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

Abstract

Background Patient-specific instrumentation (PSI) systems for total shoulder arthroplasty (TSA) can improve glenoid component placement, but may involve considerable expense and production delays. The purpose of this study was to evaluate a novel technique for in-house production of 3-dimensionally printed, patient-specific glenoid guides. We hypothesized that our PSI guide would improve the accuracy of glenoid guide pin placement compared with a standard TSA guide. Methods We randomized 20 cadaveric shoulders to receive pin placement via the PSI guide (n = 10, study group) or standard TSA guide (n = 10, control group). PSI guides were designed to fit each glenoid based on 3-dimensional scapular models constructed from computed tomography scans. A presurgical plan was created for the guide pin trajectory in neutral version and inclination based on individual scapular anatomy. After pin placement, 3-dimensional models from repeated computed tomography scans were superimposed to calculate deviation from the presurgical plan for each specimen. Results Inclination deviation was significantly lower in the PSI group than in the standard guide group (1.5° ± 1.6° vs. 6.4° ± 5.0°, P = .009). The glenoid entry site exhibited significantly less deviation in the PSI group (0.8 ± 0.6 mm vs. 2.1 ± 1.2 mm, P = .008). The average production cost and time for the PSI guides were $29.95 and 4 hours 40 minutes per guide, respectively. Conclusions The PSI guide significantly improved the accuracy of glenoid pin placement compared with the standard TSA guide. Our PSI guides can be produced in-house, inexpensively, and with substantially reduced time compared with commercially available guides.

Glenoid Inclination: Choosing the Transverse Axis Is Critical—A 3D Automated versus Manually Measured Study

“…Another issue is that the trigonum positioning and the overall morphology of the global medial side of the scapular blade is highly variable and leads to more difficulties in identifying this medial landmark. Moreover, in the literature, authors give different definitions of the trigonum that can be the most medial point of the scapula [ 33 , 34 ] or the intersection between the spine and the medial border of the scapula [ 22 , 26 , 35 , 36 ] (the definition we have chosen in our article). It can also be termed “trigonum scapulae” [ 34 , 37 , 38 ], “trigonum spinae” [ 39 ] or “os trigonum” [ 40 ] with no further precision.…”

Implications of navigation system use for glenoid component placement in reverse shoulder arthroplasty

“…The meta-analysis of Cabarcas et al also reported no significant differences in accuracy between PSI and standard instrumentation 24 . Furthermore, PSIs take time and cost to make after planning and are not used in all patients 25 .…”

Uso de planificación preoperatoria e impresión 3D en ortopedia y traumatología: ingresando en una nueva era

“…26 3. Incremento de la precisión quirúrgica: Cabarcas y colaboradores 27 demostraron en un estudio cadavérico aleatorizado que el uso de instrumental específico en artroplastías de hombro incrementó la precisión en la inserción del pin glenoideo en comparación con las guías estándar. En otro estudio, 46 pacientes con artrosis glenohumeral avanzada fueron asignados aleatoriamente a plantillas preoperatorias de tomografía computarizada tridimensional con instrumentación estándar o con instrumentación específica y se compararon con un grupo de 17 pacientes con imágenes bidimensionales e instrumentación estándar utilizados como control.…”