Early Outcomes of Total Hip Arthroplasty Using Point-of-care Manufactured Patient-specific Instruments: a Single University Hospital’s Initial Experience

AbstractBackground 3D printed patient-specific instruments (PSI) have been recognized as a novel solution for the optimal orientation of hip implant components and were explored to improve the postoperative functional outcomes in total hip arthroplasty (THA). The manufacturing of PSI is gradually moving towards point-of-care production. This article aims to evaluate the accuracy and safety of PSI for total hip arthroplasty produced point-of-care in Vietnamese university hospital. Methods This prospective study evaluated 34 cases of THA. Preoperative 3D computed tomography (CT) scanning of the lower limb was collected to create a template for the implant size, orientation, and design of the PSI. The position of the implants and PSI design were determined directly on the software by the main surgeon. 3D-compatible resin printers were used to create the PSI in manufacturing hospital. The PSI consists of an acetabulum and a femoral component placed press-fit on the bony surface. The PSI then guided surgeons to ream the acetabulum and cut the femoral neck precisely according to the pre-planned plane. Postoperative CT scanning was obtained and superimposed onto the 3D model of the implant to evaluate the outcome. Intraoperative clinical parameters of surgical safety were also recorded. Results The preparation for PSI required an average of three days. 94% of cup size and 91% of stem size were correct. The mean values of postoperative inclination and anteversion were 44.2° ± 4.1° and 19.2° ± 5.6°, respectively. 64.7% of cases deviation from planned within ± 50range and 94.1% within ± 10° range. The means of stem anteversion, osteotomy height, and leg length discrepancy did not have a statistically significant difference between planned and achieved (p > 0.05). The average surgical time was 82.5° ± 10.8 minutes, and the intraoperative blood loss was estimated at 317.7° ± 57.6ml. 64.7% patients can walk on day of surgery. There were no complications reported. Conclusions The point-of-care manufactured PSI is a useful solution for improving the accuracy of total hip arthroplasty surgery, especially in restoring the implant orientation and reducing leg length discrepancy. However, long-term clinical follow-up evaluation is needed to confirm the efficacy and safety of this approach.