Is the modified Dunn's procedure superior to in situ fixation? A systematic review and meta-analysis of comparative studies for management of moderate and severe slipped capital femoral epiphysis

Tim Cheok; Thomas Smith; Morgan Berman; Matthew Jennings; Kanishka Williams; Pradeep Mathew Poonnoose; Jaideep Rawat; Bruce Foster

doi:10.1177/18632521221078864

Is the modified Dunn's procedure superior to in situ fixation? A systematic review and meta-analysis of comparative studies for management of moderate and severe slipped capital femoral epiphysis

J Child Orthop. 2022 Feb;16(1):27-34. doi: 10.1177/18632521221078864. Epub 2022 Apr 5.

Authors

Tim Cheok¹, Thomas Smith^{1

2}, Morgan Berman¹, Matthew Jennings¹, Kanishka Williams¹, Pradeep Mathew Poonnoose¹, Jaideep Rawat^{1

3

4}, Bruce Foster^{1

3

4}

Affiliations

¹ Department of Trauma and Orthopaedics, Alice Springs Hospital, Alice Springs, NT, Australia.
² College of Medicine and Public Health, Flinders University, Bedford Park, SA, Australia.
³ Department of Orthopaedic Surgery, Flinders Medical Centre, Bedford Park, SA, Australia.
⁴ Department of Orthopaedic Surgery, Women's and Children's Hospital, North Adelaide, SA, Australia.

Abstract

Purpose: The management of moderate and severe slipped capital femoral epiphysis is controversial. While in situ fixation is commonly used, the modified Dunn's procedure is increasingly popular within high-volume centers. We compared the clinical and radiological outcomes, as well as the rates of femoral head avascular necrosis or chondrolysis in patients managed with either modified Dunn's procedure or in situ fixation.

Methods: A systematic search of the PubMed, Embase, The Cochrane Library, Science Direct, and Web of Science was performed in August 2021. Studies comparing outcomes and complications of modified Dunn's procedure versus in situ fixation in patients with moderate or severe slipped capital femoral epiphysis were included.

Results: A total of four studies were included in the final analysis. Modified Dunn's procedure did not result in improved clinical outcomes. However, radiological outcomes as measured using Southwick angles and Alpha angles were significantly improved in the modified Dunn's procedure group, with a mean difference of -14.68 (p < 0.00001) and -34.26 degrees (p < 0.00001), respectively, compared to in situ fixation. There was no difference in the odds of femoral head avascular necrosis or chondrolysis, with odds ratio of 0.99 (p = 0.97).

Conclusion: Within the limits of our study, modified Dunn's procedure did not improve clinical outcomes. There were significantly improved radiological outcomes without higher odds of femoral head avascular necrosis or chondrolysis. Further long-term studies are required to better guide management of moderate and severe slipped capital femoral epiphysis, especially in unstable slips. In the meantime, we recommend that the modified Dunn's procedure, if done, be restricted to high-volume centers with low complication rates.

Level of evidence: Level III-Systematic review of Level III studies.

Prospero registration no: CRD42021279503.

Keywords: Slipped capital femoral epiphysis; in situ fixation; meta-analysis; modified Dunn’s procedure; systematic review; treatment.

Publication types

Review