Retractable shield apparatus and method for a bone drill

A bone drill with retractable sheath comprising:

• a drill shaft having a proximal end and a distal end;
• a drill bit on said distal of said drill shaft, said drill bit extending coaxially from said distal end of said drill shaft;
• a hollow lumen through said drill shaft;
• an orifice in said drill shaft, said orifice being located adjacent said drill bit and in fluid communication with said lumen;
• a rigid, tubular sheath telescopically mounted over said drill shaft and said drill bit;
• a spring means on said sheath for resiliently urging said sheath over said drill bit into a shielding configuration for said drill bit, said sheath engaging a surface being drilled by said drill bit and being retractable against said spring as said drill bit penetrates said surface.

A method for shielding a bone drill during drilling into bone comprising the steps of:

• preparing a sheath for said bone drill, said sheath comprising a hollow tubular element having a proximal end and a distal end;
• mounting said proximal end of said hollow tubular element in a housing in sliding relationship to said housing;
• incorporating a spring in said housing, said spring resiliently pressing said proxima1 end of said hollow tubular element;
• inserting said bone drill into said sheath;
• engaging said distal end of said hollow tubular element against the bone;
• and
• drilling the bone with said bone drill while pressing said distal end against the bone thereby forcing said proximal end of said hollow tubular element into said housing against said spring thereby shielding said bone drill as said bone drill is drilling into the bone.