title: Short to mid-term results of stemless reverse shoulder arthroplasty in a selected patient population compared to a matched control group with stem.
abstract: Little scientific evidence on the clinical and radiological outcome after stemless reverse shoulder arthroplasty (RSA) exists. The hypothesis of this study was that stemless RSA has an inferior outcome compared to RSA with stem.
  
  
  
  All cases of cuff-arthropathy fullfilling strict selection criteria (selection rate 18.4 %) were treated with stemless RSA between 2009 and 2013. Twenty nine of 37 cases (78.4 %) were clinically and radiologically examined by an independent observer. Twenty four of the 29 cases could be matched with 24 patients that underwent conventional stemmed RSA at a different institution based on the following criteria: indication (cuff-arthropathy), age (within 5 years), gender, and time of follow-up (within 2 years). Clincial and radiological outcomes of both groups were compared.
  
  
  
  After mean follow-up of 35 months (range 24-75) no significant difference regarding constant score, ASES, subjective shoulder value, pain score, patient satisfaction, strength, and range of motion was detected. One case of traumatic dislocation was observed in the stemless RSA group. Scapular notching grade 1 was detected in two cases of the stemless group while in the stemmed group five cases with grade 1 and four cases with grade 2 notching were observed. Average post-operative humeral component inclination (neck-shaft angle) in the stemless RSA group (134.4°) was significantly steeper than in the stemmed RSA group (155°) (p < 0.001). No loosening of the humeral component was observed in both groups.
  
  
  
  At short to mid-term follow-up, stemless RSA does not feature inferior clinical or radiological outcomes in a strictly selected patient population.
authors.affiliation: Department of Traumatology and Sports Injuries, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria. philipp.moroder@pmu.ac.at.|Center for Musculoskeletal Surgery, Campus Virchow, Charité -Universitaetsmedizin, Augustenburger Platz 1, 13353, Berlin, Germany. philipp.moroder@pmu.ac.at.
authors.forename: Philipp
authors.initials: P
authors.lastname: Moroder
authors.affiliation: Department of Traumatology and Sports Injuries, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria.
authors.forename: Lukas
authors.initials: L
authors.lastname: Ernstbrunner
authors.affiliation: Department of Orthopedic Surgery, Academic Teaching Hospital LKH Stolzalpe, Stolzalpe 38, 8852, Stolzalpe, Austria.
authors.forename: Christine
authors.initials: C
authors.lastname: Zweiger
authors.affiliation: Department of Orthopedic Surgery, Academic Teaching Hospital LKH Stolzalpe, Stolzalpe 38, 8852, Stolzalpe, Austria.
authors.forename: Maximilian
authors.initials: M
authors.lastname: Schatz
authors.affiliation: Department of Orthopedic Surgery Oberndorf, Academic Teaching Hospital of the Paracelsus Medical University, Paracelsusstrasse 37, 5110, Oberndorf, Austria.
authors.forename: Gerd
authors.initials: G
authors.lastname: Seitlinger
authors.affiliation: Departement of Radiology, LKH Judenburg-Knittelfeld, Oberweggasse 18, 8750, Judenburg, Austria.
authors.forename: Robert
authors.initials: R
authors.lastname: Skursky
authors.affiliation: Department of Traumatology and Sports Injuries, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Becker
authors.affiliation: Department of Traumatology and Sports Injuries, Paracelsus Medical University, Muellner Hauptstrasse 48, 5020, Salzburg, Austria.
authors.forename: Herbert
authors.initials: H
authors.lastname: Resch
authors.affiliation: Department of Orthopedic Surgery, Academic Teaching Hospital LKH Stolzalpe, Stolzalpe 38, 8852, Stolzalpe, Austria.
authors.forename: Rolf Michael
authors.initials: RM
authors.lastname: Krifter
mesh_terms: D000368:Aged; D019643:Arthroplasty, Replacement / Q000009:adverse effects / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D000070636:Rotator Cuff Injuries / Q000601:surgery; D012785:Shoulder Joint / Q000601:surgery*; D000072227:Shoulder Prosthesis; D016896:Treatment Outcome
keywords: Inclination; Neck-shaft angle; Notching; RSA; Reverse shoulder arthroplasty; Stemless