Fracture in children and limits of accecptability.pptx

Fracture in children and limits of accecptability

1. Remodelling in Children’s Fractures and Limits of Acceptability Dr. Kaushik Mondal Junior Resident Dept Of Orthopaedics SCB MCH

2. Introduction Bone remodelling in children → unique ability to correct deformity without surgical intervention Anatomic reduction less critical in children than adults Angulation correction following fracture reduction occurs maximally via physeal realignment (≈75%) + cortical drift (≈25%) Not seen universally but overestimation may cause permanent deformity Important for orthopaedic surgeons to know limits of acceptable deformity

3. Phases of Fracture Healing Inflammatory phase – hematoma, vascular response, cellular recruitment Reparative phase – cartilage + intramembranous bone formation, callus Remodelling phase – long process, driven by physiological stresses

4. Inflammatory Phase Begins immediately after fracture Hematoma formation → localized avascularity of the bone The vascular response give rise to cellular response TGF‑β released from the extracellular matrix of the bone stimulates mesenchymal precursors → osteoblasts, osteoclasts Fracture bridging occurs by subperiosteal bone formation and endo chondral bone formation at the endosteal areas. Motion at the fracture site leads to lower oxygen tension, which leads to more cartilage formation, which is ossified later. There is gradual revascularization of the dead bone at the fracture site.

5. Reparative Phase Highlighted by the formation of new blood vessels and the beginning of cartilage formation. Soft tissue provide vascular ingrowth to periosteal followed by endosteal areas As new bone forms under the periosteum, it is pushed away from the bone, making a collar of bone around the fracture. Primarily, this tissue is cartilaginous and fibrous and not very well ossified. Fracture unites clinically after the bony callus surrounds the fracture fragments and connects with the callus coming from the opposite side. At this point, the bone is clinically stable enough for the patient to begin extremity usage.

6. Remodelling Phase It may last for a short time in a young child or continue throughout the growth period or even beyond the cessation of growth in an older child. Occurs due to physiological stresses and strains. Osteoclasts or Osteoblasts are not responsible for remodelling, but coordinated bone resorption and bone formation over large regions around the fracture are responsible for it Unlike bone, cartilage healing lacks a remodelling phase Process corrects translation, axial angulation, minor rotation

7. Mechanisms of Translational Correction It is purely a periosteal correction and is dependent on the age of the patient. In children up to the age of 10–12, complete side-to-side displacement of entire shaft width can correct practically in the entire skeleton

8. Mechanisms of Angular Correction Wolff’s Law (1892) – stated that new bone is produced where it is necessary mechanically (in the weight-bearing area) and is reabsorbed from areas where it is not necessary. So angular correction occurs by new bone formation in concave areas, resorption in convex areas. Hueter-Volkmann Law (1862) – after a malunited fracture, adjacent physes tend to realign perpendicular to the forces acting through them, thus the growth plates realign perpendicular to load Physeal reorientation = ~75% correction; cortical drift = ~25%

9. Factors Affecting Remodelling Extremity involved (lower > upper) because of more mechanical load. Skeletal age (younger children <8yrs remodel better, because of more growth potential) Proximity to active growth plate/physis, because physis have more growth potential. Degree and orientation of the deformity—if the angulation lies in the plane of movement of the adjacent joint, the more substantial will be the remodeling .

10. Overgrowth Phenomenon Hyperaemia after fracture stimulates growth plate → increased bone length Most common after paediatric femur fractures; also tibia, humerus

11. Overgrowth – Femur Universal in <13 years; avg 0.92 cm, which was independent of age, fracture level, or position of fracture fragments at the time of healing. Overgrowth was most significant in the 3–9 year age group. Greatest in first 18 months post-fracture. Therefore shortening up to 1.5 cm acceptable in children of 2–11 years.

12. Overgrowth – Tibia & Humerus Tibia: ~5 mm avg in younger children, may have growth retardation in older age groups It is recommended not to accept any shortening in girls > 10 years and boys > 12 years, because of the growth retardation. It was noted that increased shortening at the time of the reduction, comminuted fractures, fracture at the proximal and distal end, and young children had higher overgrowth Humerus: Seen in majority, stops after ~18 months from fracture

13. Overgrowth – After Elastic Nailing Femoral overgrowth is a common finding in children treated with flexible nailing for femur shaft fractures. Most studies report mild overgrowth (<10 mm), though a small percentage show overgrowth >10 mm. The overgrowth tends to decrease over time, with long-term follow-up necessary to assess its true extent.

14. Rotational Malalignment Limited spontaneous correction in humans Small degrees tolerated (up to ~25° in femur) Tibial rotational deformities show no correction

15. Acceptability Criteria – Femur

16. Acceptability Criteria – Tibia

17. Acceptability Criteria – Proximal Humerus

18. Acceptability Criteria – Shaft of Humerus

19. Acceptability Criteria – Radius

20. Conclusions Remodelling is a unique healing ability in children allowing correction of malalignment, often avoiding the need for surgery. Side-to-side displacement (up to full shaft thickness) in children under 10 often remodels completely, primarily due to periosteal correction. Correction mechanisms: 75% by growth plate realignment (Hueter-Volkmann's law). 25% by cortical drift—new bone forms on the concave side, resorbed on the convex (Wolff’s law). Remodelling potential: Highest in neonates. More in lower limbs than upper. Greater near growing ends and along joint motion axes (e.g., elbow/knee). Rotational malalignment does not remodel well and must be corrected initially. Overgrowth : Common after femoral fractures but >1.5 cm shortening is unacceptable. Tibial fractures show minimal overgrowth; no shortening should be accepted. Use of age-wise acceptability criteria and visual aids helps in treatment decisions and counselling parents

21. References & Acknowledgments Remodelling in Children’s Fractures and Limits of Acceptability By Premal Naik Received: 9 October 2020 / Accepted: 20 November 2020 / Published online: 10 March 2021 © Indian Orthopaedics Association 2021