[Surgery during the SARS-CoV-2 pandemic : Recommendations on operative procedures]. / Chirurgie in der SARS-CoV-2-Pandemie : Empfehlungen zum operativen Vorgehen.

BACKGROUND: In February 2020 Germany was also hit by the SARS-CoV­2 pandemic. Even patients infected by SARS-CoV­2 or COVID-19 may need operative procedures. Currently, no uniform recommendations exist on precautions to be taken when operating on these patients. Furthermore, they may differ from one hospital to another. METHODS: The task force COVID-19 of the emergency, intensive and severely injured section of the German Trauma Society (DGU e. V.) has developed consensus-based recommendations on surgical treatment of patients with SARS-CoV­2 infections. Great importance is placed on the implementation in hospitals at all levels of care. RESULTS: The indications for surgical interventions in patients with COVID-19 infections require an extremely critical evaluation. When indicated these surgical intervention should ideally be performed in a separate operating theater. All personnel involved should wear personal protective equipment with FFP2 masks, face shields and double gloves. The emergency team in the resuscitation bay should generally wear the same personal protective equipment. Special training is mandatory and the exposure of team members should be minimized. CONCLUSION: The recommendations are principally used for all kinds of surgery and comply with the currently available knowledge. Nevertheless, all recommendations represent a compromise between maximum safety of all medical staff and practicability in the routine hospital workflow.

Allograft vasculopathy after allogeneic vascularized knee transplantation.

Composite tissue allotransplantation represents a new discipline in reconstructive surgery. Over the past 10 years, we have performed six human vascularized allogeneic knee transplantations. All of these grafts have been lost within the first 56 months. A histomorphologic assessment of the latest case resulted in the detection of diffuse concentric fibrous intimal thickening and occlusion of graft vessels. Findings are comparable with cardiac allograft vasculopathy. The lack of adequate tools for monitoring graft rejection might have allowed multiple untreated episodes of acute rejection, triggering myointimal proliferation and occlusion of graft vessels. Graft vasculopathy represents an obstacle to long-term vascularized bone and joint allograft survival, and adequate tools for monitoring need to be developed.

Daily subcutaneous Teriparatide injection increased bone mineral density of newly formed bone after tibia distraction osteogenesis, a randomized study.

Long bone defects are often treated by bone segment transport with the Ilizarov method requiring months spent with fixator mounted until bony consolidation of the newly formed bone. Shortening of consolidation would allow earlier fixator removal and earlier return to work. In pre-clinical studies parathyroid hormone, increased bone mineral density and mechanical properties of regenerate bone formed during distraction osteogenesis. Clinical studies showed that Teriparatide accelerated fracture healing in patients with osteoporotic fracture of the pelvis, hip, wrist and shoulder. We hypothesized that rhPTH(1-34) (Teriparatide) administered to patients who had undergone distraction osteogenesis, would increase mineralization of the regenerate formed during the consolidation phase. Sixteen patients with tibial defects after infection, underwent bone segment transport and at the time of docking the transport segment, were randomized to 8 weeks treatment with daily subcutaneous 0.20-µg Teriparatide injection followed by 8 weeks with no treatment, or to 8 weeks with no treatment followed by 8 weeks with daily subcutaneous 0.20 µg Teriparatide injection. Bone mineral density (BMD) of the regenerate was measured at the time of docking, 8 weeks after docking and 16 weeks after docking with DEXA. Functional evaluation was performed after one year. The design was a cross-over study. Overall BMD increased 0.14 g/cm2 in 8 weeks without treatment and 0.33 g/cm2 under Teriparatide treatment. After adjustment for a potential phase difference, 8 weeks of Teriparatide treatment led to an additional 0.19 g/cm2 BMD increase (95%-CI:[0.11,0.28], p < 0.001). The ratio of the BMD increase between the two treatments was 0.33/0.14 = 2.43 (CI: [1.21,3.65]). Teriparatide treatment during the consolidation phase of distraction osteogenesis doubled the mineralization rate of the regenerate when compared to no treatment.

Outcome of allogeneic vascularized knee transplants.

Transplantation of vascularized knee joints is a novel approach in Composite Tissue Allotransplantation (CTA). In 1996 our group started a clinical knee transplantation project and six transplantations have been performed since. Key problems identified early were the monitoring of acute rejection and choice of an immunosuppressive regime. One graft was lost due to postoperative infection and one due to of noncompliance where the patient discontinued the immunosuppressant regime. In three cases late rejection lead to necrosis and graft dysfunction after 15, 16 and 24 months, respectively. Exit-strategies were arthrodesis in one patient and Above Knee Amputation in two cases. With retrospective analysis after initial five cases the treatment protocol was improved. The immunosuppressive drug regime was altered, femoral diaphysis and knee joint grafting was combined and a vascularized block of donor skin and subcutaneous tissue was harvested with the graft (sentinel skin graft). The sentinel skin graft enabled us to monitor acute rejection by clinical and histological examination and avoid late rejection by rapid treatment with high dose steroids. In summary, over a four-year period, one of six allogeneic vascularized knee transplants has survived, one was lost from a surgical site infection, one by noncompliance and three by late rejection. Analysis of our data leads us to suggest that knee transplantation should be limited to a combined injury consisting of extensive loss of cartilage and bone, deficient extensor mechanism and soft tissue and skin defects without any signs of infection. Transplantation should only be taken into consideration as last option before Above Knee Amputation in an otherwise healthy patient under 35 years of age.