Machine-learning vs. logistic regression for preoperative prediction of medical morbidity after fast-track hip and knee arthroplasty-a comparative study.

BACKGROUND: Machine-learning models may improve prediction of length of stay (LOS) and morbidity after surgery. However, few studies include fast-track programs, and most rely on administrative coding with limited follow-up and information on perioperative care. This study investigates potential benefits of a machine-learning model for prediction of postoperative morbidity in fast-track total hip (THA) and knee arthroplasty (TKA). METHODS: Cohort study in consecutive unselected primary THA/TKA between 2014-2017 from seven Danish centers with established fast-track protocols. Preoperative comorbidity and prescribed medication were recorded prospectively and information on length of stay and readmissions was obtained through the Danish National Patient Registry and medical records. We used a machine-learning model (Boosted Decision Trees) based on boosted decision trees with 33 preoperative variables for predicting "medical" morbidity leading to LOS > 4 days or 90-days readmissions and compared to a logistical regression model based on the same variables. We also evaluated two parsimonious models, using the ten most important variables in the full machine-learning and logistic regression models. Data collected between 2014-2016 (n:18,013) was used for model training and data from 2017 (n:3913) was used for testing. Model performances were analyzed using precision, area under receiver operating (AUROC) and precision recall curves (AUPRC), as well as the Mathews Correlation Coefficient. Variable importance was analyzed using Shapley Additive Explanations values. RESULTS: Using a threshold of 20% "risk-patients" (n:782), precision, AUROC and AUPRC were 13.6%, 76.3% and 15.5% vs. 12.4%, 74.7% and 15.6% for the machine-learning and logistic regression model, respectively. The parsimonious machine-learning model performed better than the full logistic regression model. Of the top ten variables, eight were shared between the machine-learning and logistic regression models, but with a considerable age-related variation in importance of specific types of medication. CONCLUSION: A machine-learning model using preoperative characteristics and prescriptions slightly improved identification of patients in high-risk of "medical" complications after fast-track THA and TKA compared to a logistic regression model. Such algorithms could help find a manageable population of patients who may benefit most from intensified perioperative care.

Less early subsidence of cemented Exeter short stems compared with cemented Exeter standard stems in Dorr type A femurs.

Aims: The Exeter short stem was designed for patients with Dorr type A femora and short-term results are promising. The aim of this study was to evaluate the minimum five-year stem migration pattern of Exeter short stems in comparison with Exeter standard stems. Methods: In this case-control study, 25 patients (22 female) at mean age of 78 years (70 to 89) received cemented Exeter short stem (case group). Cases were selected based on Dorr type A femora and matched first by Dorr type A and then age to a control cohort of 21 patients (11 female) at mean age of 74 years (70 to 89) who received with cemented Exeter standard stems (control group). Preoperatively, all patients had primary hip osteoarthritis and no osteoporosis as confirmed by dual X-ray absorptiometry scanning. Patients were followed with radiostereometry for evaluation of stem migration (primary endpoint), evaluation of cement quality, and Oxford Hip Score. Measurements were taken preoperatively, and at three, 12, and 24 months and a minimum five-year follow-up. Results: At three months, subsidence of the short stem -0.87 mm (95% confidence interval (CI) -1.07 to -0.67) was lower compared to the standard stem -1.59 mm (95% CI -1.82 to -1.36; p < 0.001). Both stems continued a similar pattern of subsidence until five-year follow-up. At five-year follow-up, the short stem had subsided mean -1.67 mm (95% CI -1.98 to -1.36) compared to mean -2.67 mm (95% CI -3.03 to -2.32) for the standard stem (p < 0.001). Subsidence was not influenced by preoperative bone quality (osteopenia vs normal) or cement mantle thickness. Conclusion: The standard Exeter stem had more early subsidence compared with the short Exeter stem in patients with Dorr type A femora, but thereafter a similar migration pattern of subsidence until minimum five years follow-up. Both the standard and the short Exeter stems subside. The standard stem subsides more compared to the short stem in Dorr type A femurs. Subsidence of the Exeter stems was not affected by cement mantle thickness.

Distal radioulnar joint kinematics before surgery and 12 months following open foveal reinsertion of the triangular fibrocartilage complex: comparison with the contralateral non-injured joint.

BACKGROUND AND PURPOSE: Foveal triangular fibrocartilage complex (TFCC) lesion may cause distal radioulnar joint (DRUJ) instability. Dynamic radiostereometry (dRSA) has been validated for objective measurement of DRUJ kinematics. We evaluated DRUJ kinematics by dRSA before surgery and 12 months following open foveal reinsertion of the TFCC in comparison with contralateral non-injured DRUJs. PATIENTS AND METHODS: In a prospective cohort study, 21 patients (11 men) of mean age 34 years (22-50) with arthroscopically confirmed foveal TFCC lesion were evaluated preoperatively, and at 6 and 12 months after open foveal TFCC reinsertion with QDASH, PRWE, pain on NRS, and bilateral dRSA imaging during a patient active press test motion cycle, including a force-loaded downstroke and a release phase. RESULTS: Preoperatively, the force-loaded part (> 2.3 kg; 95% CI 1.6-3.0) of the press test motion cycle (from 15% to 75%) revealed a more volar position of the ulnar head in the sigmoid notch (DRUJ position ratio) and increased distance in DRUJs with foveal TFCC lesion compared with the patients' contralateral non-injured DRUJ (p < 0.05). 6 months postoperatively, the DRUJ position was generally normalized and remained normalized at 12 months. However, the DRUJ distance remained higher on the injured side. 12 months postoperatively, patients reported less pain during activities, with improved QDASH and PRWE scores (p < 0.007). INTERPRETATION: DRUJ kinematics during the press test showed increased DRUJ translation to a more volar position of the ulnar head after foveal TFCC lesion compared with the contralateral non-injured DRUJs. Open foveal TFCC reinsertion had a stabilizing effect on DRUJ kinematics towards normalization, and improved patient-reported outcomes 6 and 12 months after surgery.

Reducing patient-staff contact in fast-track total hip arthroplasty has no effect on patient-reported outcomes, but decreases satisfaction amongst patients with self-perceived complications: analysis of 211 patients.

BACKGROUND AND PURPOSE: Several studies have compared fast-track with conventional pathways for total hip arthroplasty (THA) patients, but none have compared different fast-track pathways. Due to COVID-19 restrictions, our department had to minimize patient-staff contact in the THA pathway. First, telephone consultations were implemented instead of an outpatient clinic visit and subsequently preoperative patient education was discontinued. This enabled us to compare patient-reported outcomes and satisfaction among 3 fast-track pathways. PATIENTS AND METHODS: We collected data from patients treated for hip osteoarthritis with THA at Gødstrup Hospital between 2018 and 2021. The patients had experienced 1 of 3 pathways and were interviewed via telephone between 2 and 6 months after discharge. We analyzed the influence of patient pathway on patient-reported pain and mobility level, self-perceived complications, and compliance using logistic regression. We then compared the pathway's effect on patient satisfaction both for the total sample and for the patients who experienced complications. RESULTS: The amount of patient-staff contact in the patient pathway did not have any influence on patientreported outcomes or the probability of self-perceived complications. For the full sample, patient-staff contact had no statistically significant influence on patient satisfaction either, but for the subgroup of patients experiencing complications, the pathways with less patient-staff contact reduced satisfaction. Patient satisfaction was primarily related to pain and mobility outcomes. INTERPRETATION: Our results indicate that reducing patient-staff contact in fast-track THA can be done without influencing mobility and pain outcomes, but the overall satisfaction among patients with self-perceived complications will be negatively affected.

Poor adherence to guidelines in treatment of fragile and cognitively impaired patients with hip fracture: a descriptive study of 2,804 patients.

Background and purpose - Following a hip fracture, most patients will encounter poorer functional outcomes and an increased risk of death. Treatment-monitoring of hip fracture patients is in many countries done by national audits. However, they do not allow for a deeper understanding of treatment limitations. We performed a local evaluation study to investigate adherence to 7 best-practice indicators, and to investigate patient groups at risk of suboptimal treatment.Patients and methods - 2,804 patients were surgically treated for a hip fracture from 2011 to 2017 at our institution. Data regarding admission, hospital stay, and discharge was prospectively collected, and adherence to the 7 best practice indicators (nerve block, surgical delay, antibiotics, implant choice, thromboprophylaxis, mobilization, and blood transfusions) was analyzed. Patient groups with lower adherence were identified.Results - 34% of patients received all 7 best practice indicators after considering contraindications; in particular, nerve blocks and thromboprophylaxis displayed low adherence at 61% and 91% respectively. Nursing home residents and patients with cognitive impairment, multiple comorbidities, or low functional levels were at risk of having a lower adherence.Interpretation - The most dependent patients with cognitive impairment, comorbidities, or low functional levels had lower guideline adherence. This large patient subgroup needs a higher treatment focus and more resources. Our findings are likely similar to those in other national and international institutions.

Revision rates of trapeziometacarpal total joint arthroplasty in relation to occupational hand force requirements.

The purpose was to determine revision rates after trapeziometacarpal total joint arthroplasty in working age patients, hypothesizing that higher occupational hand force requirements lead to higher revision rates. We conducted a follow-up study of patients operated 2003-2015. Self-reported job titles at the time of primary surgery were linked with a job exposure matrix to estimate occupational hand force requirements. Time until revision was analysed using Cox regression. The study comprised 222 patients aged 39-65 years (mean 55, SD 6), including 133 patients in the labour market. The median follow-up period was 5 years (interquartile range 4-7) and the overall revision rate was 5/100 person-years. For high versus low occupational hand force requirements, the hazard ratio was 1.5 (95% confidence interval 0.5-4.4). For patients outside the labour market, the hazard ratio was 2.3 (0.9-5.6). Our results did not indicate large effects of high occupational hand force requirements on revision rates.Level of evidence: IV.

Total trapeziometacarpal joint arthroplasty using wide awake local anaesthetic no tourniquet.

We conducted a descriptive study of 50 consecutive cases of total trapeziometacarpal joint arthroplasty by one surgeon using wide awake local anaesthetic no tourniquet to assess the usefulness and reliability of the anaesthesia, any adverse effects and patient acceptance. No difference was found when comparing the duration of surgery with 50 cases of total trapeziometacarpal joint arthroplasty inserted in a bloodless field under general or regional anaesthesia by the same surgeon. Wide awake local anaesthetic no tourniquet was found to be useful in providing adequate anaesthesia and haemostasis, and to be reliable and safe with no adverse effects. Patient satisfaction was high with 100% willing to repeat. Overall, wide awake local anaesthetic no tourniquet was a satisfactory method of anaesthesia for trapeziometacarpal joint arthroplasty with the potential for significant benefits to both patient and surgeon compared with traditional general anaesthesia and regional block.Level of evidence: II.

The mechanical fixation of a cementless conical cup in cortical versus cancellous trapezial bone: an experimental study.

In a pig bone model mimicking the human trapezium, we assessed the cementless fixation of trapezial cups in cancellous and cortical bone. Thirty-two saddle-shaped pig forefoot bones were prepared for cup fixation. Conical Konos cups (Beznoska, Kladno, Czech Republic) size 9 mm or 10 mm diameter were impacted. Cup migration was evaluated with repeated radiostereometry after intervals of cyclic-load tests. Migration increased for every load-interval up to 750 N and was higher with cancellous bone fixation than with cortical bone fixation. In cancellous bone, 9 mm cups migrated more than 10 mm cups. At the highest load (1050 N), the cumulative implant survival was 88% for 10 mm cups with cortical bone fixation and 13% for 9 mm cups with cancellous bone fixation. We conclude that mechanical fixation of conical Konos cups was better in cortical than in cancellous bone. Our results further suggest that the largest possible cup diameter should be used.

Inferior stabilization of cementless compared with cemented dual-mobility cups in elderly osteoarthrosis patients: a randomized controlled radiostereometry study on 60 patients with 2 years' follow-up.

Background and purpose - Elderly patients may benefit from a dislocation low-risk dual-mobility (DM) articulation in total hip arthroplasty, but the best cup fixation method is unknown. We compared cup migration for cemented and cementless DM cups using radiostereometry.Patients and methods - In a patient-blinded randomized trial, 60 patients (33 female) with osteoarthritis were allocated to cemented (n = 30) or cementless (n = 30) Avantage DM cup fixation. Criteria were age above 70 years, and T-score above -4. We investigated cup migration, periprosthetic bone mineral density (BMD), and patient-reported outcome measures (PROMs) until 24 months postoperative follow-up.Results - At 24 months mean proximal cup migration was 0.11 mm (95% CI 0.00-0.23) for cemented cups and 0.09 mm (CI -0.09 to 0.28) for cementless cups. However, cementless cups generally migrated more than cemented cups at 12 and 24 months. Cemented cups had no measurable migration from 3 months' follow-up, while cementless cups had not yet stabilized at 24 months in all rotations. Cementless cups showed statistically significantly more maximum total point motion (MTPM) at 12- and 24-month follow-up compared with cemented cups in patients with low systemic BMD (p = 0.01). Periprosthetic BMD changes did not statisticially significantly correlate to proximal migration in either cup fixation group (p > 0.05). PROMs improved similarly in both groups.Interpretation - Cemented cups were well fixed at 3 months. The cementless cups migrated more in patients with low BMD, showed an inconsistent pattern of migration, and migrated in different directions during the first and second year without tendency to stabilization. Cemented fixation of the Avantage DM cup seems safer in elderly patients.

The Effect of Bone Quality on Tibial Component Migration in Medial Cemented Unicompartmental Knee Arthroplasty. A Prospective Cohort Study Using Dual X-Ray Absorptiometry and Radiostereometric Analysis.

BACKGROUND: Periprosthetic bone mineral density (BMD) may influence implant fixation and subsequent loosening. Unicompartmental knee arthroplasty (UKA) restores normal knee kinematics and load distribution to the surrounding bone. We studied the influence of systemic and periprosthetic BMD of the proximal tibia on migration of the tibial component of cemented medial UKA. METHODS: The cohort was dichotomized into a normal BMD group (T-score ≥ -1; n = 37) and a low BMD group (T-score < -1; n = 28) according to World Health Organization criteria. BMD of the proximal tibia and migration of the tibial component were measured with dual X-ray absorptiometry scans and stereoradiographs with 2-year follow-up. RESULTS: Patients with normal systemic BMD had an 11% to15% higher BMD in all regions of interest (ROIs) compared to patients with low systemic BMD throughout follow-up. Over time, a decrease in periprosthetic BMD in ROI 1-3 was seen for both groups. The operated knees and contralateral knees showed a similar reduction in BMD in all ROIs between preoperative and 24 months. Between 12 and 24 months, the normal BMD group migrated (maximal total point motion) 0.03 mm (95% confidence interval, -0.01, 0.08) and the low BMD group migrated 0.02 mm (95% confidence interval, -0.03, 0.07). Migration over time was not influenced by change in periprosthetic BMD. CONCLUSION: Migration of cemented medial tibial UKA was low until 24 months and was neither affected by preoperative systemic BMD nor affected by postoperative change in periprosthetic BMD. This suggests good long-term fixation despite an index difference in proximal tibial BMD.

Equal tibial component fixation of a mobile-bearing and fixed-bearing medial unicompartmental knee arthroplasty: a randomized controlled RSA study with 2-year follow-up.

Background and purpose - Differences in stress distribution in a mobile-bearing and fixed-bearing unicompartmental knee arthroplasty (UKA) design might lead to a difference in fixation of the tibial component. We compared tibial component migration of a mobile-bearing (MB) UKA and a fixed-bearing (FB) UKA using radiostereometric analysis.Patients and methods - In a randomized, patient-blinded clinical trial 62 patients received either the MB Oxford UKA or the FB Sigma UKA. The patients were followed for 24 months with radiostereometric analysis. Clinical outcome was assessed with Oxford Knee Score (OKS), RAND-36 and leg extension power.Results - Migration of the tibial components was similar between groups throughout follow-up. At 12 months, MTPM of the tibial component was 0.44 mm (95% CI 0.34-0.55) for the MB group and 0.40 mm (CI 0.31-0.50) for the FB group. Between 12 and 24 months, the tibial components migrated with a median MTPM increase of 0.03 mm (CI -0.02 to 0.08) in the MB group and 0.03 mm (CI -0.02 to 0.07) in the FB group. Continuous migration of the tibial component was found for 1 MB UKA and 2 FB UKAs. Both groups showed similar and clinically relevant improvement in clinical outcome.Interpretation - MB and FB tibial components had similar good fixation and clinical improvement until 2 years. Based on this study, a low 5- to 10-year revision rate can be expected for both implants.

Delay in surgery, risk of hospital-treated infections and the prognostic impact of comorbidity in hip fracture patients. A Danish nationwide cohort study, 2005-2016.

Purpose: We examined the association between delay in surgery and hospital-treated infections in hip fracture patients with and without known comorbidities. Patients and methods: All hip fracture patients aged ≥65 years registered in the Danish Multidisciplinary Hip Fracture Registry from 2005 to 2016 were included (n=72,520). Delay in surgery was defined as the time in hours from admission to surgery and was divided into 3 groups (12, 24 and 48 hrs). The outcomes were hospital-treated pneumonia, urinary tract infection and reoperation due to infection 0-30 days after surgery. As a measure of comorbidity, we used the Charlson Comorbidity Index (CCI): none (no registered comorbidities prior to the fracture), medium (1-2 points) and high (≥3 points). Results: Overall, there was an association between a delay of 12 hrs and pneumonia. A delay of 12 hrs was associated with an increased risk of pneumonia in patients with no comorbidities (adjusted hazard ratio (HR) 1.20, confidence interval (CI) 1.03-1.40) and a delay of 24 hrs was associated with an increased risk of pneumonia in patients with a medium level of comorbidity (HR 1.12, CI (1.02-1.23)). Overall, delay was associated with reoperation due to infection, particularly among patients with comorbidities, although the confidence intervals of some of the estimates were wide. A delay of 48 hrs was associated with an increased risk of reoperation due to infection in patients with a high level of comorbidity (HR 2.36, CI 1.19-4.69). Conclusion: Delay in surgery was associated with an increased risk of hospital-treated pneumonia and reoperations due to infection within 30 days of surgery. The number of postoperative hospital-treated infections within 30 days may be reduced by continuously targeting pre-, per- and postoperative optimization not only for patients with high level of comorbidity but also for hip fracture patients without known comorbidities prior to surgery.

Indwelling urinary catheterisation may increase risk of complications in hip and knee arthroplasty.

INTRODUCTION: Routine use of perioperative indwelling urinary catheterisation in fast-track total hip arthroplasty (THA) and total knee arthroplasty (TKA) is still debatable, as urinary catheterisation may cause complications. The aim of this study was to describe the incidence of re-catheterisa-tion and urologic complications during the initial 30 days following THA and TKA fast-track surgery. METHODS: We conducted a prospective, observational study of 795 patients ≥ 50 years of age who had undergone elective fast-track THA or TKA with perioperative indwelling urinary catheterisation until the first post-operative morning. Primary outcomes were number of patients keeping their catheter the first post-operative morning and the incidence of re-catheterisations before discharge. Follow-up on post-discharge complications was done by phone 30 days after surgery. RESULTS: A total of 784 of 795 included patients (98.6%) were analysed for the primary outcomes, and follow-up data were available for 760 patients (95.6%). Three patients (0.4%) kept their catheter after the first post-operative morning and 25 patients (3.2%) were re-catheterised before discharge. The median length of stay was two days (interquartile range: 1-2). The incidence of post-operative urinary tract infections (UTI) was 4.2%, and about 30% of the patients experienced pre-to-post-operative aggravation of their lower urinary tract symptoms. CONCLUSIONS: Routine use of perioperative indwelling urinary catheterisation in fast-track THA and TKA may increase the risk of post-operative UTI and does not eliminate the need for subsequent re-catheterisation. These findings speak against routine use of perioperative indwelling catheterisation. FUNDING: The study was supported by the Lundbeck Foundation and registered with clinicaltrials.gov. TRIAL REGISTRATION: clinicaltrials.gov 8 April 2014 (NCT02133768).

Impact of preadmission anti-inflammatory drug use on the risk of RBC transfusion in elderly hip fracture patients: a Danish nationwide cohort study, 2005-2016.

BACKGROUND: Do prescription drugs with anti-inflammatory properties such as nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids, and statins increase the risk of postoperative bleeding measured with RBC transfusion in elderly hip fracture surgery patients? STUDY DESIGN AND METHODS: Using the Danish Multidisciplinary Hip Fracture Database, 74,791 patients aged 65 years or older with surgery-treated hip fracture were identified during 2005-2016, and their use of NSAIDs, corticosteroids, and statins was ascertained. For each drug, patients were categorized as nonusers (no prescription ≤365 days prior to surgery), former users (one prescription 91-365 days), and current users (one prescription ≤90 days). Information on surgical treatment, transfusion, other medication and comorbidities were collected using Danish nationwide registries. A log-binomial model was used to estimate relative risks for RBC transfusion within 7 days of surgery and corresponding 95% confidence intervals. Adjustments were made for patient- and surgery-related factors. RESULTS: Former and current users of NSAIDs, corticosteroids, and statins accounted for 22%, 10%, and 24%, respectively. Current users of NSAIDs had an increased adjusted relative risk of transfusion (1.07; confidence interval, 1.04-1.10) compared to nonusers. There was no association between current users of corticosteroids and statins and risk of transfusion. CONCLUSION: NSAID use within 90 days of a hip fracture surgery was associated with an increased risk of RBC transfusion. Thus, current use of NSAIDs can be associated with an increased risk of postoperative bleeding, but we cannot rule out the influence of confounding.

Low dislocation rate of Saturne®/Avantage® dual-mobility THA after displaced femoral neck fracture: a cohort study of 966 hips with a minimum 1.6-year follow-up.

INTRODUCTION: Dislocation is a serious and common complication and a great concern with the use of total hip arthroplasty (THA) when treating displaced femoral neck fracture (FNF). Dual-mobility (DM) THA might reduce the dislocation risk. We aim to report the dislocation and revision rate of primary DM THA in patients with displaced FNF. MATERIALS AND METHODS: Between 2005 and 2015, 966 consecutive patients (676 women) at mean age 80.5 years (range 42-104) with displaced FNF were operated with DM articulation THA by posterolateral approach (PLA). Patient files and radiographs were evaluated for dislocations, revisions, and other complications until death of the patient or August 1st, 2017. Data were crosschecked with the National Patient Registry. Patient's mental state was tested upon admissions. Surgeon's educational level was noted and post-operative cup position was measured. RESULTS: At minimum 1.6-year follow-up, there were 45 (4.7%) dislocations and eight (0.8%) cup revisions. The 30-day mortality was 9.2% and 533 patients (55.2%) were dead at the time of last follow-up. We observed eight intraprosthetic dislocations (IPD); six occurred in relation to closed reduction. Cementless stem fixation was associated with higher dislocation risk (p = 0.04) and higher rate of stem complications (p = 0.002). There was no significant association between cognitive impairment and dislocation (OR 2.0, 95% CI 0.96-4.34, p = 0.06). CONCLUSION: Overall, DM THA inserted via PLA results in an acceptable dislocation risk and low revision rate in fragile, old patients with acute FNF fracture, regardless of mental status. A unique complication in DM THA is IPD, which requires an immediate open reduction surgery.

Higher UHMWPE wear-rate in cementless compared with cemented cups with the Saturne® Dual-Mobility acetabular system.

INTRODUCTION: Dual mobility (DM) total hip arthroplasty (THA) may reduce dislocation risk, but might increase the risk of high polyethylene (PE) wear due to double wearing surfaces. METHODS: 127 patients (97 female) with 129 hips operated with THA after displaced femoral neck fracture FNF between 2005 and 2011, were seen for a cross-sectional clinical follow-up. Acetabular components were Saturne® DM cups with 28mm chrome-cobalt heads in UHMWPE. Cementless cups (n = 73) were hydroxyapatite coated. Radiographs were obtained for analysis of cup placement, 2D polyethylene wear and wear-rate (PolyWare 3D), and further radiological evaluation. Activity measurements included Timed Up and Go test (TUG) and walking distance from Harris Hip Score (HHS). RESULTS: At a mean follow-up of 2.83 (1.0-7.7) years the mean wear was 0.82 mm (range 0.17-4.51, SD 0.50), and the wear-rate was 0.37 mm (range 0.06-1.90, SD 0.29). Wear-rate of 0.43 mm/year (SD 0.30) in cementless cups was higher (p = 0.004) than 0.30 mm/year (SD 0.27) in cemented cups. Mean age at time of surgery was 75.1 years (range 30-95). There was no correlation between age at time of surgery and wear (p = 0.56). There was no correlation between cup inclination and wear-rate (p = 0.35). TUG was mean 13.4 seconds (range 4.5-30.1) and correlated with wear rate (p = 0.03). CONCLUSIONS: At short term follow-up, the mean wear-rate in old and low demand patients was high, correlated to activity, and was above the generally accepted osteolysis threshold (0.1 mm/yr.). Cementless HA-coated cups had higher wear-rate than cemented cups.

Good function and high patient satisfaction at mean 2.8 years after dual mobility THA following femoral neck fracture: a cross-sectional study of 124 patients.

AIMS: Our aim was to investigate function, health status and satisfaction in patients treated with primary dual mobility (DM) total hip arthroplasty (THA) after displaced femoral neck fracture (FNF). PATIENTS AND METHODS: From 2005-2011, 414 consecutive FNF patients received Saturne DM THA. At a minimum of 1-year follow-up, 124 (95 women) were evaluated with Oxford Hip Score (OHS), Harris Hip Score (HHS), health-related quality of life (HRQoL) measure (EQ-5D) and two functional tests: Timed Up and Go (TUG) and Sit to Stand 10 times (STS). The FNF patients were matched 1:2 by age, sex and surgery date with patients receiving THA due to osteoarthrosis (OA group) and 1-year OHS and EQ5D were compared. FNF patients were matched by age and sex with the general population index (GPI) for EQ-5D comparison. RESULTS: Patient age at surgery after FNF was mean 74.8 (range 30-92) years. At mean follow-up of 2.8 (range 1.0-7.7) years, mean EQ-5D score was 0.79 (SD 0.15) in the FNF group, which was similar to the matched GPI (p = 0.4), but lower (p = 0.014) compared to the OA group. Mean OHS was 36.4 (SD 9.5) in the FNF group and 38.4 (SD 7.2) in the OA group (p = 0.18). HHS in the FNF group was 78.7 (SD 15.5). Mean TUG time was 13.5 (SD 4.9) secs, and mean STS was 37.9 (SD 15.3) secs. Eighty nine percent (n = 111) of FNF patients were satisfied with the operation result. CONCLUSION: DM THA following displaced FNF provides a good functional result and quality of life in addition to high patient satisfaction.

Is gain in health-related quality of life after a total hip arthroplasty depended on the comorbidity burden?

Background and purpose - Using patient-reported health-related quality of life (HRQoL), approximately 10% of patients report some degree of dissatisfaction after a total hip arthroplasty (THA). The preoperative comorbidity burden may play a role in predicting which patients may have limited benefit from a THA. Therefore, we examined whether gain in HRQoL measured with the EuroQol-5D (EQ-5D) at 3 and 12 months of follow-up depended on the comorbidity burden in THA patients Patients and methods - 1,582 THA patients treated at the Regional Hospital West Jutland from 2008 to 2013 were included. The comorbidity burden was collected from an administrative database and assessed with the Charlson Comorbidity Index (CCI). The CCI was divided into 3 levels: no comorbidity burden, low, and high comorbidity burden. HRQoL was measured using the EQ-5D preoperatively and at 3 and 12 months' follow-up. Association between low and high comorbidity burden compared with no comorbidity burden and gain in HRQoL was analyzed with multiple linear regression. Results - All patients, regardless of comorbidity burden, gained significantly in HRQoL. A positive association between comorbidity burden and gain in HRQoL was found at 3-month follow-up for THA patients with a high comorbidity burden (coeff: 0.09 (95% CI 0.02 - 0.16)) compared with patients with no comorbidity burden. Interpretation - A comorbidity burden prior to THA does not preclude a gain in HRQoL up to 1 year after THA.

The impact of age and preoperative health-related quality of life on patient-reported improvements after total hip arthroplasty.

BACKGROUND: Total hip arthroplasty (THA) is a common surgical procedure and approximately 9,500 of these surgeries are performed annually in Denmark. The operation is considered effective and successful with respect to complications, mortality, and implant survival. However, using patient-reported outcome measures, up to 10% of patients are not satisfied with the outcome of their operation. To address this, it is important to find out why some patients experience impaired outcomes after THA. The purpose of this study was to investigate the impact of age and preoperative health-related quality of life (HRQoL) on improvements in HRQoL after THA. METHODS: A cohort study was conducted with follow-up at 3 and 12 months. Patients were included from September 2008 to December 2013. We analyzed 1,283 THA cases. HRQoL was measured using the EuroQol-5 Domain. Analyses were carried out with multiple linear regression and adjusted for relevant variables available in the data set. RESULTS: A significant positive association was found between age and HRQoL outcomes for patients who underwent THA at both 3 (ß [regression coefficient] 0.0026, confidence interval [CI] 0.0013; 0.0039, p<0.001) and 12 (ß 0.0020 CI 0.0008; 0.0032, p=0.001) months of follow-up. A clinically relevant change was achieved with an increase in age of 12-15 years. A significant negative association was found between preoperative HRQoL and HRQoL outcomes at both 3 (ß -0.841 CI -0.886; -0.795, p<0.001) and 12 (ß -0.804 CI -0.844; -0.764, p<0.001) months of follow-up. CONCLUSION: Contrary to our expectations, older patients had more improvements in HRQoL outcomes after THA. A high preoperative HRQoL seems to inhibit improvements in HRQoLs after THA.

Higher UHMWPE wear-rate in cementless compared with cemented cups with the Saturne® Dual-Mobility acetabular system.

INTRODUCTION: Dual mobility (DM) total hip arthroplasty (THA) may reduce dislocation risk, but might increase the risk of high polyethylene (PE) wear due to double wearing surfaces. METHODS: 127 patients (97 female) with 129 hips operated with THA after displaced femoral neck fracture FNF between 2005 and 2011, were seen for a cross-sectional clinical follow-up. Acetabular components were Saturne® DM cups with 28mm chrome-cobalt heads in UHMWPE. Cementless cups (n = 73) were hydroxyapatite coated. Radiographs were obtained for analysis of cup placement, 2D polyethylene wear and wear-rate (PolyWare 3D), and further radiological evaluation. Activity measurements included Timed Up and Go test (TUG) and walking distance from Harris Hip Score (HHS). RESULTS: At a mean follow-up of 2.83 (1.0-7.7) years the mean wear was 0.82 mm (range 0.17-4.51, SD 0.50), and the wear-rate was 0.37 mm (range 0.06-1.90, SD 0.29). Wear-rate of 0.43 mm/year (SD 0.30) in cementless cups was higher (p = 0.004) than 0.30 mm/year (SD 0.27) in cemented cups. Mean age at time of surgery was 75.1 years (range 30-95). There was no correlation between age at time of surgery and wear (p = 0.56). There was no correlation between cup inclination and wear-rate (p = 0.35). TUG was mean 13.4 seconds (range 4.5-30.1) and correlated with wear rate (p = 0.03). CONCLUSIONS: At short term follow-up, the mean wear-rate in old and low demand patients was high, correlated to activity, and was above the generally accepted osteolysis threshold (0.1 mm/yr.). Cementless HA-coated cups had higher wear-rate than cemented cups.