Aktuelle Aspekte der Diagnostik und Therapie von Instabilitäten des Schultereckgelenks

Instabilitäten des Schultereck- bzw. Acromioclavicular(AC)gelenks sind häufige Verletzungen des Schultergürtels, die in der Regel durch einen Sturz auf die Schulter verursacht werden und vor allem junge und sportlich aktive Menschen betreffen. Für die Wahl der geeigneten Therapie ist neben Alter und Funktionsanspruch des Patienten vor allem der Grad der Instabilität des Schultereckgelenks ausschlaggebend. Diese wird nach Rockwood anhand des Ausmaßes der vertikalen Instabilität bzw. Translation klassifiziert. Die dynamisch posteriore Translation (DPT) hingegen wird nicht bzw. nur als statisch posteriore Dislokation beim Rockwood Typ IV berücksichtigt. Klinische Studien konnten jedoch zeigen, dass die DPT ein entscheidender Einflussfaktor auf das klinische Outcome bei Instabilitäten des Schultereckgelenks ist. Ziel der vorliegenden Untersuchungen war es, die DPT in modifizierten bilateralen Röntgenaufnahmen nach Alexander zu quantifizieren und mit klinischen und radiologischen Parametern zu korrelieren (Publikation 1), die klinischen und radiologischen Ergebnisse der arthroskopischen Stabilisierung der akuten AC-Gelenkssprengung unter zusätzlicher Verwendung einer acromioclaviculären Cerclage zur Adressierung der DPT zu evaluieren (Publikation 2) und die klinischen und radiologischen Ergebnisse der arthroskopischen Stabilisierung von chronischen Instabilitäten des AC-Gelenks unter Berücksichtigung der vorausgegangenen Therapie zu beurteilen (Publikation 3). Mit der Bestimmung der Überlappungslänge des AC-Gelenks (OLAC) konnte eine Messmethode zur Quantifizierung der DPT in den Alexander-Aufnahmen entwickelt werden, die sowohl mit klinischen als auch radiologischen Parametern korreliert und somit die Bedeutung der horizontalen Translation bei Instabilitäten des AC-Gelenks unterstreicht. Bei der Stabilisierung von akuten AC-Gelenkssprengungen konnte gezeigt werden, dass die coracoclaviculäre Doppel-Button-Technik mit zusätzlicher Verwendung einer acromioclaviculären Cerclage gute klinische Ergebnisse erzielt und die DPT im Vergleich zur bisher angewandten Technik reduziert werden kann. Die operative Rekonstruktion von chronischen Instabilitäten des AC-Gelenks unter Verwendung einer autologen Gracilissehne und synthetischer coracoclaviculärer Augmentation führte sowohl als Revisionseingriff nach gescheiterter initialer AC-Gelenksstabilisierung als auch bei nicht voroperierten Patienten mit chronischer Schultereckgelenkinstabilität zu zufriedenstellenden klinischen und radiologischen Ergebnissen. Zusammengefasst befasst sich die Dissertationsschrift mit aktuellen Aspekten der Diagnostik und Therapie von Instabilitäten des Schultereckgelenks unter besonderer Berücksichtigung der dynamisch horizontalen Translation, welche bisher in der Rockwood Klassifikation nur unzureichend abgebildet ist.Instabilities of the acromioclavicular (AC) joint represent one of the most common injuries of the shoulder girdle, are usually caused by a direct fall on the shoulder and are mainly affecting young patients, who are active in sports. The treatment decision process is influenced by age and functional demands of the patient but mostly by the grade of instability of the AC-joint. AC-joint separations are commonly categorised according to the Rockwood classification system, which is based on the severity of vertical instability. The horizontal component of instability with the dynamic posterior translation (DPT) is neglected in this classification system and only represented in the Rockwood type IV as a static posterior dislocation. However, clinical studies showed that DPT is a crucial factor influencing instabilities of the AC-joint. Aim of the publications included in this thesis was to quantify DPT in modified Alexander views and test for correlation with clinical and radiological parameter (publication 1), to evaluate the clinical and radiological results of the arthroscopic stabilization of acute AC-joint separations using an additional acromioclavicular cerclage addressing the DPT (publication 2) and to evaluate the clinical and radiological outcome of the arthroscopic stabilization of chronic AC-joint instability with respect to the prior treatment (publication 3). With the measurement of the overlapping length of the AC-joint (OLAC) we found a convenient method for quantification of DPT in modified Alexander-views, which correlates with clinical and radiological parameters underlining the importance of horizontal translation in patients with AC-joint instability. The coracoclavicular double-button technique with an additional acromioclavicular cerclage for acute AC-joint separation leads to good clinical results and reduces DPT compared to techniques which were used before. The operative reconstruction of chronic instabilities of the AC-joint using a gracilis tendon autograft with synthetic coracoclavicular augmentation leads to satisfying clinical and radiological results in primary or revision surgical procedures after failed initial AC-joint stabilization. In conclusion, this thesis deals with current aspects of the diagnostic and treatment of instabilities of the AC-joint with emphasis on the DPT, which is up until now insufficiently respected in the Rockwood classification system

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

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

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

Inter-Observer and Intra-Observer Reliability Assessment of the Established Classification Systems for Periprosthetic Shoulder Fractures

This study evaluated the reliability and comprehensiveness of the Unified classification system (UCPF), Wright & Cofield, Worland and Kirchhoff classifications and related treatment recommendations for periprosthetic shoulder fractures (PPSFx). Two shoulder arthroplasty specialists (experts) and two orthopaedic residents (non-experts) assessed 20 humeral-sided and five scapula-sided cases of PPSFx. We used the unweighted Cohen's Kappa (?) for measuring the intra-observer reliability and Krippendorff's alpha (a) for measuring the inter-observer reliability. The inter-rater reliabilities for the Wright & Cofield and Worland classifications were substantial for all groups. The expert and non-expert groups for UCPF also showed substantial inter-rater agreement. The all-rater group for the UCPF and the expert and non-expert group for the Kirchhoff classification revealed moderate inter-rater reliability. For the Kirchhoff classification, only fair inter-rater reliability was found for the non-expert group. Almost perfect intra-rater reliability was measured for all groups of the Wright & Cofield classification and the all-rater and expert groups of the UCPF. All groups of the Kirchhoff and Worland classifications and the group of non-experts for the UCPF had substantial intra-rater reliabilities. Regarding treatment recommendations, substantial inter-rater and moderate intra-rater reliabilities were found. Simple classification systems for PPSFx (Wright & Cofield, Worland) show the highest inter- and intra-observer reliability but lack comprehensiveness as they fail to describe scapula-sided fractures. The complex Kirchhoff classification shows limited reliability. The UCPF seems to offer an acceptable combination of comprehensiveness and reliability

Conservative treatment of acute traumatic posterior shoulder dislocations (Type A) is a viable option especially in patients with centred joint, low gamma angle, and middle or old age

Purpose: Purpose of this study was to evaluate the mid- to long-term outcome after conservatively treated first-time posterior shoulder dislocations and to determine structural defects associated with failure. Methods: In this multi-centric retrospective study, 29 shoulders in 28 patients with first-time acute posterior shoulder dislocation (Type A1 or A2 according to the ABC classification) and available cross-sectional imaging were included. Outcome scores as well as radiological and magnetic resonance imaging were obtained at a mean follow-up of 8.3 +/- 2.7 years (minimum: 5 years). The association of structural defects with redislocation, need for secondary surgery, and inferior clinical outcomes were analysed. Results: Redislocation occurred in six (21%) shoulders and nine shoulders (31%) underwent secondary surgery due to persistent symptoms. The posttraumatic posterior glenohumeral subluxation was higher in the redislocation group compared to the no redislocation group; however, statistical significance was not reached (61.9 +/- 12.5% vs. 50.6 +/- 6.4%). Furthermore, a higher adapted gamma angle was observed in the failed conservative treatment group versus the conservative treatment group, similarly without statistically significant difference (97.8 degrees +/- 7.2 degrees, vs. 93.3 degrees +/- 9.7 degrees). The adapted gamma angle was higher than 90 degrees in all patients of failed conservative therapy and the redislocation group. An older age at the time of dislocation showed a significant correlation with better clinical outcomes (SSV: r = 0.543, p = 0.02; ROWE: r = 0.418, p = 0.035 and WOSI: r = 0.478, p = 0.045). Posterior glenohumeral subluxation after trauma correlated with a worse WOSI (r = - 0.59, p = 0.02) and follow-up posterior glenohumeral decentring (r = 0.68, p = 0.007). The gamma angle (r = 0.396, p = 0.039) and depth of the reverse Hill-Sachs lesion (r = 0.437, p = 0.023) correlated significantly with the grade of osteoarthritis at follow-up. Conclusion: Conservative treatment is a viable option in patients with an acute traumatic posterior shoulder dislocation with good outcome after mid- and long-term follow-up especially in patients with centred joint, low gamma angle, and middle or old age

Arthroscopically assisted stabilization of chronic bidirectional acromioclavicular joint instability using a low-profile implant and a free tendon graft

&lt;jats:title&gt;Abstract&lt;/jats:title&gt;&lt;jats:sec&gt; &lt;jats:title&gt;Background&lt;/jats:title&gt; &lt;jats:p&gt;Economic burden and personnel shortages lead to a reduction in the time spent on surgical training of young resident physicians. This underlines the importance of courses for learning and optimizing surgical skills. Particularly for orthopaedic trauma surgery, training on fractured cadaveric specimens has proven highly useful. The present study investigates a method to induce realistic fracture patterns in fresh frozen elbow specimens, leaving the skin and soft tissue envelope intact.&lt;/jats:p&gt; &lt;/jats:sec&gt;&lt;jats:sec&gt; &lt;jats:title&gt;Methods&lt;/jats:title&gt; &lt;jats:p&gt;For fracture simulation, 10 human cadaveric specimens with intact soft tissue envelopes were placed in 90° flexion in a custom-made high-impact test bench and compressed by an impactor. The fractures were subsequently classified using conventional x‑rays.&lt;/jats:p&gt; &lt;/jats:sec&gt;&lt;jats:sec&gt; &lt;jats:title&gt;Results&lt;/jats:title&gt; &lt;jats:p&gt;Of the 10 specimens, 6 could be classified as distal humerus fractures and 4 as olecranon fractures. The fractures of the distal humerus were mainly type C according to &lt;jats:italic&gt;Arbeitsgemeinschaft Osteosynthesefragen&lt;/jats:italic&gt; (AO) criteria, the olecranon fractures were mainly type IIB according to the Mayo classification. Subsequently, all 10 specimens would have been appropriate for use in musculoskeletal trauma courses.&lt;/jats:p&gt; &lt;/jats:sec&gt;&lt;jats:sec&gt; &lt;jats:title&gt;Conclusion&lt;/jats:title&gt; &lt;jats:p&gt;With the given setup it was possible to induce realistic fracture patterns in fresh frozen cadaveric specimens. The advantage of the presented technique lies in the preservation of soft tissue. With their intact soft tissue envelopes, these pre-fractured preparations could be used in courses to precisely train resident physicians directly on human cadaver preparations. Further research should focus on finding reliable predictors to improve the precision of fracture induction in specimens.&lt;/jats:p&gt; &lt;/jats:sec&gt