Step 1: In achalasia, the valve between the esophagus and stomach stays shut because the lower esophageal sphincter will not relax, and food backs up.
Step 2: The definitive surgical fix is to divide the muscle fibres at the gastroesophageal junction, allowing the valve to stay open. That operation is Heller's myotomy.
Step 3: The remaining options involve a throat pouch, a toe deformity and a knee joint procedure, none of which need a myotomy of the cardia.
\[\boxed{\text{Achalasia cardia}}\]