A review of the Masquelet technique in the treatment of lower limb critical-size bone defects

The need for bone tissue to heal effectively is paramount given its role in the mechanical support of tissues. Bone has a very good natural healing potential in comparison with most other tissue types, largely regenerating to its pre-injury state in the vast majority of cases. Certain factors such as high energy trauma, tumour resection, revision surgery, developmental deformities and infection can lead to the formation of bone defects, where the intrinsic healing potential of bone is diminished owing to bone loss. Various approaches to resolving bone defects exist in current practice, each with their respective benefits and drawbacks. These include bone grafting, free tissue transfer, Ilizarov bone transport and the Masquelet induced membrane technique. This review focuses on evaluating the Masquelet technique, discussing its method and underlying mechanisms, the effectiveness of certain modifications, and its potential future directions.

Surgical method for critical sized cranial defects in rat cranium

Cranial tissue models are a widely used model to show the bone repair and the regeneration ability of candidate biomaterials for tissue engineering purposes. Until now, efficacy studies of different biomaterials for calvarial defect bone regeneration have been reported, generally in small animal models. This paper offers a versatile, reliable, and reproducible surgical method for creating a critical-sized cranial defect in rats including critical steps and tried-and-tested tips. The method proposed here,•Shows a general procedure for in vivo cranial models.•Provide an insight to restore bone tissue repair that may be used in combination with several tissue engineering strategies•Is a crucial technique that may guide in vivo bone tissue engineering.

Utilisation of bioactive glass S53P4 inside an induced membrane for severe bone defect with high risk of infection: a multi-center preliminary experience

BACKGROUND

The induced membrane technique has been developed to address bone defect of critical size from various origins. Despite its exceptional efficacy, several cases underwent a failure, which is regularly associated with a septic problem. The best way to conduct in this situation remains debated.

PURPOSE

To estimate use of bioactive glass S53P4 (BAG-53P4) in induced membrane technique failures or with an anticipated high risk of failure.

MATERIAL AND METHOD

We conducted a retrospective analysis of patients from several medical centers in Europe where BAG-S53P4 has been used inside an induced membrane. The etiology of the defect, the bone fixation used, the delay the bioactive glass was placed, the reason why the bioactive glass was used and the results were reported.

RESULTS

Eight cases were included (3 women and 5 men). Mean age was 43 years (16-82; Standard deviation 23). Mean height was 171 cm (162-184; SD 7), mean weight was 69 kg (60-85; SD 8) and Body Mass Index was 23,39 M/Kg2 (21,9-25,1; SD 1,22). Mean length of defect was 68 mm (40-100mm, SD 23). All patients received BAG-S53P4 granules (BonAlive Biomaterials Ltd, Turku, Finland) to fill the resultant cavity (3 as a stand-alone in the induced membrane and 5 mixed with autograft). Three patients were implanted with BAG-S53P4 during the second stage of a first induced membrane technique because of a high risk of infection (three open fractures); two patients were implanted with BAG-S53P4 during the second stage of a first induced membrane technique because of the great size of the defect (two infectious non-union); two patients were implanted with BAG-S53P4 as a third stage of induced membrane technique, i.e. inside a previously grafted membrane, because of a recurrence of the infection; and one patient was implanted with BAG-S53P4 during the second stage of a second induced membrane technique to avoid a new failure. At a follow-up of 16 months, all healed without any recurrence of the infection.

DISCUSSION

Critical size bone defects caused by an open fracture or an active infection can usually be addressed by the induced membrane technique. However, some cases are at high risk of failure because of the occurrence or recurrence of an infection. In these cases, bioactive glass may help the surgeon to improve the rate of bone union.

CONCLUSION

BAG-S53P4 may be considered as bone graft in an induced membrane technique, especially when there is a high probability of occurrence or recurrence of a bone infection.

Determination of the effective dose of bone marrow mononuclear cell therapy for bone healing in vivo

Introduction

Cell-based therapy by bone marrow mononuclear cells (BMC) in a large-sized bone defect has already shown improved vascularization and new bone formation. First clinical trials are already being conducted. BMC were isolated from bone marrow aspirate and given back to patients in combination with a scaffold within some hours. However, the optimal concentration of BMC has not yet been determined for bone healing. With this study, we want to determine the optimal dosage of the BMC in the bone defect to support bone healing.

Material and methods

Scaffolds with increasing BMC concentrations were inserted into a 5 mm femoral defect, cell concentrations of 2 × 10⁶ BMC/mL, 1 × 10⁷ BMC/mL and 2 × 10⁷ BMC/mL were used. Based on the initial cell number used to colonize the scaffolds, the groups are designated 1 × 10⁶, 5 × 10⁶ and 1 × 10⁷ group. Bone healing was assessed biomechanically, radiologically (µCT), and histologically after 8 weeks healing time.

Results

Improved bone healing parameters were noted in the 1 × 10⁶ and 5 × 10⁶ BMC groups. A significantly higher BMD was observed in the 1 × 10⁶ BMC group compared to the other groups. Histologically, a significantly increased bone growth in the defect area was observed in group 5 × 10⁶ BMC. This finding could be supported radiologically.

Conclusion

It was shown that the effective dose of BMC for bone defect healing ranges from 2 × 10⁶ BMC/mL to 1 × 10⁷ BMC/mL. This concentration range seems to be the therapeutic window for BMC-supported therapy of large bone defects. However, further studies are necessary to clarify the exact BMC-dose dependent mechanisms of bone defect healing and to determine the therapeutically effective range more precisely.

Ilizarov bone transport and treatment of critical-sized tibial bone defects: a narrative review

Background

Critical-sized bone defects of the tibia are complex injuries associated with significant problems that are difficult to treat, and they are associated with a significant burden of disease in clinical practice; however, the treatment of these cases has still been a challenge for orthopedic surgeons. The aim of this review was to evaluate the current available studies reporting on classical Ilizarov methods in the treatment of infected or noninfected critical-sized bone defects of the tibia, and to perform an analysis of treatment period and complications.

Methods

This is a narrative review based on a comprehensive literature search among the studies in Pubmed, Scopus and Web of Science articles. The studies included were written in the English language or translated to English and they were published between 2008 and 2018. They were appraised with narrative data synthesis. The primary outcome measures were the external fixation time (EFT), bone union rate, and bone and functional results. Secondary outcomes were complications including docking site problems and solutions. The heterogeneity of the data in the studies which were taken into consideration allowed a narrative analysis.

Results

Twenty-seven articles with 619 patients were included in this study. These included 6 prospective and 21 retrospective case series. Mean age was 36.1 (range 13–89) years. Of the cases, 88.8% were infected and the remaining 11.2% were noninfected. The external fixation time was 10.75 (range 2.5–23.2) months. The mean bone union rate was 90.2% (range 77–100)%. Radiographic outcome measures were reported in 20 studies. Functional outcome measures were reported in 18 studies. ASAMI (Association for the Study of the Method of Ilizarov) criteria are useful and give reproducible data on patient outcome measurements. Data collected from these studies showed excellent radiological outcomes in 303, good in 143, fair in 31, and poor in 25 patients. Functional outcomes were excellent in 200, good in 167, fair in 58, and poor in 19, where reported. The excellent and good rate in bone results and functional results were 88.8% and 82.6%, respectively. The poor rate in bone results and functional results were 5% and 4.5%. Mean complication rate per patient was 1.22 (range 3–60). The most common complication was pin tract infection (PTI). Its occurrence was 46.6%. Joint stiffness followed PTI with a 25% incidence. The rates of refracture, malunion, infectious recurrence, and amputation, were 4%, 8.4%, 4.58%, and 1%, respectively.

Conclusions

This narrative review shows that the patients with infected or noninfected critical-sized tibial bone defects treated by Ilizarov methods had a low rate of poor bone and functional results. Therefore, Ilizarov methods may be a good choice for the treatment of infected or noninfected tibial bone defects. The small number of cases in some studies, the absence of homogenity between studies and the fact that most data available are derived from retrospective studies are some of the difficulties encountered in the evaluation of evidence.

Level of evidence

V.

Updating control of puberty in male European sea bass: A holistic approach

Puberty is the process by which an immature animal acquires the ability to reproduce for the first time; its onset occurs soon after sexual differentiation and is characterized by the beginning of gametogenesis in both sexes. Here we present new insights on when and how the onset of puberty occurs in male European sea bass, its dependence on reaching a critical size, and how it can be controlled by photoperiod, revealing the existence of a photolabile period with important applications in aquaculture. Regarding size, apparently only European sea bass above a certain size threshold attain the ability to carry out gametogenesis during their first year of life, while their smaller counterparts fail to do so. This could imply that fish need to achieve an optimal threshold of hormone production, particularly from the kisspeptin/Gnrh/Gth systems, in order to initiate and conclude puberty. However, a long-term restricted feeding regime during the second year of life did not prevent the onset of puberty, thus suggesting that the fish are able to maintain the reproductive function, even at the expense of other functions. Finally, the study of daily hormonal rhythms under different photoperiod regimes revealed the equivalence between their core values and those of seasonal rhythms, in such a way that the daily rhythms could be considered as the functional units of the seasonal rhythms.