Open Access

Digital nerve lesions result in a loss of tactile sensation reflected by an anesthetic area (AA) at the radial or ulnar aspect of the respective digit. Yet, available tools to monitor the recovery of tactile sense have been criticized for their lack of validity. However, the precise quantification of AA dynamics by three-dimensional (3-D) imaging could serve as an accurate surrogate to monitor recovery following digital nerve repair. For validation, AAs were marked on digits of healthy volunteers to simulate the AA of an impaired cutaneous innervation. Three dimensional models were composed from raw images that had been acquired with a 3-D camera (Vectra H2) to precisely quantify relative AA for each digit (3-D models, n= 80). Operator properties varied regarding individual experience in 3-D imaging and image processing. Additionally, the concept was applied in a clinical case study. Images taken by experienced photographers were rated better quality (p< 0.001) and needed less processing time (p= 0.020). Quantification of the relative AA was neither altered significantly by experience levels of the photographer (p= 0.425) nor the image assembler (p= 0.749). The proposed concept allows precise and reliable surface quantification of digits and can be performed consistently without relevant distortion by lack of examiner experience. Routine 3-D imaging of the AA has the great potential to provide visual evidence of various returning states of sensation and to convert sensory nerve recovery into a metric variable with high responsiveness to temporal progress.

Over the past decade, veno-venous extracorporeal membrane oxygenation (vvECMO) has been increasingly utilized in respiratory failure in patients. This study presents our institution´s experience focusing on the life span of ECMO systems reflecting the performance of a particular system. A retrospective review of our ECMO database identified 461 adult patients undergoing vvECMO (2010-2017). Patients that required more than one system and survived the first exchange >24 hours (n = 139) were included. Life span until the first exchange and exchange criteria were analyzed for all systems (PLS, Cardiohelp HLS-set, both Maquet Cardiopulmonary, Rastatt, Germany; Deltastream/Hilite7000LT, iLA-activve, Xenios/NovaLung, Heilbronn, Germany; ECC.O5, LivaNova, Mirandola, Italy). At our ECMO center, the frequency of a system exchange was 30%. The median (IQR) life span was 9 (6-12) days. There was no difference regarding the different systems (p = 0.145 and p = 0.108, respectively). However, the Deltastream systems were exchanged more frequently due to elective technical complications (e. g. worsened gas transfer, development of coagulation disorder, increased bleedings complications) compared to the other exchanged systems (p = 0.013). In summary, the used ECMO systems are safe and effective for acute respiratory failure. There is no evidence for the usage of a specific system. Only the increased predictability of an imminent exchange preferred the usage of a Deltastream system. However, the decision to use a particular system should not depend solely on the possible criteria for an exchange.

Purpose The purpose of this study was to quantify the influence of medial open wedge high tibial osteotomy on patellar kinematics using optical computer navigation, as anterior knee pain infrequently occurs postoperatively and the reason is still being unknown. Methods Ten medial open wedge high tibial osteotomies at supratuberosity level in 5 full body specimens were performed. The effect of the surgical procedure on patellar kinematics, measured at 5 and 10 degrees of leg alignment correction angle, was analyzed and compared to native patellar kinematics during passive motion-regarding patella shift, tilt, epicondylar distance and rotation. Linear mixed models were used for statistical analysis, a two-sidedpvalue of <= 0.05 was considered statistically significant. Results Tilt behavior, medial shift and epicondylar distance did not show a significant difference regarding natural patellar kinematics at both osteotomy levels. Both osteotomy correction angles showed a significant less external rotation of the patella (p < 0.001, respectively) compared to natural kinematics. Conclusions Except less external rotation of the patella, medial open wedge high tibial osteotomy does not seem to relevantly alter patellar alignment during passive motion. Future clinical studies have to prove the effect of MOWHTO on patellar kinematics measured in this experimental setup, especially regarding its influence on anterior knee pain.

Postoperative pain management options are of great importance for patients undergoing total hip arthroplasty, as joint replacement surgery is reported to be one of the most painful surgical procedures. This study demonstrates pain outcome until 4 weeks postoperatively and evaluates factors influencing pain in the postoperative course after total hip arthroplasty. A total of 103 patients were included in this prospective cohort trial and underwent total hip arthroplasty. Postoperative pain was described using a numerical rating scale (NRS); demographic data and perioperative parameters were correlated with postoperative pain. Evaluation of pain scores in the postoperative course showed a constant decrease in the first postoperative week (mean NRS 3.1 on day 1 to mean NRS 2.3 on day 8) and, then, a perpetual increase for 3 days (mean NRS 2.6 on day 9 to mean NRS 2.3 on day 12). Afterwards, a continuous pain-level decrease was stated (continuous to a mean NRS 0.9 on day 29). No correlation was found between the potential influencing factors sex, age, body mass index, duration of surgery, ASA score, and postoperative pain levels, but a high significant correlation could be stated for preoperative pain levels and postoperative pain intensity (pain while moving p < 0.02 to p < 0.05 depending on the time period "week 1 postoperatively", "week 2-4", or "week 1-4"; pain while resting p < 0.001, in all the measured time intervals, respectively). Increasing pain levels after the first week postoperatively, for 3 days, are most likely to be caused by the change to more extensive mobilization and physiotherapy in the rehabilitation unit. No significant influence or correlation on the intensity of postoperative pain could be found while evaluating potential predictors except preoperative pain levels. Pain management has to take these findings into account in the future to further increase patients' satisfaction in the postoperative course after total hip arthroplasty and to adapt pain management programs.

Introduction Total hip arthroplasty (THA) is reported to be one of the most painful surgical procedures. Perioperative management and rehabilitation patterns are of great importance for the success of the procedure. The aim of this cohort study was the evaluation of function, mobilization and pain scores during the inpatient stay (6 days postoperatively) and 4 weeks after fast-track THA. Materials and methods A total of 102 consecutive patients were included in this retrospective cohort trial after minimally invasive cementless total hip arthroplasty under spinal anesthesia in a fast-track setup. The extent of mobilization under full-weight-bearing with crutches (walking distance in meters and necessity of nurse aid) and pain values using a numerical rating scale (NRS) were measured. Function was evaluated measuring the range of motion (ROM) and the ability of sitting on a chair, walking and personal hygiene. Furthermore, circumferences of thighs were measured to evaluate the extent of postoperative swelling. The widespread Harris Hip Score (HHS) was used to compare results pre- and 4 weeks postoperatively. Results Evaluation of pain scores in the postoperative course showed a constant decrease in the first postoperative week (days 1-6 postoperatively). The pain scores before surgery were significantly higher than surgery (day 6), during mobilization (p < 0.001), at rest (p < 0.001) and at night (p < 0.001). All patients were able to mobilize on the day of surgery. In addition, there was a significant improvement in independent activities within the first 6 days postoperatively: sitting on a chair (p < 0.001), walking (p < 0.001) and personal hygiene (p < 0.001). There was no significant difference between the measured preoperative and postoperative (day 6 after surgery) thigh circumferences above the knee joint. Compared to preoperatively, there was a significant (p < 0.001) improvement of the HHS 4 weeks after surgery. In 100% of the cases, the operation was reported to be successful and all of the treated patients would choose a fast-track setup again. Conclusion Application of a fast-track scheme is effective regarding function and mobilization of patients. Low pain values and rapid improvement of walking distance confirms the success of the fast-track concept in the immediate postoperative course. Future prospective studies have to confirm the results comparing a conventional and a fast-track pathway.