case_images: PMC11723720_01
case_images: Pre-operative AP pelvis. These images are the first AP pelvis X-rays performed for this patient during his initial presentation to the emergency department. Several interesting findings can be seen in these initial radiographs. First, we note the significant amount of heterotopic ossification in the left hip (Brooker stage 3). This is depicted by the red arrow and we note the formation of bony islands originating from the proximal femur and pelvis reducing the space between opposing bone surfaces to <1 cm. Secondly and most obviously is the head-stem dissociation between the trunnion of the Exeter v40 stem and the large metal head of the MITCH TRH system. Finally, we note evidence of loosening of the femoral stem; however, this is better appreciated in Figure 2.
case_images: JOCR-15-116-g001.jpg
case_images: PMC11723720_01_JOCR-15-116-g001.jpg
case_images: F1
case_images: X-rays, MARS scan, laboratory tests (Full blood count, renal profile, C-reactive protein, coagulation profile, metal ion levels), and electrocardiogram, were ordered. X-rays (Figs. 1 and 2) revealed head-stem dissociation in a MoM hip configuration.
case_images: Pre-operative lateral left hip. This is the first lateral X-ray performed for this patient during his initial presentation to the emergency department. It was taken at the same time as Fig. 1. This X-ray provides an alternative view of the head/stem dissociation and also displays the extent of the femoral stem and better shows evidence of femoral stem loosening . The red arrow points to an area of thin (approx. 1 mm) periprosthetic lucency at the implant-cement interface and the green arrows point to areas of lucency (approx. 2 mm) at the cement-bone interface. Both of these findings, in this clinical scenario, are indicative of loosening. This was confirmed intraoperatively during femoral stem extraction.
case_images: JOCR-15-116-g002.jpg
case_images: PMC11723720_01_JOCR-15-116-g002.jpg
case_images: F2
case_images: X-rays, MARS scan, laboratory tests (Full blood count, renal profile, C-reactive protein, coagulation profile, metal ion levels), and electrocardiogram, were ordered. X-rays (Figs. 1 and 2) revealed head-stem dissociation in a MoM hip configuration.
case_images: Pre-operative magnetic resonance image with metal artifact reduction sequence. These are 2 images (top-axial, bottom coronal) taken from a metal suppression magnetic resonance imaging scan done pre-operatively. Although difficult to see due to artifact significant soft-tissue reaction and pseudotumor is visible on both axial and coronal views. The red arrows depict a well-demarcated pseudotumor adjacent to the proximal femur on both the axial and coronal views. The green arrows point to metal debris (low signal intensity) within the pseudotumor on both axial and coronal views.
case_images: JOCR-15-116-g003.jpg
case_images: PMC11723720_01_JOCR-15-116-g003.jpg
case_images: F3
case_images: A MARS scan was conducted which revealed a subfascial 7cm x 7 cm x 10 cm collection posterior to the THA (Fig. 3.)
case_images: Intraoperative photograph during 1st stage revision. This image was taken during the first stage of the revision after dissection through the subcutaneous tissue and fascia. The metallosis and soft-tissue reaction is clearly visible with the green arrows pointing to the dark grey/black metallic debris deposited into the soft tissue and removed partially by the sterile gauze.
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case_images: PMC11723720_01_JOCR-15-116-g004.jpg
case_images: F4
case_images: Extensive metallosis was noted covering muscle and fascial tissue (Fig. 4) which was carefully debrided during the surgery.
case_images: Explanted components and visible trunnionosis and corrosion of femoral stem. This image shows all original components that were explanted during the 1st stage revision. The extent of the corrosion on the stem as well as wear of the trunnion is clearly visible in this image. The metal head and acetabular cup are included for completeness however signs of obvious wear are not clearly visible in these images.
case_images: JOCR-15-116-g005.jpg
case_images: PMC11723720_01_JOCR-15-116-g005.jpg
case_images: F5
case_images: Examination of the stem revealed asymmetrical wear patterns of the trunnion and oxidation of the neck and body of the stem (Fig. 5).
case_images: Immediate post-operative X-ray after 2nd stage revision. This image was taken in the recovery area of the operating theatre right after the 2nd stage revision. Visible in this X-ray are the new components; the cemented Exeter V40 femoral stem, the ceramic head, and the Trident Hemispherical Uncemented cup.
case_images: JOCR-15-116-g006.jpg
case_images: PMC11723720_01_JOCR-15-116-g006.jpg
case_images: F6
case_images: Trident Hemispherical Uncemented cup with 36 mm 10  eccentric insert) were implanted (Fig. 6).