Patient-specific instrumentation in total ankle arthroplasty

The recent increase in the adoption of total ankle arthroplasty(TAA)reflects the improvements in implant designs and surgical techniques,including the use of preoperative navigation system and patient-specific instrumentation(PSI),such as custom-made cutting guides.Cutting guides are customized with respect to each patient's anatomy based on preoperative ankle computed tomography scans,and they drive the saw intra-operatively to improve the accuracy of bone resection and implant positioning.Despite some promising results,the main queries in the literature are whether PSI improves the reliability of achieving neutral ankle alignment and more accurate implant sizing,whether it is actually superior over standard techniques,and whether it is cost effective.Moreover,the advantages of PSI in clinical outcomes are still theoretical because the current literature does not allow to confirm its superiority.The purpose of this review article is therefore to assess the current literature on PSI in TAA with regard to current implants with PSI,templating and preoperative planning strategies,alignment and sizing,clinical outcomes,cost analysis,and comparison with standard techniques.

Total ankle replacement with INBONE-II prosthesis: A short-to-medium-term follow-up study in China

Background:Total ankle replacement(TAR)is a viable option for the treatment of end-stage ankle arthritis.In China,the INBONE-II implant is the only total ankle prosthesis approved since 2016.The purpose of this study is to report a large sample of findings for the TAR with INBONE-II prosthesis.Methods:A total of 64 patients with end-stage ankle arthritis,who underwent primary TAR using INBONE-II by the same surgeon from 2016 to 2019,at a single institution were included in this retrospective,single-center study.Clinical data,radiographic findings,survival rate,and complications were recorded and assessed pre-operatively and at the most recent follow-up.Results:A total of 64 patients were available for follow-up at least 2 years after surgery;the mean follow-up duration for clinical outcomes was 37.9 months(24–59 months),and for radiographic findings was 22.8 months(12–59 months).There were significant improvements(P<0.01)in the American Orthopedic Foot and Ankle Society hindfoot scale,the visual analog scale for pain,and the Short Form-36.There were statistically significant differences between pre-operative and post-operative comparisons of the talar tilt angle(TT)and the tibial lateral surface angle(TLS)in the radiographic findings(TT from 4.7±4.3°to 1.3±1.3°,TLS from 80.4±7.7°to 87.4±2.3°,P<0.01).There was no statistically significant difference in improvement of the tibial anterior surface angle(P=0.14).Ten complications(all low grade)were recorded according to the Glazebrook classification system.The survivorship of the prosthesis was 100%(64/64).Conclusion:Patients who underwent TAR with INBONE-II prosthesis demonstrated significant improvements in all measures of pain and function as well as in radiographic findings.High survival and a low incidence of complications were observed in this study.