[Mid-Term Results of Treatment of Severe Grades of Slipped Capital Femoral Epiphysis without Surgical Hip Dislocation].

PURPOSE OF THE STUDY To evaluate the results of treatment of acute and chronic severe slips of slipped capital femoral epiphysis. The tested hypothesis was that the results will be comparable with the methods using surgical hip dislocation. MATERIAL AND METHODS In the period 1996-2014, 26 patients were treated for severe slips ( >60°). Boys prevailed (2:1) and were older on average (the mean age 13.8 vs.12 years). Chronic stable slips prevailed (16 patients) and were followed by acute-on-chronic slips (7 patients) and with acute slips (3 patients). The acute unstable slips were treated using closed reduction and transphyseal fixation. The acute-on-chronic slips were treated using closed reduction and fixation (2 patients) and subcapital osteotomy (5 patients), respectively. Chronic slips were treated as follows: with subcapital osteotomy (10 patients); with intertrochanteric femoral osteotomy (5 patients); and with transphyseal fixation without correction (1 patient). 22 patients were treated concurrently on the contralateral side as a prevention or to treat the slips. The follow-up ranged from 20 months to 13 years. The clinical results were evaluated according to four scores: 1) our own score (NB score) based on the reduction of ROM, shortening of extremity and limitations in activities; 2) Merle d'Aubigne score; 3) Harris hip score (HHS); 4) non arthritic hip score (NAHS). In the radiological evaluation, correction of slip angle, alpha-angle, avascular necrosis (AVN) and grade of arthrosis according to Toennis were observed. RESULTS According to the NB score 10 excellent results (38%), 11 very good results (42%), one good and one satisfactory result (4%) and 3 unsatisfactory results (11%) were achieved. According to the other scores the following results were reported: a) excellent: D'Aubigne-Postel - 19 (73%); HHS - 20 (77%); NAHS - 21(81%), b) good: D'Aubigne and HHS- 3 (11%); NAHS - 2 (8%), c) satisfactory: D 'Aubigne - one (4%), HHS and NAHS 0, d) unsatisfactory: D'Aubigne, HHS and NAHS - 3 (11%). The evaluation of surgical methods shows that the best results were achieved by closed reduction of acute slips (with 80% excellent results). The result of transphyseal fixation without reduction was satisfactory only. The intertrochanteric osteotomy led mostly to very good results (80%) and then to the excellent results (20%). After subcapital osteotomy, mostly excellent and very good results (40% each) were reported, followed by two unsatisfactory results (13%) and one good result (7%). As concerns the slip reduction and alfa angle, the best results were achieved by closed reduction and subcapital osteotomy. The FAI was observed/ in 10 patients. Arthrosis was observed as follows: grade I in 8 patients, grade II in 3 patients. The AVN was present as segmental in 4 patients (15%) and as complete in two patients (8%), namely in one after closed reduction and in one after subcapital osteotomy. Dislocations of the hip occurred twice after subcapital osteotomy. Chondrolysis and hip ankylosis were reported in one patient after subcapital osteotomy. DISCUSSION The hypothesis was confirmed because the results of treatment of severe slips without hip dislocation are comparable with procedures using the surgical hip dislocation. The results correspond with large published cohorts of patients in terms of correction as well as the rate of complications. CONCLUSIONS The best results were achieved by closed reduction of acute slips where no complications were present. Subcapital osteotomy without surgical dislocation is comparable with modified osteotomy with surgical hip dislocation. Intertrochanteric osteotomy represents an efficient method in treating grade II slips. Transphyseal fixation without slip correction cannot be recommended in treating severe slips. Key words: slipped capital femoral epiphysis, severe grades of slip, subcapital femoral osteotomy, intertrochanteric femoral osteotomy, closed reduction of slip.