A Comparative Study Between the Stryker EZout Powered Acetabular Revision System and the Zimmer Explant Acetabular Cup Removal Systems

Abstract

The conservation of bone stock and the decrease of intraoperative acetabular fracture risk associated with revision surgery is a primary goal to improve the outcome of the procedure. The objective of this study was to evaluate and compare the performance of the Explant Acetabular Cup Removal System and the EZout Powered Acetabular Revision System in an in vitro model. Acetabular components were implanted into instrumented composite hemipelvises and divided into 2 groups, EZout System and Explant System. One experienced orthopedic surgeon and 1 orthopedic resident physician performed the removal procedures. The strains at various points in the periacetabular bone, the temperature at the implant-bone interface, the total time to removal, the torque applied to the implant and the amount of acetabular foam on each cup after extraction, as a surrogate for cavitary acetabular bone stock loss, were calculated for each test. Statistical analysis was conducted using 2-way multivariate analysis of variance followed by Tukey honestly significant difference multiple comparisons. The EZout System required an overall lower force and torque (P < 0.0001, both) during removal, producing lower strains in the surrounding composite bone. The procedure was faster (P < 0.0001) and less energy demanding with the EZout compared with the Explant. The amount of foam on the cup was on average less for the EZout than for the Explant (P < 0.05).We found that the EZout System is effective in achieving safe removal of a well-fixed acetabular component in an in vitro model of cementless fixation. This system should be considered as a reasonable alternative to manual removal techniques.

Tool-tissue forces in surgery: A systematic review

“…In regard to study demographics, all studies were primarily conducted at North American (n = 19) [ 2 , 4 , 14 , [17] , [18] , [19] , [20] , [21] , [22] , [23] , [24] , [25] , [26] , [27] , [28] , [29] , [30] , [31] , [32] , [33] ] or European (n = 26) [ 1 , 3 , 5 , [34] , [35] , [36] , [37] , [38] , [39] , [40] , [41] , [42] , [43] , [44] , [45] , [46] , [47] , [48] , [49] , [50] , [51] , [52] , [53] , [54] , [55] ] institutions ( Supplementary Information 2 ). Articles were published in medical (n = 26) [ [2] , [3] , [4] , 14 , [21] , [22] , [23] , 25 , 27 , 29 , 35 , 36 , 43 , [46] , [47] , [48] , [49] , 51 , 53 ] or engineering (n = 19) [ <...>…”

“…Articles were published in medical (n = 26) [ [2] , [3] , [4] , 14 , [21] , [22] , [23] , 25 , 27 , 29 , 35 , 36 , 43 , [46] , [47] , [48] , [49] , 51 , 53 ] or engineering (n = 19) [ 1 , 5 , [17] , [18] , [19] , [20] , 24 , 26 , 28 , [30] , [31] , [32] , [33] , [34] , [37] , [38] , [39] , [40] , [41] , [42] , 44 , 45 , 50 , 52 , 54 , 55 ] journals between 1999 and 2020 ( Supplementary Information 3 ). Evidently, this is a new and expanding field, with more articles published in the last 5 years (n = 24) [ [2] , [3] , [4] , 14 , 17 , 19 , 22 , 23 , 25 , 26 , 28 , [32] , [33] , [34] , [35] , 39 , 41 , [45] , [46] , …”

“…In terms of surgical specialty ( Supplementary Information 2 , Table 1 ), the highest proportion of studies (in-vivo and ex-vivo models) were in general surgery (n = 14, 31.1%) [ 3 , 5 , 20 , 26 , 27 , 35 , 38 , [41] , [42] , [43] , 49 , 51 , 54 ] with the majority of these involving laparoscopic procedures (n = 11) [ 3 , 5 , 26 , 34 , 38 , [41] , [42] , [43] , 49 , 54 , 55 ]; followed by neurosurgery (n = 13, 28.89%) [ 1 , 2 , 4 , 14 , 22 , 23 , 25 , 28 , 33 , 37 , 44 , 52 ], ophthalmology (n = 5, 11.11%) [ [17] , [18] , [19] , 21 , 32 ], cardiothoracic (n = 3, 6.67%) [ 26 , 30 , 53 ], vascular surgery (n = 3, 6.67%) [ 29 , 40 , 50 ], obstetrics & gynaecology (n = 2, 4.4%) [ 39 , 45 ], orthopaedics (n = 2, 4.4%) [ 47 , 48 ], otorhinolaryngology (n = 2, 4.4%) [ 36 , 46 ] and urology (n = 1, 2.2%) [ 24 ]. Ten studies (22.2%) involved robotic surgery platforms [ 1 , 14 , [17] , [18] ,…”

“…Generally, across tasks and models, specialities requiring the smallest amount of mean forces were: ophthalmology (mean of average 0.04N) [ [17] , [18] , [19] , 21 , 32 ], vascular (mean of average 0.07N) [ 29 , 40 , 50 ], neurosurgery (mean of average 0.68N) [ 1 , 2 , 4 , 14 , 22 , 23 , 25 , 28 , 33 , 37 , 44 , 52 ] and cardiothoracic surgery (mean of average 1.47N) [ 26 , 30 , 53 ]. Higher mean of average forces, in ascending order, were seen in general surgery (mean of average 4.67N) [ 3 , 5 , 20 , 26 , 27 , 35 , 38 , [41] , [42] , [43] , 49 , 51 , 54 ], otorhinolaryngology (mean of average 8.49N) [ 36 , 46 ], obstetrics and gynaecology (mean of average 8.69N) [ 39 , 45 ], urology (mean of average 9.79N) [ 24 ] and orthopaedic surgery (mean of average 210N) [ 47 , 48 ].

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“…Across specialities and manoeuvres, nervous tissue (principally the brain & retina) required the least amount of force to manipulate (mean of average 0.4N, mean max 1.74N, n = 17) [ 1 , 2 , 4 , [17] , [19] , [21] , [22] , [23] , 25 , 28 , 32 , 33 , 37 , 44 , 52 ] with retinal forces always below 0.01N ( Table 1 ) [ [17] , [18] , [19] , 21 , 32 ]. Mean forces applied on epithelial tissues were higher (mean of average 3.8N, mean max 9.7N, n = 18) [ 3 , 14 , 20 , 24 , 26 , 27 , 29 , 35 , 38 , [40] , [41] , [42] , [43] , 45 , 50 , 51 , 54 ], followed by muscle (mean of average 4.1N, mean max 6.7N, n = 3) [ 5 , 49 , 51 ], and connective tissue including bone (mean of average 45.8N, mean max 347.9N, n = 10) [ 20 , 26 , 30 , 31 , 36 , 39 , [46] , [47] , [48] , 53 ]. Mean forces per surgical manoeuvre are reported in Table 1 with drilling recording the highest forces (mean of average 14.1N, mean max 25.9N, n = 2) [ 46 , 48 ], whilst sharp dissection recorded the lowest (mean of average 0.03N, mean max not available, n = 1) [ 1 ].…”