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( اللَّهُ الَّذِي خَلَقَكُم مِّن ضَعْفٍ ثُمَّ جَعَلَ مِن بَعْدِ ضَعْفٍ قُوَّةً ثُمَّ جَعَلَ مِن بَعْدِ قُوَّةٍ ضَعْفاً وَشَيْبَةً يَخْلُقُ مَا يَشَاء وَهُوَ الْعَلِيمُ الْقَدِير) صدق الله العظيم. MANAGEMENT OF CONGENITAL COXA VARA. By Salah Mahmoud Abdelkader M.B.B.Ch. Supervisors.
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(اللَّهُ الَّذِي خَلَقَكُم مِّن ضَعْفٍ ثُمَّ جَعَلَ مِن بَعْدِ ضَعْفٍ قُوَّةً ثُمَّ جَعَلَ مِن بَعْدِ قُوَّةٍ ضَعْفاً وَشَيْبَةً يَخْلُقُ مَا يَشَاء وَهُوَ الْعَلِيمُ الْقَدِير) صدق الله العظيم
MANAGEMENT OF CONGENITAL COXA VARA By Salah Mahmoud Abdelkader M.B.B.Ch
Supervisors Prof. Dr. Abdelfatah Kotb Ismail Wali Professor of Orthopaedic Surgery Faculty of Medicine Zagazig University Dr. Hossam Mohammed Khairy Assistant Professor of Orthopaedic Surgery Faculty of Medicine Zagazig University Dr. Mohammed Elsadek Attia Lecturer of Orthopaedic Surgery Faculty of Medicine Zagazig University
A CKNOWLEDGMENT Before and above all thanks to "Allah" to whom I always pray to bless my work. It is a great honor for me to work under supervision of Prof. Dr. Abdelfatah KotbIsmail Wali,Professor of Orthopaedic Surgery, Faculty of Medicine, Zagazig University. For kindly accepting to supervise this work and for the valuable advice and encouragement he honestly offered throughout the course of this work. I'm very grateful toDr. Hossam Mohammed Khairy,Assistant Professor of Orthopaedic Surgery, Faculty of Medicine, Zagazig University. For his sincere continuous help, true advice, valuable guidance, kind supervision and constant purposeful encouragement which provided me all facilities during the conduction of this work. I would like to express my profound gratitude and deep appreciation toDr. Mohammed Elsadek Attia, Lecturer of Orthopaedic Surgery, Faculty of Medicine, Zagazig University. Without his precious advice and guidance, this work wouldn't have come to light. I'm also grateful to all members of the Orthopaedic Department, Zagazig University for their kind help and support. Without their cooperation, this work wouldn't have come to light.
Coxa vara Coxa vara includes all forms of decrease of the femoral neck shaft angle to less than 120-135°. This condition has many causes including: congenital, acquired, and developmental.
Conganital coxa vara Developmental abnormality Primary cartilagenous defect in femoral neck with • Abnormal decrease in femoral neck shaft angle • Shortning of femoral neck • Relative overgrowth of greater trochanter • Shortening of affected lower limb
ANATOMY OF THE HIP The hip joint is a synovial joint formed by the articulation of the rounded head of the femur and the cup-like acetabulum of the pelvis
Upper Femoral Epiphysis The upper femoral epiphysis is a pressure epiphysis which is applied at the upper end of the femur and subjected to pressure transmitted through the hip joint into which it enters
Resting Zone Proliferating Zone Hypertrophic Zone Ossification Zone Trabecular bone
HIP JOINT BIOMECHANICS A multi-axial ball-and-socket hip provides motion in three planes. Flexion-extension occurs within the transverse plane, abduction-adduction within the sagital plane, and internal-external rotation within the coronal plane Because the acetabulum and femoral head are incongruent and neither is strictly spherical, rolling and gliding occur within the hip joint. In a pure ball-and-socket only gliding occurs
Etiology Unknown may be. 1. Mechanical intrauterine stresses affecting hip development 2. Avascular necrosis involving selected areas of the proximal femoral physis/head and neck 3.Metabolic abnormalities causing deficient production of, or a delay in, the normal ossification process of the proximal end of the femur. 4. Primary cartilagenous defect in femoral neck- • Remains the most widely accepted theory on the cause of CCV
Pathophysiology of Coxa Vara the normal hip the compressive force is perpendicular to the center of the hip joint. As a result, the physeal cartilage and hyaline cartilage of the acetabulum are under compressive force, which is distributed throughout. Stresses on the medial side of the femoral neck are compressive, whereas those on the lateral side are tensile.
The upper femoral epiphysis tends to tilt and become displaced medially, and the tensile stresses increase.growth of the femoral neck is less on the medial side than on the lateral side.
In coxa varawith a progressive decrease in the femoral neck–shaft angle the physis changes its position from horizontal to vertical, The shearing force across the physis gradually increases • Coxa vara the femoral neck–shaft angle is decreased;the tip of the greater trochanter is elevated, and the position and direction of muscular force are altered.The resultant compressive force diverges more than normal in coxa vara, and the lever arm of the abductor muscles is lengthened.
Clinical Presentation Usually present with gait abnormalities Affected children generally present between the time they begin ambulation and age 6 years. (does not manifest until after birth and usually not until walking age)
Unilateral Case • Painless Limp (due to combination of trendlenburg gait and limb length inequality) • Easy fatigability , aching pain around gluteal muscles Bilateral Case- • Waddling gait • With or without fatigue or muscular pain
On Examination • Abduction (decreased articulo-trochanteric distance) and internal rotation (decreased femoral anteversion or true retroversion associated with this condition) limited on affected side • Trendlenburge test positve
No telescoping end negative Ortolani’s sign (DD from. DDH) Shortening in unilateral case (seldom exceeds 3 cm at skeletal maturity even in untreated patient) Evidence of genrelized skeletal dysplasia should be sought especially if family history positive
Radiographic Findings CCV is differentiated radiographically from other forms of proximal femoral varus by • The characteristic finding of an inverted Y-shaped lucency This lucency is made up of the proximal physeal plate and a fragment of bone inferolateral to the physis, which represents a contained area of abnormal calcification
Other more generic radiographic features are shared with the other causes of coxa vara. These include: • decreased neck shaft angle, often approaching or less than 90° • smaller and flatter femoral head • more vertical orientation of the physeal plate • decreased femoral anteversion or even retroversion of the head on the femoral neck • shallow acetabulum with a more oval shape.
Characteristic radiographic findings of congenital coxa vara. (A) Decreased neck shaft angle. (B) Smaller and flatter femoral head. (C) More vertical orientation of physeal plate. (D) Coxa brevis. (E) Abnormal bony fragment inferolateral to physeal plate and contained in inverted Y-shaped lucency
CT scan, with possible 3-dimensional reconstructions • CT scan can be used to help delineate the proximal femoral defect. It commonly reveals displacement of the proximal femoral epiphysis and associated metaphyseal spike of bone, from its normal superior-anterior position on the femoral neck to an inferior-posterior position. This results in relative femoral retroversion with respect to the head-shaft relationship. • CT scan may provide useful information regarding femoral anteversion or retroversion and the amount of bone stock in the area, which is important information for preoperative surgical planning.
MRI • MRI findings include widening of the growth plate with expansion of cartilage medio-distally between the capital femoral epiphysis and femoral metaphysis. • The usefulness of MRI as a preoperative imaging modality, in both diagnosis and surgical planning, is relatively limited.
Treatment 1-Non surgical 2-Surgical
Non-surgical • Non surgical treatment during childhood has historically been unsuccessful in achieving the objectives of proper treatment. Surgical correction is essential • Spica cast immobilization with the affected limb in abduction for 6 to 12 months have been reported to be unhelpful.
Indications of Surgery • If the Hilgenireiner epiphyseal (HE) angle greater than 60 degrees corrective surgery should be performed. • If the angle is less than 45degrees spontaneous correction will occur without surgery • Between 45 to 60 degrees represent a gray zone and the outcome is uncertain and careful observation is requiring before any decision is made. • A proximal femoral neck-shaft angle of less than or equal to 90 to 100 degrees. • A documented progressive decrease in the proximal femoral neck-shaft angle. • Development of a Trendelenburg gait.
Diagram of Hilgenreiner’s epiphyseal angle in CCV and normal hip
Aims of treatment • Correction of the neck shaft angle to a more physiologic angle and HEA to less than 35-40°. • Changing of the loading characteristics seen by the abnormal femoral neck from shear to compression. • Correction of limb-length inequality. • Reestablishment of a proper length tension relationship for the abductor muscle. • Correction of femoral anteversion (or retroversion) to more normal values. • Ossification and healing of the defective inferomedial femoral neck fragment.
Timing of surgery Corrective osteotomy is best performed not at a particular age but rather as soon as the criteria for surgical intervention are manifest. With the proper indications, a delay in surgical intervention until an older age in hopes of achieving better internal fixation is not justified. The progressive proximal femoral deformity and dysplastic changes at the femoral head, neck, and acetabulum that occur with time will make complete and lasting correction much more difficult
Methods of Treatment • Femoral neck procedures • Intertrochanteric osteotomy • Wagner multiple K-wire osteosynthesis • Langenskiold’s osteotomy • Pauwels Y-shaped osteotomy
Subtrochanteric osteotomies • Trochanteric epiphysiodesis • New techniques 1-Fixation using a modified veterinary plate 2-The use of external fixator (A low-profile illizarov)
FEMORAL NECK PROCEDURES • Historical surgical procedures included attempts to fix the defect of the femoral neck with pins or bone grafts; these approaches failed because they did not correct varus deformity, probably did not prevent progression of the deformity, and could produce growth arrest of the capital femoral physis.
Intertrochanteric osteotomies • Intertrochanteric osteotomies - Wagner multiple K-wire osteosynthesis -Pauwels Y-shaped -Langenskiöld valgus-producing osteotomies However these osteotomies have a somewhat limited ability to correct the associated femoral neck retroversion.
Langenskiold’s Osteotomy • Langenskiold’s osteotomy was used only when the neck shaft angle was lower than 80 degrees
SUBTROCHANTERIC VALGUS OSTEOTOMIES The subtrochanteric valgus-producing osteotomies have provided good and lasting clinical results The subtrochanteric osteotomy is fixed internally with either a blade plate or screw and plate combination.
A, Two-year-old girl with congenital coxa vara. B, Preoperative radiograph shows neck-shaft angle of less than 90 degrees bilaterally at age 5 years. C, After bilateral subtrochanteric osteotomies and internal fixation with pediatric hip screw
A lateral view of the Synthes five-hole veterinary plate. The plate on the left is in its original form, whereas the plate on the right has been pro-bent in the manner carried out before surgical implantation in the child. The plate accepts standard small fragment 3.5 mm cortical screws
Advantages • include avoidance of large open exposure and decreased potential for significant blood loss, while achieving an accurate and sustained correction of the triplanar deformity. • With an opening wedge osteotomy, limb length discrepancy is improved without compromising the quality and time of bony union. By avoiding the need for any supplemental cast immobilization, early mobilization with a short hospital stay is possible.
Problems associated with internal fixation such as prominent hardware, implant failure, the possibility of violating the proximal femoral growth plate, the need for second major surgical procedure for removing an internal implant, and the potential for deep infection are significantly decreased
Disadvantages These include a need to be familiar with the use of the llizarov fixator,The inconvenience of the pin sites with the possibility of drainage around the pins is another drawback: • Despite well-performed the other osteotomy, the literature cites recurrence rates as high as 30% to 70%.