CONGENITAL PSEUDO ARTHROSIS OF TIBIA jainam.pptx

Heres ppt on most wanted topic - CPT by pediatric Orthopaedic Resident - Dr Jainam Salot. Suggestion welcomed at [email protected].

1. CONGENITAL PSEUDARTHROSIS OF TIBIA Dr Jainam Salot CNBC

2. TYPES ANTEROLATERAL BOWING - CPT POSTEROMEDIAL BOWING - BENIGN ANTEROMEDIAL BOWING – FIBULAR HEMIMELIA

3. TOPICS DEFINITION / INTRODUCTION ASSOCIATION CLINICAL FEATURES CLASSIFICATIONS TREATMENT MODALITIES COMPLICATIONS

4. DEFINITION:- Pseudoarthrosis is a false joint associated with abnormal movements at the site INTRODUCTION:- Congenital pseudarthrosis of tibia refers to segmental dysplasia of tibia+/- fibula causing AL bowing and eventual fracture. Also known as Anterolateral Bowing with Congenital Dysplasia of tibia Rarely present at birth , so it’s a misnomer

5. ASSOCIATIONS 55% - NEUROFIBROMATOSIS 15% - FIBROUS DYSPLASIA AMNIOTIC BAND SYNDROME CPT is rare & Usually develops in first 2 yrs of life. Etiology is unclear. Incidence is 1: 250,000

6. PATHOLOGY Thickened Fibrous tissue at the pseudoarthrosis site k/a HMARTOMA Pathology is periosteal in origin & not in bone Accompanied by paucity of vascular ingrowth Abnormal expression of type 3 collagen in periosteum

7. CONTD…. Hamartoma cells don’t differentiate into osteoblast in response to BMP They are more osteoclastic Thus treatment consist of removal of Abnormal hamaromatous tissue as well as reduce bone resorption & enhance bone repair

8. Primary Problems Anterolateral Bowing Recurrent Non healing fractures (Early) Proximal Migration of fibula Distal tibia growth arrest and subsequent ankle valgus

9. Anterolateral Bowing

10. Non healing Fractures leads to LLD Causes Proximal femur to compensate & causes coxa valga Severe coxa valga can cause Hip subluxation/dysplasia

11. Neurofibromatosis • NF-1 occurs due to mutation on the gene coding for NEUROFIBROMIN on chromosome 17. • Neurofibromin is expressed in a broad range of cells & tissue type. • It negatively regulates Ras activity ( cell proliferation & function) • It’s deficiency leads to increased Ras activity. • Affects Ras -dependent MAPK( mitogen activated protein kinase) activity which is essential for osteoclast function & survival.

12. CLINICAL FEATURES • Associated with anterolateral bowing of tibia. • Bowing usually occurs at the junction of middle & distal third. • Deformity may be associated with skin dimple, LLD, dysplasia of fibula & ankle valgus. Limp • Frank Mobility at Pseudoarthrosis Site. • Cutaneous signs of neurofibromatosis

13. CLASSIFICATION There is no universally agreed system based on both clinical features & radiographic findings. CAMURATI ADGLEY BOYD APOIL ANDERSEN CRAWFORD TACHJIAN BOYD & ANDERSEN are commonly used.

14. TACHJIAN CLASSIFICATION EARLY ONSET- FRACTURE OCCURS BEFORE 4 yrs OLD LATE ONSET – AFTER 4 yrs , FRACTURE OCCURS

15. Boyd classification • Boyd divided CPT into 6 types :- Type 1 :- Pseudarthrosis occurs with anterior bowing. A defect in tibia present at birth. Other congenital deformities may be present which may affect the management of pseudarthrosis .

16. Type 2 :- Pseudarthrosis occur with anterior bowing & a hourglass constriction of the tibia. Spontaneous fractures or after minor trauma. Commonly occur before 2 yrs of age. Also known as HIGH RISK TIBIA. Tibia is tapered, rounded, sclerotic & obliteration of medullary canal. Most common type. Associated with NF-1 Poorest prognosis.

17. Type 3 :- Pseudarthrosis develops in a congenital cyst usually near the junction of middle & distal third of tibia. Anterior bowing may precede or follow the development of fracture. Recurrance of fracture is less common after treatment.

18. Type 4 :- Originates in a sclerotic segment of bone. Without narrowing of tibia. Medullary canal is partially or completely obliterated. An insufficiency or stress fracture develops in the cortex of tibia & gradually extends through the sclerotic bone. Prognosis is good.

19. Type 5 :- Pseudarthrosis of tibia occurs with a dysplastic fibula. Pseudarthrosis of both bone may develop. Prognosis is good if the lesion is confined to fibula. If the lesion progress to tibia then the natural h/o usually resembles type 2. Type 6 :- Occurs as an intraosseous neurofibroma or schwannoma Extremely rare.

20. Crawford classification

21. PALEY’S CLASSIFICATION

22. TREATMENT AIMS 1. Achieve union 2. Prevent refracture 3. Correct LLD 4. Correct associated residual deformities of leg and ankle.

23. Prophylaxis first step is to prevent fracture if possible. • In an infant before walking age, no specific treatment is needed other than education of the caretakers. Once the child begins weight bearing, prophylactic bracing should be attempted. • A clam shell like orthosis that provides circumferntial support is usually recommended. • Protection of the unfractured tibia should be continued indefinitely till skeletal maturity or until patient approaches skeletal maturity.

24. SURGICAL OPTIONS Usually at 2.5 years 1. Autogenous bone grafting 2. External fixation 3. Intramedullary nail 4. BMP 5. Electrical stimulation 6. Periosteal Grafting 7. Amputation

25. 1. Autogenous bone grafting Non-Vascularized Cancellous bone(Good osteogenic potential) Non vascularized cortical bone(Resists Resorption) Vascularized bone(Predominantly cortical)

26. Mostly performed after 5 years of age

27. Useful in patients having defect more then 3 cm after resection of pseudoarthrosis Use of Ipsilateral fibula has advantage The fibula pseudoarthrosis if present should be at same level or below level so that transferred segment spans the pseudoarthrosis

28. McFarland Grafting Graft from opposite tibia is harvested in affected Limb after Interval of 4-6 wks Disadvantage Normal leg disrupted No deformity correction

29. 2. EXTERNAL FIXATOR Ilizarov is one of the treatment of choice for CPT ADVANTAGE Allows total resection of pathologic site Allows correction of axial deformity Full support immediately after correction DISADVANTAGE Psychological consequences Poor foot & ankle function if frame includes it Refracture Ilizarov Fixation with IM nailing can be done to correct deformity & decrease chance of refracture.

30. 3. Intra medullary nail Excision of the pseudoarthrosis by excising the tapered ends of the bone until fresh bleeding is encountered, Excise fibrous tissues, Excise Circumferentially 1 cm of periosteum from tibial ends Resection is followed by Fixation with IM rod & Autogenous cortical Bonegraft . Three struts of cortical bone are placed around the site of the excised pseudarthrosis after ensuring that the fragments are well apposed.

31. Post Op Immobilization In cast for 6-8 wks Helps to maintain alignment & prevent refracture Rigid AFO given as Rod may cross ankle & subtalar Joint Ideally IM rod should be retained till skeletal maturity to prevent Refractures+ bracing.

32. Bone Morphogenic Proteins BMP-2 & BMP-7 are used BMP soaked collagen sponge carrier is wrapped around graft & placed around pseudoarthrosis Site BISPHOSPHONATES given with them to optimize treatment This combination of BMP and bisphosphonates is also included in Paley’s cross-union protocol A recent study by Memeo et al. focused on the effect of bone marrow aspirate on healing in CPT. At 2 years followup , bone marrow aspirate concentrate sped healing by 1.7 months, which finding was significant;

33. Laine et al. reported a series of 10 patients treated with anterior lateral distal tibial–guided growth prior to tibial fracture and pseudarthrosis with growth modulation beginning at a mean age of 2.6 years. At a mean of 5.9 years follow-up, no patients studied had sustained fracture. The authors emphasize the need for obliquely oriented imaging to capture the plane of deformity and plan implant positioning.

34. AMPUTATION Resistant Pseudoarthrosis Shortening Atrophy Stiffness Dysfunctional Angular deformity Ankle disarticulation recommended BK Amputation or trans pseudoarthrosis amputation only if removal of osteomylitic bone & mature patirnt with less potential of bony overgrowth.

35. COMPLICATIONS Refracture(30% cases) Ankle Valgus- Relative Growth Inhibition of Lateral tibial physis distally LLD- due to pseudoarthrosis resection -Multiple surgeries causing damage to physis distally

36. To Prevent LLD <5 cm – C/L Epiphysiodesis >5 cm – Tibial Lengthening

37. Poor prognosis Neurofibromatosis Age at treatment less then 3 yrs Previous Failed Surgery Years of followup after treatment

38. Thank You