Make your own free website on Tripod.com

                                  DEPARTMENT OF ANATOMICAL SCIENCES

 

                                             AN321 - FORENSIC OSTEOLOGY

 

        BONE PATHOLOGY & ANOMALIES

 

 

                                                                 W. B. Wood

                                                              Senior Lecturer

                                                   The University of Queensland

 

 

 

INTRODUCTION

 

Most forensic anthropologists are not experts in the recognition of bony pathology but some have made it their specialty particularly in the area of paleopathology (Brothwell & Sandison 1967; Ortner & Putschar 1981; Steinbock 1976)

 

When pathology or bony anomalies are observed to be present then they must be fully described, photographed, radiographed and (in the case of pathology) examined microscopically so as to identify their nature and extent. Many of the chronic infectious diseases that leave their mark on bone have overlapping morphological features that make differential diagnosis almost impossible.

 

Needless to say, the advice of a consultant pathologist and radiologist should always be sought before any definitive conclusion is made.

 

Problems may arise where postmortem artifacts of bones may mimic disease processes (eg termite or root activity) and viceversa, or where anomalies of bone may be confused with antemortem or perimortem trauma e.g. from a gunshot wound (Taylor 1974, Duflou & Oettle 1990).

 

The presence of bony pathology or specific anomalies may assist in individual identification if antemortem records are available for comparison. It is only rarely however that the presence of bone pathology assists in the determination of the probable cause of death.

 

A good modern reference text for an introduction to bony disease and abnormalities is the book Outline of Orthopaedics by Crawford Adams (1981).

 

 

 

Skeletal pathology may be subdivided into disorders of bones and disorders of joints.


AETIOLOGY OF PATHOLOGICAL PROCESSES

 

            Genetic:                        inherited genetic defects

                                                somatic mutations

 

            Acquired:                     caused by environmental influences

 

 

TERMINOLOGY OF BONE & CARTILAGE PATHOLOGY & ABNORMALITIES

 

            Conditions that are handed on from parent to child due to a genetic

            abnormalities are called INHERITED conditions.

 

            Conditions that are the result of abnormal growth and development of

            cartilage or bone are called DEVELOPMENTAL abnormalities.

 

            Conditions that are present at birth are said to be CONGENITAL regardless of

            whether they are due to inherited genetic defects or developmental abnormalities

            caused by abnormal intrauterine environmental factors.

 

            Some bone pathology is LOCALISED while other affections are part of a

            GENERALISED disease process affecting the whole body.

 

 

            Diseases of bone result in abnormal bone formation, destruction, pathological

            fractures, dislocations or deformity.

 

 

CLASSIFICATION

 

            INHERITED Anomalies

 

            ACQUIRED Diseases

 

                        Inflammatory                - acute

                                                            - chronic

                        Neoplastic                    - benign

                                                            - malignant

                                                                        primary

                                                                        secondary

                        Degenerative

                        Nutritive

                        Obliterative (Circulatory)

                        Toxic

                        Metabolic (Nutritional & Endocrine)


INHERITED ANOMALIES

 

            These conditions are usually generalized throughout the body and may or

            may not be obvious at birth:

 

            Cartilage Dysplasias:             abnormal cartilage development

 

                        Achondroplasia (congenital dwarfism - marked shortening of the limbs)

 

                        Osteochondromatosis (multiple exostoses)

 

            Bone Dysplasias:                   abnormal bone development

 

                        Osteogenesis imperfecta (fragilitas ossium)

                        Fibrous dysplasia          - single or multiple cysts in bones

 

 

 

CONGENITAL ANOMALIES

 

            These conditions may be inherited or acquired (secondary). They are usually localized and

            obvious at birth:

 

                        Congenital dislocated hip (CDH)

                        Congenital genu varus/valgus (bow-leg; knock-kneed)

                        Reduction deformities - part or whole of a limb is absent

                        Fusion deformities - syndactyly; lobster claw hand, sacralization of L5

                        Extra digits - polydactyly

                        Club foot (Talipes equino varus)

                        Pes planus (flat-foot)

                        Spina bifida (absent vertebral arch)

                        Congenital scoliosis - usually due to a hemi-vertebra

 

 

ACQUIRED CONDITIONS

 

BONE & JOINT INFLAMMATION (OSTEITIS/ARTHRITIS)

 

            Acute Inflammation

 

                        Usually due to pyogenic (pus forming) organisms

 

                                                osteomyelitis

                                                periostitis

                                                septic arthritis


            Acute Inflammation (cont.)

 

                                    Signs:   redness, heat, pain, swelling, loss of function

                                                pus formation, bone and cartilage destruction

 

                        The bony lesions of acute osteomyelitis typically demonstrate an

                        involucrum of coarsely woven bone overlying or surrounding the surface of

                        the original bone and perforated by one or more sinuses (fistulae) for the

                        escape of pus from the medullary cavity. Embedded in the involucrum may                                 be one or more pieces of dead bone (sequestra).

 

                        Acute septic arthritis may lead to total joint disruption with fibrous or bony

                        ankylosis.

 

                        In acute periostitis, woven bone is laid down on the surface of the bony

                        cortex but there is no involvement of the medullary cavity and no formation

                        of sinuses.

 

 

            Chronic Inflammation

 

                        Pyogenic organisms (chronic osteomyelitis)

 

                                    Signs:

 

                                    recurrent or continuing symptoms and signs of inflammation                                                        persistent pus draining from sinuses

 

                                    destruction of bone and cartilage (osteolysis/chondrolysis) or

                                    abnormal bone formation and thickening (osteogenesis)

 

                        Tuberculosis

 

                                    a chronic infection of bone which results in bone and joint

                                    destruction

                                    usually there is little or no evidence of bony reaction

                                    attacks especially the vertebral column resulting in vertebral collapse                                          and the development of kyphosis (sharp posterior angulation of the

                                    spine)

                                    no associated evidence of sequestra formation, involucrum, or fusion

                                    of joints

 

                        Syphilis & yaws

 

                                    these are chronic infections of bone caused by related organisms.

                                    usually the disease focuses on the bones of the cranial vault, the                                                 facial skeleton or the tibia.

                                    there may be localized (fusiform swelling) of the shaft of a bone or

                                    generalized subperiosteal new bone formation due to periostitis,

                                    localised areas of bony destruction or rarefaction with dense

                                    thickening of the overlying cortex, diffuse sclerotic thickening of the

                                    whole bone. Radiologically the appearances vary from severe

                                    osteoporosis to dense sclerosis.

 

 

BONE & CARTILAGE NEOPLASMS (TUMOURS)

 

            True bony neoplasms result from the uncontrolled growth of bone, bone marrow

            and cartilage cells.

            Benign neoplasms are self limiting and tend to remain localised.

            Malignant neoplasms tend to spread throughout the body via tissue planes, body

            cavities and via blood and lymphatic vessels.

 

 

            Benign:

 

                        osteoma                       - occur in about 1% of people

                                                              especially common on the ectocranial surface

                                                              as a discrete mound of compact bone

 

                        osteochondroma           - arise at epiphysial lines, project at right angles and

                                                              resemble ossified tendons

 

                        NOTE: auditory exostoses (osteomata) may occur in the external

                                                auditory canal

 

 

            Malignant:

 

                        These may be either primary or secondary (metastatic)

                        Metastatic neoplasms with primary centers located in other organs or tissues

                        of the body are much more common in bone than primary bony neoplasms.

 

                        Primary:            osteosarcoma/blastoma/clastoma

                                                chondrosarcoma/blastoma

                                                multiple myeloma

                                                Ewing's tumour

 

                        Secondary:       these are usually of epithelial origin

 

                                                breast

                                                bronchus

                                                thyroid

                                                kidney

                                                prostate

 

            Most malignant neoplasms cause swelling of the affected bone associated with

            bone resorption (destruction or lysis). Radiographically they demonstrate localized

            radiolucency of bone tissue.

 

            Others may stimulate bone formation so that radioopaque areas may be present in

            the bone radiograph.

 

 

DEGENERATIVE BONE & CARTILAGE PATHOLOGY

 

            Osteoarthritis

 

                        most commonly associated with aged individuals and better termed

                        degenerative joint disease

                        characterized by periarticular bony lipping (osteophytes) and spur formation

                        often associated with eburnation (a polished ivory-like appearance of

                        synovial joint articular surfaces) due to the exposure of subchondral bone.                                 

                        may be localized (post traumatic) or more generalized and affecting

                        especially the vertebral column and large limb joints.

                        severe degrees may lead eventually to bony ankylosis of joints

 

 

 

            Rheumatoid Arthritis

 

                        this is a chronic non-bacterial inflammation of joints that nearly always

                        affects several joints at the same time (polyarthritis).

                        the cause is unknown but may be associated with autoimmune disease.

                        the condition often starts in the young adult and occurs more frequently in

                        females.

                        the condition causes thickening of the articular capsule, softening and                                         erosion of the articular cartilage.

                        eventually erosion and destruction of the subchondral bone and secondary

                        osteoarthritis may develop.

 

 

 

            Ankylosing spondylitis

 

                        a chronic disease of the vertebral column in which the ligaments of the

                        vertebral column become ossified and the intervertebral joints become

                        immobilized.


CIRCULATORY BONE DISEASE

 

 

            This is usually due to a disturbance of the blood supply (reduced or absent) to

            bone or cartilage.

 

            This may lead to avascular necrosis of bone or cartilage.

 

                        Keinbock's disease of the wrist (necrosis of the lunate bone)

                        Perthe's disease of the hip (necrosis of the proximal epiphysis of the hip)

 

                       

            Anaemias may also affect bone leading to a widening of the haematopoietic

            marrow spaces in bones (or the diploe in the cranium vault).

 

            Porotic hyperostosis (spongy hyperostosis) is a condition affecting the cranial

            vault which is probably anaemia related. There is a thinning and often

            complete destruction of the outer table of the cranial vault (especially in the

            parietal bones) with exposure of the spongy (sieve-like) diploe. Similar affects

            may appear in the orbital roof (cribra orbitalis) or endocranial surface (cribra

            cranii).

 

 

 

METABOLIC BONE DISEASE

 

 

            NUTRITIVE &/OR ENDOCRINE

 

            In these conditions there is a generalized reduction in bone mass as a result of

            inadequate osteoid production or mineralization, or of excessive demineralisation of

            bone.

 

 

            Osteoporosis:

 

                        a generalized loss of calcium from the bones especially in

                        postmenopausal women.

                        multifactorial in aetiology, with hormonal, dietary and reduced activity all

                        playing a part.


            Osteomalacia:

 

                        Due to deficient calcium absorption and/or metabolism

 

                                    Rickets (lack of vitamin D) causes softening and bending of bones

                                    due to excessive production of osteoid and a failure of osteoid tissue                                          to ossify (calcify).

                                    Skeletal effects are most obvious in the long bones, which become

                                    bent and distorted.

 

                                    Adult osteomalacia - causes generalized osteoporosis & crush

                                    fractures of vertebrae, or stress fractures of ribs, sternum & pelvis.

                                    Renal rickets

 

 

            Scurvy:

 

                        Due to insufficient intake of Vitamin C which is essential for the production

                        of collagen and therefore of osteoid.

 

                        Usually presents as cortical thinning and pathological fractures especially in

                        infants and young children.

 

 

 

            Hyperparathyroidism (Osteitis Fibrosa Cystica)

 

                        Due to excess production of parathyroid hormone.

 

                        There is loss of mineralized bone due to overactive osteoclastic resorption

                        There is generalized osteoporosis and the development of cystic lesions

                        throughout the bones.

 

 

            Hyperpituitarism:

 

                        Gigantism:

 

                        Due to overproduction of somatotrophic hormones (e.g. growth hormone) in

                        the growing child.

                        All the bones become excessively large.

 

 

                        Acromegaly:

 

                        Similar cause as for gigantism but only when it develops in adult

                        individuals after the growth epiphyses have closed.

                        Results in an individual with excessively large mandible, hands and feet.

 

 

            Paget's disease:

 

                        a very common bone disease (4% over 50yr olds in the UK)

                        uncertain aetiology

                        characterized by disordered bone architecture associated with:

 

                                    bone thickening, deformity,

                                    pathological fractures

 

            Gouty arthritis:

 

                        a metabolic disease due to abnormal urate metabolism. Results in the

                        deposition of urate crystals in the periarticular tissues associated with acute

                        inflammatory arthritis.

 

 

TOXIC DISEASE

 

                        Metal poisoning eg lead, mercury, bismuth, and phosphorus, often cause

                        metaphysial (and occasionally diaphysial) bands of increased density.

 

                        Fluoride intoxication may cause diffuse sclerosis with undulating periosteal

                        reaction.

 

 

REFERENCES

 

Brothwell D & AT Sandison 1967 Diseases in Antiquity CC Thomas Springfield Illinois

 

Crawford Adams J 1981 Outline of Orthopaedics  9th Edition, Churchill Livingstone

 

Crawford Adams J 1978 Outline of Fractures  7th Edition, Churchill Livingstone

 

Duflou J & THG Oettle 1990 "Bony Foramina in Forensic Medicine". Paper (No A553)

presented at the 12th Meeting of the International Association of Forensic Science Adelaide 1990

 

Ortner DJ & WGJ Putschar 1981 Identification of Pathological Conditions in Human Skeletal Remains  Smithsonian Contributions to Anthropology No 28  Smithsonian Institution Press Washington DC

 

Steinbock RT 1976 Paleopathological Diagnosis and Interpretation. CC Thomas

 

 

Taylor HL 1974 "The Sternal Foramen: The Possible Forensic Misinterpretation of an Anatomic Abnormality" JFS 19(4):730-734