Mortality and subsequent fractures of patients with olecranon fractures compared to other upper extremity osteoporotic fractures.

Background: The incidence rate of olecranon fractures is highest in the elderly population. The aim of this study was to determine whether patients with olecranon fractures have similar demographic and risk characteristics compared to patients with osteoporotic upper extremity fractures. Methods: A retrospective data analysis was performed with diagnoses for olecranon fracture, distal radius fracture and proximal humerus fracture between 2014 and 2016. Results: A total of 157 olecranon, 1022 distal radius and 451 proximal humerus fractures were identified. The risk of mortality after olecranon and distal radius fractures was comparable but statistically significantly higher after proximal humerus fractures (HR 1.97, 95% CI 1.19-3.27). The risk of subsequent osteoporotic fractures after an olecranon fracture was 10% at 1 year and 14% at 5 years and the risks did not differ statistically after a proximal humerus fracture, 6% and 11% (HR 0.65, 95% CI 0.40-1.06). After a distal radius fracture, the risks were statistically significantly lower: 2% and 5% (HR 0.35, 95% CI 0.22-0.56). Discussion: Patients with olecranon fractures have essentially similar demographic characteristics compared to patients with distal radius fractures, but the probability for a subsequent fracture is significantly higher and more comparable to patients with proximal humerus fractures.

Radiological outcome of hallux valgus deformity correction with metatarsal osteotomy from a single-center cohort - Best results achieved by foot and ankle surgeons.

BACKGROUND: To evaluate the radiological outcome, especially undercorrection of hallux valgus deformity correction with first metatarsal osteotomy. PATIENTS AND METHODS: 439 1st metatarsal osteotomies including 241 distal (55 %), 175 midshaft (40 %), and 23 proximal (5 %) were available for analysis with median follow-up time was 48 days (range 27-990 days). RESULTS: The postoperative HVA was normal in 237 (54 %), mild in 110 (25 %), moderate in 87 (20 %), and severe in 5 (1 %) of the cases. BMI (p = 0.0127), sex (p = 0.0004), preoperative HVA (p = 0.0028), and surgeons experience (p < 0.0001) were associated with radiological outcome, whereas age, hospital, and type of osteotomy had no effect. Foot and ankle surgeons achieved normal postoperative HVA in 76 %, general orthopedic surgeons in 41 %, and residents in 47 % of the operations. CONCLUSION: Radiological undercorrection was common. As foot and ankle surgeons achieved best radiological correction, hallux valgus deformity should be operated by specialists.

Anterior cruciate ligament reconstruction and concomitant procedures in Finland between 2004 and 2018 based on national registers.

BACKGROUND AND PURPOSE: We aimed to assess the incidence of anterior cruciate ligament reconstruction (ACLR) and concomitant procedures in Finland. PATIENTS AND METHODS: We identified all the patients who underwent ACLR between 2004 and 2018 in Finland using national registry data. Patients with an ICD-10 diagnosis code S83.5 and the NOMESCO operation codes NGE30 or NGE35 were included. We recorded the patient's age, sex, Charlson comorbidity index, and concomitant procedures. NGE30 or NGE35 was defined as the main procedure and all other procedures attached to this procedure were included as concomitant procedures. RESULTS: Our study included 37,224 ACLRs. The overall incidence of ACLR was 46 (95%CI 34-62) per 105 person-years. This increased from 38 per 105 person-years in 2004 to its peak of 53 in 2014 before decreasing to 47 by 2018. Male patients had a higher overall incidence of ACLR than female patients (61 [CI 47-78] vs. 32 [CI 22-45] per 105 person-years, respectively). However, this difference changed over time: for the males, a decrease in ACLR incidence was observed after 2014, whereas for the females, the trend increased throughout the study period. For both sexes, the highest incidence of ACLRs was in the age group 16-29 years (159 and 71 per 105 person-years, respectively). Concomitant procedures were performed at the time of ACLR in 32% of cases. CONCLUSION: While the total incidence of ACLR decreased slightly from 2014 to 2018, it increased among women over the full study period, which might be due to increased female participation in contact sports. Special attention should be given to girls' and women's ACL rupture prevention and treatment.

Incidence and Treatment Trends of Achilles Tendon Ruptures in Finland: A Nationwide Study.

Background: Global reports indicate rising Achilles tendon rupture (ATR) incidence. In recent decades, the optimal treatment for this injury has been widely studied. Alongside the cumulating comparative evidence regarding the optimal method of treatment, nonoperative treatment has increased in popularity compared with operative treatment. Purpose: To determine the current incidence of ATRs and their treatment in Finland and how these have changed from 1997 to 2019. Study Design: Descriptive epidemiology study. Methods: Two national registers (the National Hospital Discharge Register and the Finnish Register of Primary Health Care Visits) were used to identify all ATR cases and operations to treat them; the incidence was calculated based on the annual adult population size. Results: During the study period, ATR incidence increased from 17.3 to 32.3 per 100,000 person-years. The increase in incidence seemed to plateau starting in the second half of the study period. The rise in ATR incidence occurred in both sexes and all age groups but most markedly among the elderly. The incidence of operative treatment decreased from 13.6 to 4.9 per 100,000 person-years. This decline was observed from 2008 onward and in all age groups. Conclusion: The incidence of ATRs increased and the use of operative treatment decreased. The decreasing trend of operative treatment is in line with other international reports and resonates with the current literature about the optimal treatment of ATRs.

Median 10-year whole blood metal ion levels and clinical outcome of ReCap-M2a-Magnum metal-on-metal total hip arthroplasty.

BACKGROUND AND PURPOSE: We have previously reported that the whole blood (WB) chromium (Cr) and cobalt (Co) ion levels decrease in the short term after ReCap-M2a-Magnum large-diameter head (LDH) metal-on-metal (MoM) total hip arthroplasty (THA). This study reports long-term metal ion levels and clinical outcomes after ReCap-Magnum THA. PATIENTS AND METHODS: ReCap-M2a-Magnum LDH THA was used in 1,450 patients in our hospital district from 2005 to 2012. Median follow-up time was 10 years. 991 patients had 2 or more metal ion measurements. The median measurement interval was 4 years. Individual metal ion change was assessed using logarithmic metal ion values in a random coefficient model. Kaplan-Meier survival estimates were calculated for revision surgery for any reason for revision, and separately for metal-related adverse events (metal ions above safe upper limit [SUL], revision due to ARMD, or pseudotumor). RESULTS: Geometric mean of Cr decreased from 1.8 ppb (geometric standard deviation [GSD] 1.8) to 1.0 ppb (GSD 2.8, p < 0.001). The Co levels decreased from 1.7 ppb (GSD 2.4) to 1.4 ppb (GSD 2.8, p < 0.001). The hip-specific survival was 85% for revision due to any reason at 14 years and the hip-specific survival for any metal-related adverse event was 69% at 14 years. INTERPRETATION: WB Cr and Co levels continued to decrease in the long-term follow-up of ReCap-M2a-Magnum THA patients. The amount of metal-related adverse events was rather high, but revision surgery was seldom required. We suggest that after 10 years from the implantation a 5-year measurement interval may be sufficient for asymptomatic ReCap-M2a-Magnum patients.

Scandinavian Olecranon Research in the Elderly (SCORE): protocol for a non-inferiority, randomised, controlled, multicentre trial comparing operative and conservative treatment of olecranon fractures in the elderly.

INTRODUCTION: The incidence of olecranon fractures is growing in the elderly population. The traditional operative approach is giving way among the elderly to conservative treatment, which seems to provide a comparable functional outcome with a lower complication burden. However, there is still a lack of reliable evidence to support this shift.The objective of this trial is to investigate whether conservative treatment of displaced olecranon fractures in patients aged 75 or older yields comparable results to those of operative treatment in terms of pain and daily function. METHODS AND ANALYSIS: Scandinavian Olecranon Research in the Elderly (SCORE) is a randomised, controlled, multicentre, non-inferiority trial. Eligible patients will be randomised to either conservative or operative treatment. The sample size will be 68 patients and allocation done at a 1:1 ratio (34 patients per group). The randomisation is stratified according to the participating hospital and patient's sex. Both groups will receive the same postoperative physiotherapy and pain management. The primary outcome is Disabilities of the Arm, Shoulder and Hand at 1-year follow-up. Secondary outcomes are pain and satisfaction measured on visual analogue scales, Patient Reported Elbow Evaluation, range of motion of the elbow and extension strength of the elbow compared with the unaffected arm. Radiographs will be taken at each follow-up. Primary analysis of the results will be conducted on an intention-to-treat basis. ETHICS AND DISSEMINATION: The study protocol for this clinical trial has been approved by the Ethics Committee of the Hospital District of Southwest Finland and will be submitted for approval to the Regional Ethics Committees in Linköping, Sweden and Copenhagen, Denmark. Every recruiting centre will apply local research approvals. The results of this study will be submitted for publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04401462. PROTOCOL VERSION: This is the second protocol version dated on 16 April 2020.

Long-term blood metal ion levels and clinical outcome after Birmingham hip arthroplasty.

BACKGROUND AND OBJECTIVE: Our aim was to assess long-term metal ion level changes and clinical outcome in patients with a Birmingham hip arthroplasty. METHODS: For the purpose of this study, we identified all BHR hip resurfacing arthroplasty (HRA) and total hip arthroplasty (THA) operations performed in Turku University Hospital. A random coefficient model was used to compare the change between the first and last metal ion measurement. A Kaplan-Meier estimator was used to assess the survivorship of the BHR HRA and BHR THA with metal related adverse events (pseudotumor, elevated metal ions above the safe upper limit, revision due to metallosis), or revision due to any reason as endpoints with 95% confidence intervals (CIs). RESULTS: BHR HRA was used in 274 hips (233 patients). In addition, we identified 38 BHR-Synergy THAs (38 patients). Operations were performed between 2003 and 2010. Median follow-up time was 14 years for BHR HRA (range: 0.6-17) and 11 years for BHR THA (range: 4.7-13). In the BHR HRA group, geometric means of Cr and Co levels decreased from 2.1 to 1.6 ppb and 2.4 to 1.5 ppb, respectively, during a 3.0-year measurement interval. Metal ion levels in the BHR THA group did not show notable increase. The survivorship of BHR HRA was 66% in 16 years and 34% for BHR THA at 12 years for any metal-related adverse event. CONCLUSIONS: Patients with a Birmingham hip device do not seem to benefit from frequent repeated metal ion measurements. The amount of patients with metal-related adverse events was relatively high, but many of them did not require surgery.

Repeated metal ion measurements and long-term outcome of Durom/MMC total hip arthroplasty.

Background and purpose - Data regarding long-term behavior of metal ion levels in metal-on-metal total hip arthroplasty (MoM THA) patients is scarce. Therefore, we assessed whether there is any change in whole blood (WB) chromium (Cr), and cobalt (Co) ion measurements in Durom and MMC MoM THA patients over time. The secondary aim was to report the clinical outcomes using these devices in a single district. Patients and methods - Durom and MMC cups were used in 249 MoM THAs from 2005 to 2011 in our district. Median follow-up time was 12 years for Durom THA (interquartile range [IQR] = 3) and 9 years for MMC THA (IQR = 1). A random coefficient model was used to compare individual differences in repeated WB Cr and Co ion measurements. The Kaplan-Meier estimator was used to analyze implant survival with any reason for revision as the endpoint. Results - Geometric means of Cr in Durom THA and MMC THA patients decreased from 2.2 ppb (geometric standard deviation [SD] = 1.9) to 1.5 ppb (geometric SD = 2.5, p< 0.001) and from 1.8 ppb (geometric SD = 1.8) to 1.1 ppb (geometric SD = 2.8, p = 0.01) respectively. The geometric means of Co values remained unchanged. The 10-year survival of Durom THA was 82%, and that of MMC THA 89% for any revision reason as endpoint. Interpretation - WB Cr levels decreased over time, and Co levels remained unchanged at long-term follow-up. Despite this we recommend continuing the follow-up of these devices due to relatively low implant survival.

Functional results of total-knee arthroplasty versus medial unicompartmental arthroplasty: two-year results of a randomised, assessor-blinded multicentre trial.

OBJECTIVE: The primary objective of the trial was to assess the clinical effectiveness of medial unicompartmental knee arthroplasty versus total knee arthroplasty in patients with isolated medial osteoarthritis of the knee. DESIGN: Prospective, randomised, 2 years, assessor-blind, multicentre, superiority trial. SETTING: The patients were enrolled between December 2015 and May 2018 from the outpatient clinics of three public high-volume arthroplasty hospitals (Finland). PARTICIPANTS: We recruited 143 patients with symptomatic-isolated medial osteoarthritis of the knee needing an arthroplasty procedure. All the patients were suitable for both unicompartmental and total knee arthroplasties. Population was selected as the end-stage-isolated medial osteoarthritis. INTERVENTIONS: All patients, randomized 1:1, received a medial unicompartmental arthroplasty or a total knee arthroplasty through a similar midline skin incision. Patients were blinded to the type of arthroplasty for the whole 2 years of follow-up. MAIN OUTCOME MEASURES: Primary outcome measure was between-group differences in the Oxford Knee Score (OKS) and secondary outcome Knee injury and Osteoarthritis Score (KOOS) at 2 years postoperatively. The changes within and between the groups were analysed with analysis of variance for repeated measurements. RESULTS: The primary outcome was comparable for medial unicompartmental arthroplasty and total knee arthroplasty at 2 years. The mean difference in the OKS between the groups was 1.6 points (95% CI -0.7 to 3.9). In the KOOS subscales, the mean difference between the groups was 0.1 points (95% CI -4.8 to 5.0) for pain, 7.8 points (95% CI 1.5 to 14.0) for symptoms, 4.3 points (95% CI -0.6 to 9.2) for function in daily living, 4.3 points (95% CI -3.0 to 11.6) for function in sports, and 2.1 points (95% CI -4.8 to 9.1) for knee-related quality of life. CONCLUSIONS: The recovery after unicompartmental knee arthroplasty was faster compared with total knee arthroplasty, but unicompartmental arthroplasty did not provide a better patient-reported outcome at 2 years. TRIAL REGISTRATION NUMBER: NCT02481427.

Preoperative Posterior Tilt Increases the Risk of Later Conversion to Arthroplasty After Osteosynthesis for Femoral Neck Fracture.

BACKGROUND: Femoral neck fractures (FNFs) are one of the most common injuries in the elderly. Treatment is either internal fixation or primary arthroplasty. The main aim of this study is to assess the risk factors associated with fixation failure leading to further arthroplasty in FNFs treated with cannulated screws. METHODS: Data on internal fixations of FNFs performed at Turku University Hospital between January 1, 2012 and December 31, 2017 were collected retrospectively from the patient database. Radiographical measurements were performed for preoperative displacement and posterior tilt, postoperative displacement, reduction quality, and implant shaft angle. RESULTS: Altogether 301 cases were included in the study. The overall reoperation rate was 25% and conversion to arthroplasty was performed in 16% of cases. In the multiple variant analysis, adjusted for age and gender, nondisplaced fractures with a 0°-20° preoperative posterior tilt had a significantly lower risk of later conversion to arthroplasty than did nondisplaced fractures with a ≤0° or ≥20° posterior tilt (odds ratio [OR] 4.0, 95% confidence interval [Cl] 1.8-8.6, P = .0005) and displaced fractures (OR 7.2, 95% CI 3.0-17.4, P < .0001). No statistically significant association was found between preoperatively nondisplaced fractures with a <0° or ≥20° posterior tilt and displaced fractures (OR 0.6, 95% Cl 0.2-1.3, P = .2). CONCLUSION: Displaced fractures and fractures with a preoperative posterior tilt of <0° or ≥20° have a considerably increased risk of reoperation and conversion to arthroplasty. Primary arthroplasty should be considered as treatment for displaced FNFs and fractures with >20° or <0° posterior tilt, especially in fragile patients, to avoid further operations.

Effect of lumbar laminectomy on spinal sagittal alignment: a systematic review.

PURPOSE: Positive spinal sagittal alignment is known to correlate with pain and disability. The association between lumbar spinal stenosis and spinal sagittal alignment is less known, as is the effect of lumbar decompressive surgery on the change in that alignment. The objective was to study the evidence on the effect of lumbar decompressive surgery on sagittal spinopelvic alignment. METHODS: The Cochrane Controlled Trials Register (CENTRAL), Medline, Embase, Scopus and Web of Science databases were searched in October 2019, unrestricted by date of publication. The study selection was performed by two independent reviewers. The risk of systematic bias was assessed according to the NIH Quality Assessment Tool. The data were extracted using a pre-defined standardized form. RESULTS: The search resulted in 807 records. Of these, 18 were considered relevant for the qualitative analysis and 15 for the meta-synthesis. The sample size varied from 21 to 89 and the average age was around 70 years. Decompression was mostly performed on one or two levels and the surgical techniques varied widely. The pooled effect sizes were most statistically significant but small. For lumbar lordosis, the effect size was 3.0 (95% CI 2.2 to 3.7) degrees. Respectively, for pelvic tilt and sagittal vertical axis, the effect sizes were - 1.6 (95% CI .2.6 to - 0.5) degrees and - 9.6 (95% CI - 16.0 to - 3.3) mm. CONCLUSIONS: It appears that decompression may have a small, statistically significant but probably clinically insignificant effect on lumbar lordosis, sagittal vertical axis and pelvic tilt.

Complications and reoperations related to tension band wiring and plate osteosynthesis of olecranon fractures.

BACKGROUND: Olecranon fractures are common and usually treated operatively either by tension band wiring (TBW) or plate fixation (PF). The aim of this study was to assess early complications and reoperations and their predictive factors related to those operative methods. METHODS: A retrospective analysis of all patients with an operatively treated olecranon fracture between 2007 and 2017 at Turku University hospital was performed. Reoperations, postoperative complications, and potential risk factors for these were recorded. RESULTS: A total of 434 patients (387 TBW and 47 PF) were identified. There was no statistically significant difference in the rate of early complications (49% vs. 62%, P = .262) or reoperations (38% vs. 53%, P = .079) between patients treated with TBW and PF. In the TBW group, the intramedullary placement of Kirschner (K)-wires predisposed patients to complications compared to transcortical placement of the K-wires according to multivariate analysis (odds ratio [OR] 1.94, P = .026). Younger age was associated with the frequency of reoperations, the odds decreasing 24% for every 10 years of age (P < .001). Further, patients with high-energy trauma mechanisms were reoperated more often compared to patients with low-energy trauma (OR 2.99, P = .002). Also, excellent postoperative reduction was associated with higher reoperation rate than good or fair reduction (OR 0.48, P = .033). CONCLUSION: There is a high risk of early complications and reoperations associated to both TBW and PF. Transcortical positioning of K-wires may reduce the rate of complications in TBW.

Implant survival of 2,723 vitamin E-infused highly crosslinked polyethylene liners in total hip arthroplasty: data from the Finnish Arthroplasty Register.

Background and purpose - The use of crosslinked polyethylene in total hip arthroplasty (THA) has decreased wear remarkably. It has been suggested that the antioxidative effects of vitamin E may enhance the wear properties of polyethylene even further. This study evaluates revision rates between vitamin E-infused polyethylene liners (E1 and E-poly, ZimmerBiomet, Warsaw, IN, USA) versus moderately crosslinked polyethylene (ModXLPE) liners from the same manufacturer used in primary THA.Patients and methods - We conducted a study based on data from the Finnish Arthroplasty Register. The study group consisted of 2,723 THAs with a vitamin E-infused liner and a reference group of 2,707 THAs with a moderately crosslinked polyethylene liner. Survivorship, revision risk, and re-revision causes were compared between groups.Results - The 7-year survival of the vitamin E-infused polyethylene liner group and of the reference group with revision for any reason as the endpoint was comparable (94% [95% CI 92.9-94.9] and 93% [CI 91.9-93.9], respectively). The adjusted hazard ratio (HR) for any revision was similar between the groups (0.7 [CI 0.4-1.1]). When revision for aseptic loosening was studied as the endpoint, the survival for the study group was 99% (CI 98.6-99.4) and for the reference group 99% (CI 98.7-99.5), and the risk of revision was comparable between the study groups (HR 1.3 [CI 0.7-2.5]).Interpretation - After an observation period of 7 years vitamin E-infused liners shows results equal to results obtained with crosslinked polyethylene liners.

Progression of adverse local tissue reaction in ASR metal-on-metal hip arthroplasty: a longitudinal MARS-MRI study at mid- to long-term.

BACKGROUND: Despite the large number of studies assessing adverse local tissue reaction (ALTR) in metal-on-metal (MoM) hip implants, there is still a lack of knowledge about the natural progression of ALTR. The aims of this study were to describe the natural course of changes in ALTR at mid- to long-term follow-up for patients treated with metal-on-metal hip arthroplasty and to determine possible risk factors associated with change in ALTR. METHODS: A total of 158 patients (158 hips), 109 MoM hip resurfacing arthroplasties (HRAs) and 49 MoM total hip arthroplasties (THAs), with 2 clinical follow-ups including MARS-MRIs were included. The mean time from index operation to the first visit was 7.6 years (range 3.4-11.4 years), and the mean time between the 2 visits was 1.0 year (range 0.7-1.6 years). RESULTS: The proportion of patients with moderate or severe ALTR did not increase significantly between the first and second visit for the MoM HRA group (14.7-15.6%; p = 0.850) or the MoM THA group (32.7-36.7%; p = 0.671). 8 (7.3%) HRA patients and 9 (18.4%) THA patients progressed in ALTR grade. None of the collected clinical variables was sensitive or specific in identifying patients with ALTR progression. CONCLUSIONS: Although ALTR prevalence was high in our cohort, clinically significant ALTR progression was rare. We were unable to find any predictors associated with ALTR change. This indicates that MARS-MRI remains a valuable tool in the follow-up of patients treated with MoM hip devices in identifying patients who may need revision surgery.

Posterior approach, fracture diagnosis, and american society of anesthesiology class iii-iv are associated with increased risk of revision for dislocation after total hip arthroplasty: An analysis of 33,337 operations from the finnish arthroplasty register.

BACKGROUND AND OBJECTIVE: Dislocation is one of the most common reasons for revision surgery after primary total hip arthroplasty. Both patient related and surgical factors may influence the risk of dislocation. In this study, we evaluated risk factors for dislocation revision after total hip arthroplasty based on revised data contents of the Finnish Arthroplasty Register. METHODS: We analyzed 33,337 primary total hip arthroplasties performed between May 2014 and January 2018 in Finland. Cox proportional hazards regression was used to estimate hazard ratios with 95% confidence intervals for first dislocation revision using 18 potential risk factors as covariates, such as age, sex, diagnosis, hospital volume, surgical approach, head size, body mass index, American Society of Anesthesiology class, and fixation method. RESULTS: During the study period, there were 264 first-time revisions for dislocation after primary total hip arthroplasty. The hazard ratio for dislocation revision was 3.1 (confidence interval 1.7-5.5) for posterior compared to anterolateral approach, 3.0 (confidence interval 1.9-4.7) for total hip arthroplasties performed for femoral neck fracture compared to total hip arthroplasties performed for osteoarthritis, 2.0 (confidence interval 1.0-3.9) for American Society of Anesthesiology class III-IV compared to American Society of Anesthesiology class I, and 0.5 (0.4-0.7) for 36-mm femoral head size compared to 32-mm head size. CONCLUSIONS: Special attention should be paid to patients with fracture diagnoses and American Society of Anesthesiology class III-IV. Anterolateral approach and 36-mm femoral heads decrease dislocation revision risk and should be considered for high-risk patients.

Does cup position differ between trabecular metal and titanium cups? A radiographic propensity score matched study of 300 hips.

Background and purpose - The use of trabecular metal cups in primary total hip arthroplasty (THA) is increasing, despite the survival of Continuum cups being slightly inferior compared with other uncemented cups in registries. This difference is mainly explained by a higher rate of dislocation revisions. Cup malpositioning is a risk factor for dislocation and, being made of a highly porous material, Continuum cups might be more difficult to position. We evaluated whether Continuum cups had worse cup positioning compared with other uncemented cups. Patients and methods - Based on power calculation, 150 Continuum cups from 1 center were propensity score matched with 150 other uncemented cups from 4 centers. All patients had an uncemented stem, femoral head size of 32 mm or 36 mm, and BMI between 19 and 35. All operations were done for primary osteoarthrosis through a posterior approach. Patients were matched using age, sex, and BMI. Cup positioning was measured from anteroposterior pelvic radiograph using the Martell Hip Analysis Suite software. Results - There was no clinically relevant difference in mean inclination angle between the study group and the control group (43° [95% CI 41-44] and 43° [CI 42-45], respectively). The study group had a larger mean anteversion angle compared with the control group, 19° (CI 18-20) and 17° (CI 15-18) respectively. Interpretation - Continuum cups had a greater anteversion compared with the other uncemented cups. However, the median anteversion was acceptable in both groups and this difference does not explain the larger dislocation rate in the Continuum cups observed in earlier studies.

Implant Survival of 6,080 Tritanium Cups in Primary Total Hip Arthroplasty: Data from the Finnish Arthroplasty Register from 2009 to 2017.

BACKGROUND: To enhance osseointegration in total hip arthroplasty (THA), ultraporous or highly porous-coated cups were introduced. Implant survival data on these new devices have been scarce. The aim of our study was to assess the survivorship of ultraporous Tritanium cups (Stryker) in a population-based register study. METHODS: In this study, we collected data on 6,080 primary THAs using a Tritanium cup and 25,670 THAs using a conventional cup (control group) from the Finnish Arthroplasty Register; these procedures were performed from January 1, 2009, to December 31, 2017. We calculated the Kaplan-Meier survival estimates with 95% confidence intervals (CIs). The end point was revision for any reason or for aseptic loosening of the cup. The revision risks were assessed with use of the Cox multiple regression model. The variables assessed in the Cox model were femoral head size, age group, involved side, operation year, sex, diagnosis, and fixation of the stem. The proportional hazards assumption of the Cox model was not fulfilled, so the follow-up time was divided into 3 time periods: 0 to 2 years, >2 to 4 years, and >4 years. RESULTS: When comparing the 2 groups with regard to revision for any reason, the 5-year Kaplan-Meier survivorship of the Tritanium group (94.7% [95% CI, 94.0% to 95.4%]) was inferior to that of the control group (96.0% [95% CI, 95.7% to 96.3%]). In the Cox regression analysis of the 2 groups for the time period of >4 years, the Tritanium group had an increased risk of revision for any reason compared with the control group (hazard ratio [HR], 3.12 [95% CI, 1.82 to 5.35]; p < 0.001). With regard to revision for aseptic loosening of the cup, the Tritanium group had an increased risk of revision compared with the control group for both 0 to 2 years (HR, 3.80 [95% CI, 1.76 to 8.24]; p < 0.001) and >2 to 4 years (HR, 11.2 [95% CI, 3.28 to 38.0]; p < 0.001). CONCLUSIONS: There was no advantage to using the ultraporous-coated Tritanium cup for primary THA compared with conventional uncemented cups. However, wide CIs for some HR estimates may point to a lack of precision. Therefore, further research on subject is needed. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Obesity is not associated with hip failure in patients with articular surface replacement of the hip.

BACKGROUND: Our main aim was to investigate whether obese patients were at increased risk of elevated metal ion levels and/or adverse local tissue reaction (ALTR) after being treated with articular surface replacement (ASR) hip arthroplasty. METHODS: This study included 360 patients who underwent metal-on-metal (MoM) hip resurfacing (HRA) or total hip arthroplasty (THA). 95 patients (26%) were underweight/normal weight (BMI < 25 kg/m2), 139 (39%) were overweight (BMI 25-30 kg/m2), and 126 (36%) were obese (BMI ⩾ 30 kg/m2). Blood metal ion levels and patient-reported outcome measures (PROMs) were obtained, and a sub-cohort of 85 patients had MARS MRI performed. Logistic regression analyses were used to assess the associations between obesity and metal ions, as well as ALTR. RESULTS: BMI was not associated with either elevated metal ion levels or ALTR. In HRA patients, female gender (OR 3.0; p = 0.019) and pain (OR 2.3; p = 0.046) were associated with elevated Co levels. Female patients had increased risk of elevated Cr levels (OR 3.0; p = 0.02). In THA patients, female gender (OR 2.2; p = 0.004) and VAS satisfaction (OR 2.1; p = 0.01) were associated with elevated Co levels. Female gender (OR 3.6; p = 0.001) and time from surgery (OR 1.4; p = 0.005) were associated with Cr levels. In the sub-cohort, ALTR was associated with Co levels (OR 16.1; p = 0.002) in HRA patients. CONCLUSION: Patients with BMI ⩾ 30 kg/m2 present no increased risk for elevated metal ion levels or development of ALTR.

Implant Survival of Constrained Acetabular Device in Primary Total Hip Arthroplasty Based on Data From the Finnish Arthroplasty Register.

BACKGROUND: Constrained acetabular devices were developed to prevent dislocations after total hip arthroplasty (THA). However, the data on their success have been contradictory. In this study, we aimed to assess implant survival of the constrained acetabular device in primary THA based on the Finnish Arthroplasty Register data. METHODS: A total of 373 primary THAs with constrained acetabular devices inserted from 2006 to 2017 were included. A reference group was formed on a 1:3 basis and matched for age, sex, and diagnosis, consisting of 1118 conventional THAs. Implant survival estimates using death as a competing risk were assessed with revision for any reason and for any aseptic reason as the endpoints. The Cox multiple regression models were adjusted for age, sex, and diagnosis. The mean follow-up time was 3.3 (0-12.4) years for the constrained device group and 3.8 (0-12.0) years for the reference group. RESULTS: Overall, there were 21 revisions in the constrained device group and 49 in the reference group. The 8-year survivorship for any reason was 94% (confidence interval [CI]: 91-96) for the constrained device group and 93% (CI: 89-97) for the reference group. With revision for any aseptic reason as the endpoint, the 8-year survivorships were 97% (CI: 95-99) and 94% (CI: 90-98), respectively. During the first 1.5 years, the constrained acetabular device group had a similar revision risk (hazard ratio: 1.09 [CI: 0.57-2.07], P = .8) to that of the reference group. CONCLUSION: The constrained acetabular device had good survival in primary THA, and our results support its continued use even in high-risk patients.

Survival of 11,390 Continuum cups in primary total hip arthroplasty based on data from the Finnish Arthroplasty Register.

Background and purpose - The use of trabecular metal (TM) cups for primary total hip arthroplasty (THA) is increasing. Some recent data suggest that the use of TM in primary THA might be associated with an increased risk of revision. We compared implant survival of Continuum acetabular cups with other commonly used uncemented cups. Patients and methods - Data on 11,390 primary THAs with the Continuum cup and 30,372 THAs with other uncemented cups (reference group) were collected from the Finnish Arthroplasty Register. Kaplan-Meier survival estimates were calculated; the endpoint was revision for any reason, for infection, or for dislocation. Revision risks were assessed with adjusted Cox multiple regression models. A subgroup analysis on the use of neutral or elevated liners in the Continuum group was made. Results - The 7-year survivorship of the Continuum group was 94.6% (95% CI 94.0-95.2) versus 95.6% (CI 95.3-95.8) in the reference group for revision for any reason. The risk for revision was higher in the Continuum group than in the reference group both for revision for any reason (HR 1.3 [CI 1.2-1.5)]) and for revision for dislocation (HR 1.9 [CI 1.5-2.3]). There was no difference in the rates of revision because of infection (HR 0.99 [CI 0.78-1.3]). Use of a neutral liner increased the risk for revision due to dislocation in comparison with the use of an elevated rim liner in the Continuum group (HR 1.7 [CI 1.2-2.5]). Interpretation - THA with Continuum cups is associated with an increased risk of revision compared with other uncemented cups, mainly due to revisions because of dislocation. Our results support the use of an elevated liner when Continuum cups are used for primary THA.