3D Printed Patient-Specific Acetabular Jig for Cup Placement in Total Hip Arthroplasty

Abstract

Introduction Acetabular cup placement is an important modifiable factor determining complication rates like aseptic loosening and hip dislocation related to faulty cup placement, which by standard method is largely dependent upon eyeballing and surgeon's judgment. We evaluated a self-designed, low-cost, patient-specific acetabular jig to guide cup placement in total hip arthroplasty in comparison to conventional technique. Methods It was a prospective randomized control study. Thirty-six patients were categorized into group-A & group-B. In group-A, virtually designed acetabular jig was 3 Dimensional (3D) printed and used intra-operatively to guide cup placement. In group-B, the standard method of cup placement was used. Acetabular cup placement was evaluated on postoperative x-rays and compared between two groups. Results In group-A, angle of anteversion were significantly in centre of range of safe zone as compared to group B in which hip is maximally stable with more precision in creating hip centre as compared to group-B without any significant(p = 0.325) increase in surgical time or blood loss. Conclusion Computed tomography (CT) scan based virtual pre-operative templating and cup placement guided by virtually designed, patient-specific acetabular jig is a low-cost tool with a short learning curve which can be designed and made available easily. It is a useful tool in decreasing chances of malpositioning of cup and recreates hip centre close to anatomical one especially in cases where anatomy has been distorted such as bony ankylosis and developmental dysplasia of hip.

Application of 3D Printing in Hip and Knee Arthroplasty: A Narrative Review

“…They concluded that such instrumentation allowed more accurate placement of the acetabular component in terms of achieving preoperative patient-specific target inclination and anteversion, with minimal deviation, than free-hand methods used in a previously reported different control group of 188 THRs. The most recent study published in 2020 by Mishra et al further confirms that using a 3D-printed guide jig to place the acetabular cup provides better anteversion than conventional methods [23]. Additionally, the difference in duration of surgery and blood loss in both the methods were insignificant implying that no additional time was wasted.…”

“…15 out of 30 studies discuss 3DP in hip replacements, with 7 studies related to customised components [12][13][14][15][16][17][18], and 6 related to patient-specific instrumentation and positioning guides [19][20][21][22][23][24]. One study assessed the role of preoperative planning as well as usage of 3DP acetabular components [25].…”

“…One study focused on diagnostic accuracy of 3DP models in pelvic discontinuity [26]. Five studies were retrospective in design [12-14, 20, 26], while 1 3 ten studies were prospective [15][16][17][18][19][21][22][23][24][25]. 14 out of 15 studies related to 3DP and hip arthroplasties have been published between 2014 and 2020, demonstrating that 3DP is a very recent addition to the armamentarium of Hip arthroplasty surgeons (Table 1).…”

“…Six studies assessed the benefits of patient-specific instrumentation in hip arthroplasty [19][20][21][22][23][24]. Small et al did an RCT comparing THA with PSI and conventional surgeries.…”

Orientation of Transverse Acetabular Ligament With Reference to Anterior Pelvic Plane

“…Navigated THA is believed to offer better results with cup positioning and reduce the number of outliers [ [26] , [27] , [28] ]. Computer navigation, patient-specific jigs [ 29 ], and robotics have all been developed to aid accuracy but are still not commonly used. Most surgeons use conventional techniques because of the learning curve, time, and resource constraints.…”