Locking Nail versus Plate Fixation in Calcaneal Fractures: Brief report on a Retrospective Analysis of Treatment Characteristics and Radiographic Correction Potential.

PURPOSE OF THE STUDY Minimal and limited access techniques are gaining increasing interest for the treatment of displaced intra-articular calcaneal fractures. The ideal treatment method is however still debated and largely based on individual case factors and surgeon experience. Aim of this study was thus to compare the treatment characteristics and radiographic correction potential of a locking nail system with a sinus tarsi approach to plate fixation via an extended lateral approach. MATERIAL AND METHODS We retrospectively reviewed 39 cases of patients with calcaneal fractures that received primary fracture treatment for displaced intra-articular calcaneal fractures between July 2017 and March 2020. Patient characteristics, time to surgery, time to discharge, OR time and the correction achieved were analyzed and comparative statistics performed. RESULTS In total 19 patients treated with the locking nail and 20 patients treated with plate fixation were analyzed. Patient age and fracture severity according to the Sanders classification were comparable between the groups. Overall surgical time, as well as the achieved reduction was equal between both groups. Time to surgery, as well as time from surgery to discharge was significantly shorter in the locking nail group. 2 additional soft tissue procedures were necessary in the extended lateral approach group. DISCUSSION AND CONCLUSIONS The results with the locking calcaneus nail and sinus tarsi approach suggest, that similar treatment results can be achieved as with plate osteosynthesis and an extended lateral approach. Soft tissue management, as well as pre- and postoperative timing and discharge management can be improved with the nail. Further controlled trials comparing the longterm outcome between the treatment options are needed. Key words: calcaneus fracture, sinus tarsi approach, calcaneal nail, C-Nail.

Weight-Bearing Restrictions after Acetabular Fracture, Necessity or False Hope? A Brief Observational Study.

PURPOSE OF THE STUDY Most common postoperative treatment recommendations after acetabulum fractures suggest at least 6 weeks of postoperative partial or non weight-bearing. To protect the osteosynthetic construct this surgically set weight-bearing limit is trained by physical therapy. Aim of our analysis was to determine the free field patient compliance to these weight-bearing restrictions and observe their influence on the early postoperative radiographic imaging. MATERIAL AND METHODS Patients after surgical treatment of an acetabulum fracture were included in our analysis. Every patient was instructed to maintain a 20 kg weight-bearing limit for 6 weeks. Postoperative weight-bearing was continuously monitored during this time with a pressure measuring insole. Maximum weight-bearing per day was recorded and maintenance of reduction assessed after this time. RESULTS In total 10 patients were included into the study. Only 1 patient stayed within the weight-bearing limit during the analysis. Maximum weight-bearing as high as 110 kg was recorded. All patients maintained postoperative reduction at the 6 week timepoint. DISCUSSION AND CONCLUSIONS Despite regular physical therapy training compliance to the generally accepted weight-bearing limits was low. Regardless of the non-compliance the radiographic outcome remained unchanged. Further analysis on the use of permissive weightbearing aftercare regimes are warranted. Key words: weight-bearing, acetabulum fracture, compliance.

Amlodipine accelerates bone healing in a stable closed femoral fracture model in mice.

Calcium channel blockers (CCBs), which are widely used in the treatment of hypertension, have been shown to influence bone metabolism. However, there is little information on whether CCBs also influence the process of fracture healing. Therefore, the effect of the CCB amlodipine on bone healing was studied in a stable closed fracture model in mice using intramedullary screw fixation. Bone healing was investigated by radiology, biomechanics, histomorphometry and Western blot analysis 2 and 5 weeks after fracture healing. Animals were treated daily (post operatively) per os using a gavage with amlodipine low dose (1 mg/ kg body weight, n = 20), amlodipine high dose (3 mg/kg body weight, n = 20) or vehicle (NaCl) (control, n = 20) serving as a negative control. At 2 and 5 weeks, histomorphometric analysis revealed a significantly larger amount of bone tissue within the callus of amlodipine low-dose- and high-dose-treated animals when compared to controls. This was associated with a smaller amount of cartilaginous and fibrous tissue, indicating an acceleration of fracture healing. Biomechanics showed a slightly, but not significantly, higher bending stiffness in amlodipine low-dose- and high-dose-treated animals. Western blot analysis revealed a significantly increased expression of bone morphogenetic protein (BMP)-2 and vascular endothelial growth factor (VEGF). Moreover, the analysis showed a 5-fold higher expression of osteoprotegerin (OPG) and a 10-fold elevated expression of the receptor activator of NF-κB ligand (RANKL), indicating an increased bone turnover. These findings demonstrated that amlodipine accelerated fracture healing by stimulating bone formation, callus remodelling and osteoclast activity.

Erythropoietin does not improve fracture healing in aged mice.

Fracture healing in the elderly is associated with a declined healing potential caused by multiple factors including a delay of vascularization. Erythropoietin (EPO) has been demonstrated to improve vascularization and fracture healing in adult mice. We, therefore, hypothesized that EPO in aged mice also improves fracture healing. For this purpose, EPO was given daily in a femoral fracture model in aged mice and compared to vehicle-treated controls using radiological, biomechanical, histomorphometric and Western blot techniques. Blood analyses revealed significantly higher concentrations of hemoglobin and a higher hematocrit in EPO-treated animals at 14 and 35 days after fracture. Micro-computed tomography (µCT) indicated that the fraction of bone volume/tissue volume within the callus did not differ between the two groups. However, µCT showed a 3-fold increased tissue mineral density (TMD) in the callus of EPO-treated animals compared to controls. The callus TMD of the EPO-treated animals was also 2-fold higher when compared to the TMD of the unfractured contralateral femur. Interestingly, biomechanical analyses revealed a reduced bending stiffness in femurs of EPO-treated animals at day 35. The histomorphometrically analyzed callus size and callus composition did not show significant differences between the study groups. However, Western blot analyses exhibited an increased expression of osteoprotegerin (OPG), but in particular of receptor activator of NF-κB ligand (RANKL) in the callus of the EPO-treated animals. Further histological analyses of the callus tissue showed that this was associated with an increased number of newly formed blood vessels and a higher number of tartrate-resistant acid phosphatase (TRAP)+ cells. Conclusion: In fracture healing of aged mice EPO treatment increases callus TMD as well as OPG and RANKL expression, indicating an accelerated bone turnover when compared to controls. However, EPO does not improve fracture healing in aged mice. The process of fracture healing may be altered by EPO due to a deterioration of the microcirculation caused by the worsened rheological properties of the blood and due to an increased bone fragility caused by the accelerated bone turnover. Thus, EPO may not be used to improve fracture healing in the elderly.

Effects of locally applied adipose tissue-derived microvascular fragments by thermoresponsive hydrogel on bone healing.

Insufficient vascularization is a major cause for the development of non-unions. To overcome this problem, adipose tissue-derived microvascular fragments (MVF) may serve as vascularization units. However, their application into bone defects needs a carrier system. Herein, we analyzed whether this is achieved by a thermoresponsive hydrogel (TRH). MVF were isolated from CD-1 mice and cultivated after incorporation into TRH, while non-incorporated MVF served as controls. Viability of MVF was assessed immunohistochemically over a 7-day period. Moreover, osteotomies were induced in femurs of CD-1 mice. The osteotomy gaps were filled with MVF-loaded TRH (TRH + MVF), unloaded TRH (TRH) or no material (control). Bone healing was evaluated 14 and 35 days postoperatively. MVF incorporated into TRH exhibited less apoptotic cells and showed a stable vessel morphology compared to controls. Micro-computed tomography revealed a reduced bone volume in TRH + MVF femurs. Histomorphometry showed less bone and more fibrous tissue after 35 days in TRH + MVF femurs compared to controls. Accordingly, TRH + MVF femurs exhibited a lower osseous bridging score and a reduced bending stiffness. Histology and Western blot analysis revealed an increased vascularization and CD31 expression, whereas vascular endothelial growth factor (VEGF) expression was reduced in TRH + MVF femurs. Furthermore, the callus of TRH + MVF femurs showed increased receptor activator of NF-κB ligand expression and higher numbers of osteoclasts. These findings indicate that TRH is an appropriate carrier system for MVF. Application of TRH + MVF increases the vascularization of bone defects. However, this impairs bone healing, most likely due to lower VEGF expression during the early course of bone healing. STATEMENT OF SIGNIFICANCE: In the present study we analyzed for the first time the in vivo performance of a thermoresponsive hydrogel (TRH) as a delivery system for bioactive microvascular fragments (MVF). We found that TRH represents an appropriate carrier for MVF as vascularization units and maintains their viability. Application of MVF-loaded TRH impaired bone formation in an established murine model of bone healing, although vascularization was improved. This unexpected outcome was most likely due to a reduced VEGF expression in the early phase bone healing.

[Work-life balance : Thoughts of the Young Surgeon representatives of the German Surgical Society]. / Work-Life-Balance : Gedanken des Perspektivforums Junge Chirurgie der Deutschen Gesellschaft für Chirurgie.

Work-life balance is a commonly used term that appears in different contexts and has a different meaning for many colleagues. Unfortunately, however, it is often used as a negative, simplified term to describe the assumed attitude of young surgeons towards work and a medical career, even though this is not universally applicable. As the representatives for Young Surgeons of the German Society of Surgery the aim of this article is to present our thoughts on the issue and associated problems and provide a differentiated outline for discussion.

[A new continuous gait analysis system for ankle fracture aftercare]. / Ein neues, kontinuierliches Ganganalysesystem zur Nachbehandlung von Sprunggelenkfrakturen.

BACKGROUND: Correct aftercare following lower extremity fractures remains a controversial issue. Reliable, clinically applicable weight-bearing recommendations have not yet been defined. The aim of the current study was to establish a new gait analysis insole during physical therapy aftercare of ankle fractures to test patients' continuous, long-term compliance to partial weight-bearing restrictions and investigate whether patients can estimate their weight-bearing compliance. MATERIALS AND METHODS: The postoperative gait of 14 patients after operative treatment of Weber B-type ankle fractures was monitored continuously for six weeks (OpenGO, Moticon GmbH, Munich). All patients were instructed and trained by physical therapists on how to maintain partial weight-bearing for this time. Discontinuous (three, six and twelve weeks) clinical (patient questionnaire, visual analogue pain score [VAS]) and radiographic controls were performed. RESULTS: Despite the set weight-bearing limits, individual ranges for overall weight-bearing (range 5-107% of the contralateral side) and patient activity (range 0-366 min/day) could be shown. A good correlation between weight-bearing and pain was seen (rs = -0.68; p = <0.0001). Patients significantly underestimated their weight-bearing time over the set limit (2.3 ± 1.4 min/day vs. real: 12.6 ± 5.9 min/day; p < 0.01). CONCLUSIONS: Standardized aftercare protocols and repeated training alone cannot ensure compliance to postoperative partial weight-bearing. Patients unconsciously increased weight-bearing based on their pain level. This study shows that new, individual and possibly technology-assisted weight-bearing regimes are needed. The introduced measuring device is feasible to monitor and steer patient weight-bearing during future studies.

BMP-2-coated mineral coated microparticles improve bone repair in atrophic non-unions.

Atrophic non-unions are a major clinical problem. Mineral coated microparticles (MCM) are electrolyte-coated hydroxyapatite particles that have been shown in vitro to bind growth factors electrostatically and enable a tuneable sustained release. Herein, we studied whether MCM can be used in vivo to apply Bone Morphogenetic Protein-2 (BMP-2) to improve bone repair of atrophic non-unions. For this purpose, atrophic non-unions were induced in femurs of CD-1 mice (n = 48). Animals either received BMP-2-coated MCM (MCM + BMP; n = 16), uncoated MCM (MCM; n = 16) or no MCM (NONE; n = 16). Bone healing was evaluated 2 and 10 weeks postoperatively by micro-computed tomographic (µCT), biomechanical, histomorphometric and immunohistochemical analyses. µCT revealed more bone volume with more highly mineralised bone in MCM + BMP femurs. Femurs of MCM + BMP animals showed a significantly higher bending stiffness compared to other groups. Histomorphometry further demonstrated that the callus of MCM + BMP femurs was larger and contained more bone and less fibrous tissue. After 10 weeks, 7 of 8 MCM + BMP femurs presented with complete osseous bridging, whereas NONE femurs exhibited a non-union rate of 100 %. Of interest, immunohistochemistry could not detect macrophages within the callus, indicating a good biocompatibility of MCM. In conclusion, the local application of BMP-2-coated MCM improved bone healing in a challenging murine non-union model and, thus, should be of clinical interest in the treatment of non-unions.

[Salvage procedure for painful proximalisation of the 1st metacarpal after trapeziectomy using the Mini TightRope®]. / Die Rettungsoperation mittels Mini TightRope® bei schmerzhafter Proximalisierung des 1. Mittelhandknochens nach Trapezektomie.

PURPOSE: This study analyses our results after revision surgery for failed trapezectomy and suspension arthroplasty with painful proximalisation of the 1(st) metacarpal using the Mini TightRope(®). PATIENTS AND METHODS: In a prospective observational study, 5 patients (4 women and 1 man) with an average age of 62 years were treated with the Mini TightRope(®) for revision of a failed Epping arthroplasty with painful proximalisation of the first ray. The mean time between initial surgery and revision was 23.1 (12.5-31.5) months; the mean follow-up was 25±7.7 (12-32) months. The pain level (visual analogue scale - VAS), pinch grip, and qDASH score were evaluated preoperatively and postoperatively. In addition, the Conolly score was used postoperatively. Directly after surgery and at the last follow-up exam, the degree of proximalisation of the first metacarpal was measured radiologically. RESULTS: At the last follow-up, there was significant mean pain relief during everyday stress, from 5.2 preoperatively to 1.6 (p<0.01) postoperatively, and a significant increase in pinch grip, from 0.5 kg to 3 kg (p<0.01). qDASH improved significantly, from 54 to 20 (p<0.001). The Conolly score showed 2 good and 3 fair results. Renewed proximalisation could not be entirely prevented, but was limited to an average of 2 mm. CONCLUSION: Mini TightRope(®) revision surgery after failed trapezectomy and suspension arthroplasty showes good results with significant pain reduction and gain of function. Renewed proximalisation of the first ray cannot be completely avoided.

Fracture healing redefined.

It is well established that local mechanical conditions and interfragmentary movement are important factors for successful bone healing and may vary dramatically with patient fracture-load and activity. Up until now however it was technically impossible to use these key influence parameters in the aftercare treatment process of human lower extremity fractures. We propose a theory that with state of the art sensor technology these biomechanical influences can not only be monitored in vivo, but also used for individualized therapy protocols. Local measurement systems for fracture healing are available but remain research tools, due to various technical issues. To investigate the biomechanical influences on healing right away surrogate sensor tools are needed. Various gait characteristics have been proposed as surrogate measures. Currently available sensor tools could be modified with the appropriate support structure to allow such measurements continuously over the course of a fracture healing. Interdisciplinary work between clinicians, software engineers with computer and biomechanical simulations is needed. Through such a sensor system human boundary conditions for fracture healing could not only be defined for the first time, but also used for a unique, extendible aftercare system. With this tool critical healing situations would be detected much earlier and could be prevented with easy activity modifications, reducing patient and socioeconomic burden of disease. The hypothesis, necessary tools and support structures are presented.

[Purpura fulminans of the adult--a hematological emergency]. / Purpura fulminans des Erwachsenen--ein hämatologischer Notfall.

HISTORY AND CLINICAL FINDINGS: A 51-year-old female patient with history of longterm drug abuse, was admitted to our hospital with large, stocking-shaped areas of painful, non-displaceable confluent bruising reaching up to the groin. INVESTIGATIONS: The emergency laboratory tests showed leucopenia, thrombocytopenia and anemia as well as a distinct protein C deficiency. DIAGNOSIS, TREATMENT AND COURSE: Purpura fulminans was diagnosed and treated with an initial dose of protein C. The patient survived and the skin necrosis can be treated. CONCLUSION: Purpura fulminans is an internistic and dermatological emergency situation which can lead to shock through consumptive coagulopathy. The serious course of disease can be prevented by rapid treatment with protein C.

[Treatment of a partial avascular necrosis of a metacarpal head (Morbus Mauclaire Dieterich's Disease) utilizing the ostechondral autograft transfer system (OATS) technique]. / Behandlung einer partiellen avaskulären Nekrose eines Mittelhandknochenkopfes (Morbus Mauclaire, Morbus Dieterich) durch Knochen-Knorpel-Transplantation unter Verwendung des Osteochondral Autograft Transfer System (OATS).

The OATS (osteochondral autograft transfer system) is a standardized technique for the treatment of aseptic osteonecrosis of the knee and ankle. We show the first use and successful course of the OAT System for the treatment of a partial aseptic necrosis of a metacarpal head.

The spectrum of toxic shock syndrome.

The toxic shock syndrome (TSS) is a newly-recognized entity caused by a Staphylococcal exotoxin and associated with the use of tampons for menstrual protection. Two cases are presented which demonstrate the spectrum of severity of the disease. The common nature of its early symptoms necessitates a high index of suspicion to preclude a progression to the later stages of the disease, thereby reducing morbidity and mortality.

Radiation exposure of emergency physicians.

Radiation exposure was prospectively measured using film dosimeters worn at the lapel and dominant wrist for up to three two-month intervals in 18 emergency physicians and residents, and was compared to that received by 18 radiology technicians and 18 first-year house staff during similar periods. While all levels were well below maximum permissible doses for occupational exposure, the mean lapel exposures for a two-month period were 14 mrem for the emergency physicians, 26 mrem for radiology technicians, and 7 mrem for the house staff. The difference between the latter two was statistically significant. At the wrist, emergency physicians had a mean of 43 mrem; radiology technicians, 25 mrem; and house staff, 5 mrem. The difference between the first and third groups was statistically significant. No correlation between number of exposures and exposure levels could be detected because of variation in use of protective garments, distance from the beam, and type of exposure. Procedures requiring personnel exposure include those of small children, stress views of the extremities, and studies in the multiply traumatized patient.