An anchor assembly comprising: an externally threaded drive pin including: a shank , a head integrally connected to the shank , the head defining a mechanical engaging structure to enable rotation of the externally threaded drive pin , and an external helical thread formation integrally connected to and extending outwardly from the shank ; and an externally threaded anchor including: an elongated tubular body including an inner surface defining a longitudinally extending inner channel , the body including at least two independently movable gripping arms , a head integrally connected to and extending from a first end of the body and including an inner surface that defines a longitudinally extending inner channel that is aligned with the longitudinally extending inner channel of the body , the head including a mechanical engaging structure to enable rotation of the externally threaded anchor , the head also defining a drive pin head receiving recess configured to receive the head of the externally threaded drive pin , and an external helical thread formation integrally connected to and extending outwardly from part of the body , wherein the inner surface of the elongated tubular body is free of internal threads. an externally threaded drive pin including: a shank , a head integrally connected to the shank , the head defining a mechanical engaging structure to enable rotation of the externally threaded drive pin , and an external helical thread formation integrally connected to and extending outwardly from the shank ; and a shank , a head integrally connected to the shank , the head defining a mechanical engaging structure to enable rotation of the externally threaded drive pin , and an external helical thread formation integrally connected to and extending outwardly from the shank ; and an externally threaded anchor including: an elongated tubular body including an inner surface defining a longitudinally extending inner channel , the body including at least two independently movable gripping arms , a head integrally connected to and extending from a first end of the body and including an inner surface that defines a longitudinally extending inner channel that is aligned with the longitudinally extending inner channel of the body , the head including a mechanical engaging structure to enable rotation of the externally threaded anchor , the head also defining a drive pin head receiving recess configured to receive the head of the externally threaded drive pin , and an external helical thread formation integrally connected to and extending outwardly from part of the body , wherein the inner surface of the elongated tubular body is free of internal threads. an elongated tubular body including an inner surface defining a longitudinally extending inner channel , the body including at least two independently movable gripping arms , a head integrally connected to and extending from a first end of the body and including an inner surface that defines a longitudinally extending inner channel that is aligned with the longitudinally extending inner channel of the body , the head including a mechanical engaging structure to enable rotation of the externally threaded anchor , the head also defining a drive pin head receiving recess configured to receive the head of the externally threaded drive pin , and an external helical thread formation integrally connected to and extending outwardly from part of the body , wherein the inner surface of the elongated tubular body is free of internal threads. <EOS>