Proximal femur focal def

PFFD

1. Proximal Focal Femoral Deficiency DR.PONNILAVAN

2. INTRODUCTION An uncommon but complex problem. Femur shorter than normal and there is apparent discontinuity between the femoral neck and shaft. In many cases the defect in the proximal femur will ossify as the child grows older

3. EMBYOLOGY A teratogen is the term given to the agent that causes a malformation in an embryo or fetus. The teratogen for PFFD is unknown.PFFD is not genetic . Some have limb buds on the fetus develop at about 28-32 days into pregnancy and at 33-36 days the footis visible. If something affects the growth of fetus around this critical limb formation time[4-6 weeks] it can lead to PFFD

4. EMBYOLOGY Proposed that it is caused by anoxia [oxygen deficiency],ischemia [temporary blood supply deficiency],chemicals, hypothermia ,radiation, bacterial toxins, viral infections, enzyme and hormonal changes. Thalidomide a only definite cause during intrauterine-taken by mother between the 4 th and 6 th week of gestation.

5. What is the problem in PPFD?? Proxiaml femur partially is absent Entire limb overall shortened. Leading to : Limb length discrepancies Malrotation Proximal joint instability Inadequate of proximal musculature

6. frequency Very rare 1 case per 50000 population to 1 case per 200000 population

7. Etiology Sclerotome subtraction theory: Injury to the neural crest cells that from the precursors to the peripheral sensory nerves of L4 and L5 results in PFFD. Theory by boden et al: Defect in proximal proliferation and maturation of chondrocytes in the proximal growth plate.

8. Etiology Agents :anoxia ,ischemia ,irradiation ,bacterial and viral infections and toxins,hormones,mechanical energy ,thermal injury. Thalidomide a only definite cause during intrauterine-taken by mother between the 4 th and 6 th week of gestation. No evidence of genetic etiology Maternal diabetes:femoral hypoplasia

9. Clinical presentation Easily recognized The femur is shortened ,flexed ,abducted, and externally rotated. Flexion contractures of hip and knee present. Bulbous proximal thigh tapers to the knee. Hip instability : pistoning may be present. Knee is uniformly unstable in an anteroposterior plane secondary to absent cruciate ligaments. Generalized knee hypoplasia.

10. Clinical presentation A high incidence of fibular deficiency[70-80%] and valgus feet . 50% with some limb anomalies. Cleft palate ,clubfoot, congenital heart defects ,spinal anomalies –rarely occur. 15% cases bilateral.

11. CLASSIFICATION Aitken classification Himanishi classification Gillespie classification Fixsen and Lloyd-Robert classification Amstutz classification

12. CLASSIFICATION:AITKEN CLASSIFICATION

13. Hamanishi Classification More comprehensive than the Aitken system. It comprises 6 primary groups and 10 subgroups of femoral malformation, with a category for almost every deformity. The mildest form is a shortened femur with no radiographic defect (grade Ia ); the most severe is complete absence of the femur (grade V) .

14. Gillespie Classification In the clinically based, treatment-oriented Gillespie classification, patients are placed in one of three groups. In group A, the femur is up to 50% shorter than the normal femur, and the hips and knees can be made functional. These cases have also been called congenital short femur.

15. GROUP B Group B comprises those patients with more severely shortened femora in which the foot on the affected side reaches above the midtibia on the normal side, often at the level of the normal knee. With the hips flexed the femur is noted to be at or less than half the length of the contralateral femur. These patients are usually treated with amputation or rotationplasty and prosthetic management

16. GROUP C Patients in group C have a subtotal absence of the femur. Arthrodesis of the knee is not indicated in group C cases, and these patients will require prosthetic management.

17. Fixsen and Lloyd-Robert classification Type-1 Proxiaml femur is bulbous –no continuity between the femoral head,neck and greater trochanter. A pseudoarthrosis may form distal to greater trochanter.

18. Fixsen and Lloyd-Robert classification Type-2 Tuft or cap ossification at proximal end of femur that is separated from a blunt upper femoral shaft by an area of lucency . Pseudoarthosis present usually,and heals the femoral neck with a varus deformity. Hip is unstable.

19. Fixsen and Lloyd-Robert classification Type-3 Femur is blunt and pointed in shape ,there is no tuft at the proximal end of the shaft . All have unstable Pseudoarthrosis .

20. Amstutz classification Efficacy of MRI in classifying PFFD –more higher. Overs estimate the degree of deficiency and therefore ,MRI –best modality MRI based classification- Amstutz classifcation

21. Amstutz classification Amstutz further subdivided Aitken’s classification into five types. He divided class A in to types 1 and 2. Type 1 is reserved for the milder form with simple femoral shortening and coxa vara . In type 2, a subtrochanteric pseudarthrosis is present. The remaining types correspond to those of Aitken’s classification.

22. TREATMENT

23. Treatment options Equinus prosthesis only Ankle disarticulation and prosthetic fitting Ankle disarticulation and knee arthrodesis Ankle disarticulation and femoral pelvic arthrodesis Rotationplasty and knee arthrodesis Rotationplasty and femoral-pelvic arthrodesis

24. treatment If final predicted discrepancy at maturity is less than 20cm ,the child may be a suitable candidate for limb lengthening procedure.

25. Amputation Amputation of foot combined with knee arthrodesis. Consider also fusing the femur to pelvis to improve hip stability. Either a modified syme’s amputation or a boyd amputation

26. Knee fusion for prosthetic conversion in PFFD Into a single skeletal lever arm by arthrodesis of the knee in extension and syme ankle disarticulation.

27. Knee fusion for prosthetic conversion in PFFD Anterior S shaped incision –expose anterior aspect of distal femur and proximal tibia . Incision is extended laterally to expose the lateral aspect of the upper femur.

28. Knee fusion for prosthetic conversion in PFFD Capsule and synovium of knee opened With an oscillating saw the rticular cartilage of upper end of tibia is excised,until the ossific nucleus of epiphysis The distal femoral epiphysis is completely removed.

29. Knee fusion for prosthetic conversion in PFFD An 8 mm k-nail or similar nail inserted retrograde First it is inserted distally into the tibia ,exiting from the sole of the foot.

30. Knee fusion for prosthetic conversion in PFFD Nail passed proximally into the femur ,impacting the lower end of femur and the upper epiphysis of tibia in extension. Ensure – proper rotational alignment and fused knee is not in flexion Intramedullary nail should be in center to avoid growth retardation. One and one half spica cast is applied for immobilization.

31. Knee fusion for prosthetic conversion in PFFD Six weeks postoperatively ,when the intramedullary nail is removed ,a syme amputation is performed.

32. Knee fusion for prosthetic conversion in PFFD

33. Girl with bilateral femoral deficiency. Prostheses to increase her height are the only appropriate treatment measure.

34. Rotationplasty First described in 1930 by Borggreve , who used the procedure to treat a knee severely damaged by tuberculosis. In 1950, van Nes described his technique of treating congenital femoral deficiencies by rotating the foot of the affected limb 180 degrees so that the toes pointed posteriorly and the motion of the foot and ankle controlled the prosthetic knee

35. Rotationplasty:goal To convert the affected limb to a functional below – knee amputation in which the rotated foot serves as a knee joint.

36. After rotationplasty , the gastrocsoleus muscle provides primary motor control to the ankle, which, in essence, is now the “knee” extensor. Sensory feedback from the ankle also allows the patient better proprioceptive control of the prosthetic knee

37. In a study comparing the gait mechanics of patients who had undergone van Nes procedures with those who had undergone Syme amputations, the patients treated with rotationplasty demonstrated better prosthetic limb function and fewer compensations with the contralateral normal limb.

38. PFFD When the hip is stable and the femoral anatomy is relatively normal ,the two treatment options are knee arthrodesis with either a syme amputation or a rotationplasty . When the hip is unstable ,the current treatment options are a steel fusion to the pelvis with either a syme amputation or a rotationplasty or brown ilio femoral fusion with rotationplasty .

39. Steel procedure : the femoral segment is fused to the pelvis (iliofemoral fusion) in a flexed position, and the knee functions as a hip joint

40. The proximal femur is absent

41. Limb Lengthening The goals of limb lengthening procedures are to correct the existing deformity and to eliminate the length discrepancy. multiple complications, they should not be undertaken lightly. Current indications:congenital short femur include a limb that is predicted to be at least 50% as long as the normal limb at maturity, a predicted discrepancy of less than 17 to 20 cm, and a condition that can be corrected in three or fewer separate limb length equalization procedures.

42. Limb lengthening

43. Summary

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