RT Journal A1 Ghert, Michelle A1 Petrisor, Brad T1 Subgroup Analyses: When Should We Believe Them? JF The Journal of Bone & Joint Surgery JO The Journal of Bone & Joint Surgery YR 2012 FD July 18 VO 94 IS Suppl 1(E) SP 61 OP 64 DO 10.2106/JBJS.L.00272 UL http://dx.doi.org/10.2106/JBJS.L.00272 AB