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Purpose The aim of this study was to determine the change in the long leg axis according to the preoperative knee phenotype using the mechanically aligned extension-first technique in total knee arthroplasty. The hypothesis of this study was that the knee phenotype would have an impact on the postoperative leg axis. Methods This was a retrospective comparative study comprising 224 whole-leg radiographs of 112 patients. The leg axes of the pre- and postoperative radiographs were measured and categorized into three preoperative limb phenotypes (based on the hip-knee-ankle angle [HKA]) according to Hirschmann et al. (varus—HKA 181.5°). Additionally, femoral phenotypes (based on the femoral mechanical angle [FMA], i.e., the mechanical medial distal femoral angle [mMDFA], as well as the tibial phenotypes [based on the tibial mechanical angle, i.e., the medial proximal tibial angle (MPTA)] was calculated. The change in the long leg axis was analyzed and compared with the preoperative limb phenotype. Results Significantly more patients with preoperative varus alignment shifted to neutral alignment (46.3%, n = 31) than did patients with preoperative valgus alignment (38.9%; n = 14). Moreover, 43.3% of patients (n = 29) with the varus phenotype remained in a varus alignment, compared with the 58.3% of patients with preoperative valgus phenotype (n = 21) remaining in valgus alignment. These findings were similar for both females (p p = 0.015). Conclusion Using an extension-first mechanically aligned surgical technique, varus phenotypes predominantly result in neutral leg axes or remain varus, neutral phenotypes remain neutral, and valgus phenotypes remain valgus or change to neutral phenotypes. This study showed that preoperative knee phenotypes in valgus knees influence this technique more strongly than estimated in previous investigations, which is in line with modern alignment philosophies for TKA. Level of evidence Level IV, retrospective comparative study.

PurposeThe purpose of this study was to compare the clinical and functional outcome scores following total knee arthroplasty (TKA) with two different systems. The hypothesis was that there is a difference between patients receiving the newer design than those receiving the predecessor.MethodsTwo hundred patients who underwent TKA were randomized into two groups: patients received either Attune TKA or PFC Sigma (both DePuy Synthes, Warsaw, IN). Clinically, the Knee Society Knee and Function Scores (KS and FS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Range of Motion (ROM) and Visual Analogue Scale (VAS) were evaluated and compared between the groups 2 years after surgery. 158 patients (80 in the Attune group and 78 in the PFC Sigma group) were available for follow-up.ResultsThrough bivariate analysis using parametric and non-parametric statistical tests, no significant differences in postoperative KS, FS, WOMAC, ROM or VAS between the two groups were detected. Both groups significantly improved regarding all evaluated endpoints 2 years after surgery.ConclusionsIn the current study population, no difference in clinical outcome between the two systems was found. The expected benefits of design modifications could not be observed in clinical outcome scores 2 years postoperatively. Both designs are effective options for improving pain and function in end-stage osteoarthritis.Level of evidenceI.

In combination with pain and elevated inflammatory parameters that are frequently observed following elective total hip arthroplasty (THA), air entrapment on radiographic images could be indicative of necrotising fasciitis. The aim of the present study was to analyse presence/extent of air entrapment following THA, and to correlate radiological with clinical findings. One-hundred patients undergoing short-stem elective THA (ANA NOVA Alpha Proxy-system) were prospectively included. Patients received pre- and postoperative x-rays (day 1 + discharge) of the affected hip, together with a CT-scan of the lower extremity (discharge). C-reactive-protein-(CRP), leukocyte, haemoglobin-, creatinine-, glucose-, sodium-levels – and based on these the LRINEC score– as well as pain-scores (numeral-rating-scale, NRS) at postoperative days 1, 3 and 5 were documented. Air entrapment was visible in 98% of x-rays taken postoperatively and in 93% of CT-scans at discharge. Leukocyte-levels significantly decreased from postoperative day 1 to 5. CRP-levels had a peak at the 3rd postoperative day (p LRINEC- or NRS-scores significantly correlated with presence/extent of air entrapment (p > 0.05). Considering the high rate of air entrapment following elective THA postoperatively and at discharge, suspicion of an infection with gas-producing bacteria may only be raised in case of persistent inflammatory parameters, deteriorating general condition and signs of local infection.

The development of emphysema after intramedullary nailing can represent an easily manageable complication but in the differential diagnostics it could, however, be a life-threatening infection with Clostridium perfringens. This is a report about the case of an extensive subcutaneous and retroperitoneal emphysema, which developed after intramedullary nailing of a pertrochanteric femoral fracture and where such an infection was suspected.

An observational, exploratory, cross-sectional study was performed to assess whether the presence of atypical naevi (AN) in adolescents is associated with psychological and psychovegetative stress parameters. Fifty-one students of a secondary school in Graz, Austria, completed a defined test procedure consisting of an initial period of rest, a standardised mental stress task, another period rest and a questionnaire, the change-sensitive symptom list (ASS-SYM). Electrocardiogram and blood pressure were recorded continuously. The study population was divided in two groups: probands without AN (NAN, n = 33), and probands with at least one AN (n = 18). We found higher values for the AN group in all scales of ASS-SYM, reaching statistical significance in the dimensions "nervousness and mental tension" (p = 0.025), "psychophysiological dysregulation" (p = 0.020), burden of pain" (p = 0.023) and "general symptoms and problems" (p = 0.031). Regarding physiological parameters, the AN group showed higher vegetative strain reflected in heart rate and heart rate varibility during the periods of rest as well as a reduced baroreceptor sensitivity. On the basis of our results, the presence of AN in adolescents seems to be associated with a higher vegetative arousal. Additionally, participants with AN complained significantly more often about stress-associated general psychological symptoms and problems.