Michael Stephan Gruber

Dr. Michael Stephan Gruber

Orthopedic Department, Ordensklinikum Linz Barmherzige Schwestern, Linz, Oberösterreich, Austria
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Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 January 2022 in Journal of Clinical Medicine
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Journal Article
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ROReinhold Ortmaier
Reinhold Ortmaier
GWGuido Wierer
Guido Wierer
MGMichael Stephan Gruber
Michael Stephan Gruber
Glenoid implant position and fixation are challenging in severe glenoid defects in reverse total shoulder arthroplasty (rTSA). Custom-made glenoid implants are metal augmented implants that are specially produced for a certain defect. They provide the restoration of the joint line and proper fixation. This retrospective data analysis investigated the clinical and radiological outcomes after revision using custom-made glenoid implants. Between 2018 and 2020, nine patients (10 shoulders) with severe glenoid defects underwent revision rTSA using a custom-made glenoid implant (Materialise Glenius or Lima ProMade). The pre- and postoperative Constant Murley Score (CMS), UCLA Score and Subjective Shoulder Value (SSV) were assessed. Postoperative CT scans and X-rays in two planes were available. The minimum follow-up was 12 months, with a mean follow-up of 23.1 months. The mean preoperative CMS, UCLA Score and SSV were 10.9, 4.1 and 11.0, respectively. The mean postoperative CMS, UCLA Score and SSV showed significant increases of 51.7 (<0.001), 22.9 (<0.001) and 52.0 (<0.001), respectively. There were no signs of loosening implants or scapular notching, and no revision was necessary. This trial showed promising clinical and radiological short-term outcomes for custom-made glenoid components in revision rTSA.

9 January 2020 in The American Journal of Sports Medicine
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PHPhilipp R. Heuberer
Philipp R. Heuberer
LPLeo Pauzenberger
Leo Pauzenberger
MGMichael Stephan Gruber
Michael Stephan Gruber
RORoman C. Ostermann
Roman C. Ostermann
MHMichael Hexel
Michael Hexel
WAWerner Anderl
Werner Anderl
The rotator cuff is known to consist of 2 macroscopically visible layers that have different biomechanical properties. Sometimes the inferior layer may be neglected during rotator cuff repair. However, it is controversial whether double-layer (DL) repair is superior to single-layer (SL) repair in terms of retear rate and outcome. To investigate whether DL as compared with SL repair could decrease retear rates after arthroscopic reconstruction of posterosuperior rotator cuff tears. Randomized controlled trial; Level of evidence, 1. A total of 70 patients were 1:1 randomized to receive an arthroscopic DL reconstruction (study group: DL suture-bridge repair) or SL reconstruction (control group: SL suture-bridge repair) for posterosuperior tears of the rotator cuff between 2.0 and 3.5 cm of the footprint detachment. Exclusion criteria were subscapularis tendon rupture (Lafosse >1°), fatty muscular infiltration >2°, and nondelaminated tendons. Tendon integrity according to Sugaya, fatty degeneration, and muscular atrophy were evaluated by magnetic resonance tomography. Pre- and postoperative evaluations included the Constant score, range of motion, American Shoulder and Elbow Surgeons score, Simple Shoulder Test, subjective shoulder value, and postoperative satisfaction with the procedure. Complications were monitored throughout the study. Ninety percent of patients (n = 34, DL; n = 29, SL) were followed-up. There were no significant group differences regarding baseline characteristics and pre- and postoperative fatty degeneration of the supraspinatus and atrophy of the supraspinatus and infraspinatus. The rate of magnetic resonance–verified intact repairs (Sugaya grades 1 + 2) was significantly higher in the DL group (70.6%) than in the SL group (44.8%; P = .045). One patient in the control group with a retear underwent revision. All functional and subjective scores improved significantly pre- to postoperatively in both groups (P < .05). No significant group differences were detected regarding postoperative Constant score, forward flexion, external rotation, American Shoulder and Elbow Surgeons score, Simple Shoulder Test, subjective shoulder value, and visual analog scale and between intact and retorn tendons. The majority of patients were very satisfied or satisfied with their arthroscopic procedure (DL, 94.1%; SL, 92.9%). This randomized controlled trial showed significantly lower retear rates after DL repair as compared with SL repair in delaminated rotator cuff tears. Clinical short-term outcome was not different between the DL and SL repair groups. NCT003362320 (ClinicalTrials.gov identifier).

6 May 2019 in Knee Surgery, Sports Traumatology, Arthroscopy
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PHPhilipp Richard Heuberer
Philipp Richard Heuberer
LPLeo Pauzenberger
Leo Pauzenberger
MGMichael Stephan Gruber
Michael Stephan Gruber
BKBernhard Kriegleder
Bernhard Kriegleder
RORoman C. Ostermann
Roman C. Ostermann
WAWerner Anderl
Werner Anderl

10 December 2020 in BMC Musculoskeletal Disorders
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Journal Article
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MGMichael Stephan Gruber
Michael Stephan Gruber
MJMichael Jesenko
Michael Jesenko
JBJulia Burghuber
Julia Burghuber
JHJosef Hochreiter
Josef Hochreiter
PRPeter Ritschl
Peter Ritschl
ROReinhold Ortmaier
Reinhold Ortmaier
Background: Severe acetabular defects require special treatment with either impaction bone grafting, metal augmented cups or cup-cage constructs. Even these options are often not adequate, especially in hips with Paprosky type 3 defects with loss of anterior and posterior columns. This study investigates the clinical and radiological outcomes of custom-made acetabular components (© Materialise NV, Leuven, Belgium) for Paprosky type 3 defects. Methods: Sixteen patients were eligible for this trial, nine of whom agreed to be included. All of them completed one year of follow-up. The Harris hip score and the Oxford hip score were used to compare pre- and postoperative functional outcomes. Radiological follow-up comprised anteversion and inclination of the implanted cup and offset measurements in both hips (femoral, medial, ischial offset and center of rotation). Statistical analyses were performed with IBM SPSS Statistics. Results: The mean follow-up time of the nine patients was 12.2 months (range: 10–18). The Oxford hip score and Harris hip score improved from 19.8 and 50.1 to 29.4 and 68.8, respectively (p = 0.009 and 0.01). There were complications in three cases (33.3%), which led to one re-revision (11.1%). Radiologic follow-up showed restoration of the height of the center of rotation and of the global offset. Significant difference was detected in the femoral offset. Conclusions: The functional and radiological outcomes are promising. However, long-term outcomes still need to be examined. Level of evidence: Therapeutic Level IV.

Verified
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MGMichael Stephan Gruber
Michael Stephan Gruber
MBMartin Bischofreiter
Martin Bischofreiter
PBPatrick Brandstätter
Patrick Brandstätter
JHJosef Hochreiter
Josef Hochreiter
Patrick SadoghiPatrick Sadoghi
Patrick Sadoghi
ROReinhold Ortmaier
Reinhold Ortmaier
Rotator cuff tear arthropathy (CTA) is the most common reason for reverse total shoulder arthroplasty (RSA). There is minimal understanding of the natural progression of osteoarthritis of the shoulder and of the morphologic differences between men and women and between younger and older patients. This trial comprised 309 patients (342 shoulders) who underwent RSA due to CTA in the period between January 2009 and September 2019. The patients were divided into gender and age groups. Preoperative X-rays, computed tomography and magnetic resonance imaging were conducted using various classifications to describe the morphology of the CTA. Of all 342 analyzed shoulders, 209 were right and 133 were left shoulders. A total of 257 female shoulders and 85 male shoulders were assessed. Both mean age and age distribution were significantly different (74.37 years in female and 70.11 years in male patients, p = 0.001; 70.2% female patients in the age group 75.5 years, p = 0.045). A larger extent of progression of the fatty infiltration was detected both in the female cohort (p = 0.006) and in the older age group (p = 0.001). Additionally, older patients had significantly higher levels of muscle retraction (Patte; p = 0.003), a lower acromiohumeral distance (p = 0.042) and more advanced CTA (Seebauer; p = 0.006).

7 December 2022 in Journal of Clinical Medicine
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Journal Article
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MGMichael Stephan Gruber
Michael Stephan Gruber
TSTamara Schwarz
Tamara Schwarz
MLMarlene Lindorfer
Marlene Lindorfer
FRFelix Rittenschober
Felix Rittenschober
MBMartin Bischofreiter
Martin Bischofreiter
ROReinhold Ortmaier
Reinhold Ortmaier
Reverse total shoulder arthroplasty presents itself sometimes as challenging when it comes to addressing massive bone loss, either in primary or revision settings. Custom components recently have made their way into shoulder prosthetics and are meant to help in the case of extensive glenoid bone destruction. Because of strict indication and the fairly recent introduction of these implants, the usage of custom-made glenoid implants is not very common yet. However, the early results are promising. The purpose of this review was to summarize and analyze the available literature. Therefore, a systematic review was performed according to PRISMA guidelines. A comprehensive search of the databases PubMed, Cochrane, and Livivo was performed to screen for studies reporting on clinical and radiological outcomes of custom glenoid implants. Four studies with a total of 46 shoulders were included in this review. The mean patient age was 68.8 years and the mean time of follow-up was 24.3 months. The weighted means showed an increase in CMS (32.7 points), in ASES (39.8 points), in anteversion (67.4 degrees), and in abduction (51.9 degrees) and a decrease in VAS (5.4 points). Custom-made glenoid implants are therefore a viable option in cases of large combined glenoid bone loss, both in primary and revision shoulder arthroplasty.