Revision Hip Arthroplasty Case Title: Acetabular Impaction Grafting

Case Title: Acetabular Impaction Grafting

 

 

1. Demographics

    

   Age: 78 Sex: female BMI: 28

    

2. Relevant Past Medical History

    

   Principal pathologies: high blood pressure.

   Previous surgical procedures: cemented total hip replacement right side 1986 due to primary osteoarthritis.

   Medication: enalapril.

   History of presenting complaint: groin pain which requires daily oral analgesics and the use of a cane for walking outdoors during the last six months.

    

3. Clinical Examination

    

   Symptoms: groin pain during everyday activities. Evident limp which requires the use of a cane. Difficulty putting on her shoe.

   Range of motion: flexion of the right hip is limited to 70°, internal rotation is abolished, and the abduction of the hip is only 10–15°.

   Specific tests: positive straight leg raising.

   Main disability: walking restriction.

   Scoring: 2-3-3 Merle-D’Aubigne and Postel scale.

   Neurovascular evaluation: normal.

    

4. Preoperative Radiological Assessment/Imaging

   (Fig. 18.15)

    

    

    

   Fig. 18.15 Loosened cemented right hip with an acetabular bone defect larger than 30%

5. Preoperative Planning

    

   Diagnosis: loosened cemented cup with a large acetabular bone defect Paprosky type 3A (Fig. 18.15).

   Possible treatment options: extra-large uncemented cup, cage reconstruction, acetabular impaction bone grafting.

   Chosen treatment method: acetabular impaction bone grafting.

   Selection of implants if applicable and rational: rim and medial metallic mesh fixed with screw for uncontained defect and morselized bone allograft and a cemented cup.

   Expected difficulties: large segmental bone defects after removal of the previous implant.

   Strategies to overcome difficulties: use of metallic meshes.

    

6. Surgical Note

    

   Patient’s position: Lateral decubitus.

   Type of anaesthesia: spinal.

   Surgical approach: posterolateral.

   Main steps: previous approach, removal of the debris, the fibrous tissue and the loosened implant. The stem is fixed.

   Reconstruction techniques: fixation of both metallic meshes to the rim and medial wall, morselized bone allograft chips from two frozen femoral heads with size range 0.7–1 cm made by rongeur, impaction using appropriate instrumentation X-change (Stryker) and cementation of a contemporary cup 50 mm using antibiotic-loaded gentamicin cement (Palacos) (Figs. 18.16 and 18.17).

    

7. Intraoperative Challenges

    

   Challenges and solutions: convert an uncontained defect to a contained acetabular bone defect.

   Unanticipated problems and solution: large segmental defects, use of metallic meshes.

   Thorough description of decision making, including the reason for the final decision: the planned surgery was finally done after removal of the previous implant and fibrous tissue.

    

8. Postoperative Radiographs

   (Figs. 18.16 and 18.17)

    

    

    

   Fig. 18.16 Restoration of the hip rotation centre after acetabular impaction bone grafting and a cemented cup with the use of two metallic meshes

    

    

    

    

   Fig. 18.17 No signs of loosening four years after surgery. Trabecular remodelling changes can be observed

    

9. Postoperative Management

    

   Chemoprophylaxis and anticoagulant treatment period: subcutaneous low-weight molecular heparin during six weeks.

   Gait/limb loading until full loading: partial toe-touch weight bearing during eight weeks and use of a cane thereafter. The patient still use the cane outdoors for long walking distances.

10. Follow-Up

    and Complications

     

    Scoring: 6-5-5 Merle-D’Aubigne and Postel scale

     

11. Discussion [10, 20, 25]

 

Advantages of the applied method: restoration of the hip rotation centre and bone stock after converting and uncontained defect to a contained cavitary defect.

Disadvantages of the method: large segmental rim acetabular defects.

Alternative evidence-based techniques for the case: trabecular augments combined with acetabular impaction bone grafting.

Why is the chosen technique better for this case: after stabilization of segmental defect with the use of meshes, bone allograft form femoral heads allows to restore bone stock.

Indications and contraindications for your technique: moderate and severe acetabular bone defects without pelvic discontinuity.

Learning curve and how to manage complications: stabilization of segmental defects before doing impaction, especially on the rim. According to Nijmegen recommendations, the use of meshes can convert an uncontained defect to a cavitary bone defect. The principles of using large bone chips of around 1 cm and firm impaction are critical to the success of the technique. Larger segmental bone defects of the roof of the acetabulum remain challenging even with the use of a lateral mesh, so the newer lateral trabecular augmentations in combination with impaction bone grafting may help to solve this problem.

Level of evidence concerning the superiority of this method against others: long-term results from the original group and other independent series around the wor