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Acromion

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Andreas B. Imhoff – One of the best experts on this subject based on the ideXlab platform.

  • risk of fracture of the Acromion depends on size and orientation of acromial bone tunnels when performing acromioclavicular reconstruction
    Knee Surgery Sports Traumatology Arthroscopy, 2018
    Co-Authors: Felix Dyrna, Celso Cruz Timm De Oliveira, Michael D Nowak, Andreas Voss, Elifho Obopilwe, Sepp Braun, Leo Pauzenberger, Andreas B. Imhoff

    Abstract:

    Current techniques for anatomic repair of the dislocated acromioclavicular (AC) joint aim on reconstruction of the AC ligaments and utilize tunnels drilled through the Acromion
    . This improves the stability of the reconstruction but might also increase the risk of fractures at the Acromion. The purpose of this study was to evaluate the fracture risk for the Acromion after transacromial tunnel placement for anatomic AC joint stabilization procedure. It was hypothesized that the risk of fracture of the Acromion is correlated to size and orientation of bone tunnels commonly used for anatomic AC joint reconstruction. A finite element analysis was used to simulate multiple bone tunnels and incoming force vectors (lateral vs. superior). Different tunnels were analysed, horizontal meaning an anterior–posterior orientation versus a vertical inferior–superior orientation through the Acromion. Two tunnel diameters were simulated (2.4 vs. 4.5 mm). Furthermore, the tunnel length and distance between tunnels were altered. Forty-five cadaveric specimens (median age: 64 years, range 33–71 years) were utilized for data acquisition. Out of these, 30 specimens were used to evaluate basic tunnel orientations and drill diameters using a MTS 858 servohydraulic test system. With regard to the tunnel orientation and drill hole size, the loads to failure were limited. The Acromion is at higher fracture risk, with a superior to inferior directed incoming force. Position, size and direction of bone tunnels influenced the loads to failure. Horizontal tunnels with a higher diameter (4.5 mm) had the most impact on load to failure reduction. A long horizontal tunnel with a diameter of 4.5 mm reduced the load to failure with medial direction of force to 25% of the native Acromion. The identical tunnel with a diameter of 2.4 mm reduced the load to failure to 61%. Both 2.4-mm horizontal tunnels with a medium and short length did not reduce the load to failure. Tunnels placed at the Acromion did not result in an increased risk of fracture. However, descriptive data showed a tendency for an increased fracture risk if tunnels are placed at the Acromion, especially in horizontal direction with diameters of 4.5 mm. In addition, the pattern of fracture was dependent on the orientation of the bone tunnels and the size. However, the results indicate a “safe zone” for the placement of bone tunnels within the anterior half of the Acromion, which does not affect the loads to failure at the Acromion. Therefore, current techniques for anatomic AC joint reconstruction which utilize fixation of grafts or sutures at the Acromion are safe within current ranges of tunnel placement and sizes.

  • Acromion morphology and bone mineral density distribution suggest favorable fixation points for anatomic acromioclavicular reconstruction
    Knee Surgery Sports Traumatology Arthroscopy, 2017
    Co-Authors: Andreas B. Imhoff, Felix Dyrna, Andreas Voss, Elifho Obopilwe, Andrea Achtnich, Alex Hoberman, Augustus D Mazzocca, Knut Beitzel

    Abstract:

    Purpose
    Recent techniques for acromioclavicular (AC) joint reconstruction focus on additional AC cerclage to coracoclavicular (CC)-reconstructions. Due to the specific slim bone morphology at the Acromion, there are concerns regarding these additional bone tunnels, as they may predispose to fracture and break out. The purpose of this study was to investigate anatomic properties of the Acromion which may help improve surgical techniques directed at injuries to the AC joint. It was hypothesized that via measurements of thickness and density points of increased strength and support could be identified on the Acromion.

  • Acromion reconstruction after total arthroscopic Acromionectomy: Salvage procedure using a bone graft.
    Arthroscopy, 2001
    Co-Authors: Jens D. Agneskirchner, Helmut H. Fredrich, Andreas B. Imhoff

    Abstract:

    We report 2 cases of Acromion reconstruction with a bone graft as a salvage procedure after total arthroscopic Acromionectomy. Complete removal of the Acromion had produced severe shoulder abnormality with pain and joint stiffness. We present the operative technique of Acromion reconstruction using a corticocancellous bone graft from the iliac crest. Recreation of the Acromion as a fulcrum of the shoulder joint as well as an important physiological insertion area for the deltoid muscle markedly improved pain and range of motion in these patients. In conclusion, based on these cases, we believe that total Acromionectomy is an inadequate procedure for treatment of shoulder impingement syndrome. Acromion reconstruction with a bone graft is an alternative that may lead to improvement of clinical symptoms.

Charles S Neer – One of the best experts on this subject based on the ideXlab platform.

  • anterior acromioplasty for the chronic impingement syndrome in the shoulder
    Journal of Bone and Joint Surgery American Volume, 2005
    Co-Authors: Charles S Neer

    Abstract:

    Impingement on the tendinous portion of the rotator cuff by the coraco-acromial ligament and the anterior third of the Acromion is responsible for a characteristic syndrome of disability of the shoulder. A characteristic proliferative spur and ridge has been noted on the anterior lip and undersurface of the anterior process of the Acromion and this area may also show erosion and eburnation. The treatment of the impingement is to remove the anterior edge and undersurface of the anterior part of the Acromion with the attached coraco-acromial ligament. The impingement may also involve the tendon of the long head of the biceps and if it does, it is best to decompress the tendon and remove any osteophytes which may be in its groove, but to avoid transplanting the biceps tendon if possible. Hypertrophic lipping at the acromio-clavicular joint may impinge on the supraspinatus tendon when the arm is in abduction and, if the lip is prominent, this joint should be resected. These are the principles of anterior acromioplasty.

    Fifty shoulders in forty-six patients have been subjected to anterior acromioplasty during the past five years. Nineteen had proliferative bursitis and tendinitis or partial tears of the supraspinatus, without roentgenographic evidence of calcium deposits, and twenty had complete tears of the supraspinatus and the results in these thirty-nine patients from one to five years following surgery were good. Eleven patients with residual impingement following partial lateral Acromionectomy were improved but their results were impaired by pre-existent deltoid weakness and scar. Anterior acromioplasty may offer better relief of chronic pain in carefully selected patients with mechanical impingement, while it provides better exposure for repairing tears of the supraspinatus, and may prevent further impingement and wear at the critical area without loss of deltoid power.

  • anterior acromioplasty for the chronic impingement syndrome in the shoulder
    Journal of Bone and Joint Surgery American Volume, 2005
    Co-Authors: Charles S Neer

    Abstract:

    Impingement on the tendinous portion of the rotator cuff by the coracoacromial ligament and the anterior third of the Acromion is responsible for a characteristic syndrome of disability of the shoulder. A characteristic proliferative spur and ridge has been noted on the anterior lip and undersurface of the anterior process of the Acromion and this area may also show erosion and eburnation. The treatment of the impingement is to remove the anterior edge and undersurface of the anterior part of the Acromion with the attached coracoacromial ligament. The impingement may also involve the tendon of the long head of the biceps and if it does, it is best to decompress the tendon and remove any osteophytes which may be in its groove, but to avoid transplanting the biceps tendon if possible. Hypertrophic lipping at the acromio-clavicular joint may impinge on the supraspinatus tendon when the arm is in abduction and, if the lip is prominent, this joint should be resected. These are the principles of anterior acromioplasty.

Lawrence V Gulotta – One of the best experts on this subject based on the ideXlab platform.

  • influence of implant design and parasagittal acromial morphology on acromial and scapular spine strain after reverse total shoulder arthroplasty a cadaveric and computer based biomechanical analysis
    Journal of Shoulder and Elbow Surgery, 2020
    Co-Authors: Sarav S Shah, Joseph M Gentile, Xiang Chen, Andreas Kontaxis, David M Dines, Russell F Warren, Samuel A Taylor, Amirhossein Jahandar, Lawrence V Gulotta

    Abstract:

    Background The purpose was to analyze the influence of deltoid lengthening due to different implant designs and anatomical variations of the Acromion and scapular spine in the parasagittal plane on strain patterns after reverse shoulder arthroplasty (RSA). Methods Ten cadaveric shoulders with strain rosettes placed on the surface of acromial body (Levy II) and scapular spine (SS) (Levy III) were tested using a shoulder simulator. RSA using humeral onlay (+3,+5,+8,+10,+13mm) and glenosphere lateralization (0,+6mm) was performed. Arm lengthening and magnitude of strain on Acromion/SS was measured. Length of deltoid was assessed using validated computer modeling. Anatomical variance of scapular spine angle and position of Acromion in relation to scapular plane was examined. For comparison of strain as a function of deltoid lengthening, 25 mm was used as a threshold value for comparison based on previous literature demonstrating a decrease in constant score and active anterior elevation in patients with arm lengthening >25 mm. Results At maximal deltoid lengthening (30.8 mm), average strains were 1112μe (Acromion) and 1165μe (SS) (p The strain results delineated 2 anatomical groups: 5/10 specimens (group A) showed higher strain on SS (1445μe) versus Acromion (862μe, p=0.02). Group A had a more posteriorly oriented Acromion, whereas group B was anteriorly oriented (p Conclusion Deltoid lengthening above 25mm produced large strains on the Acromion/scapular spine. Anatomic variation may indicate that as the Acromion is more posteriorly oriented, the SS takes more strain from the deltoid versus the Acromion. Our study’s data may help surgeons identify a high-risk population for increased strain patterns after RSA. Level of Evidence Basic Science Study; Biomechanice

  • Acromion compromise does not significantly affect clinical outcomes after reverse shoulder arthroplasty a matched case control study
    HSS Journal, 2019
    Co-Authors: Brian C Werner, Lawrence V Gulotta, David M Dines, Russell F Warren, Joshua S Dines, Edward V Craig, Samuel A Taylor

    Abstract:

    The effect of a pre-operative compromised Acromion on reverse shoulder arthroplasty (RSA) is not well-studied. We sought to determine the effect of a pre-operative compromised Acromion on outcomes following RSA. We conducted a retrospective case-control study of consecutive patients who underwent RSA over a 6-year period (June 2007 to June 2013) with a diagnosis of rotator cuff tear arthropathy. Pre-operative plain radiographs were examined to determine the presence of Acromion compromise (n = 11). Acromion compromise was defined as (1) less than 25% of the normal Acromion thickness (8.8 mm), (2) less than 50% of the normal Acromion anteroposterior width (46.1 mm), (3) presence of an os acromiale, or (4) presence of acromial fragmentation. An age- and sex-matched control cohort without acromial compromise was also identified (n = 33). The primary outcome variable was the final minimum 2-year American Shoulder and Elbow Surgeons (ASES) score. Secondary outcomes included final minimum 2-year scores on the 12-Item Short-Form Health Survey (SF-12), with the physical component score (PCS) and mental component score (MCS); 2-year Marx shoulder activity scale scores; and final 2-year satisfaction scores. At 2 years post-operatively, there were no significant differences in final scores using ASES, SF-12 PCS or MCS, or Marx shoulder activity scale. There were no significant differences between groups for satisfaction scores in any of the assessed domains. No complications were reported at 2 years’ follow-up in any of the study patients or controls. Between patients with and without pre-operative Acromion compromise, there were no differences in clinical outcomes, satisfaction levels, or complication rates after RSA. Our findings suggest that surgeons performing RSA in the setting of pre-operative Acromion compromise, including os acromiale, acromial fragmentation, or severe thinning, should not expect poor post-operative clinical outcomes.