Reverse Shoulder Arthroplasty With Patient-specific Glenoid Implant Positioning Guides

Abstract

Reverse shoulder arthroplasty is the treatment of choice for rotator cuff tear arthroplasty. The success of the procedure depends largely on proper positioning and stable fixation of the glenoid component. Achieving the ideal position of the implant always remains a challenge to the operating surgeon. Various methods have been suggested to improve the initial fixation of the glenosphere intraoperatively. Even though computer navigation has shown encouraging results, it is associated with inherent difficulties and involves a significant learning curve. These difficulties may be overcome by the use of patient-specific instrumentation. The clinical utility and accuracy of patient-specific instrumentation has been studied in the setting of total shoulder arthroplasty. This article describes the use of patient-specific glenoid implant positioning guides in reverse shoulder arthroplasty. After a cadaveric pilot study, reverse shoulder arthroplasty was performed in 7 patients using the patient-specific guides. The patient-specific glenoid implant positioning system provides for preoperative planning on a virtual 3D model of the scapula derived from CT scan images. The accuracy of the patient-specific guides was determined by comparing the postoperative version and inclination of the implant with the preoperatively planned values. The mean native version of the glenoid was 5.2 degrees of retroversion (range, + 0.8 to À 14.38 degrees; SD = 5.3) and mean native inclination was 12.25 degrees of superior tilt (range, 8.07 to 18.24 degrees; SD = 4.04). The mean version of the glenoid component as chosen in the preoperative planning was 0.42 degrees (range, À 1 to 3 degrees; SD = 1.27). The mean inclination chosen was 9.19 degrees (range, À 8 to 10 degrees of inferior tilt; SD = 0.91). Postoperatively, we achieved a mean version of 0.38 degrees (range, À2.85 to 2.0 degrees. SD = 1.98) (negative values denote retroversion and vice versa). Postoperative mean inclination was À 9.15 degrees (range, À 7.5 to À 11.1 degrees; SD = 1.175) (negative values denote inferior tilt). The accuracy of reproducing the planned version was 0.04 ± 0.71 degrees with a maximum error of 2.05 degrees and a minimum error of 0.4 degrees. The accuracy of reproducing the planned inclination was 0.04 ± 0.26 degrees, with a maximum error of 2.5 degrees and a minimum error of 0.3 degrees Thus the patient-specific guides seems to be effective in achieving accurate placement of the glenoid component in reverse shoulder arthroplasty. It may help to overcome the problems native to computer navigation. However, more number of studies with longer duration of follow-up is necessary to prove the long-term benefits.This newly developed patient-specific planning and guiding system allows preoperative determination of the glenoid implant position on a virtual 3D model of the scapula reconstructed from preoperative CT images. The system consists of a software component, SurgiCase Connect, and a hardware component, the Match Point System. FIGURE 4. A and B, The patient-...

Accuracy of patient-specific instrumentation in shoulder arthroplasty: a systematic review and meta-analysis

“…The only other article to document the necessary time for production of the patient-specific device reported a minimum of 5 weeks 40 Table IIIPSI devices and technology used among included articlesPSI manufacturerArticle(s) citedDescriptionPSITornier–Wright MedicalGauci et al, 16 2016Walch et al, 43 2015Berhouet et al, 3 2018Four-pin peripheral supportSurgeon introduces onto glenoid.2.5-mm titanium guide wire passed through central hole.Polyamide; EOSINT P380 selective laser sintering (EOS, Krailling, Germany).Walch et al, 2015∗Materialise (Patient-Specific Shoulder Guide)Dallalana et al, 7 2016Levy et al, 27 2014Subramanya and Herald, 36 2014Heylen et al, 20 2016Removal of soft tissues from anterosuperior glenoid rim and exposure of coracoid base necessary.Guide fitted to stable position on native glenoid.Central guide pin drilled into native glenoid.Polyamide material. Selective laser sintering.Heylen et al, 2016†Zimmer Biomet (Signature Glenoid Shoulder System)Throckmorton et al, 38 2015Pietrzak, 32 2013Lau and Keith, 26 2018Throckmorton et al, 39 2014TSA: pin trajectory is neutral version and inclination.rTSA: pin trajectory is 10° of inferior tilt and neutral version.Guide applied to anterior glenoidMaterial not reported.Lau and Keith, 2018‡Custom Orthopaedic Solutions (Glenoid Intelligent Reusable Instrument System)Iannotti et al, 25 2015Iannotti et al, 23 2014Iannotti et al, 24 2017Reusable—cannulated handle over guide pin.3 or 4 adjustable peripheral legs fit on glenoid.Each leg specified leg length (1-mm increments).Legs locked by tightening collets after desired length achieved with SmartBone model (Custom Orthopaedic Solutions, Cleveland, Ohio, USA).Duocentric Group, Aston Medical (Personal Fit)Trouilloud et al, 40 2014Guide pin is passed through guide at chosen center of glenoid.Humeral component fits onto humeral head and cutting guide placed against it.Trouilloud et al, 2014§Astro Manufacturing & Design, Eastlake, OH, USA (patient-specific stereolithography devices)Hendel et al, 19 20122 instrument parts.First instrument fits on anterior glenoid.Drill guide places glenoid pin and superior guide pin; superior pin placed into base of coracoid.After glenoid...…”

Use of Patient-Specific Instrumentation (PSI) for glenoid component positioning in shoulder arthroplasty. A systematic review and meta-analysis

“…The reported outcomes were deviation from the planning for version and inclination in all studies, from the entry point in 10 studies (five cadaveric and five clinical studies) [ 27 – 30 , 33 – 38 ] and from the rotation in three studies (one cadaveric and two clinical studies) [ 28 , 33 , 34 ]. Seven studies also reported the number of outliers (three cadaveric and four clinical studies) [ 28 , 29 , 31 , 32 , 36 – 38 ]. Reaming depth has never been reported.…”

Novel 3-dimensionally printed patient-specific guide improves accuracy compared with standard total shoulder arthroplasty guide: a cadaveric study

“…In general, available evidence indicates that patient-specific devices improve the implantation accuracy of either the central glenoid guide pin or glenoid prosthesis based on some form of predetermined surgical plan 9, 13, 15, 20, 30. However, most published articles used patient-specific devices that were outsourced to an external manufacturer 2, 6, 8, 13, 14, 15, 22, 23, 27, 28, 30, 31, 34. Outsourcing production of patient-specific devices to external manufacturers may involve considerable expenses that could potentially exclude all but the highest-volume, highest-earning practices from benefiting from this technology.…”

“…Our power analysis determined that a sample size of 20 specimens was necessary for the purposes of this investigation, which is greater than that in the majority of available cadaveric or clinical studies investigating the impact of PSI devices on TSA 2, 9, 22, 23, 24, 27, 28, 29, 32, 34. Although it is impossible to represent the entire spectrum of TSA patients with this sample, the addition of a standard instrumentation control adds further validity that was absent in several previous investigations 2, 13, 23, 27, 32, 34.…”