Pseudoarthrosis tibia
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This document summarizes information about congenital pseudoarthrosis of the tibia (CPT), including: 1. CPT is characterized by a spontaneous fracture that heals poorly, often associated with anterolateral bowing of the tibia. While the term is a misnomer, an alternative name has not been established. 2. Key aspects of CPT include nonunion of a tibial fracture that develops spontaneously or after minor trauma in a dysplastic bone segment. It usually develops in the first two years of life and commonly affects the tibia and fibula. 3. Treatment approaches aim to achieve union at the fracture site while preventing refracture, correcting limb length inequality and growth abnormalities, and preventing
Pseudoarthrosis tibia
- 1. Congenital pseudoarthrosis of Tibia (CPT) Name of the student: Dr. Saikat Ghosh M.S (Orthopedic Surgery) Resident, Phase-B Chattogram Medical College, Chattogram.
- 9. Introduction • Congenital pseudarthrosis of the tibia and fibula (CPT) was first described by Paget in 1891 and is characterized by a spontaneous fracture that heals poorly with routine treatment. • Anterolateral bowing of the tibia, the precursor of CPT, is present at birth, although the fracture and the ensuing pseudarthrosis are rarely seen at this time. Although the term ‘congenital pseudarthrosis’ is thus a misnomer, an alternative name for the condition has not been forthcoming.
- 10. Definition Pseudoarthrosis: This is defined as a fracture that has undergone nonunion and a cleft develops between the bone ends resembling joint formation with end becoming convex and the other concave. The cleft or cavity gets filled with fluid and is lined by a membrane and pseudocapsule. The structure is hypermobile and has no restraints. Radiographically ,the characteristic appearance is that of “mortar and pestle”.
- 11. Pseudoarthrosis of Tibia • Congenital pseudoarthrosis of tibia (CPT) refers to nonunion of a tibial fracture that develops spontaneously or after trivial trauma in a dysplastic bone segment of the tibial diaphysis. • The pseudoarthrosis usually developes during the first 2 years of life. • Normally CPT is unilateral, located at the junction of the middle and distal thirds of the tibial segment with no predominance for sex or side. • The fibula is also affected in more than half the cases.
- 12. Is congenital pseudoarthrosis really congenital ??? • Congenital pseudoarthrosis of tibia is a misnomer it is often not a congenital one. The nonunion (pseudoarthrosis) develops usually after birth due to congenital ‘defect’ in tibia. • it is revealed by either pseudarthrosis at birth or by a pathological fracture presenting in bone with modifications such as bowing, narrowing of the medullary canal or a cyst.
- 13. Etiology • The exact cause of CPT is not known .Inheritant inability of the bone to form to form callus at the site of fracture.
- 14. Epidemiology • CPT is a rare condition, with a reported incidence ranging from one in 28,000 in Finland to one in 1,90,000 in the United Kingdom.
- 15. Types • Severe neonatal forms or primary pseudarthrosis, in which signs are present at birth, • secondary pseudarthrosis, which is revealed by a pathological fracture when the child begins walking.
- 16. Clinical feature Inspection: Anterolateral or anterior angulation /bowing of leg Signs of neurofibromatosis • Foot deformity • Ankle valgus • Skin dimple over angulation Palpation: • Thinning of tibia at angulation • Tenderness • Abnormal mobility (pathological fracture) • Wasting of calf muscles • Contracted and prominent tendo Achilles
- 17. Associated problems • (i) Leg length discrepancy, • (ii) multilevel multidirectional tibial deformity, • (iii) proximal migration of the fibula, • (iv) fibular nonunion, • (v) ankle mortise valgus, • (vi) ankle-joint dorsiflexion, • (vii) valgus contracture, • (viii) cavovalgus foot deformity, and • (ix) persistent dorsiflexion contracture before surgery.
- 18. Radiological appearance • The radiological appearance varies from bowing of the tibia with failure of formation of a normal medullary cavity, cystic lesions, and an associated incomplete or complete fracture of the tibia with atrophy and tapering at the site of the fracture and pointed distal fragment depending on stage. • Lesions associated with neurofibromatosis often show a typical appearance in which a segment of tibia or tibia and fibula show hourglass thinning, sclerosis and loss of the medullary cavity followed by a fracture through the dysplastic sites. • In lesions associated with fibrous dysplasia, there is cyst formation with expansion of the shaft of the bone, surrounded by sclerosis, ground-glass appearance and other features of fibrous dysplasia.
- 20. Pathology • There is a failure of normal bone formation in the distal half of the tibia, resulting in segmental defect of bone, anterolateral angulation and pathological fracture. • The site of pseudarthrosis is usually surrounded by a thickened periosteum and a thick, heavy cuff of poorly perfused hamartomatous fibrous tissue. They are said to prevent union by a mechanical effect of interposition and be responsible for defective vascularisation in the bone. The periosteum could create a fibrous band causing an increase in local pressure around the bone resulting in reduced vascularization as well as bone atrophy. The vascularlization defect could also be secondary to thickening of the vessel walls in the area of pseudarthrosis .
- 21. Physiopathology • Fibrous hamartoma replaces the healthy periosteum. • Fibrous hamartoma leads to osteolysis and vascular constriction of the bone. • The bone is viable despite the osteolysis, atrophy and hamartomatous constriction. • Medullary canal obliterated due to sclerosis. • Osteocytes produce lower levels than normal of BMP. • Increased osteoclasts and osteoclasis.
- 22. Neurofibromatosis • The criteria used by Crawford for diagnosis of neurofibromatosis requires at least two of the following: • (i) multiple café-au-lait spots, • (ii) positive family history of neurofibromatosis, • (iii) definitive biopsy, or • (iv) characteristic bony lesions, such as pseudarthrosis of the tibia, hemihypertrophy, or a short sharply angulated spinal curvature. • Café-au-lait spots are typically smooth edged. At least five spots measuring more than 0.5 cm in diameter are considered diagnostic of neurofibromatosis.
- 23. Neurofibromatosis and Pseudoarthrosis • The association of NF1 in 40 to 60% of the cases of CPT suggests a genetic cause. NF1 codes for a ubiquitous protein, neurofibromin, whose functions include the negative regulation of Ras, a protein involved in cell differentiation and proliferation . The mutation of NF1 results in a loss of neurofibromin activity resulting in the maintenance of the active form of Ras. The loss of function of neurofibromin can result in a Ras-MAPK pathway anomaly resulting in defective osteoblastic differentiation. Over expression of the Ras pathway can also result in an increase in osteoclast activity and their precursors, explaining bone resporption in CPT and the high rate of recurrent fractures.
- 24. Natural history of CPT • The natural history of CPT can be divided into primary and secondary. • the primary problems in CPT are: • 1) anterolateral bowing; • 2) non-healing fracture (pseudarthrosis) • 3) proximal migration of the fibula • Most of the secondary conditions are due to the effect of the primary condition on the surrounding soft tissues and joints and the secondary effects on growth and development of the lower limb.
- 25. Natural history of CPT • The secondary conditions are 1. atrophy and thinning of the calf muscles 2. calcaneo-cavus deformity of the foot with a pistol grip heel 3. dorsiflexion contracture of the ankle (calcaneus deformity of the foot) 4. lateral subluxation of the ankle joint, valgus wedging of the distal tibial epiphysis and instability of the ankle 5. proximal tibial physis grows into recurvatum and valgus 6. slowing of growth of the distal tibial and fibular physes and LLD 7. Coxa valga.
- 29. Investigations • Although the diagnosis can be made from plain radiographs, MRI provides excellent details of the extent of the pathological process.
- 31. Classification • There have been several different published classifications of CPT. 1. Anderson- 1973 2.Boyd-1982 3.Crawford-1986 4.Paley -2007 5. Apoil None of these classifications considers the status of the fibula. Choi et alclassified the fibula in CPT with emphasis on its level of proximal migration.
- 32. Crawford classification • The Crawford classification, which is the most frequently used today . This classification has the advantage of being descriptive and identifying the different stages as CPT progresses: • type I: anterior bowing with an increase in cortical density and a narrow medulla; • type II: anterior bowing with narrow, sclerotic medulla, • type III: anterior bowing associated with a cyst or signs of a prefracture, • type IV: anterior bowing and a clear fracture with pseudarthrosis often associating the tibia and fibula.
- 33. Boyd classification • The Boyd classification with 6 types, which has prognostic value: • type I: anterior bowing associated with other congenital malformations, • type II: anterior bowing with an hourglass appearance to the tibia. A fracture usually occurs before the age of 2. The ends of the bone are thin, rounded and sclerotic with obliteration of the intramedullary canal. This type is more often associated with NF1 type III: pseudarthrosis developing from an intraosseous cyst, usually at the middle and distal third junction. • type IV: sclerotic bone with no pathological bowing. The medullary canal is partially or completely obliterated. • type V: dyplasic appearance to the fibula. Pseudarthrosis can be located on either of the two bones of the tibial segment. • type VI: associated with an intraosseous fibroma or a
- 36. Anderson classification 1. Dysplastic 2. Cystic 3. Late 4. Clubfoot 5. Angulated
- 37. Apoil classification • type I: atrophic pseudarthrosis with thin bone ends. The ends of the bone are said to look like ‘‘barley sugar’’, which results in a more or less significant long-term loss of bone substance, or overlap. The inferior fragment is often small and aplastic, ending in an atrophic epiphysis. There is no medullary canal. The fibula has an identical lesion, • type II: tight, extensive hypertrophic pseudarthrosis. The bone ends are dense, wide and the medullary canal has disappeared, the cortex thickens on the concave side. The fibula is often bowed and abnormally shaped.
- 39. Differential Diagnosis • Congenital postero-medial bowing of the tibia and antero-medial bowing associated with fibular hemimelia. • congenital longitudinal deficiency of tibia (paraxial tibial hemimelia) • Fracture nonunion • Osteogenesis imperfecta • Ehlers Danlos syndrome • Fibrous dysplasia • Rickets • Post osteomyelitic pathological fracture.
- 40. Lessons prior treatment • Hamartoma resection should be comprehensive back to normal fat planes. • Medullary canal should be recanalized. • All bone and soft tissue at the CPT site should be alive. • Autogenous cancellous bone graft contains more stem cells than autogenous cortical or allograft bone and produces more bone for the same volume of graft. • Bone graft is rapidly resorbed. • Intramedullary fixation helps prevent refracture. • Rigid fixation is critical to provide mechanical stability at the CPT site. • BMP may be helpful to boost decreased BMP production by the diseased tibia.
- 41. Lessons • Zoledronic acid can help prevent osteoclasis at the CPT site. • Zoledronic acid given prior to bone graft harvest can protect the bone graft from resorption after implantation. • Angular correction at the CPT site is critical. • Periosteal grafting can help restore healthy periosteum at the CPT site.14 • Larger cross-sectional area of union at the CPT site has a lower risk of fracture.10,11 • Cases with accidental cross union between the tibia and fibula do not refracture.
- 42. Methods of Treatment 1. Conservative 2. surgical
- 43. Conservative treatment • Done for patients without fracture or pseudoarthrosis (prepseudoarthrosis). • Total contact plastic clamshell orthosis, AFO (prior to walking), KAFO (infant starting to walk). Worn indefinitely full-time; if fracture does not occur tibial bowing usually gradually improves and reformation of medullary canal often requires up to 5-10 years. If there is sufficient straightening of tibia, medullary canal is reformed and adequate cortical thickness then orthosis may be discontinued.
- 44. Goals of surgical treatment 1. Union at fracture site, maintaining union 2. Prevent refracture 3. Correct limb length inequality 4. Correct associated growth abnormalities 5. Prevent ankle deformity and arthritis.
- 66. Controversies in the management
- 67. The Cross union concept • Choi et al (2011) recommended creation of a cross-union between the tibia and fibula for CPT cases where the fibula was broken but minimally proximally migrated. They converged the two fibula bone ends towards the two tibia bone ends in what they called a ‘4-in-1 Osteosynthesis’. • They used a cortico-cancellous sheet of the inner table of the ilium with or without its periosteum and when necessary additional cortical bone from the contralateral tibia combined with cancellous bone chips to achieve the cross-union. The cortical graft was placed posterior to the two bones and then cancellous chips between the bones and another layer of cortical bone anterior to the bones. • They did not recommend this method when the fibula was intact or when the fibula was significantly proximally migrated.
- 68. Paley foundation cross union protocol • Paley (2012) reported preliminary results using combined pharmacological and surgical management with cross-union. • The treatment protocol was: • presurgical infusion of zoledronic acid (ZA) • hamartoma resection around tibia and fibula with resection of the interosseous membrane • tibial rodding with a telescopic growing rod and fibular rodding with a wire
- 69. Cross union • decancellousization of the ilium to harvest a large cancellous bone graft • harvest of periosteal graft from the underside of the iliacus muscle • application of a three-layer graft composed of 1) periosteum around the CPT, 2) cancellous bone between and around the tibia and fibula, and 3) BMP2 posterior and anterior to the bone graft covered by soft tissues • application of the Ilizarov apparatus to compress the CPT site and to give rotational stability .
- 72. Cross union • Fig. Reproduced with permission by the Paley Foundation: (a) anterior incision shown from front and cross section. Note hamartoma encircling tibia and fibula and the interosseous membrane between them; (b) anterior and deep posterior fasciotomy and muscle reflection to expose tibia, interosseous membrane, and fibula, allow resection of the membrane under direct vision without damage to the neurovascular bundles; (c) circumferential resection of the tibial fibrous hamartoma is carried out over the planned length of the cross-union. The same is done for the fibular hamartoma; (d) the tibial bowing is straightened and the bone ends overlapped and resected; (e) a customized Fassier-Duval telescopic nail is inserted and the male end locked with a wire into the distal epiphysis and the female end screwed into the proximal epiphysis; (f) a small diameter locking plate is fixed medially to the tibia with six screws; (g) the fibular ends can now be cut and the fibula fixed with a wire in its medullary canal; (h) a periosteal graft is harvested from the undersurface of the iliacus muscle. It is then expanded by passing it through the skin graft mesher; (i) decancellousization of the ilium is done by first splitting the two cortical tables of the ilium down to the roof of the acetabulum, triradiate cartilage, sciatic notch, posterior spines and sacro-iliac joint; (j) the periosteal graft is wrapped around the congenital pseudarthrosis site and bone morphogenic protein-2 (BMP2) collagen sponges are inserted overtop the posterior muscles behind the tibia and fibula (left). The cancellous bone is inserted between the tibia and fibula (left centre). The BMP2 sponges are placed overtop the bone graft (right centre). The anterior muscles lie over the BMP2. The interosseous space has a sandwich of cancellous bone between layers of BMP2 and its overlying soft tissues; (k) the cross-union forms between the bones by three months after surgery. The bone is well fixed with the telescopic rod in the tibia, the wire in the fibula and the plate on the tibia (left). Growth may occur despite the hardware leading to telescopic expansion of the male and female rods. The fibular wire descends with growth (left).
- 73. Prognostic Factors • Factors reported to negatively affect union: 1) neurofibromatosis; 2) age at treatment less than three years; 3) previous failed surgery; and 4) years of follow- up after treatment. Neurofibromatosis is often touted to be a negative prognostic indicator.
- 76. Jannatul Ferdous, 9 years old child 3 years ago had cellulitis in her right leg Abscess formation Incomplete drainage of abscess Development of osteomyelitis Maltreatment of osteomyelitis
- 77. After being admitted in CMCH • Sequestrum in tibia is excised • Cortical graft taken from ipsilateral fibila without periosteum • Grafted portion is fixed within gap of tibia by multiple screws and cerclage wires • Finally, external fixation is given • Ex-fix is removed after 6months .