Acetabular reconstruction after advanced acetabular metastasis resection: Modified Harrington technique with a Kerboull reinforcement device.

The surgical treatment of acetabular bone metastases rests on total hip arthroplasty (THA). In the event of major bone defects, the reconstruction may prove challenging. Two complicating factors are the need to obtain a mechanically stable acetabulum and the unfeasibility of using an autograft to increase the bone stock. The technique described in 1981 by Harrington involves implanting steel rods to reinforce the pelvis before sealing the prosthetic cup. We have now been using this technique for several years, and based on our accumulated experience we introduced several substantial modifications. The most important among them is the use of a Kerboull acetabular reinforcement device (KARD) in addition to the iliac pins. This reinforcement of the acetabulum, which is widely used for THA, serves as the basis for guiding the reconstruction, while also facilitating the sealing of the prosthetic cup. Furthermore, we use centrally threaded rods to avoid secondary displacement. Finally, we routinely use a dual-mobility cemented cup to decrease the risk of dislocation. Here, we describe our acetabular reconstruction technique based on a modified Harrington technique, which is used for acetabular reconstruction in patients with advanced acetabular metastases managed at our French referral centre.

Validity and Reliability of Intraoperative Radiographs to Assess Leg Length During Total Hip Arthroplasty: Correlation and Reproducibility of Anatomic Distances.

BACKGROUND: Leg length discrepancy after total hip arthroplasty is a frequent complication. The aim of this study was to assess the validity (correlation) and reproducibility (inter-rater agreement) of various intraoperative hip radiographs measures to estimate leg length. METHODS: Patients were included if they were aged 15 years or older; were eligible for a total hip arthroplasty, and were operated in lateral recumbent. An intraoperative hip radiograph was performed with the definitive implants in place. At 6 weeks postoperatively, anteroposterior pelvis radiograph was taken. We used 3 measures to assess leg length: the height from the ischial tuberosity to the lesser trochanter (LTI), the height from the center of femoral head to the greater trochanter (GTC), and to the inferior teardrop (TC). RESULTS: The study group consisted of 71 hips with an average age of 69 years (range, 24-92 years). The correlation was 0.545 (95% CI: 0.35-0.69) for GTC, 0.75 (95% CI: 0.61-0.84) for TC, and 0.70 (95% CI: 0.56-0.80) for LTI. Intraoperative and postoperative measures were statistically different for GTC (<0.0001) and TC (<0.0001), and not significant for LTI (P = .06). Reproducibility of these measures were excellent with intraclass correlation coefficients of 0.977, 0.814, and 0.983 for the GTC, TC, and LTI, respectively. CONCLUSION: None of the parameters used to assess leg-length based on an intraoperative radiograph showed good correlation with the postoperative radiograph.

The linea aspera as a rotational landmark: an anatomical MRI-based study.

PURPOSE: The linea aspera can be used as a landmark to assess the rotation of the distal femoral epiphysis when performing an endoprostheses. However, no study has assessed the reliability of this landmark. We therefore asked whether the linea aspera could be used as a rotational landmark for positioning distal femoral knee megaprostheses. MATERIALS: This is an anatomic MRI-based study of 50 femurs (27 subjects). For each femur, multiple axial sections were obtained from the intercondylar line at the knee joint to the lesser trochanter; each axial section was superposed with that where the posterior condyles were seen and the R angle was measured. The R angle is the angle measured medially where the line passing through the linea aspera and the line tangent to the posterior condyles intersects. RESULTS: There were considerable differences between and within subjects with a maximum R angle ranging from 100° to 120°. Regression models showed that the R angle was significantly associated with distance from knee joint and subjects. CONCLUSION: Surgeons should have the R angle measured before performing a distal femoral reconstruction.

The Induced Membrane Technique for Bone Defects of Critical Size After Infection in Children: A Report of 3 Consecutive Cases.

CASE: We report 3 consecutive cases of bone defects of critical size after chronic osteomyelitis in children that were treated with the induced membrane technique, in 2 girls and a boy 7 months to 7 years old. All defects were diaphyseal. The length of resection was from 4 to 12 cm (35% to 55% of the total bone length). Resection of the infected bone, filling of the defect with a cement spacer, and intramedullary fixation were followed by autologous bone-grafting 60 to 90 days later. All defects healed. At the latest follow-up, which ranged from 21 months to 6 years, no recurrence or complication had occurred. CONCLUSION: The induced membrane technique is an attractive option for bone defects of critical size after chronic osteomyelitis in children.