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Background and purpose

A questionnaire was introduced by the New Zealand Arthroplasty Registry for use when evaluating the outcome of total ankle replacement surgery. We evaluated the reliability, validity, and responsiveness of the modified Swedish version of the questionnaire (SEFAS) in patients with osteoarthritis or inflammatory arthritis before and/or after their ankle was replaced or fused.

Patients and methods

The questionnaire was translated into Swedish and cross-culturally adapted according to a standardized procedure. It was sent to 135 patients with ankle arthritis who were scheduled for or had undergone surgery, together with the foot and ankle outcome score (FAOS), the short form 36 (SF-36) score, and the EuroQol (EQ-5D) score. Construct validity was evaluated with Spearman’s correlation coefficient when comparing SEFAS with FAOS, SF-36, and EQ-5D, content validity by calculating floor and ceiling effects, test-retest reliability with intraclass correlation coefficient (ICC), internal consistency with Cronbach’s alpha (n = 62), agreement by Bland-Altman plot, and responsiveness by effect size and standardized response mean (n = 37).

Results

For construct validity, we correlated SEFAS with the other scores and 70% or more of our predefined hypotheses concerning correlations could be confirmed. There were no floor or ceiling effects. ICC was 0.92 (CI 95%: 0.88–0.95), Cronbach’s alpha 0.96, effect size was 1.44, and the standardized response mean was 1.00.

Interpretation

SEFAS is a self-reported foot and ankle score with good validity, reliability and responsiveness, indicating that the score can be used to evaluate patients with osteoarthritis or inflammatory arthritis of the ankle and outcome of surgery.

Background

The aim of the study was to evaluate if physical functions usually associated with a younger population were of importance for an older population, and to construct an outcome measure for hip osteoarthritis with improved responsiveness compared to the Western Ontario McMaster osteoarthritis score (WOMAC LK 3.0).

Methods

A 40 item questionnaire (hip disability and osteoarthritis outcome score, HOOS) was constructed to assess patient-relevant outcomes in five separate subscales (pain, symptoms, activity of daily living, sport and recreation function and hip related quality of life). The HOOS contains all WOMAC LK 3.0 questions in unchanged form. The HOOS was distributed to 90 patients with primary hip osteoarthritis (mean age 71.5, range 49–85, 41 females) assigned for total hip replacement for osteoarthritis preoperatively and at six months follow-up.

Results

The HOOS met set criteria of validity and responsiveness. It was more responsive than WOMAC regarding the subscales pain (SRM 2.11 vs. 1.83) and other symptoms (SRM 1.83 vs. 1.28). The responsiveness (SRM) for the two added subscales sport and recreation and quality of life were 1.29 and 1.65, respectively. Patients ≤ 66 years of age (range 49–66) reported higher responsiveness in all five subscales than patients >66 years of age (range 67–85) (Pain SRM 2.60 vs. 1.97, other symptoms SRM 3.0 vs. 1.60, activity of daily living SRM 2.51 vs. 1.52, sport and recreation function SRM 1.53 vs. 1.21 and hip related quality of life SRM 1.95 vs. 1.57).

Conclusion

The HOOS 2.0 appears to be useful for the evaluation of patient-relevant outcome after THR and is more responsive than the WOMAC LK 3.0. The added subscales sport and recreation function and hip related quality of life were highly responsive for this group of patients, with the responsiveness being highest for those younger than 66.

Objective

Expectations of higher activity levels associated with hip resurfacing arthroplasty (HRA) may be driving better outcomes in this group compared to total hip arthroplasty (THA). Previous studies evaluated expectations before consulting with the surgeon, although these expectations are likely unrealistic and would change after the consultation. We compared HRA and THA patient expectation after consultation with the surgeon.

Methods

In a prospective registry setting, patients awaiting HRA were matched to THA patients on age, sex, and preoperative Lower Extremity Activity Scale score (range 1–18, 18 highest activity level). Patients completed a validated 18-item expectations survey preoperatively. Mean overall expectations scores were first compared. Exploratory factor analysis (EFA) was then performed to determine if grouping of individual expectations items represented meaningfully different underlying factors in the 2 groups.

Results

We matched 123 pairs. Mean expectation scores were similar (HRA: 85.2±15.5, THA: 87.3±13.9; p-value=0.249). EFA showed that HRA and THA patients shared in common expectations of 1) pain relief and improvement in daily activities (9 items) and 2) eliminating pain medications, the need for cane and improving sexual activity (3 items). THA patients perceived the remaining 6 items as an overall third expectation of participation in higher-level activities. However, HRA patients perceived a fourth expectation of normal range of motion (2 items) independent of the other higher-level activities (4 items).

Conclusion

Even after consulting with a surgeon, patients’ expectations differed between HRA and THA patients regarding higher-level activities. More counseling of patients seeking hip arthroplasty is thus needed.

There is currently no German version of the Oxford hip score. Therefore we sought to cross-culturally adapt and validate the Oxford hip score for use with German-speaking patients (OHS-D) with osteoarthritis of the hip using a forward-backward translation procedure. We then assessed the new score in 105 consecutive patients (mean age, 63.4 years; 48 women) undergoing THA. We specifically determined: the number of fully completed questionnaires, reliability, concurrent validity by correlation with the WOMAC, Harris hip score, and SF-12, and distribution of floor and ceiling effects. We received 96.6% fully completed questionnaires. An intraclass correlation coefficient of 0.90 and Cronbach’s alpha of 0.87 suggested the OHS-D was reliable. Correlation coefficients between the OHS-D and the WOMAC total score, pain subscale, stiffness subscale, and physical function subscale were 0.82, 0.70, 0.68, and 0.82, respectively. OHS-D correlated with the Harris hip score (r = 0.63) and the physical component scale of the SF-12 (r = 0.58). We observed no ceiling or floor effects. The OHS-D appeared a reliable and valid measurement tool for assessing pain and disability with German-speaking patients with hip osteoarthritis.

Level of Evidence: Level I, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Background

Primary total hip arthroplasty (THA) is an effective treatment for hip osteoarthritis, assessed by whatever distribution-based measures of responsiveness. Yet, the group level evaluation has provided very little evidence contributes to our understanding of the large variation of treatment outcome. The objective is to develop criteria that classify individual treatment health related quality of life (HRQOL) outcome after primary THA, adjusted by preoperative scores.

Methods

We prospectively measured 147 patients' disease specific HRQOL on the date of consultation and 12 months post operation by Western Ontario McMaster Universities Osteoarthritis Index (WOMAC). Regression models were used to determine the "expected" outcome for a certain individual baseline score. The ceiling effect of WOMAC measurement is addressed by implementing a left-censoring method.

Results

The classification criteria are chosen to be the lower boundary of the 95% confidence interval (CI) of the estimated median from the regression. The robustness of the classification criteria was demonstrated using the Monte-Carlo simulation.

Conclusion

The classification criteria are robust and can be applied in general orthopaedic research when the sample size is reasonable large (over 500).

Introduction

There is no current consensus on the most appropriate prosthesis for treating symptomatic osteoarthritis (OA) of the hip in young, active patients. Modern metal on metal hip resurfacing arthroplasty (HR) has gained popularity as it is theoretically more stable, bone conserving and easier to revise than total hip arthroplasty. Early results of metal on metal resurfacing have been encouraging. We have compared two well matched cohorts of patients with regard to function, pain relief and patient satisfaction.

Methods

This prospective study compares 2 cohorts of young, active patients treated with hip resurfacing (137 patients, 141 hips) and custom uncemented (CADCAM) stems (134 patients, 141 hips). All procedures were performed by a single surgeon. Outcome measures included Oxford, WOMAC and Harris hip scores as well as an activity score. Statistical analysis was performed using the unpaired student's t-test.

Results

One hundred and thirty four and 137 patients were included in the hip replacement and resurfacing groups respectively. The mean age of these patients was 54.6 years. The mean duration of follow up for the hip resurfacing group was 19.2 months compared to 13.4 months for the total hip replacement group.

Pre operative oxford, Harris and WOMAC scores in the THA group were 41.1, 46.4 and 50.9 respectively while the post operative scores were 14.8, 95.8 and 5.0. In the HR group, pre- operative scores were 37.0, 54.1 and 45.9 respectively compared to 15.0, 96.8 and 6.1 post operatively. The degree of improvement was similar in both groups.

Conclusion

There was no significant clinical difference between the patients treated with hip resurfacing and total hip arthroplasty in the short term.

Background and purpose

There has been a limited amount of research on survival of total hip arthroplasties (THAs) in rheumatoid arthritis (RA). We therefore performed a population-based, nationwide study to compare the survival of primary THAs in RA patients and in osteoarthritis (OA) patients. We also wanted to identify predictors of THA failure in RA patients.

Methods

Using the Danish Hip Arthroplasty Registry, we identified 1,661 primary THAs in RA patients and 64,858 in OA patients, all of which were inserted between 1995 and 2008. The follow-up period was up to 14 years for both groups.

Results

Regarding overall THA survival, the adjusted RR for RA patients compared to OA patients was 0.81 (95% CI: 0.65–1.01). We found no difference in survival of cups between primary THAs in RA and OA patients. In contrast, there was better overall survival of stems in RA patients than in OA patients, both regarding revision due to aseptic loosening (adjusted RR = 0.58; 95% CI: 0.34–0.99) and for any reason (adjusted RR = 0.63; 95% CI: 0.45–0.88). In RA patients, males had a higher risk of revision than females concerning aseptic loosening of the stem, any revision of the stem, and any revision of both components.

Interpretation

The overall survival of primary THAs in RA patients is similar to THA survival in OA patients. Stem survival appeared to be better in RA patients, while survival of the total THA concept did not show any statistically significant differences between the two groups. In RA patients, males appear to have a greater risk of revision than females.

Objectives

The Displaced Femoral (neck fracture) Arthroplasty Consortium for Treatment and Outcomes (DFACTO) study compared total hip arthroplasty (THA) to hemiarthroplasty in the treatment of displaced femoral neck fractures.

Design

This study was designed as a prospective, randomized clinical trial.

Setting

The study was conducted in five US academic and private medical centers.

Patients

Patients were composed of independent, mentally competent individuals, >50 years old who suffered a displaced femoral neck fracture without existing arthritis at the hip. Forty-one patients were enrolled.

Main outcome measures

Functional outcomes and quality of life were assessed at 6 and 12 months post-fracture using the SF-36, Western Ontario and McMaster University Osteoarthritis Index (WOMAC), the Harris Hip Score, and the Timed “Up & Go” Test (TUG test).

Results

Groups were equivalent at baseline in terms of age, comorbid conditions, and functional status. At 6 months, there were no significant differences between the groups using the outcome measures or overall rates of complications. There was one dislocation in the THA group (5.8% of patients). At 12 months, the THA group reported significantly less pain (53.2 ± 10.2) than the hemiarthroplasty group (42.4 ± 11.5) using the SF-36 (p = 0.02). Using the TUG Test, we observed a greater proportion of THA patients remain functionally independent 1 year after surgery compared the hemiarthroplasty group (p = 0.08, controlling for age and sex).

Conclusions

These differences in pain and functional outcomes suggest THA is a viable treatment option for the active elderly displaced femoral neck fracture population.

Objective To compare characteristics of patients and outcomes after elective surgery in independent sector treatment centres (ISTCs) and NHS providers.

Design Follow-up study with outcomes reported by patients three to six months after surgery.

Setting 25 ISTCs and 72 NHS providers in England.

Population Consecutive patients undergoing hip or knee replacement (5671 in ISTCs and 14 292 in NHS), inguinal hernia repair (640 and 2023, respectively), or surgery for varicose veins (248 and 1336, respectively).

Main outcomes Symptoms and disability reported by patients (Oxford hip and knee scores on a 48 point scale; Aberdeen varicose vein questionnaire) and quality of life (EuroQol EQ-5D score).

Results Patients in ISTCs were healthier than those in NHS providers, had less severe preoperative symptoms, and were more affluent, though the differences were small. With adjustment, patients undergoing joint replacements in NHS providers had poorer outcomes: difference of −1.7 (95% confidence interval −2.5 to −0.9) on the Oxford hip score and −0.9 (−1.6 to −0.2) on the Oxford knee score. They more often reported complications: odds ratio 1.3 (95% confidence interval 1.1 to 1.5) for hip and 1.4 (1.2 to 1.6) for knee. There were no significant differences in outcomes after surgery for hernia or varicose veins, except that NHS patients more often reported poor results after hernia repair (1.4, 1.0 to 1.9) and additional surgery after varicose vein surgery (2.8, 1.2 to 6.8).

Conclusion Patients undergoing surgery in ISTCs were slightly healthier and had less severe conditions than those undergoing surgery in NHS providers. Some outcomes were better in ISTCs, but differences were small compared with the impact ISTCs could have on the provision of elective services.

Background and purpose

There has been a limited amount of research on risk factors for revision due to infection following total hip arthroplasty (THA), probably due to low absolute numbers of revisions. We therefore studied patient- and surgery-related risk factors for revision due to infection after primary THA in a population-based setting.

Materials and methods

Using the Danish Hip Arthroplasty Registry, we identified 80,756 primary THAs performed in Denmark between Jan 1, 1995 and Dec 31, 2008. We used Cox regression analysis to compute crude and adjusted relative risk (RR) of revision due to infection. Revision was defined as extraction or exchange of any component due to infection. The median follow-up time was 5 (0–14) years.

Results

597 primary THAs (0.7%) were revised due to infection. Males, patients with any co-morbidity, patients operated due to non-traumatic avascular femoral head necrosis, and patients with long duration of surgery had an increased RR of revision due to infection within the total follow-up time. A tendency of increased RR of revision was found for patients who had received cemented THA without antibiotic and hybrid THA relative to patients with cementless implants. Hip diagnosis and fixation technique were not associated with risk of revision due to infection within 1 year of surgery (short-term risk).

Interpretation

We identified several categories of THA patients who had a higher risk of revision due to infection. Further research is required to explain the mechanism underlying this increased risk. More attention should be paid by clinicians to infection prevention strategies in patients with THA, particularly those with increased risk.

Background Patients with hip osteoarthritis (OA) have muscular weakness, impaired balance, and limp. Deficits in the different limb muscles and their recovery courses are largely unknown, however. We hypothesized that there is persisting muscular weakness in lower limb muscles and an impaired balance and gait 2 years after THA.

Patients and methods 20 elderly patients with unilateral OA were assessed before, and 6 and 24 months after surgery for maximal voluntary isometric strength of hip and knee muscles and by gait analysis, postural stability, and clinical scores (HHS, SF-36, EuroQoL).

Results Hip muscles showed a remaining 6% weakness compared to the contralateral healthy limb 2 years after THA. Preoperatively and 6 months postoperatively, that deficit was 18% and 12%, respectively. Knee extensors fully recovered a preoperative 27% deficit after 2 years. Gait analysis demonstrated a shorter single stance phase for the OA limb compared to healthy limb preoperatively, that had already recovered at the 6-month follow-up. Balance of two-foot standing showed improvement in both sagittal and lateral sway after operation. All clinical scores improved.

Interpretation Muscle strength data demonstrated a slow but full recovery of muscles acting about the knee, but there was still a deficit in hip muscle strength 2 years after THA. Gait and balance recovered after the operation. To accelerate improvement in muscular strength after THA, postoperative training should probably be more intense and target hip abductors.

The Kaiser Permanente National Total Joint Replacement Registry (TJRR) is a national level database designed as a postmarket surveillance system for elective total hip and knee replacement. As of March 31, 2007, the TJRR recorded 16,945 primary total hip arthroplasties (THA), 2144 revisions (11.2%); and 30,815 total knee arthroplasties (TKA), 1794 revisions (5.5%). Statistically significant findings include: older age and higher American Society of Anesthesiology risk scores for revision THAs. Osteoarthritis is the most common diagnosis for THA and TKA, and aseptic loosening and instability are most common in revision THAs and TKAs. The TJRR has provided a mechanism for recalls, identified patients at risk for early revisions and changed practice by providing feedback to physicians.

Background

There is a lack of data on the long-term outcome of total hip arthroplasty procedures, as assessed by validated tools.

Methods

We conducted a follow-up study to evaluate the quality of life and functionality of 250 patients an average of 16 years (range: 11-23 years) after total hip arthroplasty using a validated assessment set including the SF-36 questionnaire, Harris Hip Score, WOMAC score, Functional Comorbidity Index, and a study specific questionnaire. Models of multiple stepwise linear and logistic regression analysis were constructed to evaluate the relationships between several explanatory variables and these functional outcomes.

Results

The SF-36 physical indexes of these patients compared negatively with the normative values but positively with the results obtained in untreated subjects with severe hip osteoarthritis. Similar results were detected for the Harris Hip Score and WOMAC score. There was a 96% rate of post-surgical satisfaction. Hip functionality and comorbidities were the most important determinants of physical measures on the SF-36.

Conclusions

Patients who had undergone total hip arthroplasty have impaired long-term self-reported physical quality of life and hip functionality but they still perform physically better than untreated patients with advanced hip osteoarthritis. However, the level of post-surgical satisfaction is high.

Objectives—To evaluate the performance of a patient assessed outcome measure, the Oxford Hip Score, in a national study of primary hip replacement surgery.

Design—A survey of patients' health status before undergoing primary hip replacement surgery and three months and one year after surgery.

Setting—143 hospitals in three NHS English regions.

Patients—7151 patients admitted for primary total hip replacement surgery over a period of 13 months from September 1996.

Main measures—For patients, Oxford Hip Score and satisfaction with hip replacement and, for surgeons, American Anesthiologists' Society (ASA) classification of physical status.

Results—The response rates to the postal questionnaire at three and 12 months follow up were 85.2% and 80.7%, respectively. Including all three administrations of the questionnaire, all except two items of the Oxford Hip Score were completed by 97% or more respondents and only one item at one administration appeared marginally to reduce the reliability of the score. The effect sizes for changes in the score from baseline to three months was 2.50 and to 12 months was 3.05. Patients rated by surgeons as being healthy preoperatively by the ASA classification were somewhat more likely to return a completed questionnaire at three months (79.4% versus 75.3%) and 12 months (72.4% versus 70.3%) than those rated as having poorer health.

Conclusions—Overall there was little evidence of difficulties for patients in completing the Oxford Hip Score or of unreliable data, except in relation to one questionnaire item. The instrument was very responsive to change over time and score changes for the Oxford Hip Score related well to patients' satisfaction with their surgery. The instrument is an appropriate measure in terms of validity, responsiveness, and feasibility for evaluating total hip replacement from the perspective of the patient.

Key Words: total hip replacement surgery; Oxford Hip Score; questionnaire; assessment

Background

The proportion of total hip arthroplasties (THAs) associated with corticosteroid use is uncertain, and the mechanisms of corticosteroid-induced osteonecrosis remain unknown. We sought to evaluate the clinical and radiographic outcomes, complications and satisfaction with THA among patients with corticosteroid-induced osteonecrosis.

Methods

We retrospectively assessed functional outcome at a minimum 1-year follow-up using the Western Ontario and MacMaster Universities Arthritis Index (WOMAC); Oxford Hip Score; Short Form (SF)-12; University of California, Los Angeles (UCLA) Activity; and patient satisfaction scores.

Results

We included 31 patients (35 hips). The average follow-up was 20 (range 12–55) months, and the average age at surgery was 47 (range 19–78) years. At follow-up, patients showed significant improvement in all 4 components of the WOMAC (means: function 84, stiffness 75, pain 86, global 84), Oxford-12 (mean 83) and SF-12 (means: mental 40 and physical 48) scores. However, there was no significant improvement in the UCLA Activity scores. Mean patient satisfaction scores were good for pain relief (86), function (80), recreation (77.5) and overall results of surgery (86). Radiographic review at follow-up showed that all components were well fixed with no evidence of loosening. The complication rate was high (17%), with 6 complications in 5 patients (6 of 35 hips). Four patients (4 of 35 hips; 11%) required reoperations.

Conclusion

Total hip arthroplasty in patients with corticosteroid-induced osteonecrosis of the femoral head is successful in reducing pain and improving function; however, the rate of complications and reoperation is high.

Objectives To examine mortality and revision rates among patients with osteoarthritis undergoing hip arthroplasty and to compare these rates between patients undergoing cemented or uncemented procedures and to compare outcomes between men undergoing stemmed total hip replacements and Birmingham hip resurfacing.

Design Cohort study.

Setting National Joint Registry.

Population About 275 000 patient records.

Main outcome measures Hip arthroplasty procedures were linked to the time to any subsequent mortality or revision (implant failure). Flexible parametric survival analysis methods were used to analyse time to mortality and also time to revision. Comparisons between procedure groups were adjusted for age, sex, American Society of Anesthesiologists (ASA) grade, and complexity.

Results As there were large baseline differences in the characteristics of patients receiving cemented, uncemented, or resurfacing procedures, unadjusted comparisons are inappropriate. Multivariable survival analyses identified a higher mortality rate for patients undergoing cemented compared with uncemented total hip replacement (adjusted hazard ratio 1.11, 95% confidence interval 1.07 to 1.16); conversely, there was a lower revision rate with cemented procedures (0.53, 0.50 to 0.57). These translate to small predicted differences in population averaged absolute survival probability at all time points. For example, compared with the uncemented group, at eight years after surgery the predicted probability of death in the cemented group was 0.013 higher (0.007 to 0.019) and the predicted probability of revision was 0.015 lower (0.012 to 0.017). In multivariable analyses restricted to men, there was a higher mortality rate in the cemented group and the uncemented group compared with the Birmingham hip resurfacing group. In terms of revision, the Birmingham hip resurfacings had a similar revision rate to uncemented total hip replacements. Both uncemented total hip replacements and Birmingham hip resurfacings had a higher revision rate than cemented total hip replacements.

Conclusions There is a small but significant increased risk of revision with uncemented rather than cemented total hip replacement, and a small but significant increased risk of death with cemented procedures. It is not known whether these are causal relations or caused by residual confounding. Compared with uncemented and cemented total hip replacements, Birmingham hip resurfacing has a significantly lower risk of death in men of all ages. Previously, only adjusted analyses of hip implant revision rates have been used to recommend and justify use of cheaper cemented total hip implants. Our investigations additionally consider mortality rates and suggest a potentially higher mortality rate with cemented total hip replacements, which merits further investigation.

Objective

Subtle deformities of the hip joint are implicated in the etiology of osteoarthritis (OA) of the hip. Parameters that quantify these deformities may aid understanding of these associations. We undertook this study to examine relationships between such parameters and the 19-year risk of total hip arthroplasty (THA) for end-stage OA.

Methods

A new software program designed for measuring morphologic parameters around the hip was developed and validated in a reliability study. THA was the outcome measure for end-stage OA. A nested case–control study was used with individuals from a cohort of 1,003 women who were recruited at year 1 in 1989 and followed up to year 20 (the Chingford Study). All hips with THA by year 20 and 243 randomly selected control hips were studied. Pelvis radiographs obtained at year 2 were analyzed for variations in hip morphology. Measurements were compared between the THA case group and the control group.

Results

Patients with THA had a higher prevalence of cam deformity than did their respective controls (median alpha angle 62.4° versus 45.8° [P = 0.001]; mean modified triangular index height 28.5 mm versus 26.9 mm [P = 0.001]) as well as a higher prevalence of acetabular dysplasia (mean lateral center edge angle 29.5° versus 34.3° [P = 0.001]; median extrusion index 0.25 versus 0.185 [P = 0.009]). Logistic regression analyses clustering by subject and adjusting for radiographic hip OA at year 2 showed that these morphologic parameters were still significantly associated with THA by year 20. The alpha angle and lateral center edge angle predicted the risk of THA independently when included in the same model.

Conclusion

This investigation describes measurements that predict the risk of THA for end-stage OA by year 20, independently of the presence of radiographic hip OA at year 2. These measurements can be made on an anteroposterior pelvis radiograph, which is an inexpensive and commonly used clinical method of investigation.

Purpose

Patient-orientated outcome questionnaires are essential to evaluate treatment success. To compare different treatments, hospitals, and surgeons, standardised questionnaires are required. The present study examined the validity and responsiveness of the Core Outcome Measurement Index for neck pain (COMI-neck), a short, multidimensional outcome instrument.

Methods

Questionnaires were completed by patients with degenerative problems of the cervical spine undergoing cervical disc arthroplasty before (N = 89) and 3 months after (N = 75) surgery. The questionnaires comprised the EuroQol-Five Dimension (EQ-5D), the North American Spine Society Cervical Spine Outcome Assessment Instrument (NASS-cervical) and the COMI-neck.

Results

The COMI and NASS-cervical scores displayed no notable floor or ceiling effects at any time point whereas for the EQ-5D, the highest or lowest values were reached in around 32.5% of patients at follow-up. With one exception (symptom-specific well-being), the individual COMI items and the COMI summary score correlated to the expected extent (R = 0.4–0.8) with the scores of the chosen reference questionnaires. The area under the curve (AUC) generated by ROC analysis was significantly higher for the COMI (0.96) than for any other instrument/subscale when self reported treatment outcome was used as the external criterion, dichotomised as “good” (operation helped a lot/helped) versus “poor” (operation helped only a little/didn’t help/made things worse). The COMI had a high effect size (standardised response mean; SRM) (2.34) for the good global outcome group and a low SRM for the poor outcome group (0.34). The EQ-5D and the NASS-cervical lacked this ability to differentiate between the two groups, showing less distinct SRMs for good and poor outcome groups.

Conclusions

This study provides evidence that the COMI-neck is a valid and responsive questionnaire in the population of patients examined. Further investigations should examine its applicability in other patient groups with less severe neck pain or undergoing other treatment modalities.

Background and purpose

Total Hip Replacement (THA) is one of the most successful and cost-effective operations. Despite its benefits, marked ethnic differences in the utilization of THA are well documented. However, very little has been published on the influence of ethnicity on outcome. We investigate whether the outcome—in terms of reoperation within 2 years or revision up to 14 years after the primary operation—varies depending on ethnic background.

Methods

Records of total hip arthroplasties performed between 1992 and 2007 were retrieved from the Swedish Hip Arthropalsty Registry and integrated with data on ethnicity of patients from 2 demographical databases (i.e. Patient Register and Statistics Sweden). The first operated side in patients with THA recorded in the Swedish Hip Arthroplasty Register (SHAR) between 1992 and 2007 were generally included. We excluded patients with 1 Swedish and 1 non-Swedish parent and patients born abroad with 2 Swedish parents. After these exclusions 151,838 patients were left for analysis. There were 11,539 Swedish patients born outside Sweden. We used a Cox regression model including age, sex, diagnosis, type of fixation, whether or not there was comorbidity according to Elixhauser or not, marital status and educational level.

Results

The mean age was lowest in the group of patient coming from outside Europe including the former Soviet Union (61 years), and highest in the Swedish population (70 years). Before adjustment, for covariates, patients born in Europe outside the Nordic countries showed a lower risk to undergo early reoperation (HR = 0.73, 95% CI: 0.56–0.97), which increased after adjustment to (HR = 0.76, 95% CI: 0.58–1.01). Before adjustment, patients born in the Nordic countries outside Sweden and those born outside Europe (including the former Soviet Union) showed a higher risk to undergo revision than patients born in Sweden (HR = 1.14, 95% CI: 1.02–1.27; HR = 1.49, 95% CI: 1.2–1.9), but this difference disappeared after adjustment for covariates.

Conclusion

We did not find any certain differences in reoperation within 2 years, or revision within 14 years, between patients born in Sweden and immigrants. Further studies are needed to determine whether our observations are biased by the attitude of health providers regarding performance of these procedures, or by a reluctance of certain patient groups to seek medical attention should any complications requiring reoperation or revision occur.

The functional outcomes of periacetabular osteotomy (PAO) and factors predicting outcome in the older patient with acetabular dysplasia are not well understood. We therefore retrospectively determined the functional outcome of 70 patients (87 hips) over age 40 treated with PAO in three institutions; we also determined whether preoperative factors, particularly the presence of osteoarthritis, influenced the survival of the hip or time to total hip arthroplasty after PAO. The average age at surgery was 43.6 years. The minimum followup was 2 years (mean, 4.9 years; range, 2–13 years). Twenty-one hips (24%) had undergone total hip arthroplasty (THA), at a mean of 5.2 years after PAO (range, 1.9–7.6 years). Surviving hips had a mean improvement in Harris hip score from 60.7 to 90.3 and in total WOMAC pain score from 8.7 to 3. We observed no differences in preoperative or postoperative radiographic measurements or preoperative clinical function scores (HHS, WOMAC) in hips surviving and hips having THA. The risk of THA at 5 years after PAO was 12% in hips with preoperative Tönnis Grade 0 or 1 and 27% for Tönnis Grade 2. Our preliminary study suggests that PAO will give satisfactory functional and pain scores in patients over age 40 having dysplastic hips with mild or no arthrosis.

Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Summary

Objective

To evaluate the measurement properties of a new osteoarthritis (OA) pain measure.

Methods

The new tool, comprised of 12 questions on constant vs intermittent pain was administered by phone to 100 subjects aged 40+ years with hip or knee OA, followed by three global hip/knee questions, the Western Ontario and McMaster Universities (WOMAC) pain subscale, the symptom subscales of the Hip Disability and OA Outcome Score (HOOS) or Knee Injury and OA Outcome Score (KOOS), and the limitation dimension of the Late Life Function and Disability Instrument (LLFDI). Test-retest reliability was assessed by re-administration after 48–96 h. Item response distributions, inter-item correlations, item-total correlations and Cronbach's alpha were assessed. Principle component analysis was performed and test-retest reliability was assessed by intra-class correlation coefficient (ICC).

Results

There was good distribution of response options across all items. The mean intensity was higher for intermittent vs constant pain, indicating subjects could distinguish the two concepts. Inter-item correlations ranged from 0.37 to 0.76 indicating no item redundancy. One item, predictability of pain, was removed from subsequent analyses as correlations with other items and item-total correlations were low. The 11-item scale had a corrected inter-item correlation range of 0.54–0.81 with Cronbach's alpha of 0.93 for the combined sample. Principle components analysis demonstrated factorial complexity. As such, scoring was based on the summing of individual items. Test-retest reliability was excellent (ICC 0.85). The measure was significantly correlated with each of the other measures [Spearman correlations −0.60 (KOOS symptoms) to 0.81 (WOMAC pain scale)], except the LLFDI, where correlations were low.

Conclusions

Preliminary psychometric testing suggests this OA pain measure is reliable and valid.

Background and purpose

Hip resurfacing arthroplasty (RHA) is done in patients who often have a high preference for the method. This preference can influence the clinical outcome and satisfaction. We evaluated the potential influence of this preference bias.

Patients and methods

From an ongoing randomized trial comparing RHA with total hip arthroplasty, 28 consecutive patients (28 hips) who had been allocated to an RHA were characterized as the “randomized” group. 22 other patients (24 hips) who had refused participation and had especially requested an RHA were characterized as the “preference” group. Harris hip score (HHS), Oxford hip score (OHS), University of California at Los Angeles activity scale (UCLA), Short Form 12 (SF-12), and visual analog scale satisfaction score (VAS) were assessed in both groups.

Results

Both groups had a high implant satisfaction score (97/100 for the “preference” group and 93/100 for the “randomized” group) at 12 months. The HHS, OHS, and UCLA were similar at baseline and also revealed a similar improvement up to 12 months (p < 0.001). Regarding the SF-12, the “preference” group scored lower on the mental subscale preoperatively (p = 0.03), and there was a greater increase after 12 months (p = 0.03).

Interpretation

We could not show that there was any influence of preference on satisfaction with the implant and early clinical outcome in patients who underwent RHA. The difference in mental subscale scores between groups may still indicate a difference in psychological profile.

Total hip arthroplasty (THA) with well designed cementless acetabular implants has shown excellent results. The purpose of this study was to assess our clinical and radiological outcomes using an uncemented cup. We conducted a prospective cohort study including all consecutive primary THAs performed with the Morscher press-fit cup, an uncemented non-modular acetabular component, between March 1996 and December 1998. Patients were evaluated at ten years with clinical and radiological follow-up, patient satisfaction and questionnaire assessment using the Harris hip score (HHS), Merle d’Aubigné and Postel score, the UCLA score, the 12-item short-form health survey (SF-12) and a visual analog scale. Five hundred sixty-one THAs were performed in 518 patients. At 120 months (± 7.3 months), 303 patients with 335 THAs were still available for follow-up. None of the patients had required cup revision for aseptic loosening. At ten years, the cup survivorship was 98.8% (95% CI 97.4–99.5) with cup revision for any cause as an endpoint. No radiolucencies were seen around the cups, but osteolytic defects involved 21 stems (8.3%). Mean total linear polyethylene wear was 0.9 mm. The Morscher acetabular replacement cup provides excellent results at ten years. There were no revisions for aseptic loosening of the cup, and no osteolytic defects were found around the cup. Patient satisfaction was high and the clinical results were very good.

Background

Surgeons strive to set patient expectations for recovery following total hip arthroplasty (THA) and total knee arthroplasty (TKA). However, some patients report dissatisfaction after surgery due to unmet expectations.

Purpose

We compared patients’ and surgeon’s recovery expectations prior to primary THA and TKA.

Methods

Sixty eight patients scheduled to undergo primary total hip replacement (THR) or total knee replacement (TKR) surgery were enrolled. Before surgery, patients filled out a validated recovery expectations questionnaire that quantified expectations of postoperative pain relief, function, and well-being with a value from 0 to 100 (higher being more optimistic). The surgeon independently completed the same questionnaire for each patient. Overall score and item-specific comparisons were conducted. Correlations were explored between agreement level, demographics, patient-reported health status measures, and patients’ assessments of the risk of complications associated with surgery.

Results

Most patients undergoing THR or TKR had higher expectations for recovery than their surgeon. Applying the clinically meaningful difference in expectations (≥7 points), 52.5% of the TKA patients’ expectations exceeded those of the surgeon, while 22.5% expected less than their surgeon and 60.7% of THA patients’ expectations exceeded those of the surgeon, while 21.4% expected less than their surgeon. THA patients with either lower or higher expectations than their surgeon had lower physical and mental health status scores. TKA patients with lower expectations compared to their surgeon had a higher expectation of complications.

Conclusions

More than 50% of the patients had higher expectations than their surgeon and this was driven by expectations of high-level activities and extreme range of motion. Further investigations are needed to understand these differences so as to enhance patient preoperative education.

Background

Although intra-articular hyaluronic acid is well established as a treatment for osteoarthritis of the knee, its use in hip osteoarthritis is not based on large randomized controlled trials. There is a need for more rigorously designed studies on hip osteoarthritis treatment as this subject is still very much under debate.

Methods/Design

Randomized, controlled trial with a three-armed, parallel-group design. Approximately 315 patients complying with the inclusion and exclusion criteria will be randomized into one of the following treatment groups: infiltration of the hip joint with hyaluronic acid, with a corticosteroid or with 0.125% bupivacaine.

The following outcome measure instruments will be assessed at baseline, i.e. before the intra-articular injection of one of the study products, and then again at six weeks, 3 and 6 months after the initial injection: Pain (100 mm VAS), Harris Hip Score and HOOS, patient assessment of their clinical status (worse, stable or better then at the time of enrollment) and intake of pain rescue medication (number per week). In addition patients will be asked if they have complications/adverse events. The six-month follow-up period for all patients will begin on the date the first injection is administered.

Discussion

This randomized, controlled, three-arm study will hopefully provide robust information on two of the intra-articular treatments used in hip osteoarthritis, in comparison to bupivacaine.

Trial registration

NCT01079455