Radiostereometic analysis (RSA) is a precise method for the functional assessment of joint kinematics. Traditionally, the method is based on tracking of surgically implanted bone markers and analysis is user intensive. We propose an automated method of analysis based on models generated from computed tomography (CT) scans and digitally reconstructed radiographs. The study investigates method agreement between marker‐based RSA and the CT bone model‐based RSA method for assessment of knee joint kinematics in an experimental setup. Eight cadaveric specimens were prepared with bone markers and bone volume models were generated from CT‐scans. Using a mobile fixture setup, dynamic RSA recordings were obtained during a knee flexion exercise in two unique radiographic setups, uniplanar and biplanar. The method agreement between marker‐based and CT bone model‐based RSA methods was compared using bias and LoA. Results obtained from uniplanar and biplanar recordings were compared and the influence of radiographic setup was considered for clinical relevance. The automated method had a bias of −0.19 mm and 0.11° and LoA within ±0.42 mm and ±0.33° for knee joint translations and rotations, respectively. The model pose estimation of the tibial bone was more precise than the femoral bone. The radiographic setup had no clinically relevant effect on results. In conclusion, the automated CT bone model‐based RSA method had a clinical precision comparable to that of marker‐based RSA. The automated method is non‐invasive, fast, and clinically applicable for functional assessment of knee kinematics and pathomechanics in patients.

BackgroundSupplemental oxygen is recommended during the initial treatment of trauma patients according to several guidelines, but the supporting evidence is sparse. We aimed to describe the use of supplemental oxygen and occurrence of hyperoxemia in the initial phase of trauma management at two level 1 trauma centers, TC1 and TC2.MethodsIn this prospective, observational study we included trauma patients ≥16 years of age. Data on pre‐ and in‐hospital supplemental oxygen, arterial oxygen tension (PaO2), and outcomes (in‐hospital mortality, hospital‐ and intensive care unit length of stay) were collected.ResultsWe included 56 patients. There were 22 (39%) females with a mean age of 49 years (SD: 18) and a median Injury Severity Score of 9 (IQR: 4‐14, n = 49). A total of 23 (45%) out of 51 spontaneously breathing patients received pre‐hospital supplemental oxygen, but did not differ significantly from the patients that did not receive supplemental oxygen. In‐hospital, 29 (59%) out of 49 spontaneously breathing patients received supplemental oxygen. The median PaO2 was 26.5 kPa [IQR: 22.2‐34.1] in four intubated patients and 12.3 kPa [IQR: 9.7‐25.7] in eight patients with spontaneous respiration on supplemental oxygen. At TC1 a significantly greater proportion of spontaneously breathing patients received both pre‐hospital (TC1: 18 [64%]; TC2: 5 [21%], P = 0.002) and in‐hospital (TC1: 24 [92%]; TC2: 7 [30%], P < 0.001) supplemental oxygen.ConclusionApproximately 50% of trauma patients received supplemental oxygen during the initial treatment. Hyperoxemia was a common finding for patients treated with supplemental oxygen, and it was more pronounced in intubated patients.

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