Does the number of engaged screw threads affect the stability of slipped capital femoral epiphysis insitu fixation?

Abstract

Objective: The management of slipped capital femoral epiphysis (SCFE) frequently seen in obese adolescents is fixation with cannulated screw. In this study, it was aimed 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 SCFE patients who had undergone in situ fixation with cannulated screw were included in the study. The mean age and follow up were 12.33 years (range, 7-16) and 42.24±16.65 months, respectively. The hips were grouped regarding to chronicity; acute, acute on chronic and chronic slips. The patients were also regrouped regarding the stability of the slip. Pre-and postoperatively both antero-posterior and frog leg pelvis radiographies were evaluated to measure Southwick slip angles and the number of screw threads. Results: Metabolic or endocrinologic pathologies were observed in 13 patients. During the follow up four 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 angles were 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 it was 42.22°±17.98° (p=0.009). Conclusion: It was concluded that in the 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.Key words: Slipped capital femoral epiphysis, adolescent obesity, in-situ fixation, screw threads ÖZ Amaç: Adölesanlarda obezite ile birlikte sık görülen bir hastalık olan femur başı epifiz kaymasının (FBEK) tedavisi kanüllü vida ile in-situ tespittir. Bu çalışmada, tek kanüllü vida ile tedavi edilen FBEK'lerde epifizi geçen yiv sayısı ile stabilitenin ilişkisini saptamak amaçlanmıştır. Yöntem: 2008-2013 yılları arasında kanüllü vida ile opere olan 25 FBEK hastasının 33 kalçası pre op ve post op olarak klinik ve radyolojik olarak değerlendirildi. Kalçalar etiyolojisine göre akut, kronik zeminde akut ve kronik olmak üzere gruplandırılırken, stabilite açısında gruplandırıldılar. Radyolojik olarak kalça tam AP ve frog-leg pozisyonlarında, operasyon öncesi ve sonrası Southwick açıları (epifiz-diafiz açısı), operasyon sonrası epifiz hattını geçen yiv sayıları ölçüldü. Bulgular: On üç olguda metabolik veya endokrinolojik patoloji gözlendi. Tek kanüllü vida kullanılarak opere edilen olguların 4'ünde cerrahi sonrasında kayma açılarında artış olduğu göz-lendi ve revize edildi. Bu 4 kalçada ön-arka ve frog-leg pozisyonlardaki grafilerde değerlendiri-len epifiz hattını geçen yiv sayısı ortalaması 1.85 idi. Kayma açısında artış olmayan 2...

Relationship between Treatment Age and Poor Outcome in Slipped Capital Femoral Epiphysis

“…In recent studies conducted in Turkey, the main fixation method is closed fixation in situ [6,23,24]. In all our patients, we used 6.5-mm screws in the supine position under the guidance of fluoroscopy and avoided the use of special traction tables.…”