Impaction Injury of the Femoral Head After Traumatic Posterior Hip Dislocation: A Literature Review and Case Study.

Background: Femoral head impaction injuries, sometimes referred to as the "Hill-Sachs lesion" of the femoral head, are an uncommon yet significant consequence of posterior hip dislocations. These occur due to compressive forces on the femoral head, frequently compromising vascular supply and predisposing patients to avascular necrosis (AVN), secondary osteoarthritis, and persistent pain. Current literature on their incidence, diagnostic strategies, and treatment remains sparse, with no prior systematic reviews available. Methods: A systematic search of PubMed, Embase, Scopus, Web of Science, and Google Scholar identified 600 records, with 20 additional articles retrieved through manual searching. Following duplicate removal and eligibility screening, 30 studies met inclusion criteria. Included studies involved human subjects with femoral head impaction injuries and provided data on epidemiology, diagnostic modalities, therapeutic interventions, or clinical outcomes. Case Report: A 43-year-old woman presented five months after a posterior hip dislocation with ongoing pain and restricted hip flexion. Initial imaging failed to detect an anterior femoral head impaction fracture. Subsequent MRI revealed a deeply impacted fracture with associated posterior labral detachment. A posterior capsulo-labral repair was performed, while the stable femoral head fracture was managed conservatively.The patient achieved complete resolution of pain and restoration of function postoperatively. At one-year follow-up, radiographs demonstrated concentric reduction and preserved joint congruity. Conclusion: Femoral head impaction injuries demand early recognition using advanced imaging, as conventional radiographs may overlook subtle lesions. Stable fractures may be managed non-operatively, whereas unstable or engaging injuries often require surgical repair. Tailored treatment strategies are critical for optimizing hip function and reducing long-term complications such as AVN and osteoarthritis.