Intercalary allograft reconstruction following femoral tumour resection: mid- and long-term results and benefits of adding a vascularised fibula autograft

First-ever ankle arthrodesis with the Capanna technique in an infected open fracture

Although bone transport by means of distraction osteogenesis has become the standard of care for massive segmental bone defects, the technique faces limitations such as the lengthy period of time during which patients must wear an external fixator. Thus, other techniques may be more appropriate in certain circumstances. Capanna developed a combination of vascularized fibular grafts and strut allografts in a way that the strut allograft provides with significant initial mechanical stability, which facilitates incorporation of a vascularized fibular graft and promotes long-term survival of the reconstruction. The case presented in this report is the first in the medical literature where a circular external fixator is used as a stabilization method in a patient with a structural bone deficiency treated by means of the Capanna technique. It is also one of the few reported cases where the underlying condition does not originate in a tumor and where the joint is involved.

Management of segmental defects post open distal femur fracture using a titanium cage combined with the Masquelet technique A single-centre report of 23 cases

INTRODUCTION

The segmental bone defects post open distal femur fracture presents a reconstructive challenge, which often requires extreme solutions. The present study reviewed a new treatment strategy which used a cylindrical titanium mesh cage as an adjunct to the Masquelet technique.

METHODS

We retrospectively reviewed a consecutive series of 23 patients treated for segmental bone defects post open distal femur fracture using a titanium mesh cage combined with the Masquelet technique under a 2-staged protocol in our institution from 2017 to 2021. The study group consisted of 13 men and 10 women with an average age of 44.1 years. The surgical debridement was performed with antibiotic polymethylmethacrylate (PMMA) cement spacer implanted into the bone defect combined with cement-wrapped plate stabilization, or antibiotic beads with vacuum sealing drainage (VSD) to cover the wound. The second stage of the Masquelet technique for bone defect repair began at least 4-6 weeks after the first stage, once all signs of possible infection were eliminated. After the cement spacer was removed, the definitive reconstruction was completed with exchange to a cylindrical titanium mesh cage filled with cancellous autograft within the induced membrane. The bone defect with cage was stabilized with a distal femoral Less Invasive Stabilization System (LISS). The radiological and clinical records of the enrolled patients were retrospectively analyzed.

RESULTS

The mean follow-up was 38.6 months. The average number of operations before the second stage was 1.3. The mean interval between the two stages was 12.7 weeks. The average length of the defect measured 8.3 cm (ranging from 6.1 to 12.4 cm). All the defects filled with autograft within the cage achieved bony union, with a mean healing time of 8.4 months. At the latest follow-up, the mean knee extension measured 6.2° (ranging from 0° to 20°), and the mean flexion measured 101.8° (ranging from 60° to 120°). Complications included two instances of superficial stitch abscess, which eventually healed.

CONCLUSIONS

The use of a titanium cage implanted into an induced membrane in a 2-staged Masquelet protocol could achieve satisfactory clinical outcomes in cases of segmental defects following open distal femur fractures.

Treatment of a case of septic tibial nonunion by the Capanna technique

This report presents the case of a 25-year-old male with an infected tibial diaphyseal nonunion caused by a bone transport procedure carried out to treat an open fracture the patient had sustained 10 years before referral to our hospital. After an initial radical debridement, a bone defect was created, which was subsequently obliterated by placement of an antibiotic-impregnated cement spacer and Stimulan beads and covered by an anterolateral thigh flap. As the patient refused to wear an external fixator and his osseous biology was not amenable to a Masquelet procedure, a decision was made to apply the Capanna technique as soon as the infection healed. The second debridement resulted in a 12-cm-long bone defect that was filled with a tibial allograft and a vascularized fibular graft. At six months, the patient had regained full knee function and was able to bear his full weight, without pain or the need of support equipment. At one year, the bone had healed completely, the infection had subsided and the patient was able to resume his everyday activities. Although the Capanna technique was initially developed to reinforce reconstructions at risk of fracture or nonunion as a result of chemotherapy, its use in post-traumatic cases has been shown to be successful in a selected group of patents. Our study demonstrated that increasing the stability of a reconstruction with an allograft can accelerate the time to heal, and that using a vascularized fibular graft can enhance incorporation of the whole construct. It can be concluded that the Capanna technique is a valid treatment option for managing infected segmental bone defects in selected patients.

Graft Survivals after Reconstruction Using Tumor-Bearing Frozen Bone in the Extremities

Tumor-bearing frozen autografts have been widely used for reconstruction of bone defects caused by tumor resection. However, some patients undergo removal of the grafted bone due to surgical site infection, tumor recurrence, or fractures of the grafted bone. In this retrospective cohort study, predictive factors for graft survival were investigated in 123 patients who underwent reconstructions using a tumor-bearing frozen autograft after bone tumor resection of the extremities. To determine the independent predictors of graft survival, the association between various parameters and graft survival was investigated. The graft survival rates were 83.2% at 5 years and 70.2% at 10 years. Among the 123 frozen autografts, 25 (20.3%) were removed because of complications. In univariate analyses, male sex, BMI of ≥23.6, tibia, and chemotherapy were significantly associated with poor graft survival, whereas the pedicle/hemicortical freezing procedure was significantly associated with better graft survival. Multivariate analysis using the Cox proportional hazards regression model revealed that BMI of ≥23.6 (HR, 3.4; p = 0.005), tibia (HR, 2.3; p = 0.047), and freezing procedure (HR, 0.3; p = 0.016) were independently associated with graft survival. Based on the results, pedicle or hemicortical freezing techniques are recommended in cases where these techniques can be applied.