osteoarthritis. Neither were changes in TSH over time, or overt hypo- or hyperthyroidism, associated with incidence of THR or TKR.ConclusionNo association was found between thyroid function and hip or knee joint replacement due to osteoarthritis.

Metabolic syndrome as a risk factor for total hip or knee replacement due to primary osteoarthritis: a prospective cohort study (the HUNT study and the Norwegian Arthroplasty Register)

Objective Biochemical changes associated with obesity may accelerate osteoarthritis beyond the effect of mechanical factors. This study investigated whether metabolic syndrome and its components (visceral obesity, hypertension, dyslipidemia and insulin resistance) were risk factors for subsequent total hip replacement (THR) or total knee replacement (TKR) due to primary osteoarthritis. Design In this prospective cohort study, data from the second survey of the Nord-Trøndelag Health Study 2 (HUNT2) were linked to the Norwegian Arthroplasty Register for identification of the outcome of THR or TKR. The analyses were stratified by age (<50, 50–69.9 and ≥70 years) and adjusted for gender, body mass index, smoking, physical activity and education. Results Of the 62,661 participants, 12,593 (20.1%) were identified as having metabolic syndrome, and we recorded 1,840 (2.9%) THRs and 1,111 (1.8%) TKRs during a mean follow-up time of 15.4 years. Cox regression analyses did not show any association between full metabolic syndrome and THR or TKR, except in persons <50 years with metabolic syndrome who had a decreased risk of THR (hazard ratio [HR] 0.58, 95% CI 0.40–0.83). However, when including only participants whose exposure status did not change during follow-up, this protective association was no longer significant. Increased waist circumference was associated with increased risk of TKR in participants <50 years (HR 1.62, 95% CI 1.10–2.39) and 50–69.9 years (HR 1.43, 95% CI 1.14–1.80). Hypertension significantly increased the risk of TKR in participants <50 years (HR 1.38, 95% CI 1.05–1.81), and this risk was greater for men. Conclusion This study found an increased risk of TKR in men <50 years with hypertension and persons <70 years with increased waist circumference. Apart from this, neither metabolic syndrome nor its components were associated with increased risk of THR or TKR due to primary osteoarthritis.

Plate fixation versus intramedullary nailing of completely displaced midshaft fractures of the clavicle: a prospective randomised controlled trial.

Aims This is a prospective randomised controlled trial comparing the functional outcomes of plate fixation and elastic stable intramedullary nailing (ESIN) of completely displaced midshaft fractures of the clavicle in the active adult population. Patients and Methods We prospectively recruited 123 patients and randomised them to either plate fixation or ESIN. Patients completed the Quick Disabilities of the Arm, Shoulder and Hand (DASH) score at one to six weeks post‐operatively. They were followed up at six weeks, three and six months and one year with radiographs, and their clinical outcome was assessed using both the DASH and the Constant Score. Results Plate fixation provided a faster functional recovery during the first six months compared with ESIN, but there was no difference after one year. The duration of surgery was shorter for ESIN (mean 53.4 minutes, 22 to 120) than for plate fixation (mean 69.7 minutes, 35 to 106, p < 0.001). The recovery after ESIN was slower with increasing fracture comminution and with open reduction (p < 0.05). Conclusion Both methods return the patients to their pre‐injury functional levels, but plate fixation has a faster recovery period in comminuted fractures than ESIN. ESIN has a shorter operative time and lower infection and implant rates of failure when using 2.5 mm nails or wider, suggesting that this is the preferred method in mid‐shaft fractures with no comminution, whereas plate fixation is the superior method in comminuted fractures.

The mediating effect of body mass index on the relationship between smoking and hip or knee replacement due to primary osteoarthritis. A population-based cohort study (the HUNT study).

To investigate the total effect of smoking on total hip or knee replacement (THR/TKR) due to primary osteoarthritis (OA) and to quantify the indirect effect of smoking through body mass index (BMI). Participants from the Nord-Trøndelag Health Study (the HUNT Study) were linked to the Norwegian Arthroplasty Register to detect the first THR or TKR due to primary OA. A mediation analysis was used to decompose the total effect of smoking into a direct and indirect effect. BMI was considered a mediator in the analysis. All effects were estimated as hazard ratios (HRs) with 95% confidence intervals (CIs). The indirect effect of smoking mediated through BMI was expressed as a percentage (proportion*100). In total 55 188 participants were followed up during 17.2 years (median). We identified 1322 THRs and 754 TKRs. For men, the total effect of current vs. never smoking revealed a decreased risk of THR (HR 0.59, 95% CI 0.46–0.76) and TKR (HR 0.47, 95% CI 0.32–0.66). For women, current smoking increased the risk of THR (HR 1.34, 95% CI 1.11–1.60). For men, 6% and 7% of the risk reduction for THR and TKR, respectively, was mediated by BMI. We found a negative association between smoking and THR or TKR for men. On the contrary, smoking was associated with increased risk of THR for women. Most of the effect of smoking on joint replacement risk remained unexplained by BMI.