Surgical applications of three-dimensional printing in the pelvis and acetabulum: from models and tools to implants

Abstract

There are numerous orthopaedic applications of three-dimensional (3D) printing for the pelvis and acetabulum. The authors reviewed recently published articles and summarized their experience. 3D printed anatomical models are particularly useful in pelvic and acetabular fracture surgery for planning, implant templating and for anatomical assessment of pathologies such as CAM-type femoroacetabular impingement and rare deformities. Custom-made metal 3D printed patient-specific implants and instruments are increasingly being studied for pelvic oncologic resection and reconstruction of resected defects as well as for revision hip arthroplasties with favourable results. This article also discusses cost-effectiveness considerations when preparing pelvic 3D printed models from a hospital 3D printing centre.

Keywords: 3D printing; Hip replacement; Orthopaedics; Pelvic tumour; Pelvis.

Fig. 1

An example of a digital three-dimensional (3D) model of a posterior wall acetabular fracture in stereolithography format (a). The 1:1-sized 3D printed model allows the surgeon to accurately appreciate fracture morphology (b). A mirrored model is printed using the opposite intact hemi-pelvis for easy and accurate plate contouring (c). Surgical plan after fracture fixation (d). The implants are placed according to the surgical plan after fracture fixation reduction

Fig. 2

Design of a patient-specific drill guide for the placement of bilateral dual iliac screws for a patient with osteogenesis imperfecta undergoing posterior spinal fusion and instrumentation surgery in inlet (a) and posterior (b) orientations

Fig. 3

An example of showing the location and simulating mechanical femoroacetabular impingement in a 12-year-old patient. The offending CAM-type lesion is accurately located before osteochondroplasty, marked (a, b) and seen in surgery (c)

Fig. 4

A 15-year-old patient with a malunited acetabulum posterior wall with hip subluxation (a). Digital model (green) compared to the mirrored opposite (red) (b). A closing-wedge volume-reducing osteotomy is planned (c) with 3D printed cutting jig (d, e). Postoperative computed tomography showing satisfactory restoration of hip congruency (f)

Fig. 5

Patient with Paprosky IIIa defect and acetabular component loosening (a). Planning is performed using a digital three-dimensional model (b). Custom-made porous titanium alloy acetabular component printed using direct metal laser sintering (c). Intraoperative use of patient-specific instrumentation placed Schanz screws as positional references for implant (d) and reamer (e) placement. Postoperative computed tomography scan confirming satisfactory positioning (f)

Fig. 6

A 39-year-old patient with right acetabulum chondrosarcoma resection, reconstructed with an electron-beam melting three-dimensionally printed porous modular hemi-pelvic endoprosthesis (a) with preoperative virtual planning (b). Radiograph at 2 years (c), with computed tomography showing osteointegration (d)

Fig. 7

Using a fused deposition modelling (FDM) system at a 0.01-in. layer thickness (Fortus 450mc, Stratasys, Eden Prairie, MN, USA). Printing only the relevant fractured acetabulum results in 78% savings in materials and 76% savings in printing time compared to the whole pelvis