Treatment Options for Slipped Capital Femoral Epiphysis
Since early 2000, elective surgical dislocation of the hip joint, as described by Reinhold Ganz, has permitted us to gain a better understanding of intra-articular hip disease, as well as provide a safe and effective reproducible technique in treating the young adult with hip disease. This technique, now practiced worldwide by specialized hip surgeons, has been applied to a variety of pathology and within different stages of the arthritic process for both joint preservation and replacement (ie, resurfacing). Consequently, the risk and complications of this approach have been well documented, with trochanteric non-union being 1% or less and removal of painful internal fixation being the most commonly reported at about 30%.
The clinical outcome of this technique in the skeletally mature patient has been reproducible with no reported cases of osteonecrosis or neck fracture. Consequently, it would only be natural to apply this technique in the treatment of the skeletally immature patients with unstable subcapital femoral epiphysis where the gains of optimizing functional anatomy are critical to minimize the risks of developing significant intra-articular hip damage.
The merits of open reduction and internal fixation using surgical dislocation of the hip joint, which was originally described by Dunn and modified by Ganz, versus a less-invasive technique of in-situ pinning +/- gentle reduction provides an interesting debate from two centers with a long tradition in the treatment of the pediatric hip. It is only through these exchanges that we can refine the indications of evolving surgical techniques and how to best optimize their outcomes.
Viewpoint 1: Simon P. Kelley, MBChB, FRCS (Tr and Orth); M. Lucas Murnaghan, MD, MEd, FRCSC
Slipped Capital Femoral Epiphysis - In-Situ Screw Fixation
Five years ago, a survey of the membership of the Pediatric Orthopaedic Society of North America (POSNA) on the management of unstable slipped capital femoral epiphysis (SCFE) found remarkable agreement on the gold standard treatment of in-situ screw fixation (ISSF).1 Two years later, similar results were identified in a study of British and Dutch pediatric orthopaedic surgeons.2
Uniformity of management is particularly unusual in the specialty of pediatric orthopaedics, where a range of treatment options is often available for the conditions that we treat, resting on a tenuous foundation of scientific evidence. SCFE is one of the most common pediatric orthopaedic conditions that we see not only in teaching centres, but also in every community hospital across Canada. The majority of these patients will not be managed by pediatric orthopaedic specialists with expertise in complex hip surgery.
It is therefore of legitimate concern that controversy once again surrounds the treatment of unstable SCFE with the emergence of surgical hip dislocation and open reduction and internal fixation (ORIF) as an alternative to ISSF.
A review of the literature on the topic of SCFE reveals a wealth of research that is unfortunately limited to mostly Level IV or V studies.2 A variety of treatment strategies have been described, including operative and non-operative management.3-5 ISSF has risen above all other strategies as a reliable and safe procedure with a low complication rate.5,6 Without a formal reduction maneuver, some gentle internal rotation whilst positioning the limb may effect a modest reduction of the SCFE, minimizing the severity of the slip, prior to percutaneous screw fixation.
Figure 1. 13-year-old male with a three-month history of mild left groin pain, suddenly increasing in severity over 24 hours, and inability to weight bear. Managed by gentle internal rotation of the limb while positioning, capsulotomy and in-situ screw fixation with a 7.3 mm fully threaded cannulated screw. Images show preop, immediate postop and three-month follow-up radiographs.
The near-universal adoption of ISSF is likely due to the fact that it relies on equipment and implants being available at most institutions and a surgical technique that is transferable from other common orthopaedic procedures. Within a training program it is easily taught and supervised, while in the community setting it can be performed with minimal surgical assistance.
Advocates of ISSF have continued to modify the technique, improving the procedure to address several technical issues. Modern imaging methods have improved the accuracy of screw placement to minimize the risk of joint penetration and the risk of AVN or chondrolysis.7 The use of two image intensifiers for biplanar fluoroscopy or a 3D CT C-arm are new additions to the radiographic armamentarium to improve procedural accuracy. Previous issues with the internal fixation devices have been reduced with the use of cannulated screw fixation in preference to multiple pins. Complications related to screw removal are likely to be improved with the demonstration that fully threaded screws may offer some advantages to their partially threaded counterparts.8,9 Recent work has brought attention to the increased intra-capsular pressure that exists in cases of unstable SCFE.10 The release of this hematoma through an anterior or lateral approach can decrease the intra-capsular pressure and potentially decrease the risk of avascular necrosis. The improvements of the classic ISSF to a more contemporary version have addressed many key concerns and have improved an already successful treatment strategy.
Orthopaedic surgeons should not feel that they are offering substandard treatment by way of ISSF. There is very little, if any, evidence to justify the benefits of the alternative experimental procedure of surgical hip dislocation and ORIF over the established gold standard. Surgical hip dislocation is a technically challenging procedure with potentially devastating complications and limited options for salvage. Though there is intuitive benefit to an anatomic reduction to prevent the sequelae of femoroacetabular impingement, the outcomes of the technique are as yet unproven.
There will almost certainly be a place for more complex reconstructive procedures of the hip in SCFE, although we firmly believe that any new procedure should be subject to the rigours of scientific scrutiny in the setting of clinical trials. Should surgical hip dislocation and ORIF prove to be at least as efficacious as ISSF for the treatment of unstable SCFE, with an equally low morbidity and complication rate and similar reproducibility, it should then be widely adopted. Until then, the gold standard of treatment of unstable SCFE should remain as contemporary ISSF.
Reprinted with permission from the Winter 2010 issue of COA Bulletin
- Mooney JF, Sanders JO, Browne RH, Anderson DJ, Jofe M, Feldman D, Raney EM, 2005 Mar-Apr. "Management of unstable/acute slipped capital femoral epiphysis: results of a survey of the POSNA membership." J Pediatr Orthop 25 (2): 162-6
- Witbreuk M, Besselaar P, Eastwood D, 2007. "Current practice in the management of acute/unstable slipped capital femoral epiphyses in the United Kingdom and the Netherlands: results of a survey of the membership of the British Society of Children's Orthopaedic Surgery and the Werkgroep Kinder Orthopaedie." J Pediatr Orthop B 16 (2): 79-83
- Ward WT, Stefko J, Wood KB, Stanitski CL, 1992. "Fixation with a single screw for slipped capital femoral epiphysis." J Bone Joint Surg Am 74 (6): 799-809
- Aronson DD, Carlson WE, 1992. "Slipped capital femoral epiphysis. A prospective study of fixation with a single screw." J Bone Joint Surg Am 74 (6): 810-9
- Aronson DD, Peterson DA, Miller DV, 1992. "Slipped capital femoral epiphysis. The case for internal fixation in situ." Clin Orthop Relat Res (281): 115-22
- Carney BT, Weinstein SL, Noble J, 1991. "Long-term follow-up of slipped capital femoral epiphysis." J Bone Joint Surg Am 73 (5): 667-74
- Westberry DE, Davids JR, Cross A, Tanner SL, Blackhurst DW, 2008 Jan-Feb. "Simultaneous biplanar fluoroscopy for the surgical treatment of slipped capital femoral epiphysis." J Pediatr Orthop 28 (1): 43-8
- Raney EM, Freccero DM, Dolan LA, Lighter DE, Fillman RR, Chambers HG, 2008 Oct-Nov. "Evidence-based analysis of removal of orthopaedic implants in the pediatric population." J Pediatr Orthop 28 (7): 701-4
- Miyanji F, Mahar A, Oka R, Pring M, Wenger D, 2008 Jan-Feb. "Biomechanical comparison of fully and partially threaded screws for fixation of slipped capital femoral epiphysis." J Pediatr Orthop 28 (1): 49-52
- Herrera-Soto JA, Duffy MF, Birnbaum MA, Vander Have KL, 2008 Oct-Nov. "Increased intracapsular pressures after unstable slipped capital femoral epiphysis." J Pediatr Orthop 28 (7): 723-8
Viewpoint 2: Young-Jo Kim, MD, PhD
Case for Open Reduction and Fixation of Acute SCFE
Acute unstable slipped capital femoral epiphysis (SCFE) is defined clinically by the inability to walk even with assistive devices.1 This condition behaves like a true femoral neck fracture and is associated with rate of avascular necrosis (AVN) as high as 47%. Often the resulting deformity from the SCFE is severe, and the natural history of SCFE suggests that moderate to severe deformities have a high likelihood of causing premature osteoarthritis.2
Current controversy regarding the management of an unstable SCFE stems from the need to balance the risk of developing AVN (from the inherent injury and/or surgical manipulation) with the benefits of minimizing the deformity. Although this issue remains controversial, more recent data suggest that open reduction of an unstable SCFE may be beneficial compared to in situ pinning.
There is universal agreement that forceful manipulation of any SCFE is contraindicated. However, inadvertent reduction or gentle closed manipulation is thought to not increase the inherent high rate of AVN. Sankar et al3 compared the rates of AVN in 70 unstable SCFE hips treated with closed vs. open reduction and found that the rate of AVN was higher in the closed reduction group (19-26%) compared to the open reduction group (6%). However, they did not have sufficient power to show statistical significance.
Parsch et al4 have demonstrated that in the truly unstable SCFE, evacuation of the hematoma and a gentle open reduction can result in a fairly low rate (4.7%) of AVN. Therefore, it would appear that an open reduction and gentle open manipulation will not increase the rate of AVN and may, in fact, lower the rate of AVN compared to in situ pinning or gentle closed manipulation and pinning.
Leunig et al5,6 have advocated the use of surgical dislocation to perform the subcapital realignment. This may prove to be safe and will allow full correction of the proximal femoral deformity that would otherwise result in early functional limitations and eventual osteoarthritis. The surgical dislocation approach in itself appears to be safe, with almost zero rate of AVN and a low rate of trochanteric delayed union.7
In 40 cases of moderate to severe SCFE reconstruction using the modified Dunn procedure, Ziebarth et al8 showed that this procedure could be performed with reasonably low risk of AVN (0 out of 40) and full restoration of normal anatomy and function. However, it remains to be seen if this technically demanding procedure can be performed in other centres with the same level of safety. The main advantage of the modified Dunn procedure through a safe surgical dislocation approach is the 1) ability to fully correct the deformity, and 2) ability to identify the avascular head (due to stretching of the retinacular vessels) and to surgically restore the blood flow.
Figure 1 illustrates a case of 12-year-old girl with severe unstable SCFE. Modified Dunn osteotomy was performed, and at the time of surgery, the femoral head was initially avascular (Figure 2A). After freeing of the femoral neck periostium, the femoral head blood supply was restored (Figure 2B,C).
Figure 1. Preoperative films (A, B) show severe unstable SCFE in a 12-year-old girl. After modified Dunn procedure (C, D) the proximal femoral anatomy is restored without AVN.
Figure 2. Initially the femoral head was avascular (A). After freeing the retinacular vessels the femoral head blood supply was restored (B, C).
Using any approach, the risk of AVN in an unstable SCFE is unlikely to approach zero. However, accepting a rate of AVN that can range up to nearly 50% when treated using closed methods seems illogical. Open reduction through an anterior arthrotomy does not appear to increase the rate of AVN as compared to closed treatment and may, in fact, decrease the rate of AVN as well the amount of proximal femoral deformity. The modified Dunn procedure has the advantage of allowing full correction of the deformity as well as the ability to identify avascular heads and possibly restore blood flow; however, it is a technically demanding procedure with the risk of iatrogentic AVN.
In summary, for an unstable acute SCFE, at a minimum, anterior open reduction and pinning should be performed, and in experienced hands, a modified Dunn procedure should be considered.
Reprinted with permission from the Winter 2010 issue of COA Bulletin
- Loder RT, Richards BS, Shapiro PS, Reznick LR, Aronson DD, 1993. "Acute slipped capital femoral epiphysis: the importance of physeal stability." J Bone Joint Surg Am 75 (8): 1134-40
- Carney BT, Weinstein SL, 1996. "Natural history of untreated chronic slipped capital femoral epiphysis." Clin Orthop Relat Res (322): 43-7
- Sankar WN, McPartland TG, Millis MB, Kim YJ, 2010. "The unstable slipped capital femoral epiphysis: risk factors for osteonecrosis." J Pediatr Orthop 30 (6): 544-8
- Parsch K, Weller S, Parsch D, 2009 Jan-Feb. "Open reduction and smooth Kirschner wire fixation for unstable slipped capital femoral epiphysis." J Pediatr Orthop 29 (1): 1-8
- Leunig M, Slongo T, Ganz R, 2008. "Subcapital realignment in slipped capital femoral epiphysis: surgical hip dislocation and trimming of the stable trochanter to protect the perfusion of the epiphysis." Instr Course Lect 57: 499-507
- Leunig M, Slongo T, Kleinschmidt M, Ganz R, 2007. "Subcapital correction osteotomy in slipped capital femoral epiphysis by means of surgical hip dislocation." Oper Orthop Traumatol 19 (4): 389-410
- Ganz R, Gill TJ, Gautier E, Ganz K, Krügel N, Berlemann U, 2001. "Surgical dislocation of the adult hip a technique with full access to the femoral head and acetabulum without the risk of avascular necrosis." J Bone Joint Surg Br 83 (8): 1119-24
- Ziebarth K, Zilkens C, Spencer S, Leunig M, Ganz R, Kim YJ, 2009. "Capital realignment for moderate and severe SCFE using a modified Dunn procedure." Clin Orthop Relat Res 467 (3): 704-16