Computer assisted surgery (Abingdon, England) 2021 Dec

Authors: Massé V

Abstract
X-Atlas™ is a new imaging technology intended to advance the state of the art in patient-specific instrumentation. It uses standard AP and lateral radiographs instead of CT or MRI scans to create 3D bone models, which can be used to perform pre-operative surgical planning and fabricate TKA personalized guides. The aim of this study was to validate X-Atlas™ and evaluate the accuracy of personalized guides created with this imaging technology. Its ability to predict implant size was also determined. The accuracy of the X-Atlas™ imaging technology was evaluated by comparing the landmarks of X-Atlas™ 3D Bone models to MRI-reconstructed bone models. The accuracy of PSI guides created with X-Atlas™ (X-PSI™ guides) was evaluated during a validation study (16 specimen knees) and a clinical study (50 patients; Health Canada #CSU2015-12K). Optical navigation was used to measure positioning accuracy. In addition, the ability of X-Atlas™ to predict implant size was assessed. The accuracy of the X-Atlas™ imaging technology was below 0.87 and 1.28 mm for the femoral and tibial landmarks, respectively. The accuracy of X-PSI™ guides to reproduce the pre-operative planned HKA was within ± 3° in 100% and 86.1% of cases, for the laboratory and clinical study respectively, which was significantly better than historical data for conventional instrumentation. X-Atlas™ was able to predict implant size to ± 1 size in 95.6% and 100%, for the femur and tibia component respectively. The X-Atlas™ imaging technology demonstrated excellent accuracy for reconstructing a 3D bone model. The results show that PSI guides created with X-Atlas™ (X-PSI™ guides) provide greater implant positioning accuracy than conventional instrumentation, without the requirement of advanced imaging. Furthermore, the X-Atlas™ imaging technology could effectively predict implant sizing, potentially reducing the number of instrument trays and improving surgical efficiency.

PMID: 33721547 [PubMed - as supplied by publisher]

Biomedizinische Technik. Biomedical engineering 2012 Apr 10

Authors: Yaffe MA, Patel A, Mc Coy BW, Luo M, Cayo M, Ghate R, Stulberg SD

Abstract
Patient-specific guides (PSG) and computer-assisted navigation (CAN) are technologies that have been developed to improve the accuracy and reproducibility of total knee arthroplasty (TKA). The purpose of this study is to compare the methodology by which a PSG system and an intraoperative navigation system (CAN) perform an anatomical registration and correctly predict femoral component size in TKA.
One hundred and eleven PSG TKA were performed, 30 of which were concurrently evaluated with CAN. PSG-predicted and CAN-predicted femoral component size were compared with the actual component selection. The process by which PSG and CAN determines component sizing was evaluated.
The PSG system was both more accurate and more precise than the CAN navigation system in predicting femoral component size in TKA.
In this study, the surgeon's final component selection was more likely to be in accordance with the PSG rather than the CAN sizing algorithm. This study suggests that intraoperative surface registration may not be as accurate as preoperative three-dimensional magnetic resonance imaging reconstructions for establishing optimal femoral component sizing.

PMID: 22868780 [PubMed - as supplied by publisher]

Clinical orthopaedics and related research 2011 Feb

Authors: Moen TC, Ghate R, Salaz N, Ghodasra J, Stulberg SD

Abstract
Aseptic osteolysis has been the single most important factor limiting the longevity of a THA. A great deal of attention has been focused on the development of implants and materials that minimize the development of osteolysis. The monoblock porous tantalum acetabular cup was designed to minimize osteolysis, but whether it does so is unclear.
We evaluated the incidence of osteolytic lesions after THA using a monoblock porous tantalum acetabular component.
We retrospectively reviewed 51 patients who had a THA using a monoblock porous tantalum acetabular cup. At a minimum of 9.6 years postoperatively (average, 10.3 years; SD, 0.2 years; range, 9.6-10.8 years), a helical CT scan of the pelvis using a metal suppression protocol was obtained. This scan was evaluated for the presence of osteolysis.
We found no evidence of osteolysis on CT scan at an average of 10.3 years.
Osteolysis appears not to be a major problem at 10 years with this monoblock porous tantalum acetabular component, but longer term followup will be required to determine whether these findings persist.
Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

PMID: 20809172 [PubMed - as supplied by publisher]

Orthopedics 2005 Sep

Authors: Gerlinger TL, Ghate RS, Paprosky WG

Abstract
Minimally invasive THA is a controversial topic in adult reconstruction. While early reports championed this new technique for faster return of function, decreased hospital stay, and less pain, these findings are being questioned. More recent reports have highlighted increased complication rates during the surgeon's learning curve and noted a lack of benefit compared with a standard incision. This article describes the senior author's technique for a minimally invasive posterior approach and emphasizes the importance of patient selection and a team approach. The size of the incision should never dictate the quality of the THA nor place the long-term results at risk. Incision length and degree of visualization are dictated by the needs of the specific surgeon as well as the patient's morphology. In appropriate patients, using a team approach and the described minimally invasive posterior approach can lead to a shortened hospital stay and rapid functional recovery without increasing the risk of complications.

PMID: 16190057 [PubMed - as supplied by publisher]