Patient-specific instrumentation (PSI) in total ankle arthroplasty: a systematic review

Author(s):  
Qiuyuan Wang ◽  
Nianfei Zhang ◽  
Wanshou Guo ◽  
Weiguo Wang ◽  
Qidong Zhang
2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0008
Author(s):  
Ali-Asgar Najefi ◽  
Andrew Goldberg

Category: Ankle Arthritis Introduction/Purpose: Inadequate correction of alignment in the coronal, sagittal or axial planes will inevitably lead to failure of the Total Ankle Arthroplasty (TAA). The mechanical axis of the lower limb (MAL), the mechanical axis of the tibia (MAT) and the anatomical axis of the tibia (AAT) are three recognized coronal plane measurements using plain radiography. The relationship between anatomical and mechanical axes depends on the presence of femoral or tibial deformities from trauma or inherited conditions, or previous corrective or replacement surgery. Ankle arthroplasty relies heavily on preoperative radiographs or CT scans and the purpose of this study was to assess whether MAL, MAT and AAT are the same in a cohort of patients upon which placement of TAA is considered. Methods: We analysed 75 patients operated on between 2015 and 2016 at a specialist tertiary centre for elective orthopaedic surgery. All patients had a pre-operative long leg radiograph. They were split into 2 groups. The first group had known deformity proximal to the ankle (such as previous tibial or femoral fracture, severe arthritis, or previous reconstructive surgery) and the second group had no clinically detectable deformity. The MAL, MAT and AAT were assessed and the difference between these values was calculated. Results: There were 54 patients in the normal group, and 21 patients in the deformity group. Overall, 25 patients(33%) had a difference between all three axes of less than 1 degree. In 33 patients(44%), there was a difference in one of the axes of ≥2 degrees. There was no significant difference between MAT and AAT in patients in the normal group(p=0.6). 95% of patients had a difference of <1 degree. There was a significant difference between the MAT and AAT in patients in the deformity group(p<0.01). In the normal group, 39 patients(73%) had a difference of <2 degrees between the AAT and MAL. In the deformity group, only 10 patients (48%) had a difference of <2 degrees.In fact, 24% of patients had a difference ≥3 degrees. Conclusion: Malalignment in the coronal plane in TAA may be an issue that we have not properly addressed. Up to 66% of patients without known deformity may have a TAA that is placed at least 1 degree incorrectly relative to the MAL. We recommend the use of full-length lower limb radiographs when planning a TAA in order to plan the placement of implants. The decision to perform extramedullary referencing, intramedullary referencing, or patient specific Instrumentation must be part of the pre-operative planning process.


2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0004 ◽  
Author(s):  
Mario Escudero ◽  
Kevin Wing ◽  
Thomas Bemenderfer ◽  
Michael Symes ◽  
Maximiliano Barahona ◽  
...  

Category: Ankle Arthritis Introduction/Purpose: Total ankle arthroplasty (TAA) and ankle arthrodesis (AA) have been standard treatment modalities for end-stage ankle osteoarthritis. Final implant position and successful soft tissue balancing are key components to the longevity of total ankle implants. Patient-specific instrumentation (PSI) has been developed for TAA, with proven cost effectiveness, accurate and reproducible radiographic outcomes and less operative time. However, one concern regarding PSI is the need for more soft tissue dissection in order to accurately position the PSI guides, which has the theoretical disadvantage of increased localized adjacent tissue necrosis that may lead to early osteolysis. As such the purpose of our study is to compare the incidence and magnitude of osteolysis for a low-profile tibia and talar resurfacing implant between PSI and standard referencing (SR) techniques. Methods: The first 67 consecutive patients who underwent primary Infinity total ankle arthroplasty (TAA) at 2 North American sites between 2013 and 2015 were reviewed in a prospective observational study. Demographic, radiographic, and functional outcome data was collected preoperatively, at 6-12 months postoperatively, and annually thereafter. Osteolysis was assessed at two years after TAA, dividing the ankle into eight zones, and then a number was assigned according to lucency magnitude (see Figure) Osteolysis incidence was calculated by a binomial distribution. The number of zones compromised and magnitude of osteolysis was calculated using the median as resume statistic and interquartile range as dispersion statistic. Fisher exact test was used to compare osteolysis presence between groups; then a regression model was estimated to calculate the odds ratio for osteolysis. The comparison of osteolysis magnitude between groups was done with the Chi-squared test. A significance of 5% was used. Results: Of a total of 67 TAAs included, 51 were in the PSI group and 16 in the SRI group. In the PSI group the incidence, the number of compromised zones (CZ) and magnitude was 0.42% (0.25-0.61%), 3 [2-4] and 2[2-4] respectively. In the SR group, the incidence, number of CZ and magnitude was0.36% (0.13-0.65%), 2 [2-2], 4 [2-4] respectively. These differences were not statistically significant (p=0.46, p=0.86, p=0.70). A slightly higher risk of osteolysis was found in the PSI Groups (OR=1.33 [0.36- 4.83]). This difference was not statistically significant (p=0.46). Conclusion: According to our data, PSI is not different to SR in terms of risk, incidence and magnitude of early osteolysis in a low-profile tibia and talar resurfacing implant. We acknowledge that osteolysis is a multifactorial pathology, but these results suggest that the use of PSI does not increase its early occurrence. It appears that the higher rate of soft tissue stripping in the PSI group does not affect osteolysis and implant survival in the short term.


2018 ◽  
Vol 3 (3) ◽  
pp. 2473011418S0004
Author(s):  
Mario Escudero ◽  
Kevin Wing ◽  
Feras Waly ◽  
Thomas Bemenderfer ◽  
W. Hodges Davis ◽  
...  

Category: Ankle Arthritis Introduction/Purpose: The unique anatomy and biomechanics of the ankle joint have made total ankle arthroplasty (TAA) challenging over the past few decades. Final implant position and successful soft tissue balancing are key components to the longevity of total ankle implants. Preoperative computer navigation, templating, and patient-specific instrumentation (PSI) have shown promising results in total ankle replacement with accurate and reproducible radiographic outcomes. Recent data has also suggested that even experienced surgeons benefit from the improved time efficiency of PSI. The purpose of this study is to determine if radiographic outcomes differ between patients undergoing TAA with PSI and those who undergo TAA with standard instrumentation (SI). Methods: The first 67 consecutive patients who underwent primary Infinity total ankle arthroplasty (TAA) at 2 North American sites between 2013 and 2015 were reviewed in a prospective observational study. All TAA’s were performed by one of four fellowship-trained foot and ankle surgeons. Demographic, radiographic, and functional outcome data was collected preoperatively, at 6-12 months postoperatively, and annually thereafter. The radiographic variables measured were the medial distal tibial angle (MDTA), talar tilt angle (TTA), lateral talar station (LTS), sagittal distal tibial articular angle (sDTAA), and the gamma angle. Acceptable intervals for each parameter were selected and TAAs were then categorized as being “correctly aligned” or “not correctly aligned” for all the parameters described. The rate of “correctly aligned” TAA’s was compared between cases with PSI and those with SI. Fisher’s exact test was used to analyze difference by groups. A significance of 5% was used. Results: Of a total of 67 TAAs included, 51 were in the PSI group and 16 in the SI group. No significant statistically differences were found between PSI and NPSI regarding MDTA (p=0.174), LTS (p=0.922), sDTAA (p=0.986), gamma angle (p=0.252) and TTA (p=0.145). We did not find a significant statistical difference in the rate of “correctly aligned TAR” when we compared both groups (p=0.35). Conclusion: This study suggests that both PSI and SI provide accurate and reproducible TAA radiographic alignment when performed by experienced surgeons. In view of previously published data demonstrating high levels of reproducibility for PSI in TAA, these data also suggest that PSI may offer a means for less experienced surgeons to achieve radiographic results similar to those achieved by experienced surgeons. It also suggests that experienced surgeons may not need to use PSI to achieve satisfactory implant alignment, though improved time efficiency with PSI, as demonstrated in other studies, may still be of benefit for experienced surgeons.


2016 ◽  
Vol 38 (4) ◽  
pp. 412-418 ◽  
Author(s):  
Justin Daigre ◽  
Gregory Berlet ◽  
Bryan Van Dyke ◽  
Kyle S. Peterson ◽  
Robert Santrock

2021 ◽  
pp. 107110072199637
Author(s):  
Mario I. Escudero ◽  
Vu Le ◽  
Thomas Bradford Bemenderfer ◽  
Maximiliano Barahona ◽  
Robert B. Anderson ◽  
...  

Background Several benefits are published supporting patient-specific instrumentation (PSI) in total ankle arthroplasty (TAA). This study seeks to determine if TAA with PSI yields different radiographic outcomes vs standard instrumentation (SI). Methods: Sixty-seven primary TAA patients having surgery using PSI or SI between 2013 and 2015 were retrospectively reviewed using weightbearing radiographs at 6-12 weeks postsurgery. Radiographic parameters analyzed were the medial distal tibia angle (MDTA), talar-tilt angle (TTA), anatomic sagittal distal tibia angle (aSDTA), lateral talar station (LTS), and talar component inclination angle (TCI). A comparison of the 2 groups for each radiologic parameter’s distribution was performed using a nonparametric median test and Fisher exact test. Furthermore, TAAs with all radiographic measurements within acceptable limits were classified as “perfectly aligned.” The rate of “perfectly aligned” TAAs between groups was compared using a Fisher exact test with a significance of .05. Results: Of the 67 TAAs, 51 were done with PSI and 16 with SI. There were no differences between groups in MDTA ( P = .174), TTA ( P = .145), aSDTA ( P = .98), LTS ( P = .922), or TCI angle ( P = .98). When the rate of “perfectly aligned TAA” between the 2 groups were compared, there was no significant difference ( P = .35). Conclusion: No significant radiographic alignment differences were found between PSI and SI implants. This study showed that both techniques achieve reproducible TAA radiographic coronal and sagittal alignment for the tibial component when performed by experienced surgeons. The talar component’s sagittal alignment is similar whether or not PSI was used but is noticeably different from normal anatomic alignment by design. Level of Evidence: Level III, retrospective cohort study using prospectively collected data.


2021 ◽  
Vol 6 (4) ◽  
pp. 247301142110614
Author(s):  
Mitchell J. Thompson ◽  
Devon Consul ◽  
Benjamin D. Umbel ◽  
Gregory C. Berlet

Background: Total ankle arthroplasty (TAA) is a popular and viable option for end-stage ankle arthritis. Posttraumatic arthritis is the most common etiology of ankle arthritis, which creates the additional challenge of osseus deformity. Accuracy and reproducibility in placing the implant on the mechanical axis has been shown to be paramount in all joint arthroplasty including total ankle replacement. Patient-specific preoperative navigation is a relatively new technology for TAA, and up until this past year has been based off of nonweightbearing (NWBCT) or simulated weightbearing computed tomography (WBCT). Our institution has created a protocol to use WBCT in the preoperative patient-specific navigation for TAA using the Prophecy system. The purpose of our study was to compare the accuracy and reproducibility of implant alignment and size using WBCT vs prior studies using NWBCT for the Prophecy reports. Methods: All patients from July 2019 through October 2020 who underwent TAA were evaluated. Inclusion criteria consisted of primary TAA using patient-specific preoperative navigation who had postoperative radiographs in the 4-6-week time frame. Prophecy predictions and measurements were then compared to actual implant placement and size. Results: Ten patients met our inclusion criteria of WBCT Prophecy preoperative planning using 2 different implant systems. Preoperative deformities in this cohort were small. The average postoperative coronal alignment was 0.84 degrees, range 0.19 to 2.4 degrees. Average postoperative sagittal plane deformity was 1.9 degrees, range 0.33 to 5.05 degrees. Tibial component size was properly predicted in all patients, talar component in 9 of 10. Conclusion: This initial report supports accuracy and reproducibility in preoperative patient-specific navigation when using WBCT for TAA with these implants. All TAAs were within the intended target of less than 5 degrees varus or valgus. Level of Evidence: Level III, retrospective comparative analysis.


2017 ◽  
Vol 16 (4) ◽  
pp. 183-189
Author(s):  
Guilherme H. Saito ◽  
Austin E. Sanders ◽  
Daniel R. Sturnick ◽  
Constantine A. Demetracopoulos

2019 ◽  
Vol 25 (3) ◽  
pp. 383-389 ◽  
Author(s):  
Guilherme H. Saito ◽  
Austin E. Sanders ◽  
Martin J. O’Malley ◽  
Jonathan T. Deland ◽  
Scott J. Ellis ◽  
...  

2020 ◽  
Vol 5 (4) ◽  
pp. 2473011420S0010
Author(s):  
Pierre-Marc April ◽  
Philippe Hugo Champagne ◽  
Magalie Angers ◽  
Karl-Andre R. Lalonde ◽  
Brad Meulenkamp ◽  
...  

Category: Ankle Arthritis Introduction/Purpose: Ankle arthritis (OA) is a frequent and debilitating disease with the two primary surgical options being ankle arthrodesis or total ankle arthroplasty (TAA). TAA has the advantages maintenance of range of motion (ROM), a more normalized gait and potentially improved functional outcome over arthrodesis. Malaligned protheses have been demonstrated to have increased peak component pressures, potentially leading to component loosening, failure and overall worse outcomes. One TAA system uses pre-op CT to build patient-specific surgical instrumentation, with purported benefit of more reliable and accurate component positioning. The goal of this study is to evaluate reproducibility and accuracy of this system by surgeons without affiliation with the prosthesis design team. Methods: A retrospective radiological study was performed including two centers with four fellowship-trained foot and ankle surgeons using the patient-specific TAA system. All patients operated on between 2015-2018 were included. The primary outcome was alignment of the tibial implant in coronal and sagittal orientation relative to the tibia anatomic axis. All measurements were performed in duplicate an orthopaedic foot and ankle fellow and a musculoskeletal fellowship-trained radiologist. Secondary outcomes included accuracy of prediction of tibial and talar component size implanted compared to the engineered pre-operative plan, rate of prosthesis revision (at least one component) and overall re-operation rate. Results: 79 patients were included in the final review. The mean absolute deviation of the tibial component from tibial anatomical axis was 1.31° +/- 1.14in the coronal plane and 2.68°+/- 1.74 in sagittal alignment. 94.7 % of the implants were implanted within 3°of varus or valgus and 73.7% within 3°of dorsiflexion or plantiflexion. 86 % of the implanted tibial component were of the size predicted by the pre-op plan whereas it was found to be the case in 63 % of the talar component.At a mean follow-up of 22 months(3-52), two TAA (2.5%) have been revised due to aseptic tibial implant loosening. Conclusion: The patient-specific guide has been found to be a reliable system for coronal tibial implant alignment but less in the sagittal plane in the hand of surgeons not involved in the design of any TAA system. Accuracy of prediction of the tibial component size is high, moderate on the talar side. In this series there was a low rate of early component revision (2.5 %).


2019 ◽  
Vol 13 (Supl 1) ◽  
pp. 65S
Author(s):  
Guilherme Honda Saito ◽  
Austin Sanders ◽  
Martin O'Malley ◽  
Jonathan Deland ◽  
Scott Ellis ◽  
...  

Introduction: Correct positioning of implants in total ankle arthroplasty (TAA) is a key step to ensure the longevity of the prosthesis. Patient-specific instrumentation (PSI) via preoperative computed tomography for TAA was developed and made available through PROPHECY (Wright Medical, Memphis, TN). The purpose of this study was to compare the use of PSI with the standard referencing guide (SRG) in regard to the accuracy of tibial implant positioning, operative time, and fluoroscopy time. Methods: A retrospective analysis of 99 patients who underwent a primary TAA with the INFINITY prosthesis (Wright Medical, Memphis, TN) was performed. Patients were divided in two groups based on the type of instrumentation used during the TAA (75 in the PSI - PROPHECY group vs 24 in the SRG group). Results: Tibial implant positioning was similar between groups. In the coronal plane, the absolute deviation of the tibial implant was 1.7 ± 1.4 degrees for the SRG and 1.6 ± 1.2 degrees for PSI (P = 0.710). In the sagittal plane, the absolute alignment deviation of the tibial implant was 1.8 ± 1.4 degrees for the SRG and 1.9 ± 1.5 degrees for PSI (P = 0.675). Operative time (P = 0.040) and fluoroscopy time (P < 0.001) were significantly decreased in the PSI group. The PSI preoperative plan report correctly predicted the implant size in 73% of cases for the tibial component and in only 51% of cases for the talar component. Conclusions: PSI provided similar tibial component alignment to standard instrumentation while decreasing the operative and fluoroscopy time. However, PSI preoperative plan reports were poor predictors of implant sizing. Therefore, the final decision should always be based on the surgeon’s experience to prevent errors in implant sizing and positioning.


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