Page 29 - Slipped Capital Femoral Epiphysis Pathogenetic and Clinical aspects

Prophylactic pinning of the contralateral hip.
Bilateral SCFE involvement is reported between 15 and 50% in the literature [11,
69]. Controversy exists over prophylactic pinning. Prophylactic pinning can be
safer and more preferable to observation alone to prevent AVN and slip severity
on the contralateral side [11, 154, 159]. Alternatively, one must consider the 2 possible complications caused by prophylactic pinning like chondrolysis, AVN
and peri-implant fracture [59, 119]. Generally, most articles suggest observation seems to be the most appropriate treatment on the contralateral site. Observation might not be appropriate in a very young child, a child with a known metabolic or endocrine disorder or in a child with a severe unstable unilateral slip. In these situations contralateral screw fixation might be warranted [43, 47, 55]. Wensaas et al. [147] reports good long-term results after untreated contralateral hip in unilateral SCFE. Within their group, only 5 of 40 patients with a mean FU of 36 years were present with a poor (missed SCFE?) outcome on the contralateral side, although the Nötzli’s alpha angle was higher in the contralateral hip group compared to normal hips. Vlachopoulos et al. [144] reported persisting growth after prophylactic single cannulated screw fixation (10 out of 11 patients), necessitating a thorough follow up of the prophylactic pinning on the contralateral side. Some authors recommend a prophylactic percutaneous screw fixation on the contralateral side if the posterior sloping angle (PSA) is 12-19 degrees or higher (see etiology) [58, 98, 102, 162].
Removal of screw implants in SCFE.
There is no evidence promoting routine removal of implants in children, especially in SCFE where the complication rate of removal is high (34%) [111]. Removal of screw implants before closure of the physes can cause a further slip in the physes [29]. Despite these known complications, in the survey of the Netherlands and the UK, 21% (33 versus 17%) respondents admitted to remove the screw implants whilst the POSNA reported that in 12% [150].
Secondary reconstructive treatment.
Different osteotomies have been described in the literature for stable SCFE, before or after the physes are closed. Sonnega et al. [131] performed a survey among the members of the European Pediatric Orthopaedic Society (EPOS) and state that the spread of more complex techniques is slow among the participants of the survey. Numerous osteotomy techniques have been described: before or after the physis is closed, one stage osteotomy with screw fixation, and osteotomies on
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