Inflammatory tissue response in human soft tissue is caused by a higher particle load near carbon fiber-reinforced PEEK compared to titanium plates.

Titanium as the leading implant material in locked plating is challenged by polymers such as carbon fiber-reinforced polyetheretherketone (CFR-PEEK), which became the focus of interest of researchers and manufacturers in recent years. However, data on human tissue response to these new implant materials are rare. Osteosynthesis plates and peri­implant soft tissue samples of 16 healed proximal humerus fractures were examined (n = 8 CFR-PEEK, n = 8 titanium). Soft tissue was analyzed by immunohistochemistry and µCT. The entrapped foreign bodies were further examined for their material composition by FTIR. To gain insight into their origin and formation mechanism, explanted and new plates were evaluated by SEM, EDX, profilometry and HR-CT. In the peri­implant soft tissue of the CFR-PEEK plates, an inflammatory tissue reaction was detected. Tissues contained foreign bodies, which could be identified as tantalum wires, carbon fiber fragments and PEEK particles. Titanium particles were also found in the peri­implant soft tissue of the titanium plates but showed a less intense surrounding tissue inflammation in immunohistochemistry. The surface of explanted CFR-PEEK plates was rougher and showed exposed and broken carbon fibers as well as protruding and deformed tantalum wires, especially in used screw holes, whereas scratches were identified on the titanium plate surfaces. Particles were present in the peri­implant soft tissue neighboring both implant materials and could be clearly assigned to the plate material. Particles from both plate materials caused detectable tissue inflammation, with more inflammatory cells found in soft tissue over CFR-PEEK plates than over titanium plates. STATEMENT OF SIGNIFICANCE: Osteosynthesis plates are ubiquitously used in various medical specialties for the reconstruction of bone fractures and defects and are therefore indispensable for trauma surgeons, ENT specialists and many others. The leading implant material are metals such as titanium, but recently implants made of polymers such as carbon fiber-reinforced polyetheretherketone (CFR-PEEK) have become increasingly popular. However, little is known about human tissue reaction and particle generation related to these new implant types. To clarify this question, 16 osteosynthesis plates (n = 8 titanium and n = 8 CFR-PEEK) and the overlying soft tissue were analyzed regarding particle occurrence and tissue inflammation. Tissue inflammation is clinically relevant for the development of scar tissue, which is discussed to cause movement restrictions and thus contributes significantly to patient outcome.

Open reduction and internal fixation of displaced head-split type humeral fractures and role of the rotator-interval approach.

Background: Open reduction and internal fixation (ORIF) of humeral head split fractures is challenging because of high instability and limited visibility. The aim of this retrospective study was to investigate the extend of the approach through the rotator interval (RI) on the reduction quality and functional outcome. Methods: 37 patients (mean age: 59 ± 16 years,16 female) treated by ORIF through a standard deltopectoral (DP) approach were evaluated. The follow-up period was at least two years. In 17 cases, the approach was extended through the RI. Evaluation was based on radiographs, Constant scores (CS) and DASH scores. Results: In group DP, "anatomic" reduction was achieved in 9 cases (45%), "acceptable" in 5 cases (25%), and "malreduced" in 6 cases (30%). In group RI, "anatomic" reduction was seen in 12 cases (71%), "acceptable" in 5 cases (29%), and "malreduced" in none (p = 0.04). In the DP group, the CS was 60.2 ± 16.2 and the %CS was 63.9 ± 22.3, while in the RI group, the CS was 74.5 ± 17.4 and the %CS was 79.1 ± 24.1 (p = 0.07, p = 0.08). DASH score was 22.8 ± 19.5 in DP compared to RI: 25.2 ± 20.6 (p = 0.53). Conclusions: The RI approach improves visualization as it enhances quality of fracture reduction, however functional outcomes may not differ significantly. Type of study and level of proof: Retrospective, level III.

Functional outcomes before and after implant removal in patients with posttraumatic shoulder stiffness and healed proximal humerus fractures: does implant material (PEEK vs. titanium) have an impact? - a pilot study.

BACKGROUND: Posttraumatic shoulder stiffness remains a problem after proximal humerus fracture (PHF) despite good healing rates. The aim of this pilot study was to determine whether the implant material and overlying soft tissue have an effect on shoulder range of motion (ROM) before and after implant removal (IR). METHODS: 16 patients (mean age 55.2 ± 15.3 (SD) years; 62.5% female) were included who underwent operative treatment with locking plates of either carbon fiber reinforced Polyetheretherketone (PEEK) (PEEKPower® humeral fracture plate, Arthrex, Naples, Florida, USA, n = 8) or titanium alloy (Ti) (Philos®, DePuy Synthes, Johnson & Johnson Medical, Raynham, Massachusetts, USA, n = 8) for PHF. All patients presented with a limited ROM and persistent pain in everyday life after the fracture had healed, whereupon IR was indicated. ROM before and after IR were compared as well as the Constant Score (CS) and the CS compared to the contralateral shoulder (%CS) 1 year after IR. RESULTS: In group PEEK, elevation was 116.3° ± 19.2° pre- and 129.4° ± 23.7° post-IR (p = 0.027). External rotation was 35.0° ± 7.6° pre- and 50.6° ± 21.8° post-IR (p = 0.041). External rotation with the humerus abducted 90° was 38.8° ± 18.1° pre- and 52.5° ± 25.5° post-IR (p = 0.024). In group Ti, elevation was 110.0° ± 34.6° pre- and 133.8° ± 31.1° post-IR (p = 0.011). External rotation with the humerus at rest was 33.8° ± 23.1° pre- and 48.8° ± 18.7° post-IR (p = 0.048). External rotation with the humerus abducted 90° was 40.0° ± 31.6° pre- and 52.5° ± 22.5° post-IR (p = 0.011). Comparison of the two implant materials showed no significant difference. The overall CS was 90.3 ± 8.8, the %CS was 91.8% ± 14.7%. CONCLUSION: There was no significant difference in ROM, CS and %CS with respect to plate materials, although lower cell adhesion is reported for the hydrophobic PEEK. However, all patients showed improved functional outcomes after IR in this pilot study. In patients with shoulder stiffness following locked plating for PHF, implants should be removed and open arthrolysis should be performed, independently from the hardware material. LEVEL OF EVIDENCE: II.

Varus malposition relates to functional outcomes following open reduction and internal fixation for proximal humeral fractures: A retrospective comparative cohort study with minimum 2 years follow-up.

BACKGROUND: The aim of this study was to evaluate functional outcomes in patients with varus malposition following open reduction and internal fixation of displaced proximal humeral fractures. METHODS: Data of 685 patients with a mean age of 67±15.8 years (67% female), that were treated by open reduction and internal fixation for a displaced proximal humeral fracture at a level 1 trauma center, were analyzed. On standardized x-ray imaging, the degree of varus displacement was measured over a minimum of two years follow-up and patients were divided into three groups. Group A: anatomic or <10° of varus or valgus malposition, group B: 10-20° of varus malposition and group C: >20° varus malposition, while anatomic head-shaft-angle was defined 135° The groups were compared with regards to functional outcomes by means of the Constant Score (CS). RESULTS: In 565 patients with anatomic to minor <10° varus or valgus malposition (Group A), the mean CS was 72.5 ± 18.8 points. The %CS to the uninjured side was 87.2 ± 24.1 and the age and gender normalized nCS was 84.7 ± 21.7. In comparison, in group B (10-20° varus) the mean CS was 64.7 ± 16.9, the mean %CS was 84.5 ± 18.3 and the mean nCS was 76.2 ± 20.6. In group C (>20° varus) the mean CS was 54.1 ± 19.5, the mean was %CS: 72.3 ± 26.4 and the mean nCS was 64.8 ± 23.8 (p = 0.02, p = 0.03, p = 0.01). Overall, the CS, %CS and nCS correlated significantly with the degree of varus position (Pearson correlation, r = 0.23, r = 0.21, r = 0.25). CONCLUSION: Varus malposition is related to inferior functional outcomes compared to anatomic healing in patients treated by open reduction and internal fixation for proximal humeral fractures. The data supports suggestions to prevent varus malposition in open reduction and internal fixation. In severe >20° of varus malposition, revision surgery should be considered.

[Rotator cuff tear : Indications and pathology-specific reconstructive procedures]. / Rotatorenmanschettenruptur : Indikationen und pathologiespezifische rekonstruktive Verfahren.

Rotator cuff (RC) tears comprise a broad spectrum of lesions ranging from partial to full thickness tears of a single tendon and massive cuff tears. Both glenohumeral trauma as well as degenerative processes can result in tearing of the RC. Treatment therefore requires a meticulous diagnosis as well as a differentiated approach by careful consideration of morphological and patient-specific factors. The pathogenesis, tear morphology, clinical symptoms and functional demands of the patient determine the therapeutic approach. Despite pathological and individual patient-related factors, early surgical repair is generally recommended for traumatic RC tears in young patients and in patients with high functional demands due to the high risk of tear progression. The results of RC repair are negatively correlated with the size of the lesion, the number of tendons involved, the degree of tendon retraction, muscular alteration and patient age. This article provides an overview of the various pathogenesis, indications and surgical repair of RC tears with respect to modern pathology-specific reconstructive procedures.

[Principles of tendon healing at the shoulder and consequences for their treatment : Importance of platelet-rich plasma and regenerative medicine]. / Grundlagen der Sehnenheilung an der Schulter und Konsequenzen für ihre Therapie : Stellenwert des plättchenreichen Plasmas und regenerativer Medizin.

Tendon pathologies are a frequent cause of shoulder pain and can lead to significant decline in the quality of life. Conservative treatment is suitable for most tendon pathologies. In addition to classical conservative treatment options, such as physiotherapy, oral analgesia and infiltrations, there are a number of additive treatment options to promote structural tendon healing and clinical outcome. Furthermore, there are approaches to improve the results of the surgical treatment of tendon injuries by biological augmentation. The objective of this article is to give an overview of biological and regenerative therapeutic options in the treatment of tendon injuries of the shoulder. Therefore, the anatomical and molecular biological principles of the tendon structure and their importance for tendon healing are explained in order to highlight the various therapeutic options for daily practice. Biological augmentation procedures and regenerative medicine represent a promising therapeutic option for tendon injuries of the shoulder, however, the benefits are so far supported by little or no evidence at all.

[Arthroscopic soft tissue stabilization of posttraumatic anterior shoulder instability : Techniques, limitations and long-term results]. / Arthroskopische Weichteilstabilisierung der posttraumatischen ventralen Schulterinstabilität : Techniken, Limitationen und Langzeitergebnisse.

Arthroscopic soft tissue stabilization is a well-established and broadly accepted procedure to treat posttraumatic shoulder instability. Advantages in comparison to open stabilization procedures include improved visualization of the structural damage and a less invasive approach. Technical developments in recent years have led to further improvement of the arthroscopic technique for shoulder instability. This article presents a description of principles and new developments as it contains basic techniques including patient positioning, access portals, preparation of the glenoid bone, soft tissue handling and shuttle techniques. Modern suture anchor systems to achieve arthroscopic stabilization with the corresponding advantages and disadvantages are also presented. Furthermore, the limitations and long-term results of arthroscopic soft tissue stabilization are discussed.

[Triceps tendon rupture : Double-row repair and overview of alternative techniques]. / Trizepssehnenruptur : Reinsertion am Olekranon in Doppelreihentechnik und Übersicht alternativer Techniken.

Triceps tendon rupture is a rare injury. While partial tendon ruptures can be treated non-operatively, complete ruptures are an indication for surgical treatment in order to restore strength and a full range of motion. Although many different methods have been published, there is no consensus on the optimal surgical technique.We report the case of a patient who suffered from a complete triceps rupture after a fall. The injury was treated by open reduction and refixation of the tendon using the double-row technique. The following article describes the technique and highlights its advantages and disadvantages in comparison to other procedures.

Management of prehospital shoulder dislocation: feasibility and need of reduction.

PURPOSE: Dislocation of the shoulder is rare in the prehospital setting. The medical specialities of the emergency physicians are heterogeneous, and the level of experience is different. Aim of this study was to evaluate the feasibility, sufficiency, and need of prehospital reduction. METHODS: Over 12 months, 16 rescue stations in Germany and Austria documented cases. Points of examination were: incidence of reduction, influence of pathological findings, therapy and effectiveness of reduction. RESULTS: We included 70 patients. A reduction was undertaken in n = 47 (66.6 %). In n = 70 (100 %) perfusion was without pathological finding after reduction, all n = 7 (10 %) neurological pathologies declined after reduction. There was no significance in total implementation of prehospital reduction between surgeons and anaesthetists. N = 63 (90 %) of all patients received an immobilisation of the shoulder. N = 68 (97 %) of all patients were transported to a hospital. Time to arrival in hospital was in n = 50 (71.4 %) ≤10 min, in n = 17 (24.2 %) ≤20 min and in n = 3 (4.4 %) ≤30 min. CONCLUSION: Implementation of reduction is independent of pathological neurological or vascular findings. Knowledge and skill is enough to perform a reduction quiet effectively in all emergency physicians. No specific technique can be recommended for prehospital use, the importance of being skilled is more important than one method. Early reduction was performed most rapidly in surgeons, but as well in the recommended time by other medical disciplines. On documented timings to admission hospital waiver of reduction is doubt. Therefore, a reduction in the prehospital setting is possible, but not obligatory.

[Acute posterior dislocation of the sternoclavicular joint: Reduction, fixation by endobutton system and alternative procedures]. / Akute dorsale Sternoklavikulargelenkluxation: Reposition, Fixierung mit Faden-Titanplättchen-System und alternative Techniken.

Acute posterior dislocation of the sternoclavicular (SC) joint is rare but can lead to life-threatening vascular injuries of the mediastinum; however, diagnosis is difficult and the injury can be initially overlooked so that surgical treatment is delayed. Although a variety of different treatment modalities have been published, the ideal fixation technique has not yet been identified. We report the case of a patient suffering from a locked posterior SC joint dislocation caused by a skiing accident. The injury was treated by transarticular endobutton fixation. This article describes the technique and highlights its advantages and disadvantages in comparison to previously published treatment options.

[Osteological interdisciplinary management : exemplified by a bilateral proximal humeral fracture]. / Osteologisch-interdisziplinäres Management : Am Beispiel einer bilateralen proximalen Humerusfraktur.

Following locking plate osteosynthesis of a proximal humeral fracture, a 62-year-old male patient suffered mild secondary dislocation. Subsequent bone densitometry identified an osteoporosis. Laboratory testing and sonography revealed an underlying primary hyperparathyroidism. In the short term, the patient suffered a similar proximal humeral fracture of the contralateral side. Given the knowledge about the underlying osteoporosis a cement-augmented locking plate osteosynthesis was carried out to treat the fracture. Parathyroidectomy was performed shortly thereafter and laboratory parameters returned to normal. Secondary fractures did not arise. Treatment of this patient in a certified osteoporosis center with a multimodal management led to systematic interdisciplinary diagnostics, a specific surgical therapy and ended in an excellent result.

[Anatomy of the acromioclavicular and coracoclavicular region. Functional and clinical aspects]. / Anatomie der akromiokorakoklavikulären Region. Funktionell-klinische Aspekte.

BACKGROUND: The acromioclavicular (AC) joint connects the acromion with the lateral end of the clavicle and constitutes an important load-transmitting element between the upper extremity and the skeleton of the trunk. AIM: This review discusses functional aspects that relate the AC and the coracoclavicular (CC) ligaments to AC joint instability and lateral clavicle fracture. RESULTS: In terms of stability the AC and CC ligaments play a pivotal role for this region. Under normal conditions the restraint system is balanced and becomes unbalanced in cases of injury such as AC joint instability or lateral clavicular fractures. Skeletal injuries frequently affect the ligaments with their usually sharp-angled insertion sites, which alters the function of the restraint system. As a consequence these injuries lead to multidirectional dislocating forces acting on the scapula in relationship to the lateral end of the clavicle. Previously, special attention was given to the vertical dislocation of the lateral clavicle, whereas less attention was paid to other factors which could lead to dislocation in other directions. Therefore, in this review emphasis is placed on the anatomical principles of multidirectional dislocation of the AC joint the fractured lateral clavicle. CONCLUSION: Current clinical classification schemes fail to sufficiently include these multidirectional dislocating forces; however, they have to be considered when choosing the appropriate treatment modality. Thus, understanding the anatomical and functional context of the AC/CC region is essential for a sound management of AC joint injuries and fractures of the distal clavicle.

[Therapy of acute acromioclavicular joint instability. Meta-analysis of arthroscopic/minimally invasive versus open procedures]. / Therapie der akuten AC-Gelenk-Instabilität. Eine Metaanalyse arthroskopischer/minimal-invasiver vs. offener Verfahren.

BACKGROUND: A variety of surgical procedure are desrcibed for the treatment of acute acromioclavicular (AC-) joint injuries. Beside open techniques arthroscopic assisted procedures spread widely. Each surgical technique offers advantages and disadvantages, but none is currently accepted as a gold standard. Therefore, the study aims to review the evidence for arthroscopic and open surgical procedures in the treatment of acute AC joint instabilities. MATERIAL AND METHODS: According to the Cochrane Handbook for Systematic Reviews of Interventions we conducted a defined search of Medline and Embase database for articles publisher over the last ten years. RESULTS: The search resulted in 961 studies of which 32 were included in this review and 3 studies were suitable for a meta-analysis. The functional outcome (Constant score) showed a tendency towards better results after arthroscopic procedures (weighted mean difference 5.60, 95% confidence interval 0.36-10.64). There were no significant differences with respect to complication rates, secondary dislocation in the vertical plane, revision surgery and AC joint instability. CONCLUSION: There is insufficient evidence to inform the surgical management of acute AC joint instability. Due to inconsistent study designs there is no evidence for a general superiority of any of the open or arthroscopic procedures. Randomized, controlled studies are necessary to demonstrate whether arthroscopic techniques show a potential benefit in terms of a better functional outcome.

[Combined ac joint dislocation and distal clavicle fracture. Closed reduction and arthroscopically assisted coracoclavicular fixation]. / Kombinierte AC-Gelenk-Luxation und laterale Klavikulafraktur. Geschlossene Reposition und arthroskopisch gestützte korakoklavikuläre Fixierung.

BACKGROUND: A 55-year-old male patient sustained a dislocation of the acromioclavicular (AC) joint in combination with a distal clavicle fracture. METHODS: Following closed reduction of the fractured clavicle, arthroscopically assisted coracoclavicular fixation was performed. DISCUSSION AND CONCLUSION: A combined injury of a complete ac joint dislocation and a distal clavicle fracture is rare and is not included in currently available classification systems; therefore, in this article a classification and assessment of the stability of this injury as well as appropriate treatment options are discussed.

[Reverse shoulder arthroplasty for primary fracture treatment. Displaced three and four part fractures of the proximal humerus in the elderly patient]. / Die primäre inverse Frakturprothese. Behandlung dislozierter 3- und 4-Fragment-Frakturen des proximalen Humerus beim älteren Patienten.

The treatment of comminuted three and four part fractures of the proximal humerus in elderly patients with degenerative rotator cuff tears is challenging. Primary reverse total shoulder arthroplasty (RSA) is an alternative; however, functional outcome is still unclear due to a lack of study results. The aim of this study was to examine the functional results of RSA and to compare them with the results after reconstruction and locking plate osteosynthesis 1 year after surgery.In this study 24 patients (mean age: 77.9±9.1 years) underwent RSA as primary treatment for three and four part fractures of the proximal humerus with either head split or rotator cuff tears >Bateman type II. The results obtained at 3, 6 and 12 months follow-up included shoulder range of motion (ROM), Constant score, age-adjusted and gender-adjusted Constant score and as a percentage when compared to the uninjured side. Data were compared to patients of matching age, gender and fracture pattern from a prospectively collected database of 526 patients treated by locking plate osteosynthesis.The mean shoulder ROM 1 year after surgery was 105±29° flexion, 99±31° abduction, 22±23° external rotation and 65±26° internal rotation. In 6 patients flexion-abduction was >130°. The mean Constant score (CS) 1 year postoperatively was 62.4±14, age and gender normalized CS was 79.2±20.5, CS compared to the uninjured side was 76.1% and there were no significant differences to matched individuals treated by open reduction and internal fixation using locking plates (p=0.360). There were no infections, dislocations, vascular or neural disorders and surgical revision was not necessary in any patient. RSA should be considered as an appropriate alternative for the primary treatment of comminuted three and four part fractures of the proximal humerus with head split or large rotator cuff tears in elderly patients. Although RSA can provide immediate shoulder stability for elderly patients with severe shoulder injuries, primary RSA needs investigation with regards to long-term outcome.

Attachment sites of the coracoclavicular ligaments are characterized by fibrocartilage differentiation: a study on human cadaveric tissue.

We analyzed the immunohistochemical labeling patterns of the extracellular matrix of the coracoclavicular ligaments (CCL) in order to relate the molecular composition of the attachment sites to their mechanical environment. Ligaments were exposed from 12 fresh-frozen human cadaveric samples (four males, mean age: 48.6 ± 12.1 years). Cryosection of methanol-fixed and decalcified tissue was cut and sections were labeled with a panel of monoclonal antibodies directed against collagens, proteoglycans and proteins of vascular components. Attachment sites of both ligaments showed characteristic fibrocartilaginous labeling of collagen type II, aggrecan and link protein in all samples. Labeling for type II collagen was most conspicuous at the insertion of the coracoid process. Morphometry of adjacent samples revealed a fibrocartilage zone of 10-15% in relationship with the ligament proper, where labeling for type II collagen, aggrecan and link protein was negative. The presence of fibrocartilage at both entheses of the trapezoid and conoid ligament suggests that the CCL complex is subject to shear/compression forces. A variable fibrocartilage differentiation at the entheses of both ligaments may be related to the marked change in loading and insertion angle that the ligaments undergo during shoulder movement.