DDH – Rx Complications

Developmental Dysplasia of the Hip (DDH) – Treatment Complications

High-Yield Summary

Developmental Dysplasia of the Hip (DDH) treatment aims to achieve a stable, concentric reduction of the femoral head within the acetabulum to optimize hip function and prevent early arthritis. Despite advances, complications such as redislocation and avascular necrosis (AVN) remain significant challenges that impact long-term outcomes. Understanding the risk factors, early recognition, and management strategies for these complications is critical for optimizing patient prognosis.

Key Diagnostic Findings

Anatomy

• The hip joint involves the femoral head and acetabulum; vascular supply primarily from the medial femoral circumflex artery.
• The proximal femoral physis and ossific nucleus are critical growth centers influencing femoral head development.

Clinical Presentation

• Redislocation presents as loss of hip stability post-reduction, often with pain, limited motion, or abnormal limb positioning.
• AVN may be asymptomatic initially but leads to limp, pain, and deformity over time.

Imaging

• Redislocation: Confirmed by ultrasound (infants) or X-ray showing displacement of the femoral head.
• AVN: Diagnosed radiographically using serial X-rays; early signs include sclerosis and fragmentation of the ossific nucleus. MRI can detect early ischemic changes.

Classification Systems

| AVN | Kalamchi & MacEwen | Type I: Ossific nucleus involvement only (best prognosis)
Type II: Lateral physis involvement (valgus deformity)
Type III: Central physis involvement (coxa breva)
Type IV: Entire head and physis involvement (severe deformity) | Guides prognosis and treatment planning |

Current Gold Standard Treatment

Non-operative

• Initial management of redislocation after closed reduction involves prompt repeat closed reduction under anesthesia, confirmed by arthrography, followed by spica casting.
• Close monitoring with serial imaging to detect early AVN changes.

Operative Indications and Treatment

• Redislocation after open reduction: Attempt repeat open reduction if soft tissues and skin permit; may require capsulorrhaphy revision.
• AVN management:
• Early intervention focuses on preventing mechanical disadvantage by controlling trochanteric overgrowth.
• Surgical options include growth arrest of the greater trochanter before age 8 or distal transfer of the greater trochanter if overgrowth is established.
• Osteotomies may be necessary for deformity correction in severe cases.

Modern Complications & Outcomes

Complications

Outcomes

• Redislocation is a recognized complication, not necessarily a treatment failure; timely management can restore stability.
• AVN significantly impacts long-term hip function, leading to limp, pain, and early osteoarthritis if untreated.
• Early detection and intervention improve functional outcomes and reduce the need for complex reconstructive surgeries.

Classic Clinical Notes

DDH-Rx complications

Developmental Dysplasia of the Hip – Tx Complications

Redislocation

• Have to be ready for this; this is just a known, recognized complication, not a failure of treatment.
• If redislocates after a closed reduction – immediately perform another closed reduction, arthrography, spica etc.
• If redislocates after an open reduction – this is a bit trickier; if the skin is okay, you can try the open reduction again. Be prepared for the fact that achieving a stable reduction and repeating the capsulorrhaphy may be difficult the second time around.

Avascular Necrosis

• Does not happen in the untreated DDH.
• Highly correlated with forceful reductions of the hip and wide abduction (kinks off the posterior vessels).
• Also associated with damage to the medial femoral circumflex during medial open reduction.
• There are a number of classification systems; Kalamchi/MacEwen – basically, you want to know:
• Does the avascularity involve just the ossific nucleus? These do well.
• Does it involve the lateral aspect of the physis? The femoral head tilts into valgus gradually as medial side grows.
• Does it involve the central part of the physis? Get coxa breva (short neck) but with no change in neck shaft angle.
• Is the whole head/physis complex toast? These develop marked shortening of the neck with varus deformity and trochanteric overgrowth.

• If the physis is dead, a bit of length is lost (most of the femoral growth is at the distal physis) but more importantly have a short neck and trochanteric overgrowth, causing an adductor limp because of the mechanical disadvantage of having an elevated trochanter and short abductors.
• Treatment: either arrest the growth of the greater trochanter before the age 8 (or sometime before the trochanter reaches the level of the femoral head), or if already past, transfer the greater trochanter distally.

Last Updated on January 25, 2026 by orthonet