gms | German Medical Science

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2018)

23.10. - 26.10.2018, Berlin

Severe SCFE patients treated with a modified dunn procedure have high survivorship and little Osteoarthritis at long-term follow-up

Meeting Abstract

  • presenting/speaker Till Lerch - Inselspital, Universitätsklinik für Orthopädie, Bern, Switzerland
  • Simon Steppacher - Inselspital, Universitätsklinik für Orthopädie, Bern, Switzerland
  • Florian Schmaranzer - Inselspital, Universitätsklinik für Orthopädie, Bern, Switzerland
  • Moritz Tannast - Inselspital, Universitätsklinik für Orthopädie, Bern, Switzerland
  • Kai Ziebarth - Inselspital Universitätsspital Bern, Abteilung für Kinderorthopädie und Kindertraumatologie, Klinik für Kinderchirurgie, Bern, Switzerland
  • Klaus Siebenrock - Inselspital, Universitätsklinik für Orthopädie, Bern, Switzerland

Deutscher Kongress für Orthopädie und Unfallchirurgie (DKOU 2018). Berlin, 23.-26.10.2018. Düsseldorf: German Medical Science GMS Publishing House; 2018. DocPT18-383

doi: 10.3205/18dkou676, urn:nbn:de:0183-18dkou6769

Veröffentlicht: 6. November 2018

© 2018 Lerch et al.
Dieser Artikel ist ein Open-Access-Artikel und steht unter den Lizenzbedingungen der Creative Commons Attribution 4.0 License (Namensnennung). Lizenz-Angaben siehe http://creativecommons.org/licenses/by/4.0/.


Gliederung

Text

Objectives: The modified Dunn procedure has the potential to restore the anatomy in hips with severe slipped capital femoral epiphyses (SCFE) while protecting the blood supply to the femoral head and minimizing secondary impingement deformities. However, there is controversy about the risks associated with the procedure and mid- to long-term data on clinical outcomes, reoperations, and complications are rare.

Therefore, we report on (1) hip pain and function, (2) the cumulative survivorship with endpoints AVN, OA progression, THA or hip arthrodesis, (3) radiographic anatomy of the proximal femur at follow-up in patients treated with a modified Dunn procedure for severe SCFE (slip angle >60°).

Methods:

We performed a retrospective analysis involving 46 hips of 46 patients treated with a modified Dunn procedure for severe SCFE (slip angle >60°) between 1999 and 2016.

Of the 46 patients, 44 were available for follow-up (mean 8 years, range 1-17). Two patients were lost to follow-up after the 1-year follow-up. We evaluated the clinical and radiographic outcome of 44 hips.

The mean age was 13 years (range 9-19 years). Fourteen out of 46 hips (30%) presented with unstable slips. Mean preoperative slip angle was 64° (range 60-90).

Pain and function were measured using the Merle d'Aubigné and Postel score, PROMs, and the presence of a positive anterior impingement test or Drehmann sign. Cumulative survivorship was calculated according to the method of Kaplan-Meier with three defined endpoints: (1) AVN (2) progression by at least one grade of OA according to Tönnis; (3) subsequent Hip arthrodesis or THA. Radiographic anatomy of the proximal femur was evaluated using the slip angle, alpha angle, Klein line and joint space width.

Results: (1) Mean Merle d'Aubigné and Postel score was 17 points (range 14-18), mean Harris Hip score (HHS) was 93 points (66-100), mean Hip Disability and Osteoarthritis Outcome Score (HOOS) was 90 points (67-100), 28% had a positive anterior impingement test and no hip (0%) had a positive Drehmann sign of the preserved hips at follow-up.

(2) Cumulative survivorship was 93% at 10-year follow-up. Three hips reached at least one of the three endpoints. Two hips (4%) had AVN, one of them underwent hip arthrodesis. One hip had OA progression by at least one grade of OA.

(3) Postoperative slip angle was 7° (1-16). Alpha angle on axial radiograph was 39° (26-71), alpha angle on AP radiograph was 52° (28-95), Klein line was positive in 0%, minimal joint space width was 3 mm (2-5) of the preserved hips at follow-up. 41/44 hips (93%) had no OA (Tönnis 0).

Conclusions: The modified Dunn procedure for severe SCFE largely corrected slip deformities with low risk of progression to AVN, OA, THA or hip arthrodesis and high hip scores at longterm follow-up. However, AVN occurred in 2 hips (4%) and secondary impingement deformities persisted in some hips and of those some underwent further surgical corrections.