gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie, 75. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 97. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 52. Tagung des Berufsverbandes der Fachärzte für Orthopädie und Unfallchirurgie

25. - 28.10.2011, Berlin

Comparison of clinical outcomes of reverse total shoulder arthroplasty performed with 36 mm standard, 36 mmm eccentric CoCrMo and 44 mm cross-linked UHMWPE glenospheres – a multicenter study

Meeting Abstract

  • J.D. Agneskirchner - Sportsclinic Germany, Hannover, Germany
  • A. Bischof - Orthopaedie am Rosenberg, Heiden, Switzerland
  • P. Budassi - Istituti Ortopedici, Cremona, Italy
  • A. Castagna - Istituto Humanitas, Milano, Italy
  • C. Domenghini - Ars Medica Clinic, FMH chirurgia ortopedica, Gravesano, Switzerland
  • H.R. Bloch - Ars Medica Clinic, FMH chirurgia ortopedica, Gravesano, Switzerland
  • Multicenter Study Group SMR

Deutscher Kongress für Orthopädie und Unfallchirurgie. 75. Jahrestagung der Deutschen Gesellschaft für Unfallchirurgie, 97. Tagung der Deutschen Gesellschaft für Orthopädie und Orthopädische Chirurgie, 52. Tagung des Berufsverbandes der Fachärzte für Orthopädie. Berlin, 25.-28.10.2011. Düsseldorf: German Medical Science GMS Publishing House; 2011. DocWI13-101

DOI: 10.3205/11dkou025, URN: urn:nbn:de:0183-11dkou0250

Published: October 18, 2011

© 2011 Agneskirchner et al.
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Outline

Text

Questionnaire: Functional outcome of reverse total shoulder arthroplasty has been encouraging in short and mid-term studies, but the procedure is not without complications. Scapular notching and instability are known to be the most common problems in mid-term follow-up results and may have a causal correlation with poorer clinical outcomes. Two new design features, reducing the prosthesis-scapular neck angle (PSNA) with a distal eccentric overhang and the polyethylene debris with the inversion of materials were compared with the traditional concentric glenosphere design in a multicenter study outcome study.

Methods: Between 2004 and 2007, 147 patients (mean age 69.5 years) treated in 5 centers with a reverse shoulder prosthesis were controlled in a retrospective study with a mean follow up of 37.31±17.86 months. 63 patients (Group A) treated with a 36 mm CoCrMo glenosphere, 23 with a 36 mm CoCrMo eccentric (Group B) glenosphere and 61 with the 44 mm X-UHMWPE glenosphere (Group C). Mainly primary diagnosis was cuff tear arthroplasty (Group A: 36%, B: 12%, C: 29%) secondary osteoarthritis (Group A: 3%, B: 13%, C: 16% ) and cuff tears in endoprosthesis (Group A: 3%, B: 1%, C: 5%). 44% of patients intraoperatively showed a concentric glenoid, 40% an eccentric variante of destruction. 16% showed major osteolysis. Patients were followed clinically to evaluate pain, Constant score and ROM and radiographically to detect scapular notching, instability,loosening and mechanical failure.

Results and conclusions: At 12, 24 and over 30 month follow-up, 44 mm glenosphere had significantly less scapular notching than the 36 concentric (p=0.009) and 36 mm eccentric designs(p=0.001). At 12 months, at 24 months patients with a 44 mm or 36 mm eccentric glenosphere had less pain than patients with a 36 mm concentric design. The Constant score (not influenced by pre-op diagnosis) improved from preoperative measurement to all time-points of evaluations for all 3 groups (P< 0.001). The preoperative average Constant score for the 44 mm glenosphere group was significantly lower than in the 36 eccentric and 36 concentric group (p=0,003), they showed an important improvement at the last follow-up compared to the other groups (Group A 42.3, Group B 36.7 and Group C 53.3; p< 0.001). 44 mm glenospheres allowed a higher and stable increase of ROM in comparison to the concentric and eccentric 36 glenospheres. The overall complication rate was 9.5% in Group A, 0% in Group B and 6.5% in Group C. The use of these new design elements in reverse total shoulder arthroplasty shows promising mid-term results. We found significantly higher clinical scores, better outcomes and a lower rate of complications in the 44mm and 36mm eccentrical Groups than in the control 36mm Group. We attribute these results to the decrease of inferior scapular notching in the 36 eccentric and 44m glenospheres and to the inversion of materials in the 44mm glenosphere. Long-term studies are needed to evaluate the survivorship of the implants.