Acta Orthopaedica最新文献

Background and purpose:  Metabolic syndrome (MetS) affects more than 60% of the patients having a hip or knee arthroplasty due to osteoarthritis. As it is debated whether metabolic syndrome increases the risk of complications, we aimed to investigate the length of stay (LOS) and risk of readmission at 30 and 90 days after surgery, including causes of readmission.

Methods:  We conducted a prospective cohort study of 2,901 patients undergoing hip and knee arthroplasty from May 2017 to November 2019. Physical examination, blood samples, and medical history from national registries determined the diagnosis of metabolic syndrome from the International Diabetes Federation definition. We used multivariate linear regression to investigate differences in LOS according to MetS, and binary regression to investigate the risk and causes of readmission within 30 and 90 days, including 95% confidence intervals (CI) and P values.

Results:  Patients with MetS showed a slightly longer LOS (0.20 days, CI 0.10-0.29) and had an increased risk of readmission within 90 days (adjusted relative risk [RR] 1.2, CI 1.0-1.4; P = 0.02), but not within 30 days (adjusted RR 1.1, CI 0.9-1.4; P = 0.3) after surgery. Cardiovascular disease was the dominant cause of readmission.

Conclusion: Although patients with MetS do not experience a clinically relevant longer LOS after hip and knee arthroplasty, they have an increased risk of 90-day readmission mainly due to cardiovascular complications, which should be considered when planning surgical care in this group of patients.

Background and purpose:  In contemporary total hip replacement (THR), dislocation is one of the most common complications. At our institution, the cause of an increase in the dislocation rate was recently reported to be reduced head coverage of a newly introduced neutral liner. We therefore aimed to ascertain whether differences exist in articulating head coverage between the various neutral liners used in contemporary THR. A secondary aim was to utilize coverage measurements to develop a new liner coverage classification.

Methods:  The articulating head coverage of 25 modular neutral polyethylene liners used in 6 uncemented cup designs from 4 major manufacturers was evaluated. The measurements were performed in a metrology laboratory and a mathematical model was developed to calculate coverage of the articulating surfaces. Further, 1 "elevated rim" liner and 1 "face changing liner" were included to develop a new liner coverage classification.

Results:  The articulating head coverage among the studied liners ranged from 167.7° to 194.8°, corresponding to a variation of 27.1°. The variations with different cup and head sizes within each design were smaller (from 1.0° to 5.6°) than those between different designs. Each of the liner designs offered distinct coverage, even though they were all classified as neutral. Based on measurements, a set of descriptive parameters to discriminate different liners in terms of coverage was created.

Conclusion:  We showed that all neutral liners are not equal - instead, they clearly varied in terms of their actual coverage design. We suggest our set of descriptive parameters called "hemispheric coverage index values" be used in discriminating the differences in liner coverage.

Background and purpose: We aimed to evaluate polyethylene (PE) wear, cup migration, and clinical outcome over 10 years in total hip arthroplasties (THA) using different articulations.

Methods:  This is a secondary analysis of 150 patients randomized into 5 groups, using different articulations: Charnley/Charnley Ogee for steel and conventional polyethylene (CPE), or Spectron EF/Reflection with either CPE or highly cross linked polyethylene (XLPE) cups, paired with heads made of either cobalt-chromium (CoCr) or oxidized zirconium (OxZr). All cups were cemented. Patients underwent repeated radiostereometric analysis (RSA) measurements for up to 10 years to assess wear and migration. Clinical outcome was assessed using Harris Hip Score (HHS).

Results:  After 10 years, the XLPE cups demonstrated low wear rates: 0.08 mm (95% confidence interval [CI] -0.11 to 0.26 mm) with CoCr heads and 0.06 mm (CI -0.14 to 0.26 mm) with OxZr heads, with a mean difference of 0.01 mm (CI -0.26 to 0.29 mm). In contrast, CPE cups exhibited significantly more wear: 1.35 mm (CI 1.16 to 1.55 mm) with CoCr heads and 1.68 mm (CI 1.44 to 1.92 mm) with OxZr heads, with a mean difference of 0.33 mm (CI 0.02 to 0.64 mm). The Charnley/Ogee group (CPE) showed PE wear of 0.34 mm (CI 0.12 to 0.56 mm). The CPE groups with OxZr and CoCr heads had 0.67 mm (CI 0.38 to 0.96 mm) and 0.35 mm (CI 0.09 to 0.61 mm) greater proximal migration respectively than the corresponding XLPE groups. HHS was similar across all groups.

Conclusion:  We found no significant advantage of OxZr over CoCr heads in reducing wear or migration. XLPE demonstrated a major reduction in wear as well as a reduction in cup migration compared with CPE. Charnley performed better than the other CPE cups in terms of PE wear and cup migration. No differences in clinical outcome were found.

Background and purpose:  Patients with external fixators are at risk of pin-site infection. A tool for objective monitoring of pin sites for evolving signs of infection is warranted. We aimed to investigate the temperature (MaxTp) difference between clean and visually inflamed pin sites using thermography and to establish the optimal cut-off value of MaxTp using thermography as a screening tool for inflammation detection.

Methods:  This was a cross-sectional study performed in the USA and Denmark of patients with circular external fixators. Pin sites were visually judged by a surgeon or a nurse as clean or as showing signs of inflammation. The MaxTp was obtained at the pin site by thermographic imaging using an infrared camera (FLIR T540).

Results:  We included 1,970 pin sites from 83 patients. The mean MaxTp for clean pin sites (n = 1,739) was 33.1°C (95% confidence interval [CI] 32.8-33.4) and the mean MaxTp for visual inflamed pin sites (n = 231) was 34.0°C (CI 33.6-34.3). The mean difference, when adjusted for repeated observations of patients and pin sites, was statistically significant with a difference of 0.9°C (CI 0.7-1.1) (P < 0.001). The area under the receiver operating characteristic curve for MaxTp as a screening tool to detect visual signs of inflammation was 0.71 (CI 0.65-0.76). The empirically optimal cut-off value was 34.1°C with a sensitivity of 65%, a specificity of 72%, a positive predictive value of 23%, and a negative predictive value of 94%.

Conclusion:  We found a statistically significant difference in mean temperature between pin sites with and without visual signs of inflammation. Thermography could be a promising tool for future point of care technology for monitoring inflammation around pin sites.

Background and purpose:  Fracture-related infections (FRIs) after osteosynthesis for hip fractures have not been thoroughly investigated. Our primary aim was to assess the association between FRIs and mortality after osteosynthesis for hip fracture. Secondary aims were to investigate the incidence, microbiology, and general epidemiological aspects of these FRIs.

Methods:  This retrospective single-center study included 1,455 patients > 18 years old with non-pathological hip fractures treated with osteosynthesis between 2015 and 2019. Medical records were reviewed and FRIs were diagnosed based on current consensus criteria. The follow-up period was 2 years. Mortality was estimated using Kaplan-Meier survival analysis. Cox regression analyses were performed to investigate the potential association between FRIs, as a time-dependent variable, and increased mortality.

Results: The median age for the entire cohort was 83 (interquartile range 75-89) years and 69% were females. At the 2-year follow-up mark, the crude mortality rate was 33% in the non-FRI group and 69% (11 of 16 patients) in the FRI group. Cox regression analysis assessing mortality risk revealed a hazard ratio of 3.5 (95% confidence interval [CI] 1.9-6.4) when adjusted for confounders. The incidence of FRI was 1.1% (16 of 1,455 patients). Staphylococcus aureus was the most common pathogen. Most FRI patients (94%) required at least 1 revision and 56% underwent ≥ 2 revision.

Conclusion:  We found an association between FRIs after hip fracture osteosynthesis and increased mortality, underscoring the critical need for FRI prevention measures in this frail patient group. The incidence and microbiological findings were consistent with previous studies.

Background and purpose: Healthcare systems globally are grappling with resource constraints and rising costs. Concerns have been raised about "low-value" care, which consumes healthcare resources without benefiting patients. We aimed to examine regional differences in common low-value musculoskeletal surgeries in Finland and explore explanatory factors behind the variation.

Methods: Using data from the Finnish Care Register for Health Care, surgeries conducted from 2006-2007 compared with 2020-2021 were analyzed across 20 hospital districts. Selected surgeries (acromioplasty, rotator cuff repair, partial meniscectomy, wrist arthroscopy, ankle arthroscopy, and distal radius fracture fixation) were categorized based on NOMESCO procedure codes, and incidence rates in older populations were calculated based on population size derived from Statistics Finland.

Results: We found substantial regional disparities in low-value surgeries. The incidence rates were higher in hospitals with high historical incidence rates and smaller population sizes, suggesting that the uptake of evidence is slower in small non-academic hospitals.

Conclusion: The incidence of low-value surgery is declining but regional differences remain large. It is unlikely that regional variation in disease incidence explains such large variation in low-value surgery. Instead, local treatment culture seems to be the driving force behind low-value surgery, and the practices seem to be more entrenched in small hospitals.