Smoking undoubtedly affects human health. Investigating 2318 representative patients at a level 1 trauma center identified delayed wound healing, tissue infections, and/or sepsis as main complications in smokers following trauma and orthopedic surgery. Therefore, smoking cessation is strongly advised to improve the clinical outcome in these patients, although smoking cessation often fails despite nicotine replacement therapy raising the need for specific interventions that may reduce the complication rate. However, the underlying mechanisms are still unknown. In diabetics, delayed wound healing and infections/sepsis are associated with increased neutrophilic PADI4 expression and formation of neutrophil extracellular traps (NETs). The aim was to investigate if similar mechanisms hold for smokers. Indeed, our results show higher PADI4 expression in active and heavy smokers than non-smokers, which is associated with an increased complication rate. However, in vitro stimulation of neutrophils with cigarette smoke extract (CSE) only moderately induced NET formation despite accumulation of reactive oxygen species (ROS). Physiological levels of nicotine and its main metabolite cotinine more effectively induced NET formation, although they did not actively induce the formation of ROS, but interfered with the activity of enzymes involved in anti-oxidative defense and NET formation. In summary, we propose increased formation of NETs as possible triggers for delayed wound healing, tissue infections, and/or sepsis in smokers after a major trauma and orthopedic surgery. Smoking cessation might reduce this effect. However, our data show that smoking cessation supported by nicotine replacement therapy should be carefully considered as nicotine and its metabolite cotinine effectively induced NET formation in vitro, even without active formation of ROS.

Purpose: Identifying anatomical risk factors on recurrent dislocation after medial reefing is important for deciding surgical treatment. The present study aimed to retrospectively analyze the preoperative magnetic resonance imaging (MRI)‐based parameters of patients treated with medial reefing and whether these parameters lead to a higher risk of recurrent dislocation.Methods: Fifty‐five patients (18.6 ± 6.6 years) who underwent medial reefing after primary traumatic patellar dislocation (84% with medial patellofemoral ligament [MPFL] rupture) were included. Patients were followed up for at least 24 months postoperatively (3.8 ± 1.2 years) to assess the incidence of recurrent patellar dislocation. In patients without recurrent dislocation, the Kujala and subjective IKDC scores were assessed. Moreover, the tibial tubercle‐trochlear groove (TT‐TG), sulcus angle, patellar tilt, patellar shift, and lateral trochlea index (LTI) were measured. The patellar height was measured using the Caton‐Dechamps (CDI), Blackburne‐Peel (BPI), and Insall‐Salvati index (ISI). The cohort was subclassified into two groups with and without recurrent dislocation. Differences between groups were analyzed with respect to the MRI parameters.Results: Forty percent had a pathological sulcus angle of > 145°, 7.2% had an LTI of < 11°, 47.3% had a patellar tilt of > 20°, and 36.4% had a TT‐TG of ≥ 16 mm. Increased patellar height was observed in 34.5, 65.5, and 34.5% of the patients as per CDI, BPI, and ISI, respectively. Nineteen (34.5%) patients suffered from recurrent dislocation. Compared with patients without recurrent dislocation, those with recurrent dislocation had a significantly lower LTI (p = 0.0467). All other parameters were not significantly different between the groups. Risk factor analysis showed higher odds ratios (OR > 2), although not statistically significant, for MPFL rupture (OR 2.05 [95% confidence interval 0.38–11.03], LTI (6.6 [0.6–68.1]), TT‐TG (2.9 [0.9–9.2]), and patellar height according to ISI (2.3 [0.7–7.5]) and CDI (2.3 [0.7–7.5])). Patients without recurrent dislocation had a Kujala score of 93.7 ± 12.1 (42–100) points and an IKDC score of 90.6 ± 11.7 (55.2–100) points.Conclusion: Anatomical, MRI‐based parameters should be considered before indicating medial reefing. A ruptured MPFL, an LTI < 11°, a TT‐TG ≥ 16 mm, a patellar tilt > 20 mm, and an increased patellar height according to ISI and CDI were found to be associated, although not significantly, with a higher risk (OR > 2) of recurrent patellar dislocation after medial reefing. Thorough preoperative analysis is crucial to reduce the risk of recurrent dislocation in young patient cohorts.Level of evidence: Level IV

Purpose: Double‐level osteotomy (DLO) is a joint‐preserving technique for the treatment of symptomatic varus knee osteoarthritis (OA) in cases of femoral and tibial combined deformity. The study aimed to investigate the mid‐term survival rate (>5 years) and restoration of postoperative joint angles. Methods: Sixty‐five knees underwent DLO (medial open wedge high tibial osteotomy (MOWHT) and lateral closing wedge distal femoral osteotomy (LCWDFO) between 2011 and 2015. Minimum follow‐up was 5 years. The survival rate was recorded and, in case of conversion to knee arthroplasty, the time of conversion. Radiographs were obtained preoperatively, 6 weeks postoperatively and at the last follow‐up. On radiographs mechanical tibiofemoral angle (mTFA), mechanical medial proximal tibia angle (mMPTA), mechanical lateral distal femur angle (mLDFA), joint line convergence angle (JLCA) and joint line obliquity (JLO) were measured. The clinical outcome was measured using International Knee Documentation Committee (IKDC), Oxford and Lysholm score. Results: Forty‐nine knees (75% follow‐up) were included after 8.0 ± 1.4 years. At the last follow‐up, six knees underwent arthroplasty (7‐year survival rate: 91.8%; 5‐year survival rate: 93.9%) in average after 5.1 ± 2.3 years. Preoperatively, there was a varus deformity of −10.0 ± 2.5° (mTFA). In addition, pathologic knee joint angles with an mMPTA of 84.7 ± 2.2°, an mLDFA of 91.4 ± 2.1°, an JLCA of 3.4 ± 1.8 and a JLO of 3.0 ± 1.9°. Six weeks postoperatively mTFA was 0.7 ± 2.2° with values of mMPTA 91.0 ± 2.3°, mLDFA 86.8 ± 2.0° and JLO of 2.8 ± 2.1°. In the mid‐term, a preserved leg axis (mTFA: −0.9 ± 2.7°) and preserved joint angles (mMPTA: 90.3 ± 2.7°, mLDFA: 87.1 ± 2.3°, JLCA: 4.3 ± 1.9 JLO: 3.2 ± 2.1°) were observed. At the last follow‐up, the IKDC, Oxford Knee Score (OKS) and Lysholm score were: 61.2%, 36.1 points and 78.3 points, respectively. Conclusion: The study demonstrates that DLO is an effective surgical technique to restore physiological joint angles in patients with severe preoperative deformity and symptomatic varus OA. Mid‐term results indicate good clinical outcomes and a low conversion rate to TKA. Level of Evidence: Level IV.

Background: Reverse shoulder arthroplasty (RSA) is a frequently used therapy for complex proximal humeral fractures and posttraumatic disorders. The present study’s purpose was to assess the clinical and radiological outcome of primary and secondary RSA, and to analyze the impact of refixation of the greater tuberosity (GT). Patients and methods: 28 patients with primary fracture RSA and 18 patients with RSA due to posttraumatic disorders were examined with a mean clinical follow-up of 2.5 ± 1.73 years. Operative details and radiographs were retrospectively reviewed. Additional analyses were performed for healed and non-healed GT in primary RSA. Results: Patients with fracture RSA had higher Constant-Murley score (CMS) than secondary RSA without reaching significance (p = 0.104). No significant difference was present for the quality of life measured by the Short Form 36 (SF 36) and the range of motion. In primary RSA, 78.6% GT healed anatomically. Compared to non-healed GT, patients with healed GT had a significantly higher CMS (p = 0.011), external rotation (p = 0.026) and forward flexion (p = 0.083), whereas DASH score was lower without a significant difference (p = 0.268). SF 36 showed no significant difference. Patients with healed GT had a more neutral glenoid version (p = 0.009). Conclusion: Superior range of motion and clinical outcome scores were present for anatomically healed GT. Therefore, refixation of the tuberosities is recommended. Secondary RSA can result in inferior results compared to primary RSA, so patients need to be adequately informed.

While impaired bone remodeling contributes to osteoporosis and probably to osteoarthritis, the relations between bone turnover and key hip geometry measures such as center-edge angle (CE), neck-shaft angle (NSA) or alpha angle remain unknown. We here examined the presence of associations between two bone turnover markers with hip geometric measures in adults from the general population. Data from 2037 participants (50% women) in the Study of Health in Pomerania-TREND were examined. Hip geometric parameters were obtained using magnetic resonance imaging. Serum concentrations of carboxy-terminal telopeptide of Type I collagen (CTX, bone resorption) and intact amino-terminal propeptide of Type I procollagen (P1NP, bone formation) were measured to assess bone turnover. In sex-specific linear regression models adjusted for age, body mass index and physical inactivity, positive associations between CTX or P1NP and CE and inverse associations with NSA were detected. The latter were restricted to men. Thus, an increase in bone formation or resorption is related to less dysplastic (both sexes). Additionally, men with more valgus hips have lower bone turnover markers. For the alpha angle, no significant association was present. The observed associations between bone turnover markers and hip geometry confirm the presence of relevant relations between bone properties and hip geometry. This knowledge may aid in detection of vulnerable groups with respect to osteoarthritis and fracture risk.