Paul Siegert

Dr. Paul Siegert


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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11 May 2020 in The American Journal of Sports Medicine
Verified
Journal Article
Closed access
PDF file
FPFabian Plachel
Fabian Plachel
PSPaul Siegert
Paul Siegert
KRKatja Rüttershoff
Katja Rüttershoff
KTKathi Thiele
Kathi Thiele
DADoruk Akgun
Doruk Akgun
CGChristian Gerhardt
Christian Gerhardt
Arthroscopic rotator cuff repair (RCR) with suture anchor–based fixation techniques has replaced former open and mini-open approaches. Nevertheless, long-term studies are scarce, and lack of knowledge exists about whether single-row (SR) or double-row (DR) methods are superior in clinical and anatomic results. To analyze long-term results after arthroscopic RCR in patients with symptomatic rotator cuff tears and to compare functional and radiographic outcomes between SR and DR repair techniques at least 10 years after surgery. Cohort study; Level of evidence, 3. Between 2005 and 2006, 40 patients with a symptomatic full-thickness rotator cuff tear (supraspinatus tendon tear with or without a tear of the infraspinatus tendon) underwent arthroscopic RCR with either an SR repair with a modified Mason-Allen suture–grasping technique (n = 20) or a DR repair with a suture bridge fixation technique (n = 20). All patients were enrolled in a long-term clinical evaluation, with the Constant score (CS) as the primary outcome measure. Furthermore, an ultrasound examination was performed to assess tendon integrity and conventional radiographs to evaluate secondary glenohumeral osteoarthritis. A total of 27 patients, of whom 16 were treated with an SR repair and 11 with a DR repair, were followed up after a mean ± SD period of 12 ± 1 years (range, 11-14 years). Five patients underwent revision surgery on the affected shoulder during follow-up period, which led to 22 patients being included. The overall CS remained stable at final follow-up when compared with short-term follow-up (81 ± 8 vs 83 ± 19 points; P = .600). An increasing number of full-thickness retears were found: 6 of 22 (27%) at 2 years and 9 of 20 (45%) at 12 years after surgery. While repair failure negatively affected clinical results as shown by the CS (P < .05), no significant difference was found between the fixation techniques (P = .456). In general, progressive osteoarthritic changes were observed, with tendon integrity as a key determinant. Arthroscopic RCR with either an SR or a DR fixation technique provided good clinical long-term results. Repair failure was high, with negative effects on clinical results and the progression of secondary glenohumeral osteoarthritis. While DR repair slightly enhanced tendon integrity at long-term follow-up, no clinical superiority to SR repair was found.

1 October 2020 in Journal of Shoulder and Elbow Surgery
Verified
Journal Article
Open access
PMPhilipp Moroder
Philipp Moroder
DADoruk Akgün
Doruk Akgün
FPFabian Plachel
Fabian Plachel
ABAlexander Baur
Alexander Baur
PSPaul Siegert
Paul Siegert
The literature suggests implantation of the humeral component in reverse total shoulder arthroplasty (RTSA) in 0°-40° of retrotorsion without further specification. We hypothesized that optimal humeral component retrotorsion to avoid notching and gain balanced rotational capacity would depend on scapular position and posture. We investigated 200 shoulders in 100 patients with available whole-body computed tomography scans and created 3-dimensional models. Implantation of a humeral component in 20° of retrotorsion was simulated, and a correction angle (CA) to yield perfect opposition to the glenosphere was calculated. Patient-specific variables such as age, sex, posture, and scapular orientation parameters were correlated with this CA. Scapular orientation showed large interindividual differences. A highly significant correlation was seen between the CA and scapular internal rotation (R = 0.71, P < .001) and protraction (R = 0.39, P < .001). When the CA was adjusted for glenoid retroversion, the correlation coefficient of scapular internal rotation increased even further (R = 0.91, P < .001). Scapular internal rotation itself showed a correlation with thoracic kyphosis (R = 0.27, P < .001), protraction (R = 0.57, P < .001), tilt (R = 0.29, P < .001), and scapular translation (R = -0.23, P < .001). Scapular orientation and posture should be integrated into the determination process of humeral component retrotorsion in RTSA. In theory, implantation of the humeral component with increased retrotorsion leads to improved neutral opposition of the RTSA components in patients with extensive internal rotation of the scapula. On the basis of varying scapular internal rotation, we propose the distinction of 3 different posture types (A-C) for enhanced appraisal of scapulothoracic orientation.

10 March 2022 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
JFJulia K. Frank
Julia K. Frank
PSPaul Siegert
Paul Siegert
FPFabian Plachel
Fabian Plachel
PHPhilipp Richard Heuberer
Philipp Richard Heuberer
SHStephanie Huber
Stephanie Huber
JSJakob E. Schanda
Jakob E. Schanda
Purpose of Review: The purpose of this review is to summarize recent literature regarding the latest design modifications and biomechanical evolutions of reverse total shoulder arthroplasty and their impact on postoperative outcomes. Recent findings: Over the past decade, worldwide implantation rates of reverse total shoulder arthroplasty have drastically increased for various shoulder pathologies. While Paul Grammont’s design principles first published in 1985 for reverse total shoulder arthroplasty remained unchanged, several adjustments were made to address postoperative clinical and biomechanical challenges such as implant glenoid loosening, scapular notching, or limited range of motion in order to maximize functional outcomes and increase the longevity of reverse total shoulder arthroplasty. However, the adequate and stable fixation of prosthetic components can be challenging, especially in massive osteoarthritis with concomitant bone loss. To overcome such issues, surgical navigation and patient-specific instruments may be a viable tool to improve accurate prosthetic component positioning. Nevertheless, larger clinical series on the accuracy and possible complications of this novel technique are still missing.

20 October 2021 in Clinical Orthopaedics and Related Research
Verified
Journal Article
Open access
PMPhilipp Moroder
Philipp Moroder
MUManuel Meng Urvoy
Manuel Meng Urvoy
PRPatric Raiss
Patric Raiss
JWJean-David Werthel
Jean-David Werthel
DADoruk Akgun
Doruk Akgun
PSPaul Siegert
Paul Siegert
Background: Component selection and placement in reverse total shoulder arthroplasty (RTSA) is still being debated. Recently, scapulothoracic orientation and posture have emerged as relevant factors when planning an RTSA. However, the degree to which those parameters may influence ROM and whether modifiable elements of implant configuration may be helpful in improving ROM among patients with different postures have not been thoroughly studied, and modeling them may be instructive. Questions/purposes: Using a dedicated expansion of a conventional preoperative planning software, we asked: (1) How is patient posture likely to influence simulated ROM after virtual RTSA implantation? (2) Do changes in implant configuration, such as humeral component inclination and retrotorsion, or glenoid component size and centricity improve the simulated ROM after virtual RTSA implantation in patients with different posture types? Methods: In a computer laboratory study, available whole-torso CT scans of 30 patients (20 males and 10 females with a mean age of 65 ± 17 years) were analyzed to determine the posture type (Type A, upright posture, retracted scapulae; Type B, intermediate; Type C, kyphotic posture with protracted scapulae) based on the measured scapula internal rotation as previously described. The measurement of scapular internal rotation, which defines these posture types, was found to have a high intraclass correlation coefficient (0.87) in a previous study, suggesting reliability of the employed classification. Three shoulder surgeons each independently virtually implanted a short, curved, metaphyseal impaction stem RTSA in each patient using three-dimensional (3D) preoperative surgical planning software. Modifications based on the original component positioning were automatically generated, including different humeral component retrotorsion (0°, 20°, and 40° of anatomic and scapular internal rotation) and neck-shaft angle (135°, 145°, and 155°) as well as glenoid component configuration (36-mm concentric, 36-mm eccentric, and 42-mm concentric), resulting in 3720 different RTSA configurations. For each configuration, the maximum potential ROM in different planes was determined by the software, and the effect of different posture types was analyzed by comparing subgroups. Results: Irrespective of the RTSA implant configuration, the posture types had a strong effect on the calculated ROM in all planes of motion, except for flexion. In particular, simulated ROM in patients with Type C compared with Type A posture demonstrated inferior adduction (median 5° [interquartile range -7° to 20°] versus 15° [IQR 7° to 22°]; p < 0.01), abduction (63° [IQR 48° to 78°] versus 72° [IQR 63° to 82°]; p < 0.01), extension (4° [IQR -8° to 12°] versus 19° [IQR 8° to 27°]; p < 0.01), and external rotation (7° [IQR -5° to 22°] versus 28° [IQR 13° to 39°]; p < 0.01). Lower retrotorsion and a higher neck-shaft angle of the humeral component as well as a small concentric glenosphere resulted in worse overall ROM in patients with Type C posture, with severe restriction of motion in adduction, extension, and external rotation to below 0°. Conclusion: Different posture types affect the ROM after simulated RTSA implantation, regardless of implant configuration. An individualized choice of component configuration based on scapulothoracic orientation seems to attenuate the negative effects of posture Type B and C. Future studies on ROM after RTSA should consider patient posture and scapulothoracic orientation. Clinical Relevance: In patients with Type C posture, higher retrotorsion, a lower neck-shaft angle, and a larger or inferior eccentric glenosphere seem to be advantageous.

1 June 2020 in Journal of Shoulder and Elbow Surgery
Verified
Journal Article
Closed access
DADoruk Akgun
Doruk Akgun
NMNina Maziak
Nina Maziak
FPFabian Plachel
Fabian Plachel
PSPaul Siegert
Paul Siegert
MMMarvin Minkus
Marvin Minkus
PMPhilipp Moroder
Philipp Moroder

25 March 2024 in Journal of Shoulder and Elbow Surgery
Verified
Journal Article
Closed access
PMPhilipp Moroder
Philipp Moroder
PSPaul Siegert
Paul Siegert
ICIsmael Coifman
Ismael Coifman
KRKatja Rüttershoff
Katja Rüttershoff
GSGiovanni Spagna
Giovanni Spagna
LALaurent Audigé
Laurent Audigé