Intraoperative Monitoring of Epiphyseal Perfusion in Slipped Capital Femoral Epiphysis: Surgical Technique.

INTRODUCTION

Intraoperative monitoring of epiphyseal perfusion in slipped capital femoral epiphysis (SCFE) is a procedurally simple and readily accessible percutaneous technique to accurately guide decision-making and help to prevent osteonecrosis.

STEP 1 PATIENT PREPARATION AND POSITIONING: Following anesthesia induction, position the patient and assess the physeal stability fluoroscopically to determine the need for a reduction.

STEP 2 GUIDEWIRE PLACEMENT: Place a 3.2-mm threaded guidewire from the anterolateral aspect of the femur to provide initial stability of the slipped epiphysis.

STEP 3 INITIAL SCREW INSERTION: Insert a cannulated 7.0-mm stainless steel screw over the guidewire to a point just past the physis.

STEP 4 PREPARATION AND INSERTION OF THE ICP PROBE: Once the screw has been inserted to obtain provisional stability of the physis, remove the guidewire and insert a sterile ICP probe down the screw shaft to assess the epiphyseal perfusion.

STEP 5 HIP DECOMPRESSION: If a perfusion pressure and waveform cannot be obtained, perform decompression of the hip capsule by either aspiration or capsulotomy.

STEP 6 EPIPHYSEAL PERFUSION REASSESSMENT: Following the capsulotomy, reinsert the ICP probe and reassess the epiphyseal perfusion.

STEP 7 FINAL SCREW ADVANCEMENT: Once epiphyseal blood flow can be confirmed, reintroduce the guidewire to its previous depth and advance the screw to the final measured depth.

RESULTS

Utilizing this technique over a 5-year period, >35 patients were treated with the described technique, and 23 of them, including 29 hips, were included in our referenced prospective study3.