Abstract

INTRODUCTION

To evaluate the relationship between the stability of the physis and the number of screw threads passing across the physeal line in the treatment of slipped capital femoral epiphysis (SCFE) with single screw fixation.

METHODS

Thirty three hips of 25 patients who had undergone insitu fixation in SCFE were included the study. The mean age and follow up was 12.33 years old (range, 7–16) and 42.24±16.65 months, respectively. The hips were grouped regarding to chronicity; acute, acute on chronic and chronic slips. With regards to the stability of the slip, the patients were also regrouped. Preoperative and postoperative both antero-posterior and frog leg pelvis radiographies were evaluated to measure Southwick slip angles and the number of screw threads.

RESULTS

Metabolic or hormonal disease was present in 13 patients. During the follow up four of the hips were reoperated due to the insufficiency of the screw threads passing across the physeal line. The mean number of the screw threads was 1,85 (range, 0–3) for the revised hips and 3.87 (range, 2–5) for the rest. The mean slip angle was 37.88°±15.2° preoperatively. Postoperatively, the angle was reduced to 29.00°±16.41° (p=0.0001). Postoperative slip angle determined significantly different between chronicity groups (p=0.019). In the acute slip group, mean slip angle was 21.00°±11.08° whereas in the chronic group was 42.22°±17.98° (p=0.009).

DISCUSSION AND CONCLUSION

It was concluded that in surgical treatment of SCFE with a single screw, the number of screw threads passing across the epiphyseal line should be at least four; otherwise fixation would not be stable enough.