Clemens Memmel

Dr. Clemens Memmel

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Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

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

Representative Publications

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CMClemens Memmel
Clemens Memmel
WKWerner Krutsch
Werner Krutsch
DSDominik Szymski
Dominik Szymski
CPChristian Pfeifer
Christian Pfeifer
LHLeopold Henssler
Leopold Henssler
MKMatthias Koch
Matthias Koch
Background: Although anterior cruciate ligament reconstruction (ACLR) is a well-established procedure and is standardly performed by orthopedic surgeons all over the world, there does not seem to be a standard protocol for early rehabilitation. The purpose of this study was to give answers to the following questions: (i) Does (a) the use of a specific tendon graft, and (b) potentially additional therapy of concomitant pathologies influence surgeons’ choice of a distinct postoperative rehabilitation protocol after ACLR? (ii) To what extent do these rehabilitation recommendations differ? Methods: Retrospective analysis of currently used early rehabilitation protocols after ACLR in German-speaking countries (GER, AUT and SUI) was conducted. Rehabilitation criteria included weight bearing, range of motion (ROM), the utilization of braces, continuous passive/active motion therapy (CPM/CAM), rehabilitation training and sport-specific training. Tendon grafts were differentiated as hamstring (HAM) and bone–patellar tendon–bone grafts (BTB). Concomitant pathologies included meniscus injuries (+M) and unhappy triad injuries (+UTI). Results: Most of the surveyed protocols were differentiated according to the used tendon graft or additional therapy of concomitant injuries (ACLR-differentiated, n = 147 vs. ACLR without graft differentiation, n = 58). When comparing ACLR-HAM and ACLR-BTB, significant differences were found regarding weight bearing (p = 0.01), ROM (p = 0.05) and the utilization of braces (p = 0.03). Regarding ACLR+M, an overall significant decelerated rehabilitation could be detected. After ACLR+UTI-therapy, a significant delayed start to full weight bearing (p = 0.002) and ROM (p < 0.001) was found. Conclusions: Most orthopedic surgeons from German-speaking countries differentiate early rehabilitation after ACLR according to the tendon graft used and therapy of concomitant pathologies. No consensus about early rehabilitation after ACLR is available. However, tendencies for an accelerated rehabilitation after ACLR-BTB and a more restrained rehabilitation of multiple injured knees were detected.

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CMClemens Memmel
Clemens Memmel
MKMatthias Koch
Matthias Koch
DSDominik Szymski
Dominik Szymski
LHLorenz Huber
Lorenz Huber
CPChristian Pfeifer
Christian Pfeifer
WKWerner Krutsch
Werner Krutsch
(1) Background: Isolated posterior cruciate ligament (PCL) tears represent a severe type of injury. In hospitals, PCL reconstruction (PCL-R) is less frequently performed than other types of knee surgery. It is unclear whether there is consensus among surgeons on how to perform rehabilitation after PCL-R or if there are different, more individual approaches in daily routines. (2) Methods: Rehabilitation protocols and their main criteria (the progression of weight bearing and range of motion, the use of knee braces, rehabilitation training, and sports-specific training) were retrospectively analyzed after PCL-R. (3) Results: Only 33 of 120 (27.5%) analyzed institutes use rehabilitation protocols after PCL-R. The applied protocols showed vast differences between the individual rehabilitation criteria, especially with regard to the progression of weight bearing and the range of motion. The only standardized recommendations were the obligatory use of knee braces and the general restriction of weight bearing and range of motion immediately post-surgery. Therefore, because of the lack of a consensus about a standardized rehabilitation protocol after PCL-R, no recommendation can be made on one particular protocol. (4) Conclusion: There is no acknowledged standardized rehabilitation protocol after PCL-R. In clinical practice, recommendations are influenced by, i.a., surgeons’ opinions and experience. The lack of scientific evidence on a particular standardized rehabilitation protocol after PCL-R suggests that rehabilitation protocols need to be tailored to the individual patient.

24 September 2021 in Applied Sciences
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CMClemens Memmel
Clemens Memmel
WKWerner Krutsch
Werner Krutsch
MKMatthias Koch
Matthias Koch
MRMoritz Riedl
Moritz Riedl
LHLeopold Henssler
Leopold Henssler
CPChristian Pfeifer
Christian Pfeifer
The present study analysed current rehabilitation protocols to investigate whether there is a standard for early rehabilitation after microfracturing (MFX), matrix-assisted cartilage transplantation (MACT), and osteochondral autograft transfer (OATS) of the knee joint in clinical routine, and if rehabilitation protocols differ in the repair technique used or the localization of the cartilage defect. The evaluation included rehabilitation criteria such as weight-bearing, range of motion, use of an orthosis, motion therapy, and rehabilitation training during the early rehabilitation phase after MFX, MACT, and OATS of the femorotibial and retropatellar joint space. We analysed 153 rehabilitation protocols after cartilage repair of the knee joint, including 137 protocols for after repair of the main weight-bearing (femorotibial) area and 16 for after retropatellar cartilage repair. Most of the protocols differed significantly according to the location of the repair and the procedure performed. Our findings indicate that full weight-bearing can be achieved significantly faster after MFX (5.6 weeks) and OATS (5.3 weeks) than after MACT of the main weight-bearing zone (6.6 weeks, p < 0.001). In addition, after retropatellar cartilage repair, patients are allowed full weight-bearing after 2.1 weeks compared to the main weight-bearing zone (5.3–6.6 weeks; p < 0.001). No standardized rehabilitation recommendations have been established. The present study shows that rehabilitation needs to be adjusted to the surgical technique and the location of the defect zone, and further investigation is warranted to establish standardized rehabilitation protocols after cartilage repair of the knee joint.

6 July 2023 in Applied Sciences
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CMClemens Memmel
Clemens Memmel
ADAndré Denzlein
André Denzlein
DSDominik Szymski
Dominik Szymski
LHLorenz Huber
Lorenz Huber
LALeonard Achenbach
Leonard Achenbach
MKMatthias Koch
Matthias Koch
The prevalence of varus knee malalignment among junior and adult football players (FP) has proven to be higher compared to other sports. No causal relationship has yet been found, as genu varum can be assumed to be an independent risk factor for the development of knee osteoarthritis. The purpose of this study is to compare knee alignment measurements and sport-specific data of adolescent football players and referees (REF). Knee alignment was detected by measuring the intercondylar/intermalleolar distance (ICD/IMD) as well as the Hip–Knee–Ankle angle (HKA) using a standardized digital frontal-plane photograph. Anthropometric and sports-related data (training/match exposure, seasons actively played, etc.) were collected by means of questionnaires (Clinical trial registration number: DRKS00020446). A total of 28 male FP and 29 male adolescent REF were included in the survey. The mean age was 17.4 ± 0.7 years. The two groups did not differ significantly in age, height, weight, BMI, and overall football/refereeing exposure per week (FP vs. REF: 274 vs. 285 min/week, p = 0.61). The HKA of the FP was significantly lower (toward varus) than that of the REF (177.6° ± 2.4° vs. 179.0° ± 2.4°; p < 0.001). However, ICD did not significantly differ (FP: 17 ± 25 mm, REF: 13 ± 27 mm; p = 0.55). The football environment with frequent football exposure seems to have an influence on leg axis deviation in FP compared to REF. For prevention of knee osteoarthritis in FP, an advanced understanding of leg axis development in adolescent players is essential and, therefore, needs further research.

7 August 2024 in Children
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CMClemens Memmel
Clemens Memmel
DSDominik Sporrer
Dominik Sporrer
DSDominik Szymski
Dominik Szymski
JWJohannes Weber
Johannes Weber
AHAlexander Hanke
Alexander Hanke
MKMatthias Koch
Matthias Koch
Background: Football, as the most popular sport worldwide, has long been under suspicion of causing varus knee alignment as early as adolescence. However, no causal relationship has yet been found. The first step to do so would be to determine the prevalence of lower leg malalignment among male junior football players depending on age, performance level and the number of active seasons played. Methods: Leg axis alignment in frontal plane was determined in male junior football players of different age levels between 7 and 18 years by measuring the intercondylar/intermalleolar distance (ICD/IMD) in an upright position. In addition to anthropometric data, multiple sport-specific data such as the start of their football career or training time per week were collected by means of questionnaires (clinical trial registration number: DRKS00020446). Results: 207 male junior football players were included in this survey. The mean age was 12.8 years. Within the group of 15 to 18 year olds, the prevalence of varus knee malalignment was highest at just under a third (32.1%). In the subpopulation that played actively for more than ten seasons, 28.9% showed varus leg axis. Regarding performance level, the highest IMD/ICD values and highest prevalence of varus alignment were found among football players who play on a semi-professional level (16.7%), compared to amateur (11.4%) and high-performance levels (2.8%). Conclusions: Further research is necessary to investigate if this high prevalence of varus knee in children of a higher age and higher playing levels is due to the selection bias of football players with varus knee or a real development of varus knee in individuals.

30 March 2023 in Applied Sciences
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CMClemens Memmel
Clemens Memmel
LLLisa Lehner
Lisa Lehner
OLOliver Loose
Oliver Loose
CGChristian Gündisch
Christian Gündisch
VKVolker Krutsch
Volker Krutsch
SGStephan Gerling
Stephan Gerling
Pre-participation screening (PPS) in professional junior football is common practice. However, football players (FP) from non-professional football clubs may also be exposed to health risks, both internal and musculoskeletal. Therefore, the Bavarian Football Association (BFV) implemented a cardiological and orthopedic screening program for semi-professional FP in 2014. The purpose of this study was to obtain and present epidemiological data of pre-adolescent and adolescent semi-professional FP, including cardiac pathologies, past injuries, and orthopedic disorders. This study represents a retrospective analysis of semi-professional FP aged 11 to 14 years participating in the PPS program from 2014 to 2018, including their medical history, cardiac risk profiles, and the results of undergoing orthopedic and sports cardiology examinations. Overall, 362 male and 162 female FP could be included. More than 20% of the FP indicated suffering from one or more medical conditions. Cardiac abnormalities were reported in 30 (5.7%) FP. Further cardiological diagnostics were recommended for 3% of the FP due to findings while undergoing the PPS. Orthopedic disorders could be detected in 51 (9.7%) FP. Of the reported injuries, 44.3% could be categorized as overuse injuries. In order to guarantee extensive preventive sports medical care for semi-professional junior FP, a PPS concept should include a basic orthopedic examination in addition to cardiological screening due to a high rate of overuse injuries and cardiac abnormalities among pre-adolescent and adolescent FP. Further studies are needed in junior football to gain epidemiological data on injury occurrence and cardiac abnormalities on an amateur level to evaluate possible PPS programs, even on an amateur level.