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2.
Handchir Mikrochir Plast Chir ; 55(6): 450-456, 2023 Dec.
Article in German | MEDLINE | ID: mdl-37918819

ABSTRACT

INTRODUCTION: The process of continuous acquisition of surgical expertise is a key element in registrar training. The principle of active, self-directed learning, which is regularly applied in medical school, can also be used to gain surgical expertise in registrar training. METHODS: Surgical training can be compared to acquiring expertise in music or sport, where both intellectual and manual capabilities are required. Specific training principles, including analysis, goal setting, practice and reflection on the process, are commonly encountered in these fields. Smart goal setting is preferred in order to ensure compliance and a successful strategy. This can also be used in plastic surgery training. APPLICATION: Surgical principles as well as partial or complete surgical procedures can be practiced using the smart principle. The fragmentation of a larger task into smaller units allows rapid acquisition of surgical expertise without impeding patient safety. DISCUSSION: Surgical training today happens in a setting caught between economic and medicolegal challenges. The reduction of case load requires simulation practice as well as self-directed learning - which has been shown to improve outcomes. The smart principle allows distinct goal setting which can improve compliance of the student and increase success. As this form of learning is not intuitive to all individuals, supervisors and mentor can support trainees in the acquisition of surgical expertise using this principle.


Subject(s)
Internship and Residency , Plastic Surgery Procedures , Surgery, Plastic , Humans , Goals , Students , Clinical Competence
3.
Commun Med (Lond) ; 2(1): 164, 2022 Dec 22.
Article in English | MEDLINE | ID: mdl-36550296

ABSTRACT

BACKGROUND: Traumatic separation of the pubic symphysis can destabilize the pelvis and require surgical fixation to reduce symphyseal gapping. The traditional approach involves open reduction and the implantation of a steel symphyseal plate (SP) on the pubic bone to hold the reposition. Despite its widespread use, SP-fixation is often associated with implant failure caused by screw loosening or breakage. METHODS: To address the need for a more reliable surgical intervention, we developed and tested two titanium cable-clamp implants. The cable served as tensioning device while the clamp secured the cable to the bone. The first implant design included a steel cable anterior to the pubic symphysis to simplify its placement outside the pelvis, and the second design included a cable encircling the pubic symphysis to stabilize the anterior pelvic ring. Using highly reproducible synthetic bone models and a limited number of cadaver specimens, we performed a comprehensive biomechanical study of implant stability and evaluated surgical feasibility. RESULTS: We were able to demonstrate that the cable-clamp implants provide stability equivalent to that of a traditional SP-fixation but without the same risks of implant failure. We also provide detailed ex vivo evaluations of the safety and feasibility of a trans-obturator surgical approach required for those kind of fixation. CONCLUSION: We propose that the developed cable-clamp fixation devices may be of clinical value in treating pubic symphysis separation.


Life-threatening pelvic injuries are often associated with disruption of a joint within the hip bones, called the pubic symphysis. Disruption can lead to a gap and subsequent instability of the pelvis. The current treatment is to stabilize the joint with a steel plate and screws, however this often becomes unstable soon after the operation. In this study, we analyzed two alternatives for stabilization that use cables and clamps instead of the plate. Further, we tested a surgical approach for implantation. The cables and clamps were as stable as a steel plate so offer an alternative approach to stabilize the pubic symphysis.

4.
Oper Orthop Traumatol ; 34(5): 372-378, 2022 Oct.
Article in German | MEDLINE | ID: mdl-35644812

ABSTRACT

OBJECTIVE: Soft tissue reconstruction of complex defects of the lower abdomen, groin, the perineum and the hip region present a reconstructive challenge. Besides free tissue transfer, pedicled flaps may also be utilized. Harvest of the vertical rectus abdominis flap causes a functional deficit by weakening the abdominal wall. Pedicled, perforator-based flaps minimize functional deficits by preserving muscle. INDICATIONS: Soft tissue defects with exposed vital structures, prosthetic devices or irradiated wound beds. CONTRAINDICATIONS: Previous surgery at the donor site, peripheral vascular disease at the pelvic and thigh region, previous vascular interventions at the donor site. SURGICAL TECHNIQUE: After preoperative localization of the perforators, a retrograde, intramuscular dissection of the pedicle allows sufficient length to be gained in order to transpose the flap into the defect. Tunneling of the flap beneath the rectus femoris muscle and Sartorius muscle is often required for tension-free inset. POSTOPERATIVE MANAGEMENT: Five days of bed-rest postoperatively followed by ambulation. RESULTS: No complete flap loss was encountered in 13 cases. In 2 cases a partial tip necrosis required secondary skin grafting.


Subject(s)
Perforator Flap , Plastic Surgery Procedures , Groin/surgery , Humans , Perforator Flap/surgery , Perineum/surgery , Surgical Flaps , Thigh/surgery , Treatment Outcome
5.
Unfallchirurg ; 124(5): 366-372, 2021 May.
Article in German | MEDLINE | ID: mdl-32935138

ABSTRACT

BACKGROUND: Photographic documentation of wounds, decubitus ulcers, tumors, open fractures and infections is an important part of digital patient files. It is unclear whether the photographic documentation has an effect on medical accounting with health insurance companies. OBJECTIVE: It was hypothesized that Smartphone-based systematic photographic documentation can improve the confirmation of proceeds-relevant diagnoses and procedures as well as the duration. MATERIAL AND METHODS: Staff in the emergency room, operating theater, outpatient clinic and on the wards were equipped with digital devices (Smartphone, tablet) including a photo-app. Medical accounting with the health insurance companies and identification of all case conferences in which the photographic documentation had effected a change in proceeds were analyzed for 2019 in a retrospective manner. RESULTS: Overall, 372 cases were discussed of which 27 cases were affected by the digital photographic documentation. Photographic documentation was used for clarification of the operative procedure (n = 5), primary diagnosis (n = 10), secondary diagnosis (n = 3), and length of hospitalization (n = 9). An average of 2119 € was negotiated and added per case affected by photographic documentation. Hereby, a level 1 trauma center gained an estimated 65,328 € in revenue. DISCUSSION: The use of Smartphone based photographic documentation can improve the overall quality of patient files and thus avoid loss of revenue. The implementation of digital devices with corresponding software is an important component of the digital structural change in hospitals.


Subject(s)
Smartphone , Surgery, Plastic , Documentation , Humans , Photography , Retrospective Studies
6.
Handchir Mikrochir Plast Chir ; 52(4): 272-279, 2020 Aug.
Article in German | MEDLINE | ID: mdl-32823363

ABSTRACT

BACKGROUND: To manage the expected COVID-19 patient load major restrictions in in- and outpatient treatment had to be made. Depending on local conditions and order supply differences SARS-CoV-2 restrictions had a massive impact on medical care. To show the impact of plastic surgery on emergency surgery during SARS-CoV-2 pandemic, the amount of surgical emergencies in a single center plastic surgery division were evaluated. METHOD: The number of plastic surgery cases in a university hospital was evaluated during 16.03.2020 to 27.04.2020 and compared with previous years. RESULTS: Due to cancelling of elective surgery the number of cases dropped to 57,3 % of the caseload of previous years. There was no change in ratio of emergency (2020: 56,4 %; 2017-2019: 54,9 %) and urgent (2020: 44,6 %; 2017-2019: 45 %) surgery. No changes in regard to the etiology of trauma cause nor insurance status (occupational insurance/health insurance) were noted. CONCLUSION: Based on the data of this evaluation there is a clear relevance of Plastic Surgery in the setting of general medical care. Even during the pandemic crises a sufficient plastic surgery service is mandatory in a tertiary referral center.


Subject(s)
Coronavirus Infections/epidemiology , Pneumonia, Viral/epidemiology , Surgery, Plastic/statistics & numerical data , Betacoronavirus , COVID-19 , Elective Surgical Procedures/statistics & numerical data , Hospitals, University , Humans , Pandemics , SARS-CoV-2 , Tertiary Care Centers/statistics & numerical data
7.
Unfallchirurg ; 123(12): 961-968, 2020 Dec.
Article in German | MEDLINE | ID: mdl-32385537

ABSTRACT

BACKGROUND: Soft tissue reconstruction in aged patients is challenging. Free tissue transfer can be carried out in healthy patients with a high success rate despite old age. When free tissue transfer is contraindicated in multimorbid patients, local flaps are often chosen, which are associated with a high complication rate. Such salvage interventions must be selected so that an amputation is not disadvantageously influenced by the selection of the donor site or is even impossible. METHODS: The three distally based local flaps the sural artery flap, peroneus brevis muscle flap and perforator-based propeller flaps are discussed with respect to placement of the donor site as well as wound healing disorders. RESULTS: The sural artery flap is disadvantageous as the donor site because the proximal dorsal calf region is affected, which in the case of a below the knee amputation enables soft tissue covering of the stump. CONCLUSION: If a local flap is to be used as a salvage surgery in an attempt to prevent a below the knee amputation in a patient who is not suitable for free tissue transfer, special emphasis must be placed on the donor site of this flap. The proximal dorsal aspects of the distal calf are required for covering a potential stump and should not be violated by harvesting a local flap.


Subject(s)
Perforator Flap , Plastic Surgery Procedures , Soft Tissue Injuries , Amputation, Surgical , Humans , Leg , Soft Tissue Injuries/surgery , Surgical Flaps , Treatment Outcome
8.
JPRAS Open ; 24: 47-55, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32346592

ABSTRACT

BACKGROUND: The soft tissue of the central pretibial area is difficult to reconstruct often requiring free tissue transfer. Especially medically compromised patients are not ideal candidates for free tissue transfer and may benefit from expeditiously harvested local flaps with limited donor site morbidity. As muscle flaps are rare, pedicled flaps based on lateral perforators represent an alternative as the arc of rotation can often be limited to 90°. MATERIAL AND METHODS: A retrospective analysis of patient data was conducted to identify patients over the age of 60 years with comorbidities that underwent pretibial soft tissue reconstruction with a single-pedicle perforator flap. Patient demographics, size and cause of the defect, flap dimension, arc of rotation and complications were recorded. RESULTS: Five patients with an average age of 71.4 years were included. The arc of rotation was 69°, all flaps healed. There were two recurrences of osteomyelitis. CONCLUSION: Lateral perforators originating from the anterior tibial artery or peroneal artery are adequate source vessels for single pedicled perforator flaps even in medically compromised patients. A perforator located proximal to the defect allows limiting the arc of rotation to less than 90°, which increases the safety of the flap. Patients benefit from a simple procedure without a microvascular anastomosis and a donor site confined to one extremity.

9.
J Hand Surg Eur Vol ; 45(2): 131-135, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31739733

ABSTRACT

The Stener-type lesion of the radial collateral ligament is rare. The insertion of the abductor pollicis brevis is believed to preclude its occurrence. The aim of this study was to determine whether this lesion can be induced mechanically. Four specimens were tested in neutral rotation and 20° of supination, in 45° and 30° of flexion, and in the neutral position. The angle of ulnar adduction to form a Stener-type lesion was measured. The lesion occurred only in 45° flexion in all specimens. A lesser angle of flexion decreased the rate of ligament displacement. In the neutral position no ligament displacement was found. A Stener-type lesion of the radial collateral ligament can occur in ulnar adduction and flexion of the metacarpophalangeal joint. Supination of the joint increases the likelihood of ligament displacement. As distal ruptures of the radial collateral ligament are uncommon, a high index of suspicion is required for diagnosis.


Subject(s)
Collateral Ligaments , Thumb , Collateral Ligaments/diagnostic imaging , Humans , Joint Capsule , Metacarpophalangeal Joint/diagnostic imaging , Range of Motion, Articular , Thumb/diagnostic imaging
10.
Plast Reconstr Surg Glob Open ; 7(9): e2396, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31942377

ABSTRACT

Pedicled perforator flaps have expanded reconstructive options in extremity reconstruction. Despite preoperative mapping, intraoperative findings may require microvascular tissue transfer when no adequate perforators can be found. The free peroneal artery perforator flap may serve as a reliable back-up plan in small defects. METHODS: In 16 patients with small soft tissue defects on the upper and lower extremities, perforator-based propeller flaps were planned. The handheld Doppler device was used to localize potential perforators for a propeller flap in close proximity to the defect. Perforators of the proximal peroneal artery were also marked to allow conversion to microvascular tissue transfer. RESULTS: In 6 cases, no adequate perforators were found intraoperatively. In 4 patients, the peroneal artery perforator flap was harvested and transferred. The pedicle length did not exceed 4 cm. No flap loss occurred. CONCLUSIONS: When no adequate perforator capable of nourishing a propeller flap can be found intraoperatively, the free peroneal artery flap is a good option to reconstruct small soft tissue defects in the distal extremities. The short vascular pedicle is less ideal in cases with a large zone of injury requiring a more distant site of anastomosis or when recipient vessels are located in deeper tissue planes.

11.
Plast Reconstr Surg Glob Open ; 7(9): e2462, 2019 Sep.
Article in English | MEDLINE | ID: mdl-31942410

ABSTRACT

Although indocyanine-green fluorescence angiography (ICG-FA) has been established as a useful tool to assess perfusion in free tissue transfer, only few studies have applied this modality to pedicled perforator flaps. As both volume and reach of pedicled perforator flaps are limited and tip necrosis often equals complete flap failure, ICG-FA may help to detect hypoperfusion in pedicled flaps. METHODS: In 5 patients, soft tissue reconstruction was achieved with pedicled perforator flaps. ICG-FA was utilized intraoperatively to visualize flap perfusion. RESULTS: Three pedicled anterolateral thigh flap flaps and 2 propeller flaps were transferred. ICG-FA detected hypoperfusion in 2 flaps. No flap loss occurred; in 2 cases, prolonged wound healing was encountered. CONCLUSIONS: ICG-FA confirmed clinical findings and reliably detected tissue areas with hypoperfusion. A clear cut-off point between nonvital tissue and such that stabilized in the following clinical course could not be found. ICG-FA is a promising technology which could also be used in pedicled perforator flaps.

12.
J Hand Surg Am ; 44(3): 249.e1-249.e5, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30033346

ABSTRACT

PURPOSE: Fascia flaps are a preferred method to reconstruct the soft tissue envelope of the hand when a thin and pliable flap is required to cover exposed tendons. The aim of this study was to report on our experience with the fascia-only reversed posterior interosseous artery flap. Contrary to commonly used fascia flaps, this flap does not require free tissue transfer. METHODS: In this retrospective review, 5 patients were identified, each of whom underwent soft tissue reconstruction with a reversed posterior interosseous artery fascia flap. The operative technique is similar to the harvest of a fasciocutaneous flap except that only the fascia is harvested through a straight incision. RESULTS: No flap loss occurred. In 2 patients a distal wound dehiscence occurred, which healed by secondary intention. No venous congestion or iatrogenic lesion of the motor nerves to the extensor muscles was encountered. CONCLUSIONS: The fascia-only reverse posterior interosseous artery flap represents a locally available, pedicled option. With regard to the quality of the transferred tissue, this flap is comparable to the temporalis fascia flap. Major advantages are that the donor site is confined to the ipsilateral extremity and microsurgery is not required. Contrary to the fasciocutaneous version, no skin graft has to be applied to the donor site, which improves cosmesis. We consider this flap a worthwhile alternative to other fascia flaps. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic V.


Subject(s)
Fascia/transplantation , Hand Injuries/surgery , Soft Tissue Injuries/surgery , Surgical Flaps/blood supply , Adult , Aged , Humans , Male , Middle Aged , Retrospective Studies
13.
Plast Reconstr Surg Glob Open ; 6(4): e1760, 2018 Apr.
Article in English | MEDLINE | ID: mdl-29876190

ABSTRACT

BACKGROUND: Reverse oblique distal radio-ulnar joint (DRUJ) configuration is assumed to show inferior postoperative results in ulnar-shortening osteotomy due to osteoarthritis, as the joint force pressure in the DRUJ may be increased. An evaluation and comparison of the postoperative functional results with regard to clinical and radiographic signs of arthritis among different DRUJ configurations was carried out retrospectively. METHODS: Sixty-two patients after ulnar shortening osteotomy were included. The minimum follow-up was 5 years. Preoperative x-rays were assessed for the DRUJ configuration according to the Tolat classification, whereas postoperative radiographs were evaluated with regard to signs of osteoarthritis using the Kallgren-Lawrence-Score. Functional results were evaluated using the disabilities of the arm, shoulder and hand (DASH) and Mayo Wrist Score and measuring range of motion and grip strength. RESULTS: Significantly better functional results were found in patients with parallel configuration of the DRUJ (Tolat type 1 configuration) with regard to DASH score, grip strength, and supination compared with nonparallel configurations. In the Tolat type 1, configurated DRUJ mean DASH score was 9 compared with 18 in the Tolat type 2 and 3 groups. Apart from supination, no differences were observed in range of motion among groups. CONCLUSION: Although long-term postoperative range of motion failed to display statistically significant differences between DRUJ configurations except for supination, better results regarding grip strength and DASH scores were seen in a parallel-aligned DRUJ configuration. Although onset of osteoarthritis does not seem to become apparent within the observation period, nonparallel aligned configuration predisposes to inferior results.

14.
Plast Reconstr Surg Glob Open ; 5(10): e1544, 2017 Oct.
Article in English | MEDLINE | ID: mdl-29184750

ABSTRACT

BACKGROUND: Propeller flaps require torsion of the vascular pedicle of up to 180 degrees. Contrary to free flaps, where the relevance of an intact vascular pedicle has been documented, little is known regarding twisted pedicles of propeller flaps. As secondary surgeries requiring undermining of the flap are common in the extremities, knowledge regarding the necessity to protect the pedicle is relevant. The aim of this study was a long-term evaluation of the patency of vascular pedicle of propeller flaps. METHODS: In a retrospective clinical study, 22 patients who underwent soft-tissue reconstruction with a propeller flap were evaluated after 43 months. A Doppler probe was used to locate and evaluate the patency of the vascular pedicle of the flap. RESULTS: The flaps were used in the lower extremity in 19 cases, on the trunk in 3 cases. All flaps had healed. In all patients, an intact vascular pedicle could be found. Flap size, source vessel, or infection could therefore not be linked to an increased risk of pedicle loss. CONCLUSIONS: The vascular pedicle of propeller flaps remains patent in the long term. This allows reelevation and undermining of the flap. We therefore recommend protecting the pedicle in all secondary cases to prevent later flap loss.

15.
Plast Reconstr Surg Glob Open ; 5(7): e1397, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28831343

ABSTRACT

Bone-ligament-bone grafts for reconstruction of the scapholunate ligament are a valuable tool to prevent disease progression to carpal collapse. Locally available grafts do not require an additional donor site. The first extensor compartment was evaluated biomechanically regarding its possible use as an autograft. METHODS: Twelve native fresh-frozen, human cadaver specimens were tested by applying axial tension in a Zwick Roell machine. Load to failure, transplant elongation, and bony avulsion were recorded. The load to failure was quantitated in newtons (N) and the displacement in length (millimeters). Parameters were set at distinct points as start of tension, 1 mm stretch and 1.5 mm dissociation, failure and complete tear, and were evaluated under magnified visual control. Although actual failure occurred at higher tension, functional failure was defined at a stretch of 1.5 mm. RESULTS: Mean load at 1 mm elongation was 44.1 ± 28 N and at 1.5 mm elongation 57.5 ± 42 N. Failure occurred at 111 ± 83.1 N. No avulsion of the bony insertion was observed. Half the transplants failed in the central part of the ligament, while the rest failed near the insertion but not at the insertion itself. Analysis of tension strength displayed a wide range from 3.8 to 83.7 N/mm at a mean of 33.4 ± 28.4 N/mm. CONCLUSIONS: The biomechanical tensile properties of the first dorsal extensor compartment are similar to those of the dorsal part of the scapholunate ligament. A transplant with a larger bone stock and a longer ligament may display an advantage, as insertion is possible in the dorsal, easily accessible part of the carpal bones rather than in the arête-like region adjacent to the insertion of the scapholunate ligament. In this study, 1.5 mm lengthening of the bone-ligament-bone transplant was defined as clinical failure, as such elongation will cause severe gapping and is considered as failure of the transplant.

16.
Plast Reconstr Surg Glob Open ; 5(6): e1361, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28740775

ABSTRACT

BACKGROUND: The integrity of the flexor tendon pulley apparatus is crucial for unimpaired function of the digits. Although secondary reconstruction is an established procedure in multi-pulley injuries, acute reconstruction of isolated, closed pulley ruptures is a rare occurrence. There are 3 factors influencing the functional outcome of a reconstruction: gapping distance between tendon and bone (E-space), bulkiness of the reconstruction, and stability. As direct repair is rarely done, grafts are used to reinforce the pulley. An advantage of the first extensor retinaculum graft is the synovial coating providing the possibility to be used both as a direct graft with synovial coating or as an onlay graft after removal of the synovia when the native synovial layer is present. METHODS: A graft from the first dorsal extensor compartment is used as an onlay graft to reinforce the sutured A4 pulley. This technique allows reconstruction of the original dimensions of the pulley system while stability is ensured by anchoring the onlay graft to the bony insertions of the pulley. RESULTS: Anatomical reconstruction can be achieved with this method. The measured E-space remained 0 mm throughout the recovery, while the graft incorporated as a slim reinforcement of the pulley, displaying no bulkiness. CONCLUSIONS: The ideal reconstruction should provide synovial coating and sufficient strength with minimal bulk. Early reconstruction using an onlay graft offers these options. The native synovial lining is preserved and the graft is used to reinforce the pulley.

17.
Plast Reconstr Surg Glob Open ; 5(4): e1313, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28507872

ABSTRACT

Multiple-level amputations of the upper extremity represent a surgical challenge generally only attempted in young patients. This case demonstrates a successful replantation in an elderly woman. The postoperative course was complicated by disseminated intravascular coagulopathy most likely due to inadequate resuscitation. Hand trauma is often underestimated in its general severity. Upper extremity amputations need to be handled similar to polytraumatized patients.

18.
J Orthop Sci ; 22(3): 434-437, 2017 May.
Article in English | MEDLINE | ID: mdl-28117126

ABSTRACT

BACKGROUND: Intraarticular fractures of the distal radius present a challenging problem for surgeons. While preoperative CT scans are considered helpful to understand the type of fracture and to choose an adequate approach, the role of postoperative CT scans is not yet clearly defined. The aim of this study was to analyze indications for postoperative CT scans and to evaluate its potential therapeutic consequence in regard to detection of complications and its influence on revision rates in intraarticular fractures. These findings were used to establish an algorithm to help identifying patients that benefit from a postoperative CT scan. PATIENTS AND METHODS: Ninety-two patients with intraarticular fractures were included. AO type C fractures were seen in about 90% of patients, with type C3 being present in 55% of the patients. According to Frykman's classification type 7 and 8 fractures were found in 93%. Data was analyzed in regard to radiographic results, complications and indication for a postoperative CT scan. RESULTS: Six patients underwent revision surgery. When analyzing data in regard to correlation of radiographs and CT Scans a statistically significant correlation was found. CONCLUSIONS: A high correlation between both imaging techniques can be shown. In inconclusive radiographs, CT scans are recommended to rule out intraarticular screw placement or step offs. Due to the number of patients and the retrospective design, further studies are needed.


Subject(s)
Fracture Fixation, Internal/adverse effects , Intra-Articular Fractures/diagnosis , Postoperative Complications/diagnosis , Radius Fractures/diagnosis , Tomography, X-Ray Computed/methods , Adolescent , Adult , Aged , Aged, 80 and over , Female , Follow-Up Studies , Fracture Fixation, Internal/methods , Humans , Intra-Articular Fractures/surgery , Male , Middle Aged , Postoperative Period , Radius Fractures/surgery , Reoperation , Reproducibility of Results , Retrospective Studies , Time Factors , Wrist Joint/diagnostic imaging , Young Adult
19.
Cytotherapy ; 16(12): 1700-8, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25304663

ABSTRACT

BACKGROUND AIMS: Complex injuries of the upper and lower extremities often result in scarring and subsequent adhesion formation, which may cause severe pain and distinctly reduce range of motion. In revision surgery, replacement of the missing subcutaneous tissue is desirable to prevent new adhesions, to cushion scarred tendons and nerves and to regain tissue elasticity. Therefore, the objective of this study was the in vitro evaluation of cell-seeded collagen matrices to serve as the basis for the reconstruction of the subcutaneous adipose tissue layer. METHODS: Five commercially available acellular dermal collagen matrices were seeded with human adipose-derived stromal cells (hASC). Size and shape stability of cell-matrix constructs were assessed and cell adhesion onto the matrix surface was evaluated histologically. Adipogenic differentiation of hASC on matrices was evaluated by means of histological staining, triglyceride quantification, and quantitative real-time polymerase chain reaction gene expression analysis. RESULTS: The collagen matrix Permacol was the only cell-seeded material that exhibited excellent size and shape stability. For Permacol and Strattice, successful seeding with continuous cell layers on top of the matrices was observed. For both matrices, histological staining, triglyceride quantification and messenger RNA expression of adipogenic transcription factors indicated substantial adipogenic differentiation of hASC after long-term induction as well as after short-term induction of only 4 days. CONCLUSIONS: Of all matrices investigated, only Permacol exhibited adequate handling stability and the development of a thin adipose tissue layer on top of the matrix. Thus, this matrix appears promising to be used in the development of a subcutaneous cushioning layer after complex injuries involving large scar formation.


Subject(s)
Collagen/chemistry , Extracellular Matrix/chemistry , Mesenchymal Stem Cells/metabolism , Subcutaneous Fat/metabolism , Adult , Cell Culture Techniques , Cells, Cultured , Female , Gene Expression Regulation , Humans , Male , Mesenchymal Stem Cells/cytology , Middle Aged , Subcutaneous Fat/cytology
20.
J Orthop Surg Res ; 9: 72, 2014 Aug 21.
Article in English | MEDLINE | ID: mdl-25205062

ABSTRACT

BACKGROUND: Barbed suture material offers the possibility of knotless flexor tendon repair, as suggested in an increasing number of biomechanical studies. There are currently two different absorbable barbed suture products available, V-Loc and Stratafix, and both have not been compared to each other with regard to flexor tendon repair. The purpose of this study was to evaluate both suture materials for primary stability under static and cyclic loading in a biomechanical ex vivo model. METHODS: Forty fresh porcine flexor digitorum profundus tendons were randomized in two groups. A four-strand modified Kessler suture technique was used to repair the tendon either with a 3-0 V-Loc or 3-0 Stratafix without a knot. Parameters of interest were mode of failure, 2-mm gap formation force, displacement, stiffness and maximum load under static and cyclic testing. RESULTS: The maximum load was 42.3 ± 7.2 for the Stratafix group and 50.7 ± 8.8 N for the V-Loc group. Thus, the ultimate tensile strength was significantly higher for V-Loc (p < 0.05). The 2-mm gap occurred at 24.8 ± 2.04 N in the Stratafix group in comparison to 26.5 ± 2.12 N in the V-Loc group (n.s.). Displacement was 2.65 ± 0.56 mm in the V-Loc group and 2.71 ± 0.59 mm in the Stratafix group (n.s.). Stiffness was 4.24 ± 0.68 (N/mm) in the V-Loc group and 3.85 ± 0.55 (N/mm) the Stratafix group (n.s.). Those measured differences were not significant. CONCLUSION: V-Loc demonstrates a higher maximum load in tendon reconstruction. The differences in 2-mm gap formation force, displacement and stiffness were not significant. Hereby, the V-Loc™ has an advantage when used as unidirectional barbed suture for knotless flexor tendon repair.


Subject(s)
Sutures , Tendons/surgery , Biomechanical Phenomena , Equipment Design , Humans
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