Table 1.

Indications, Contraindications, and Technical Pearls for Inside Out Bone Grafting of Acetabular Intraosseous Cysts

Indications

• Symptomatic hip instability or femoroacetabular impingement (FAI) with magnetic resonance imaging (MRI) and or computed tomography (CT) evidence of an acetabular intraosseous cyst

Contraindications

• Coxarthrosis (Tonnis grade 3 or 4)—Consider total hip arthroplasty

Technical pearls

• Use a blunt probe to gently expose the cyst by manipulating overlying delaminated articular cartilage

• Take time to completely excise the membranous cyst lining to prevent recurrence and failure of bony healing

• Use the portal that gives the best trajectory for delivering bone graft

• Perform grafting in stages and use multiple loads, if necessary, to adequately pressurize cyst

• Meticulously lavage and suction excess bone graft material from the joint

• Appropriately address all underlying pathomechanical contributors to cyst formation including femoroacetabular impingement and dysplasia

Potential risks

• Extravasation of bone graft material, possibly resulting in heterotopic ossification (HO)