St Kilda has confirmed that star forward Aaron Hamill has undergone arthroscopic knee surgery.The 29-year old experienced soreness in his right knee last week as the Saints commenced pre-season training and after seeking medical advice, opted for the procedure.Hamill was restricted to just nine games for St. Kilda this year including the club's 18-point loss to Melbourne in the first week of the finals.His 2006 season was punctuated by an arthroscopy which saw him miss 13 games after rupturing his posterior cruciate ligament against Geelong in round seven.It has been a continuation of injury woes for Hamill who only played 12 games the previous year after suffering a similar leg injury.The club will release further information on the extent of the injury once results are known.