[Diagnostics and treatment of posterior shoulder instability]. / Diagnostik und Therapie der posterioren Schulterinstabilität.

Posterior shoulder instability has a markedly lower incidence than anterior shoulder instability. It has a wide spectrum of clinical symptom manifestations and the overwhelming number of patients lack a traumatic primary dislocation. In addition to a detailed medical history, a specific clinical examination with the help of standardized provocation tests is essential for the diagnostics. For the detection of structural posterior capsule and labral lesions in cases of chronic courses, magnetic resonance imaging (MRI) should be used with an intra-articular contrast agent. Relevant bony defects of the humeral head (reverse Sachs-Hill lesion) are frequent, whereas critical posterior defects of glenoid cavity are relatively rare. Both lesions should be quantified using 3D computed tomography. The choice of therapeutic procedure should be based on the underlying pathology of the defect. Conservative therapy is useful in patients with scapular dyskinesis, voluntary dislocation and pathological muscle patterning. In isolated soft tissue pathologies, arthroscopic labrum fixation and capsule plication are the standard treatment. In the case of insufficient soft tissue relations or critical posterior glenoid defects, bony stabilization of the glenoid using an iliac crest bone graft is the recommended therapy.

Results of an open posterior bone block procedure for recurrent posterior shoulder instability after a short- and long-time follow-up.

PURPOSE: The aim of the present study was to analyse and compare the clinical and radiological results after open posterior bone block procedure at long- (LT) and short-term (ST) follow-up. The hypothesis was that placement of a bone block at the posterior glenoid rim in a technique of extending the glenoid surface will create permanent joint stability even in cases with hyperlaxity without a clinically relevant loss of motion or increase in osteoarthritis. METHODS: Fifteen consecutive shoulders with recurrent posterior dislocation were evaluated clinically and radiologically. The Rowe score, Western Ontario Shoulder Index, Walch-Duplay score and the Constant-Murley score were used for clinical evaluation. The patients were categorized according to their follow-up period as either ST follow-up (min 12 months) or LT follow-up (min 42 months). RESULTS: The clinical results showed no significant difference between ST (9) and LT (6) with good to very good overall results in the subjective as well as the objective scores (CS, RS, WDS). At LT, most patients felt mild to minor pain under strain. The difference in pain between the groups was not significant. Active ranges of motion and strength assessments were normal in all cases. In one case, recurrent dislocations occurred after bone graft resorption 6 months post-operatively. Only one patient presented mild osteoarthritis, without further progress at follow-up. CONCLUSION: The open posterior bone block procedure can be a successful treatment option for recurrent posterior shoulder instability at ST and LT follow-up. This series showed a low rate of recurrent dislocations without development or progression of osteoarthritis. Since soft tissue procedures do not always provide satisfying results, the posterior bone block augmentation presents a reliable technique for the treatment of symptomatic posterior instability. LEVEL OF EVIDENCE: Case Series, Treatment Study, Level IV.

The biomechanical influence of the deltotrapezoid fascia on horizontal and vertical acromioclavicular joint stability.

INTRODUCTION: Many studies have investigated the biomechanical influence of the acromioclavicular (AC) and coracoclavicular (CC) ligaments on the stability of the acromioclavicular joint (ACJ). It has been shown that augmentation of the CC ligaments alone can result in residual horizontal instability. Our hypothesis was that the DTF would have a significant stabilizing effect on horizontal ACJ stability. MATERIALS AND METHODS: In a biomechanical in vitro study a sequential injury of the ACJ was created on eight shoulders from full body, which were placed in an upright sitting position. The translation and rotation of the clavicle were measured in relation to the acromion using an optical navigation system in various states during thoracic-humeral elevation, abduction, and horizontal adduction. The three states were: an intact shoulder, complete sectioning of the AC ligaments, and a circular lesion of the DTF. RESULTS: Compared to the intact state we found a significant increase in anterior rotation of the clavicle of 1.11° (p = 0.012) and a tendency in lateral translation of 2.71 mm (p = 0.017) in relation to the acromion, with a combined lesion of AC ligaments and DTF. No significant differences were found between the intact state and the isolated dissected AC ligaments as well in adduction as elevation. CONCLUSION: A combined lesion of the AC ligaments and the DTF resulted in a quantitatively small but significant increase in anterior rotation and a tendency in lateral translation of the clavicle in relation to the acromion. These differences were quantitatively small, so that the clinical relevance of the stabilization effect of combined AC ligaments and DTF injuries is questionable.

[Diagnostics and treatment of anterosuperior rotator cuff tears]. / Diagnostik und Therapie anterosuperiorer Rotatorenmanschettenläsionen.

INTRODUCTION: Anterosuperior rotator cuff lesions are defined as combined tears of the subscapularis and the supraspinatus tendon and are usually accompanied by an associated lesion of the rotator interval. There are three different types of lesion: extended lesions of the biceps pulley, transmural tears of the supraspinatus with an associated partial lesion of the subscapularis tendon, and massive anterosuperior rotator cuff tears. None of these lesions responds well to physiotherapy because of biceps tendon instability. Therefore, surgical treatment is required, including tenodesis or tenotomy of the biceps tendon and additional repair of the rotator cuff. Deep partial tears of the subscapularis or the supraspinatus tendon (≥ 6 mm) should be refixed as well. Massive anterosuperior rotator cuff tears should be treated immediately because of the high retraction tendency of the subscapularis tendon.

[Stability versus mobility of the shoulder. Biomechanical aspects in athletes]. / Stabilität versus Mobilität der Schulter. Biomechanische Aspekte beim Sportler.

The demand profile of athletes shoulders is high. On the one hand the shoulder has to provide a maximum active range of motion that allows rapid movements of the arm and on the other hand it has to be sufficiently stabilized to decelerate rapid movements and to neutralize the resulting translational forces. Two general types of instability can be differentiated in athletes shoulders: the macroinstability typically occurring in athletes involved in contact sports and the microinstability occurring in athletes involved in overhead sports.Repetitive abduction and external rotation movements of athletes involved in overhead sports lead to adaptation of the glenohumeral joint capsule and ligaments. The anterior capsule becomes stretched while the posterior capsule develops tightness. These adaptations can result in an anterior microinstability as well as posterosuperior impingement (PSI) which implicates a pathological contact of the posterosuperior rotator cuff with the posterior glenoid and which is also associated with SLAP lesions. In contrast the shoulders of swimmers are prone to anterosuperior impingement because the arm stroke involves a forceful combined anteflexion, adduction and internal rotation of the arm.The macroinstability of contact athletes is caused by sufficient trauma and characterized by a structural lesion of capsulolabral or bony lesion. While the empirical recurrence risk of young contact athletes is already high, it can be further impaired by bony defects of the glenoid. In suspected cases, critical glenoid defects should be quantified by computed tomography (CT) scans and treated by bony augmentation of the glenoid.

[Instability pattern of acromioclavicular joint dislocations type Rockwood III: relevance of horizontal instability]. / Instabilitätsmuster bei Akromioklavikulargelenkverletzungen vom Typ Rockwood III: Bedeutung der horizontalen Instabilität.

BACKGROUND: There is no evidence-based treatment algorithm established for acromioclavicular joint (AC joint) dislocation classified as type Rockwood III injury. Recent meta-analyses revealed no advantage of surgical treatment compared to the non-operative approach. Both surgical and non-surgical approaches have been reported with inconsistent results. Therefore, the hypothesis of the current study was that patients classified as having Rockwood grade III injury may have different degrees of horizontal AC joint instability. MATERIAL AND METHODS: A total of 18 consecutive patients who had sustained a dislocation of the AC joint classified as Rockwood III were evaluated radiologically to quantify the horizontal instability of the AC joint. The specific radiological investigation included lateral stress x-rays (Alexander view) und axial stress x-rays with the affected arm in a horizontal adduction position. RESULTS: The dynamic horizontal instability of the AC joint was found to be independent of the vertical dislocation measured in the Rockwood classification. CONCLUSION: For further treatment studies Rockwood III injuries should be distinguished in patients presenting with or without a substantial horizontal AC joint instability.

Biomechanical investigation of the stabilization principle of the Latarjet procedure.

PURPOSE: The purpose of the study was to determine the biomechanical status of the different components of the Latarjet procedure. The anterior capsule reconstruction with the transferred coracoacromial ligament (CAL) and the necessity of an intact subscapularis tendon were of particular interest. We hypothesized that the anterior capsule reconstruction will have a significant effect and that the Latarjet procedure will lose its stabilizing effect if the subscapularis tendon is torn. METHODS: Stability testing of 12 human shoulder specimens was performed. After testing of the intact joint, a combined anterior glenoid and capsule defect was set arthroscopically. Then the Latarjet procedure was performed using an open approach and tested with and without loading of the conjoint tendons (10 N). Afterwards, the specimens were distributed into two groups and the Latarjet technique was reduced stepwise: dissection of the CAL, dissection of the conjoint tendons (group A); reduction of the coracoid segment, dissection of the subscapularis tendon (group B). Biomechanical testing was performed for each condition in two positions: 60° of glenohumeral abduction with neutral rotation and with 60° of external rotation; each with a passive humerus load of 30 N in the anterior, inferior and anteroinferior direction. RESULTS: The Latarjet technique with load applied to the conjoint tendons significantly reduced translation compared with the defect condition for all tested positions in all directions. In group A, the CAL-dissection led to a significant increase of anterior translation (+5.0 mm, p = 0.003) and inferior translation (+7.3 mm, p = 0.025) in neutral rotation and of anterior translation in 60° of external rotation (+4.4 mm, p = 0.034). In group B, the reduction of the coracoid bone down to the coracoid tip resulted in a significant increase of only the anterior translation in abduction and 60° of external rotation (+4.5 mm, p = 0.05). In contrast, the detachment of the subscapularis tendon led to a significant increase of translation in all testing positions except the inferior direction in the neutral rotation. CONCLUSIONS: We found the anterior capsule reconstruction to represent a significant contribution to the stabilizing effect of the Latarjet procedure, whereas a deficiency of the subscapularis tendon eliminates its effect. CLINICAL RELEVANCE: We recommend to perform the Latarjet technique with an anterior capsule reconstruction (e.g. CAL transfer) and with a transfer of the coracoid bone block rather than a transposition of the coracoid tip. Furthermore, we were able to show that an intact subscapularis tendon is a necessary prerequisite for a reliable stabilization.

[Epidemiology, anatomy, biomechanics and imaging of acromioclavicular joint injuries]. / Epidemiologie, Anatomie, Biomechanik und Bildgebung von Akromioklavikulargelenkverletzungen.

Current techniques of acromioclavicular (AC) joint repair primarily focus on the reconstruction of the coracoclavicular (CC) ligaments. However, it is not clear if this approach is sufficient to restore vertical as well as horizontal AC joint stability and kinematics. This review focuses on the epidemiology of AC joint injuries and the coincidence of intra-articular pathologies. Furthermore, the clinically relevant anatomy and the pathomechanism of AC joint instability are described. The biomechanical characteristics of current procedures as they have been revealed by in vitro investigations are summarized. As a basic result, neither selective repair of the CC ligaments nor selective repair of the AC ligaments could be shown to restore both vertical and horizontal joint stability. Similar to the intact ligaments CC repair primarily provides vertical joint stability while AC repair is able to restore horizontal stability. In conclusion a biomechanically effective treatment of AC joint separation should analyze the individual instability pattern in the first step. Therefore, the radiological standard according to Rockwood should be supplemented by specific stress x-rays for quantification of dynamic horizontal AC joint instability. In the second step an adequate surgical treatment considering CC and AC stabilization should be performed meeting the individual patient requirements.

Colonic perforation in a right atraumatic diaphragmatic hernia.

SUMMARY: A 38-year female with no prior medical or surgical history presented with pleuritic pain and respiratory distress. Imaging revealed a right diaphragmatic hernia with colonic content. At right anterolateral thoracotomy, a diaphragmatic hernia containing a perforated right hemi-colon was found. The colon was resected in the chest and continuity restored via a laparotomy. This case illustrates the risk of obstruction, ischaemia and perforation and highlights the importance of early identification and prompt surgical management to reduce morbidity and mortality.

Effective discrimination of gas-phase peptide conformers using TIMS-ECD-ToF MS/MS.

In the present work, four, well-studied, model peptides (e.g., substance P, bradykinin, angiotensin I and AT-Hook 3) were used to correlate structural information provided by ion mobility and ECD/CID fragmentation in a TIMS-q-EMS-ToF MS/MS platform, incorporporating an electromagnetostatic cell (EMS). The structural heterogeneity of the model peptides was observed by (i) multi-component ion mobility profiles (high ion mobility resolving power, R ∼115-145), and (ii) fast online characteristic ECD fragmentation patterns per ion mobility band (∼0.2 min). Particularly, it was demonstrated that all investigated species were probably conformers, involving cis/trans-isomerizations at X-Pro peptide bond, following the same protonation schemes, in good agreement with previous ion mobility and single point mutation experiments. The comparison between ion mobility selected ECD spectra and traditional FT-ICR ECD MS/MS spectra showed comparable ECD fragmentation efficiencies but differences in the ratio of radical (˙)/prime (') fragment species (H˙ transfer), which were associated with the differences in detection time after the electron capture event. The analysis of model peptides using online TIMS-q-EMSToF MS/MS provided complementary structural information on the intramolecular interactions that stabilize the different gas-phase conformations to those obtained by ion mobility or ECD alone.

Mid- and long-term results of the joint preserving therapy of hallux rigidus.

BACKGROUND: The hallux rigidus is an over 100-year-known pathology. Yet an overall accepted therapy regime does not exist. The aim of this prospective study was to analyze the long-term clinical outcome and patient satisfaction of joint preserving operative care in patients with symptomatic hallux rigidus. METHODS: We present a prospective study with 60 patients (60 feet) with symptomatic hallux rigidus. In cases with intraoperative dorsiflexion of less than 70 degrees after the cheilectomy, an additional Kessel-Bonney osteotomy was done. The first follow-up after 24 (10-31) months was done on 49 (81.7%) patients and the second after 96 (84-104) months on 46 (76.7%) patients. We recorded the pre- and post-operative Kitaoka score, range of motion, pain and patients satisfaction. The results were related to the operative procedure and the grade of hallux rigidus (according to Regnauld). RESULTS: Twenty patients were graded as I, 35 patients as II and 5 patients as III. At the follow-up, the mean dorsiflexion increased in grade I patients to about 21.7 degrees , in grade II patients about 23.7 degrees and in grade III patients about 26.3 degrees . At the first follow-up [24 (10-31) months], all patients of grade I, 63.3% patients of grade II and 75% of grade III patients had just occasional or no pain. At the second follow-up [96 (84-104) months], 77.8% of grade I and 73.9% of grade II patients had no pain. At the first (second) follow-up 53.3% (61.1%) of grade I, 43.3% (33.3%) of grade II and 50% (25%) of grade III patients were completely satisfied. In order to the operative procedure the patients were completely satisfied or satisfied: first (second) follow-up 52% (85.9%) of patients with cheilectomy and 85% (86.4%) of patients with cheilectomy and Kessel-Bonney osteotomy. In 51.4% of the patients, the Kitaoka Score was higher than 70.4 points. Four patients had a persistent hypaesthesia of the medial side of the great toe and three patients had a delayed wound healing. No revision was necessary. No further operation was done in all the investigated patients. CONCLUSION: The joint preserving operation in patients with grade I and II hallux rigidus shows an increase of dorsiflexion and decrease of daily pain. The long-term follow-up shows a persistent pain reduction and satisfaction of the patients. Our results recommend a joint preserving operation in grade I and II hallux rigidus. An additional osteotomy of the proximal phalanx should be done in cases of dorsiflexion less than 70 degrees after cheilectomy.

[Update on shoulder surgery 2010: current treatment strategies for traumatic lesions of the shoulder]. / Update Schulterchirurgie 2010 : Aktuelle Therapiestrategien bei Verletzungen des Schultergürtels.

The article summarizes the basic literature findings and innovations in the treatment of traumatic shoulder lesions published during the last 3 years. It covers trends in acromioclavicular joint dislocation, traumatic shoulder instability, rotator cuff tears as well as fractures of the humeral head. In particular prospective clinical studies with a high level of evidence are cited, which concern about the outcome of surgical and non-surgical treatment methods and the optimal point for treatment. The aim of this review is therefore to provide direct implications for the clinical treatment algorithm of such lesions.

[Impact of hypothermia on the severely injured patient]. / Bedeutung der Hypothermie in der Traumatologie.

Accidental hypothermia is a common complication in severely injured patients. Risk factors include environmental exposure of the patient at the accident site or in the clinic, infusion of cold fluids, hemorrhagic shock and anesthetics which influence thermoregulation. In contrast to animal studies, human studies and clinical experiences have identified accidental hypothermia of the severely injured patient to be associated with increased complication and mortality rates. As a consequence, hypothermia together with acidosis and coagulopathy, have been coined the lethal triad in severely injured patients. On a cellular level hypothermia reduces cellular activity and metabolism resulting in reduced oxygen consumption, which is therapeutically used in patients following cardiac arrest. However, the activity of important enzymes, such as those of the coagulation pathway, is simultaneously down regulated. Hypothermia-induced coagulopathy, which is refractory to substitution of coagulation factors, is a major complication of hypothermia in traumatized patients. Therefore, hypothermic trauma patients with hemodynamic instability require aggressive rewarming.

The stabilization effect of the conjoint tendon in reverse total shoulder arthroplasty.

BACKGROUND: Numerous factors determine stability of reverse total shoulder arthroplasty. The effect of the conjoint tendon in relation to stability remains unknown. In this biomechanical study, we evaluated the influence of the conjoint tendon on the anterior stability of reverse total shoulder arthroplasty with a hemispherical glenosphere and a glenosphere with 9 mm lateralisation. METHODS: A reverse total shoulder arthroplasty was implanted in 6 human cadaveric shoulders. The anterior stability was evaluated using a shoulder simulator. Two conditions, intact and dissected conjoint tendon, and 2 component configurations, a hemispherical glenosphere and a glenosphere with 9 mm lateralisation, were tested in each specimen. Testing of anterior stability was performed in 30° and 60° of abduction, with 0° and 30° of external rotation in the glenohumeral joint. FINDINGS: The conjoint tendon showed a significant influence on the anterior stability with a hemispherical glenosphere in 30° and 60° with neutral rotation (p = 0.028) as well as 30° abduction with 30° (p = 0.028) external rotation. The 9 mm lateralised glenosphere stabilized significantly reverse total shoulder arthroplasty with resected conjoint tendon compared to the hemispherical glenosphere with resected conjoint tendon (p = 0.028). INTERPRETATION: In a biomechanical setting the conjoint tendon has a stabilizing influence on the anterior stability of the reverse total shoulder arthroplasty with a hemispherical glenosphere in an abducted arm position, but this stabilizing effect was not seen with the lateralised glenosphere. The single influence of the lateralisation of the glenosphere on anterior stability was shown in cases of resected conjoint tendon.

Transfer of the long head of biceps to the conjoint tendon. A biomechanical study.

BACKGROUND: Tenodesis of the long head of biceps has been intensively investigated and various surgical options exist. The aim of this biomechanical study was to compare the maximum strength of two different techniques for biceps tenodesis. Our hypothesis was that the two procedures have the same biomechanical properties. METHODS: We performed the two different tenodesis techniques using 12 fresh frozen shoulders divided into two groups of six. In the first group, the biceps was transferred to the conjoint tendon. In the second group, an intraossous suprapectoral tenodesis was performed. After a preload of 10 N, cyclical loading with a maximum of 60 N and 100 N with 100 cycles and 0.5 Hz was applied to the tendons for both groups. An axial ultimate loading to failure was conducted subsequently. RESULTS: No significant differences were found in age, bone mineral density, or weight between the two groups. During the cyclical loading with 60 N, one slippage of the tendon was observed in the suprapectoral group. The mean ultimate load to failure was 294.15N in the transposition group and 186.76 N in the suprapectoral group, but this difference was not significant (P=0.18). INTERPRETATION: The biomechanical results demonstrated equal biomechanical properties postoperatively for both transposition of the tendon and the current standard suprapectoral tenodesis procedure. The transposition can be performed as a primary or a salvage procedure in order to potentially reduce the proportion of patients with persistent postoperative bicipital groove pain and is comparable in strength to a standard tenodesis.

Comparison of various types of stiffness as predictors of the load-bearing capacity of callus tissue.

The ability to predict load-bearing capacity during the consolidation phase in distraction osteogenesis by non-invasive means would represent a significant advance in the management of patients undergoing such treatment. Measurements of stiffness have been suggested as a promising tool for this purpose. Although the multidimensional characteristics of bone loading in compression, bending and torsion are apparent, most previous experiments have analysed only the relationship between maximum load-bearing capacity and a single type of stiffness. We have studied how compressive, bending and torsional stiffness are related to the torsional load-bearing capacity of healing callus using a common set of samples of bone regenerate from 26 sheep treated by tibial distraction osteogenesis. Our findings showed that measurements of torsional, bending and compressive stiffness were all suitable as predictors of the load-bearing capacity of healing callus. Measurements of torsional stiffness performed slightly better than those of compressive and bending stiffness.

[Arthroscopic posterior shoulder stabilization with an iliac bone graft and capsular repair]. / Arthroskopische posteriore Schulterstabilisierung mit Knochenblock und Kapselrekonstruktion.

OBJECTIVE: Arthroscopic posterior shoulder stabilization with an iliac bone graft and capsulolabral repair, which should combine the pre-existing open procedure with the advantages of improved arthroscopic visualization. INDICATIONS: Posterior instability with concomitant pathologies (e.g. capsular insufficiency, posterior Bankart lesion, posterior glenoid dysplasia) and recurrent posterior instability after failed soft tissue reconstruction. CONTRAINDICATIONS: Instability osteoarthritis, locked posterior shoulder dislocation, large reverse Hill-Sachs lesion, extended posterior defect of the glenoid. SURGICAL TECHNIQUE: After arthroscopic evaluation of the shoulder joint and treatment of concomitant pathologies, a tricortical bone graft is harvested from the iliac crest. The posterior capsule is arthroscopically detached from the labrum and the posterior deltoid and rotator cuff are split in line of the muscle fibers. Then the bone graft is positioned and fixed to the posterior scapular neck as an extension of the articular glenoid surface. Thereafter, capsular reconstruction is performed after insertion of suture anchors in the posterior glenoid rim. POSTOPERATIVE MANAGEMENT: During the first 6 weeks 60° of abduction and flexion are permitted without any rotation and full range of motion is developed gradually. Internal rotation is allowed after 8 weeks and return to sports after 12 weeks. RESULTS: For posterior shoulder instability 13 of these operations were performed in our hospital since 2011. Until now, no recurrent instability was observed. After remodelling of the graft, one patient complained about posterior soft tissue irritation so the screws were removed.

[Glenohumeral arthrolysis of the osteoarthritic shoulder in anatomical total shoulder arthroplasty]. / Glenohumerale Arthrolyse der Omarthroseschulter bei anatomischer Schulterprothesenimplantation.

AIM OF THE OPERATION: Pain reduction and improvement of range of motion. INDICATIONS: Primary and secondary osteoarthritis, unsuccessful conservative treatment, limited range of motion with capsular contraction. CONTRAINDICATIONS: General contraindications for anatomical total shoulder arthroplasty. Instability arthritis without capsular contraction. OPERATIVE TECHNIQUE: Deltopectoral approach. Detachment and release of the subscapularis tendon at the lesser tuberosity, incision of the anterior and inferior humeral sided capsule and osteophyte removal, humeral head resection and stem preparation. Glenoid exposure, capsular an labral resection. Glenoid surface preparation and prosthetic component implantation. Anatomical placement of the the humeral head without overstuffing. Implantation of the final humeral stem. Transosseous refixation of the subscapularis tendon. Wound closure. FOLLOW-UP TREATMENT: Abduction brace for 4 weeks. Assisted motion starting the first postoperative day during the first 6 weeks: anteversion/ retroversion 90-0-0°, abduction/ adduction 90-0-20°, internal/external rotation 90-0-individual limitation. Subsequent development of full range of motion. RESULTS: In 2009 and 2010 anatomical total shoulder arthroplasty with glenohumeral arthrolysis was performed in 53 cases. At an average follow up of 32 months the Constant score and range of motion improved significantly. The complication rate was 9%.