Impact of surgical procedures on soft tissue microcirculation in calcaneal fractures: A prospective longitudinal cohort study.

PURPOSE: Wound healing complications are a major concern after open reduction and internal fixation (ORIF) in patients with calcaneal fractures. Microcirculation is known to play a key role in bone and soft tissue healing. The present study aimed to characterize and contrast the dynamics of changes in microcirculation comparing two different surgical procedures: A) ORIF and B) a minimally invasive approach (MIA). METHODS: Blood flow (BF[AU]), oxygen saturation (sO2[%]) and relative amount of haemoglobin (rHb[AU]) were measured at two depths (2 mm and 8 mm) non-invasively by spectrophotometry (Micro-Lightguide O2C®, LEA Medizintechnik, Giessen, Germany) before surgery and every 24 h after surgery for a duration of six days. A linear mixed model (LMM) was used to analyse longitudinal data and repeated measurements. RESULTS: Nineteen patients (44 years, range 21.9-71.0 years) were enrolled in the study. Surgical treatment consisted of ORIF (n = =15) and MIA (n = =9). The postoperative BF and sO2 at the 2 mm and 8 mm depths were higher in the ORIF group (BF: p < 0.001, p = =0.003; sO2: p = =0.001, p = =0.011). The BF at the 2 mm and 8 mm depths increased after surgery (2 mm: p = =0.003, 8 mm: p = =0.001) in both groups. This increase did not correlate with the surgical technique. sO2 and rHb values at the 8 mm depth decreased after surgery (sO2: p = =0.008, rHb: p < 0.001) in both groups, whereas sO2 at the 2 mm depth increased after surgery (p = =0.003). Furthermore, the surgical technique correlated with the postsurgical course of sO2 values at the 2 mm depth (p = =0.042). CONCLUSIONS: The spectrophotometry results were in line with the generally accepted phases of soft tissue wound healing. Postsurgical changes in microcirculation are predominantly independent of surgical techniques and may be primarily determined by wound and fracture healing. Future studies should focus on the potential of spectrophotometry to monitor wound healing after surgery. Moreover, studies with longer observation periods are needed in order to examine the changes in microcirculation during all wound-healing phases.

Arthroscopy or ultrasound in undergraduate anatomy education: a randomized cross-over controlled trial.

BACKGROUND: The exponential growth of image-based diagnostic and minimally invasive interventions requires a detailed three-dimensional anatomical knowledge and increases the demand towards the undergraduate anatomical curriculum. This randomized controlled trial investigates whether musculoskeletal ultrasound (MSUS) or arthroscopic methods can increase the anatomical knowledge uptake. METHODS: Second-year medical students were randomly allocated to three groups. In addition to the compulsory dissection course, the ultrasound group (MSUS) was taught by eight, didactically and professionally trained, experienced student-teachers and the arthroscopy group (ASK) was taught by eight experienced physicians. The control group (CON) acquired the anatomical knowledge only via the dissection course. Exposure (MSUS and ASK) took place in two separate lessons (75 minutes each, shoulder and knee joint) and introduced standard scan planes using a 10-MHz ultrasound system as well as arthroscopy tutorials at a simulator combined with video tutorials. The theoretical anatomic learning outcomes were tested using a multiple-choice questionnaire (MCQ), and after cross-over an objective structured clinical examination (OSCE). Differences in student's perceptions were evaluated using Likert scale-based items. RESULTS: The ASK-group (n = 70, age 23.4 (20-36) yrs.) performed moderately better in the anatomical MC exam in comparison to the MSUS-group (n = 84, age 24.2 (20-53) yrs.) and the CON-group (n = 88, 22.8 (20-33) yrs.; p = 0.019). After an additional arthroscopy teaching 1% of students failed the MC exam, in contrast to 10% in the MSUS- or CON-group, respectively. The benefit of the ASK module was limited to the shoulder area (p < 0.001). The final examination (OSCE) showed no significant differences between any of the groups with good overall performances. In the evaluation, the students certified the arthroscopic tutorial a greater advantage concerning anatomical skills with higher spatial imagination in comparison to the ultrasound tutorial (p = 0.002; p < 0.001). CONCLUSIONS: The additional implementation of arthroscopy tutorials to the dissection course during the undergraduate anatomy training is profitable and attractive to students with respect to complex joint anatomy. Simultaneous teaching of basic-skills in musculoskeletal ultrasound should be performed by medical experts, but seems to be inferior to the arthroscopic 2D-3D-transformation, and is regarded by students as more difficult to learn. Although arthroscopy and ultrasound teaching do not have a major effect on learning joint anatomy, they have the potency to raise the interest in surgery.