Delayed Unions and Nonunion

Presentation on delayed union and nonunion of fracture for orthopaedics resident and mbbs students

1. DELAYED UNION AND NON-UNION Presenter : DR. BiJAY Mehta Moderator : DR. KIRAN KHANAL

2. CONTENTS Definition Etiology Classification Evaluation Management Summary

3. Definition : Delayed Union When fracture takes more than usual time to unite Every fracture has its own timetable Long Bone shaft fractures – 6-9 months Femoral neck fractures- 3 months

4. Definition : Non-union USFDA Non-union is said to have occurred when 9 months have elapsed since injury and there are no visible progressive signs of healing for 3 consecutive months. Brinker A fracture, that in the opinion of treating physician, has no possibility of healing without further intervention.

5. Pseudoarthrosis Non-union may be painless if pseudojoint is formed between fracture ends Active movements is possible No synovial capsule

6. Fracture Healing Stages: Stages of hematoma formation Stage of Inflammation Stage of Soft callus formation Stage of Hard Callus formation Remodeling stage

7. Given by Stephen Perren States that , “A tissue cannot exist in the environment where the strain is greater than yield tolerance of the tissue. Yield tolerance – Bone-2% Cartilage-2-10% Granulation tissue/fibrous tissue- 100% Interfragmentary Strain Theory

8. Primary intention - Absolute stability Interfragmentary motion- < 0.15mm, fracture gap-<0.1mm Strain-<2% Secondary intention - Relative stability Interfragmentary motion - 0.2-1mm Strain 2-10% Gap Union Strain< 2% , gap – upto 1 mm Fracture Healing : Types

9. Non-union- Etiologies Multiple Biologic Local Systemic Mechanical Malreduction Inappropriate stabilization

10. Etiologies : Biologic Systemic Age Chronic Disease Diabetes Mellitus Manutrition Medications Smoking Local Excessive soft tissue stripping Bone loss Vascular Injury Infection

11. Smoking and Non-union Cigarette smoke contains 4800 constituents- 200 toxic Multifactorial Nicotine- a vasoconstrictor –reduction in peripheral blood flow Carbon monoxide reduces oxygen carrying capacity of blood Hydrogen cyanide- inhibits cytochrome oxidase C – prevents aerobic metabolism

12. Etiologies : Mechanical Inappropriate stabilization Too little fixation Too rigid fixation Inappropriate implant choice Inappropriate implant position Malreduction Malposition Malalignment Distraction

13. Neck of Femur Scaphoid Lower third tibia Lower 3 rd Ulna Lateral condyle humerus Common Sites

14. Classification Broadly – Aseptic and Septic Non union Aseptic Nonunion- Judet and Muller, Weber and Cech Based on viability of the bone ends Hypervascular : viable and capable of biological reaction Stable internal fixation is enough, noi bone graft is required Avascular : non viable and are not capable of uniting without intervention Needs rigid internal fixation and bone graft after decortication of non viable ends

15. Hypervascular Non-union Elephant foot : Hypertrophic, rich in callus Horse Hoop : mildly hypertrophic, poor in callus Oligotrophic : non hypertrophic Based on viability of the bone ends

16. Hypervascular Non union : Elephant Foot Hypervascular Non union : Horse Hoop

17. Avascular Non-union Torsion Wedge Non-union : Intermediate fragment has healed at one end and not at other end Comminuted Non-union : Gap Nonunion : Atrophic Nonunion : ends are thin and sclerotic with excess scar tissues in between

18. Comminuted Nonunion Gap Nonunion

19. Classification of Infected Non-Union Umiarov’s Classification Type 1 : Normotrophic without shortening Type 2 : Hypertrophic with shortening Type 3 : Atrophic with shortening Type 4 : Atrophic with bone and soft tissue defect Kulkarni’s Classification Type 1 : Fragments in apposition with mild infection and with/without implant Type 2 : Fragments in apposition with severe infection with small or large wound Type 3 : Severe infection with a gap or deformity or shortening 3A- defect with loss of full circumference 3B- defect in >1/3 of circumference 3c –defect with deformity

20. Paley et al Classification Type A<1cm of bone loss A1 (Mobile deformity) A2 (fixed deformity) A2-1 stiff w/o deformity A2-2 stiff w/ fixed deformity Type B>1cm of bone loss B1 w/ bony defect B2 loss of bone length B3 both Classification of Tibial Non-Union

21. Classification of Tibial Non-Union According to the classification of Paley et al Type A non-unions can be treated with restoration of alignment, followed by compression. Type B non-unions may require additional cortical osteotomy and either internal bone transport or overall lengthening to obtain the original bone length.

22. Diagnosis History Clinical Examination Serial X-rays Blood investigations

23. Diagnosis : History Symptoms : Minimal/No pain Loss of Function Initial velocity of injury Initial treatment Co-morbidities Current Medications Features suggestive of infections

24. Diagnosis: Examination Painless abnormal mobility Shortening Muscle wasting Scars/Sinuses Neurovascular examination Condition of soft tissues

25. Diagnosis: Investigations Serial X-rays CBC, ESR, CRP Pus/Discharge C/s CT scan

26. Diagnosis: X-RAY Gap between fracture fragments Fragments are rounded and sclerotic Amount of callus formed could be less or more Decreased density of bone is due to osteoporosis

27. Treatment Diamond Concept of Fracture Healing

28. Treatment : Principles Identify Septic or Aseptic Control of Infection Host Optimization Smoking cessation, Diabetes Control, Improving Nutrition Classify as Hypertrophic/Oligotrophic/Atrophic Stabilization +/- Bone graft Correction of Deformity

29. Treatment of Septic Union Two approaches used Classical/Conventional Approach Active approach Conventional Approach Infected and draining non union is converted to one that has not drained for months Requires longer duration Meticulous debridement + temporary stabilization done followed by antibiotics to eradicate infection Definite stabilization +/- Bone graft done once infection is controlled

30. Treatment of Septic Union Active Approach The objective of the active method is to obtain bony union early and shorten the period of convalescence and preserve motion in the adjacent joints . Union takes priority over infection Meticulous debridement and fixation is done in same setting followed treatment of infection Polymethyl Methacrylate Antibiotic Beads- Heat-stable antibiotics, such as tobramycin and gentamicin, can be mixed with PMMA and used locally to achieve 200 times the antibiotic concentration achieved with intravenous administration.

31. Treatment of Aseptic Non-Union Hypertrophic Non-Union : requires adequate stability Exchange Nailing Plate and screw fixation External Fixators Atrophic Non-Union: Decortication, bone grafting and stable fixation Bone Transport

32. Treatment Options Conservative Low Energy Ultrasound Stimulation Electrical and electromagnetic Stimulation IC Bone Marrow Injection PRP Injection Operative Dynamization Exchange Nailing Bone grafting Open reduction-Rigid internal fixation Bone transport- Ilizarov's technique Induced Membrane Technique Amputation

33. Ultrasound Theories stimulates the genes involved in inflammation and bone regeneration. increases blood flow through dilation of capillaries and enhancement of angiogenesis, increasing the flow of nutrients to the fracture site. chondrocyte stimulation is enhanced, which leads to an increase in enchondral bone formation . Protocol is to use the ultrasound equipment for 20 minutes once a day.

34. Electromagnetic Stimulation Bone growth stimulators - used in conjunction . External electrical stimulation -advantageous in infected nonunion or when surgery is contraindicated

35. Dynamization Involves removal of proximal or distal screws of statically locked Intramedullary nail Stimulates osteogenesis at the fracture site by increasing the contact area and enhanced compression force Screws from larger fragment usually removed Ideal time : 3-6 months

36. Exchange Nailing Removal of the current intramedullary nail, debridement of the medullary canal followed by insertion of a larger nail. Has advantage of reaming which provides some bone graft at fracture site and also allows larger nail size

37. Bone Graft Standard for treatment of atrophic non-unions Used to stimulate biologic response of healing in nonunion Also used to fill defects in fracture zone i.e. up to 6 cm intercalary defects of long bones Bone Grafting origins: Autogenous “the golden standard” Allograft Synthetic bone substitute Vascularised bone grafting

38. Bone Graft Has osteogenic , osteoinductive and osteoconductive properties Osteogenic – provides a source for vital bone cells Osteoinductive - contain proteins or chemotactic factors that attract vascular ingrowths and healing i.e.. dematerialized bone matrix & BMP’s Osteoconductive - contains a scaffolding for which new bone growth can occur i.e. allograft bone, calcium hydroxyapatite

39. Open Reduction and Plate fixation Non union site opened , fracture ends freshened and fixed along with bone graft. External Fixators relatively noninvasive and does not disturb soft tissues surrounding the nonunion. ability to correct deformity and provide stable fixation.

40. Illizarov’s Technique – Bone Transport Best for infected nonunions Corrects deformity + bone loss In hypertrophic - gradual compression Avascular- corticotomy , Bone transport and compression

41. Induced Membrane Technique Masquelet Technique Usually useful for segmental bone loss Two staged procedure Fracture part debrided and filled with bone cement which induces an osteogenic membrane Secondly, membrane opened, bone cement removed and filled with cancellous bone graft

42. Amputation A reconstructive procedure rather than failure of treatment. Properly fitted prosthesis after amputation better than a painful functionless limb. Indications in Non-union When reconstruction has failed W hen a proposed reconstructed limb would result in less functional limb than a properly fitted prosthesis When danger of major operation outweighs benefits Ehen reconstruction is not possible

43. Recent Advances Reverse Dynamization Newer perspective of Stephan Perren’s Interfragmentary Strain Theory Initial flexible fixation, resulting in cartilaginous model formation followed by rigid fixation at 2-4 weeks, resulting in woven bone formation

44. Recent Advances Bone Stimulants : BMPs, PRP, FGF Mesenchymal Stem Cells : Bone-marrow derived MSCs seeded on ceramic scaffold Gene Therapy: involves transfer of genetic material into the target genome. Transfer of genes for BMPs under study Bone tissue engineering Use of Systemic stimulants such as Teriparatide (recombinant Parathyroid Hormone) Studies have shown daily subcutaneous injection of teriparatide 20mcg enhances fracture healing

45. TAKE HOME MESSAGE Delayed union and non-union are common complication of fracture Multifactorial etiology Mechanical stability as well of biological environment is required for fracture healing

46. REFERENCES : Rockwood and Green’s Fractures in Adults , 8 th Edition Campbell’s Operative Orthopaedics , 13 th Edition Apley and Solomon’s System of Orthopaedics , 10 th Edition Concepts and Cases in Nonunion Treatment, AOTRAUMA Andrzejowski P, Giannoudis PV. The 'diamond concept' for long bone non-union management . J Orthop Traumatol . 2019 Apr 11;20(1):21. doi : 10.1186/s10195-019-0528-0 . PMID: 30976944; PMCID: PMC6459453 . Emara KM, Diab RA, Emara AK. Recent biological trends in management of fracture non-union .  World J Orthop . 2015;6(8):623-628. Published 2015 Sep 18. doi:10.5312/wjo.v6.i8.623

47. The Best Treatment for Non-Union is Prevention. -John Charnley Thank You