Surgical hip dislocation in treatment of slipped capital femoral epiphysis

Abstract

Background: Most surgeons advocate in situ fixation of the slipped epiphysis with acceptance of any persistent deformity in the proximal femur [Aronsson DD, Loder RT, Breur GJ, Weinstein SL (2006) Slipped capital femoral epiphysis: current concepts. J Am Acad Orthop Surg 14, 666–679]. This residual deformity can lead to osteoarthritis due to femoroacetabular cam impingement (FAI) [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]. Objective: The primary aim of our study was to report the results of the technique of capital realignment with Ganz surgical hip dislocation and its reproducibility to restore hip anatomy and function. Patients and methods: This prospective case series study included 30 patients (32 hips, 13 left (Lt) hips, 19 right (Rt) hips) with stable chronic slipped capital femoral epiphysis (SCFE) after surgical correction with a modified Dunn procedure. This study included 22 males and eight females. The mean age of our patients was 14 years (10–18 years). The mean follow-up period was 14.5 months (6–36 months). Results: Thirty hips had excellent and good clinical and radiographic outcomes with respect to hip function and radiographic parameters. Two patients had fair to poor clinical outcome including three patients who developed Avascular Necrosis (AVN). The difference between those who developed AVN and those who did not develop AVN was statistically significant in postoperative clinical scores (p = 0.0000). The mean slip angle of the femoral head was 52.5° ± 14.6 preoperatively and was corrected to a mean value of 5.6° ± 8.2° with mean correction of 46.85° ± 14.9° (p = 0.0000). The mean postoperative alpha angle was 51.15° ± 4.2° with mean correction of 46.70 ± 14.20 (p = 0.0000). In our series, the mean postoperative Harris hip score (HHS) was (96.16 ± 9.7) and the mean improvement was (29.6 ± 9.6) (p = 0.0000). Conclusions: The modified Dunn procedure allows to restore the normal proximal femoral anatomy by complete correction of the slip angle. This technique may reduce the probability of secondary osteoarthritis and femoroacetabular cam impingement.

The Outcome of Modified Dunn's Procedure for Moderate and Severe Slipped Capital Femoral Epiphysis

“…Implant failure did not occur in our series. This coincided with the findings of Cosma et al [19] and Elmarghany et al [20] , but did not coincide with the findings of many other authors [3,5,6,24,28,34] , who reported implant failure in their studies ( Table 4). The ideal osteosynthesis in the modified Dunn procedure has not been well established [5] .…”

“…Sankar et al [24] recorded open osteoplasty of deformity secondary to AVN in one case (3.7%), core decompression for AVN in one case (3.7%), revision of failed osteosytheses and removal of protruded implants in nine cases (33.5%) and total hip arthroplasty after AVN in one case (3.7%). Elmarghany et al [20] reported three reoperations in their series; removal of the protruded screws and arthro-diastasis after osteonecrosis in one case, debridement and screw removal for a case of late deep infection and readjustment of bad reduction in one case, (Table 4).…”

“…Other surgical alternatives for treatment of moderate and severe SCFE exist, including in situ pinning [2,5] , in situ pinning followed by a staged femoral osteotomy [5] , in situ pinning combined with basal junction. A modified Dunn procedure has been introduced to achieve these optimal goals [2,7,13,19,20,28,33] . However, this technique is, technically challenging and more invasive than in situ pinning, with some inherent risk of AVN due to the proximity to the lateral retinacular vessels [2,4,24] .…”

“…Increasing recognition of FAI and chondro-labral damage even after mild SCFE [3,[14][15][16][17][18] has led to a reconsideration and change of the objectives of treatment of SCFE. The ideal treatment would involve stabilizing the physis to prevent further epiphyseal slippage and correcting the deformity at the subcapital level, at the same time, to prevent FAI and early arthrosis, and to normalize hip range of motion (ROM) [3,[5][6][7]13,15,19,20] .…”

“…Ganz et al [22] introduced a modified Dunn's procedure that involved executing the original procedure after surgical dislocation of the epiphysis, because it is technically demanding to operate on the femoral neck to the epiphysis while it is located within the acetabulum. The modified Dunn's procedure is reported to achieve favorable postoperative outcome, although caution is needed because of the potential risk of femoral head avascular necrosis (AVN) [2,13,17,20,24] .…”