Modified Dunn procedure versus percutaneous pinning in moderate/severe stable slipped capital femoral epiphyses

Abstract

Background: The modified Dunn procedure (MDP) has risen enthusiasm in treating slipped capital femoral epiphyses (SCFE) due to the anatomic reduction and high patients’ satisfaction rates at long-term follow-up. Main aim of this study is to compare clinical and radiographic outcomes of 2 cohorts with moderate to severe stable SCFE treated by MDP and in situ fixation. Methods: Medical records were analysed to collect demographic data, comorbidities and time from slip to surgery. The collected postoperative data were: avascular necrosis (AVN); complications; progression of osteoarthritis and subsequent procedures. Southwick angles (SA), alpha angles and Klein line were measured on the preoperative x-rays, on the immediate postoperative period and at the latest follow-up. Outcomes scores were recorded by the following questionnaires: the Harris Hip Score, the Hip disability and Osteoarthritis Outcome Score, the Merle d’Aubigné and Postel score and the Western Ontario and McMaster Universities Arthritis Index. Kaplan-Meier survivorship curve was calculated. Results: We compared 81 hips treated by MDP with 22 hips treated by in situ pinning (PS) for moderate/severe stable SCFE. No significant differences were found between the 2 groups in terms of age, BMI, comorbidities and preoperative slip angles. At the latest follow-up, postoperative anteroposterior mean slip angles were respectively 6.2 and 19.9° in MDP and PS group ( p = 0.3). Slip angles in frog lateral view were 11° in the MDP group and 39.7° in the PS group ( p = 0.2). MDP group achieved better correction angles on frog leg view (11° vs. 39.7°; p < 0.001). There was no statistically significant difference in the occurrence of AVN among both groups (19.7% MDP group vs. 31.8% PS group) ( p = 0.2). Conclusions: The MDP in treating severe stable SCFE showed the best deformities corrections in conjunction with the highest functional scores at long-term follow-up and similar rates of osteonecrosis compared to in situ fixation.

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

“…23,27 The remaining two studies did not show any improvement in clinical outcomes between groups. 24,26 It should be noted that the largest series in our included studies by Galleta et al showed no improvement in clinical outcomes.…”

“…Four studies were included in the final analysis. [23][24][25][26] These are summarized in Figure 1. All four studies included were retrospective cohort studies, of which only one study enrolled both stable and unstable slips.…”

“…Clinical outcomes were reported using a variety of scales. Two studies utilized the Merle d’Aubigné score: 23 , 24 one study utilized the Heyman and Herndon Classification score 25 and the final study utilized the Non-Arthritic Hip score. 26 Due to high variability, a meta-analysis was not performed to evaluate this outcome.…”

“…Three studies compared postoperative Southwick angles. 24 – 26 There was significant heterogeneity between studies (I 2 = 76%, p = 0.02), and hence a random effects model was utilized. Based on our meta-analysis, there was significant improvement in postoperative Southwick angles favoring the modified Dunn’s procedure group (MD = –14.68, 95% CI = –8.82 to −10.54, p < 0.00001).…”

“…29 In the three studies where symptoms of FAI were documented, symptomatic FAI occurred in approximately 40% of patients managed with in situ pinning, where 9/18 hips in the Arora et 23,25,26 Although not quantified in the study by Galletta et al, it was recognized that most inferior outcomes in the in situ fixation group were due to hip pain during sports and a positive anterior impingement test. 24 However, it must be recognized that previous long-term studies have shown considerable remodeling of this deformity. [30][31][32] Given the relatively short follow-up period in our included studies, ranging from 4 to 10 years, it is unclear how many of these patients were affected by FAI or osteoarthritis following skeletal maturity.…”