Public Defence: Alexander Nilsskog Fraser

Cand. med. Alexander Nilsskog Fraser at Institute of Clinical Medicine will be defending the thesis “Reverse total shoulder arthroplasty in the operative treatment of displaced proximal humeral fractures” for the degree of PhD (Philosophiae Doctor).

Photo: Øystein Horgmo, UiO.

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Due to copyright issues, an electronic copy of the thesis must be ordered from the faculty. For the faculty to have time to process the order, the order must be received by the faculty at the latest 2 days before the public defence. Orders received later than 2 days before the defence will not be processed. After the public defence, please address any inquiries regarding the thesis to the candidate.

Trial Lecture – time and place

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Adjudication committee

  • First opponent: Consultant Orthopaedic and Trauma Surgeon Simon Lambert, University College London Hospital, UK
  • Second opponent: Orthopaedic Surgeon/Ass. Professor Theis Muncholm Thillemann, Aarhus Universitetshospital, Denmark
  • Third member and chair of the evaluation committee: Professor Inger Holm, Faculty of Medicine, University of Oslo

Chair of the Defence

Professor II Anne Eskild, University of Oslo

Principal Supervisor

Senior consultant Tore Fjalestad, Oslo University Hospital

Summary

Proximal humeral fractures (PHF) are among the most common fractures, the incidence increases with age, and are more frequent in women. Most PHFs are minimally displaced and should be treated non-operatively. Approximately 20% of PHFs are severely displaced and may be considered for surgery, but the choice of operative method is controversial.

Osteosynthesis with a locking plate has been the primary operative option. However, studies show high complication rates and around 30% secondary surgeries. The use of reverse total shoulder arthroplasty (RTSA) for displaced PHFs in the elderly has increased. Several studies show results in favor of RTSA, but there is sparse high-level evidence to support this change of operative practice.

The aim of the thesis was to conduct a high-level study of RTSA in the operative treatment of severely displaced 3- and 4-part PHFs in patients aged 65 to 85 years: a randomized controlled trial comparing RTSA with plate fixation. Due to numerous reports stating concern about the stability of the glenoid component of RTSA, we aimed to investigate the stability of the implant using radiostereometric analysis (RSA). An RSA methodology study was conducted, followed by a clinical RSA study on patients with RTSA.

124 patients were included, 90% were women, and 104 patients completed the 2-year follow-up. RTSA scored significantly better than plate fixation in patient reported outcome measures and clinical testing at two years. Regarding implant stability, the precision of model-based RSA on the glenoid component was high and comparable to RSA precision in other implants. Minimal implant migration was detected for the glenoid component in patients at two years using model-based RSA.

Two-year results show a significant clinical difference in favor of RTSA over plate fixation in the treatment severely displaced PHFs in elderly patients. The glenoid component of RTSA was stable measured with RSA at two years, which may indicate long-term stability.

Additional information

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Published May 9, 2023 12:02 PM - Last modified May 23, 2023 1:26 PM