Certifying experimental errors in quantum experiments

When experimental errors are ignored in an experiment, the subsequent analysis of its results becomes questionable. We develop tests to detect systematic errors in quantum experiments where only a finite amount of data is recorded and apply these tests to tomographic data taken in an ion trap experiment. We put particular emphasis on quantum state tomography and present three detection methods: the first two employ linear inequalities while the third is based on the generalized likelihood ratio.Comment: 4+ pages, 2 figures, 1 table, published versio

Effect of glenoid concavity loss on shoulder stability- a case report in a professional wrestler

Background Current glenoid defect measurement techniques only quantify bone loss in terms of defect diameter or surface. However, the glenoid depth plays an important role in shoulder stabilization by means of concavity compression. Case presentation We present a case of a professional wrestler who suffered from anterior shoulder instability after sustaining a bony Bankart lesion without loss of glenoid surface area but flattening of the concavity due to medialization of the fragment. The patient’s glenoid concavity was reconstructed arthroscopically by reduction and percutaneous screw fixation of the bony fragment along with a capsulo-ligamentous shift. Changes of the glenoid concavity with according alterations in the Bony Shoulder Stability Ratio (BSSR) were analyzed on pre-op, post-op, and follow-up CT scans. Postoperative CT scans revealed a deepened concavity (3.3 mm) and improved BSSR (46.1 %) compared to pre-op scans (0.7 mm; 11.3 %). Follow-up CT scans showed a slight remodeling of the glenoid concavity (3.2 mm) with steady BSSR (44.7 %). Conclusion This case shows that the passive stabilizing effect of the glenoid can be compromised by loss of concavity despite the absence of loss of articular surface. Therefore, addressing the concavity loss and resulting reduction of the BSSR is recommended in these cases. Bony Bankart repair was successful in restoring the BSSR of the patients shoulder as determined by mathematical calculations based on CT scans

Arthroscopic iliac crest bone grafting in recurrent anterior shoulder instability: minimum 5-year clinical and radiologic follow-up

Purpose: To investigate the clinical and radiologic mid- to long-term results of arthroscopic iliac crest bone-grafting for anatomic glenoid reconstruction in patients with recurrent anterior shoulder instability. Methods: Seventeen patients were evaluated after a minimum follow-up of 5 years. Clinical [range of motion, subscapularis tests, apprehension sign, Subjective Shoulder Value (SSV), Constant Score (CS), Rowe Score (RS), Walch Duplay Score (WD), Western Ontario Shoulder Instability Index (WOSI)], and radiologic [X-ray (true a.p., Bernageau and axillary views) and computed tomography (CT)] outcome parameters were assessed. Results: Fourteen patients [mean age 31.1 (range 18–50) years] were available after a follow-up period of 78.7 (range 60–110) months. The SSV averaged 87 (range 65–100) %, CS 94 (range 83–100) points, RS 89 (range 30–100) points, WD 87 (range 25–100) points, and WOSI 70 (range 47–87) %. The apprehension sign was positive in two patients (14%). One patient required an arthroscopic capsular plication due to a persisting feeling of instability, while the second patient experienced recurrent dislocations after a trauma, but refused revision surgery. CT imaging showed a signifcant increase of the glenoid index from preoperative 0.8±0.04 (range 0.7–0.8) to 1.0±0.11 (range 0.8–1.2) at the fnal follow-up (p<0.01). Conclusion: Arthroscopic reconstruction of anteroinferior glenoid defects using an autologous iliac crest bone-grafting tech nique yields satisfying clinical and radiologic results after a mid- to long-term follow-up period. Postoperative re-dislocation was experienced in one (7.1%) of the patients due to a trauma and an anatomic reconstruction of the pear-shaped glenoid confguration was observed. Level of evidence IV

The inter-individual anatomical variation of the trochlear notch as a predisposition for simple elbow dislocation

Purpose: Besides the multi-layered capsule-ligamentous complex of the elbow joint the high bony congruence in the ulnohumeral joint contributes to elbow stability. Therefore, we assume that specific anatomical configurations of the trochlear notch predispose to dislocation. In case of ligamentous elbow dislocation both conservative and surgical treatment is possible without a clear treatment algorithm. Findings of constitutional bony configurations could help deciding for the best treatment option. Methods: In this retrospective matched-pair analysis we compared MRI imaging from patients sustaining a primary traumatic elbow dislocation (instability group) with patients suffering from chronic lateral epicondylitis (control group), treated between 2009 and 2019. Two independent observers measured different anatomical landmarks of the trochlear notch in a multiplanar reconstructed standardized sagittal trochlear plane (SSTP). Primarily, opening angle and relative depth of the trochlear notch were determined. After adjustment to the proximal ulnar rim in the SSTP, coronoid and olecranon angle, the articular angle as well as the ratio of the tip heights of the trochlear notch were measured. Results: We compared 34 patients in the instability group (age 48 +/- 14 years, f/m 19/15) with 34 patients in the control group (age 47 +/- 16 years, f/m 19/15). Instability group showed a significantly larger opening angle (94.1 degrees +/- 6.9 degrees vs. 88.5 degrees +/- 6.9 degrees, p = 0.0002), olecranon angle (60.9 degrees +/- 5.3 degrees vs. 56.1 degrees +/- 5.1 degrees, p < 0.0001) and articular angle (24.7 degrees +/- 6.4 degrees vs. 22.3 degrees +/- 5.8 degrees, p = 0.02) compared to the control group. Measuring the height from the coronoid (ch) and olecranon (oh) tip also revealed a significantly larger tip ratio (tr = ch/oh) in the instability group (2.7 +/- 0.8 vs. 2.2 +/- 0.5, p < 0.0001). The relative depth (61.0% +/- 8.3% vs. 62.7% +/- 6.0%, p = 0.21) of the trochlear notch as well as the coronoid angle (32.8 degrees +/- 4.5 degrees vs. 31.7 degrees +/- 5.2 degrees, p = 0.30) showed no significant difference in the instability group compared to the control group. The interrater reliability of all measurements was between 0.83 and 0.94. Conclusion: MRI of patients with elbow dislocation show that there seems to be a bony anatomical predisposition. According to the results, it seems reasonable to include predisposing bony factors in the decision-making process when surgical stabilization and conservative treatment is possible. Further biomechanical studies should prove these assumptions to generate critical bony values helping surgeons with decision making

High rate of unexpected positive cultures in presumed aseptic revision of stiff shoulders after proximal humerus osteosynthesis

Background: The aim of this study was to investigate the prevalence of positive microbiology samples after osteosynthesis of proximal humerus fractures at the time of revision surgery and evaluate clinical characteristics of patients with positive culture results. Methods: All patients, who underwent revision surgery after locked platting, medullary nailing or screw osteosynthesis of proximal humeral fractures between April 2013 and July 2018 were retrospectively evaluated. Patients with acute postoperative infections, those with apparent clinical signs of infection and those with ≤1 tissue or only sonication sample obtained at the time of implant removal were excluded. Positive culture results of revision surgery and its correlation with postoperative shoulder stiffness was analyzed in patients with an interval of ≥6 months between the index osteosynthesis and revision surgery. Results: Intraoperatively obtained cultures were positive in 31 patients (50%). Cutibacterium acnes was the most commonly isolated microorganism, observed in 21 patients (67.7%), followed by coagulase negative staphylococci in 12 patients (38.7%). There were significantly more stiff patients in the culture positive group compared to the culture-negative group (19/21, 91% vs. 15/26, 58%, p = 0.02). Furthermore, 11 of 12 (91.7%) patients with growth of the same microorganism in at least two samples had a stiff shoulder compared to 23 of 35 (65.7%) patients with only one positive culture or negative culture results (p = 0.14). Conclusion: Infection must always be considered as a possibility in the setting of revision surgery after proximal humerus osteosynthesis, especially in patients with postoperative stiffness

Long-term Outcomes of a Contemporary Arthroscopic Bankart Repair Technique in Patients With Traumatic Anterior Shoulder Instability: A Minimum 10-Year Follow-up

Background: The long-term results of arthroscopic Bankart repair are poorly reported in the literature and show recurrence rates as high as 37%. However, this high failure rate is based on historical studies of patients with critical defects stabilized using older techniques. Purpose: To evaluate the long-term clinical outcomes of arthroscopic Bankart repair using a contemporary technique with a minimum of 3 suture anchors in patients with traumatic anterior instability and to assess possible risk factors for recurrent instability. Study design: Case series; Level of evidence, 4. Methods: A total of 181 patients (182 shoulders), who underwent arthroscopic Bankart repair because of traumatic anterior instability between 2005 and 2014, were included in this study and evaluated at a minimum follow-up of 10 years. Exclusion criteria were previous shoulder surgery, additional stabilization procedures, use of 20%, off-track Hill-Sachs lesion). The primary outcome was recurrent instability. Secondary outcomes were the Subjective Shoulder Value (SSV), visual analog scale (VAS), Constant score, Western Ontario Shoulder Instability Index (WOSI), and Rowe score as well as sports activity level and return to sports. Risk factors for recurrent instability were analyzed. Results: The overall recurrence rate was 20.9% at a mean follow-up of 13.8 +/- 2.8 years. Age 1 dislocation before surgery. While younger age and a higher number of preoperative dislocations were potential risk factors for recurrence, a shorter interval between the first dislocation and surgery was associated with improved clinical outcomes. Therefore, patients with a high risk of redislocations should be considered for early soft tissue stabilization, while additional procedures such as remplissage should be performed for those with nonmodifiable high-risk factors

The role of serum D-Dimer for the diagnosis of periprosthetic shoulder infection

Introduction D-Dimer was recently identified as an additional biomarker in the diagnosis of hip and knee periprosthetic joint infection (PJI). Currently, there is only one study in literature dealing with the role of D-Dimer in the diagnosis of shoulder PJI. The purpose of this study was, therefore, to validate the sensitivity and specificity of D-Dimer in detecting shoulder PJI. Materials and methods All patients, who underwent septic or aseptic revision shoulder arthroplasty in our institution between November 2018 und March 2021, were analyzed. Our cohort consisted of 30 patients, of that 14 (47%) had a shoulder PJI according the last proposed criteria of the International Consensus Meeting. The diagnostic validity of serum D-Dimer regarding the detection of PJI was analyzed. Results The mean D-Dimer level was significantly higher for the patients with shoulder PJI compared to patients with aseptic failure (1.44 +/- 1 mg/l vs. 0.76 +/- 0.6 mg/l, p = 0.025). Coagulase-negative staphylococci were the most commonly isolated pathogens, in 9/14 patients (64%), followed by Cutibacterium acnes in 5/14 patients (36%). According to the ROC analysis, a serum D-Dimer threshold of 0.75 mg/l had a sensitivity of 86% and a specificity of 56% for detection of a shoulder PJI. The area under curve was 0.74. A serum C-reactive protein (CRP) cutoff of 10 mg/l showed a sensitivity of 69% and a specificity of 88%. When both serum D-Dimer and CRP above the thresholds of 0.75 mg/l and 10 mg/l, respectively, were used to identify a PJI the sensitivity and specificity were 57% and 100%, respectively. Conclusions Serum D-Dimer showed a good sensitivity but a poor specificity for the diagnosis of shoulder PJI. Combination D-Dimer and CRP led to improvement of the specificity, however, at the cost of sensitivity. Thus, combination of both methods may be used as a confirmatory test in the diagnosis of shoulder PJI but not to rule out infection

The role of serum C-reactive protein in the diagnosis of periprosthetic shoulder infection

Introduction: There is a paucity of literature regarding serum C-reactive protein (CRP) in the evaluation of a shoulder periprosthetic joint infection (PJI). The purpose of the current study was to establish cutoff values for diagnosing shoulder PJI and evaluate the influence of the type of infecting microorganism and the classification subgroups according to last proposed International Consensus Meeting (ICM) criteria on the CRP level. Materials and methods: A retrospective analysis of all 136 patients, who underwent septic or aseptic revision shoulder arthroplasty in our institution between January 2010 and December 2019, was performed. Shoulder PJI was defined according to the last proposed definition criteria of the ICM. Serum CRP levels were compared between infected and non-infected cases, between infection subgroups, as well as between different species of infecting microorganisms. A receiver-operating characteristic (ROC) analysis was performed to display sensitivity and specificity of serum CRP level for shoulder PJI. Results: A total of 52 patients (38%) were classified as infected, 18 meeting the criteria for definitive infection, 26 for probable infection and 8 for possible infection. According to the ROC curve, an optimized serum CRP threshold of 7.2 mg/l had a sensitivity of 69% and specificity of 74% (area under curve = 0.72). Patients with definitive infection group demonstrated significantly higher median serum CRP levels (24.3 mg/l), when compared to probable, possible infection groups and PJI unlikely group (8 mg/l, 8.3 mg/l, 3.6 mg/l, respectively, p < 0.05). The most common isolated microorganism was Cutibacterium acnes in 25 patients (48%) followed by coagulase-negative staphylococci (CNS) in 20 patients (39%). Patients with a PJI caused by high-virulent microorganisms had a significantly higher median serum CRP level compared to patients with PJI caused by low-virulent microorganisms (48 mg/l vs. 11.3 mg/l, p = 0.04). Conclusions: Serum CRP showed a low sensitivity and specificity for the diagnosis of shoulder PJI, even applying cutoffs optimized by receiver-operating curve analysis. Low-virulent microorganisms and patients with probable and possible infections are associated with lower CRP levels compared to patients with definitive infection and infections caused by high-virulent microorganisms

Bankart-Plus zur Behandlung von Patienten mit anteriorer Schulterinstabilität und kleinen bis moderaten Glenoiddefekten

Introduction: A large number of patients with shoulder instability also have small or moderate glenoid defects which are below the threshold size requiring bony glenoid reconstruction but are still large enough to compromise the clinical results after conventional soft-tissue stabilization. Materials and methods: In a prospective cohort study, 30 patients with anterior shoulder instability and small glenoid bone loss (max. 15% surface area) underwent the so-called Bankart plus procedure which includes capsulolabral repair using knotless anchors and interposition of a demineralized cancellous bone matrix (DCBM) between glenoid neck and labrum. Patients underwent preoperative and postoperative (6, 12, and 24 months) clinical assessment including the Western Ontario Shoulder Instability Index (WOSI), Rowe Score (RS), and Subjective Shoulder Value (SSV). Preoperative imaging included a CT scan with 3D reconstruction and measuring of the glenoid defect (Pico method). At 12 months, a follow-up MRI of the operated shoulder was performed to evaluate the integration of the labrum and graft. Results: A total of 30 patients (average age 28 years [range 18-40], n = 4 female, n = 26 male) fulfilling the inclusion and exclusion criteria were enrolled and underwent surgery with the aforementioned technique between September 2018 and October 2020. In 13 cases (43%), an additional Remplissage was conducted. Preoperative clinical assessment showed the following clinical parameter (mean value): WOSI 45 +/- 17%, RS 56 +/- 10 points, and SSV 57 +/- 19%. Preoperative CT scans showed a mean glenoid defect of 7 +/- 3%. So far 25 patients completed radiological and clinical examinations after 12 months and significant improvement has been observed compared to the preoperative values (p < 0.05). The clinical outcome parameters after 1 year are as follows (mean value): WOSI 81 +/- 15%, RS 91 +/- 8 points, and SSV 87 +/- 10%. No recurrent dislocation, no complications or adverse events have been recorded. MRI revealed good integration of the labrum and graft forming a large bump at the anterior glenoid rim. Conclusion: The Bankart plus procedure shows promising clinical and radiological results in the short-term follow-up and is a viable treatment option for patients with anterior shoulder instability and small to moderate glenoid defects

Comparison of Patients’ and Surgeons’ Expectations before Shoulder Arthroplasty

Background: Patients suffering from osteoarthritis particularly complain about pain during day and night as well as loss of function. This consequently leads to impaired quality of life and therefore psychological stress. The surgical therapy of choice is joint replacement. Regarding the outcome after operation, expectations might differ between the patient and the surgeon. This can lead to dissatisfaction on both sides. This study aimed to document patients' expectations of a planned shoulder joint replacement. The results were compared with assessments made by shoulder surgeons. Methods: In total, 50 patients scheduled for operative shoulder joint replacement were included in this study, as well as 10 shoulder surgeons. Patients were requested to fill out questionnaires preoperatively to provide sociodemographic data, PROMS (Patient-Reported Outcome Measures) with regard to the pathology and their expectations about surgery in terms of pain relief, gain of range of motion, strength as well as the impact on activities of daily and professional life and sports. In addition, surgeons were asked what they thought their patients expect. Results: The most important goal to achieve for patients was to relieve daytime pain, followed by improvement of self-care and the ability to reach above shoulder level. The most important factors for patients to achieve after operation were 'pain relief' in first place, 'movement' in second and 'strength' in third. This also applied to shoulder surgeons, who ranked 'pain relief' first, followed by 'movement' and 'strength'. When patients where asked what is most important when it comes to choosing their surgeon, 68% voted for 'surgical skills', 28% for 'age/experience', followed by 'empathy', 'sympathy' and 'appearance'. For surgeons, 'age/experience' obtained rank one, 'surgical skills' was ranked second, followed by 'sympathy', 'empathy' and 'appearance'. Surgeons significantly underrated the factor 'empathy' in favor of 'sympathy'. Conclusions: This study shows that patients' expectations for shoulder joint replacement and surgeons' assessments do not differ significantly. Relief from pain and better shoulder movement were crucial for patients to achieve after operation, which was in line with surgeons' expectations. The most important factor for choosing the surgeon was 'surgical skills' for patients, while surgeons thought they would care more about 'age and experience'. This underlines that patients' expectations should be taken into account within the preoperative medical interview. This might allow an optimization of compliance of the patients and lead to a better satisfaction on both sides