Slipped Capital Femoral Epiphysis (SCFE ) Screw System
Slipped capital femoral epiphysis (SCFE) is a common hip disorder in the pediatric population in which the femoral epiphysis displaces from the metaphysis through the physis. The standard of care for SCFE is insitu fixation with a single cannulated screw. The use of standard cannulated screws became an issue due to the difficulty in removal, which has become more important because of the increasing number of hip preservation procedures (open hip dislocations) performed in SCFE for impingement.
The SCFE screw system has been designed specifically for the treatment of SCFE and offers greater advantage for fixation compared to standard cannulated screws. The SCFE screw system is also indicated for fracture fixation of large bones and large bone fragments, pediatric femoral neck fractures, intercondylar femoral fractures, and sacroiliac joint disruptions. Further indications may be tibial plateau fractures, ankle arthrodesis, and subtalar arthrodesis.
Fig 2 SCFE screw. Oval shaped washers are available for use in patients with poor bone quality to prevent countersinking of the screw head, allowing for greater screw angulation (up to 55) as well as 1 mm and 2 mm adjustments in screw positioning. The set includes the existing 2.8 mm guide wire that is 450 mm long and consists of a cobalt based material to provide additional stiffness and resistance to bending.
Fig 3 SCFE screw with oval washer. Specific instrumentation has been developed to aid in percutaneous insertion/removal of the screws. The new instruments include a 5.0 mm core/7.3 mm cannulated, and calibrated shaft-stepped drill bit, and 420.5 mm long. Additionally, the existing drill stop can be used with the drill bit.
A new trocar has been designed with a sharp tip allowing for easier insertion through the soft tissue, which helps to secure bone contact. The protection sleeve has been designed to interface with the new trocar.
A cannulated direct measuring device, allowing screw length to be measured off of the guide wire, is also included.
The 7.3 mm SCFE screw is compatible with the T40 StarDrive screwdriver which is also cannulated, and 350.5 mm long.
Fig 4 Mechanism. The SCFE screw is a 7.3 mm stainless steel cannulated shaft screw. The screw lengths range from 45130 mm, in 5 mm increments and screws are self-tapping.
Fig 5ab Single screws. A boy aged 11 years and 3 months presented with a limp and had had pain in the thigh for 8 weeks.
Case provided by Richard Reynolds, Detroit, USA
Fig 1ab Preoperative x-rays. 
Fig 2ab X-rays taken 2 months postoperatively. The mild slip was recognized and the stable slip was stabilized using a short threaded shaft screw with a washer to obtain compression across the physis. Pain resolved in the hip within a couple of days and weight bearing was resumed. 
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