A tendon anchoring system, comprising: an anchor assembly having a sheath with at least two sidewalls and at least first and second slots ; and an inserter tool having an outer shaft (306, 306', 306") with an inner lumen extending therethrough, an inner shaft having first and second prongs formed on a distal end thereof, the prongs being sized and dimensioned to extend along the first and second slots in the sheath , and a handle assembly coupled to a proximal end of the inner and outer shafts (310, 306, 306', 306"), the handle assembly having an actuator configured to axially move the inner shaft relative to the outer shaft (306, 306', 306") to thereby move the prongs between an extended position in which the prongs extend distally beyond a distal end of the outer shaft (306, 306', 306"), and a retracted position in which the prongs are retracted into the distal end of the outer shaft (306, 306', 306"); characterized in that: the least two sidewalls are at least partially separated by the at least first and second slots and define an inner lumen therebetween; the anchor assembly further comprises an expander configured to be received within the inner lumen of the sheath ; and the prongs are sized and dimensioned to extend distally beyond a distal end of the sheath when extending along the first and second slots . an anchor assembly having a sheath with at least two sidewalls and at least first and second slots ; and an inserter tool having an outer shaft (306, 306', 306") with an inner lumen extending therethrough, an inner shaft having first and second prongs formed on a distal end thereof, the prongs being sized and dimensioned to extend along the first and second slots in the sheath , and a handle assembly coupled to a proximal end of the inner and outer shafts (310, 306, 306', 306"), the handle assembly having an actuator configured to axially move the inner shaft relative to the outer shaft (306, 306', 306") to thereby move the prongs between an extended position in which the prongs extend distally beyond a distal end of the outer shaft (306, 306', 306"), and a retracted position in which the prongs are retracted into the distal end of the outer shaft (306, 306', 306"); an outer shaft (306, 306', 306") with an inner lumen extending therethrough, an inner shaft having first and second prongs formed on a distal end thereof, the prongs being sized and dimensioned to extend along the first and second slots in the sheath , and a handle assembly coupled to a proximal end of the inner and outer shafts (310, 306, 306', 306"), the handle assembly having an actuator configured to axially move the inner shaft relative to the outer shaft (306, 306', 306") to thereby move the prongs between an extended position in which the prongs extend distally beyond a distal end of the outer shaft (306, 306', 306"), and a retracted position in which the prongs are retracted into the distal end of the outer shaft (306, 306', 306"); characterized in that: the least two sidewalls are at least partially separated by the at least first and second slots and define an inner lumen therebetween; the anchor assembly further comprises an expander configured to be received within the inner lumen of the sheath ; and the prongs are sized and dimensioned to extend distally beyond a distal end of the sheath when extending along the first and second slots . the least two sidewalls are at least partially separated by the at least first and second slots and define an inner lumen therebetween; the anchor assembly further comprises an expander configured to be received within the inner lumen of the sheath ; and the prongs are sized and dimensioned to extend distally beyond a distal end of the sheath when extending along the first and second slots . <EOS>