Physeal injuries

growth plate injuries, paediatric orthopaedics

1. PHYSEAL INJURIES CHETAN

2. Bone growth is achieved by adding newly synthesized bone to existing bone by two mechanisms: E ndochondral ossification I ntramembranous ossification Bone growth

3. bone forms via a cartilaginous intermediate physis best reflects this process From 9 to 10 weeks' gestational age to skeletal maturity at 15 to 17 years, they are responsible for the longitudinal growth of bone Endochondral ossification

4. Physeal injuries represent 15% to 30% of all fractures in children. The incidence varies with age and has been reported to peak in adolescents . Physeal injuries involving the phalanges account for over 30% of all physeal fractures (wrist jt more common)

5. Growth hormone increases the number of cells in the physeal columns; Thyroid hormone potentiates cytoplasmic proliferation ; Oestrogens play an important role in triggering physeal closure. Hormonal effects upon skeletal growth

6. zones / resting zone

7. Epiphyaseal vessels—supply germinal layer Metaphyseal vessels—supply central ¾ of physis Periosteal physis —supply peripheral Types of epiphysis Pressure epiphysis Traction Atavistic aberrant Blood supply of physis

8. The first two zones have an abundant extracellular matrix and, consequently, a great deal of mechanical integrity, particularly in response to shear forces. The third layer, the hypertrophic zone, contains scant extracellular matrix and is weaker. On the metaphyseal side of the hypertrophic zone there is an area of provisional calcification leading to the zone of enchondral ossification. The calcification in these areas provides additional resistance to shear. Thus, the area of the hypertrophic zone just above the area of provisional calcification is the weakest area of the physis, and it is here that most injuries to the physis occur

9. It is a wedge-shaped group of germinal cells that is continuous with the physis  The zone of Ranvier consists of three cell types— Osteoblasts form the bony portion of the perichondral ring at the metaphysis; chondrocytes contribute to latitudinal growth ; fibroblasts circumscribe the zone and anchor it to perichondrium above and below the growth plate . Zone of R anvier

10. It is a fibrous structure that is continuous with the fibroblasts of the zone of Ranvier and the periosteum of the metaphysis . It provides strong mechanical support for the bone–cartilage junction of the growth plate Perichondrial Ring (LaCroix)

11. Epiphyseal blood supply by Dale and Harris T ype A , T he epiphysis is nearly entirely covered by articular cartilage. Consequently , the blood supply traverses the metaphysis and may be damaged on separation of the metaphysis and epiphysis . T ype B , T he epiphysis is only partially covered by articular cartilage . Because the blood supply enters through the epiphysis, separation of the metaphysis and epiphysis will not compromise the blood supply to the germinal layer Proximal femur Proximal humerus Distal femur Proximal & distal tibia Distal radius

12. The most frequent mechanism of injury is fracture M C, fracture injury is direct, with the fracture pattern involving the physis itself. Occasionally, physeal injury from trauma is indirect and associated with a fracture elsewhere in the limb segment, either as a result of ischemia or perhaps compression infection, disruption by tumour, cysts, tumour-like disorders, vascular insult, repetitive stress , irradiation , and other rare etiologies Etiology

13. Long bone osteomyelitis or septic arthritis (particularly of theshoulder , hip, and knee) can cause physeal damage resulting in either physeal growth disturbance or frank growth arrest

14. Partial or complete growth arrests can occur from a pure vascular injury to an extremity. Salter–Harris type V injuries; the most common location for this is the tibial tubercle after femoral shaft or distal femoral physeal fractures Vascular Insult

15. EPIDEMIOLOGY SH2 MC PHALNGES 44%, DISTAL RADIUS 18%,DISTAL TIBIA11% MALE:FEMALE -2:1- 14YEARS:12YEARS occurred twice as often in the upper extremities as in the lower extremities.

16. Salter and harris Based on the Radiographic appearance of fracture. The first three types were adopted from Poland (types I, II, and III) and Aitken (Aitken type III became Salter-Harris type IV ) The higher the classification the more likely Is physeal arrest or joint incongurity to occur

17. Is a separation of the epiphysis from the metaphysis occurring entirely through the physis . It usually occurs in the zone of hypertrophy (weakest) It is rare and seen most frequently in infants or in pathologic fractures, such as those secondary to rickets or scurvy. Because the germinal layer remains with the epiphysis, growth is not disturbed unless the blood supply is interrupted, as frequently occurs with traumatic separation of the proximal femoral epiphysis. Phalenges Metacarpals

18. Radiographs of undisplaced type I physeal fractures, are normal except for associated soft tissue swelling. type I fractures occurred most frequently in the phalanges, metacarpals, distal tibia, and distal ulna. Epiphyseal separations in infants occur most commonlyin the proximal humerus , distal humerus , and proximal femur Ultrasound is particularly helpful for assessing epiphyseal separations in infants (especially in the proximal femur and elbow regions) without the need for sedation

19. The fracture extends along the hypertrophic zone of the physis and at some point exits through the metaphysis. The epiphyseal fragment contains the entire germinal layer as well as a metaphyseal fragment of varying size. This fragment is known as Thurston Holland's sign . The periosteum on the side of the metaphyseal fragment is intact and provides stability once the fracture is reduced. Growth disturbance is rare because the germinal layer remains intact. distal radius

20. B y def :- they cross the germinal layer and are usually intra-articular . O ften ass with high-energy or compression mechanisms of injury, which imply greater potential disruption of the physis & higher risk of subsequent growth disturbance Consequently , if displaced, they require an anatomic reduction, which may need to be achieved open Tillaux # distal humerus

21. Salter–Harris type III fractures begin in the epiphysis as a fracture through the articular surface and extend vertically toward the physis . The fracture then courses peripherally through the physis . The articular surface is involved and the fracture line involves the germinal and proliferative layers of the physis .

22. Vertical shear # Extend from the metaphysis across the physis and into the epiphysis . Thus , the # crosses the germinal layer of the  physis and usually extends into the joint. (articular) This # pattern is frequent around the medial malleolus , Lateral condylar fractures of the distal humerus ( milch type 1) and intra-articular two-part triplane fractures of the distal tibia with displacement, may result in metaphyseal–epiphyseal cross union there by causing growh disurbance treatment principles include obtaining anatomic reduction and adequate stabilization to restore the articular surface and prevent metaphyseal–epiphyseal cross union

23. Is a crushing injury to the physis from a pure compression force . Those authors who have reported type V injuries have noted a poor prognosis, with almost universal growth disturbance Eg :- Of such an injury is closure of the tibial tubercle, often with the development of recurvatum deformity of the proximal tibia, after fractures of the femur or distal femoral epiphysis unrecognized on initial radiographs. Undoubtedly, more sophisticated imaging of injured extremities (such as with MRI) will identify physeal injuries in the presence of normal plain radiographs

24. Injury to the perichondrial ring Type 6 injury RANG

25. Trauma to epiphysis ( chondral to osteochondral ) Isolated injury of the epiphyseal plate Type 7 ogden

26. # of metaphysis Isolated injury of the metaphysis with possible impairement of enchondral ossification Type 8

27. Avulsion injury to periosteum which may impair intramembranous ossification Type 9

28. The higher the classification , the more likely is physeal arrest or joint incongruity to occur.

29. Peterson

30. Type I is a fracture of the metaphysis extending to the physis . Types II to V are the equivalents of Salter-Harris types I, II, III, and IV, respectively. Peterson type VI is epiphyseal (and usually articular surface) loss. Lawnmower injuries are a frequent mechanism for type VI injuries

31. PETERSON 1 # METAPHYSIS EXTENDING INTO PHYSIS P 2 META + PHYSIS P 2 PHYSIS P4 EPI+ PHYSIS P5 META+EPI+ PHYSIS P6 PHYSIS MISSING SH2 SH1 SH3 SH4 POLAND 2 PO1 PO3,4 AITKEN 1 A2 A3

32. Salter-Harris I fracture of the distal femur. (widening)

33. Displaced Salter-Harris II fracture of the distal femur (with the Thurstan Holland fragment)

34. Salter-Harris II fracture of the distal tibial epiphysis

35. CT scan -Salter-Harris III fracture of distal anterolateral tibial epiphysis ( ie , Tillaux fracture).

36. Displaced Salter-Harris IV fracture of the proximal tibia The lateral portion of the epiphysis and the medial portion of the epiphysis are independently displaced

37. initial injury radiograph of ankle subjected to significant compressive and inversion forces. minimally displaced fractures of tibia and fibula with apparent maintenance of distal tibial physeal architecture.

38. Follow-up radiograph - growth arrest secondary to Salter-Harris V injury. Note the markedly asymmetric Park-Harris growth recovery line, indicating that the lateral portion of the growth plate continues to function and the medial portion does not.

39. Mortise radiograph -The Salter-Harris VI pattern. In this case, the radiograph indicates that it is quite likely that a small portion of the peripheral medial physis (as well as a small amount of adjacent epiphyseal and metaphyseal bone) has been avulsed

40. Growth plate (physeal) fractures. Radiographic evidence of a pediatric stubbed great toe.

41. Xray of the injured limb in atleast 2 views Classification of injury types usually done by radiograph Ct scans may clarify complex # patterns Mri may show considerably more physeal damage

42. Treatment

43. Generally all type 1 and type 2 # do well with closed reduction All type 3 &4 # should be treated by ORIF regardless of the amount of displacement In type V fractures , the cartilage cells of the physis are crushed , and regardless of the form of treatment, growth disturbance can occur . A type V fracture usually is diagnosed only in retrospect when a growth disturbance develops

44. General principles of Rx Most SH I and II injuries can be treated with closed reduction and casting or splinting and then reexamination in 7-10 days to evaluate maintenance of the reduction . Displaced injuries:- require reduction (within 48 hours) because growth arrest is common after late reduction.

45. Greater angular deformity can be tolerated in the upper extremity than in the lower extremity, More valgus deformity can be tolerated than varus , More flexion deformity can be tolerated than extension .

46. More proximal deformities of the lower extremity (in the hip) are better compensated for than distal deformities (the knee and, least of all, the ankle). Spontaneous correction of angular deformities is greatest when the asymmetry is in the plane of flexion or extension ( ie , the plane of joint motion), F unction often returns to normal unless the fracture occurs near the end of growth.

47. younger the patient ,:- more remodeling potential, greater degrees of displacement are acceptable. But have greater potential for deformity. A growth plate that requires higher energy to cause failure tends to have a higher rate of growth arrest. For instance, the distal femoral and proximal tibial

48. ( SH III and IV)- require ORIF. Smooth pins should parallel physis in epiphysis or metaphysis, avoid physis. Oblique application of pins across physis considered only when satisfactory internal fixation is unattainable with transverse fixation. Type V fractures - rarely diagnosed acutely, treatment often delayed until formation of a bony bar across physis. A high level of clinical suspicion is necessary

49. Correct placement of cannulated screws across epiphysis and metaphysis

50. Crossing the physis with any form of fixation should be avoided if possible In type III and IV fractures the pins should cross the epiphysis in the fractured areas In type II and IV fractures they should cross the metaphysis and epiphysis rather than the physis if possible. Small cannulated screws are well suited for these fractures.

51. COMPLICATIONS 1)Growth acceleration first 6-18 months after injury. increased vascular response. use of fixation devices that may stimulate longitudinal growth. Treatment in adolescents may involve an epiphysiodesis . If more than 6 cm of correction is desired- lengthening procedures for bilateral limb-length equilibration.

52. 2) Growth arrest Premature partial growth arrest is far more common and can appear as peripheral or central closures. Complete growth arrest is uncommon. angular deformities and limb-length discrepancies. Peripheral arrests are produced when (bone bar/bridge) forms, connecting metaphysis to epiphysis, traversing the physis. If bar is located medially, the normal physis continues to grow laterally, producing a varus deformity. Anterior bone bars - recurvatum deformity.

53. Central growth arrests - tented lesions of physis and epiphysis due to a central osseous tether with metaphysis, resulting in physeal coning. Some longitudinal growth continues in patients with growth retardation, though at a much slower rate; thus, a progressive shortening of the limb occurs. Partial growth arrests may be visible on radiographs as early as 3-4 months postinjury or may be delayed as long as 18-24 months. Follow-up checks may be necessary for 1-2 years postinjury to monitor physeal healing and growth response.