Mandatory fasting for 8 hours, comprehensive physical examination, preoperative pelvic X-ray or MRI, baseline blood work (CBC, coagulation profile), cross-matching for potential blood transfusion, and informed consent. Prophylactic antibiotics must be administered within 60 minutes prior to the first incision.
Post-operative immobilization in a hip spica cast or brace as determined by the surgeon. Strict pain management protocol, monitoring of distal neurovascular status, physical therapy initiation for gentle range of motion once stable, prophylactic anticoagulation if required, and inpatient wound assessment. Discharge criteria include stable vital signs, controlled pain on oral medication, and successful mobilization to physical therapy goals.
Comprehensive Guide to Femoral Osteotomy for Developmental Dysplasia of the Hip (DDH)
Developmental Dysplasia of the Hip (DDH) remains one of the most significant orthopedic conditions encountered in pediatric clinical practice. When conservative management—such as the Pavlik harness or closed reduction—fails, or when the condition presents late, surgical intervention becomes mandatory. Among these interventions, the femoral osteotomy stands as a cornerstone procedure, designed to restore the physiological relationship between the femoral head and the acetabulum.
This guide provides an exhaustive clinical overview of femoral osteotomy for DDH, intended for orthopedic residents, surgical fellows, and clinical specialists.
1. Overview and Clinical Mechanism
A femoral osteotomy is a surgical procedure wherein the femur is cut and realigned. In the context of DDH, the primary goal is to address the persistent malalignment of the femoral neck and the hip joint.
The Pathophysiological Basis
In DDH, the hip joint often exhibits excessive femoral anteversion (the inward twist of the femur) and an increased neck-shaft angle (coxa valga). This anatomy forces the femoral head to sit eccentrically within the acetabulum, leading to:
* Reduced contact surface area: Increasing pressure on the acetabular labrum.
* Premature wear: Early-onset osteoarthritis.
* Joint instability: Risk of subluxation or dislocation.
By performing a derotational and/or varus-producing femoral osteotomy, the surgeon improves the "coverage" of the femoral head by the acetabulum, optimizes the biomechanics of the hip abductor mechanism, and ensures long-term joint stability.
2. Clinical Indications and Patient Selection
The decision to perform a femoral osteotomy is rarely made in isolation. It is typically part of a comprehensive reconstruction plan, often combined with pelvic osteotomies (such as the Salter or Pemberton).
Indications
| Indication Category | Clinical Detail |
|---|---|
| Persistent Dysplasia | Residual acetabular dysplasia despite non-operative or previous reduction attempts. |
| Increased Anteversion | Excessive femoral anteversion (>30–40 degrees) causing "in-toeing" gait or clinical instability. |
| Coxa Valga | Neck-shaft angle >140 degrees, which destabilizes the hip joint. |
| Failed Closed Reduction | When the femoral head cannot be adequately seated due to structural deformities. |
| Adolescent/Young Adult | Symptomatic residual DDH with early degenerative changes requiring realignment to offload the joint. |
Contraindications
- Active Infection: Septic arthritis or osteomyelitis.
- Severe Acetabular Hypoplasia: Where the acetabulum is too shallow to be covered by femoral realignment alone (requires pelvic osteotomy).
- Medical Instability: Poor systemic health preventing anesthesia or prolonged recovery.
3. Pre-Operative Preparation
Success in femoral osteotomy is predicated on meticulous planning. The "measure twice, cut once" mantra is vital here.
- Radiographic Assessment:
- AP Pelvis: To assess the Center-Edge (CE) angle and the Sharp angle.
- Frog-leg Lateral: To assess the femoral head-neck relationship.
- CT/MRI (3D Reconstruction): Critical for measuring exact degrees of femoral anteversion.
- Templating: Digital templating software is used to simulate the osteotomy level (usually intertrochanteric or subtrochanteric) and the amount of varus/derotation required.
- Blood Management: Children are at higher risk for blood loss; preoperative hemoglobin optimization and intraoperative cell salvage considerations are standard.
4. The Surgical Procedure: Technical Steps
The procedure is performed under general anesthesia with the patient in a supine position on a radiolucent table.
Step 1: Exposure
A lateral longitudinal incision is made over the proximal femur. The vastus lateralis is elevated from the lateral intermuscular septum to expose the subtrochanteric region.
Step 2: Osteotomy Level Selection
The osteotomy is typically performed at the subtrochanteric level. The surgeon identifies the lesser trochanter as an anatomical landmark. The cut must be distal enough to allow for adequate plate fixation but proximal enough to allow for the desired correction.
Step 3: The Cut
Using an oscillating saw under fluoroscopic guidance, the femur is osteotomized. The surgeon performs the cut perpendicular to the femoral shaft axis.
Step 4: Realignment (The Correction)
- Derotation: The distal fragment is rotated internally or externally as determined by pre-op CT.
- Varization: A wedge of bone (if needed) is removed to reduce the neck-shaft angle.
- Fixation: A pediatric hip plate (e.g., 90-degree blade plate or locking plate) is applied. This is the most critical step; the plate must hold the femur in the new position while allowing for union.
Step 5: Closure
The wound is closed in layers, with careful attention to the fascia lata and skin. A drain may be placed if significant soft tissue dissection was performed.
5. Post-Operative Recovery and Rehabilitation
Recovery is a phased process, typically lasting 6 to 12 months for full activity.
- Phase I (0–6 Weeks): Immobilization. A spica cast or hip abduction brace is often utilized to prevent excessive hip motion. Non-weight bearing (NWB) is strictly enforced.
- Phase II (6–12 Weeks): Radiographic confirmation of callus formation. Gradual transition to partial weight-bearing (PWB) and physical therapy focusing on range of motion (ROM) and gentle strengthening.
- Phase III (3–6 Months): Full weight-bearing. Focus on gait normalization and strengthening the gluteus medius, which is often weakened by the procedure.
6. Complications and Risks
While generally successful, femoral osteotomy is a major surgical procedure with specific risks:
- Avascular Necrosis (AVN): The most feared complication, resulting from damage to the medial circumflex femoral artery.
- Non-union/Malunion: Failure of the bone to heal in the corrected position.
- Hardware Irritation: Prominent plates or screws may require removal after bone healing (typically 12–18 months post-op).
- Loss of Correction: If the hardware fails or the correction was underestimated.
- Infection: Standard surgical site infection risk, managed with prophylactic antibiotics.
7. Alternative Treatments
Depending on age and severity, other options may be considered:
1. Pelvic Osteotomy (Salter/Pemberton/Dega): Often performed with femoral osteotomy, but can be done alone for purely acetabular dysplasia.
2. Periacetabular Osteotomy (PAO): Specifically for older adolescents and adults with mature skeletons.
3. Total Hip Arthroplasty (THA): Reserved for end-stage degenerative disease where reconstruction is no longer viable.
8. Frequently Asked Questions (FAQ)
1. At what age is a femoral osteotomy typically performed?
It is most common between ages 2 and 10, but can be performed in adolescents and young adults if the hip is still salvageable.
2. Is hardware removal necessary?
Not always, but it is common in children to prevent the plate from interfering with future growth or causing soft tissue irritation.
3. Will my child have a limp after the surgery?
A temporary limp is expected during rehabilitation. With proper physical therapy, most patients return to a normal gait.
4. How long does the surgery take?
Typically 2 to 4 hours, depending on whether it is a unilateral or bilateral procedure and if a pelvic osteotomy is also performed.
5. What is the success rate?
Success rates are high (often >90%) in restoring joint stability and delaying the onset of arthritis, provided the dysplasia is caught early.
6. Does the hip grow differently after the surgery?
The surgery is designed to normalize the biomechanics so that growth continues in a more physiological, stable environment.
7. How much pain should be expected?
Post-operative pain is managed with a multimodal approach, including nerve blocks and scheduled analgesics.
8. Can both hips be operated on at once?
Yes, bilateral procedures are performed, though they require a longer recovery and more intensive physical therapy.
9. What is "derotation"?
It is the act of turning the distal femur to correct the inward or outward twist, ensuring the hip joint sits squarely in the socket.
10. When can my child return to sports?
Usually, non-contact sports can resume at 6 months, while contact sports are typically delayed until 9–12 months post-op, contingent on radiographic healing.
Conclusion
Femoral osteotomy for DDH is a sophisticated, highly effective procedure that serves as the bridge between a dysplastic, unstable hip and a functional, long-lasting joint. By addressing the fundamental anatomical abnormalities of the femur, surgeons can significantly improve a patient's quality of life and decrease the lifetime risk of premature hip replacement. Success is defined not just by the precision of the cut and the stability of the fixation, but by the dedication to the post-operative rehabilitation protocol. Clinicians should approach each case with a clear understanding of the patient's unique biomechanical needs, ensuring that the realignment is tailored for long-term joint preservation.