Patent ID: 8641733

Claim:
A spinal fixation element comprising: a polyaxial screw comprising a cannulated elongated cylindrical body of a first diameter, said cannulated elongated cylindrical body comprising a threaded portion at a distal end and a head at the proximal end and wherein said head comprises a flat top and a semispherical bottom of a second diameter, wherein said second diameter is larger than said first diameter; and a washer comprising a cylindrical upper portion, a flared out lower portion and a semispherical through opening and wherein said semispherical through opening comprises a third diameter at the top, a fourth diameter in the middle and a fifth diameter at the bottom, and wherein said third diameter is slightly smaller than said second diameter, said fourth diameter is slightly larger than said second diameter and said fifth diameter is smaller than said second diameter, and wherein said washer is configured to receive and hold said head within said semispherical through opening, is non-removably attached to said head by swaging the cylindrical upper portion and is rotatable and positionable at an angle relative to said elongated body.