How 3D patient-specific instruments improve accuracy of pelvic bone tumour resection in a cadaveric study

Abstract

ObjectivesTo assess the accuracy of patient-specific instruments (PSIs) versus standard manual technique and the precision of computer-assisted planning and PSI-guided osteotomies in pelvic tumour resection.MethodsCT scans were obtained from five female cadaveric pelvises. Five osteotomies were designed using Mimics software: sacroiliac, biplanar supra-acetabular, two parallel iliopubic and ischial. For cases of the left hemipelvis, PSIs were designed to guide standard oscillating saw osteotomies and later manufactured using 3D printing. Osteotomies were performed using the standard manual technique in cases of the right hemipelvis. Post-resection CT scans were quantitatively analysed. Student’s t-test and Mann–Whitney U test were used.ResultsCompared with the manual technique, PSI-guided osteotomies improved accuracy by a mean 9.6 mm (p < 0.008) in the sacroiliac osteotomies, 6.2 mm (p < 0.008) and 5.8 mm (p < 0.032) in the biplanar supra-acetabular, 3 mm (p < 0.016) in the ischial and 2.2 mm (p < 0.032) and 2.6 mm (p < 0.008) in the parallel iliopubic osteotomies, with a mean linear deviation of 4.9 mm (p < 0.001) for all osteotomies. Of the manual osteotomies, 53% (n = 16) had a linear deviation > 5 mm and 27% (n = 8) were > 10 mm. In the PSI cases, deviations were 10% (n = 3) and 0 % (n = 0), respectively. For angular deviation from pre-operative plans, we observed a mean improvement of 7.06° (p < 0.001) in pitch and 2.94° (p < 0.001) in roll, comparing PSI and the standard manual technique.ConclusionIn an experimental study, computer-assisted planning and PSIs improved accuracy in pelvic tumour resections, bringing osteotomy results closer to the parameters set in pre-operative planning, as compared with standard manual techniques.Cite this article: A. Sallent, M. Vicente, M. M. Reverté, A. Lopez, A. Rodríguez-Baeza, M. Pérez-Domínguez, R. Velez. How 3D patient-specific instruments improve accuracy of pelvic bone tumour resection in a cadaveric study. Bone Joint Res 2017;6:577–583. DOI: 10.1302/2046-3758.610.BJR-2017-0094.R1.

A Cadaveric Comparative Study on the Surgical Accuracy of Freehand, Computer Navigation, and Patient-Specific Instruments in Joint-Preserving Bone Tumor Resections

“…On the contrary, if the mass is problematic for the PSI, it will be problematic for the cutting whatever the method used. Also, clinical data on pelvis have shown comparable results [ 7 , 30 ]. Third, the sample size was small.…”

Sacroiliac joint cut accuracy: Comparing new technologies in an idealized sawbones model

“…When the 5 mm acceptability criterion was applied ( 18 Other cadaver studies demonstrated that custom-made jigs improved accuracy in multiple resection planes 16 and provided less cut deviation. 17 Outcomes contrasting computerized navigation and patientspecific guided procedures to the freehand technique have been reported in other orthopaedic subspecialties 23,24 ; however, we believe that our study is the first to compare all three for SI joint tumor resections.…”

“…7 Basic science and clinical studies have shown better adherence to predetermined margins as well as other results with the aid of PSI devices. 11,[14][15][16][17][18] The lack of any gold standard cutting method encouraged us to investigate: (1) Does freehand, computerized navigation, or the patientspecific cutting guide technique achieve the most accurate planned cut in a Sawbones model? (2) Which technique causes the least far-side damage to pelvic viscera and important neurovascular structures beyond the resection margins?…”

Surgical management of metastatic lesions of proximal femur and the hip

“…This reconstruction method is durable but with inherent risks of infection and dislocation. Introduction of computer based navigation and patient specific instrumentation has the potential to increase accuracy of tumor resection and decrease the incidence of implant-specific complications [ [48] , [49] , [50] ]. Poor cancer status, timing, estimated life expectancy and available surgical expertise should be considered in the choice of surgical strategy to optimize the outcome of surgery in these patients.…”