Calcific tendinitis (CT) is a condition that most commonly affects the rotator cuff tendons of the shoulder joint. Fundamental crystal morphology and composition underlying different radiological stages of CT remained insufficiently characterized. We collected human tendon samples from 33 patients with CT and 12 control patients. CT patients exhibited an increased incidence of comorbidities, especially high blood pressure and disorders of fat metabolism. Based on the Gärtner classification, calcific deposits were classified as type I in two patients, type II in 14 patients, and type III in 17 patients. Tendon calcification of the controls was significantly lower compared to the CT group. No differences in the amount of histological calcification between the Gärtner groups were observed. A correlation between the radiological size of calcification and the amount of calcification detected in histology was found. SEM-EDS and Raman identified basic calcium phosphate to be the predominant crystal type in tendons from CT patients, with only two calcium pyrophosphate detections. CT is mainly associated with BCP deposition. Calcified depot size was associated with pain intensity, while diabetes mellitus was observed more frequently in CT patients than in controls. BCP may be a focus of future mechanistic studies on CT.

Background: This study evaluated the short-term clinical and radiological outcomes of an uncemented isoelastic monoblock glenoid component in stemless anatomic total shoulder arthroplasty (aTSA). We hypothesized that the implant's design and biomechanical properties would offer sufficient fixation and good functional outcomes. Methods: In this prospective multicenter study, 75 patients received stemless aTSA for shoulder osteoarthritis using the Affinis Glenoid vitamys implant. We evaluated 64 patients at a mean follow-up of 25.2 ± 2.1 months. The Constant Score, Simple Shoulder Test, active range of motion, and complications were recorded. The radiological evaluation was based on the occurrence of radiolucent lines (RLLs) and periprosthetic bone adaptations using plain radiographs and scored according to Lazarus and Molé. Results: Clinical scores and range of motion outcomes improved significantly after surgery (P < .001). The radiological evaluation revealed minor humeral periprosthetic bone adaptations without clinical consequences. RLLs on the glenoid side were detected in 31.5% of cases; most (62%) of them were < 2 mm. The mean adapted Molé score was 1.08 ± 2.34. Since the majority of observed RLLs were not located around the pegs, 95% of the investigated implants were classified 0 according to Lazarus. Finally, no revision surgery was necessary due to failed fixation or loosening of the glenoid component. Conclusion: Stemless aTSA with the uncemented isoelastic monoblock Affinis Glenoid vitamys yielded good and reliable short-term radiological and clinical results. Studies with a longer follow-up period are necessary to confirm these results.

BACKGROUND:Massive rotator cuff tears (MRCT) are one of the major challenges in reconstructive shoulder surgery and the therapeutic concepts are still controversial. Using conventional reconstruction techniques rotator cuff re-tear rates still occur up to 52%-94% according to the recent literature. Therefore, superior capsule reconstruction (SCR) using acellular human dermal allografts (AHDG) are currently a frequently applied alternative treatment option for MRCT. Although the functional outcome improves, there is some discrepancy in survival time of the graft. The purpose of this study was to evaluate the structural graft integrity by magnetic resonance imaging (MRI) scans and the functional status of the shoulder early after surgery. MATERIALS AND METHODS:Twenty-nine patients with conventionally irreparable MRCT were treated with an arthroscopic SCR utilized an AHDG (Epiflex, DIZG). Pre- and postoperative MRIs were used to evaluate the rotator cuff and graft configuration. The mean MRI follow-up was 9.8 ± 3.9 (6-21) weeks. The functional status was recorded regarding the Constant Score (CS) and active range of motion. General complications were noted. The clinical follow-up (FU) was 9.4 ± 2.9 (6-17) weeks and 1 year postoperatively at 42.5 ± 5.7 (36-58) weeks. RESULTS:The presence of a total graft failure rate of 59% type 3 according to Mirzayan after SCR with AHDG did not negatively influence the functional outcome during the observation period. There was the main effect of time on all directions of range of motion and all categories of the CS-Score (pain: P < .001, activity: P = .01 and motion: P = .04) except for CS-force value (P = .28) at the first FU and the improvement remained constant until the last FU. There were no significant differences in clinical outcome between the group with graft failure and the group with intact graft at the first and last FU. CONCLUSIONS:The SCR with AHDG in MRCT shows high rate of structural graft failures in early postoperative MRI. However, this does not correlate with the functional outcome in early and mid-term FU. Further studies focusing to elucidate the underlying complex process of in vivo AHDG regeneration and recent developments of biological graft healing and surgery techniques may improve the structural integrity of the SCR construct.

Background: The purpose of this study was to evaluate the influence of humeral position of the Affinis Short implant in stemless anatomic total shoulder arthroplasties (STSAs) on clinical and radiologic results and mid- to long-term survival in the treatment of primary osteoarthritis (OA) of the shoulder. Methods: Eighty patients treated with a stemless shoulder arthroplasty for OA of the shoulder were evaluated with a mean follow-up of 92 +/- 14 months (range 69-116 months) by the Constant Score (CS), Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH), and active range of motion (ROM). Radiographic assessment for bone adaptations and humeral implant position was performed by plain radiographs. Comparison of the pre- and postoperative centers of rotation (CORs) was used to assess the restoration of the geometry of the humeral head. The appraisal of proper humeral component positioning was correlated with the functional outcomes. A Kaplan-Meier analysis was performed to investigate the influence of humeral implant position compared to survival time. Complications were noted. Results: The ROM (P < .001), CS (P < .001), and DASH scores (P < .001) showed significant improvements after surgery for the entire series. The COR restoration was anatomic in 75% (n = 60) of all implants and in 25% (n = 20) nonanatomic implants (pre- and postoperative COR deviation of 2.7 +/- 1.8 mm vs. 5.1 +/- 3.2 mm, P = .0380). The humeral component position did not affect the functional outcome whereas the 10-year unadjusted cumulative survival rate for the anatomic group was significantly higher in comparison with the nonanatomic group (96.7% vs. 75%, P = .002). The radiologic evaluation revealed minor periprosthetic bone adaptions in various forms without clinical significance or further intervention. No revision was necessary because of a failed fixation of the stemless humeral component. Conclusions: Regarding the treatment of primary OA of the shoulder, STSA shows excellent long-term survival and clinical outcomes. In particular, STSA implants are able to restore the geometry of the humeral head. Nonanatomic reconstruction may influence the survival over the long term in different pathways. Further studies are necessary to elucidate the effect of humeral component position in STSA on function, pain, and implant survival rates.

Modern shoulder arthroplasties with stemless implants help to preserve the original bone substance of the proximal humerus and to reduce potential risks of conventional implants. Their shape allows newly formed bone to grow directly through the implant. However, it is not fully explained how an optimal fixation of the implant by formation of new bone can be achieved or stimulated. In this context, we develop a method to simulate the mechanical loading of the proximal humerus during the surgery using the finite element method to investigate whether one or more mechanical stress variables can be correlated with measurement data of cell activity in the bone, which is available in the form of SPECT/CT data. This contribution presents measurements with n = 12 $n=12$ explanted humeral heads from patients undergoing planned total shoulder arthroplasties in order to parameterize a material model for trabecular bone to be used in the finite element simulation. The raw data of these measurements were published and can be accessed for further investigations.

Background Shoulder impingement syndrome (SIS) is one of the most common diseases of the shoulder and can be addressed with various therapeutic concepts. Orthobiological agents such as platelet rich plasma with a low side effect rate gain importance in the conservative treatment of SIS. Currently, the knowledge about success rate influencing factors, such as the growth factors (GF) concentration or acromion type, is limited. The aim of this study was to analyze the clinical outcome in the therapy of external SIS using autologous conditioned plasma combined with recombinant human collagen scaffold (ACP/STR) injection in comparison with a corticosteroid-local anesthetic (CSA) injection. Additionally, the influence of potential limiting factors such as GF concentration, age and acromial morphology was proved. Materials and methods This prospective pseudo-randomized trial recruited 58 patients with external SIS who received an ultrasound-guided subacromial injection either an ACP/STR or a CSA followed by physical therapy. Follow-up (FU) was performed at 6 weeks, 3 and 6 months. The outcome was assessed with Constant–Murley score, disability of arm, shoulder and hand score and simple shoulder test. The concentration of GF was measured using ELISA. Results During the FU, the improvement of outcome measures was observed with no differences between both groups. Shoulder force was significantly increased in the ACP/STR group ( p < 0.01). We found no correlation between the amount of GF and age or gender in the ACP/STR patients. An acromion Bigliani type III predisposes for therapy failure ( p < 0.001, OR = 56) in both treatment groups. Conclusions Patients with SIS benefit regarding to PROMs after both ACP/STR and CSA injection and physical therapy. Patients who received ACP/STR obtained superior improvement in force. The quantity of GF did not vary depending on the age, so that ACP/STR can be a treatment option for SIS in elderly patients with multimorbidity. The presence of an acromion type III seems to be a predictive factor for limited effectivity of injections in the clinical management of SIS.

Introduction: Total knee arthroplasty (TKA) bears a potential of rendering patients unsatisfied with the operation as a result of negative affectivity related to osteoarthritis and TKA. Not only is pain a lateralized experience, but negative affect and other psychosomatic correlates of pain might also be processed on grounds of lateralization. Lateralization in this context is likely linked to the amygdalae, which display differential left/right patterns of association with psychopathology. What is noteworthy is that osteoarthritis itself is linked not only to negative effects but also to childhood abuse. Method: The present study tests lateralization of psychosomatic correlates of knee-pain using the brief symptom inventory-18 (BSI-18), the dissociative experiences scale (FDS-20), the pain catastrophizing scale (PCS), the Tampa scale of kinesiophobia (TSK), the childhood trauma screener (CTS) and WOMAC. More precisely, we were interested in predicting the side of operations by means of the above-mentioned constructs using binary logistic regression, based on 150 participants (78 left knees) awaiting TKA for knee-osteoarthritis. Results: Somatization (p = 0.003), childhood abuse (p = 0.04) and pain-catastrophizing (p = 0.04) predicted operations on the right side. Anxiety (p = 0.001) and kinesiophobia (p = 0.002) predicted operations on the left side. Conclusions: Knee-pain may be differentially modulated by its psychosomatic correlates as a result of lateralization and corresponding patterns of psychosomatic reagibility.

PURPOSE:Osteoarthritis (OA) is one of the most common musculoskeletal disorders in the aging population. The correlation of radiographic OA severity, disability and pain is variable and inconsistent for the different joints. This study aims to elucidate the relationship between histological and radiological signs of shoulder OA with pain sensation and functional impairment to potentially adapt the recommendation for surgical treatment for primary total shoulder arthroplasty (TSA).METHODS:Forty-four patients with shoulder OA undergoing TSA using an anatomic stemless implant were included in this study. The radiological OA severity was scored pre-operatively on true ap X-rays according to the Kellgren-Lawrence score (KL-Score). Acromial types according to Bigliani were defined by pre-operative radiological images. The histological OA severity was determined according to the OARSI-Score using bone-cartilage sections from loaded areas of the humeral head. Pain was quantified using the visual analog scale (VAS). The functional status was assessed by the items "mobility" and "strength" out of the Constant-Murley score (CS Score). Demographic data including BMI, age, gender, diabetes mellitus and smoking were recorded.RESULTS:There was no correlation between radiographic and histological severity in shoulder OA. However, a correlation of age and the severity of radiological changes was observed. Further, pain did not correlate with histological or radiological scores, whereas it correlated with age and the presence of diabetes mellitus. The functional shoulder status (mobility, strength) correlated with the severity of radiological changes, but not with the histologic scoring, which correlated with nicotine abuse.CONCLUSION:This study shows that increased age is the main determinant of radiological changes in shoulder OA, as well as pain. Therefore, age and pain sensation should be considered as important parameters for the recommendation for TSA.

Introduction: Chronic pain is a multifaceted disorder genuinely entangled with psychic and psychosomatic symptoms, which are typically involved in the processes of chronification. The impingement syndrome of the shoulder is no exception to this rule, but several studies have shown respective peculiarities among those with pain and impingement of the shoulder. Notably, chronic pain is a lateralized experience, and, similarly, its psychosomatic correlates may be attached to the hemispheres functionally. Aim: The present review therefore gives an overview of the respective findings, with regard not only to psychopathology, but also to personality factors and psychologic trauma, since the latter are reportedly associated with chronic pain. Moreover, we acknowledge symmetry as a possible pathogenic factor. Methods: This narrative review followed the current standards for conducting narrative studies. Based on prior findings, our research strategy included the relevance of psychotraumatologic and symmetrical aspects, as well as comorbidity. We retrieved the relevant literature reporting on the impact of psychopathology as well as personality features on shoulder pain, as published up to January 2022 from the Medline database (1966–2022). Study selecton: We included numerous studies, and considered the contextual relevance of studies referring to the neuropsychosomatics of chronic pain. Results: Pain-specific fears, depression, and anxiety are important predictors of shoulder pain, and the latter is generally overrepresented in those with trauma and PTSD. Moreover, associations of shoulder pain with psychological variables are stronger as regards surgical therapies as compared to conservative ones. This may point to a specific and possibly trauma-related vulnerability for perioperative maladaptation. Additionally, functional hemispheric lateralization may explain some of those results given that limb pain is a naturally lateralized experience. Not least, psychosocial risk factors are shared between shoulder pain and its physical comorbidities (e.g., hypertension), and the incapacitated state of the shoulder is a massive threat to the function of the human body as a whole. Conclusions: This review suggests the involvement of psychosomatic and psychotraumatologic factors in shoulder impingement-related chronic pain, but the inconclusiveness and heterogeneity of the literature in the field is possibly suggestive of other determinants such as laterality.

AIMS:The purpose of this study was to compare clinical results, long-term survival, and complication rates of stemless shoulder prosthesis with stemmed anatomical shoulder prostheses for treatment of osteoarthritis and to analyze radiological bone changes around the implants during follow-up.METHODS:A total of 161 patients treated with either a stemmed or a stemless shoulder arthroplasty for primary osteoarthritis of the shoulder were evaluated with a mean follow-up of 118 months (102 to 158). The Constant score (CS), the Disabilities of the Arm, Shoulder and Hand (DASH) score, and active range of motion (ROM) were recorded. Radiological analysis for bone adaptations was performed by plain radiographs. A Kaplan-Meier survivorship analysis was calculated and complications were noted.RESULTS:The ROM (p < 0.001), CS (p < 0.001), and DASH score (p < 0.001) showed significant improvements after shoulder arthroplasty for both implants. There were no differences between the groups treated with stemmed or stemless shoulder prosthesis with respect to the mean CS (79.2 (35 to 118) vs 74.4 (31 to 99); p = 0.519) and DASH scores (11.4 (8 to 29) vs 13.2 (7 to 23); p = 0.210). The ten-year unadjusted cumulative survival rate was 95.3% for the stemmed anatomical shoulder prosthesis and 91.5% for the stemless shoulder prosthesis and did not differ between the treatment groups (p = 0.251). The radiological evaluation of the humeral components in both groups did not show loosening of the humeral implant. The main reason for revision for each type of arthroplasties were complications related to the glenoid.CONCLUSION:The use of anatomical stemless shoulder prosthesis yielded good and reliable results and did not differ from anatomical stemmed shoulder prosthesis over a mean period of ten years. The differences in periprosthetic humeral bone adaptations between both implants have no clinical impact during the follow-up. Cite this article: Bone Joint J 2021;103-B(7):1292-1300.

Anatomical shoulder arthroplasties (ASA) may fail because of micromotion at the modular taper junction causing wear due to fretting. Sufficient taper strength can reduce micromotion and potential reasons for failure. However, there are no normative standards for a safe assembly process performed intraoperatively by the surgeon. The purpose of this study is to determine the effect of common intraoperative assembly strategies and to identify critical influencing factors on taper stability. ASA with standard and stemless humeral component in combination with concentric Al2O3 heads and eccentric CoCr28Mo6 alloyed humeral heads were tested. Taper angles and surface roughness were determined. Force magnitudes and impact directions were recorded using a sensorized head impactor and a three-dimensional force measuring platform. Subsequently, the axial pull-off forces were measured and taper engagement areas were macroscopically evaluated. In comparison to standard stem tapers that were impacted with an assembly device, stemless tapers were impacted into the artificial bone with significantly lower forces. Taper strength correlates to maximum impact force and was higher for CoCr28Mo6 heads with a mean pull-off ratio of 0.56 than for Al2O3 heads with 0.37. Interestingly, all tapers showed an asymmetric clamping behavior, due to tilting during impaction. This is caused by the variation of the resulting force vector and further promoted by humeral head eccentricity. Assembly technique markedly influences the force magnitude, impact direction, impulse, and consequently taper strength. The resulting force vector and head eccentricity were identified as potential risk factors for taper malalignment.

Background: Osteoarthritis (OA) is one of the most common musculoskeletal disorders in the aging population. The correlation of radiographic OA severity, disability and pain is variable and inconsistent for the different joints. This study aims to elucidate the relationship between histological and radiological signs of shoulder OA with pain sensation and functional impairment to potentially adapt the recommendation for surgical treatment for primary total shoulder arthroplasty (TSA). Methods: Forty-four patients with shoulder OA undergoing TSA using an anatomic stemless implant were included in this study. The radiological OA severity was scored preoperatively on true ap X-rays according to the Kellgren-Lawrence-Score (KL-Score). Acromial types according to Bigliani were defined by preoperative radiological images. The histological OA severity was determined according to the OARSI-Score using bone-cartilage sections from loaded areas of the humeral head. Pain was quantified using the Visual Analog Scale (VAS). The functional status was assessed by the items “mobility” and “strength” out of the Constant-Murley-Score (CS-Score). Demographic data including BMI, age, gender, diabetes mellitus and smoking were recorded. Results: There was no correlation between radiographic and histological severity in shoulder OA. However, a correlation of age and the severity of radiological changes was observed. Further, pain did not correlate with histological or radiological scores, whereas it correlated with age and the presence of diabetes mellitus. The functional shoulder status (mobility, strength) correlated with the severity of radiological changes, but not with the histologic scoring, which correlated with nicotine abuse. Conclusion: This study shows that increased age is the main determinant of radiological changes in shoulder OA, as well as pain. Therefore, age and pain sensation should be considered as important parameters for the recommendation for TSA.

Wear and corrosion at taper junctions of orthopaedic endoprostheses remain of great concern and are associated with adverse clinical reactions. Whereas tribocorrosion of hip tapers was extensively investigated, there is only little knowledge regarding the clinical performance of modular total shoulder prostheses. This retrieval study evaluated 35 modular taper junctions of anatomical shoulder explants using stereomicroscopy, confocal microscopy, as well as optical and scanning electron microscopy to determine the damage modes as well as the effects of taper topography and alloy microstructure. Among all humeral head tapers, 89% exhibited material degradation. Different overlapping wear mechanisms were identified such as plastic deformation, adhesive material transfer, microploughing, and fretting damage. Only CoCrMo cast alloy heads showed a susceptibility to electrochemically dominated fretting in comparison to CoCrMo wrought alloy. Moreover, corundum blasted stem tapers show a significantly increased incidence rate for microploughing. To date, this is the most comprehensive study on the damage types of modular taper junctions of anatomical shoulder arthroplasty proving the existence of fretting even on less weight-bearing implants. This study revealed critical fretting factors, such as the surface finish and the alloy type that are essential for the development of countermeasures that avoid any taper corrosion.

Background: Adjustable shoulder hemiarthroplasty (HA) allows the complex anatomy of the proximal humerus, including its centre of rotation, to be restored. However, whether better anatomical adaptation improves clinical outcomes and long-term survival remains unclear. Therefore long-term clinical and radiographic results of an eccentric adjustable hemiprosthesis were examined, focusing on the longevity and fixation of the humeral stem. Hypothesis: Adjustable shoulder HA enhances long-term functional outcomes and reduces complications. Materials and methods: In this prospective multicentre study, 120 HAs were performed using a stemmed hemiprosthesis on 115 patients. The clinical and radiologic outcomes were measured at 3, 6, 12, and 24 months, and thereafter at 4, 7, and 10 years with a median follow-up period of 7.7 years (92.3 months, range 2.6-148.5 months). Revision-free survival rates were calculated up to 10 years postoperatively. Results: The mean Constant-Murley score increased over the first 24 months from 26.2 +/- 9.0 to 61.0 +/- 17.3 points, then levelled off until the final follow-up. Patients with humeral head necrosis had the best clinical outcomes, while patients with fracture sequelae and rheumatoid arthritis had the worst. Although radiolucent lines were more frequent after cemented fixation, lines of >2 mm only occurred after uncemented fixation. Finally, five cases required secondary glenoid implantation, and survival free from stem revision was 99.0% (95% confidence interval [CI], 92.8%-99.9%) at 4 years, 97.6 (95% CI, 90.6%-99.4%) at 7 years, and 92.2% (95% CI, 81.9%-96.8%) at 10 years. Discussion: The study showed that adjustable shoulder HA is a safe and effective treatment option for various degenerative disorders of the shoulder joint. Functional scores first increased, then levelled off after 24 months. Moreover, revision-free survival compared well with previously reported values. Observed stable long-term results confirm that adjustable shoulder HA has beneficial clinical outcomes and a low complication rate. (C) 2018 Published by Elsevier Masson SAS.

Purpose Direct magnetic resonance arthrography (MRA) offers increased diagnostic accuracy compared to conventional magnetic resonance imaging (MRI) in the detection of superior labrum anterior-posterior (SLAP) lesions. The aim of the present study was to present the technique of magnetic resonance-guided direct shoulder arthrography (MDSA), to evaluate the diagnostic value of this novel MRA procedure to detect SLAP lesions in comparison to the currently practiced MRI, and to correlate the radiological findings to the respective arthroscopic findings. Material and methods Fifty-six patients with clinical signs of a SLAP lesion underwent both MRI examination and MDSA prior to arthroscopic surgery. The MRI of both interventions were compared with the arthroscopic findings. Statistical analysis was performed using the McNemar test. Results Sensitivity, specificity, and accuracy for detecting SLAP lesions were 23%, 88%, and 54% on MRI and 80%, 81%, and 80% on MDSA, respectively. Sensitivity (p < 0.001) and accuracy (p = 0.001) in detection of SLAP lesions were significantly higher by MDSA whereas accuracy showed no significant differences (p = 0.625). Conclusions The MDSA can be performed in an open 1.0-T MRI scanner with a high level of technical success and a reasonable methodical effort. The modification of MRA provides the requirements as a practicable routine shoulder magnetic resonance examination including arthrography to detect SLAP lesions. The diagnostic value is significantly better than MRI examinations without included arthrography, which currently predominates the clinical practice to investigate shoulder pathology.

Adjustable shoulder hemiarthroplasty (HA) allows the complex anatomy of the proximal humerus, including its centre of rotation, to be restored. However, whether better anatomical adaptation improves clinical outcomes and long-term survival remains unclear. Therefore long-term clinical and radiographic results of an eccentric adjustable hemiprosthesis were examined, focusing on the longevity and fixation of the humeral stem. Adjustable shoulder HA enhances long-term functional outcomes and reduces complications. In this prospective multicentre study, 120 HAs were performed using a stemmed hemiprosthesis on 115 patients. The clinical and radiologic outcomes were measured at 3, 6, 12, and 24 months, and thereafter at 4, 7, and 10 years with a median follow-up period of 7.7 years (92.3 months, range 2.6–148.5 months). Revision-free survival rates were calculated up to 10 years postoperatively. The mean Constant-Murley score increased over the first 24 months from 26.2 ± 9.0 to 61.0 ± 17.3 points, then levelled off until the final follow-up. Patients with humeral head necrosis had the best clinical outcomes, while patients with fracture sequelae and rheumatoid arthritis had the worst. Although radiolucent lines were more frequent after cemented fixation, lines of > 2 mm only occurred after uncemented fixation. Finally, five cases required secondary glenoid implantation, and survival free from stem revision was 99.0% (95% confidence interval [CI], 92.8%–99.9%) at 4 years, 97.6 (95% CI, 90.6%–99.4%) at 7 years, and 92.2% (95% CI, 81.9%–96.8%) at 10 years. The study showed that adjustable shoulder HA is a safe and effective treatment option for various degenerative disorders of the shoulder joint. Functional scores first increased then levelled off after 24 months. Moreover, revision-free survival compared well with previously reported values. Observed stable long-term results confirm that adjustable shoulder HA has beneficial clinical outcomes and a low complication rate.

Background: The early diagnosis of suspected periprosthetic low-grade infections in shoulder arthroplasties is important for the outcome of the revision surgical procedures. The aim of this study was to investigate new biomarkers of infection in revision shoulder arthroplasties, taking into account the implant design, patient age, and comorbidities. Methods: The study included 33 patients with shoulder arthroplasties undergoing revision surgical procedures. Microbiological diagnostic testing was performed in all cases. C-reactive protein serum levels and white blood cell counts were evaluated, and the periprosthetic tissue was stained immunohistologically for the terminal complement pathway components (C3, C5. and C9) and for CD68 and alpha-defensin. Results: Microbiological diagnostic testing detected a periprosthetic infection in 10 reverse shoulder arthroplasties and in 4 anatomic shoulder arthroplasties. while the remaining 19 shoulder arthroplasties were classified as aseptic. We observed more Staphylococcus epidermidis infections in reverse shoulder arthroplasties and more Staphylococcus aureus infections in anatomic shoulder arthroplasties. The revision rate correlated with pre-existing comorbidities and number of previous surgical procedures. The C-reactive protein values and the incidence of specific periprosthetic radiolucent lines were significantly increased in septic revision cases. We found increased staining for all tested complement factors (C3, C5, and C9) but not for alpha-defensin and CD68 in septic tissue. The most interesting finding was that C9 separated septic from aseptic tissue with a predictive specificity of 100% and a sensitivity of 88.89%. Conclusion: We observed a strong correlation between C9 expressions in septic revision tissue. We propose that the terminal complement pathway. especially C9 deposition, may be a potential biomarker to identify septic complications using tissue biopsy specimens. (C) 2018 Journal of Shoulder and Elbow Surgery Board of Trustees. All rights reserved.

Die Magnetresonanztomographie (MRT) hat sich als Standardverfahren für die bildgebende Diagnostik von Schultergelenkpathologien etabliert. Insbesondere für die Diagnostik von Rotatorenmanschettenrupturen (RMR) steht neben der konventionellen MRT-Untersuchung auch die direkte MR-Arthrographie zur Verfügung. Ziel dieser Studie war es, die Wertigkeit dieser beiden Untersuchungsverfahren in der Diagnostik von Rotatorenmanschettenpartialläsionen (RMPR) zu ermitteln und die Befunde mit dem arthroskopischen Befund zu evaluieren.