Fracture healing is a complex process that begins immediately after a bone is broken and continues for many years as the bone remodels. It involves the formation of a soft callus that is later replaced by hard bony callus as new bone bridges the fracture gap. The type and amount of new bone formed depends on factors like fracture type, stability, and biological environment. Fracture healing progresses through inflammatory, callus formation, consolidation, and remodeling stages. Complications can include malunion, delayed union, and nonunion, which are influenced by injury, patient, tissue, and treatment factors and require specific management approaches.

1. FRACTURE HEALING Dr. NISHITH SHARMA DEPT. OF ORTHOPAEDICS NIMS MEDICAL COLLEGE & HOSPITAL

2. INTRODUCTION Fracture is a break in the structural continuity of bone or periosteum. The healing of fracture is in many ways similiar to the healing in soft tissue wounds except that the end result is mineralised mesenchymal tissue i.e. BONE. Fracture healing starts as soon as bone breaks and continues modelling for many years.

3. The essential event in fracture healing is the creation of a bony bridge between the two fragments which can be readily be built upon and modified to suit the particular functional demands .

5. Periosteum

6. Bone marrow

8. INTRAMEMBERANOUS OSSIFICATION

9. OPPOSITIONAL NEW BONE FORMATION

10. OSTEONAL MIGRATION (Creeping Subsitituion)

12. GAP CONDITION

13. FIXATION RIGIDITY

14. LOADING

17. INFLAMATION AND CELLULAR PROLIFERATION

18. STAGE OF CALLUS FORMATION

19. STAGE OF COSOLIDATION

21. Tissue destruction and Hematoma formation

22. INFLAMATION AND CELLULAR PROLIFERATION Within 8 hours inflammatory reaction starts. Proliferation and Differntiation of mesenchymal stem cells. Secretion of TGF-B , PDGF and various BMP factors.

23. Callus Formation Fibrocartilaginous callus forms Granulation tissue (soft callus) forms a few days after the fracture Capillaries grow into the tissue and phagocytic cells begin cleaning debris

24. Callus Formation Theory OSTEOPROGENITOR CELL present in all ENDOSTEAL and SUBPERIOSTEAL surface give rise to CALLUS. CALLUS arises from NON-SPECIALISED CONNECTIVE TISSUE CELLS in the region of fracture which are induced into conversion to OSTEOBLASTS.

25. Callus Formation

26. STAGE OF CONSOLIDATION New bone trabeculae appear in the fibrocartilaginous callus Fibrocartilaginous callus converts into a bony (hard) callus Bone callus begins 3-4 weeks after injury, and continues until firm union is formed 2-3 months later

29. A: Roentgenogram of a callus healing in a sheep tibia with the osteotomy line still visible (6 weeks p.o.). B: Histological picture of a sheep tibia osteotomy (fracture model) after bone bridging by external and intramedullary callus formation. A few areas of fibrocartilage remain at the level of the former fracture line (dark areas).

31. Delaying formation repair tissue

33. Joint stiffness*Segmental fractures *Soft tissue interposition * Damage to the blood supply

35. NUTRTION

36. HEALING PROCESS NEEDS Energy Proteins & carbohydrates

38. Growth hormone

39. Thyroid hormone

40. Calcitonin

41. Insulin

42. Anabolic steroids

43. DM

44. Hypervitaminosis D

47. Bone necrosis

49. Osteomalacia

50. Primary malignant bone tumors

51. Metastatic bone tumors

52. Fibrous dysplacia

53. Benign bone tumors

54. Bone cysts

55. Osteogenesisimperfecta

56. Paget’s disease

59. Traction

60. Cast Imm

61. Ext.Fixation

62. Int.FixationFacilitate fracture healing by Preventing repeated disruption of Repair tissue

63. COMPLICATIONS OF FRACTURE HEALING MALUNION DELAYED UNION NONUNION

64. MAL UNION A MALUNITED Fracture is one that has healed with the fragments in a non anatomical position. CAUSES 1INACCURATE REDUCTION 2 INEFFECTIVE IMMOBILIZATION

66. ROTATION or ANGULATION

67. OVERRIDING

69. ROTATION

70. RESTORATION OF NORMAL LENGTH

71. ACTUAL POSITION OF FRAGMENTS (LEAST IMPORTANT)

72. ANALYSIS OF DEFORMITY RIES and O’NEILLdeveloped TRIGNOMETRIC ANALYSIS of DEFORMITY and designed E-GRAPH to determine the true maximal deformity on AP and LATERAL X-Ray views.

74. SOFT TISSUE

76. ROTATION

78. Delayed Union cont. If still nonunited a decision should be made to treat the fracture as nonunion External ultrasound or electrical stimulation may be considered Surgical treatment should be carried out to remove interposed soft tissues and to oppose widely separated fragments Iliac grafts should be used if plates and screws are placed but grafts are not usually needed when using intramedullary nailing, unless reduction is done open

79. Nonunion FDA defined nonunion as “established when a minimum of 9 months has elapsed since fracture with no visible progressive signs of healing for 3 months” Every fracture has its own timetable (ie long bone shaft fracture 6 months, femoral neck fracture 3 months)

80. Delayed/Nonunion Factors contributing to development: Systemic Local

81. Delayed/Nonunion cont. Systemic factors: Metabolic Nutritional status General health Activity level Tobacco and alcohol use

82. Delayed/Nonunion cont. Local factors Open Infected Segmental (impaired blood supply) Comminuted Insecurely fixed Immobilized for an insufficient time Treated by ill-advised open reduction Distracted by (traction/plate and screws) Irradiated bone Delayed weight-bearing > 6 weeks Soft tissue injury > method of initial treatment

83. Nonunion cont. Nonunited fractures form two types of pseudoarthrosis: Hypervascular or hypertrophic Avascular or atrophic

84. Nonunion cont. Hypervascular or Hypertrophic: Elephant foot (hypertophic, rich in callus) Horse foot (mildly hypertophic, poor in callus) Oligotrophic (not hypertrophic, no callus) Hypervascular nonunions. A, "Elephant foot" nonunion. B, "Horse hoof" nonunion. C, Oligotrophic nonunion (see text). (Redrawn from Weber BG, Cech O, eds: Pseudarthrosis, Bern, Switzerland, 1976, Hans Huber.)

85. Nonunion cont. Vascular or Atrophic Torsion wedge (intermediate fragment) Comminuted (necrotic intermediate fragment) Defect (loss of fragment of the diathesis) Atrophic (scar tissue with no estrogenic potential is replacing the missing fragment) Avascular nonunions. A, Torsion wedge nonunion. B, Comminuted nonunion. C, Defect nonunion. D, Atrophic nonunion (see text). (Redrawn from Weber BG, Cech O, eds: Pseudarthrosis, Bern, Switzerland, 1976, Hans Huber.)

86. Nonunion cont. Classification (Paley et al) Type A<2cm of bone loss A1 (Mobile deformity) A2 (fixed deformity) A2-1 stiff w/o deformity A2-2 stiff w/ fixed deformity Type B>2cm of bone loss B1 with bony defect B2 loss of bone length B3 both A, Type A nonunions (less than 1 cm of bone loss): A1, lax (mobile); A2, stiff (nonmobile) (not shown); A2-1, no deformity; A2-2, fixed deformity. B, Type B nonunions (more than 1 cm of bone loss): B1, bony defect, no shortening; B2, shortening, no bony defect; B3, bony defect and shortening.

87. Nonunion cont. Treatment: Elecrical Electromagnatic Ulrasound External fixation (ie deformity, infection, bone loss) Surgical Hypertrophic: stable fixation of fragments Atrophic: decortication and bone grafting According to classification: type A : restoration of alignment, compression type B : cortical osteotomy, bone transport or lengthening

88. Nonunion cont. Surgical guidelines: Good reduction Bone grafting Firm stabilization

89. Nonunion cont. Reduction of the fragments: Extensive dissection is undesirable, leaving periosteum, callus, and fibrous tissue to preserve vascularity and stability, resecting only the scar tissue and the rounded ends of the bones External fixator, Intramedullary nailing, Ilizarov frame

90. Nonunion cont. Bone Grafting origins: Autogenous “the golden standard” Allograft Synthetic substitute

91. Nonunion cont. Bone grafting techniques: Onlay Dual onlay Cancellous insert Massive sliding graft Whole fibular transplant Vascularized free fibular graft Intamedullary fibular graft

92. BONE GRAFTING contd…. CRITERTIA FOR SUCCESSFUL BONE GRAFT OSTEOCONDUCTION OSTEOGENICITY OSTEOINDUCTION

93. Nonunion of tibial shaft treated by dual onlay grafts Dual onlay

94. Massive sliding graft GILL MASSIVE SLIDING GRAFT

95. Whole fibular transplant Bridging of bone defect with whole fibular transplant. A, Defect in radius was caused by shotgun wound. B and C, Ten months after defect was spanned by whole fibular transplant, patient had 25% range of motion in wrist, 50% pronation and supination, and 80% use of fingers.

96. Vascularized free fibular graft Posteroanterior and lateral roentgenograms made 3 years after fibular transfer, showing excellent remodeling with fracture healing. (From Duffy GP, Wood MB, Rock MG, Sim FH: J Bone Joint Surg 82A:544, 2000

97. Intamedullary fibular graft Anteroposterior roentgenogram of humerus 5 months after insertion of fibular allograft and compression plating with a 4.5-mm dynamic compression plate revealing evidence of bridging callus formation and incorporation of the allograft. (From Crosby LA, Norris BL, Dao KD, McGuire MH: Am J Orthop 29:45, 2000.)

98. Nonunion cont. Stabilization of bone fragments: Internal fixation (hypertrophic #): intamedullary, or plates and screws External fixation(defects associated#): ie Ilizarov

99. Internal fixation Roentgenograms of patient with subtrochanteric nonunion for 22 years treated with locked second generation femoral nail. A, Preoperatively. B, Postoperatively.

100. Ilizarov Monofocal osteosynthesis with Ilizarov fixator for hypertrophic nonunions with minimal infection, as recommended by Catagni Bifocal osteosynthesis with Ilizarov fixator after debridement of necrotic segments, as recommended by Catagni.

101. Ilizarov cont. Type IIIB open tibial fracture in 30-year-old man struck by automobile. Initial treatment was with four-pin anterior half-pin external fixator that was later converted to six-pin fixator; this fixator was removed because of persistent infection. B, One year after injury, infected nonunion with deformity. C, Shape of tibial deformity is duplicated by Ilizarov frame and is gradually corrected as nonunion is compressed. D, Union obtained at 4½ months.

102. Nonunion cont. Factors complicating nonunion Infection Poor tissue quality Short periarticular fragments Significant deformity

103. Infection management Treatment of nonunion of tibia in which sequestration or gross infection is present. A, Bone is approached anteriorly and is saucerized, incision is closed, and infection is treated with antibiotics by irrigation and suction. B and C, Tibia is grafted posteriorly. B, Skin incision. C, Tibia and fibula have both been approached posterolaterally. Posterior aspect of tibia (or tibia and fibula) is roughened and grafted with autogenous iliac bone

104. Nonunion cont. Specific Bones Metatarsals Tibia Fibula Patella Femur Pelvis and acetabulum Clavicle Humerus Radius Ulna

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