Acute femoral fracture does not compromise the outcome of total hip arthroplasty : 5 year results from a single center cohort study in 2,782 patients.

National arthroplasty registries reveal a higher risk of revision for periprosthetic fracture and dislocation after total hip arthroplasty (THA) in patients with a femoral neck fracture compared to those with osteoarthritis (OA). Since these registries may con- tain confounding factors, we conducted a single center cohort study comparing survival and reason for failure between THA for an acute femoral neck fracture and OA using the same hip prosthesis after a minimum follow-up of 2 years. We retrospectively analyzed 2782 patients who had undergone THA with an Accolade TMZF stem and a Trident cup between March 2009 and September 2014. Primary diagnosis before THA was osteoarthritis (OA group : n=2610) or acute femoral fracture (Fracture group : n=172). Patients in both groups were operated on by the same hip surgeons. Effect of diagnosis on THA survival was analyzed using Cox-regression analysis. Chi-square tests were used to illustrate the different reasons for revision between the groups. Mean follow-up was 4.6 years (2-7.6). A total of 100 revisions were performed. The revision risk was comparable between the OA and Fracture group (HR=1.04, 95% CI :0.46-2.39). No differences were found between the OA and Fracture group with respect to the occurrence of periprosthetic fractures (0.8% vs. 0.6%, p=0.71) and revisions for dislocation (0.6% vs. 1.2%, p=0.38). We found no difference in outcome or reason for revision between THA for OA or femoral neck frac- ture. Using an implant with a proven ODEP rating and having experienced hip surgeons carry out the procedures may be more important than the primary diagnosis.

No Learning Curve of the Direct Superior Approach in Total Hip Arthroplasty.

OBJECTIVES: To assess the learning curve of the direct superior approach (DSA) for total hip arthroplasty (THA) and to compare surgical, clinical, and radiological results with a matched control group using the mini posterior approach (MPA). METHODS: A prospective cohort study was performed from October 2016 to May 2017 including our first 52 patients undergoing THA using the DSA. Patients with primary osteoarthritis or osteonecrosis and a body mass index (BMI) < 35 who were eligible for surgery were included. As a control group, 52 patients who underwent the MPA were included, matched based on age, BMI, and ASA classification. In the DSA group, damage to the iliotibial tract and the distal external rotators, including the external obturator and quadriceps femoris muscles, was avoided. Outcome measures were collected, including surgical time, blood loss, postoperative pain, length of stay, implant position, use of walking aids, patient reported outcome measures (PROM), and complications. Unpaired t-tests were used to analyze differences between the DSA and the MPA group in surgical time, blood loss, length of stay, and acetabular and femoral component position. χ2 -tests were used to analyze mobility and the number of complications. Two-way repeated measures ANOVA was used to analyze pain scores and PROM between the DSA and the MPA groups. RESULTS: The mean surgical time of 61 min (SD 8) in the DSA group was longer (P < 0.001) compared to that in the MPA group, 46 min (SD 12). No differences were found in blood loss, postoperative pain, or mean length of stay in the hospital. After 6 weeks, 94% of the patients in the DSA group were able to walk inside their home without walking aids compared to 90% in the MPA group. The mobility scores were not different after follow up of 6 weeks and 1 year (P = 0.12 and P = 0.36 respectively). All PROM improved postoperatively in both the DSA and the MPA group (P < 0.01). Acetabular cup and femoral stem position were not compromised by the DSA. Complications included two Vancouver B2 periprosthetic fractures in the DSA group, of which there was one surgical-related fracture and one fracture after a traffic accident. Complications in the MPA group included one periprosthetic fracture, two hip dislocations, and one ischial neuropathy. No infections or thromboembolic events were observed. The 1-year complication rate was not different between the MPA and DSA groups (P = 0.40). CONCLUSION: The DSA can be safely introduced as no learning curve in the prosthesis position or the complication rate was found.

Does surgeon volume influence the outcome after hip hemiarthroplasty for displaced femoral neck fractures; early outcome, complications, and survival of 752 cases.

INTRODUCTION: Surgeon volume of hip arthroplasties is of importance with regard to complication and revision rates in total hip arthroplasty. For hip hemiarthroplasty, the effect of surgeon volume on outcome is far less studied. We analyzed the outcome of hip hemiarthroplasties performed by orthopedic surgeons in a retrospective cohort in different volume categories, focusing on early survival of the prosthesis and complications. METHODS: Between March 2009 and January 2014, 752 hemiarthroplasties were performed for intracapsular femoral neck fracture by 27 orthopedic surgeons in a large Dutch teaching hospital. Surgeons were divided into four groups, a resident group and three groups based on the number of total hip arthroplasties and hemiarthroplasties performed per year: a low-volume (< 10 arthroplasties per year), moderate-volume (10-35 arthroplasties per year), and high-volume groups (> 35 arthroplasties per year). Outcome measures were stem survival using a competing risk analysis, complication rates, and mortality. Chi-square tests were used to compare complication rates and mortality between groups. RESULTS: Patients were followed for a minimum of 2 years or until revision or death. Overall 60% of the patients included had died at time of follow-up. We found comparable stem survival rates in the low-volume group (n = 48), moderate-volume group (n = 201), high-volume group (n = 446), and resident group (n = 57). There were no significant differences between the groups with regard to dislocation rate, incidence of periprosthetic fracture, infection, and mortality. CONCLUSION: Surgeon volume and experience did not influence early outcome and complication rates in hip hemiarthroplasty. Hemiarthroplasty can safely be performed by both experienced hip surgeons and low-volume surgeons.

The Accolade TMZF stem fulfils the demands of modern stem design: Minimum 5-year survival in a cohort of 937 patients.

PURPOSE: Modern hip stem design includes a prosthesis that has a predictable outcome in all total hip arthroplasty (THA) patients, regardless of approach, surgeon or patient characteristics. Introduction without a learning curve and, in cases of problems, the possibility for a simple revision are other prerequisites. The purpose of this study is to evaluate whether the Accolade TMZF stem (Stryker Orthopedics, Mahwah, New Jersey, USA) is suitable to fulfil these demands. We report our mid-term survival of the Accolade TMZF hip stem in all patients from the first implantation at our institute. METHODS: From the start of using the Accolade TMZF stem (March 2009) until February 2011, 937 THA were performed by 12 surgeons using a posterolateral or anterolateral approach. Survival of the stem was calculated using Kaplan-Meier analysis. Effect of approach, patient age and comorbidity were analysed with a Cox proportional hazards' model. The learning effect was determined by comparing the number of revisions in the surgeons' first 20 THAs with their next 30 THAs and the subsequent THAs. RESULTS: At 5 years, cumulative stem survival was 97.9% based on revisions for all reasons and 98.8% with aseptic loosening as endpoint. We found no effect of surgical approach, patient age or comorbidity on stem survival. No learning effect was found. CONCLUSION: The Accolade TMZF stem fulfilled the demands of modern stem design.

Sport advice given by Dutch orthopaedic surgeons to patients after a total hip arthroplasty or total knee arthroplasty.

BACKGROUND: The advice given to patients in the Netherlands regarding sport activities after total hip arthroplasty or total knee arthroplasty (THA/TKA) is currently based on the opinion of the individual orthopaedic surgeon. AIM: To give an overview of the sport advice given by Dutch orthopaedic surgeons and to examine whether surgeons are familiar with the Dutch health-enhancing physical activity (PA) recommendations (NNGB). METHODS: 472 surgeons were selected to fill in a questionnaire regarding 40 sport activities for four patient age groups (in years): 1) THA<65, 2) THA>65, 3) TKA<65 4) TKA>65. Surgeons were also asked if they discuss the role of PA postoperatively and about their knowledge and application of the NNGB. RESULTS: There was consensus on 29 sport activities for the THA<65 group and 30 activities for the THA>65 group. In the TKA<65 group there was consensus for 33 sports activities and in the TKA>65 group for 32 activities. Amongst orthopaedic surgeons performing THAs and TKAs, respectively 77% and 79% discussed the role of PA postoperatively with their patients, and a total of 34% and 41% were familiar with the NNGB, with 33% and 34% of them giving NNGB-based advice. CONCLUSION: Results can be used to recommend sport activities after THA/TKA. Although the majority of orthopaedic surgeons discuss the role of PA postoperatively with their patients, familiarity with health-enhancing PA recommendations is lacking.

Midterm survival analysis of a cemented dual-mobility cup combined with bone impaction grafting in 102 revision hip arthroplasties.

INTRODUCTION: Revision hip arthroplasty is associated with higher dislocation rates than primary hip arthroplasty. A dual-mobility cup (DMC) can reduce this risk. Another problem is destruction of the acetabulum, induced by aseptic loosening of the prosthesis. Bone impaction grafting (BIG) can be used to reconstruct these defects, but is usually performed with cemented all polyethylene cups. The purpose of this study is to evaluate midterm cup survival and dislocation rate for the combination of BIG and DMC. METHODS: Between 2007 and 2013, 96 patients received 102 DMCs combined with BIG of the acetabulum during revision surgery. These data were first compared with a control group, consisting of 59 cases from the same hospital receiving a cemented all polyethylene cup combined with BIG. In addition, the control group was expanded with 41 cases operated on in 2007 in 'an orthopaedic centre of excellence', resulting in a 'combined control group' of 100 patients. Log-rank tests and chi-square tests were used to compare survival and dislocation rates, respectively. RESULTS: Cumulative survival of the DMC was 95.8% (range 3 months-7 years). This was comparable to the survival in the control groups (96.5% and 94.7%). The dislocation rate of 2.9% (3/102) in the dual-mobility group was lower (p = 0.02) compared to the dislocation rate of 11.8% (7/59) in the control group, but not (p = 0.12) compared to 8% in the combined control group (8/100). CONCLUSIONS: This study shows that combining a DMC with BIG does not compromise outcome in terms of midterm survival of the cup.

Comparison of gait in patients following a computer-navigated minimally invasive anterior approach and a conventional posterolateral approach for total hip arthroplasty: a randomized controlled trial.

Minimally invasive total hip arthroplasty (MIS THA) aims at minimizing damage to muscles and tendons to accelerate postoperative recovery. Computer navigation allows a precise prosthesis alignment without complete visualization of the bony landmarks during MIS THA. A randomized controlled trial (RCT) was conducted to determine the effectiveness of a computer-navigated MIS anterior approach for THA compared to a conventional posterolateral THA technique on the restoration of physical functioning during recovery following surgery. Thirty-five patients underwent computer-navigated MIS THA via the anterior approach, and 40 patients underwent conventional THA using the conventional posterolateral approach. Gait analysis was performed preoperatively, 6 weeks, and 3 and 6 months postoperatively using a body-fixed-sensor based gait analysis system. Walking speed, step length, cadence, and frontal plane angular movements of the pelvis and thorax were assessed. The same data were obtained from 30 healthy subjects. No differences were found in the recovery of spatiotemporal parameters or in angular movements of the pelvis and thorax following the computer-navigated MIS anterior approach or the conventional posterolateral approach. Although gait improved after surgery, small differences in several spatiotemporal parameters and angular movements of the trunk remained at 6 months postoperatively between both patient groups and healthy subjects.

Minimally invasive total hip and knee arthroplasty-implications for the elderly patient.

Overall, it can be concluded that because of the aging society, an increasing number of elderly people will be undergoing total joint arthroplasty. These elderly patients have an increased risk for serious complications after primary THA or TKA. However, the overall complication rates remain low. The use of MIS total joint arthroplasty is also increasing, although its risks and benefits are still an ongoing issue of debate in the orthopedic community. MIS total joint arthroplasty aims at decreasing the surgical incision and minimizing damage to the underlying soft tissue to accelerate postoperative recovery and an earlier return to normal function. A critical look at the literature on MIS shows that the term minimally invasive is often used for a conventional total joint arthroplasty performed through a smaller skin incision. Research has shown promising results of using MIS in elderly patients; it seems that compared with younger patients, elderly patients benefit more from a minimally invasive approach.

Subjects with hip osteoarthritis show distinctive patterns of trunk movements during gait-a body-fixed-sensor based analysis.

BACKGROUND: Compensatory trunk movements during gait, such as a Duchenne limp, are observed frequently in subjects with osteoarthritis of the hip, yet angular trunk movements are seldom included in clinical gait assessments. Hence, the objective of this study was to quantify compensatory trunk movements during gait in subjects with hip osteoarthritis, outside a gait laboratory, using a body-fixed-sensor based gait analysis. Frontal plane angular movements of the pelvis and thorax and spatiotemporal parameters of persons who showed a Duchenne limp during gait were compared to healthy subjects and persons without a Duchenne limp. METHODS: A Body-fixed-sensor based gait analysis approach was used. Two body-fixed sensors were positioned at the dorsal side of the pelvis and on the upper thorax. Peak-to-peak frontal plane range of motion (ROM) and spatiotemporal parameters (walking speed, step length and cadence) of persons with a Duchenne limp during gait were compared to healthy subjects and persons without a Duchenne limp. Participants were instructed to walk at a self-selected low, preferred and high speed along a hospital corridor. Generalized estimating equations (GEE) analyses were used to assess group differences between persons with a Duchenne limp, without a Duchenne limp and healthy subjects. RESULTS: Persons with a Duchenne limp showed a significantly larger thoracic ROM during walking compared to healthy subjects and to persons without a Duchenne limp. In both groups of persons with hip osteoarthritis, pelvic ROM was lower than in healthy subjects. This difference however only reached significance in persons without a Duchenne limp. The ratio of thoracic ROM relative to pelvic ROM revealed distinct differences in trunk movement patterns. Persons with hip osteoarthritis walked at a significantly lower speed compared to healthy subjects. No differences in step length and cadence were found between patients and healthy subjects, after correction for differences in walking speed. CONCLUSIONS: Distinctive patterns of frontal plane angular trunk movements during gait could be objectively quantified in healthy subjects and in persons with hip osteoarthritis using a body-fixed-sensor based gait analysis approach. Therefore, frontal plane angular trunk movements should be included in clinical gait assessments of persons with hip osteoarthritis.

Changes in body weight after total hip arthroplasty: short-term and long-term effects.

BACKGROUND: Elevated body weight is associated with hip osteoarthritis (OA) and subsequently with total hip arthroplasty (THA). Patients with hip OA who are overweight often mention their restricted mobility as a factor that thwarts their attempts to be physically active and lose weight. There is some evidence that THA increases physical activity, but none for losing body weight after THA. OBJECTIVE: The purpose of this study was to analyze the short-term (1-year) and long-term (4.5-year) effects of a THA on body weight. DESIGN: This was an observational, multicenter cohort study. METHODS: For the short-term effect, all patients (N=618) were analyzed; for the long-term effect, a random subgroup (n=100) was analyzed. Preoperative and postoperative body weight and height were self-reported. Patients were categorized according to their preoperative body mass index (BMI <25 kg/m(2)=normal weight, 25-30 kg/m(2)=overweight, >30 kg/m(2)=obese). Clinical relevancy was set at a minimum of 5% weight loss compared with baseline. RESULTS: The mean age of the study group was 70 years (SD=8), 74% were women, and mean preoperative body mass was 79 kg (SD=14). One year after THA, a significant decrease in body weight of 1% and 3.4% occurred for the overweight and obese BMI categories, respectively. After 4.5 years, a significant decrease in body weight of 6.4% occurred for the obese BMI category. LIMITATIONS: Height and weight-and thus BMI-were self-reported. CONCLUSION: Patients in the overweight and obese groups showed a decrease, albeit not clinically relevant, in body weight after 1 year. After 4.5 years, a decrease that was relevant clinically was observed in the patients who were obese. It can be concluded that no clinically relevant reduction of weight occurred after THA, except in the long term for patients who were obese.

The influence of overweight/obesity on patient-perceived physical functioning and health-related quality of life after primary total hip arthroplasty.

BACKGROUND: Overweight/obesity in patients after total hip arthroplasty (THA) is a growing problem and is associated with postoperative complications and a negative effect on functional outcome. The objective of this study is to determine to what extent overweight/obesity is associated with physical functioning and health-related quality of life 1 year after primary THA. METHODS: A retrospective analysis of prospectively collected data from 653 patients who had undergone a primary THA was conducted. Physical functioning, health-related quality of life, body mass index (BMI), comorbidity, and postoperative complications were assessed by means of a questionnaire and from medical records. To determine to what extent overweight/obesity is associated with physical functioning and health-related quality of life after THA, a structural equation model (SEM) analysis was conducted. RESULTS: The association of BMI corrected for age, gender, complications, and comorbidity with physical functioning is -0.63. This means that an increase in 1 kg/m2 BMI leads to a reduction of 0.63 points in the physical functioning score as measured with the Western Ontario and McMaster Universities Osteoarthritis Index (100-point scale). The prevalence of complications or comorbidity leads to a reduction of, respectively, 5.63 and 7.25 (one or two comorbidities) and 14.50 points in the case of more than two comorbidities on the physical functioning score. The same pattern is observed for health-related quality of life. CONCLUSIONS: The influence of overweight/obesity on physical functioning and health-related quality of life is low. The impact of complications and comorbidity is considerable. Refusing a patient a THA solely on the basis of overweight or obesity does not seem justified.

Compensatory trunk movements in patients with hip osteoarthritis: accuracy and reproducibility of a body-fixed sensor-based assessment.

This study examined the accuracy and reproducibility of a body-fixed sensor-based assessment for quantifying frontal plane angular movements of the (upper) thorax and pelvis of patients with hip osteoarthritis at different walking speeds. To evaluate accuracy, the angular movements of sensors attached to the thorax and pelvis of three patients were compared with results based on an optical motion analysis system. Accuracy was high, with small and consistent mean differences (<1.0 degree) and corresponding standard deviations (<1.3 degrees) between optical motion analysis system and body-fixed sensor data. To evaluate reproducibility, angular trunk movements were assessed twice in 15 patients. Reproducibility was high (intraclass correlation coefficients ranged from 0.86 to 0.97), and the values of the mean differences between the test and retest were small, with the 95% confidence interval containing zero. This body-fixed sensor-based assessment is an accurate and reproducible method for quantifying frontal plane compensatory trunk movements during gait of patients with hip osteoarthritis at different walking speeds.

Physical activity behavior of patients 1 year after primary total hip arthroplasty: a prospective multicenter cohort study.

BACKGROUND: Besides the important beneficial effects of regular physical activity on general health, some of the musculoskeletal effects of physical activity are of particular interest for older adults after total hip arthroplasty (THA). However, research on physical activity behavior of patients after THA is scarce. OBJECTIVE: The purpose of this study was to gain insight into the physical activity behavior and fulfillment of guidelines for health-enhancing physical activity of patients 1 year after THA. Design This was a prospective multicenter cohort study. METHODS: To determine level of physical activity, 653 participants (response rate=77%) completed the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH). Comparisons were made between participants in 2 age groups (≤75 and >75 years). Determinants of physical activity behavior were assessed. RESULTS: The participants were physically active a mean of 1,468 minutes per week. Most time was spent in household and leisure activities. Younger participants were physically more active than older participants. A lower body mass index was predictive of a higher level of physical activity. Participants adhered to the guidelines of health-enhancing physical activity in 67% of cases. The guidelines were met more often by younger participants, male participants, and those without problems in the lower extremities. Limitations A nonresponse analysis was not conducted; thus, there might have been a selection bias. Use of a self-administered recall questionnaire to assess physical activity behavior may have been subject to memory and recall skill limitations of the participants, and patients tend to overestimate their physical activity level. CONCLUSIONS: This study gives detailed insight into the physical activity of patients 1 year after primary THA. As among the general population, a considerable number of patients were found to be insufficiently physically active.

Minimally invasive and computer-navigated total hip arthroplasty: a qualitative and systematic review of the literature.

BACKGROUND: Both minimally invasive surgery (MIS) and computer-assisted surgery (CAS) for total hip arthroplasty (THA) have gained popularity in recent years. We conducted a qualitative and systematic review to assess the effectiveness of MIS, CAS and computer-assisted MIS for THA. METHODS: An extensive computerised literature search of PubMed, Medline, Embase and OVIDSP was conducted. Both randomised clinical trials and controlled clinical trials on the effectiveness of MIS, CAS and computer-assisted MIS for THA were included. Methodological quality was independently assessed by two reviewers. Effect estimates were calculated and a best-evidence synthesis was performed. RESULTS: Four high-quality and 14 medium-quality studies with MIS THA as study contrast, and three high-quality and four medium-quality studies with CAS THA as study contrast were included. No studies with computer-assisted MIS for THA as study contrast were identified. Strong evidence was found for a decrease in operative time and intraoperative blood loss for MIS THA, with no difference in complication rates and risk for acetabular outliers. Strong evidence exists that there is no difference in physical functioning, measured either by questionnaires or by gait analysis. Moderate evidence was found for a shorter length of hospital stay after MIS THA. Conflicting evidence was found for a positive effect of MIS THA on pain in the early postoperative period, but that effect diminished after three months postoperatively. Strong evidence was found for an increase in operative time for CAS THA, and limited evidence was found for a decrease in intraoperative blood loss. Furthermore, strong evidence was found for no difference in complication rates, as well as for a significantly lower risk for acetabular outliers. CONCLUSIONS: The results indicate that MIS THA is a safe surgical procedure, without increases in operative time, blood loss, operative complication rates and component malposition rates. However, the beneficial effect of MIS THA on functional recovery has to be proven. The results also indicate that CAS THA, though resulting in an increase in operative time, may have a positive effect on operative blood loss and operative complication rates. More importantly, the use of CAS results in better positioning of acetabular component of the prosthesis.

People who undergo revision arthroplasty report more limitations but no decrease in physical activity compared with primary total hip arthroplasty: an observational study.

QUESTION: Do people who have had revision arthroplasty report more limitations and less physical activity than those after primary total hip arthroplasty? Can degree of limitation and physical activity be predicted by revision arthroplasty, after adjustment for age, gender, and Charnley classification? DESIGN: Cross-sectional observational study. PARTICIPANTS: 371 people after primary and 134 after revision total hip arthroplasty. OUTCOME MEASURES: Limitations were measured using the Dutch-language version of the WOMAC questionnaire and amount and intensity of physical activity was measured using the SQUASH questionnaire. RESULTS: The revision arthroplasty group reported 12% (95% CI 7 to 17) more limitations than the primary total hip arthroplasty group. They also reported 394 min/wk (95% CI 88 to 701) less physical activity and 1153 min/wk (95% CI 66 to 2241) less intensity of physical activity than the primary total hip arthroplasty group. Having had a revision arthroplasty predicted limitations regardless of whether the prediction was adjusted for age, gender, or Charnley group (B -12.1, 95% CI -17.2 to -7.0). However, having had a revision arthroplasty did not predict either amount (B -121.2, 95% CI -408.0 to 165.7) or intensity (B -912.8, 95% CI -1989.1 to 163.6) of physical activity when the prediction was adjusted for age, gender, and Charnley group. CONCLUSION: People reported more limitations after revision arthroplasty than after primary total hip arthroplasty. However, people after revision arthroplasty appeared to be equally physically active as those after primary total hip arthroplasty after adjusting for age, gender, and Charnley group.

Reliability and validity of the short questionnaire to assess health-enhancing physical activity (SQUASH) in patients after total hip arthroplasty.

BACKGROUND: Despite recognized benefits of regular physical activity on musculoskeletal fitness as well as general health, little is known about the physical activity behavior of patients after Total Hip Arthroplasty (THA). So far, no physical activity questionnaire has been validated in this category of patients. As the Short Questionnaire to Assess Health-enhancing physical activity (SQUASH) has been shown to be a fairly reliable and valid tool to gauge the physical activity behavior of the general Dutch adult population, we measured the reliability and relative validity of this tool in patients after THA. METHODS: 44 patients (17 men and 27 women, mean age 71 +/- 8 years) completed the SQUASH twice with an in-between period of 2 to 6 weeks (mean 3.7). Reliability was determined by calculating the Spearman correlation coefficient between the activity scores of the separate questions as well as the total activity scores from both administrations. Additionally, a Bland & Altman analysis was performed for the total activity scores. Relative validity was determined using the Actigraphaccelerometer, worn by 39 patients (15 men and 24 women, mean age 70 +/- 8 years) for a 2-week period following the second questionnaire, as a criterion measure. RESULTS: Spearman's correlation coefficient for overall reliability was 0.57. It varied between 0.45 and 0.90 for the separate questions. No systematic biases between readings were found. The Spearman correlation between Actigraph readings and total activity score was 0.67. It was 0.56 for total minutes of activity, 0.20 for time spent in light intensity activity, 0.40 for moderate activity and 0.35 for vigorous activity. Systematic bias was found between the SQUASH and the Actigraph. CONCLUSION: The SQUASH can be considered to be a fairly reliable tool to assess the physical activity behavior of patients after THA. Validity was found to be comparable with those of other questionnaires, and as it is short and easy to fill in, it may prove to be a useful tool to assess physical activity in this particular subset of the population. However, the considerable systematic bias found in this study illustrates the need for further analysis of the validity of the SQUASH.

Habitual physical activity behavior of patients after primary total hip arthroplasty.

BACKGROUND AND PURPOSE: Despite recognized health benefits of physical activity, little is known about the habitual physical activity behavior of patients after total hip arthroplasty (THA). The purpose of this study was to analyze this behavior and the fulfillment of guidelines for health-enhancing physical activity of these patients compared with a normative population. SUBJECTS AND METHODS: The participants were 273 patients who had undergone a primary THA (minimum of 1 year postoperatively). Comparisons were made between this group and 273 age- and sex-matched individuals from a normative population. Comparisons also were made between participants with THA under 65 years of age and those 65 years of age and older and among participants with THA in different Charnley classes. Level of physical activity was assessed with the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH). RESULTS: No significant differences in total amount of physical activity or time spent in different categories of physical activity were found between the THA group and the normative group. Participants with THA spent significantly more minutes in activities of moderate intensity compared with the normative group. Participants with THA who were under 65 years of age were significantly more active than older participants with THA. Charnley class had significant effects on time spent at work, time spent in moderate-intensity activities, and total amount of activity, with the least activity performed by participants in Charnley class C. The guidelines were met by 51.2% of the participants with THA and 48.8% of the normative population. Female participants met the guidelines less frequently than male participants in both the combined groups (odds ratio=0.50, 95% confidence interval=0.35-0.72, P<.001) and the THA group (odds ratio=0.48, 95% confidence interval=0.28-0.80, P=.001). DISCUSSION AND CONCLUSION: The results suggest that patients after THA are at least as physically active as a normative population. Nevertheless, a large percentage of these patients do not meet the guidelines; therefore, they need to be stimulated to become more physically active.

Predictive value of the Western Ontario and McMaster Universities Osteoarthritis Index for the amount of physical activity after total hip arthroplasty.

BACKGROUND AND PURPOSE: Despite the recognized health benefits of physical activity, little is known about the amount of physical activity that patients perform after total hip arthroplasty (THA). To this end, the ability of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) to predict the amount of physical activity that patients with a THA perform, as measured by the Short Questionnaire to Assess Health-Enhancing Physical Activity (SQUASH), was determined. SUBJECTS AND METHODS: Three hundred sixty-four patients who had a THA returned questionnaires. Pearson correlation coefficients were calculated between scores on the WOMAC and SQUASH. Binary logistic regression modeling was used to determine the extent to which the WOMAC score could predict that patients would meet national and international guidelines for health-enhancing physical activity. RESULTS: Scores on the WOMAC and SQUASH showed a significant, but low, correlation (r=.14-.24). Although the WOMAC score was a significant predictor for meeting national and international guidelines for physical activity, the odds ratio was low (1.022, 95% confidence interval=1.012-1.033) and only 6.9% of the variance could be explained (Nagelkerke r(2)=.069). DISCUSSION AND CONCLUSION: The results suggest that the WOMAC is not suitable for predicting the amount of physical activity after THA, requiring the use of an additional outcome measure.

Physical activity behavior after total hip arthroplasty (THA): a prediction based on patient characteristics.

OBJECTIVE: To determine to what extent aspects of patient characteristics (age, gender, family status, education and comorbidity) are predictive for the level of physical activity of persons with a total hip arthroplasty (THA). METHODS: A cross-sectional study including 372 patients. Demographics, comorbidity and physical activity behavior were assessed by means of a questionnaire and from medical records. Linear regression analysis was used to determine to what extent patient characteristics are predictive of level of physical activity. Binary logistic regression modeling was used to determine the extent to which patient characteristics are predictive in meeting international guidelines on health-enhancing physical activity. RESULTS: Age, education and family status significantly predict level of physical activity (R(2)=0.19). Only gender significantly predicts meeting international guidelines on health-enhancing physical activity (OR=2.06, 95% CI 1.20-3.54). CONCLUSION: Patients at risk can be identified by means of patient characteristics. Increasing age, lower education and living alone are associated with a physically inactive lifestyle. PRACTICE IMPLICATIONS: Health care workers involved in the treatment of THA patients should lay an emphasis on the beneficial aspects of physical activity.