The pars plana is the second ossification center along the navicular tuberosity. On imaging, the pars plana can be found in 4-12% of normal feet. The pars plana itself does not create a problem, but can become problematic in two situations: 1) in adulthood, the medial bony prominence can become mechanically problematic when wearing shoes, but may become problematic after an injury. 2) the fibrous attachment point of the pars plana is subjected to excessive stress and microdamage occurs, and which in turn exhibits symptoms. According to the degree of ossification of the developmental process, the paracarpal bone is generally classified into 3 types. One is completely separate from the navicular tuberosity, with the posterior tibial tendon tissue between the two. The second is that it is connected to the navicular tuberosity by cartilage. The third is the formation of a pseudo-joint with the medial navicular tuberosity. Treatment: If the disease is recognized in time after the injury, braking is usually performed for 3 weeks. If there is still enough persistent pain it is recommended that minimally invasive drilling can be performed while braking for 45 days afterwards, while some patients still have pain, surgical treatment can be considered, i.e. pars plana osteotomy. The type of pseudarthrosis that forms can be treated with pars plana resection and reconstruction of the posterior tibial tendon stop.