Osteogenic Capacities of Periost Grafts, Periost Flaps and Prefabricated Periosteal Flaps: Experimental Study

Histological and radiological outcome after horizontal guided bone regeneration with bovine bone mineral alone or in combination with bone in edentulous atrophic maxilla: A randomized controlled trial

OBJECTIVE

To assess the radiological and histological outcome after horizontal guided bone regeneration (GBR) with deproteinized bovine bone mineral (DBBM) alone or in combination with particulate autogenous bone (PAB).

MATERIALS AND METHODS

Eighteen edentulous patients with an alveolar ridge of ≤4 mm were included in this split-mouth randomized controlled trial. Horizontal GBR with a graft composition of 100% DBBM (100:0) on one side and 90% DBBM and 10% PAB (90:10) on the other side were conducted in all patients. Cone beam computed tomography (CBCT) was obtained preoperatively, immediately postoperative, and after 10 months of healing. Width and volumetric changes in the alveolar process were measured on CBCT. Implants were placed after 10 months of graft healing where biopsies were obtained for histomorphometrical evaluation.

RESULTS

The gained widths were 4.9 (±2.4) mm (100:0) and 4.5 (±2.0) mm (90:10) at 3 mm from the top of the crest, and 5.6 (±1.3) mm (100:0) and 4.6 (±2.1) mm (90:10) at 6 mm from the top of the crest. The mean volumetric reductions were 32.8% (±23.8) (100:0) and 38.2% (±23.2) (90:10). Histomorphometry revealed that mean percentages of bone were 50.8% (±10.7) (100:0) and 46.4% (±11.3) (90:10), DBBM were 31.6% (±12.6) (100:0) and 35.4% (±14.8) (90:10), and non-mineralized tissue were 17.6% (±11.7; 100:0) and 18.2% (±18.2) (90:10). No significant differences were evident between in any evaluated parameters.

CONCLUSIONS

There were no additional effects of adding PAB to DBBM regarding bone formation, width changes, or volumetric changes after 10 months of graft healing.

Anatomical Study of the Application of a Galeo-Pericranial Flap in Oral Cavity Defects Reconstruction

Oral cavity defects occur after resection of lesions limited to the mucosa, alveolar gum, or minimally affecting the bone. Aiming at esthetical and functional improvements of intraoral reconstruction, the possibility of harvesting a new galeo-pericranial free flap was explored. The objective of this study was to assess the technical feasibility of flap harvesting through anatomical dissections and surgical procedure simulations. Ten head and neck specimens were dissected to simulate the surgical technique and evaluate the vascular calibers of temporal and cervical vessels. The procedure was therefore reproduced on a revascularized and ventilated donor cadaver. Anatomical dissections demonstrated that the mean cervical vascular calibers are compatible with superficial temporal ones, proving to be adequate for anastomosis. Perforating branches of the superficial temporal vascularization nourishing the pericranium were identified in all specimens. In conclusion, blood flow presence was recorded after anastomosing superficial temporal and facial vessels in the revascularized donor cadaver, demonstrating both this procedure's technical feasibility and the potential revascularization of the flap and therefore encouraging its potential in vivo application.

Combined Free Flaps for Optimal Orthoplastic Lower Limb Reconstruction: A Retrospective Series

Background and Objectives: Open fracture of the lower limb can lead to substantial bone and soft tissue damage, resulting in a challenging reconstructive scenarios, especially in presence of bone or periosteal loss, with a relevant risk of non-union. This work analyzes outcomes of using a double approach for orthoplastic reconstruction, adopting the free medial condyle flap to solve the bone defects, associated to a second free flap for specific soft tissue coverage. Indications, outcomes and reconstructive rationales are discussed. Materials and Methods: A retrospective investigation was performed on patients who underwent complex two-flap microsurgical reconstruction from January 2018 to January 2022. Inclusion criteria in this study were the use of a free femoral condyle periostal/bone flap together with a second skin-only flap. Only distal third lower limb reconstructions were included in order to help equalize our findings. Out of the total number of patients, only patients with complete pre- and post-operative follow-up (minimum 6 months) data were included in the study. Results: Seven patients were included in the study, with a total of 14 free flaps. The average age was 49. Among comorbidities, four patients were smokers and none suffered from diabetes. Etiology of the defect was acute trauma in four cases and septic non-union in three cases. No major complications occurred, and all flaps healed uneventfully with complete bone union. Conclusions: Combining a bone periosteal FMC to a second skin free flap for tailored defect coverage allowed achievement of bone union in all patients, despite the lack of initial bone vascularization or chronic infection. FMC is confirmed to be a versatile flap for small-to-medium bone defects, especially considering its use as a periosteal-only flap, with minimal donor site morbidity. Choosing a second flap for coverage allows for a higher inset freedom and tailored reconstruction, finally enhancing orthoplastic success.

Hard and soft tissue augmentation of vertical ridge defects with the “hard top double membrane technique”: introduction of a new technique and a case report

<abstract> <p>Vertical ridge defects (VRD) of the jaws often require both bone and keratinized mucosa (KM) reconstruction. A new staged procedure is proposed to restore both hard and soft tissues in the VRD through a case report. A patient required the lower right second premolar and first molar rehabilitation. The first surgery aimed to restore the bone architecture through the use of a titanium reinforced dense-PTFE (TR-dPTFE) membrane, positioned and stabilized on top of tenting screws. This membrane didn't cover the whole defect, it just created an hard top that avoided the collapse of a collagen membrane that was placed over it. This resorbable membrane was stabilized with tacks and covered the whole defect, protecting a mixture of autogenous bone and porcine xenograft both lingually and buccally. The second surgery was performed after a 5 month healing time either to remove the tenting screws and the TR-dPTFE membrane, and to augment KM with a gingival graft harvested from the palate. Both regenerated hard and soft tissues were left to mature for 7 months before the third surgery. In this last stage implants insertion and healing abutments application were carried out in a straightforward way, since bone and KM had been previously restored. Two bone samples, harvested for histologic evaluation, stated a great amount of new bone formation. This new approach allowed inserting implants in matured and stable regenerated bone and augmented KM, avoiding the hard and soft tissue loss around implant neck that can affect the VRD treatments during healing.</p> </abstract>

Fibula Free Flap Reconstruction of the Maxilla Leading to Extracapsular Ankylosis of the Mandible

After en bloc resection of the maxilla or mandible, surgeons may choose to replace the missing bone and soft tissue with a fibula free flap (FFF). One of the complications that may arise during the healing of an FFF is heterotopic ossification along the free flap pedicle. Heterotopic ossification is most often noted incidentally on postoperative radiographs and rarely creates a functional deficit. Subperiosteal dissection of the pedicle from the bone during the harvest of the FFF is believed to be the main contributing factor that leads to this formation of bone along the flap soft tissue. Pain or limitation of movement of the jaws, depending on where heterotopic bone forms are related functional issues. Changes in facial appearance due to expansion related to this phenomenon of bone deposition may also occur. This paper presents a patient that developed a functional deficit secondary to heterotopic ossification of an FFF that required surgical intervention. The goal of our surgery is to maintain the blood supply to a vascularized flap while removing the heterotopic bone. We will present the unique aspects of planning this challenging surgery: CASE: A 40-year-old man with a history of right posterior maxillary ameloblastoma underwent a hemi-maxillectomy with FFF reconstruction. The patient developed extracapsular heterotopic bone ankylosis beginning 2 months postoperatively developing severe trismus and required surgical intervention. Radiographic imaging revealed extensive heterotopic ossification of the vascular pedicle that extended from the most proximal positioned end of the fibula to the inferior lateral border of the mandible. A radiographic computed tomography with contrast imaging revealed an intact vascular pedicle with surrounding heterotopic bone. Virtual planning and stereolithic modeling were utilized to plan the heterotopic bone removal. In the operating room, we removed the heterotopic bone in small segments according to the virtual plan to avoid injuring the vascular pedicle. A coronoidectomy was also performed to help gain more range of motion. An adipofascial flap using the buccal fat pad was raised into the area of defect to prevent future recurrence. The patient was put on a strict physical therapy regimen to help regain his range of motion. CONCLUSION: Heterotopic ossifications along free flap pedicles are a known complication of the FFF. A conservative management approach should be used since most postoperative patients will be asymptomatic and findings are incidental on postoperative imaging. Surgery should be reserved for symptomatic patients. Heterotopic ossification needs to be considered as a differential in a microvascular reconstruction postoperative patient when the patient presents with a slow onset of facial swelling, neck mass, or trismus. Virtual planning is an essential tool in the surgeon's planning armamentarium dependent on the timing of the procedure so that the vascular integrity of the flap can be protected after the initial anastomosis.

Periosteal medial femoral condyle free flap for metacarpal nonunion

Background

Metacarpal nonunion is a rare condition. The osteogenic capacity of periosteal free flap was investigated in five patients with metacarpal nonunion and impaired bone vascularization.

Patients and methods

Surgery was performed between 64 and 499 days after the initial bone osteosynthesis. The average age was 27.6 (range 16–32) years. Nonunion was caused by excessive periosteal removal in two patients, extensive open trauma in three. Four nonunions were diaphyseal, one metaphyseal. A periosteal medial femoral condyle free flap was raised on the descending genicular artery for four patients, the superomedial genicular artery for one. After osteosynthesis with a plate, the flap was wrapped around the metacarpal, overlapping the bone proximally and distally. The recipient vessel were the dorsal branch of the radial artery and a vena comitans in the anatomical snuffbox in four patients, at the base of the first webspace in one.

Results

The flap size ranged from 5 × 3.5 cm to 8 × 4 cm. No postoperative complication occurred. Radiological bone union was achieved 3 to 8 months after surgery. One patient had a full range of motion, one a slight extension lag of the proximal interphalangeal joint, two moderate joint stiffness of the proximal interphalangeal or metacarpophalangeal joint (one requiring plate removal and extensor tenolysis), one severe stiffness that allowed using a hook grip which was the aim of the surgery.

Conclusion

In case of metacarpal nonunion with impaired bone vascularization, the periosteal medial femoral condyle free flap provides an effective and biomimetic approach to bone healing.

Heterotopic Ossification of the Vascular Pedicle after Maxillofacial Reconstructive Surgery Using Fibular Free Flap: Introducing New Classification and Retrospective Analysis

Heterotopic ossification (HO) is one of the described phenomena after maxillofacial reconstructive surgery using fibular free flap (FFF) at the reception-site. The aim of this study was to determine the radiological incidence and form of HO along the fibular vascular pedicle as well as the rate of clinical symptoms if present. CT-scans of 102 patients who underwent jaw reconstructive surgery by using FFF from January 2005 to December 2019 were evaluated concerning the presence of HO. Subsequently, the patient files were evaluated to identify the cases with clinical signs and complications related to the presence of HO. A radiological classification of four different HO types was developed. Out of 102 patients, 29 (28.43%) presented radiological findings of HO. Clinical symptoms were recorded in 10 cases (9.8%) (dysphagia (n = 5), trismus (n = 3), bony masses (n = 2)) and from these only five (4.9%) needed surgical removal of calcified structures. HO occurs significantly in younger patients (mean 52.3 year). In maxillary reconstructions, HO was radiologically visible six months earlier than after mandibular reconstruction. Furthermore, HO is observed after every third maxilla and every fourth mandible reconstruction. This study developed for the first time a classification of four distinct HO patterns. HO types 1 and 2 were mostly observed after mandible reconstruction and type 4 predominantly after maxilla reconstruction.

The periosteal-cutaneous chimeric medial femoral condyle free flap for subtotal ear reconstruction: A case report

When costal graft is contraindicated or refused by the patient, autologous total/subtotal auricular reconstruction represent a real challenge as limited surgical options has been described. Aim of present report is to offer a novel possible autologous reconstruction of the ear frame using a chimeric free medial femoral condyle (MFC) flap. We present a case of a 29 years old patient who had total loss of the upper 2/3 of the right ear after bombing in Somalia and secondary infected condritis (considered a relative contraindication for costal cartilage graft). The MFC flap was harvested with a chimeric skin paddle (7 × 5 cm), a thin sheet of femoral cortex (6.5 × 8 cm) was used as basal ear frame, while part of the contralateral concha was trimmed as support for the helix, with the periosteal component of the flap wrapping around the whole framework. The chimeric skin paddle assured the retroauricular skin coverage, while the anterior part of the construct was covered by a thinned dermal flap. Postoperative course was uneventful. A defatting procedure of the posterior skin paddle was performed at 2 months post-op. At 6 months post-op, the patient was satisfied with the result, could wear glasses and was socially integrated. This new application of the free chimeric MFC flap, despite being not the primary choice for ear reconstruction, guaranteed satisfactory results in terms of ear shape and infection prevention and may be considered when ordinary cartilage rib reconstruction is refused, contraindicated, or failed.

Treatment of mandibular osteoradionecrosis by periosteal free flaps

Mandibular osteoradionecrosis (ORN) is one of the most serious complications of radiotherapy of the head and neck, and is characterised by hypoxia, hypovascularisation, and hypocellularity. Periosteal free flaps have intrinsic osteogenic, and extrinsic neoangiogenic, properties that are related to the periosteum. Our objective was to present our experience with the use of periosteal free flaps in the treatment of ORN (Notani class I or II) that are refractory to conservative management or have a large area of bone (≥2 cm) exposed. We organised a single-centre, retrospective study between 2003 and 2013 and describe the management of 11 patients (4 women and 7 men) who were being treated for refractory mandibular ORN. Thirteen periosteal free flaps were used: inner femoral condylar periosteum (n = 4), iliac crest (n = 1), external brachial with humeral periosteum (n = 1), and forearm with radial periosteum (n = 7). During follow-up we found three acute complications (haematoma, partial necrosis, and total vascular necrosis) that required immediate construction of a second periosteal free flap. There were also two chronic complications (fistula and post-traumatic fracture). With only one progressive lesion identified, the ORN was stopped in 11/12 patients. Two examples of osteoconduction were identified on postoperative images at six months and two years. Because of its osteoconductive and neoangiogenic capacities, the periosteal free flap seems to offer a real biological dimension to the treatment of ORN, and its efficiency favours its early revascularisation.

Comparison of the wound healing efficacy of polyglycolic acid sheets with fibrin glue and gelatin sponge dressings in a rat cranial periosteal defect model

Oral surgical procedures occasionally require removal of the periosteum due to lesions, and these raw bone surfaces are prone not only to infection but also to scar formation during secondary healing. The objective of this study was to identify successful methods for reconstruction using periosteal defect dressings. We created 1-cm2 defects in the skin and cranial periosteum of 10-week-old male Wistar rats under isoflurane anesthesia. The animals were assigned to three defect treatment groups: (1) polyglycolic acid sheets with fibrin glue dressing (PGA-FG), (2) Spongel® gelatin sponge dressing (GS), and (3) open wound (control). Postoperative wound healing was histologically evaluated at 2, 4, and 6 weeks. The moist conditions maintained by the GS and PGA-FG treatments protected the bone surface from the destructive effects of drying and infection. Complete wound healing was observed in the GS group but not for all animals in the PGA-FG and control groups. Histologically, osteoblast proliferation on bone surfaces and complete epithelialization with adnexa were observed in the GS group at 6 weeks after surgery. In contrast, PGA sheets that had not been absorbed inhibited osteoblast proliferation and delayed wound healing in the PGA-FG group. Wound surface dressings maintain a moist environment that promotes wound healing, but PGA materials may not be suitable for cases involving exposed periosteum or bone surfaces due to the observed scar formation and foreign-body reaction.

Biomechanical Stability of Dental Implants in Augmented Maxillary Sites: Results of a Randomized Clinical Study with Four Different Biomaterials and PRF and a Biological View on Guided Bone Regeneration

Introduction. Bone regenerates mainly by periosteal and endosteal humoral and cellular activity, which is given only little concern in surgical techniques and choice of bone grafts for guided bone regeneration. This study investigates on a clinical level the biomechanical stability of augmented sites in maxillary bone when a new class of moldable, self-hardening calcium-phosphate biomaterials (SHB) is used with and without the addition of Platelet Rich Fibrin (aPRF) in the Piezotome-enhanced subperiosteal tunnel-technique (PeSPTT). Material and Methods. 82 patients with horizontal atrophy of anterior maxillary crest were treated with PeSPTT and randomly assigned biphasic (60% HA/40% bTCP) or monophasic (100% bTCP) SHB without or with addition of aPRF. 109 implants were inserted into the augmented sites after 8.3 months and the insertion-torque-value (ITV) measured as clinical expression of the (bio)mechanical stability of the augmented bone and compared to ITVs of a prior study in sinus lifting. Results. Significant better results of (bio)mechanical stability almost by two-fold, expressed by higher ITVs compared to native bone, were achieved with the used biomaterials and more constant results with the addition of aPRF. Conclusion. The use of SHB alone or combined with aPRF seems to be favourable to achieve a superior (bio)mechanical stable restored alveolar bone.

The vascularized periosteum flap as novel tissue engineering model for repair of cartilage defects

Periosteum is a promising tissue engineering scaffold in research of cartilage repair; so far however, periosteum transfers have not been realized successfully because of insufficient nourishment of the graft. In a translational approach we, for the first time, designed a vascularized periosteum flap as ‘independent’ biomaterial with its own blood supply to address this problem and to reconstruct circumscript cartilage defects. In six 3-month-old New Zealand rabbits, a critical size cartilage defect of the medial femur condyle was created and covered by a vascularized periosteum flap pedicled on the saphenous vessels. After 28 days, formation of newly built cartilage was assessed macroscopically, histologically and qualitatively via biomechanical compression testing, as well as on molecular biological level via immunohistochemistry. All wounds healed completely, all joints were stable and had full range of motion. All flaps survived and were perfused through their pulsating pedicles. They showed a stable attachment to the bone, although partially incomplete adherence. Hyaline cartilage with typical columnar cell distribution and positive Collagen II staining was formed in the transferred flaps. Biomechanical testing revealed a significantly higher maximum load than the positive control, but a low elasticity. This study proved that vascularization of the periosteum flap is the essential step for flap survival and enables the flap to transform into cartilage. Reconstruction of circumscript cartilage defects seems to be possible. Although these are the first results out of a pilot project, this technique, we believe, can have a wide range of potential applications and high relevance in the clinical field.

Schneiderian membrane detachment using transcrestal hydrodynamic ultrasonic cavitational sinus lift: a human cadaver head study and histologic analysis

PURPOSE

Recent studies have suggested the osteogenic layer of the periosteum at the base of the sinus membrane to play a key role in bone regeneration after sinus lift procedures. Thus, atraumatic detachment of the sinus membrane with an intact periosteum seems mandatory. The present histologic study of fresh human cadaver heads investigated the detachment behavior and histologic integrity of the detached periosteum after application of the transcrestal hydrodynamic ultrasonic cavitational sinus lift (tHUCSL-INTRALIFT).

MATERIALS AND METHODS

A total of 15 sinuses in 8 fresh human cadaver heads were treated using tHUCSL-INTRALIFT. After surgery, they were checked macroscopically for damage to the sinus membrane and then processed for histologic inspection under light microscopy. A total of 150 histologic specimens, randomly selected from the core surgical sites, were investigated using hematoxylin-eosin (HE), Azan, and trichrome staining.

RESULTS

None of the 150 inspected specimens showed any perforation or dissection of the periosteum from the subepithelial connective tissue and respiratory epithelium and were fully detached from the bony antrum floor. The connecting Sharpey fibers revealed to be cleanly separated from the sinus floor in all specimens.

CONCLUSIONS

The results of the present study suggest tHUCSL-INTRALIFT should be used to perform predictable and safe detachment of the periosteum from the bony sinus floor as a prerequisite for undisturbed and successful physiologic subantral bone regeneration.

Wrapped omentum with periosteum concurrent with adipose derived adult stem cells for bone tissue engineering in dog model

Adipose derived adult stem cells (ASCs) are multipotent cells that are able to differentiate into osteoblasts in presence of certain factors. The histological characteristics of periosteum makes it a specific tissue with a unique capacity to be engineered. Higher flexibility of the greater omentum is useful for reconstructive surgery. These criteria make it suitable for tissue engineering. The present study was designed to evaluate bone tissue engineering with periosteal free graft concurrent with ASCs and pedicle omentum in dog model. Twelve young female indigenous dogs were used in this experiment. In omental group (n = 4), end of omentum was wrapped by periosteum of the radial bone in abdomen of each dog. In omental-autogenously ASCs group (n = 4), 1 ml of ASCs was injected into the wrapped omentum with periosteum while in omental-allogenously ASCs group (n = 4), 1 ml of allogenous ASCs was injected. Lateral view radiographs were taken from the abdominal cavity postoperatively at the 2nd, 4th, 6th and 8th weeks post-surgery. Eight weeks after operation the dogs were re-anesthetized and the wrapped omenum by periosteum in all groups was found and removed for histopathological evaluation. Our results showed that omentum-periosteum, omental-periosteum-autogenous ASCs and omental-periosteum-allogenous ASCs groups demonstrated bone tissue formation in the abdominal cavity in dog model. The radiological, macroscopical and histological findings of the present study by the end of 8 weeks post-surgery indicate bone tissue engineering in all three groups in an equal level. The present study has shown that the wrapped omentum with periosteum concurrent with ASCs (autogenous or allogenous ASCs) lead to a favorable bone tissue formation. We suggested that it may be useful when pedicle graft omentum used concurrent with periosteum in the bone defect reconstruction, and this phenomenon should be studied in future.

Vascularized periosteal transfer from the medial femoral condyle: is it compulsory to include the cortical bone?

BACKGROUND

The corticoperiosteal flap from the medial femoral condyle has become the workhorse in the management of recalcitrant nonunions with vascularized periosteum. Inclusion of the outer condylar cortex has been advocated to avoid damaging the osteogenic capacity of the periosteum and is at present an ordinary technical step in the procedure.

PATIENTS

A clinical prospective study was undertaken to evaluate the effectiveness of periosteal-only microvascular transfers from the medial femoral condyle associated with bone grafts in the treatment of recalcitrant nonunions. A group of 8 patients with periosteal-only flaps (study group) is compared with a corticoperiosteal control group (13 patients). A statistical analysis is made of the results.

RESULTS

We had 100% union rate in both the study and control groups. Evaluation of early signs of bone healing by two independent evaluators did not found differences between the groups (4.5 months in the study and 4.9 months in the control group).

CONCLUSIONS

Although not statistically significant because of the small sample size, our study might support the idea that both periosteal and corticoperiosteal flaps from the medial femoral condyle are effective, when associated with a bone graft, in the treatment of recalcitrant nonunions with small gaps. A further analysis of the results suggests, albeit no statistical significant, that structural and nonstructural bone grafts are both effective when associated with a vascularized periosteal or corticoperiosteal transfer from the medial femoral condyle.

Biological Principles and Physiology of Bone Regeneration under the Schneiderian Membrane after Sinus Lift Surgery: A Radiological Study in 14 Patients Treated with the Transcrestal Hydrodynamic Ultrasonic Cavitational Sinus Lift (Intralift)

Introduction. Sinus lift procedures are a commonly accepted method of bone augmentation in the lateral maxilla with clinically good results. Nevertheless the role of the Schneiderian membrane in the bone-reformation process is discussed controversially. Aim of this study was to prove the key role of the sinus membrane in bone reformation in vivo. Material and Methods. 14 patients were treated with the minimal invasive tHUCSL-Intralift, and 2 ccm collagenous sponges were inserted subantrally and the calcification process followed up with CBCT scans 4 and 7 months after surgery. Results. An even and circular centripetal calcification under the sinus membrane and the antral floor was detected 4 months after surgery covering 30% of the entire augmentation width/height/depth at each wall. The calcification process was completed in the entire augmentation volume after 7 months. A loss of approximately 13% of absolute augmentation height was detected between the 4th and 7th month. Discussion. The results of this paper prove the key role of the sinus membrane as the main carrier of bone reformation after sinus lift procedures as multiple experimental studies suggested. Thus the importance of minimal invasive and rupture free sinuslift procedures is underlined and does not depend on the type of grafting material used.

Increase in periosteal angiogenesis through heat shock conditioning

Objective

It is widely known that stress conditioning can protect microcirculation and induce the release of vasoactive factors for a period of several hours. Little, however, is known about the long-term effects of stress conditioning on microcirculation, especially on the microcirculation of the periosteum of the calvaria. For this reason, we used intravital fluorescence microscopy to investigate the effects of heat shock priming on the microcirculation of the periosteum over a period of several days.

Methods

Fifty-two Lewis rats were randomized into eight groups. Six groups underwent heat shock priming of the periosteum of the calvaria at 42.5°C, two of them (n = 8) for 15 minutes, two (n = 8) for 25 minutes and two (n = 8) for 35 minutes. After 24 hours, a periosteal chamber was implanted into the heads of the animals of one of each of the two groups mentioned above. Microcirculation and inflammatory responses were studied repeatedly over a period of 14 days using intravital fluorescence microscopy. The expression of heat shock protein (HSP) 70 was examined by immunohistochemistry in three further groups 24 hours after a 15-minute (n = 5), a 25-minute (n = 5) or a 35-minute (n = 5) heat shock treatment. Two groups that did not undergo priming were used as controls. One control group (n = 8) was investigated by intravital microscopy and the other (n = 5) by immunohistochemistry.

Results

During the entire observation period of 14 days, the periosteal chambers revealed physiological microcirculation of the periosteum of the calvaria without perfusion failures. A significant (p < 0.05) and continuous increase in functional capillary density was noted from day 5 to day 14 after 25-minute heat shock priming. Whereas a 15-minute exposure did not lead to an increase in functional capillary density, 35-minute priming caused a significant but reversible perfusion failure in capillaries. Non-perfused capillaries in the 35-minute treatment group were reperfused by day 10. Immunohistochemistry demonstrated an increase in cytoprotective HSP70 expression in the periosteum after a 15-minute and a 35-minute heat shock pretreatment when compared with the control group. The level of HSP70 expression that was measured in the periosteum after 25 minutes of treatment was significantly higher than the levels observed after 15 or 35 minutes of heat shock exposure.

Conclusion

A few days after heat shock priming over an appropriate period of time, a continuous increase in functional capillary density is seen in the periosteum of the calvaria. This increase in perfusion appears to be the result of the induction of angiogenesis.

[Anterior tibial muscle hernia--reconstruction with periosteal patch plasty]

INTRODUCTION

Anterior tibial muscle hernia is the most frequent lower extremities muscle hernia. The aim of this paper was to present a possibility of a new surgical technique for anterior tibial muscle hernia reparation.

CASE REPORT

We presented three cases of anterior tibial muscle hernia in adolescents. The cases were diagnosed clinically and ultrasonographically. In all three cases reconstruction was done with periosteal patch plasty of fascial defect.

CONCLUSIONS

Easy approachable, cheap, autologous material, periost, in the frame of periosteal patch plasty, could be one of the possible solutions in anterior tibial muscle hernia treatment.

Stem cell therapy for cartilage regeneration in osteoarthritis

Enhancing the regeneration potential of hyaline cartilage tissue remains a great challenge. During embryonic development, some of the cells of the inner cell mass will turn into the mesoderm. This will be the founder of the mesenchymal cells in connective tissues of adult life, such as bone, tendon, muscle, and cartilage. Some of these embryonic mesenchymal cells are believed not to differentiate, but reside in each of the tissues. These are now collectively described as adult mesenchymal stem cells, which are thought to be capable of repairing injured tissue. We will briefly summarize the current knowledge about stem cell-related cells in cartilage tissue and carefully discuss the potential of the cell population we described recently as a starting-point for a regenerative therapy for osteoarthritis. We found that repair tissue from human articular cartilage during the late stages of osteoarthritis harbors a unique progenitor cell population, termed chondrogenic progenitor cells (CPC). These exhibit stem cell characteristics combined with a high chondrogenic potential. They offer new insights into the biology of progenitor cells and may be relevant in the development of novel therapeutic approaches for a cell-based therapy for late stages of osteoarthritis.