Patients in high- and low-revision hospitals have similar outcomes after primary knee arthroplasty: 1-year postoperative results from the Danish prospective multicenter cohort study, SPARK.

PURPOSE: It is well-known that revision rates after primary knee arthroplasty vary widely. However, it is uncertain whether hospital revision rates are reliable indicators of general surgical quality as defined by patients. The SPARK study compared primary knee arthroplasty surgery at three high-volume hospitals whose revision rates differed for unknown reasons. METHODS: This prospective observational study included primary knee arthroplasty patients (total, medial/lateral unicompartmental and patellofemoral) in two low-revision hospitals (Aarhus University Hospital and Aalborg University Hospital Farsø) and one high-revision hospital (Copenhagen University Hospital Herlev-Gentofte). Patients were followed from preoperatively (2016-17) to 1-year postoperatively with patient-reported outcome measures including Oxford Knee Score (OKS), EQ-5D-5L and Copenhagen Knee ROM (range of motion) Scale. The surgical outcomes were compared across hospitals for patients with comparable grades of radiographic knee osteoarthritis and preoperative OKS. Statistical comparisons (parametric and non-parametric) included all three hospitals. RESULTS: 97% of the 1452 patients who provided baseline data (89% of those included and 56% of those operated) responded postoperatively (90% at 1 year). Hospitals' utilization of unicompartmental knee arthroplasties differed (Aarhus 49%, Aalborg 14%, and Copenhagen 22%, p < 0.001). 28 patients had revision surgery during the first year (hospital independent, p = 0.1) and were subsequently excluded. 1-year OKS (39 ± 7) was independent of hospital (p = 0.1), even when adjusted for age, sex, Body Mass Index, baseline OKS and osteoarthritis grading. 15% of patients improved less than Minimal Important Change (8 OKS) (Aarhus 19%, Aalborg 13% and Copenhagen 14%, p = 0.051 unadjusted). Patients with comparable preoperative OKS or osteoarthritis grading had similar 1-year results across hospitals (OKS and willingness to repeat surgery, p ≥ 0.087) except for the 64 patients with Kellgren-Lawrence grade-4 (Aarhus 4-6 OKS points lower). 86% of patients were satisfied, and 92% were "willing to repeat surgery", independent of hospital (p ≥ 0.1). Hospital revision rates differences diminished during the study period. CONCLUSIONS: Patients in hospitals with a history of differing revision rates had comparable patient-reported outcomes 1 year after primary knee arthroplasty, supporting that surgical quality should not be evaluated by revision rates alone. Future studies should explore if revision rate variations may depend as much on revision thresholds and indications as on outcomes of primary surgery. LEVEL OF EVIDENCE: Level II (Prospective cohort study).

Hospital variation in revision rates after primary knee arthroplasty was not explained by patient selection: baseline data from 1452 patients in the Danish prospective multicenter cohort study, SPARK.

PURPOSE: Revision rates following primary knee arthroplasty vary by country, region and hospital. The SPARK study was initiated to compare primary surgery across three Danish regions with consistently different revision rates. The present study investigated whether the variations were associated with differences in the primary patient selection. METHODS: A prospective observational cohort study included patients scheduled Sep 2016 Dec 2017 for primary knee arthroplasty (total, medial/lateral unicompartmental or patellofemoral) at three high-volume hospitals, representing regions with 2-year cumulative revision rates of 1, 2 and 5%, respectively. Hospitals were compared with respects to patient demographics, preoperative patient-reported outcome measures, motivations for surgery, implant selection, radiological osteoarthritis and the regional incidence of primary surgery. Statistical tests (parametric and non-parametric) comprised all three hospitals. RESULTS: Baseline data was provided by 1452 patients (89% of included patients, 56% of available patients). Patients in Copenhagen (Herlev-Gentofte Hospital, high-revision) were older (68.6 ± 9 years) than those in low-revision hospitals (Aarhus 66.6 ± 10 y. and Aalborg (Farsø) 67.3 ± 9 y., p = 0.002). In Aalborg, patients who had higher Body Mass Index (mean 30.2 kg/m2 versus 28.2 (Aarhus) and 28.7 kg/m2 (Copenhagen), p < 0.001), were more likely to be male (56% versus 45 and 43%, respectively, p = 0.002), and exhibited fewer anxiety and depression symptoms (EQ-5D-5L) (24% versus 34 and 38%, p = 0.01). The preoperative Oxford Knee Score (23.3 ± 7), UCLA Activity Scale (4.7 ± 2), range of motion (Copenhagen Knee ROM Scale) and patient motivations were comparable across hospitals but varied with implant type. Radiological classification ≥ 2 was observed in 94% (Kellgren-Lawrence) and 67% (Ahlbäck) and was more frequent in Aarhus (low-revision) (p ≤ 0.02), where unicompartmental implants were utilized most (49% versus 14 (Aalborg) and 23% (Copenhagen), p < 0.001). In the Capital Region (Copenhagen), the incidence of surgery was 15-28% higher (p < 0.001). CONCLUSION: Patient-reported outcome measures prior to primary knee arthroplasty were comparable across hospitals with differing revision rates. While radiographic classifications and surgical incidence indicated higher thresholds for primary surgery in one low-revision hospital, most variations in patient and implant selection were contrary to well-known revision risk factors, suggesting that patient selection differences alone were unlikely to be responsible for the observed variation in revision rates across Danish hospitals. LEVEL OF EVIDENCE: II, Prospective cohort study.

Measurement properties of UCLA Activity Scale for hip and knee arthroplasty patients and translation and cultural adaptation into Danish.

Background and purpose - The UCLA Activity Scale (UCLA) is a questionnaire assessing physical activity level from 1 (low) to 10 (high) in patients undergoing hip or knee arthroplasty (HA/KA). After translation and cultural adaptation, we evaluated the measurement properties of the Danish UCLA.Patients and methods - After dual panel translation, cognitive interviews were performed among 55 HA/KA patients. An orthopedic surgeon and a physiotherapist estimated UCLA scores for 80 KA patients based on short interviews. Measurement properties were evaluated in 130 HA and 134 KA patients preoperatively and 1-year postoperatively.Results - To suit Danish patients of today, several adaptations were required. Prior to interviews, 4 patients were excluded, and 11 misinterpreted the answer options. Examiners rated the remaining 65 patients (mean age 67 years) 0.2-1.6 UCLA levels lower than patients themselves. The 130 HA and 134 KA patients (mean age 71/68 years) changed from 4.3 (SD 1.9)/4.5 (1.8) preoperatively to 6.6 (1.8)/6.2 (1.0) at 1-year follow-up. 103 (79%) HA and 89 (66%) KA patients reported increased activity. Effect sizes were large (1.2/0.96). Knee patients reaching minimal important change (MIC, ≥ 8 Oxford Knee Score points) had higher 1-year UCLA scores than patients not reaching MIC.Interpretation - Original scale development was undocumented. Content validity was questionable, and there was discrepancy between patient and examiner estimates. UCLA appears valuable for measuring change in self-reported physical activity on a group level. 4 out of 5 HA patients and 2 out of 3 KA patients were more physically active 1 year after joint replacement surgery.

Does intraoperative contamination during primary knee arthroplasty affect patient-reported outcomes for patients who are uninfected 1 year after surgery? A prospective cohort study of 714 patients.

Background and purpose - It is well recognized that some knee arthroplasty (KA) patients present with prolonged postoperative inflammation and some develop persistent pain. It can reasonably be speculated that some of these problems develop because of low-grade infections with low virulence bacteria caused by intraoperative contamination. This prospective study was performed to investigate whether intraoperative contamination results in lower patient-reported outcomes (PRO) for patients who were clinically uninfected in the first year after surgery. Patients and methods - We combined data from 2 major prospective studies on patients undergoing primary KA at 2 Danish hospitals between September 2016 and January 2018. Pre- and postoperative (1.5, 3, 6, and 12 months) PROs and intraoperative microbiological cultures were obtained on a total of 714 patients who were included in the study. Based on the microbiological cultures, the patients were divided into 2 groups, contaminated and non-contaminated, and differences in PROs between the 2 groups were analyzed. Results - 84 of 714 (12%) patients were intraoperatively contaminated; none of the 714 patients developed clinical infection. The preoperative Oxford Knee Score was 24 and 23 for contaminated and non-contaminated patients, respectively, improving to 40 and 39 at 1 year (p = 0.8). 1-year AUC for Oxford Knee Score and absolute improvement at each postoperative time point for Forgotten Joint Score and EQ-5D-5L also were similar between contaminated and non-contaminated patients. Interpretation - Patient-reported outcomes from 714 patients do not indicate that intraoperative contamination affects the knee-specific or general health-related quality of life in primary KA patients who are clinically uninfected 1 year after surgery.

Knee Osteoarthritis Patients Can Provide Useful Estimates of Passive Knee Range of Motion: Development and Validation of the Copenhagen Knee ROM Scale.

BACKGROUND: Knee arthroplasty does not always require extensive long-term follow-up. If knee range of motion (ROM) could be assessed reliably by patients, some follow-up visits might be replaced by patient-reported outcome measures, and this additional information could be reported directly to registers. We developed and tested the validity and reliability of a simple scale for patients to self-report their passive knee ROM. METHODS: Through an iterative process, we created a 2-item scale with 11 illustrations of knee motion in 15° increments. The validity and reliability was tested in knee osteoarthritis and arthroplasty patients at different treatment stages, many with poor ROM. Patient estimates were compared to passive goniometer measurements performed blindly by a physiotherapist and a junior orthopedic surgeon. RESULTS: The mean difference between 100 patients' (70.9 years) estimates and goniometer measurements was -0.7° (standard deviation, 12.3°) for flexion and 1.1° (standard deviation, 11.6°) for extension, both not significant. Correlation was 0.79 and 0.63, and kappa values at retest were 0.84 and 0.66. For flexion < 110°, sensitivity of patient estimates was 88% and specificity was 88%. For a limit of 100°, values were 95% and 81%. For extension deficits >10°, sensitivity was 78% and specificity 70%. Values were 100% and 66% for a 15° limit. CONCLUSION: The Copenhagen Knee ROM Scale is a patient-friendly and feasible alternative to passive ROM measurement for registers, research, and selected clinical use. This scale appears reliable and valid compared to reports of similar tools, and patient estimates are better correlated to goniometer measurements.

Clinicians' heuristic assessments of radiographs compared with Kellgren-Lawrence and Ahlbäck ordinal grading: an exploratory study of knee radiographs using paired comparisons.

OBJECTIVES: Ordinal scales provide means for communicating the severity of a condition, but they are affected by cognitive biases, they introduce statistical problems and they sacrifice resolution. Clinicians discern more details than contained in scales, for example, when assessing radiographs, but clinicians' distinctions are often based on experience-based rules of thumb, that is, heuristics. The objectives of this study are to compare clinicians' heuristic assessments to ordinal grading, to identify case elements that influence clinicians' judgements and to present a method for quantifying heuristic assessments. DESIGN: Clinicians were presented with 17 207 random pairs from a set of 1087 knee radiographs. For each pair, the radiograph with more severe osteoarthritis was selected. The Bradley-Terry model was used to calculate an osteoarthritis strength parameter for each radiograph. Similarly, strength parameters were determined for 12 morphological features with five additional features being considered either present or absent. All radiographs were also graded according to conventional ordinal systems (Kellgren-Lawrence and Ahlbäck). Relations between clinicians' judgements and (1) the heuristics-based osteoarthritis strength, (2) conventional ordinal systems and (3) morphological features were investigated. RESULTS: Receiver operating characteristic analysis showed that the Bradley-Terry model provided a good description of clinicians' assessments (area under the curve (AUC)=0.97, 95% CI 0.968 to 0.972). Morphological features (AUC=0.90, 95% CI 0.900 to 0.908) provided a superior description of clinicians' choices compared with conventional ordinal systems (AUC=0.88, 95% CI 0.878 to 0.887 and AUC=0.80, 95% CI 0.796 to 0.809) for Ahlbäck and Kellgren-Lawrence, respectively). The features most strongly associated with osteoarthritis strength were medial joint space width, flattening of the medial femoral and tibial condyles, medial osteophytes and alignment. CONCLUSIONS: Heuristics-based assessments give a better distinction than conventional grading systems of knee osteoarthritis. The example presents a general approach to evaluate which features are part of experts' heuristics. The data suggest that experts discern more details than included in conventional ordinal grading systems. Quantitative heuristic assessments may replace ordinal scales.

[Volar dislocation of the second and third carpometacarpal joint three months after a fall during a soccer game]. / Volar luksation af anden og tredje metacarp erkendt tre måneder efter fald under fodboldspil.

Volar dislocation of the second and third carpometacarpal joint is extremely rare and most often caused by high-energy trauma. In this case a 15-year-old boy fell on his hand while playing soccer. The injury was undiagnosed for three months, perhaps due to an ipsilateral forearm fracture. He was treated with open reduction and Kirchner wire fixation for nine weeks. At two years follow-up he had a painfree hand with a 20% reduction in grip strength.