Total Knee Arthroplasty With a Computer-navigated Saw: A Pilot Study

Abstract

Background Computer-aided surgery aims to improve implant alignment in TKA but has only been adopted by a minority for routine use. A novel approach, navigated freehand bone cutting (NFC), is intended to achieve wider acceptance by eliminating the need for cumbersome, implant-specific mechanical jigs and avoiding the expense of navigation. Questions/Purposes We determined cutting time, surface quality, implant fit, and implant alignment after NFC of synthetic femoral specimens and the feasibility and alignment of a complete TKA performed with NFC technology in cadaveric specimens. Methods Seven surgeons prepared six synthetic femoral specimens each, using our custom NFC system. Cutting times, quality of bone cuts, and implant fit and alignment were assessed quantitatively by CT surface scanning and computational measurements. Additionally, a single surgeon performed a complete TKA on two cadaveric specimens using the NFC system, with cutting time and implant alignment analyzed through plain radiographs and CT. Results For the synthetic specimens, femoral coronal alignment was within ± 2°of neutral in 94% of the specimens. Sagittal alignment was within 0°to 5°of flexion in all specimens. Rotation was within ± 1°of the epicondylar axis in 97% of the specimens. The mean time to make cuts improved from 13 minutes for the first The institution of four authors (KLG, AB, CWH, HH) has received, during the study period, funding from DePuy Orthopaedics Inc (Warsaw, IN, USA) and contract research funding from Arthrex Inc (Naples, FL, USA), Biomet Inc (Warsaw, IN, USA), Naval Health Research Center (San Diego, CA, USA), Empirical Testing Corp (Colorado Springs, CO, USA), Exactech Inc (Gainesville, FL, USA), Exponent Inc (Philadelphia, PA, USA), ESKA (Lübeck, Germany), Gruppo Bioimpianti (Milan, Italy), Kyocera Medical Corp (Osaka, Japan), Implanet (Martillac, France), Ortho Development (Draper, UT, USA), Otis Glebe Medical Research Foundation (Omaha, NE, USA), Renovis Surgical Technologies (Redlands, CA, USA), Smith & Nephew Inc (Memphis, TN, USA), SoftJoint (Iowa City, IA, USA), Stryker Orthopaedics (Mahwah, NJ, USA), Spine Medica (Atlanta, GA, USA), and Tornier (Montbonnot, France). The institution of one of the authors (CRM) has received, during the study period, funding from Smith & Nephew. One of the authors (KLG) certifies that he, or a member of his immediate family, has received or may receive payments or benefits, during the study period, an amount of $100,001 to $1,000,000 from Biomet Inc. One of the authors (HH) certifies that he, or a member of his immediate family, has received or may receive payments or benefits, during the study period, an amount of $10,000 to $100,000 from AMTI (Watertown, MA, USA), an amount of less than $10,000 from Arthrex, an amount of $10,000 to $100,000 from Biomet Inc, an amount of less than $10,000 from Orthopedic Surgical Manufacturers Association (Rockville, MD, USA), an amount of less than $10,000 from SoftJoint, and an amount of less than $10,000 from SI-BONE (San Jose, C...

Accuracy assessment of a novel image-free handheld robot for Total Knee Arthroplasty in a cadaveric study

“…Garvin et. al presented results from a navigated TKA saw blade [25]. They reported implant alignment varus/valgus errors of −0.55±1.1° and slope errors of 1.6±1.4°.…”

Alignment of the tibial component in total knee arthroplasty procedures using an intramedullary or extramedullary guide: double-blind randomized prospective study

“… 1 , 10 There are certain difficulties in undertaking general introduction of navigation systems, such as the cost, the increased duration of surgery and the need for specific software for each implant. 11 There is also the possibility of complications, such as fractures at the fixation points for the femoral and tibial guides, because of the pins that firmly hold the position sensors for the navigation. Nonetheless, we believe that technological tools that improve the general results and make them less divergent should be studied and possibly used, so that the final results from TKA might become more predictable.…”

“…Although most authors have considered that seeking adequate alignment is a crucial element in the success of TKA procedures, 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 11 , 13 other factors may be as determinant as the alignment, or more so, for the long-term results. Parratte et al 9 followed up 398 knees that underwent TKA, over a 15-year period and analyzed the long-term results.…”

Surgical Accuracy of an Early Intervention Knee Implant Instrumentation System

“…In one study, a group of surgeons performed the bone cuts for a total knee component on sawbones distal femurs, using "freehand navigation" where the saw blade was guided visually on a computer screen. 11 Measurements were made of the accuracy of the alignment and component fit, in a similar way to our study. Some errors were encountered due to the flexibility of the saw blade, consistent with studies where the blade path was closely controlled and accuracy was improved.…”