Mepitel: re-application after rinsing?
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Biomedical subjects
Publications and source records attributed to M J P F Ritt.
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BACKGROUND: Adipose tissue contains a stromal vascular fraction that can be easily isolated and provides a rich source of adipose tissue-derived mesenchymal stem cells (ASC). These ASC are a potential source of cells for tissue engineering. We studied whether the yield and growth characteristics of ASC were affected by the type of surgical procedure used for adipose tissue harvesting, i.e. resection, tumescent liposuction and ultrasound-assisted liposuction. METHODS: Frequencies of ASC in the stromal vascular fraction were assessed in limiting dilution assays. The phenotypical marker profile of ASC was determined, using flow cytometry, and growth kinetics were investigated in culture. ASC were cultured under chondrogenic and osteogenic conditions to confirm their differentiation potential. RESULTS: The number of viable cells in the stromal vascular fraction was affected by neither the type of surgical procedure nor the anatomical site of the body from where the adipose tissue was harvested. After all three surgical procedures, cultured ASC did express a CD34+ CD31- CD105+ CD166+ CD45- CD90+ ASC phenotype. However, ultrasound-assisted liposuction resulted in a lower frequency of proliferating ASC, as well as a longer population doubling time of ASC, compared with resection. ASC demonstrated chondrogenic and osteogenic differentiation potential. DISCUSSION: We conclude that yield and growth characteristics of ASC are affected by the type of surgical procedure used for adipose tissue harvesting. Resection and tumescent liposuction seem to be preferable above ultrasound-assisted liposuction for tissue-engineering purposes.
Complex fracture dislocations of the wrist often result in post-traumatic arthrosis. In these cases, patients can experience severe pain and loss of function of the wrist and as a result many of them end up having a total arthrodesis. In trying to avoid the disadvantages of a total arthrodesis, alternative treatment strategies have been investigated, amongst which proximal row carpectomy (PRC). Basic conditions for a good outcome of PRC are an intact cartilage of the lunate fossa of the distal radius and an intact surface of the head of the capitate for the new radiocapitate joint (, schematic drawing post-PRC). Also, an intact (volar) radioscaphocapitate (RSC) ligament is necessary because it plays an essential role in stabilizing the new joint and preventing volar dislocation and ulnar translocation of the distal carpal row. Acute post-traumatic PRC can be indicated, but is rarely reported in literature. In this article, we present four patients whom we have treated with early PRC after severe trauma of the wrist. Three patients had a good outcome. In the patient with the bad outcome, the before-mentioned prerequisites were not met, which is discussed.
In the last decade, transsexual patients have increasingly sought sex reassignment (cross-sex hormones and sex reassignment surgery), whilst avoiding adequate diagnostic procedures. They ask non-specialized physicians to prescribe hormones or to perform sex reassignment surgery. Sometimes hormones are ordered through the Internet or obtained from other illegitimate sources. If these patients later turn to a specialized team (for instance for sex reassignment surgery), the obligatory standard diagnostic procedure is problematic: the patient does not accept having to go through a long period of assessment and objective decisionmaking, while the attending health professional feels pressured by the patient's impatience. Non-expert health professionals should draw patients' attention to the necessity of a thorough diagnostic procedure, thus avoiding wrong decisions and future regrets.
The standard technique for bridging a peripheral nerve defect is an autologous nerve graft if the nerve ends cannot be sutured. Recent evidence indicates that an alternative procedure-application of a degradable nerve guide-may be feasible. Currently the use of such a degradable nerve guide for the recovery of peripheral nerve defects in the hand is being tested in a multicenter trial. Conventional suturing as well as autologous nerve grafting are accepted methods in the control group within the protocol of the multicenter study. In the first two patients to receive the implant, a 28-year-old man and a 50-year-old women with tendon and nerve injury due to glass cuts, the operation was technically successful. Functional nerve recovery will be assessed in due course.
A retrospective survey of the medical charts of all 36,518 patients attending the Accident and Emergency Department of the VU University Medical Centre, in Amsterdam, from January 1 to December 31, 1996 was performed. Of these, 4303 sustained one or more fractures, and hand fractures accounted for 19% of all fractures. Patients with hand fractures were typically men aged between 15 and 35 years. The right hand was involved as often as the left. Most of the hand fractures involved the metacarpals but, as a group of bones, the combined phalanges were most commonly fractured. The little finger ray was most commonly injured of the hand. We found no seasonal variability in the incidence of hand fractures.
OBJECTIVE: The purpose of this study was to accurately quantify three-dimensional in vivo kinematics of all carpal bones in flexion and extension and radial and ulnar deviation. DESIGN AND METHODS: The right wrists of 11 healthy volunteers were imaged by spiral CT with rotational increments of 5 degrees during ulnar-radial deviation and of five of them also during flexion-extension motion. One regular-dose scan was used and the subsequent scans during wrist motion were performed with one-tenth of the regular dose. A three-dimensional matching technique using the internal structure of the bones was developed to trace the relative translations and rotations of the carpal bones very accurately. RESULTS: Most of our results are in concordance with previously published in vitro data. We could, among others, substantiate proof to the statement that there is more than one kinematic pattern of the scaphoid. Furthermore, we could accurately describe small adaptive intercarpal motions in vivo of the distal carpal row. CONCLUSIONS: To our knowledge, this is the first time the three-dimensional in vivo kinematics of all eight carpal bones is quantified accurately and non-invasively. RELEVANCE: Kinematics of an injured wrist can be compared to these reference data. It may become possible that in this way a ligament lesion can be detected with high specificity and sensitivity, and that no other diagnostic modality will be needed. With these data we made animations with which the complex movements of the bones during different motions of the wrist can be viewed. In the future it may become possible that this analysis provides valuable information on the long-term results of operative interventions and possibly predicts results of operative techniques.
OBJECTIVE: To investigate the constraint and potential mechanism of torque transmission across the wrist joint. DESIGN: In vitro experiment using human cadaveric specimens. BACKGROUND: Transmission of torque from the forearm to the hand requires rotational stability at the wrist. Better appriciation of the constraints would have applicability to several clinical problems where the stability is compromised. METHODS: Thirteen fresh-frozen cadaveric specimens were used in this experiment to investigate the rotational laxity and stiffness of the radiocarpal joint in unloaded and axially loaded (100 N) conditions, and three forearm orientations in a neutral, pronation (60 degrees ), or supination (60 degrees ) position. RESULTS: In pronation or supination, there was no difference between loaded and unloaded conditions in primary or total laxity at a maximum torque of 2.3 Nm. Unloaded specimens showed a mean total rotational laxity of 42.1 degrees. Supination or pronation of the forearm caused a decrease in laxity with respect to neutral forearm rotation (35 degrees and 41.6 degrees versus 49.6 degrees respectively). The primary rotational laxity accounted for half of the total laxity. With axial compression, total rotational laxity did not change, but primary laxity dropped to 50% of its unloaded value. The primary stiffness was very low -- approximately 11% of the secondary stiffness. CONCLUSION: The ligamentous structures and the joint articulation restricted excessive axial rotation of the wrist. However, a laxity of approximately 20 degrees was identified for normal wrists. RELEVANCE: This study demonstrated that the primary axial rotational laxity of the radiocarpal joint was approximately 20 degrees. In the mathematical model and implant design, muscular balance of the joint within such laxity should be considered.
The use of early mobilization during rehabilitation of a finger after flexor tendon repair in zone II has achieved worldwide acceptance. Different exercise instructions are given to patients in different clinics, however. When using Kleinert dynamic splinting, some hand therapists instruct patients to exercise 10 times an hour, while others tell their patients to exercise as many times as possible. How often a patient should exercise to achieve optimal results has never, to the authors' knowledge, been investigated. To identify a relationship between exercise behavior and range of motion achieved at 6 months postoperatively, the authors started a pilot study of the compliance of 15 patients with a rehabilitation program following flexor tendon repair in zone II. A portable rehabilitation device was used to deliver an isotonic tensile force and to record when (during the day) a patient exercises and how many exercises the patient performs. Patients were instructed to perform at least ten exercises per hour. The average count per hour was 69 exercises (range, 14-213). In this small group study, no strong correlation was found between exercise count and the total active or total passive motion achieved.