The troublesome problem has hindered Birch’s return campaign with the Bucks.
Birch, 25, has been limited to just nine National League North starts this season and has not featured in the last two games.
He has seen a specialist over the issue and is set to miss at least the next few games while the issue is further explored.
Birch was brought back to the New Bucks Head by former boss Gavin Cowan after turning out for league rivals Chorley.
Birch, who is from Whitchurch, will miss crunch upcoming home matches against Darlington and Bradford PA.
Loan signing Jordan Piggott filled in at right-back in Tuesday’s defeat at Gateshead, with Ross White the other contender on that flank.