Sankar, J Bone Joint Surg Am 2013 - The Modified Dunn Procedure for Unstable Slipped Capital Femoral Epiphysis: A Multicenter Perspective - Article Summary

The Modified Dunn Procedure for Unstable Slipped Capital Femoral Epiphysis: A Multicenter Perspective

Sankar, Karlen, et al.·J Bone Joint Surg Am·2013·161 citations·Retrospective cohort

Background

The modified Dunn procedure has rapidly gained popularity as a treatment for unstable slipped capital femoral epiphysis (SCFE), but limited data exist regarding its safety and efficacy. The purpose of this study was to present results and complications following this procedure in a large multicenter series.

Methods

We reviewed the outcomes of all patients who had been treated with the modified Dunn procedure by five surgeons from separate tertiary-care institutions.
All slipped capital femoral epiphyses were defined as unstable according to the Loder criteria.
Patients with less than one year of follow-up and those with an underlying endocrinopathy or syndrome were excluded.
All surgical procedures were performed by pediatric orthopaedic surgeons who had specific training in the modified Dunn procedure.
Operative reports, outpatient records, and follow-up radiographs were used to determine the demographic information, type of fixation, final slip angle, presence of osteonecrosis, and any additional complications.
Standardized surveys were administered to determine the pain level (0 to 10 scale), satisfaction (0 to 100 scale), function (modified Harris hip score, 0 to 91 scale), and activity level (UCLA [University of California Los Angeles] activity score, 0 to 10 scale) at time of the most recent follow-up.

Results

27 patients (27 hips) with a mean of 22.3 months (range, 12 to 48 months) of follow-up met the inclusion criteria.
4 patients (15%) had broken implants at 3 to 18 weeks after surgery and required revision fixation.
7 patients (26%) developed osteonecrosis at a mean of 21.4 weeks (range, 10 to 39 weeks), with each surgeon having at least one case of osteonecrosis.
The mean slip angle at the time of the most recent follow-up was 6° (95% confidence interval, 2° to 11°).
Patients who did not develop osteonecrosis had significantly better clinical results compared with those who developed osteonecrosis, as demonstrated by a lower mean pain score (0.3 compared with 3.1, p = 0.002), higher level of satisfaction (97.1 compared with 65.8, p = 0.001), higher modified Harris hip score (88.0 compared with 60.0, p = 0.001), and higher UCLA activity score (9.3 compared with 5.9, p = 0.031).

Conclusions

This largest reported series of unstable slipped capital femoral epiphyses treated with the modified Dunn procedure demonstrated that the procedure is capable of restoring anatomy and preserving function after a slip but that implant complications and osteonecrosis can and do occur postoperatively.

Level of evidence: Therapeutic Level IV. Copyright remains with the authors and publisher.

Supplemental

The Modified Dunn Procedure for Unstable Slipped Capital Femoral Epiphysis: A Multicenter Perspective.

Sankar, Karlen, et al.J Bone Joint Surg Am2013161 citationsRetrospective cohort