Page 33 - Slipped Capital Femoral Epiphysis Pathogenetic and Clinical aspects

in life [19, 95]. In the long-term, osteoarthritis can be triggered after repetitive early
mechanical abrasion of the prominent metaphysis (cam-type lesion) against the
anterior rim of the acetabular cartilage [64, 140]. Although most slips have some
remodelling potential this may not be enough to prevent osteoarthritis [5, 14, 155].
Bone peg epiphysiodesis was compared in a long-term outcome study to single 2 screw fixation. The outcome was good (HHS, no pain, no total hip replacement) in
69% of cases and there was no significant difference between these two techniques in chronic SCFE [147].
The functional outcome measured by mean Iowa hip score in 105 patients with one single screw fixation in stable SCFE grade 3 (more than 60 degrees slip) showed good or excellent results in 80 patients with a minimum follow-up from 5 years. Younger age, with more remodelling capacity, and adequate placement of the screw appeared related to a good outcome [21].
Larson et al. [60] reported that in their institution all grades of SCFE were treated by only single screw fixation. Reconstructive surgery, femoral osteotomy, surgical hip dislocation and total hiparthroplasty, was necessary in 21 (12 %) of 176 hips after a FU time of 16 years, but one third of the remaining patients complained commonly about persistent mild hip pain. There is a direct relationship between the degree of displacement in SCFE and the outcome and development of degenerative disease [19, 22, 42, 56, 147].
Functional impairments in SCFE patients can be found even after growth arrest. Westhoff [149] performed gait analysis on 37 patients with SCFE after growth arrest. The worst radiological subgroup revealed an increase in step width, sagittal range of motion of the pelvis and foot progression causing significant deviation in gait parameters. This could be due to the disease or be specific to the constitution of these patients (high BMI).
Femoro-acetabular impingement (FAI).
FAI after SCFE is caused by the abnormal morphology of the femur head after the slip, which can result in increased local contact forces between the metaphyseal bump of the femoral head and the anterior labrum of the acetabulum during hip motion. Prevalence of FAI, by a camtype deformity (bump formation on the edge of the femoral head and neck), was also found in asymptomatic volunteers and is reported in 14-24% of cases. [126].
In recent literature, the occurrence of FAI has been described in detail. It is caused by posteromedial displacement of the femoral head leaving an anterolateral
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