GROWTH PLATE - FINAL.pptx

Physis

1. PHYSIS: STRUCTURE & RELATED GROWTH DISORDERS Dr. Gokul Dev C JR 1, Dept. of Orthopaedics KMCT Medical College

2. STRUCTURE OF LONG BONE Diaphysis Epiphysis Metaphysis Articular Cartilage Periosteum Medullary Canal Endosteum

3. OSSIFICATION The natural process of bone formation In human embryo bone appears after 6-7th week Typically two distinct pathways in which bone forms INTRAMEMBRANOUS (cartilaginous intermediary absent) ENDOCHONDRAL ( cartilage model is first formed and which ossifies in latter process) Physiological : Callus formation and regenerate development Pathological : ectopic ossification and myositis ossificans

4. INTRAMEMBRANOUS OSSIFICATION

5. ENDOCHONDRAL OSSIFICATION

6. GROWTH PLATE / PHYSIS The remaining hyaline cartilage layer between the metaphysis and the epiphysis. At skeletal maturity - replaced with bone to form the epiphyseal scar Two growth plates exist at each end of immature long bones Regulates , helps and determines the length and shape of mature bone Last portion of the bone to ossify - vulnerable to fractures. Composed of cartilage cells arranged in well ordered long parallel columns

7. VASCULAR SUPPLY OF PHYSIS Epiphyseal arteries : supply blood via multiple branches , providing vascularisation of the proliferative zone Perichondrial arteries : supplies to the fibrous structure of growth plate. Nutrient artery : provides four – fifth of the metaphyseal blood supply Metaphyseal artery : the terminal branches of these vessels end in small vascular loops or capillary tufts below the last intact row of chondrocyte lacunae of growth plate

8. PHYSIS THREE COMPONENTS Cartilage Component Bony Component ( Metaphysis ) Fibrous perichondrial ring and ossification groove

9. MICROSCOPIC STRUCTURE

10. CARTILAGE COMPONENTS Reserve Zone ( Germinal / Resting Cartilage) Zone of Chondrocyte Proliferation Zone of Chondrocyte Hypertrophy Maturation Zone Degenerative Zone Zone of Provisional Calcification

11. RESERVE ZONE (RESTING/ GERMINAL ZONE)– Contains spherical, single or paired chondrocytes involved in matrix production. Lies immediate adjacent to epiphysis. Cells are not organized into columns. two main roles: matrix production and storage Ratio of extracellular matrix to cell volume is high . The epiphyseal arteries pass through this layer on their way to the proliferative zone Injury to this layer leads to cessation of growth.

12. ZONE OF CHONDROCYTE PROLIFERATION – Three purposes—matrix production, cellular proliferation and longitudinal growth. It has flattened chondrocytes arranged in distinct columns - only cells of growth plate that divide (proliferate). The epiphyseal arteries form terminating capillaries here The cells have a local feedback loop ( PTHrP , TGF-b, IHH ). Growth hormone exerts its effect here.

13. ZONE OF CHONDROCYTE HYPERTROPHY - Cells increase in size W eakest zone of the physis This zone has three discrete functional and histological zones Maturation Zone Degenerative Zone Zone of Provisional Calcification. The function of this zone is to prepare the matrix for calcification and to calcify the matrix. The lacunae that remain after apoptosis of hypertrophic chondrocytes are utilized by blood vessels.

14. Maturation zone: Chief function is to prepare the matrix for calcification. Chondrocytes enlarge to five to ten times Matrix is mainly composed of type II collagen and proteoglycan (most common Aggrecan ). Cell division ceases in this zone and calcium is accumulated in mitochondria

15. b) Degeneration zone: Role is further preparation of the matrix for calcification. Programmed cell death (apoptosis) of the chondrocytes ( non inflammatory). c) Zone of provisional calcification: Matrix vesicles , previously deposited into the extracellular matrix, release calcium into the zone of provisional calcification.

16. BONY COMPONENT ( METAPHYSIS) It is involved in vascular invasion of transverse The other functions are new bone formation and bone remodeling. It has two components The Primary Spongiosa - vascular invasion zone ( Woven bone is formed ) The Secondary Spongiosa ( remodelling of woven bone into lamaellar bone ) The external or anatomic remodeling gives funnel shape to metaphysis ( funnelization ).

17. FIBROUS PERICHONDRIAL RING AND OSSIFICATION GROOVE A fibrous sheath surrounds the growth plate at periphery, comprises of Perichondrial Ring Of Lacroix - provides mechanical support bone-cartilage junction of the growth plate. It is a dense fibrous band that encircles the growth plate at the bone-cartilage junction and in which collagen fibers run vertically, obliquely and circumferentially

18. The Ossification Groove Of Ranvier . contributes chondrocytes to the physis for the growth in diameter (appositional growth or latitudinal growth) of the plate. Three distinct cell groups: a. Progenitor cells for osteoblasts b. Undifferentiated cells c. Fibroblasts

19. PHYSIS ASSOCIATED DISEASES

20. DISORDERS OF RESERVE ZONE

21. GAUCHER’S DISEASE Most prevalent Lysosomal storage diseases Autosomal recessive Deficiency in glucocerebrosidase A ccumulation of glucosylceramide in lysosomes . “ Gaucher cells” in the bone marrow Orthopaedic Manifestations - bone pain (fracture, osteomyelitis ), joint pain or contracture, bone crisis ( osteonecrosis ), diffuse osteopenia 80% will develop deformities of the distal femur or proximal tibia - "Erlenmeyer Flask" appearance

22. TREATMENT : multidisciplinary approach (orthopedic , hematologic, and neurological abnormalities) ERLENMEYER FLASK APPEARANCE

23. DIASTROPHIC DWARPHISM (DIASTROPHIC DYSPLASIA) Rare congenital disorder ( autosomal recessive ). Mutations in the SLC26A2 gene. Defective type 2 collagen synthesis Normal development of cartilage and its conversion to bone lost. Clinical picture of short limb dwarphism .

24. CLINICAL FEATURES : Short stature ("twisted dwarf") Relatively normal trunk height Cleft palate (60%) Cauliflower ears (80%)  Hitchhikers thumb    Thoracolumbar scoliosis Severe cervical kyphosis   Hip and knee contractures Genu valgum Skewfoot (serpentine or Z foot) Tarsometatarsal adductus and valgus hindfoot Rigid clubfeet ( equinocavovarus )

25. TREATMENT : multidisciplinary approach to improve and maintain function. Surgical spinal instrumentation and fusion ( atlantoaxial instability, cervical myelopathy , or progressive scoliosis) Cauliflower Ears Hitchhikers Thumb   Cervical Kyphosis   Clubfeet Twisted Dwarf

26. PSEUDOACHONDROPLASIA Autosomal dominant. Similar to achondroplasia but without characteristic facial features Mutations in the cartilage oligomeric matrix protein (COMP) gene Defective processing and transport of proteoglycans results in abnormal protein build-up within the chondrocytes . E arly cell death of the chondrocytes short limb dwarfism.

27. CLINICAL FEATURES: Short trunk Rhizomelic or mesomelic shortness Waddling gait Ligamentous laxity Odontoid hypoplasia Scoliosis Platyspondyly Hip subluxation Varus or valgus knee (commonly windswept deformity).

28. RACHITIC-LIKE CHANGES

29. TREATMENT : Surgery if symptomatic atlantoaxial instability. Scoliosis is managed by bracing for curves between 25° and 45° Spinal fusion is indicated for larger curves. Femoral and iliac osteotomies often are needed for hip subluxation . Windswept knees are corrected with femoral and tibial osteotomies .

30. KNIEST’S SYNDROME / DYSPLASIA Autosomal dominant. Mutations in the COL2A1 gene, resulting in defective processing of proteoglycans

31. CLINICAL FEATURES: Short stature Disproportionate short-trunk dwarfism Joint stiffness / contractures Dumbell -shaped femur Hypoplastic pelvis and spine Scoliosis & kyphosis Early osteoarthritis Osteopenia Coxa vara Genu valgum

32. TREATMENT : Multidisciplinary (Orthopedic, Facial and Ocular abnormalities ). KNIEST HAND DUMBELL-SHAPED FEMUR

33. DISORDERS OF PROLIFERATIVE ZONE

34. HYPERPITUTARISM Due to Hypersecretion of GH due to acidophil adenoma. Causes excessive growth of entire skeleton in children & adolescents. GIGANTISM : when GH hypersecretion occurs before the fusion of the long bone epiphysis and is characterized by tall stature. ACROMEGALY : when GH hypersecretion occurs after the fusion of the epiphysis leading to large extremities and characteristic facies

35. ACROMEGALY GIGANTISM

36. Patient may develop deformity of hip due to epiphyseal displacement( epiphysiolysis ) Mental retardation, sexual immaturity TREATMENT - early surgical resection of tumour . - Somatostatin analogs - Radiation therapy

37. ACHONDROPLASIA The commonest form of abnormal short stature. About 1 in 25,000 births . Severe , disproportionate shortening of limb bones may be diagnosed by x-ray before birth. The main pathology lies in the abnormal endochondral longitudinal growth . Autosomal dominant : Point mutation in the gene coding for FGF receptor 3 (key role in endochondral cartilage growth). Adult height is usually around 125 cm in females and 132 cm in males

38. CLINICAL FEATURES Rhizomelic dwarfism    Proximal part of limb is shorter Macrocephaly Frontal bossing (broad forehead) Midface hypoplasia Bradydactyly (short digits)  Trident hands  Genu varum Thoracolumbar kyphosis   Foramen magnum stenosis

39. CHAMPAGNE GLASS PELVIS  TRIDENT HANDS INVERTED V IN DISTAL FEMUR PHYSIS

40. HYPOCHONDROPLASIA Very mild form of achondroplasia . 3.3 per 100,000 live births Short stature and noticeable lumbar lordosis . Head and face - not affected. Autosomal dominant X-RAY - slight pelvic flattening and thickening of long bones TREATMENT - Lower-limb lengthening surgery can be done in few cases with considerable chance of success.

41. MALNUTRITION Malnutrition or food restriction results in decreased cell proliferation in this proliferative zone of the physis. Deleterious effect of shorter bone length. Histological of physis: reduced chondrocytes per column in the proliferative zone.

42. IRRADIATION Irradiation in animal studies has been found to suppress cellular proliferation and cause disarray of cartilage cell T he proliferative zone is sensitive . Radiotherapy to treat childhood cancers can damage the proliferative zone

43. DISORDERS OF HYPERTROPHIC ZONE

44. TRAUMATIC INJURY Ligaments in children are functionally stronger than physis The physis is relatively weaker part of bone In children, over 30% of fractures may involve injury to the growth plate – most heal without any long term complication. M ay result in pre-mature ossification of the injured part & serious deformity of bone growth.

45. Salter-Harris Classification

46. Type 1 : occurs through physis only +/- displacement. GOOD prognosis Type 2 : have metaphyseal spike attached to the seperated epiphysis +/- displacement. MOST COMMON Type 3 : occurs through physis and epiphysis into the joint with joint inconguity (if displaced). POOR prognosis Type 4 : occurs in metaphysis and pass through physis and epiphysis into joint. Joint inconguity (if displaced). POOR prognosis Type 5 : usually diagnosed retrospect. Compression or crush fractures of physis. Cause permanent damage and growth arrest. WORST prognosis

47. TREATMENT : Displaced fractures should be reduced as soon as possible. Types 1 & 2 : usually be done closed (non- operatively) immobilization (cast/slab) for 3-6 weeks. Type 3 & 4 : ORIF, require perfect anatomical reduction as they may result in premature fusion/asymmetrical growth of bone end. Type 5 : ORIF, causes premature fusion and retardation of growth.

48. GROWTH ARREST Injury to the growth plate can result in a bridge of bone (or bar) forming across the cartilaginous physis. Premature growth arrest - lead to angular deformity of a limb or LLD. Bars may be peripheral, central or linear. Complete growth arrest - shortening . Partial arrest - angular deformity. GROWTH ARREST LINES

49. TREATMENT: Bony bridge is mapped out with MRI or CT scanning to ascertain the precise size and location. i ) Resection of the bar with the interposition of fat Ii) Epiphysiodesis to complete the arrest of the physis. If there is limb length discrepancy – further treatment i ) To manage the length discrepancy conservatively Ii) Contralateral epiphysiodesis Iii) Ipsilateral lengthening of the affected bone.

50. A bar of over 50% is not suitable for resection. If bar is less than 50%, resection can be considered with the Lagenskiold technique. This involves the removal of the bar via a tunnel through a metaphyseal window and the interposition of fat. The fat is to prevent reformation of the bony bridge.

51. HEREDITARY MULTIPLE EXOSTOSIS (DISPHYSEAL ACLASIS) The most common and least disfiguring of all the skeletal dysplasias . The underlying fault is unrestrained transverse growth of the physeal plate. Autosomal dominant disorder. Mutations are seen on the chromosomes 8, 11 and 19 . Results in benign chondrogenic bone tumours growing from the metaphysis towards the diaphysis

52. X-RAY i ) poorly modelled , broadened metaphysis , with sessile or pedunculated exostoses arising from the cortices. ii) Bony mottled appearance around a bony excrescence indicates calcification in the cartilage cap iii) The distal end of ulna is sometimes tapered or carrot shaped and reduced in length iv) the radius is usually bowed and this discrepancy may lead to sub- laxation of radiohumeral joint.

53. TREATMENT: Conservative Management if no symptoms If the deformities of forearms or legs is so severe and functionally limiting : Osteotomy it should be postponed till late adolescence.

54. MUCOPOLYSACCHARIDOSES Proteoglycan’s - major component in bone matrix, cartilage, Inter-vertebral discs and synovium . Defective proteoglycan’s are degraded by lysosomal enzymes. If these enzymes deficient - accumulation of PG’S & irregular bone matrix. All except Hunter's syndrome (an X-linked recessive disorder) are transmitted as autosomal recessive.

55. Orthopaedic Manifestations: Hip dysplasia Carpal tunnel syndrome Trigger finger Coarse facies Craniocervical pathology Genu valgum X-RAY : Bone dysplasia affecting the vertebral bodies, epiphyses and metaphysis , typically bones have a spatulate pattern.

56. RICKETS Characterized by softening and weaking of bones with defective mineralization of bone matrix which is seen histologically as excessive unmineralized osteoid . it occurs before closure of growth plate so that abnormalities of skeletal growth are super-imposed. AETIOLOGY- 1. Deficiency of vitamin D, calcium and phosphate 2. Malabsorption 3. Renal diseases (renal losses, distal RTA, CRF etc).

57. TYPES OF RICKETS Nutritional rickets or vitamin D deficiency rickets. Vitamin D dependent rickets: type 1 & type 2 Vitamin D resistant rickets (Familial hypophosphataemia ). Secondary rickets : CLD, End stage renal diseases (CKD) etc.

58. CLINICAL FEATURES Large head, open fontanelles and craniotabes (frontal bossing) Narrow chest / Pegion chest Beaded ribs- the rickety rosary Prominent abdomen. Bowing of long bones with genu valgum / varum Delayed dentition with irregular, soft decaying teeth Pale skin, flabby subcutaneous tissue, typical wizened look.

59. RADIOLOGICAL APPEARANCES “CUPPING, SPLAYING, FRAYING” Acute Stage - Normal rounded appearance of epiphysis is replaced by a cloudy area containing one or more indistinct centres of ossification. Second Stage - Epiphysis appears as a mottled irregular, ill- defined shadow and broadened. The metaphysis is ragged but is now broader than normal. Third Stage - The shadow becomes denser and at the end of metaphysis a dense line appears. Fourth stage - The characteristic increase in breadth of metaphysis is still present, but the bone is now clearly defined & shows normal content of calcium salts.

60. TREATMENT Medical : Diet and supplementation Prevention of deformity - child’s movements should be controlled. In difficult children it is often advisable to fit ‘rickets’ splints. 3. Treatment of existing deformity- Deformity is usually corrected by splints or by osteotomy .

61. SLIPPED CAPITAL FEMORAL EPIPHYSIS Slipped upper femoral epiphysis (SUFE) or slipped capital femoral epiphysis (SCFE ) 10 per 100,000 most common disorder affecting adolescent hips left hip - more common shearing force - results in a fault line that propagates along the capital physis and eventually results in the slip. Hormonal balance also plays a role.

62. Grade I - 0-33 % of slippage Grade II - 34-50 % of slippage Grade III - >50 % of slippage LODER CLASSIFICATION Stable : Able to bear weight with or without crutches, Minimal risk of osteonecrosis (<10%) Unstable : Unable to ambulate (not even with crutches), High risk of osteonecrosis (24-47 %)

63. TRETHOWAN’S SIGN KLEIN’S LINE ‘S’ SIGN

64. TREATMENT : Percutaneous in situ fixation. One vs. Two cannulated screws Capsulotomy Contralateral pinning - in patients at high risk, (initial slip at age < 10, obese males, endocrine disorders, those with open triradiate cartilage). Open epiphyseal reduction and fixation Osteochondroplasty Proximal femoral osteotomy

65. DISORDERS OF THE METAPHYSIS

66. METAPHYSEAL CHONDRODYSPLASIAS (PYLE’S DISEASE) R are genetic skeletal dysplasia Consisting of Jansen and Schmid types in which cells of the hypertrophic zone extend into the metaphysis

67. INFECTIONS OSTEOMYELITIS An acute or chronic inflammatory process involving the bone and its structures secondary to infection with pyogenic organisms, including bacteria, fungi, and mycobacteria . Common in children – Acute hematogenous Organisms usually settle in metaphysis Most often in proximal tibia or at proximal/distal femur. Most common organism : Staphylococcus aureus (70 %) Under 4 years : Haemophilus influenza

68. Hematogenous Osteomyelitis In Ends Of Bone Near the transverse septa separating metaphyseal from cartilage component there is low oxygen tension high degree of rouleaux formation of RBCs due to vascular stasis. High levels of phosphoglucoisomerase (enzyme compatible with anaerobic metabolism) The low oxygen tension inhibits WBC activity which is highly oxygen dependent - favorable for pathogens.

69. CLINICAL FEATURES: Severe pain (throbbing) Fever malaise Loss of function toxaemia in neglected cases. Metaphyseal tenderness resistance to joint movement Soft tissue abscess

70. DIAGNOSIS X RAY : Faint extra-cortical outline due to periosteal new bone formation (classical sign of pyogenic OM ). USG-may detect a sub- periosteal collection of fluid in the early stages of osteomyelitis . Radioscintigraphy with 9gTc-HDP. MRI can distinguish soft tissue infection from osteomyelitis - Typical feature is a reduced intensity signal in T2- weighted images. Aspiration of pus from the metaphyseal sub- periosteal abscess or adjacent joint.

71. TREATMENT Supportive treatment for pain and hydration Splintage of affected part Antibiotic therapy Surgical drainage. COMPLICATIONS Altered bone growth in infants, physeal damage may lead to arrest of growth and shortening of bone. In older children - the bone occasionally grows too long because metaphyseal hyperaemia stimuate the growth disc.

72. OSTEOPETROSIS (ALBERS-SHONBERT DISEASE) R are metabolic disease due to abnormal resorption of immature bone defective osteoclastic activity. The result is dense bone which is prone to fracture. Osteopetrosis - ‘stone bone’ , marble bone disease. X-rays : loss of the medullary canals and dense bone.

73. RUGGER JERSEY SPINE BONE-IN-BONE APPEARANCE

74. OSTEOGENESIS IMPERFECTA BRITTLE BONE DISEASE There are multiple forms, with variable clinical pictures and differing modes of inheritance. M ost common genetic mutations - COL 1A1 and COL 1A2 genes. Reduced type 1 collagen production thus brittle bones - multiple fractures and deformities (such as tibial bowing).

75. BLUE SCLERA

76. SCURVY Vitamin C (ascorbic acid) deficiency. Vitamin C is needed for the hydroxylation of proline (vital step for the formation of collagen). Deficiency leads to fragile capillaries, bleeding gums and bone pain. The secondary spongiosa of the metaphysis is most affected. X-RAY : the ‘white line of Frankel’ or ‘Frankel line’ located at the metaphysis , as increased density zone of provisional calcification.

77. LAWS OF THE PHYSIS Hueter -Volkmann law: ‘Increased compression at the growth plate slows longitudinal growth.’ Delpeche’s law: ‘Increasing tension on the growth plate speeds growth . Wolff’s law: ‘Bone adapts according to loads under which it is placed.’

78. References Apley’s system of orthopaedics & fractures Tenth edition Campbell's Operative Orthopaedics - 14th Edition Handbook of Fractures 6th Edition 2019 By Kenneth Egol , Kenneth J. Koval & Joseph Zuckerman Essential Orthopedics Principles & Practice by Manish Kumar Varshney The growth plate: anatomy and disorders Thomas Voller Paul Cameron etal .

79. THANK YOU