Human health and medicine

Osteopathic manipulative treatment

Osteopathic manipulative treatment (OMT), also known as osteopathic manipulative medicine, is hands-on treatment by osteopathic physicians using techniques like muscle energy and myofascial release to correct somatic dysfunction.

Osteopathic medicine in the United States

Osteopathic medicine in the United States, also called American osteopathy, is a medical branch whose DOs have full physician licenses and extra training in hands-on manipulative treatment.

Osteopathic Physicians

Osteopathic physicians (DOs) are fully licensed U.S. physicians trained in osteopathic medicine, founded by A.T. Still in 1874; they prescribe, perform surgery, practice all specialties, and comprise about 11% of U.S. physicians.

Osteopathy

Osteopathy, founded by Andrew Taylor Still in 1874, is a healthcare system using osteopathic manipulative treatment; in the US DOs are fully licensed physicians, elsewhere osteopaths are manual therapists, with best evidence for musculoskeletal pain.

Osteopenia

Osteopenia, or low bone mass, is reduced bone mineral density with a T-score between −1 and −2.5, below normal but above the osteoporosis threshold; diagnosed by DXA, managed with exercise, calcium, vitamin D, and selective drug treatment.

Osteopetrosis

Osteopetrosis, or marble bone disease and Albers-Schönberg disease, is a rare inherited disorder causing overly dense, brittle bones from defective osteoclasts, with severe infantile autosomal recessive and milder autosomal dominant forms.

Osteopetrosis with renal tubular acidosis

Osteopetrosis with renal tubular acidosis, also called carbonic anhydrase II deficiency, Guibaud-Vainsel syndrome, or marble brain disease, is a rare autosomal recessive CA2-gene disorder combining osteopetrosis, mixed proximal and distal RTA, and cerebral calcification.

Osteoplasty

Osteoplasty is a surgical procedure that reshapes, repairs, or grafts bone to restore skeletal structure and function, covering open bone grafting and percutaneous cement injection for painful lesions.

Osteoporosis

Osteoporosis, also called postmenopausal or senile osteoporosis, is a silent bone disease of low bone mass (T-score ≤ −2.5) and deteriorated microarchitecture causing fragility fractures; 8.9 million fractures occur yearly, and bisphosphonates, denosumab, and anabolics reduce risk.

Osteoporosis of disuse

Osteoporosis of disuse (disuse osteoporosis, ICD-11 FB83.12): bone loss from lack of mechanical loading in spinal cord injury, immobilization, bed rest, and spaceflight, with high resorption, low formation, and incomplete recovery.

Osteoporosis-oculocutaneous hypopigmentation syndrome

Osteoporosis-oculocutaneous hypopigmentation syndrome (OOCHS, Hernández-Fragoso syndrome, OMIM 601220) is an autosomal recessive rare disease combining congenital hypopigmentation, visual impairment, osteoporosis, and skeletal anomalies, with only a few reported cases.

Osteoporosis-pseudoglioma syndrome

Osteoporosis-pseudoglioma syndrome (OPPG, OMIM 259770) is a rare autosomal recessive LRP5 disorder causing congenital blindness and severe juvenile osteoporosis with fractures; treated with bisphosphonates.

Osteoradionecrosis of the mandible

Osteoradionecrosis of the mandible (mandibular ORN), exposed nonhealing irradiated jaw bone lasting over 3 months after head and neck radiotherapy; incidence 4-8%, treated with PENTO drugs or free-flap reconstruction.

Osteosarcoma

Osteosarcoma, also called osteogenic sarcoma, is the most common primary malignant bone tumor, arising from osteoblasts that produce osteoid. It affects adolescents in long bones near the knee; chemotherapy plus surgery raised five-year survival from about 20% to 50-60%, plateaued for decades.

Osteosclerosis

Osteosclerosis (ostéosclérose, osteoesclerosis): increased bone density causing hardening or fragility, coded ICD-11 FB80.4. Coined by Lobstein in 1833 opposite osteoporosis; hereditary (osteopetrosis, sclerosing dysplasias) or acquired (fluorosis, myelofibrosis, osteoblastic metastases).

Osteosclerotic bone dysplasia

Osteosclerotic bone dysplasia, also called Raine syndrome (OMIM 259775), is a rare autosomal recessive neonatal bone dysplasia caused by FAM20C mutations, marked by generalized osteosclerosis, facial dysmorphism, intracerebral calcifications, and lethal or non-lethal hypophosphatemic rickets forms.

Osteosclerotic metaphyseal dysplasia

Osteosclerotic metaphyseal dysplasia (OMD, OSMD, OMIM 615198) is an ultrarare autosomal recessive osteopetrosis caused by LRRK1 mutations, marked by metaphyseal osteosclerosis, osteopenic diaphyses, developmental delay, and fewer than 10 reported cases.

Osteosynthesis

Osteosynthesis is the surgical joining of broken bone fragments with implants such as plates, screws, intramedullary nails, or wires, holding them firmly in position while the fracture heals.

Osteotomy

An osteotomy is a surgical operation in which a bone is cut and realigned, such as the high tibial osteotomy for knee arthritis, to relieve pain and delay joint replacement.

Oswestry Disability Index

The Oswestry Disability Index (ODI) is a ten-section patient questionnaire measuring how low back pain limits daily functioning, first published in 1980 and available in over 30 languages.

Otamixaban

Otamixaban (FXV673, XRP0673) is an intravenous, reversible direct factor Xa inhibitor (Ki 0.5 nM) developed by Sanofi-Aventis for acute coronary syndrome; its phase 3 TAO trial showed no efficacy benefit and doubled bleeding, so it was never approved.

Otelixizumab

Otelixizumab (ChAglyCD3, TRX4) is an aglycosylated humanized anti-CD3E monoclonal antibody tested in new-onset type 1 diabetes; high doses preserved C-peptide but caused EBV reactivation, and phase III trials missed endpoints.

Otenabant

Otenabant (CP-945,598), Pfizer's selective CB1 cannabinoid receptor antagonist (Ki 0.7 nM), was trialed for obesity and NASH but its clinical program was terminated in 2008 after rimonabant's psychiatric safety withdrawal.

Oteracil

Oteracil (potassium oxonate, oxonic acid) is the OPRT-inhibiting gastrointestinal-protective component of S-1 (tegafur/gimeracil/oteracil, TS-1, Teysuno), combined in a 1:0.4:1 molar ratio to reduce 5-FU gut toxicity.

Oteseconazole

Oteseconazole (Vivjoa, VT-1161) is an oral tetrazole CYP51-inhibiting antifungal approved by FDA in 2022 to reduce recurrent vulvovaginal candidiasis in females not of reproductive potential, with phase 3 recurrence rates near 4-7% versus about 40% on placebo.

Other acquired deformities of limbs

Other acquired deformities of limbs (ICD-11 FA31; ICD-10 M21) is a WHO classification category grouping non-congenital limb deformities: valgus, varus, flexion deformity, wrist drop, foot drop, flatfoot, clawhand, clubfoot, and unequal limb length.

Other acute osteomyelitis

Other acute osteomyelitis is ICD-11 code FB84.1, classifying acute bone infection other than acute haematogenous osteomyelitis, with site-specific child codes from femur to skull, indexed terms including acute osteitis, and siblings FB84.0 through FB84.5.