H

H


H2O2 see hydrogen peroxide


H2-receptor antagonist drug e.g. cimetidine (Tagamet) and ranitidine (Zantac); used to heal gastric and duodenal ulcers and control symptoms of oesophageal reflux (heartburn); contraindicated in the use of local anaesthetics (they act as competitive inhibitors of hepatic enzymes that break down local anaesthetic compounds)


5HT1 serotonin


habituation reduction of a desired drug response, or the need for greater dose to achieve the early response, due to repeated use of the drug


haem iron-containing, oxygen-carrying, red-coloured constituent of haemoglobin


haemagglutination erythrocyte agglutination due to a specific erythrocyte antibody, or the effects of certain viruses


haemangioma congenital anomaly of skin or subcuticular tissues due to proliferation of vascular endothelium, forming a mass


haemarthrosis blood within a joint


haematocrit; Hct percentage, by volume, of cells within a blood sample


haematogenous spread spread of microorganisms via circulating blood


haematoma localized mass of extravasated and clotted blood, due to local tissue injury or trauma, blood vessel severance or rupture, failure to tie off or coagulate vessels during surgery or close deep areas of a surgical wound with soluble sutures; a large haematoma will act as a focus for infection; intramuscular haematoma predisposes to local fibrosis ± ectopic calcification


haematuria blood in urine


haemodialysis dialysis of soluble substances and water from the blood, by diffusion through a semipermeable membrane


haemoglobin; Hb red-coloured protein within erythrocytes (6% haem; 94% globin); transports oxygen (as oxyhaemoglobin) from lungs to tissues, where oxygen is readily given up and oxyhaemoglobin is reduced to haemoglobin (see glycosylated haemoglobin)


haemolytic causing lysis of red blood cells


haemolytic disease of the newborn potentially severe neonatal anaemia and jaundice due to antigenic destruction of erythrocytes


haemophilia inherited coagulation cascade disorder, characterized by lifelong tendency to haemorrhage





haemopoiesis formation and development of blood cells and platelets


haemorrhage bleeding


haemosiderin insoluble protein formed when fixed-tissue histiocytes ingest haematin (a haem derivative); causes haemosiderosis


haemosiderosis brown (light tan through to darkest brown) discoloration of skin due to accumulation of haemosiderin; characteristic of very long-term chronic inflammation (of any cause) in skin; often affects lower one-third of leg in venous hypertension or compromised venous function of lower-limb


haemostasis deliberate arrest of blood flow, e.g. during surgery


haemostat (1) alginate impregnated with calcium ions; wound dressing used to promote clotting of plasma proteins


haemostat (2) instrument that arrests haemorrhage by applied pressure, e.g. Spencer–Wells forceps


haemostatics topical agents for the arrest of minor haemorrhage; e.g. direct digital pressure; astringents (e.g. 15% ferric chloride); protein precipitators (e.g. 25% silver nitrate); 10 vol hydrogen peroxide; >5% potassium permanganate solution; dressings (e.g. calcium alginate [Kaltostat])


Haglund’s deformity; retrocalcaneal exostosis; pump bump hypertrophy or prominence of posterior superior lateral border of calcaneum; characteristic of earlier Sever’s disease, or chronic mechanical irritation from shoe counter against the heel during gait in a foot that overpronates at the subtalar joint (see compensated rearfoot varus; mobile pes cavus)


Haglund’s syndrome see syndrome, Haglund’s


hair follicle invagination of fetal epidermis and dermis to form a deep, narrow pit, from which a hair papilla (hair root) and resultant hair shaft develop, and into which the local sebaceous gland opens


half-life see radioactive isotopes


half-value distance; H-VD the tendency for ultrasound (US) intensity to become absorbed by surrounding tissues, and attenuate to the point of therapeutic ineffectiveness; US penetration is ∼ 4 mm at 3 MHz, and 11 mm at 1 MHz in irregular soft tissues; the higher the US frequency, the greater its absorption by surrounding tissues, and the greater the rate of its conversion into heat energy at tissue interfaces


hallux great toe; first toe


hallux abductovalgus; HAV biplanar first-ray deformity, where the tip of the hallux is deviated on the transverse plane (away from body midline) in conjunction with frontal-plane axial rotation of the hallux about its longitudinal axis (i.e. the medial nail sulcus approaches the support surface) and transverse-plane deviation of the first metatarsal head towards the midline of the body (i.e. secondary to metatarsus primus varus); HAV is associated with a range of forefoot pathologies (Table H1 and Box H1; Figure H1) and may require surgical correction (Table H2)


Table H1 Features that predispose to hallux abductovalgus































Location Feature Predisposing factor
Intrinsic to the foot and lower limb Excess STJ and MTJ pronation Ankle equinus
Pes planovalgus
Forefoot varus
Metatarsus primus elevatus
Metatarsus primus varus
Pes cavus
Long second metatarsal/short first metatarsal
Functional hallux limitus
Adductus foot
  Structural anomalies within the lower limb that predispose to compensatory foot pronation External tibial torsion
Tibial varum
Genu varum/valgum, recurvatum
Femoral retroversion
Wide-based gait
Longer limb
  Trauma First MTPJ intra-articular damage
First MTPJ sprain (turf toe)
Subluxed second toe
Soft-tissue tears
Extrinsic to the foot and lower limb Inflammatory joint disease Rheumatoid disease
Psoriatic arthropathy
Gout
  Connective tissue disorders characterized by joint hypermobility Generalized hypermobility syndrome
Ehlers–Danlos syndrome
Marfan’s syndrome
Down’s syndrome
Osteogenesis imperfecta
  Neuromuscular disease characterized by the development of pes cavus or pes planovalgus Multiple sclerosis
Hereditary sensorimotor neuropathy (Charcot–Marie–Tooth disease)
Cerebral palsy
Poliomyelitis
Friedreich’s ataxia

STJ, subtalar joint; MTJ, metatarsal joint; MTPJ, metatarsophalangeal joint.



Box H1 Clinical features of hallux abductovalgus































MTPJ, metatarsophalangeal joint; IPJ, interphalangeal joint; PIPJ, proximal interphalangeal joint.



Table H2 Surgical options for the treatment of hallux abductovalgus



























Surgical approach Intervention Example procedure
Joint-destructive procedures Excision of base of hallux proximal phalanx
Arthrodesis
Keller
Screw arthrodesis
Joint-preserving procedures Closing basal wedge osteotomy, first metatarsal
Distal metatarsal osteotomy
Basal wedge osteotomy
Wilson; Austin
Ray alignment procedures Z osteotomy
Medial closing-wedge osteotomy, hallux
Scarf
Akin
Ray stabilization procedures Arthrodesis of first metatarsal/medial cuneiform joint Lapidus
Cosmesis Excision of medial eminence at head of first metatarsal (cheilectomy) Silver

There are over 100 named surgical techniques for the correction of hallux abductovalgus, most of which are modifications of a number of principles of approach.


hallux flexus uniplanar, sagittal-plane first-ray deformity, in which the first metatarsal head is dorsiflexed (metatarsus elevatus) and the hallux proximal phalanx is plantarflexed relative to the support surface; the distal phalanx of the hallux may be in either a neutral or dorsiflexed position


hallux limitus first-ray pathology characterized by restricted dorsiflexion (reduced sagittal-plane motion; i.e. <60° available dorsiflexion) at first metatarsophalangeal joint, during the propulsive phase of gait (Tables H3 and H4 and Box H2, Figure H2; see synovitis)




Table H3 Factors that predispose to hallux limitus/rigidus































Location Feature Characteristics
Intrinsic factors Foot shape Rectus foot
Long first toe
Long first metatarsal
  Biomechanical factors within the foot that cause excess STJ and MTPJ pronation, so that foot is pronated from midstance to toe off Ankle equinus
Pes planovalgus
Forefoot varus
Metatarsus primus elevatus
Hypermobile first ray
Flexor plate immobility
Plantar soft-tissue contracture
Functional hallux limitus
  Structural anomalies that predispose to excess STJ and MTPJ pronation External tibial torsion
Tibial varum
Knee position variants
Femoral retroversion
Longer limb
Wide-based gait
  Trauma Osteochondritis
Osteoarthrosis
Soft-tissue tears
Turf toe
Extrinsic factors Inflammatory joint disease Rheumatoid arthritis
Gout/crystal arthropathy
Psoriatic arthropathy
Generalized osteoarthritis
Sesamoid degeneration
  Occupational hazard – repeated forced dorsiflexion of the first MTPJ/stubbing the first toe Carpet laying
En pointe ballet dancing
Football
Netball
Tennis
High-heeled shoes

STJ, supratalar joint; MTPJ, metatarsophalangeal joint.


Table H4 Classification of stage of hallux limitus/rigidus


















Stage Characteristics
Stage 1
Functional HL
∼60° available dorsiflexion at 1 MTPJ
Functional (weight-bearing) limitation of dorsiflexion at 1 MTPJ, with:
• 1 MTPJ painful under load
• Hypermobility of first ray
• No real joint deterioration, but some osteophytosis
• Non-weight-bearing 1 MTPJ dorsiflexion near normal
Stage 2
Mild structural HL
35–55° available dorsiflexion at 1 MTPJ
Structural limitation of dorsiflexion at 1 MTPJ
• 1 MTPJ painful after exercise/movement
• Broadening and flattening of 1 MTPJ surfaces
• Narrowing of 1 MTPJ space
• Moderate osteophytosis of 1 MTPJ area
• Local bone sclerosis
• Elevation of the first ray
• Sesamoid hypertrophy
• Reduced 1 MTPJ dorsiflexion (weight- and non-weight-bearing)
• Reduced heel lift
• 1 MTPJ crepitus
Stage 3
Moderate structural HL
15–30° available dorsiflexion at 1 MTPJ
Structural loss of dorsiflexion at 1 MTPJ
• Pain within 1 MTPJ
• Marked 1 MTPJ deterioration
• Loss of 1 MTPJ space
• Extensive osteophytosis
• Bone sclerosis
• Cystic degeneration of subchondral bone
• Joint ‘mice’
• Hypertrophy of sesamoids
• Elevation of the first ray
• Loss of height of MLA
• Decreased calcaneal angle
• 1 MTPJ crepitus
• Marked reduction of heel lift
Stage 4
Severe HR
<15° available dorsiflexion at 1 MTPJ
1 MTPJ immobility
• 1 MTPJ ankylosis and loss of joint space
• Marked osteophytosis and increased bulk of 1 MTPJ
• Loss of heel lift and/or hyperextension of IPJ of hallux

1 MTPJ, first metatarsophalangeal joint; MLA, medial longitudinal arch; IPJ, interphalangeal joint.




hallux phalangeus valgus; hallux interphalangeus valgus transverse (or transverse + frontal-plane) deviation of the distal hallux phalanx, at the interphalangeal joint, towards the midline of the foot


hallux purchase the degree of contact achieved between the hallux pulp and the ground surface; a piece of paper should not move when attempting to pull it out from under the weight-bearing hallux pulp (Table H5)


Table H5 Classification of hallux purchase


















Grade Characteristics
Good The sheet of paper remains static and in situ when pulled
Fair The sheet of paper moves slightly when pulled, but tends to tear when greater traction is applied
Poor The sheet of paper can be pulled out with minimum effort
Absent The paper slips out easily; it is not retained by the hallux as the pulp of the toe does not make ground contact

Hallux purchase is inferred by the ease with which a sheet of paper can be pulled out from beneath the pulp of the weight-bearing hallux.


hallux rigidus ankylosis or grossly reduced sagittal-plane motion of first metatarsophalangeal joint (i.e. <5° available dorsiflexion); endpoint of progressive hallux limitus (Tables H3 and H4; Figure H3)



hallux valgus uniplanar, transverse-plane first-ray deformity in which the hallux tip is deviated away from the body midline, and the first metatarsal head deviated toward the body midline (Tables H3, H4 and H6); progression of minor hallux valgus may be slowed down or arrested by functional orthoses worn with appropriate shoe wear; surgery may be indicated to reduce major hallux valgus (Table H2)


Table H6 First-ray relationships that inform a diagnosis of hallux abductovalgus (from an anteroposterior-view radiograph)



































Angle Location Normal values
Intermetatarsal angle The angle between the longitudinal axes of the first and second metatarsals 8–12°
Metatarsus adductus angle The angle between the longitudinal axes of the lesser metatarsals and the first metatarsal <15°
Hallux abductus angle The angle between the longitudinal axes of the hallux and the first metatarsal <20°
Proximal articular set angle (PASA) The comparison of the planes of the articular surfaces of the head of the first metatarsal and the base of the proximal phalanx of the hallux <7.5°
Distal articular set angle (DASA) The comparison of the planes of the articular surfaces of the head of the proximal and the base of the distal phalanx of the hallux <7.5°
Hallux interphalangeus angle The angle between the longitudinal axes of the proximal and distal phalanges of the hallux <10°
Medial sesamoid position The relationship of the medial sesamoid and the head of the first metatarsal Within the medial groove of the first metatarsal head

hallux valgus angles Table H6


hallux varus transverse-plane first-ray deformity in which the hallux tip and first metatarsal head are both deviated towards the body midline


halo naevus melanocytic naevus surrounded by a characteristic ring of amelanotic skin


haloperidol central nervous system-acting drug used to minimize unwanted movement, e.g. tremor of drug-induced parkinsonism; and tic-like movement characteristic of choreas


hamamelis water; witch hazel cooling lotion extracted from witch hazel bark


hammer toe see toes, hammer


hamstrings the pair of tendons (from the large muscle mass on the back of the thigh) that form the upper medial and lateral boundaries of the popliteal fossa




hamstring tendinitis sports-related injury to hamstring muscle bellies, their tendons or insertions, characterized by tightness and pain in the affected muscle/tendon


hand disinfection; hand washing thorough hand cleansing (using antibacterial detergents and running water, followed by application of an alcoholic disinfectant preparation) to reduce resident flora and remove all traces of patient or fomite contact; the single most effective procedure to control spread of infections (e.g. meticillin-resistant Staphylococcus aureus [MRSA])


hand, foot and mouth disease; orf see disease, hand, foot and mouth


hangnail loose tag of epidermis attached at its proximal end within the medial or lateral nail fold


Hansen’s disease; leprosy see disease, Hansen’s (Tables H7 and H8)


Table H7 Presentations of Hansen’s disease (leprosy)





















Leprosy type Characteristics
Tuberculoid leprosy (TT) or paucibacillary leprosy (PB) Vigorous host resistance and low infection
A localized disease in patients with high cell-mediated immunity characterized by a single, clearly demarcated hypopigmented anaesthetic skin area of the face, hands or feet, with thickening of the subserving nerve
Borderline tuberculoid leprosy (BT) As TT, but more numerous, smaller skin lesions with thickening of peripheral nerves and deformity of the hands and feet
Borderline leprosy (BB) Numerous skin lesions of varying size and form (macules, papules, plaques) with punched-out, hypopigmented anaesthetic centres; widespread nerve involvement and limb deformity
Borderline lepromatous leprosy (BL) Large number of florid asymmetrical skin lesions of variable form, strongly positive to acid-fast bacilli
Lepromatous leprosy (LL) or multibacillary leprosy (MB) Severely compromised host resistance and massive infection Skin changes of the face, earlobes, buttocks, upper and lower limbs, peripheral oedema, rhinitis and loss of the outer one-third of the eyebrows are characteristic of the early stages, with later mucous membrane involvement causing nasal stuffiness, laryngitis and hoarseness, thence nasal septum perforation and collapse of the nasal cartilages (saddle-nose deformity), glove-and-stocking anaesthesia, gynaecomastia, testicular atrophy, ichthyosis, nerve palsies and neurotrophic resorption of the phalanges. Lucio’s phenomenon (endarteritis and ulceration) is noted in Mexico and Central America

Table H8 Lower-limb involvement in Hansen’s disease





















Disease effect Clinical symptoms
Sensory anaesthesia Painless trophic plantar ulceration along the lateral plantar border of the foot, of apical tissues, second metatarsophalangeal joint, pulp and interphalangeal joint area of the hallux
Motor paralysis Intrinsic muscle paralysis causing claw-toe formation and anterior drift of the plantar fat pad, with relative exposure of the plantar aspects of the metatarsophalangeal joints to abnormally high plantar pressures
Extrinsic muscle paralysis, i.e. paralysis of the anterior and peroneal muscles of the lower leg with footdrop and hindfoot inversion and the development of trophic ulcers along the lateral border of the foot
Autonomic neuropathy Loss of sweat gland function with dry skin and fissure
Compromised superficial and deep arterial circulation due to loss of control of arteriolar sphincters, so that, although the skin and superficial tissues are warm, skin perfusion is reduced and there is a greater than normal flow of blood through bone (bone hyperaemia) leading to osteoporosis, bone resorption and pathological fracture
Tarsal disintegration Infiltration of the foot bones with bacilli, causing rarefaction of cancellous bone, fracture of tarsal bones followed by profuse recalcification with loss of normal bony architecture
Hyperaemia-related osteoclastic resorption of bone
Osteoporosis and osteomyelitis Absorption of phalanges and pathological fractures of affected bones in neuropathic and immobile feet

hard corn see heloma durum (plural: helomata dura); see Table C14


hard exudates discrete, yellow-white lipid particles characteristic of background retinopathy with diabetic eye disease; hard exudates on the macula cause blindness


Harris and Beath mat rubber mat formed of intersecting squares with walls of varying heights, used to achieve a dynamic record of plantar pressures; the mat is inked and covered with a sheet of paper and the patient walks barefoot across the paper; areas of highest plantar pressure show as areas of increased density of ink when the paper is peeled off the mat (see Table G2)


Harris–Beath projection radiographic projection of the foot, to visualize rearfoot and tarsus; the patient is positioned with the foot flat to the support surface, ankle joint dorsiflexed and knees flexed (as if preparing for a standing jump); the X-ray beam is directed at the posterior aspect of the ankle joint, at an inclination angle of 35–45° (see Table R1)


Hatti pads form of antipronatory insole that limits rearfoot eversion, closely conforms to and supports the medial longitudinal arch, and improves first-ray function; used (in India) as part of the conservative treatment of insensate feet (due to Hansen’s disease)


hayfever allergic rhinitis; seasonal atopy triggered by pollens and dusts; may indicate hypersensitivity tendency


HbA1C see glycosylated haemoglobin


HBcAg hepatitis B virus core protein which indicates hepatitis B infectiousness (from a blood sample), but which disappears on recovery; HBcAg persisting for >6 months indicates hepatitis B carrier state


HC45 topical emollient cream containing 1% steroid; see corticosteroid


HDL see high-density lipoprotein cholesterol


HDN see haemolytic disease of the newborn


healing process of restoration of tissue integrity


healing agents topical agents promoting healing and healthy granulation


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Jun 12, 2017 | Posted by in ANATOMY | Comments Off on H

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