[Severe injury type procedures-Influence of the cipher 11 "complications" and the COVID-19 pandemic on a center for maximum care of severe injuries]. / Schwerstverletzungsartenverfahren ­ Einfluss der Ziffer 11 "Komplikationen" sowie der COVID-19-Pandemie auf ein Haus der traumatologischen Maximalversorgung.

INTRODUCTION: Ensuring the best treatment options for injured patients (healing process, Heilverfahren, HV) is the main goal and responsibility of the German statutory accident insurance (DGUV). The injury type catalogue is the tool to guide the HV. The development of the number of cases treated in a center for severe injury type procedures, the effects of the cipher 11 "complications" of the catalogue and the effects of the COVID-19 pandemic are presented. METHODS: A retrospective study of all patients treated in the context of the DGUV from January 2019 to December 2021 was carried out. The number of cases before and during the legal lockdown actions were compared. The case mix index, the mean number of operations, the mean time in the operating room and the hospital stay were analyzed. Additionally, the cases under the cipher 11 were classified according to the specific anatomical regions. RESULTS: Out of 2007 cases 67% were classified as severe injury type procedures (SAV). Of these cases 51% were categorized to the cipher 11 of the injury type catalogue. Complications were observed particularly in the anatomical regions of the shoulder girdle, elbow, hand, knee, ankle joint and foot. These complex cases are economically not sufficiently represented. During the governmental COVID-19 lockdown actions, the number of patients treated in the context of the DGUV significantly decreased. CONCLUSION: The injury type catalogue is used effectively in the catchment area of the present trauma center. Most of the cases treated in the present trauma center are severe injury type procedures; however, more than half of these cases are classified as complications. This development might show the need for a structural change or an adjustment of the HV. The current comments on the injury type catalogue offer important definitions and specifications; however, the conciseness of the entire catalogue should be maintained.

Autologous Iliac Bone Graft Compared with Biphasic Hydroxyapatite and Calcium Sulfate Cement for the Treatment of Bone Defects in Tibial Plateau Fractures: A Prospective, Randomized, Open-Label, Multicenter Study.

BACKGROUND: Bone-graft substitutes are commonly used for the augmentation of traumatic bone defects in tibial plateau fractures. However, their clinical performance compared with that of autologous bone-grafting, the gold standard in bone defect reconstruction, still remains under debate. This study investigates the differences in quality of life, pain, and radiographic outcomes in the treatment of tibial plateau fracture-associated bone defects with either autologous bone grafts or a bioresorbable hydroxyapatite and calcium sulfate cement (CERAMENT BONE VOID FILLER [CBVF]; BONESUPPORT). METHODS: In this study, 135 patients with acute depression and split-depression fractures of the proximal part of the tibia (OTA/AO types 41-B2 and 41-B3) were enrolled in a prospective, controlled, randomized, multicenter trial including 20 hospitals in Germany. Patients were randomized to receive either autologous iliac bone graft or CBVF for reconstruction of the bone defect. The primary outcome measures were the Short Form (SF)-12 version 2 Physical Component Summary (PCS) score at week 26 (the study was designed to show noninferiority of the CBVF with regard to the PCS with a prespecified margin of -5 points) and the pain level at 26 weeks postoperatively measured by a visual analog scale (VAS). The secondary outcomes were the SF-12 version 2 Mental Component Summary (MCS) and SF-12 PCS scores at weeks 1, 6, and 12 and bone-healing on radiographs. RESULTS: Age, sex, fixation methods, and fracture pattern were comparable in both groups. There were no significant differences (p > 0.05) in the SF-12 PCS or VAS scores at postoperative week 26. There was a significant reduction of blood loss (p = 0.007) and pain levels (p = 0.008) at postoperative day 1 in the CBVF group. The rates of fracture-healing, defect remodeling, and articular subsidence were not significantly different (p > 0.05) in both groups. CONCLUSIONS: Bioresorbable CBVF was noninferior to autologous bone graft with regard to both patient-reported and radiographic outcomes in tibial plateau fractures of OTA/AO types 41-B2 and 41-B3. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Dose-dependent effect of parathyroid hormone on fracture healing and bone formation in mice.

BACKGROUND: Parathyroid hormone (PTH) is the only clinically approved osteoanabolic drug for osteoporosis treatment. However, PTH is not established for the treatment of fracture healing, and doses of PTH diverge significantly between different studies. We hypothesized that the effect of PTH on promoting fracture healing and bone formation is dose dependent. MATERIALS AND METHODS: In vivo, mice were treated with PTH (10, 40, and 200 µg/kg) in a closed femoral fracture model. Fracture healing was analyzed after 4 weeks. The fourth lumbar vertebra was analyzed to assess systemic effects. In addition, osteoblasts from calvaria of mice were treated in vitro with PTH doses of 10-5-50 nM, and their differentiation was analyzed after 26 days. RESULTS: In vivo, PTH dose-dependently stimulated bone formation in the fracture callus and the vertebral body. However, PTH treatment did not increase biomechanical stiffness of the fractured femora in a dose-dependent manner. The increased bone formation in the 200 µg/kg group was associated with a depletion of osteoclasts, indicating diminished bone remodeling. Of interest, in vitro, we observed diminished mineralization with the highest doses of PTH in osteoblast cultures. CONCLUSIONS: PTH dose-dependently stimulates bone formation in vivo. However, during fracture healing, this did not result in a dose-dependent increase of the mechanical stiffness of the fracture callus. Taken together, our in vivo and in vitro data indicate that the dose-dependent effects of PTH during fracture healing are based on the actions on multiple cell types, thereby influencing not only bone formation but also osteoclastic callus remodeling.

Muscle strength quantification in small animals: a new transcutaneous technique in rabbits.

The objective of this study was to develop a new, simple, and noninvasive technique to measure the force produced by dorsi-flexion of the foot in small animals. In addition, this study aimed to quantitatively describe changes in muscle and soft tissue structures using histomorphometry. The recovery of the dorsi-flexing muscles in the tibialis anterior compartment in New Zealand White rabbits was evaluated after musculoskeletal trauma by measuring isometric contractions after submaximal transcutaneous electrical stimulation of the peroneal nerve. The trauma included muscle and bone trauma that was treated with limb shortening followed by distraction osteogenesis. Muscle contractions were initiated at an amplitude of 5.1 mA for a duration of 2.56 ms at intervals of 50 ms. Based on consecutive measurements of the force on days 5, 10, 15, 20, 25, and 30 postsurgery, a positive trend in recovery of the stimulated force produced by dorsi-flexion of the foot was observed. The muscle strength at 30 days postsurgery was compared to that measured presurgery (baseline): 55% of the animals had dorsi-flexion strength that was 60% below that of the presurgery baseline muscle strength; 36% of the animals had dorsi-flexion strength that was greater than 60% of the baseline measure, indicating that there was a significant decrease in force produced by dorsi-flexion of the foot after trauma on all testing days (p < 0.01) and that a severe muscular injury was set with limited recovery. This technique provides a new option for examining muscle regeneration and rehabilitation in small animals.