Knee cap disllocation. Pgi they told us.

My son had 1st episode of knee cap dislocation on 3rd NOV 2015. HE WORE SUPPORT BRACE AND THEN HINGED BRACE. Braces were removed and he was fine. 2nd episode again on 27 March 2016 while playing.....he played football in park..wearing recurrent dislocation brace we consulted in GMCH 32 AND PGI ...They have suggested MPFL reconstruction surgery. we consulted in MAX Mohali ...Dr MANUJ WADHWA....he suggested to wait till my son attains the age of 17....as bones are growing now ....BY drilling the bone...bone's growth will be affected.....I m too confused what todo.....pl. suggest......if we donot go in for surgery then what are the risks.....will it happen again IN MAX and PGI they told us ......his muscles of second knee are also loose.....pl suggest what to do