Patient-Specific Instrumentation vs Standard Referencing in Total Ankle Arthroplasty: A Comparison of the Radiologic Outcome

Abstract

Background: Existing literature on the superiority of patient-specific instrumentation (PSI) in total ankle arthroplasty (TAA) over standard referencing (SR) is limited. Advantages presented include better implant alignment, shorter operating times, and increased accuracy of implant size prediction. The aim of this retrospective study was to analyze PSI in the hands of an experienced foot and ankle surgeon new to both PSI and SR for this specific implant, in regard to determining implant alignment, operative times, and radiologic short-term outcome and predicting implant size for tibial and talar components. Methods: Twenty-four patients undergoing TAA using PSI were compared to 25 patients using SR instrumentation. Outcome measures included alignment of the tibial component (α coronal plane, γ sagittal plane), the tibiotalar tilt (β), and the talar offset x on the sagittal view as well as the presence of radiolucent lines, operation time, and wound healing. Postoperative outcome was assessed at 6 weeks, 4 months, and 1 year postoperatively. Results: Implant positioning was similar in both groups, and no advantage in regard to the operative time could be seen when comparing TAA using PSI to SR. Implant size prediction was more reliable for the tibia than for the talus. Three patients (1 from the SR group and 2 from the PSI group) showed radiolucent lines around the tibial component. Two patients (both SR group) suffered delayed wound healing, albeit not requiring any additional measures. Conclusion: The PSI method did not show an advantage over SR in regard to positioning of the components or the duration of the surgery. The current study suggests that no initial advantage of PSI over SR are to be expected in standard total ankle replacement. Level of Evidence: Level III, retrospective study.

Accuracy of a Patient-Specific Total Ankle Arthroplasty Instrumentation

“…32 In a study comparing the use of PSI to a standard referencing guide (SRG), although no significant difference was found in tibial implant alignment, the PSI had significantly less operative and fluoroscopy time. 35 In contrast, the study by Heisler et al 25 showed that implant positioning was similar in both groups, and no advantage in regard to the operative time could be seen when comparing TAA using PSI to SRG.…”

Robotic Technology in Foot and Ankle Surgery: A Comprehensive Review

“…Limitations of CAS, such as in systems like the 3D CT O-Arm TM, include high cost, long operative time, and difficult justification of its use for more streamlined procedures where accuracy, triangulation, or trajectories are not difficult to achieve by the surgeon alone. PSI is also limited due to lack of data on longitudinal outcomes, and mixed results regarding implant position accuracy and fluoroscopy exposure [ 53 , 54 , 55 ]. Lastly, despite the precision offered by the future of robot-assisted TAA, there will be requirements for surgical flexibility as ankle pathology and biomechanical complexity frequently necessitates additional procedures such as MDCO for improved implant function, which could entail a higher economic burden and need for robot complexity [ 59 ].…”

“…Postoperative radiographic assessments of PSI have demonstrated reliable implant positioning (within 3–5 degrees deviation from planned), consistent neutral alignment (93.2–100%), and accurate component sizing (more accurate for tibial than talus component due to intraoperative variation in gutter debridement). However, small comparative studies between standard referencing (SR) and PSI, have found no significant improvements in implant positioning and mixed findings on other proposed benefits such as shorter operative length due to less fluoroscopy required with PSI [ 53 , 54 , 55 ]. As differences in longitudinal outcomes with PSI have also yet to be characterized, the current literature does not provide adequate evidence for widespread adoption of PSI in TAA to justify cost [ 52 , 56 , 57 ].…”

What’s New in Foot and Ankle Surgery

“…Positive outcomes of custom 3-D printed implants and instrumentation for ankle and hindfoot reconstruction have been reported. In a comparison of 24 ankle arthroplasty cases with patient-specific instrumentation and 25 cases with standard instrumentation, Heisler et al 37 found no difference between the techniques for component position or duration of the surgical procedure. All cases were performed by a single, experienced surgeon.…”