Objective Functional posterior shoulder instability (FPSI) (type B1) is a severe type of instability, mainly in teenagers and young adults, that leads to loss of function, pain, and stigmatization among peers. An experimental nonsurgical treatment protocol based on neuromuscular electrical stimulation (NMES) showed very promising early results in the treatment of FPSI. The hypothesis of this study was that NMES-enhanced physical therapy leads to better outcomes than physical therapy alone as the current gold standard of treatment in patients with FPSI. Methods In this multicenter randomized controlled trial, patients with FPSI were randomly allocated in a 1:1 ratio to either 6 weeks of physical therapy or 6 weeks of physical therapy with simultaneous motion-triggered NMES. Baseline scores as well as outcome scores at 6 weeks, 3 months, 6 months, and 12 months after the intervention were obtained. The predefined primary outcome of this trial was the Western Ontario Shoulder Instability Index (WOSI) at the 3-month time point. Results Forty-nine patients were randomized and eligible for the trial. The group that received physical therapy with simultaneous motion-triggered NMES showed a significantly better main outcome measurement in terms of the 3-month WOSI score (64% [SD = 16%] vs 51% [SD = 24%]). Two-thirds of the patients from the physical therapist group crossed over to the group that received physical therapy with simultaneous motion-triggered NMES due to dissatisfaction after the 3-month follow-up and showed a significant increase in their WOSI score from 49% [SD = 8%] to 67% [SD = 24%]. The frequency of instability episodes showed a significant improvement in the group that received physical therapy with simultaneous motion-triggered NMES at the 3-month follow-up and beyond, while in the physical therapist group, no significant difference was observed. Conclusion The current study shows that NMES-enhanced physical therapy led to statistically significant and clinically relevant improvement in outcomes in the treatment of FPSI compared to conventional physical therapy alone—from which even patients with prior unsatisfactory results after conventional physical therapy can benefit. Impact Based on the results of this study, NMES-enhanced physical therapy is an effective new treatment option for FPSI, a severe type of shoulder instability. NMES-enhanced physical therapy should be preferred over conventional physical therapy for the treatment of patients with FPSI.

Arthroscopically assisted stabilization of dislocations of the acromioclavicular joint (ACJ) with suture-button systems enables sufficient anatomical reduction with subsequent ligament healing in the acute phase and primary stability in chronic cases. For correct orthograde positioning of bone tunnels an intraoperative image converter control is recommended in addition to the arthroscopic aiming device. To avoid breakages of the button or fractures of the clavicle or coracoid process, a transclavicular-transcoracoidal bone tunnel with a 2.4 mm cannulated drill with a single implant is recommended. In chronic injuries, in addition to the single implant for primary stability, the autologous tendon graft for coracoclavicular (CC-)ligament augmentation can be circumclavicularly and circumcoracoidally shuttled to avoid further bone tunnels. For reconstruction of the ACJ capsule and for horizontal stabilization, in acute as well as chronic cases an AC cerclage with sutures, tape or graft in addition to coracoclavicular stabilization is biomechanically recommended. A coracoid fracture can be arthroscopically reduced via an anterior portal with a 1.6 mm K-wire and fixed above by a 4.5 mm screw. To reduce the load on the fixed coracoid fracture the addition of a hook plate can be indicated for temporary ACJ stabilization.

Recurrent anterior shoulder instability caused by critical bone loss of the glenoid is a challenging condition for shoulder surgeons. The purpose of this prospective multicenter trial was to compare the arthroscopic transfer of the coracoid process (Latarjet procedure) with the arthroscopic reconstruction of the glenoid using iliac crest autografts. A prospective multi-center trial was performed in nine orthopaedic centres in Austria, Germany and Switzerland between July 2015 and August 2021. Patients were prospectively enrolled and received either an arthroscopic Latarjet procedure or an arthroscopic iliac crest graft transfer. Standardized follow-up after 6 months and mimimum 24 months included range of motion, Western Ontario stability index (WOSI), Rowe score and subjective shoulder value (SSV). All complications were recorded. 177 patients (group Latarjet procedure: n = 110, group iliac crest graft: n = 67) were included in the study. WOSI (n.s.), SSV (n.s.) and Rowe score (n.s.) showed no difference at final follow-up. 10 complications were seen in group Latarjet procedure and 5 in group iliac crest graft; the frequency of complications did not differ between the two groups (n.s.). The arthrosopic Latarjet procedure and arthroscopic iliac crest graft transfer lead to comparable results regarding clinical scores, frequency of recurrent dislocations and complication rates. Level II.

The goal of this study was to compare the Shoulder Pacemaker to the current gold-standard in treatment of functional posterior shoulder instability.

Die arthroskopisch assistierte Stabilisierung von Luxationen des Akromioklavikulargelenks (ACG) mit Faden-Button-Systemen ermöglicht eine suffiziente anatomische Reposition mit konsekutiver Bandheilung im akuten Stadium und Primärstabilität in chronischen Fällen. Zur korrekten orthograden Anlage der Bohrtunnel wird neben dem arthroskopischen Zielgerät eine intraoperative Bildwandlerkontrolle empfohlen. Zur Vermeidung von Button-Ein- oder -Ausbrüchen bzw. Klavikula‑/Korakoidfrakturen wird ein Bohrtunnel mit einem kanülierten 2,4-mm-Bohrer transklavikulär und transkorakoidal mit einem Einzelimplantat empfohlen. Bei der chronischen Verletzung sollte neben dem Einzelimplantat für die Primärstabilität das autologe Sehnengraft für die korakoklaviculäre (CC-)Bandaugmentation zirkumklavikulär und zirkumkorakoidal geshuttelt werden, um hier weitere Bohrkanäle zu vermeiden. Zur Rekonstruktion der ACG-Kapsel und zur horizontalen Stabilisierung ist es biomechanisch sinnvoll im akuten und chronischen Fall eine AC-Zerklage mit Faden oder Tape bzw. Graft additiv zur korakoklavikulären Stabilisierung zu etablieren. Die Korakoidfraktur kann arthroskopisch über ein anteriores Portal mit einem 1,6-mm-K-Draht reponiert und darüber mit einer kanülierten 4,5-mm-Schraube osteosynthetisiert werden. Additiv kann hier eine temporäre ACG-Stabilisierung mit einer Hakenplatte indiziert sein, um den Zug vom fixierten Korakoid zu nehmen.

Purpose To evaluate the clinical outcomes of patients with a minimum 2-year follow-up following contemporary patellofemoral inlay arthroplasty (PFIA) and to identify potential risk factors for failure in a multi-center study. Methods All patients who underwent implantation of PFIA between 09/2009 and 11/2016 at 11 specialized orthopedic referral centers were enrolled in the study and were evaluated retrospectively at a minimum 2-year follow-up. Clinical outcomes included the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, the Knee Injury and Osteoarthritis Outcome Score (KOOS), the Tegner Scale, the visual analogue scale (VAS) for pain, and subjective patient satisfaction. Pre- and perioperative risk factors were compared among failures and non-failures to determine potential risk factors. Results A total of 263 patients (85% follow-up rate) could be enrolled. The mean age at the time of index surgery was 49 ± 12 years with a mean postoperative follow-up of 45 ± 18 months. The overall failure rate was 11% (28 patients), of which 18% (5 patients) were patients with patella resurfacing at index surgery and 82% (23 patients) were patients without initial patella resurfacing. At final follow-up, 93% of the patients who did not fail were satisfied with the procedure with a mean transformed WOMAC Score of 84.5 ± 14.5 points, a mean KOOS Score of 73.3 ± 17.1 points, a mean Tegner Score of 3.4 ± 1.4 points and a mean VAS pain of 2.4 ± 2.0 points. An increased BMI was significantly correlated with a worse postoperative outcome. Concomitant procedures addressing patellofemoral instability or malalignment, the lack of patellofemoral resurfacing at the index surgery and a high BMI were significantly correlated with failure in our patient cohort. Conclusion Patellofemoral inlay arthroplasty shows high patient satisfaction with good functional outcomes at short-term follow-up and thus can be considered a viable treatment option in young patients suffering from isolated patellofemoral arthritis. Patellar resurfacing at index surgery is recommended to decrease the risk of failure. Level of evidence Retrospective case series, Level IV.

Shoulder joint replacement in young patients <50 (55) years old is a great challenge with respect to shoulder function and prosthesis survival, as both are limited. Several studies have shown that total shoulder arthroplasty leads to better clinical results compared to partial endoprostheses concerning pain relief, shoulder function and implant survival, especially in young patients. The cobalt chrome (CoCr) implants commonly used for humeral head replacement in hemiarthroplasty in particular, can cause premature attrition of the glenoid cartilage and bone with medial protrusion and subsequent pain and loss of function. Whether new implant materials, such as as pyrocarbon, aluminium oxide ceramics (Al2O3) or polycarbonate urethane (PCU) can reduce glenoid attrition with a subsequent improvement of function and increased survival of the implant, has been proven in biomechanical studies but not yet in clinical studies. Even a single detachment of the subscapularis tendon during arthrotomy and especially with repeated arthrotomy leads to subscapularis tendon insufficiency. Therefore, even during the primary implantation long-term consideration should be given to partial joint replacements, which are questionable in larger chondral lesions because revisions are to be expected. New elliptical anatomically designed humeral implants and also cemented inlay components and low-profile cementless metallic glenoid implants with a good bony ingrowth without glenohumeral offset enlargement in total shoulder replacement could lead to longer prostheses survival and better shoulder function, particularly in young active patients; however, long-term results of clinical studies are currently not available.

OBJECTIVE:To evaluate the position of the acromioclavicular joint (ACJ) and relation to the critical shoulder angle (CSA) in shoulders with rotator cuff tears (RCT). METHODS:In a matched pair study including 75 shoulders with arthroscopically validated RCT and 75 controls (mean age 59.4 ± 7.9 years) the position of the ACJ in relation to the glenoid and the CSA were measured on true ap radiographs. RESULTS:The CSA is larger (p = 0.0018) and the position of the ACJ is more lateral (p = 0.0016) in shoulders with RCT in comparison to matched controls. CONCLUSION:The more lateral position of the ACJ in shoulders with a large CSA might be an additional component in the multifactorial pathogenesis of RCT.

The acromiohumeral distance is in practice often evaluated on MRI by radiologists and a reduction diagnosed as subacromial impingement. However, the acromiohumeral distance as indicator for a decentered glenohumeral joint is defined on a true AP radiograph with the patient standing or sitting. The present study therefore evaluated the influence of the patient position by comparing the acromiohumeral distance in both modalities in shoulders with an intact rotator cuff. On MRI images and true AP radiographs of patients > 20 and < 80 years with an intact rotator cuff the acromiohumeral distance was measured. The maximum cranio-caudal size of the glenoid was measured as a reference to allow a direct comparison of both modalities. Two-hundred and thirty-four shoulders (mean patients age 45.8 ± 14.3 years) were included. The mean acromiohumeral distance/glenoid size ratio of all shoulders was significantly larger (P < 0.0001) on the MRI with 4.6 ± 1.0 in comparison to 4.1 ± 0.9 in the radiographs indicating a smaller acromiohumeral distance on the MRI. In absolute values, a mean acromiohumeral distance of 9.2 mm ± 1.8 on MRI in comparison to 10.4 mm ± 2.4 on the radiographs was calculated. Herewith, the acromiohumeral distance in the MRI was in the average 1.2 mm ± 2.1 (13%) smaller than the in corresponding radiographs (P < 0.0001). The acromiohumeral distance is significantly smaller in the MRI in comparison to AP radiographs in shoulders with an intact rotator cuff and should not be used as a decision criterion on MRI to assess glenohumeral centering or subacromial space width. IV.

The long head of biceps tendon (LHB) has been evaluated as one of the most important pain generators of the shoulder. In addition, an unstable LHB can cause cartilage lesions of the humerus. For the treatment of LHB lesions, tenodesis or tenotomy has been shown to be appropriate. A well-performed biceps tenodesis provides a lower rate of Popeye-sign deformities compared with tenotomy but must result in low implant complication rates and costs.

ZusammenfassungDer Bizepsmuskel besteht aus einer langen und einer kurzen proximalen und einer distalen Sehne und überspannt das Schulter- und Ellenbogengelenk. Damit stabilisiert er das Schulter- und beugt im Ellenbogengelenk und supiniert den Unterarm. Prädilektionsstellen für Läsionen sind der Ursprung der langen Bizepssehne als SLAP-Läsionen und das Pulley-System, was die Sehne vor dem Eintritt in den Sulcus bicipitalis stabilisiert und der Ansatz der distalen Bizepssehne an der Tuberositas radii. SLAP- und Pulley-Läsionen entstehen oft bei Überkopfaktiven durch Makro- oder repetitive Mikrotraumata, wobei die Abduktions-Außenrotations-Position des Arms für die SLAP, die Flexions-Innenrotations-Position für die Pulley-Läsionen dominiert. SLAP-Läsionen können arthroskopisch anatomisch refixiert werden. Ab einem Patientenalter von 37 Jahren ist die LBS-Tenodese Therapie der Wahl, ebenso für Pulley-Läsionen, wobei hierbei die oft begleitenden Subscapularis- und Suprasinatus-Sehnen-Läsionen mit versorgt werden sollten. Die distal komplett rupturierte Bizepssehne sollte bei körperlich Aktiven anatomisch reinseriert werden.

Der Schultergelenkersatz bei jungen Patienten <50 (55) Jahre stellt hinsichtlich Funktion und Endoprothesenstandzeit eine große Herausforderung dar. Diverse Studien zeigen, dass gerade bei jungen Patienten Schultertotalendoprothesen (Schulter-TEPs) im Vergleich zu Hemiendoprothesen zu besseren klinischen Resultaten hinsichtlich Schmerzreduktion, Funktion und längeren Standzeiten führen. Insbesondere die gängigen Humerusersatzköpfe aus Cobalt-Chrom (CoCr) können bei den Hemiendoprothesen zu einem frühzeitigen Glenoidverschleiß mit medialer Protrusion sowie konsekutiven Schmerzen und Funktionsverlust führen. Ob neue Implantatmaterialien, wie z. B. Pyrocarbon, Aluminiumoxid-Keramik (AL2O3) oder Polycarbonat-Urethan (PCU), hier den Glenoidverbrauch reduzieren und somit eine Verbesserung der Funktion und Standzeiten erbringen, konnte gegenwärtig zwar in biomechanischen Studien gezeigt, in klinischen Studien jedoch noch nicht eindeutig bewiesen werden. Bereits eine einzige Ablösung der Subskapularissehne (SSC) im Rahmen einer Arthrotomie und insbesondere wiederholte Arthrotomien führen zu SSC-Insuffizienzen, weshalb schon bei der Erstimplantation langfristig gedacht werden sollte. Dies stellt fokale Gelenkersatzoperationen bei größeren Knorpelschäden in Frage, da hier Revisionsoperationen zu erwarten sind. Neue anatomisch-elliptisch geformte Humerusimplantate sowie auch zementierte Inlay- oder wenig auftragende zementfrei einwachsende metallische Glenoidimplantate ohne glenohumerale Offset-Vergrößerung bei Schulter-TEPs erbringen möglicherweise eine Verbesserung der Endoprothesenstandzeiten und Funktion gerade bei jungen aktiven Patienten. Langzeitstudien hierzu stehen allerdings noch aus.