@article{SchmalzlFenwickReicheletal.2022,
  author    = {Schmalzl, Jonas and Fenwick, Annabel and Reichel, Thomas and Schmitz, Benedikt and Jordan, Martin and Meffert, Rainer and Plumhoff, Piet and Boehm, Dirk and Gilbert, Fabian},
  title     = {Anterior deltoid muscle tension quantified with shear wave ultrasound elastography correlates with pain level after reverse shoulder arthroplasty},
  series = {European Journal of Orthopaedic Surgery \& Traumatology},
  volume    = {32},
  journal   = {European Journal of Orthopaedic Surgery \& Traumatology},
  number    = {2},
  issn      = {1432-1068},
  doi       = {10.1007/s00590-021-02987-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-268441},
  pages     = {333-339},
  year      = {2022},
  abstract  = {Introduction Reverse shoulder arthroplasty (RSA) leads to medialization and distalization of the centre of rotation of the shoulder joint resulting in lengthening of the deltoid muscle. Shear wave ultrasound elastography (SWE) is a reliable method for quantifying tissue stiffness. The purpose of this study was to analyse if deltoid muscle tension after RSA correlates with the patients' pain level. We hypothesized that higher deltoid muscle tension would be associated with increased pain. Material and methods Eighteen patients treated with RSA were included. Constant score (CS) and pain level on the visual analogue scale (VAS) were analysed and SWE was performed on both shoulders. All three regions of the deltoid muscle were examined in resting position and under standardized isometric loading. Results Average patient age was 76 (range 64-84) years and average follow-up was 15 months (range 4-48). The average CS was 66 points (range 35-89) and the average pain level on the VAS was 1.8 (range 0.5-4.7). SWE revealed statistically significant higher muscle tension in the anterior and middle deltoid muscle region in patients after RSA compared to the contralateral non-operated side. There was a statistically significant correlation between pain level and anterior deltoid muscle tension. Conclusion SWE revealed increased tension in the anterior and middle portion of the deltoid muscle after RSA in a clinical setting. Increased tension of the anterior deltoid muscle portion significantly correlated with an increased pain level. SWE is a powerful, cost-effective, quick, dynamic, non-invasive, and radiation-free imaging technique to evaluate tissue elasticity in the shoulder with a wide range of applications.},
  language  = {en}
}
@article{SchmalzlPlumhoffGilbertetal.2019,
  author    = {Schmalzl, Jonas and Plumhoff, Piet and Gilbert, Fabian and Gohlke, Frank and Konrads, Christian and Brunner, Ulrich and Jakob, Franz and Ebert, Regina and Steinert, Andre F.},
  title     = {Tendon-derived stem cells from the long head of the biceps tendon},
  series = {Bone \& Joint Research},
  volume    = {8},
  journal   = {Bone \& Joint Research},
  number    = {9},
  doi       = {10.1302/2046-3758.89.BJR-2018-0214.R2},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-200370},
  pages     = {414-424},
  year      = {2019},
  abstract  = {Objectives The long head of the biceps (LHB) is often resected in shoulder surgery and could therefore serve as a cell source for tissue engineering approaches in the shoulder. However, whether it represents a suitable cell source for regenerative approaches, both in the inflamed and non-inflamed states, remains unclear. In the present study, inflamed and native human LHBs were comparatively characterized for features of regeneration. Methods In total, 22 resected LHB tendons were classified into inflamed samples (n = 11) and non-inflamed samples (n = 11). Proliferation potential and specific marker gene expression of primary LHB-derived cell cultures were analyzed. Multipotentiality, including osteogenic, adipogenic, chondrogenic, and tenogenic differentiation potential of both groups were compared under respective lineage-specific culture conditions. Results Inflammation does not seem to affect the proliferation rate of the isolated tendon-derived stem cells (TDSCs) and the tenogenic marker gene expression. Cells from both groups showed an equivalent osteogenic, adipogenic, chondrogenic and tenogenic differentiation potential in histology and real-time polymerase chain reaction (RT-PCR) analysis. Conclusion These results suggest that the LHB tendon might be a suitable cell source for regenerative approaches, both in inflamed and non-inflamed states. The LHB with and without tendinitis has been characterized as a novel source of TDSCs, which might facilitate treatment of degeneration and induction of regeneration in shoulder surgery.},
  language  = {en}
}