Biomedical subjects

Markus Knupp

Publications and source records attributed to Markus Knupp.

6 recordsLinked to original sources

PubMed2006

Effects of a preload on reduction of food intake by GLP-1 in healthy subjects.

BACKGROUND/AIMS: Glucagon-like peptide-1 (GLP-1) inhibits food intake in animals and humans. Whether GLP-1 interacts with other satiety signals to modulate food intake is unknown. We investigated therefore in healthy volunteers the potential interactions of GLP-1 with signals from the stomach in regulating food intake. METHODS: Three sequential, double-blind, crossover studies were performed in male subjects: (1) 12 subjects underwent four experiments (preloads) 20 min before meal intake; (2) 12 volunteers received intravenous (i.v.) GLP-1 (0.9 pmol/kg/min) or saline; (3) subjects received i.v. GLP-1 or saline (control) together with a preload of either 400 ml water or 400 ml protein shake. The effect of these treatments on food intake and feelings of hunger was quantified. Subjects were free to eat and drink as much as they wished. RESULTS: GLP-1 induced a reduction in food and calorie intake (p < 0.005) compared to controls. If combined with a protein preload, the inhibitory effect of GLP-1 on food intake was markedly increased (p < 0.001). Furthermore, a decrease in hunger feelings and an increase in satiety feelings was documented. CONCLUSION: GLP-1 interacts with signals from the stomach to modulate energy intake in humans. The signal is only initiated by nutrient-based distension, but not with gastric distension of the fundus alone.

Adult↗

PubMed2006

Sports and recreation activity of ankle arthritis patients before and after total ankle replacement.

BACKGROUND: Total ankle replacement is a possible treatment for ankle arthritis; however, participation in sports after this procedure has not yet been analyzed. HYPOTHESES: There is a significant increase of sports activity after total ankle replacement in patients with arthritis. There is a significant correlation between sports activity and American Orthopaedic Foot and Ankle Society hindfoot score in patients after total ankle replacement. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A clinical evaluation was performed preoperatively and at follow-up after total ankle replacement in 147 patients (152 ankles) with ankle arthritis (mean age, 59.6 years; range, 28-86 years). Ankle arthritis origin, patient satisfaction, range of motion, American Orthopaedic Foot and Ankle Society hindfoot score, radiologic assessment, and rate, level, and type of sports activity were documented at both evaluations. The mean follow-up was 2.8 years (range, 2-4 years). RESULTS: Preoperative diagnosis was posttraumatic osteoarthritis in 115 cases (76%). At total ankle replacement follow-up, excellent and good outcomes were reported in 126 cases (83%); 105 cases (69%) were pain free. The mean range of motion pre-operatively was 21 degrees (range, 0 degrees -45 degrees ); after total ankle replacement, it was 35 degrees (range, 10 degrees -55 degrees ; P < .05). The preoperative American Orthopaedic Foot and Ankle Society score was 36 points; after total ankle replacement, it was 84 points (P < .001). Before surgery, 36% of the patients were active in sports; after surgery, this percentage rose to 56% (P < .001). After total ankle replacement, sports-active patients showed a significantly higher hindfoot score than did patients not active in sports: 88 versus 79 points (P < .001). The 3 most frequent sports activities were hiking, biking, and swimming. CONCLUSION: There was a significant increase of sports activity by treating ankle arthritis patients with total ankle replacement. Sports-active total ankle replacement patients showed better functional results than did inactive ones.

Adult↗

PubMed2006

Operative management of chronic ankle instability: plantaris graft.

Precise knowledge of lateral ankle ligaments anatomy and biomechanics is mandatory for successful surgical reconstruction. The displayed reconstruction procedure fulfilled these requirements, and showed excellent clinical outcome. The described harvesting of the plantaris tendon at the proximal calf allows the use of a relatively long tendon autograft compared with the traditional harvesting procedure at the os calcis. Consequently, this procedure gives the surgeon a more efficient access to a local tendon autograft for numerous surgical procedures in the field of foot and ankle surgery.

Ankle Joint↗

PubMed2006

Deltoid ligament injuries: diagnosis and management.

The medial ligaments of the ankle are injured more often than generally believed. Complete deltoid ligament tears are occasionally seen in association with lateral malleolar fractures or bimalleolar fractures. Chronic deltoid ligament insufficiency can be seen in several conditions, including posterior tibial tendon disorder, trauma- and sports-related deltoid disruptions, and valgus talar tilting in patients who have a history of triple arthrodesis or total ankle arthroplasty. This article focuses on the anatomy and function of the medial ligaments of the ankle and establishes a rationale for the diagnosis and treatment of incompetent deltoid ligament.

Ankle Injuries↗

PubMed2006

Evaluation of hindfoot dimensions: a radiological study.

BACKGROUND: Realignment of the foot and good ligament balancing are mandatory for successful reconstruction of complex hindfoot disorders. This is why references for restoration of the normal anatomy and function are necessary when considering surgical reconstruction, such as osteotomies, arthrodeses, and total ankle replacement. However, no data are available regarding the normal anatomical dimensions on standard radiographs of the hindfoot. The purpose of this radiographic study was to define relevant and reproducible measures on lateral hindfoot radiographs and to assess their reliability. METHODS: Lateral radigraphic views were taken of 100 consecutive patients (37 women, 63 men) who consulted the emergency room for foot trauma. Dimensions assessed were the talar coverage by the tibia, the angle of the distal tibial joint plane to the tibial axis (tilt), the width of the tibia, the height of the talus, the joint radius of the ankle joint, and the offset of the center of rotation from the tibial axis. RESULTS: The tibial coverage of the talus was 88.1 (SD = 6.7) degrees, the tibial tilt was 83 (SD = 3.6) degrees, the width of the distal tibia was 33.6 mm (SD = 3.6 mm), the radius of the ankle joint was 18.6 mm (SD = 2.3 mm) with an anterior offset of the center of rotation of 1.7 mm (SD = 2.1 mm), and the height of the talus was 28.2 mm (SD = 4.0 mm). CONCLUSIONS: Several easily accessible measures on radiographs were found to be reliable in describing normal hindfoot anatomy and therefore may be used to evaluate hindfoot disorders. Additionally, because any reconstruction of the hindfoot should aim to correct the feet in a physiological way, these references may be helpful in the preoperative planning for treatment of complex deformities and posttraumatic disorders.

Adolescent↗

PubMed2005

The surgical tibiotalar angle: a radiologic study.

BACKGROUND: Many studies on cadaver specimens describe the hindfoot anatomy, but few measures have been defined and quantified on radiographs. Our aim was to determine the tibiotalar angle using the tibial tuberosity as a reference point. METHODS: The tibiotalar angle, using the tibial tuberosity as reference point, was measured on anteroposterior views of 168 ankles. Bilateral radiographs were obtained in 75 patients. RESULTS: The tibiotalar angle was 92.4 degrees (SD = 3.1) without significant intraindividual difference on the radiographs examined bilaterally. More varus was found in women and with increased age. CONCLUSIONS: The tibial tuberosity is a reliable reference point for the measurement of the tibiotalar angle and is used in numerous operative procedures of the hindfoot. If the angle cannot be measured because of progressed destruction, the measurement can be obtained from the contralateral leg, as no significant intraindividual difference was found in the tibiotalar angle (p < 0.001).

Adult↗