A Case Report of Pipkin Type II Femoral Head Fracture Managed by Ganz Safe Surgical Dislocation and Headless Compression Screw (Herbert Screw) Fixation: A Stepwise Technical Description and Clinical Outcome

Posterior hip dislocation with a concurrent shear fracture of the femoral head is an uncommon high-energy injury, and when the displaced fragment involves the weight-bearing dome cranial to the fovea capitis, anatomical reduction is essential to preserve joint kinematics and reduce the risk of late avascular necrosis and post-traumatic arthritis. We describe a 23-year-old male motorcyclist who sustained an isolated right posterior hip dislocation with a Pipkin Type II fragment of the superomedial femoral head. Closed reduction was achieved within four hours of injury (total time from injury to definitive reduction was 3 hours and 40 minutes, within the recognised six-hour vascular-protective window). Post-reduction computed tomography characterised a non-comminuted suprafoveal fragment measuring 22 × 18 mm, with an intact femoral neck and acetabulum. Definitive open reduction and internal fixation were performed via a Kocher-Langenbeck approach with Ganz trochanteric flip osteotomy. The fragment was anatomically reduced and secured with three Herbert headless compression screws - two of 4 mm × 18 mm placed antegrade from the articular surface of the fragment into the parent femoral head in a divergent configuration, and one of 4 mm × 24 mm placed retrograde from the parent head as a supplementary lag screw - all three screws crossing the fracture line. The trochanteric osteotomy was refixed with three 3.5 mm cortical screws. At 12 months postoperatively, the patient was pain-free, ambulating without aids, and had returned to his previous level of activity, with a Harris Hip Score of 98, a modified Merle d'Aubigné-Postel score of 17, a Tönnis grade of 0, and no radiographic evidence of avascular necrosis of the femoral head or heterotopic ossification. Surveillance is continuing in view of the recognised possibility of late-onset avascular necrosis presenting two to five years following injury. This report provides a stepwise technical description of the Ganz surgical hip dislocation combined with a divergent antegrade plus retrograde lag headless compression screw construct for isolated Pipkin Type II fixation, intended to complement existing series-level literature with reproducible operative detail.