Charakteristika und Klassifikation der funktionellen Schulterinstabilität (FSI)

Hintergrund: Abnormale Muskelaktivierungsmuster können zu Schulterinstabilität führen. In dieser prospektiven Kohortenstudie wurde diese Pathologie als funktionelle Schulterinstabilität (FSI) definiert. Eine detaillierte Analyse der FSI wurde durchgeführt, um spezifische Charakteristika der FSI aufzuzeigen. Methodik: Innerhalb eines Jahres (1/2017-12/2017) wurden 36 Fälle von FSI prospektiv rekrutiert. Die diagnostische Analyse umfasste eine klinische Untersuchung, einen Pathologie-spezifischen Fragebogen inklusive standardisierte klinische Scores (WOSI, Rowe, SSV), eine psychologische Evaluation, aktuelle Magnetresonanztomographie-Aufnahmen, eine Videodokumentation und eine dynamische fluoroskopische Analyse des Instabilitätsmechanismus. Basierend auf den gesammelten Daten wurden unterschiedliche Subgruppen von FSI dargestellt und verglichen. Ergebnisse: Gemäß des beobachteten Instabilitätsmechanismus wurde eine positionsabhängige FSI (78%) von einer nicht-positionsabhängigen FSI (22%) unterschieden. Eine kontrollierbare positionsabhängige FSI wurde in 6% und eine nicht-kontrollierbare positionsabhängige FSI in 72% der Fälle nachgewiesen, während eine kontrollierbare und nicht-kontrollierbare nicht-positionsabhängige FSI in 11% der Fälle beobachtet wurde. Die ermittelten Subgruppen der FSI offenbarten signifikante Unterschiede hinsichtlich der funktionellen Beeinträchtigung (Stabilität: p<0,001, Alltag: p=0,001, Sport: p<0,001) und in den erhobenen klinischen Scores (WOSI: p=0,002, Rowe-Score: p=0,001, SSV: p=0,001). 78% wurden als posterior, 17% als anterior und 6% als multidirektionale FSI identifiziert. Obwohl bei mehreren Studienteilnehmern konstitutionelle Veränderungen der Glenoidmorphologie oder eine Hyperlaxität beobachtet wurden, konnten nur in wenigen Fällen geringfügige, erworbene strukturelle Defekte festgestellt werden. Schlussfolgerung: Vier Subtypen von FSI wurden gemäß dem Instabilitätsmechanismus und der willkürlichen Kontrollierbarkeit bestimmt. Entsprechend war das Ausmaß der Funktionsbeeinträchtigung zwischen den Subgruppen unterschiedlich. Die meisten Fälle zeigten eine unidirektionale posteriore FSI.Background: Aberrant muscle action patterns can result in shoulder instability. In this prospective cohort study, this pathology is defined as functional shoulder instability (FSI). An in-depth analysis was performed to analyze the characteristics of FSI. Methods: Over the course of one year (1/2017-12/2017) 36 cases of FSI were recruited prospectively at the referral center. Diagnostic analysis involved a clinical examination, pathology-specific questionnaire including clinical scores (WOSI, Rowe, SSV) aswell as psychological assessment, recent magnetic resonance imaging (MRI), video documentation and dynamic fluoroscopic evaluation of the pathomechanism. Based on the collected data, distinctive subgroups of FSI were established and compared. Results: According to the observed pattern, positional FSI (78%) was differentiated from non-positional FSI (22%). Controllable positional FSI was detected in 6% and non-controllable positional FSI in 72% of the cases while controllable and non-controllable non-positional FSI were observed in 11% of all cases respectively. The determined subgroups of FSI revealed significant differences regarding functional impairment (stability: p<0.001, daily activities: p=0.001, sports activities: p<0.001) and in all clinical scores assessed (WOSI: p=0.002, Rowe-Score: p=0.001, SSV: p=0.001). 78% were identified with posterior, 17% with anterior, and 6% with multidirectional FSI. Although constitutional glenoid morphologic changes or hyperlaxity were observed in some participants, only few acquired minor structural defects were detected. Conclusion: Four subtypes of FSI were determined according to the instability mechanism and volitional control. Correspondingly, the extent of functional impairment differed between the subgroups. Most of the cases were observed with unidirectional posterior FSI

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

Arthroscopic Middle Trapezius Transfer for Treatment of Irreparable Superior Rotator Cuff Tendon Tears

Irreparable supraspinatus tendon tears are challenging to treat, especially in a young and high-demanding patient population. Whereas interposition tendon grafting and partial repair are limited by the quality of the remaining rotator cuff tendons and muscles, superior capsular reconstruction and subacromial spacers do not provide the active biomechanical principle of a contracting supraspinatus. The purpose of this technical note is to introduce an arthroscopic middle trapezius transfer below the acromion to replace the former supraspinatus unit. This technique might combine the benefits of both the static concepts seen with subacromial spacers or superior capsular reconstruction and dynamic concepts such as interposition grafting and partial repairs

Middle trapezius transfer for treatment of irreparable supraspinatus tendon tears- anatomical feasibility study

Purpose!#!The purpose of this study was to investigate the anatomical feasibility of a middle trapezius transfer below the acromion for treatment of irreparable supraspinatus tendon tears.!##!Methods!#!This study involved 20 human cadaveric shoulders in 10 full-body specimens. One shoulder in each specimen was dissected and assessed for muscle and tendon extent, force vectors, and distance to the neurovascular structures. The opposite shoulder was used to evaluate the surgical feasibility of the middle trapezius transfer via limited skin incisions along with an assessment of range of motion and risk of neurovascular injury following transfer.!##!Results!#!The harvested acromial insertion of the middle trapezius tendon showed an average muscle length of 11.7 ± 3.0 cm, tendon length of 2.7 ± 0.9 cm, footprint length of 4.3 ± 0.7 cm and footprint width of 1.4 ± 0.5 cm. The average angle between the non-transferred middle trapezius transfer and the supraspinatus was 33 ± 10° in the transversal plane and 34 ± 14° in the coronal plane. The mean distance from the acromion to the neurovascular bundle was 6.3 ± 1.3 cm (minimum: 4.0 cm). During surgical simulation there was sufficient excursion of the MTT without limitation of range of motion in a retracted scapular position but not in a protracted position. No injuries to the neurovascular structures were noted.!##!Conclusion!#!Transfer of the acromial portion of the middle trapezius for replacement of an irreparable supraspinatus seems to be feasible in terms of size, vector, excursion, mobility and safety. However, some concern regarding sufficiency of transfer excursion remains as scapula protraction can increase the pathway length of the transfer.!##!Level of evidence!#!Basic Science Study/Anatomical Study

Delphi-Verfahren zur konventionellen konservativen Therapie der funktionellen hinteren Schultergelenkinstabilität

Background: Posterior shoulder instability is caused by structural or functional defects. While the former are mostly treated surgically, physiotherapy is considered the treatment of choice in functional shoulder instability. However, it often has limited success unless very specific and intensive training programs are applied by trained experts. Currently, there is no consensus on the treatment of functional posterior shoulder instability. Objective: To improve treatment of this pathology, a standardized treatment recommendation is required to serve as a guideline for physiotherapy. The aim of this study was to establish expert consensus for treatment recommendations for functional posterior shoulder instability. Design: The Delphi survey technique was employed. Methods: A standardized training program for treatment of functional posterior shoulder instability was developed by a local expert committee. Two rounds of an online Delphi survey were then conducted. The panel of the Delphi survey comprised nine leading scientific experts in the field of functional shoulder instability who treat patients with shoulder-related problems conservatively and operatively. Results: The response rate was 100% and there were no dropouts. The final program consists of three groups of exercises with increasing difficulty. The exercises are mostly easy to perform and focus on the scapula-retracting muscles and the muscles responsible for external rotation of the shoulder. The treatment program should be executed under the supervision of a therapist at the beginning and later may be performed by the patients themselves. Conclusion: Consensus on a new exercise guideline dedicated to the treatment of functional posterior shoulder instability was achieved. This guideline should not only help to treat this challenging pathology but also provide a starting point for further scientific research and ongoing improvement.Hintergrund: Die hintere Schulterinstabilität kann durch strukturelle Schäden oder ein funktionelles Defizit bedingt sein. Während Erstere vorwiegend chirurgisch angegangen werden, gilt bei funktionellen Defiziten Physiotherapie als Mittel der Wahl. Jedoch hat diese oft nur begrenzten Erfolg, sofern nicht überaus spezifische und intensive Trainingspläne von gut ausgebildeten Trainern angewendet werden. Aktuell besteht kein Konsens hinsichtlich der Behandlung der funktionellen hinteren Schulterinstabilität. Ziel: Um die Behandlung dieser speziellen Erkrankung zukünftig zu verbessern, bedarf es eines standardisierten Behandlungsplans als Leitlinie für die Physiotherapie. Ziel dieser Studie war die Etablierung eines Expertenkonsenses zur Behandlungsempfehlung für die funktionelle hintere Schultergelenkinstabilität. Design: Es wurde die Delphi-Methode angewendet. Methoden: Ein standardisierter Trainingsplan für diese Indikation wurde von einem Expertenteam erarbeitet. Dieser Trainingsplan durchlief 2 Runden in einem Online-Delphi-Verfahren. Teilnehmer des Delphi-Verfahrens waren 9 führende Experten auf dem Gebiet der konservativen und operativen Therapie der funktionellen hinteren Schultergelenkinstabilität. Ergebnisse: Die Antwortrate in dem Delphi-Verfahren betrug 100 %, es gab keine Abbrecher. Der finale Trainingsplan untergliedert sich in 3 Gruppen von Übungen mit jeweils schrittweise ansteigender Komplexität. Die Übungen sind größtenteils leicht durchzuführen und richten sich auf die schulterblattretrahierende Muskulatur und die Außenrotatoren des Schultergelenks. Das Programm sollte zu Beginn noch unter therapeutischer Kontrolle durchgeführt werden, um eine exakte Durchführung zu gewährleisten. In späteren Stadien erfolgt es dann eigenständig durch die Patienten. Schlussfolgerung: Ein Konsens hinsichtlich eines neuen Trainingsplans als Richtlinie speziell für die Behandlung der hinteren funktionellen Schulterinstabilität wurde erreicht. Dieser Trainingsplan soll dabei helfen, diese anspruchsvolle Erkrankung zu behandeln und außerdem den Startpunkt für weiterführende wissenschaftliche Untersuchungen bilden

Delphi survey on conventional conservative treatment of functional posterior shoulder instability

&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;Posterior shoulder instability is caused by structural or functional defects. While the former are mostly treated surgically, physiotherapy is considered the treatment of choice in functional shoulder instability. However, it often has limited success unless very specific and intensive training programs are applied by trained experts. Currently, there is no consensus on the treatment of functional posterior shoulder instability.&lt;/jats:p&gt;&lt;/jats:sec&gt;&lt;jats:sec&gt;&lt;jats:title&gt;Objective&lt;/jats:title&gt;&lt;jats:p&gt;To improve treatment of this pathology, a standardized treatment recommendation is required to serve as a guideline for physiotherapy. The aim of this study was to establish expert consensus for treatment recommendations for functional posterior shoulder instability.&lt;/jats:p&gt;&lt;/jats:sec&gt;&lt;jats:sec&gt;&lt;jats:title&gt;Design&lt;/jats:title&gt;&lt;jats:p&gt;The Delphi survey technique was employed.&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;A standardized training program for treatment of functional posterior shoulder instability was developed by a local expert committee. Two rounds of an online Delphi survey were then conducted. The panel of the Delphi survey comprised nine leading scientific experts in the field of functional shoulder instability who treat patients with shoulder-related problems conservatively and operatively.&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;The response rate was 100% and there were no dropouts. The final program consists of three groups of exercises with increasing difficulty. The exercises are mostly easy to perform and focus on the scapula-retracting muscles and the muscles responsible for external rotation of the shoulder. The treatment program should be executed under the supervision of a therapist at the beginning and later may be performed by the patients themselves.&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;Consensus on a new exercise guideline dedicated to the treatment of functional posterior shoulder instability was achieved. This guideline should not only help to treat this challenging pathology but also provide a starting point for further scientific research and ongoing improvement.&lt;/jats:p&gt;&lt;/jats:sec&gt