In 2005 a 78-year-old woman was admitted with an undisplaced proximal femoral fracture and was operated with osteosynthesis by 2 hip pins (Smith and Nephew, Tuttlingen, Germany). Postoperatively, she was allowed full weight bearing and left hospital 14 days later. At first follow-up, 8 weeks after surgery, the patient walked with an ambulatory device and admitted that she had some pain. The radiographs showed a displaced fracture (Figure 1A-C). The patient was informed about possible prognosis outcome, but she was satisfied with the progress thus far and refused any kind of further treatment at this point.
Follow-ups at 5 and 8 months revealed further displacement of an unhealed fracture. The patient was still not motivated to have further treatment, and no additional follow-up was planned.
In June 2011, the patient felt moderate anal discomfort. During defecation the following day, she experienced pain and needed aid from her home-based nurse to extract a foreign body which slipped into the toilet bowl with a metallic sound. With suspicions about the origin of the screw, it was presented to the patient’s GP and she was admitted to our outpatient clinic for further investigation.
The patient was completely asymptomatic in the abdomen, and her anal discomfort had disappeared. The radiograph (Figure 1D) revealed only 1 remaining hip pin and the screw presented to us was confirmed to be identical to the missing distal screw implanted in the patient’s left hip 6 years earlier. The fracture was greatly displaced, with no sign of healing and the remaining screw was still in situ; it was displaced, but without any major migration. The skin showed no recent scars or signs of perforation.
To avoid further complications, including pelvic migration, the remaining screw was easily removed percutaneously under local anesthesia. In order to reveal any possible intrapelvic damage, and at the same time hoping to track the pathway of the migrated screw, we performed a CT scan (Figure 2A-C) with 3D reconstructions (Figure 3A and B). The CT scans left no doubt regarding the pathway of the screw. The femoral head was perforated with a canal similar to the diameter of the screw and there was a crater in the pelvic bone located in line with the perforation through the femoral head. There was no sign of bowel perforation, but some scar tissue was located between the rectum and the crater surrounding the pelvic perforation. The location of the scar tissue and the pelvic bone perforation indicated a migration into the extraperitoneal part of the colon.