@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{SchmalzlGrafKimmeyeretal.2022,
  author    = {Schmalzl, Jonas and Graf, Annika and Kimmeyer, Michael and Gilbert, Fabian and Gerhardt, Christian and Lehmann, Lars-Johannes},
  title     = {Treatment of avascular necrosis of the humeral head - Postoperative results and a proposed modification of the classification},
  series = {BMC Musculoskeletal Disorders},
  volume    = {23},
  journal   = {BMC Musculoskeletal Disorders},
  doi       = {10.1186/s12891-022-05338-1},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-299815},
  year      = {2022},
  abstract  = {Background Avascular necrosis of the humeral head after proximal humeral fracture i.e. type 1 fracture sequelae (FS) according to the Boileau classification is a rare, often painful condition and treatment still remains a challenge. This study evaluates the treatment of FS type 1 with anatomic and reverse shoulder arthroplasty and a new subclassification is proposed. Methods This single-center, retrospective, comparative study, included all consecutive patients with a proximal humeral FS type 1 treated surgically in a four-year period. All patients were classified according to the proposed 3 different subtypes. Constant score (CS), Quick DASH score, subjective shoulder value (SSV) as well as revision and complication rate were analyzed. In the preoperative radiographs the acromio-humeral interval (AHI) and greater tuberosity resorption were examined. Results Of 27 with a FS type 1, 17 patients (63\%) with a mean age of 64 ± 11 years were available for follow-up at 24 ± 10 months. 7 patients were treated with anatomic and 10 with reverse shoulder arthroplasty. CS improved significantly from 16 ± 7 points to 61 ± 19 points (p < 0.0001). At final follow-up the mean Quick DASH Score was 21 ± 21 and the mean SSV was 73 ± 21 points. The mean preoperative AHI was 9 ± 3 mm, however, 8 cases presented an AHI < 7 mm. 4 cases had complete greater tuberosity resorption. The complication and revision rate was 19\%; implant survival was 88\%. Conclusion By using the adequate surgical technique good clinical short-term results with a relatively low complication rate can be achieved in FS type 1. The Boileau classification should be extended for fracture sequelae type 1 and the general recommendation for treatment with hemiarthroplasty or total shoulder arthroplasty has to be relativized. Special attention should be paid to a decreased AHI and/or resorption of the greater tuberosity as indirect signs for dysfunction of the rotator cuff. To facilitate the choice of the adequate prosthetic treatment method the suggested subclassification system should be applied.},
  language  = {en}
}