[Differences in injury patterns in motorcycle accidents involving children and adolescents]. / Unterschiede der Verletzungsmuster bei Motorradunfällen von Kindern und Jugendlichen.

BACKGROUND: Traffic accidents and the traumatic injury consequences are frequent causes of mortality and irreversible damage in children and young adults. In motorcycle accidents the injury patterns differ depending on the age of the patient. OBJECTIVE: The aim of this study was to describe the typical injury patterns after motorcycle accidents involving children and adolescents as these can have a decisive influence on the prevention and the adequate treatment in the respective patient groups. MATERIAL AND METHODS: The study included 22,923 patients from the years 2002-2018 which were extracted from the TraumaRegister DGU®. Injury patterns of 4 age categories were analyzed: group 1 (4-15 years), group 2 (16-17 years), group 3 (18-20 years) and group 4 (21-50 years). RESULTS: In both younger age groups, limb injuries mostly of the lower extremities, showed the highest incidence. Moreover, younger patients with traumatic brain injury showed better outcomes despite of initially poor conditions. Ribcage, abdominal, pelvic and spinal injuries are the least frequent in younger patients. In terms of diagnostics, children are less likely to undergo whole-body computed tomography (CT) diagnostics than adults. CONCLUSION: The study revealed age-specific differences with respect to injury patterns in patients involved in motorcycle accidents, either as drivers or co-drivers. Furthermore, the analysis of preclinical and in-hospital treatment elucidated the relevance of preventive and protective measures.

[Implications of prehospital estimation of trauma patients for the treatment pathway-An evaluation of the TraumaRegister DGU®]. / Implikationen der prähospitalen Einschätzung des Traumapatienten auf den Behandlungsverlauf ­ Eine Auswertung aus dem TraumaRegister DGU®.

BACKGROUND: In the prehospital acute treatment phase of severely injured patients, the stabilization of the vital parameters is paramount. The rapid and precise assessment of the injuries by the emergency physician is crucial for the initial treatment and the selection of the receiving hospital. OBJECTIVE: The aim of this study was to determine whether the prehospital emergency medical assessment has an influence on prehospital and emergency room treatment. MATERIAL AND METHODS: Data from the TraumaRegister DGU® between 2015 and 2019 in Germany were evaluated. The prehospital emergency medical assessment of the injury pattern and severity was recorded using the emergency physician protocol and compared with the in-hospital documented diagnoses using the abbreviated injury scale. RESULTS: A total of 47,838 patients with an average injury severity score (ISS) of 18,7 points (SD 12.3) were included. In summary, 127,739 injured body regions were documented in the hospitals. Of these, a total of 87,921 were correctly suspected by the emergency physician Thus, 39,818 injured body regions were not properly documented. In 42,530 cases a region of the body was suspected to be injured without the suspicion being confirmed in the hospital. Traumatic brain injuries and facial injuries were mostly overdiagnosed (13.5% and 14.7%, respectively documented by an emergency physician while the diagnosis was not confirmed in-hospital). Chest injuries were underdocumented (17.3% missed by an emergency physician while the diagnosis was finally confirmed in-hospital). The total mortality of all groups was very close to the expected mortality calculated with the revised injury severity classification II(RISC II)-score (12.0% vs. 11.3%). CONCLUSION: In the prehospital care of severely injured patients, the overall injury severity is often correctly recorded by the emergency physician and correlates well with the derived treatment, the selection of the receiving hospital as well as the clinical course and the patient outcome; however, the assessment of injuries of individual body regions seems to be challenging in the prehospital setting.

Loosening of total knee arthroplasty - always aseptic?

PURPOSE: When revision surgery is needed in total knee arthroplasty (TKA) the most frequent reasons are aseptic loosening (AL) and periprosthetic joint infection (PJI). However preoperative distinction between AL and PJI remains challenging. Aim of this study is to determine the incidence of PJI in patients with suspected AL after TKA and to evaluate a diagnostic algorithm for reliable differential diagnosis. METHODS: In this study a total of 149 symptomatic patients with radiographic signs of prosthetic loosening and suspected AL were included. Preoperatively all patients underwent a standardized diagnostic algorithm. For each patient demographics, as well as the results of laboratory and microbiological testing were collected from the medical records. RESULTS: Of the included patients 117 (78.5%) were diagnosed with AL and 32 (21.5%) with PJI. The latency period from primary arthroplasty to the presentation with symptomatic implant loosening was significantly shorter for PJI compared to AL (p < 0.05). The initial CRP values were significantly higher in patients with PJI compared to patients with AL (p < 0.05). Elevated count of white blood cells or percentage of neutrophils within the synovial fluid support the diagnosis of PJI. The sensitivity of synovial cell count (CC) count for PJI in patients with radiographic signs of loosening was 0.84 (CI 0.81-0.87) with a specificity of 0.96 (CI 0.92-0.98). The single best measure for the diagnosis of PJI was synovial fluid cultures with a specificity of 1, however this measure provides poor sensitivity. CONCLUSION: Patients with radiographic signs of loosening in TKA need thorough diagnostics. Information about primary TKA, serological testing, and results of joint aspiration can rule out a PJI in most cases.

Possible risk factors for acute and chronic deep periprosthetic joint infections in primary total knee arthroplasty. Do BMI, smoking, urinary tract infections, gender, and ASA classification have an impact?

PURPOSE: Aim of this retrospective study was to evaluate the impact of the patient related factors body mass index (BMI), urinary tract infection, current smoking, gender, and American Society of Anesthesiologists (ASA) classification on the incidence of acute and chronic deep periprosthetic joint infections (PJI) in total knee arthroplasty (TKA). METHODS: All patients undergoing revision surgery for a deep PJI of primary TKA between July 2012 and December 2016 were included in this study. All relevant data was collected from the medical records. Acute deep PJI was defined when PJI was diagnosed within the first 6 weeks after primary TKA, chronic PJI was defined when patients demonstrated PJI later than 6 weeks after primary TKA. RESULTS: A total of 57 patients was included in this study with 13 cases of acute PJI and 44 of chronic PJI. Overweight patients (BMI > 25 kg/m2) represent a significantly larger proportion in both PJI groups (p < 0.05). Current smokers had an significantly increased risk for acute and chronic PJI (p < 0.05). In the acute PJI group 46.2% patients had an postoperative urinary tract infection. CONCLUSION: An elevated BMI (>25 kg/m2), current smoking and urinary tract infection are possible risk factors for acute and chronic deep PJI. After primary TKA screening for urinary tract infection is recommendable to prevent predominantly acute deep PJI.

Primary cemented bipolar radial head prostheses for acute elbow injuries with comminuted radial head fractures: mid-term results of 37 patients.

BACKGROUND: Radial head arthroplasty represents a widely accepted treatment for elbow injuries with non-reconstructible radial head fractures. The aim of this retrospective multicenter study was to assess mid-term results of patients with clearly defined elbow injuries including type III fractures of the radial head according to Mason's classification type III after primary arthroplasty using a cemented bipolar design. MATERIALS AND METHODS: In 45 cases a primary cemented bipolar arthroplasty of the radial head was implanted for elbow injuries combined with an acute Mason type III radial head fracture. In all patients associated fractures were detected with preoperative CT scans and ligamentous injuries were evaluated and both were addressed intraoperatively based on a standardized algorithm. Patients with associated injuries other than coronoid fractures and collateral ligament tears were excluded from this study to obtain a more homogenous sample. Clinical and radiological assessment was performed on thirty-seven patients at an average of 5.6 years postoperatively. RESULTS: DASH Score, functional rating index of Broberg and Morrey, Mayo Elbow Performance Score, and Mayo Modified Wrist Score confirmed good-to-excellent results in most of the patients. Compared to the unaffected arm range of motion and grip strength were slightly reduced. No elbow instability or loosening of the prosthesis, and minor degenerative changes were detected in a few cases. CONCLUSION: Primary cemented bipolar arthroplasty for type III fractures according to Mason's classification in an elbow injury pattern only including associated coronoid fractures and/or ligamentous tears resulted in good-to-excellent mid-term results. These results suggest that primary bipolar radial head arthroplasty combined with distinct treatment of all associated injuries provides good functional outcomes concerning range of motion, elbow stability, and strength in this cohort. However, the associated injuries may influence clinical and radiological outcome and need to be detected, classified, and treated carefully.

[Distal radius fractures : Current treatment concepts and controversies]. / Die distale Radiusfraktur : Aktuelle Behandlungskonzepte und Kontroversen.

Distal radius fractures represent the most frequent bone fractures in humans. Although the treatment was dominated for decades by conservative measures or closed surgical procedures, such as percutaneous wire osteosynthesis, a paradigm shift was instigated by the introduction and rapid dissemination of volar locking plate osteosynthesis (VLP). The novel procedure was soon proclaimed to be the gold standard and applied for practically all forms of fractures of the distal radius. In addition to clinical mishaps, e.g. failure to address dorsal edge fragments or the occurrence of extensor and flexor tendon irritation, the publication of various prospective randomized studies and meta-analyses led to a certain degree of disillusionment. In comparison to percutaneous wire osteosynthesis, no differences in the clinical result could be established for VLP 1 year postoperatively. It was therefore obvious that not all problems of the distal radius could be solved using the innovative instrument of volar locking plates. This article gives an overview on the current insights and reflects the current expert opinion on the present concepts for the treatment of distal radius fractures. This is illustrated by comprehensive case presentations.

The challenge of Monteggia-like lesions of the elbow: mid-term results of 46 cases.

AIMS: The aim of this retrospective multicentre study was to evaluate mid-term results of the operative treatment of Monteggia-like lesions and to determine the prognostic factors that influence the clinical and radiological outcome. PATIENTS AND METHODS: A total of 46 patients (27 women and 19 men), with a mean age of 57.7 years (18 to 84) who had sustained a Monteggia-like lesion were followed up clinically and radiologically after surgical treatment. The Mayo Modified Wrist Score (MMWS), Mayo Elbow Performance Score (MEPS), Broberg and Morrey Score, and Disabilities of the Arm, Shoulder and Hand (DASH) score were used for evaluation at a mean of 65 months (27 to 111) postoperatively. All ulnar fractures were stabilized using a proximally contoured or precontoured locking compression plate. Mason type I fractures of the radial head were treated conservatively, type II fractures were treated with reconstruction, and type III fractures with arthroplasty. All Morrey type II and III fractures of the coronoid process was stabilized using lag screws. RESULTS: Good results were found for the MMWS, with a mean of 88.4 (40 to 100). There were 29 excellent results (63%), nine good (20%), seven satisfactory (15%), and one poor (2%). Excellent results were obtained for the MEPS, with a mean of 90.7 (70 to 100): 31 excellent results (68%), 13 good (28%), and two fair (4%). Good results were also found for the functional rating index of Broberg and Morrey, with a mean score of 86.6 (57 to 100). There were 16 excellent results (35%), 22 good (48%), six fair (13%), and two poor (4%). The mean DASH score was 15.1 (0 to 55.8). Two patients had delayed wound healing; four patients had nonunion requiring bone grafting. One patient had asymptomatic loosening of the radial head prosthesis. CONCLUSION: Monteggia-like lesions are rare. With correct identification, classification, and understanding using CT scans followed by appropriate surgical treatment that addresses all components of the injury, good to excellent mid-term results can be achieved. Cite this article: Bone Joint J 2018;100-B:212-18.

Treatment of a diaphyseal long-bone defect with autologous bone grafts and platelet-rich plasma in a rabbit model.

INTRODUCTION: Large bone defects are a therapeutic challenge to surgeons and are often associated with a high morbidity. The use of autologous cancellous bone graft represents an essential therapeutic option and is considered the gold standard. However, the use of platelet-rich plasma (PRP) for improving bone defect healing has been discussed controversially. The aim of this study was to evaluate the treatment of a diaphyseal long-bone defect in a rabbit model with a combination of PRP and autologous cancellous bone. MATERIAL AND METHODS: A monocortical long-bone defect in the radial diaphysis of 24 New Zealand white rabbits was filled either with autologous cancellous graft as a control group or with autologous cancellous graft combined with autologous PRP. Histomorphometrical and radiological analysis as well as quantification of platelets and growth factors were performed. The animals were euthanatized after three and six weeks according to the study arms. RESULTS: A significant improvement in bone healing was observed histomorphometrically in the PRP group in the central area of the defect zone (p <0.01) as well as the cortical defect zone (p <0.01). The radiological findings were in accordance with the histomorphometrical results. Comparing native blood and PRP, an enrichment of growth factors and platelets was detectable in the PRP. CONCLUSION: Within this animal study, the combination of PRP and autologous cancellous bone grafts improved bone healing significantly compared to the sole application of autologous bone. Therefore, further efforts should be initiated to establish the composite of PRP and autologous bone for bone healing disorders in clinical use.

Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects.

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non-union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty-four New-Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed.

The effect of bone marrow concentrate and hyperbaric oxygen therapy on bone repair.

Neoangiogenesis represents an essential part of bone regeneration. Therefore the improvement of neovascularization is the subject of various research approaches. In addition autologous mesenchymal stem cells concentrate in combination with bone substitute materials have been shown to support bone regeneration. In a rabbit model we examined the proposed synergistic effect of hyperbaric oxygen therapy (HBOT) and bone marrow concentrate (BMC) with porous calcium phosphate granules (CPG) on neoangiogenesis and osseous consolidation of a critical- size defect. The animal groups treated with HBOT showed a significantly higher microvessel density (MVD) by immunhistochemistry. Furthermore HBOT groups presented a significantly larger amount of new bone formation histomorphometrically as well as radiologically. We conclude that the increase in perfusion as a result of increased angiogenesis may play a key role in the effects of HBOT and consequently promotes bone healing.

Fracture-dislocations of the carpometacarpal joints of the ring and little finger.

We report the functional and radiographic results of 16 patients with fracture-dislocations of the ring and little finger carpometacarpal joints and 23 cases with fracture-dislocations of only the little finger carpometacarpal joint treated between 2006 and 2012. The above two cohort populations of patients were treated with either open reduction and pin fixation or closed reduction and pin fixation. These patients were followed for a mean of 13 months (range 9 to 48). The DASH scores for patients with fracture-dislocations of the ring and little finger carpometacarpal joints were 6.0 and of the little finger carpometacarpal joint 7.2. We found no functional differences in term of DASH scores after treatment between patients with fracture-dislocations of only the little finger carpometacarpal joint and both the ring and little finger carpometacarpal joints.

The treatment of the acute Essex-Lopresti injury.

The Essex-Lopresti injury (ELI) of the forearm is a rare and serious condition which is often overlooked, leading to a poor outcome. The purpose of this retrospective case study was to establish whether early surgery can give good medium-term results. From a group of 295 patients with a fracture of the radial head, 12 patients were diagnosed with ELI on MRI which confirmed injury to the interosseous membrane (IOM) and ligament (IOL). They were treated by reduction and temporary Kirschner (K)-wire stabilisation of the distal radioulnar joint (DRUJ). In addition, eight patients had a radial head replacement, and two a radial head reconstruction. All patients were examined clinically and radiologically 59 months (25 to 90) after surgery when the mean Mayo Modified Wrist Score (MMWS) was 88.4 (78 to 94), the mean Mayo Elbow Performance Scores (MEPS) 86.7 (77 to 95) and the mean disabilities of arm, shoulder and hand (DASH) score 20.5 (16 to 31): all of these indicate a good outcome. In case of a high index of suspicion for ELI in patients with a radial head fracture, we recommend the following: confirmation of IOM and IOL injury with an early MRI scan; early surgery with reduction and temporary K-wire stabilisation of the DRUJ; preservation of the radial head if at all possible or replacement if not, and functional bracing in supination. This will increase the prospect of a good result, and avoid the complications of a missed diagnosis and the difficulties of late treatment.

The early phase influence of bone marrow concentrate on metaphyseal bone healing.

Bone marrow concentrate (BMC) contains high densities of progenitor cells. Therefore, in critical size defects BMC may have the potency to support bone healing. The aim of this study was to investigate the effect of BMC in combination with calcium phosphate granules (CPG) on bone defect healing in a metaphyseal long bone defect in mini-pigs. A metaphyseal critical-size bone defect at the proximal tibia of 24 mini-pigs was filled with CPG combined with BMC, CPG solely (control group) or with an autograft. Radiological and histomorphometrical evaluations after 6 weeks (42 days) showed significantly more bone formation in the BMC group in the central area of the defect zone and the cortical defect zone compared to the CPG group. At the same time the resorption rate of CPG increased significantly in the BMC group. Nevertheless, compared to the BMC group the autograft group showed a significantly higher new bone formation radiologically and histomorphometrically. In BMC the count of mononuclear cells was significantly higher compared to the bone marrow aspirate (3.5-fold). The mesenchymal progenitor cell characteristics of the cells in BMC were confirmed by flow cytometry. Cells from BMC created significantly larger colonies of alkaline phosphatase-positive colony forming units (CFU-ALP) (4.4-fold) compared to cells from bone marrow aspirate. Nevertheless, even in the BMC group complete osseous bridging was only detectable in isolated instances of the bone defects. Within the limitations of this study the BMC+CPG composite promotes bone regeneration in the early phase of bone healing significantly better than the isolated application of CPG. However, the addition of BMC does not lead to a solid fusion of the defect in the early phase of bone healing an still does not represent an equal alternative to autologous bone.

Bone marrow concentrate for autologous transplantation in minipigs. Characterization and osteogenic potential of mesenchymal stem cells.

Autologous bone marrow plays an increasing role in the treatment of bone, cartilage and tendon healing disorders. Cell-based therapies display promising results in the support of local regeneration, especially therapies using intra-operative one-step treatments with autologous progenitor cells. In the present study, bone marrow-derived cells were concentrated in a point-of-care device and investigated for their mesenchymal stem cell (MSC) characteristics and their osteogenic potential. Bone marrow was harvested from the iliac crest of 16 minipigs. The mononucleated cells (MNC) were concentrated by gradient density centrifugation, cultivated, characterized by flow cytometry and stimulated into osteoblasts, adipocytes, and chondrocytes. Cell differentiation was investigated by histological and immunohistological staining of relevant lineage markers. The proliferation capacity was determined via colony forming units of fibroblast and of osteogenic alkaline-phosphatase-positive-cells. The MNC could be enriched 3.5-fold in nucleated cell concentrate in comparison to bone marrow. Flow cytometry analysis revealed a positive signal for the MSC markers. Cells could be differentiated into the three lines confirming the MSC character. The cellular osteogenic potential correlated significantly with the percentage of newly formed bone in vivo in a porcine metaphyseal long-bone defect model. This study demonstrates that bone marrow concentrate from minipigs display cells with MSC character and their osteogenic differentiation potential can be used for osseous defect repair in autologous transplantations.

[Treatment strategy for carpometacarpal fracture dislocation]. / Behandlungsstrategie bei karpometakarpalen Luxationsfrakturen.

Carpometacarpal (CMC) fracture dislocations of the 2nd through 5th ray are rare injuries whose extent is regularly underestimated in the initial radiographic evaluation of the hand. Obtaining a computed tomography scan is imperative due to the radiographic underrepresentation of the full bone and joint injury. Restoration of bone and joint anatomy of the affected region is of paramount import to prevent joint deterioration and loss of hand durability and dexterity. Early surgical intervention can lead to good functional results. Different operative treatment strategies exist with a common approach being Kirschner wire, screw or plate fixation after closed or open fracture reduction and joint relocation.

[Radial nerve palsy associated with humeral shaft fractures - early exploration or expectant procedure? An analysis concerning current strategies of treatment]. / Die primäre N.-radialis-Parese bei Humerusschaftfrakturen - revidieren oder zuwarten? Eine Analyse der Versorgungsrealität in Deutschland.

BACKGROUND: With a prevalence from 11.8 to 18% no fracture is as often associated with nerve damage as the humeral shaft fracture. Whether the radial nerve should be surgically explored in association with a palsy in humeral shaft fractures in order to exclude an interposition or discontinuity is being discussed controversially. The aim of this study was to assess the strategies for primary care of radial nerve palsies associated with humeral shaft fractures in Germany. MATERIAL AND METHODS: In a standardised survey 495 traumatological and 134 neurosurgical clinics were interviewed regarding the treatment of primary radial nerve palsies after humeral shaft fractures. The distribution of the survey included all level-one trauma centres. Statistics were based on the supply strategies, the number of observed contusions, discontinuities and inter-position of the N. radialis in the fracture gap. Moreover, the results were recorded after primary neurorrhaphy. RESULTS: The evaluable response rate to the questionnaire was 56% (university hospitals 77%, level-one trauma centres 63%, level-two trauma centres 70%, level-three trauma centres 44%). 6097 humeral shaft fractures have been treated per year, the incidence of primary radial nerve palsy was 8.6%. Regarding the management strategies, 59% of the hospitals advocated exploration of the nerve, while 25% reported that the decision depends on the individual case. 16% reject the exploration in case of a primary nerve palsy. In the case of an exploration, contusions (74%) of the nerve were largely seen, followed by nerve interpositions in the fracture gap (19%) and discontinuity (7%). In the case of neurorrhaphy, a partial or complete remission was found in 87% of cases. DISCUSSION: Although a primary expectant procedure is recommended in the literature due to the high spontaneous remission rate of 90%, an early exploration of the nerve is often preferred in clinical practice. In these cases, the use of an interlocking intramedullary nail as a minimally invasive treatment option does not appear useful due to the direct exposure of the fracture zone and the radial nerve. Interestingly, the feared discontinuity occurs rarely. The impact of nerve interposition in the fracture gap without surgical exploration remains unclear due to the lack of visibility. CONCLUSION: There is no consensus concerning the treatment of radial nerve palsies after humeral shaft fractures in Germany. Discontinuities are rare, the rate of spontaneous recoveries is high. Whether and when an exploration of the radial nerve is obligatory in primary radial palsy remains unclear and should be clarified by prospective randomised trials.

[Bilateral injuries of the internal mammary artery following blunt thoracic trauma]. / Bilaterale Verletzung der A. thoracica interna nach stumpfem Thoraxtrauma.

Injuries of the internal mammary artery after blunt thoracic trauma are rare but potentially fatal. A specific characteristic of these injuries is that they can become symptomatic even after a delay of several weeks. This article reports on the diagnosis and treatment of a 41-year-old motorcycle rider who suffered bilateral injuries of the internal mammary artery after a motorcycle accident without any additional bony lesions.

The progress of early phase bone healing using porous granules produced from calcium phosphate cement.

OBJECTIVE: Bone grafting is a vital component in many surgical procedures to facilitate the repair of bone defects or fusions. Autologous bone has been the gold standard to date in spite of associated donor-site morbidity and the limited amount of available donor bone. The aim of this study was to investigate the progress of bone regeneration and material degradation of calcium phosphate granules (CPG) produced from a calcium phosphate self-setting cement powder compared to the use of autologous bone grafting in the treatment of "critical size defects" on load-bearing long bones of minipigs. METHODS: A critical size defect in the tibial metaphysis of 16 mini-pigs was filled either with autologous cancellous graft or with micro- and macroporous carbonated, apatic calcium phosphate granules (CPG) produced from a calcium phosphate self-setting cement powder. After 6 weeks, the specimens were assessed by X-ray and histological evaluation. The amount of new bone formation was analysed histomorphometrically. RESULTS: The semi-quantitative analysis of the radiological results showed a complete osseous bridging of the defect in three cases for the autograft group. In the same group five animals showed a beginning, but still incomplete bridging of the defect, whereas in the CPG group just two animals developed this. All other animals of the CPG group showed only a still discontinuous new bone formation. Altogether, radiologically a better osseous bridging was observed in the autograft group compared to the CPG group. Histomorphometrical analysis after six weeks of healing revealed that the area of new bone was significantly greater in the autograft group concerning the central area of the defect zone (p<0.001) as well as the cortical defect zone (p<0.002). All defects showed new bone formation, but only in the autograft group defects regenerated entirely. CONCLUSIONS: Within the limits of the present study it could be demonstrated that autologous cancellous grafts lead to a significantly better bone regeneration compared to the application of calcium phosphate granules (CPG) produced from a calcium phosphate self-setting cement powder after 6 weeks. In the early phase of bone-healing, the sole application of CPG appears to be inferior to the autologous cancellous grafts in an in vivo critical size defect on load-bearing long bones of mini-pigs.