Congenital condition caused by a defect in the primary ossification center of the proximal femur. Spectrum of disease includes Absent hip Femoral neck pseudoarthrosis Absent femur Shortened femur
EPIDEMIOLOGY Bilateral (15%)
ETIOLOGY Pathophysiology Defect in the primary ossification center (cartilage anlage). Different types of PFFD in patients with pappas type III, IV, VII, VIII, or IX deficiency Genetics Primarily sporadic etiology, but rare autosomal dominant form exists. Associated with sonic hedge-hog gene (limb bud).
Associated conditions Orthopedic manifestations Fibular hemimelia (50%) ACL deficiency Coxa vara Knee contractures Non orthopedic manifestations Dysmorphic facies found in rare autosomal dominant type
Aitken classification Class Femoral head Acetabulum A Present Normal B Present Mildly dysplastic C Absent Severely dysplastic D Absent Absent CLASSIFICATION
Class A - A shortened femur is present proximally, ending at or slightly above the level of the acetabulum; the femoral head is often absent but later ossifies; femoral head presence is indicated by a well-developed acetabulum; additionally, there is a subtrochanteric defect, which eventually ossifies and thereby establishes bony continuity; after ossification, there is usually a residual subtrochanteric varus deformity Class B - There is a more severe defect or absence of the proximal femur, and the defect does not heal spontaneously; at skeletal maturity, there is no connection between the femoral head and proximal femur; the end of the proximal femur is above the acetabulum; the femoral head, though present, may have delayed ossification, and there is often a bony tuft on the proximal end of the shaft Class C - There is an absent femoral head that does not ossify and a markedly dysplastic acetabulum; the femoral shaft is shorter than in a person with class B, in whom the entire proximal femur, including the trochanters, does not develop Class D (the most severe form) - There is a severely shortened shaft, which often has only an irregularly ossified tuft of bone proximal to the distal femoral epiphysis; no acetabulum is present, because the lateral pelvic wall is flat
In a symposium, Gillespie proposed a more functional classification system, in which patients were divided into three treatment groups from a surgical and prosthetic viewpoint. [15] The groups in this system were as follows : Group A - Possible candidates for limb-lengthening; this group included individuals who had congenitally short femurs but clinically stable hips, had no significant knee flexion contractures, and had the ipsilateral foot at or below the level of the middle of the contralateral tibia Group B - Patients classified by Aitken as classes A, B, and C and who required prosthetic treatment. Therefore, any surgical procedure is designed to maximize prosthetic function Group C - The same patients as Aitken class D, in that they had subtotal absence of the femur; Gillespie also recommended prosthetic treatment for his group C patients, but these patients did not require knee fusions before prosthetic fitting
PRESENTATION History
Physical exam Severe shortening of one or both legs Percentage of shortening remains constant with growth Short bulky thigh that is flexed, abducted, and externally rotated Normal feet (most common)
Diagnosis Diagnosis is made with radiographs of the hip and femur . Plain radiographs - an apparent loss of continuity between the femoral shaft and the head/neck. USS & MRI are particularly useful for assessing the exact nature of the tissue at the loss of continuity. MRI is also useful for evaluating unossified structures, the hip joint, adjacent soft tissue, the knee, and other malformations of the limb.
Management Management of proximal femoral focal deficiency (PFFD) requires a multidisciplinary team, which includes the pediatric orthopedic surgeon, prosthetists , and physical therapists . No single treatment approach applies to all cases. Each person with PFFD must be assessed individually.
Treatment is either nonoperative or operative. Depending on, Location and size of the femoral defect As well as presence of bilateral involvement.
Goals of treatment Treatment must be individualized based on, Ultimate leg length discrepancy. Presence of foot deformities. Adequacy of musculature. Proximal joint stability.
Non Operative Observation Extension prosthesis Operative Ambulation without prosthesis Limb lengthening with or without contralateral epiphysiodesis . 2. Ambulation with a prosthesis Knee arthrodesis with foot ablation Femoral-pelvic fusion (brown's procedure) Van ness rotation plasty Amputation
Non Operative Observation Indications Often in children with bilateral deficiency 2. Extension prosthesis Indications Less attractive option due to large proximal segment of prosthesis Assists patient when attempting to pull self up to stand
Operative - Ambulation without prosthesis Limb lengthening with or without contralateral epiphysiodesis Indications Predicated limb length discrepancy of <20 cm at maturity Stable hip and functional foot Femoral length >50% of opposite side Femoral head present ( aitken classifications A & B) Contraindications Unaddressed coxa vara , proximal femoral neck pseudoarthrosis , or acetabular dysplasia
Knee arthrodesis with foot ablation Femoral-pelvic fusion (brown's procedure) Van ness rotation plasty Amputation Operative - Ambulation with a prosthesis
1. Knee arthrodesis with foot ablation Indications: Ipsilateral foot is proximal to the level of contralateral knee. Prosthetic knee will not be below the level of the contralateral knee at maturity. Need for improved prosthetic fit, function, and appearance.
2. Femoral-pelvic fusion ( B rown's procedure) Indications Femoral head absent ( aitken classifications c & d)
3. Van ness rotation plasty Indications Ipsilateral foot at level of contralateral knee Ankle with >60% of motion Absent femoral head ( aitken classifications C & D) Surgical technique 180 degree rotational turn through the femur Ankle dorsiflexion becomes knee flexion Allows the use of a below-knee prosthesis to improve gait and efficiency
4. Amputation Indications Femoral length <50% of opposite side Surgical technique Preserve as much length as possible. Amputate through the joint, if possible, in order to avoid overgrowth which can lead to difficult prosthesis fitting fit for prosthesis for lower extremity after 1 year.