Ihab, who competed in the 81kg category, failed in two out of three Snatch attempts after appearing visibly in pain. He could not take part in the Clean & Jerk competition.
The injury marks another disappointing outcome for Egypt's 2016 Olympic bronze medalist, who was also forced to sit out the Tokyo Games earlier this year after the country's weightlifting federation was hit with a two-year ban over doping offences.
"I'm making no excuses … but I have to apologise," Ihab said on his Facebook page.
"Forgive me, you used to watch me winning medals in every single competition since 2014 and Egypt is a big name that only deserves gold medals.
"There are no room for mistakes when dealing with weights so, after consultations, we decided that I would not take any risks unless I was fully fit," he added.
Ihab is one of Egypt's most successful weightlifters, having won an Olympic bronze medal, a World Championship gold in 2017 and three silver world medals.
Earlier in the day, Ihab's compatriot Neama Said clinched three World Championship medals -- two golds and one silver -- in the women's 64kg competition.
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