Strategies to Avoid Osteonecrosis in Unstable Slipped Capital Femoral Epiphysis

Abstract

Osteonecrosis of the femoral epiphysis following slipped capital femoral epiphysis (SCFE) causes substantial patient morbidity.» The etiology of osteonecrosis following SCFE is multifactorial, and multiple treatment strategies, including techniques of epiphyseal reduction, capsulotomy, and timing of surgical intervention, that are intended to reduce this risk have been utilized. » At the present time, because of conflicting data and the lack of high-level evidence, there are a paucity of data to determine the role that these techniques play in reducing the risk of osteonecrosis.» Further scientific research is needed to understand the etiology of osteonecrosis following SCFE. Slipped capital femoral epiphysis (SCFE) is a disorder of the immature proximal femoral physis that can lead to substantial patient morbidity and long-term sequelae. The long-term consequences of SCFE include femoroacetabular impingement secondary to proximal femoral deformity, chondrolysis, slip progression, and osteoarthritis. The most devastating early complication is osteonecrosis of the femoral head that may cause early deterioration of the hip 1 . Because the etiology of osteonecrosis following SCFE is likely multifactorial and remains incompletely understood, a variety of surgical techniques have been utilized to attempt to alter this sequela. Historical treatment options, including spica casting and open physiodesis, were largely abandoned by the 1950s, when the modern technique of in situ pinning was described. Currently, there remains controversy with regard to the timing of intervention, the role of capsulotomy with hematoma evacuation 2 , and closed reduction [2][3][4] . The type of surgical intervention chosen and the surgeon's technique may have a substantial impact on the patient's outcome and likelihood of complications. The treatment paradigm became more complex in 2009 when Ziebarth et al. 5 published the first outcomes of the modified Dunn proximal femoral capital realignment technique utilizing a surgical hip dislocation approach. However, in the current era, recognizing the potential for iatrogenic complications 6 , the indications for this open reduction technique remain a topic of debate, with authors suggesting a role for patients with radiographically severe slips 7 , as well as those with acute, unstable slips 8 .Disclosure: There was no source of external funding for this study. On the Disclosure of Potential Conflicts of Interest forms, which are provided with the online version of the article, one or more of the authors checked "yes" to indicate that the author had a relevant financial relationship in the biomedical arena outside the submitted work (http://links.lww.com/JBJSREV/A439).

Screw Thread Configuration Has No Effect on Outcomes of In Situ Fixation for Stable Slipped Capital Femoral Epiphysis

“…Number of implants also plays a role in fixation stability, with several studies showing modest improvements in stability when using multiple implants, especially for intrinsically less stable severe slips requiring multiple fixation points. [18][19][20][21] However, some authors argue that adding implants increases intraarticular penetration and improper placement, elevating the risk for serious complications (eg, AVN, chondrolysis). 22 While several clinical studies have demonstrated increased risk of AVN with multiple implants, others report similar AVN rates in single-implant and multiple-implant fixation constructs.…”

Slipped capital femoral epiphysis: an epidemiological Nationwide study in Italy from 2001 to 2015

“…However, based on the current literature, the best treatment for stable SCFE is in situ pinning with a single screw, performed regardless of the timing of presentation [ 36 ]. The unstable SCFE is related to a higher risk of osteonecrosis (20–50% of cases) [ 37 – 39 ], but the proper treatment and the timing associated with the lowest risk of AVN are still debated [ 11 , 36 ].. The technique described by Parsch and colleagues (open capsulotomy and partial reduction) seems to be the most promising, reporting a low rate of AVN [ 40 ].…”

“…The technique described by Parsch and colleagues (open capsulotomy and partial reduction) seems to be the most promising, reporting a low rate of AVN [ 40 ]. Moreover, the modified Dunn procedure historically reported satisfactory outcomes with a low rate of necrosis, but it is widely influenced by the surgeon’s technique and skills [ 36 ].…”

“…The most relevant complications of SCFE are AVN; degenerative osteoarthritis; acute loss of cartilages known as chondrolysis (reported after SCFE surgery or in untreated SCFE); femoroacetabular impingement [ 3 , 12 , 41 – 43 ]. The rate of AVN varies in the literature, but it is usually more frequent in unstable SCFE compared to stable forms [ 36 ]. Loder and colleagues [ 9 ] reported an AVN incidence of 0 and 47% for stable and unstable SCFE forms, respectively.…”

Intraoperative assessment of femoral head perfusion during surgical hip dislocation for slipped capital femoral epiphysis

“…The intraoperative assessment of femoral head perfusion is becoming increasingly common when treating SCFEs [ 31 , 32 ]. Many studies have now published results suggesting that this may be a more accurate and easier way to predict the development of AVN rather than previously described methods such as MRI, bone scan or angiography [ 14 , 19 ].…”