Human Dermal Allograft Superior Capsule Reconstruction with Graft Length determined at Glenohumeral Abduction Angles of 20 and 40 degrees Decreases Joint Translation and Subacromial Pressure without Compromising Range of Motion: A Cadaveric Biomechanical Study

2021 ◽  
Author(s):  
James E. Tibone ◽  
Colin Mansfield ◽  
Adam Kantor ◽  
James Giordano ◽  
Charles Lin ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Biomechanical Study ◽  
Superior Capsule Reconstruction ◽  
Graft Length

scholarly journals Mapping of the Inferior Glenohumeral Ligament for Suture Pullout Strength: A Biomechanical Analysis

2021 ◽  
Vol 9 (1) ◽  
pp. 232596712096964
Author(s):  
Sumit Raniga ◽  
Joseph Cadman ◽  
Danè Dabirrahmani ◽  
David Bui ◽  
Richard Appleyard ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Biomechanical Study ◽  
Labral Repair ◽  
Pullout Strength ◽  
Recurrent Instability ◽  
Glenohumeral Ligament ◽  
Time Zero ◽  
Capsular Plication ◽  
Inferior Glenohumeral Ligament ◽  
The Impact

Background: Suture pullout during rehabilitation may result in loss of tension in the inferior glenohumeral ligament (IGHL) and contribute to recurrent instability after capsular plication, performed with or without labral repair. To date, the suture pullout strength in the IGHL is not well-documented. This may contribute to recurrent instability. Purpose/Hypothesis: A cadaveric biomechanical study was designed to investigate the suture pullout strength of sutures in the IGHL. We hypothesized that there would be no significant variability of suture pullout strength between specimens and zones. Additionally, we sought to determine the impact of early mobilization on sutures in the IGHL at time zero. We hypothesized that capsular plication sutures would fail under low load. Study Design: Descriptive laboratory study. Methods: Seven fresh-frozen cadaveric shoulders were dissected to isolate the IGHL complex, which was then divided into 18 zones. Sutures in these zones were attached to a linear actuator, and the resistance to suture pullout was recorded. A suture pullout strength map of the IGHL was constructed. These loads were used to calculate the load applied at the hand that would initiate suture pullout in the IGHL. Results: Mean suture pullout strength for all specimens was 61.6 ± 26.1 N. The maximum load found to cause suture pullout through tissue was found to be low, regardless of zone of the IGHL. Calculations suggest that an external rotation force applied to the hand of only 9.6 N may be sufficient to tear capsular sutures at time zero. Conclusion: This study did not provide clear evidence of desirable locations for fixation in the IGHL. However, given the low magnitude of failure loads, the results suggest the timetable for initiation of range-of-motion exercises should be reconsidered to prevent suture pullout through the IGHL. Clinical Relevance: From this biomechanical study, the magnitude of force required to cause suture pullout through the IGHL is met or surpassed by normal postoperative early range-of-motion protocols.

scholarly journals The effect of humeral polyethylene insert constraint on reverse shoulder arthroplasty biomechanics

2017 ◽  
Vol 10 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Irfan Abdulla ◽  
Daniel G Langohr ◽  
Joshua W. Giles ◽  
James A. Johnson ◽  
George S. Athwal
Keyword(s):  
Range Of Motion ◽  
Shoulder Arthroplasty ◽  
Reverse Shoulder Arthroplasty ◽  
Biomechanical Study ◽  
Polyethylene Insert ◽  
Muscle Forces ◽  
Joint Load ◽  
Joint Loads ◽  
Load Angle ◽  
Active Abduction

Background There is little information on the effects of altering reverse shoulder arthroplasty (RSA) polyethylene constraint on joint load, load angle and deltoid force. The present biomechanical study aimed to investigate the effects of changing RSA polyethylene constraint on joint load, load angle, deltoid force and range of motion. Methods A custom RSA implant capable of measuring forces across the joint with varying polyethylene constraint was tested in six cadaveric shoulders. Standard-, low- and high-constraint (retentive) polyethylene liners were tested, and joint kinematics, loads and muscle forces were recorded. Results When polyethylene constraint was altered, joint load and load angle during active abduction were not affected significantly ( p > 0.19). Additionally, the force required by the deltoid for active abduction was not affected significantly by cup constraint ( p = 0.144). Interestingly, active abduction range of motion was also not affected significantly by changes in cup constraint ( p > 0.45). Conclusions Altering polyethylene cup constraint in RSA to enhance stability does not significantly alter resultant joint loads and deltoid forces. Surprisingly, terminal abduction range of motion was also not significantly different with varying cup constraint, indicating that terminal impingement may be tuberosity related rather than polyethylene.

Unilateral cervical facet dislocation: a biomechanical study of several constructs including unilateral lateral mass fixation supplemented by an interspinous cable

2012 ◽  
Vol 16 (3) ◽  
pp. 251-256 ◽  
Author(s):  
Ron I. Riesenburger ◽  
Tejaswy Potluri ◽  
Nikhil Kulkarni ◽  
William Lavelle ◽  
Marie Roguski ◽  
...  
Keyword(s):  
Range Of Motion ◽  
Gold Standard ◽  
Biomechanical Study ◽  
Anterior Cervical Discectomy ◽  
Lateral Mass ◽  
Intact Specimen ◽  
Cervical Discectomy ◽  
Lateral Mass Screws ◽  
The Right ◽  
Cervical Facet

Object Both ventral and dorsal operative approaches have been used to treat unilateral cervical facet injuries. The gold standard ventral approach is anterior cervical discectomy and fusion. There is, however, no clear gold standard dorsal operation. In this study, the authors tested the stability of multiple posterior constructs, including unilateral lateral mass fixation supplemented by an interspinous cable. Methods Six fresh human cervical spine specimens (C3–T1) were tested by applying pure moments to the C-3 vertebral body in increments of 0.5 Nm from 0 Nm to 2.0 Nm. Each specimen was tested in the following 8 conditions (in the order shown): 1) intact; 2) after destabilization via injury to the C5–6 facet; 3) with bilateral C5–6 lateral mass screws and rods; 4) after further destabilization by creating a right unilateral lateral mass fracture of C-5 (which rendered secure screw placement into the right C-5 lateral mass impossible); 5) with unilateral left C5–6 lateral mass screws and rod; 6) with unilateral C5–6 lateral mass screws and rod supplemented with an interspinous cable; 7) with a bilateral multilevel dorsal construct C4–6; and 8) after a C5–6 anterior cervical discectomy and fusion (ACDF) procedure with a polyetheretherketone graft and plate. Results The bilateral C5–6 lateral mass construct reduced the range of C5–6 motion to 33.6% of normal. The unilateral C5–6 lateral mass construct resulted in an increased range of motion to 110.1% of normal. The unilateral lateral mass construct supplemented by an interspinous cable reduced the C5–6 range of motion to 89.4% of normal. The bilateral C4–6 lateral mass construct reduced the C5–6 range of motion to 44.2% of normal. The C5–6 ACDF construct reduced the C5–6 range of motion to 62.6% of normal. Conclusions The unilateral lateral mass construct supplemented by an interspinous cable does reduce range of motion compared with an intact specimen, but is significantly inferior to a C4–6 bilateral lateral mass construct. When using a dorsal approach, the unilateral construct with a cable should only be considered in selected instances.

A biomechanical investigation of the static stabilisers of the glenohumeral joint in the dog

2005 ◽  
Vol 18 (02) ◽  
pp. 55-61 ◽  
Author(s):  
N. E. Lambrechts ◽  
N. G. J. Maritz ◽  
K. E. Joubert ◽  
M. J. Gray
Keyword(s):  
Range Of Motion ◽  
Glenohumeral Joint ◽  
Static Stability ◽  
Biomechanical Study ◽  
Lateral Direction ◽  
Relative Contribution ◽  
Glenohumeral Ligaments ◽  
Wide Range ◽  
Significant Difference ◽  
Biomechanical Features

SummaryThe aim was to determine the relative contribution of the glenohumeral ligaments/joint capsule complex and the limited joint volume/adhesion-cohesion (LJV/AC) mechanisms to the static stability of the canine glenohumeral joint (GHJ). The GHJ of 32 complete cadaver specimens were manipulated to determine the presence of gross laxity (>2mm translation) at joint angles of 150°, 135° and 90°. Following the removal of the peri-articular muscles, laxity was measured by applying a 15N force to the scapula in a variety of directions whilst the humerus was fixed to a jig. This was repeated for the abovementioned angles in intact joints and after venting and flushing to eliminate the LJV/AC mechanisms. Results of clinical palpation and biomechanical studies were compared. Manipulation revealed a marked variation between joints although there was a tendency for progressive laxity as the joint was flexed. This finding was supported by the biomechanical study that also demonstrated no significant difference between intact and vented joints except in a cranio-caudal direction at 135° and 90°, and in a medial/lateral direction at 135°. Static stabilisers permitted a wide range of motion. Individual clinical palpations did not correlate well with biomechanical findings. Manipulation was difficult to perform and is unlikely to be a reliable method for determining subtle joint laxity. The static stabilisers do not appear to play a significant role in providing joint constraint during normal range of motion (except extension). Diagnoses of pathological laxity attributable to the static stabilisers should be made with caution and surgical treatments should take cognizance of the above-mentioned biomechanical features.

scholarly journals An In Vitro Biomechanical Evaluation of a Lateral Lumbar Interbody Fusion Device With Integrated Lateral Modular Plate Fixation

2020 ◽  
pp. 219256822090561
Author(s):  
Ryan DenHaese ◽  
Anup Gandhi ◽  
Chris Ferry ◽  
Sam Farmer ◽  
Randall Porter
Keyword(s):  
Range Of Motion ◽  
Pedicle Screw ◽  
Screw Fixation ◽  
Plate Fixation ◽  
Axial Rotation ◽  
Pedicle Screw Fixation ◽  
Biomechanical Study ◽  
Flexion Extension ◽  
Bilateral Pedicle Screw

Study Design: In vitro cadaveric biomechanical study. Objective: Biomechanically characterize a novel lateral lumbar interbody fusion (LLIF) implant possessing integrated lateral modular plate fixation (MPF). Methods: A human lumbar cadaveric (n = 7, L1-L4) biomechanical study of segmental range-of-motion stiffness was performed. A ±7.5 Nċm moment was applied in flexion/extension, lateral bending, and axial rotation using a 6 degree-of-freedom kinematics system. Specimens were tested first in an intact state and then following iterative instrumentation (L2/3): (1) LLIF cage only, (2) LLIF + 2-screw MPF, (3) LLIF + 4-screw MPF, (4) LLIF + 4-screw MPF + interspinous process fixation, and (5) LLIF + bilateral pedicle screw fixation. Comparative analysis of range-of-motion outcomes was performed between iterations. Results: Key biomechanical findings: (1) Flexion/extension range-of-motion reduction with LLIF + 4-screw MPF was significantly greater than LLIF + 2-screw MPF ( P < .01). (2) LLIF with 2-screw and 4-screw MPF were comparable to LLIF with bilateral pedicle screw fixation in lateral bending and axial rotation range-of-motion reduction ( P = 1.0). (3) LLIF + 4-screw MPF and supplemental interspinous process fixation range-of-motion reduction was comparable to LLIF + bilateral pedicle screw fixation in all directions ( P ≥ .6). Conclusions: LLIF with 4-screw MPF may provide inherent advantages over traditional 2-screw plating modalities. Furthermore, when coupled with interspinous process fixation, LLIF with MPF is a stable circumferential construct that provides biomechanical utility in all principal motions.

scholarly journals The impact of different artificial disc heights during total cervical disc replacement: an in vitro biomechanical study

2021 ◽  
Vol 16 (1) ◽  
Author(s):  
Xiao-Fei Wang ◽  
Yang Meng ◽  
Hao Liu ◽  
Bei-Yu Wang ◽  
Ying Hong
Keyword(s):  
Range Of Motion ◽  
Facet Joint ◽  
Biomechanical Study ◽  
Disc Height ◽  
Cervical Disc ◽  
Artificial Disc ◽  
Lateral Bending ◽  
Cervical Disc Replacement ◽  
Flexion Extension

Abstract Background The principles of choosing an appropriate implant height remain controversial in total cervical disc replacement (TDR). By performing an in vitro biomechanical study and exploring the biomechanical impact of implant height on facet joint and motion function, the study aimed to offer valid proposals regarding implant height selection during TDR. Methods A total of 6 fresh-frozen male cadaveric cervical spines (C2–C7) with 5 mm intervertebral disc height at C5/6 level were enrolled in the study. Specimens with the intact condition and with different height artificial discs were tested. Facet joint pressures and range of motion under each condition were recorded using a specialized machine. Results The artificial disc heights that were involved in this study were 5 mm, 6 mm, and 7 mm. The range of motion decreased along with the increment of implant height, while facet joint pressure showed an opposite trend. Specimens with a 5 mm implant height could provide a similar range of motion (11.8° vs. 12.2° in flexion-extension, 8.7° vs. 9.0° in rotation, 7.9° vs. 8.2° in lateral bending) and facet joint pressure (27.8 psi vs. 25.2 psi in flexion, 59.7 psi vs. 58.9 psi in extension, 24.0 psi vs. 22.7 psi in rotation, 32.0 psi vs. 28.8 psi in lateral bending) compared with intact specimens. Facet joint pressure of specimens with 6 mm implant height (≥ 1 mm in height) increased during flexion at the C5–6 segment (30.4 psi vs. 25.2 psi, P = 0.076). However, specimens with 7 mm implant height (≥ 2 mm in height) showed a significant reduction in motion (9.5° vs. 12.2° in flexion-extension, P < 0.001) and increment of facet joint pressure at C5–6 segment (44.6 psi vs. 25.2 psi in flexion, 90.3 psi vs. 58.9 psi in extension, P < 0.0001) and adjacent segments. Conclusions This study suggested that an appropriate artificial disc height can achieve near-normal biomechanical properties and is recommended. We should be very cautious when using artificial discs ≥ 1 mm in height compared to normal. However, implants ≥ 2 mm in height compared to normal significantly increased the facet joint pressure and decreased the range of motion; therefore, it should not be used in clinical practice.

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