Acute lymphoblastic leukemia (ALL) is a cancer of the lymphoid line of blood cells characterized by the development of large numbers of immature lymphocytes. Symptoms may include feeling tired, pale skin color, fever, easy bleeding or bruising, enlarged lymph nodes, or bone pain. As an acute leukemia, ALL progresses rapidly and is typically fatal within weeks or months if left untreated.In most cases, the cause is unknown. Genetic risk factors may include Down syndrome, Li-Fraumeni syndrome, or neurofibromatosis type 1. Environmental risk factors may include significant radiation exposure or prior chemotherapy. Evidence regarding electromagnetic fields or pesticides is unclear. Some hypothesize that an abnormal immune response to a common infection may be a trigger. The underlying mechanism involves multiple genetic mutations that results in rapid cell division. The excessive immature lymphocytes in the bone marrow interfere with the production of new red blood cells, white blood cells, and platelets. Diagnosis is typically based on blood tests and bone marrow examination.ALL is typically treated initially with chemotherapy aimed at bringing about remission. This is then followed by further chemotherapy typically over a number of years. Treatment usually also includes intrathecal chemotherapy since systemic chemotherapy can have limited penetration into the central nervous system and the central nervous system is a common site for relapse of acute lymphoblastic leukemia.Treatment can also include radiation therapy if spread to the brain has occurred. Stem cell transplantation may be used if the disease recurs following standard treatment.
Failure of initial union, as when bone fragments are separated by soft tissue, may also lead to an atrophic non-union. Atrophic non-unions can be treated by stimulating blood flow and encouraging healing. This is often done surgically by removing the end layer of bone to provide raw ends for healing and the use of bone grafts. Oligotrophic nonunion
As the name implies, an oligotrophic nonunion demonstrates some attempt by the body to heal the fracture. These are thought to arise from adequate biology but displacement at the fracture site. Diagnosis
A diagnosis of nonunion is made when the clinician feels there will be no further bone healing without intervention. The FDA defines it as a fracture at least 9 months old that has not shown any signs of radiographic healing within the last 3 months. CT scans offer a closer look at the fracture and may also be used to evaluate how much of the fracture has healed. Blood tests can evaluate if the patient has adequate levels of nutrients such as calcium and vitamin D.  Blood tests can also look for markers of infection such as ESR and CRP. Treatment
Surgery
Currently, there are different strategies to augment the bone-regeneration process, however, there is no standardised clinical treatment guideline yet. Surgical treatment options include:
Debridement: radical surgical removal of necrotic or infected soft tissue and bone tissue is deemed essential for the healing process. Immobilization of the fracture with internal or external fixation.