The Pararectus approach: a preferred surgical approach for fixation of acetabular fractures predominantly involving the anterior column - a narrative review.

Beginning in France in the 1960s, the management of acetabular fractures has increasingly evolved toward surgical treatment strategies. The basic principles established by the pioneers of acetabular surgery, Letournel and Judet - anatomical reconstruction of the joint and stable osteosynthesis - remain unchanged. Modern advancements in surgical techniques aim to reduce access-related trauma and minimize complications. The notable rise in acetabular fractures among the elderly, which predominantly affect the anterior aspects of the acetabulum, has driven the development of less invasive, soft tissue-sparing anterior approaches. This evolution began with the ilio-inguinal approach in the 1960s, progressed to the modified Stoppa approach in the 2000s and, most recently, the Pararectus approach in the 2010s. Each of these approaches upholds the fundamental principles of effective acetabular fracture care, while offering distinct advantages and disadvantages. In this review, we examine the merits and limitations of the Pararectus approach, specifically focusing on its utility in the surgical treatment of anterior column posterior hemitransverse acetabular fractures. Ultimately, the success of the individual patient's outcome is less dependent on the chosen approach and more on the surgeon's experience and expertise. Ideally, surgeons should be proficient in all these approaches to tailor the surgical strategy to the individual patient's requirements, thereby ensuring optimal outcomes.

Acetabular fractures in geriatric patients: epidemiology, pathomechanism, classification and treatment options.

The incidence of geriatric acetabular fractures has shown a sharp increase in the last decades. The majority of patients are male, which is different to other osteoporotic fractures. The typical pathomechanism generally differs from acetabular fractures in young patients regarding both the direction and the amount of force transmission to the acetabulum via the femoral head. Geriatric fractures very frequently involve anterior structures of the acetabulum, while the posterior wall is less frequently involved. The anterior column and posterior hemitransverse (ACPHT) fracture is the most common fracture type. Superomedial dome impactions (gull sign) are a frequent feature in geriatric acetabular fractures as well. Treatment options include nonoperative treatment, internal fixation and arthoplasty. Nonoperative treatment includes rapid mobilisation and full weighbearing under analgesia and is advisable in non- or minimally displaced fractures without subluxation of the hip joint and without positive gull sign. Open reduction and internal fixation of geriatric acetabular fractures leads to good or excellent results, if anatomic reduction is achieved intraoperatively and loss of reduction does not occur postoperatively. Primary arthroplasty of geriatric acetabular fractures is a treatment option, which does not require anatomic reduction, allows for immediate postoperative full weightbearing and obviates several complications, which are associated with internal fixation. The major issue is the fixation of the acetabular cup in the fractured bone. Primary cups, reinforcement rings or a combination of arthroplasty and internal fixation may be applied depending on the acetabular fracture type.

The acetabular roof reinforcement plate for the treatment of displaced acetabular fractures in the elderly: results in 59 patients.

INTRODUCTION: Open reduction and internal fixation is considered the gold standard of treatment for displaced acetabular fractures in younger patients. For elderly patients with osteoporotic bone quality, however, primary total hip arthroplasty (THA) with the advantage of immediate postoperative mobilization might be an option. The purpose of this study was to evaluate the clinical and radiological outcomes of surgical treatment of displaced osteoporotic acetabular fractures using the acetabular roof reinforcement plate (ARRP) combined with THA. MATERIALS AND METHODS: Between 2009 and 2019, 84 patients were operated using the ARRP combined with THA. Inclusion criteria were displaced osteoporotic fractures of the acetabulum with or without previous hemi- or total hip arthroplasty, age above 65 years, and pre-injury ability to walk at least with use of a walking frame. Of the 84 patients, 59 could be followed up after 6 months clinically and radiographically. Forty-nine (83%) were primary fractures and 10 (17%) periprosthetic acetabular fractures. RESULTS: The mean age was 80.5 years (range 65-98 years). The average time from injury to surgery was 8.5 days (range 1-28). Mean time of surgery was 167 min (range 100-303 min). Immediate postoperative full weight bearing (FWB) was allowed for 51 patients (86%). At the 6-month follow-up, all 59 patients except one showed bony healing and incorporation of the ARRP. One case developed a non-union of the anterior column. No disruption, breakage or loosening of the ARRP was seen. Additional CT scans performed in 18 patients confirmed bony healing. Twenty-six patients (44%) had regained their pre-injury level of mobility. Complications requiring revision surgery occurred in 8 patients. Five of them were suffering from a prosthetic head dislocation, one from infection, one from hematoma and one from a heterotopic ossification. CONCLUSIONS: The ARRP has proven to provide sufficient primary stability to allow for immediate FWB in most cases and represents a valuable option for the surgical management of displaced acetabular fractures in this challenging patient group.

Enhanced BMP-2-Mediated Bone Repair Using an Anisotropic Silk Fibroin Scaffold Coated with Bone-like Apatite.

The repair of large bone defects remains challenging and often requires graft material due to limited availability of autologous bone. In clinical settings, collagen sponges loaded with excessive amounts of bone morphogenetic protein 2 (rhBMP-2) are occasionally used for the treatment of bone non-unions, increasing the risk of adverse events. Therefore, strategies to reduce rhBMP-2 dosage are desirable. Silk scaffolds show great promise due to their favorable biocompatibility and their utility for various biofabrication methods. For this study, we generated silk scaffolds with axially aligned pores, which were subsequently treated with 10× simulated body fluid (SBF) to generate an apatitic calcium phosphate coating. Using a rat femoral critical sized defect model (CSD) we evaluated if the resulting scaffold allows the reduction of BMP-2 dosage to promote efficient bone repair by providing appropriate guidance cues. Highly porous, anisotropic silk scaffolds were produced, demonstrating good cytocompatibility in vitro and treatment with 10× SBF resulted in efficient surface coating. In vivo, the coated silk scaffolds loaded with a low dose of rhBMP-2 demonstrated significantly improved bone regeneration when compared to the unmineralized scaffold. Overall, our findings show that this simple and cost-efficient technique yields scaffolds that enhance rhBMP-2 mediated bone healing.

[Custom-made glenoid component via 3D print : A rescue prosthetic option for patients with massive glenoid destruction and simultaneous cuff-arthropathy]. / Custom-made-Glenoidkomponente via 3D-Print : Spezielle Prothesenversorgung als finale Behandlungsoption bei massivem Glenoidaufbrauch und gleichzeitiger Rotatorenmanschetten-Defektarthropathie.

The combination of glenoid destruction with cuff arthropathy remains a challenge. A 75-year old woman presented with a post-traumatic loss of the glenoid and concomitant cuff arthropathy. Using CT-data a custom-made glenoid component was created by 3D printing. 6 months after reverse shoulder arthroplasty, the patient was free of pain with acceptable ROM. An individual glenoid component created by 3D printing is a feasible therapeutic option in patients with loss of the glenoid and concomitant cuff arthropathy.

Opening-wedge osteotomies of the distal femur: minor advantages for a biplanar compared to a uniplanar technique.

PURPOSE: Valgus malalignment of the distal femur may be treated with corrective osteotomy. The purpose of this study was to compare the primary stability of a lateral opening-wedge osteotomy (LOWO) using a uniplanar compared to a biplanar technique. A study was carried out to test both surgeries, with both an intact medial cortex and with a deliberate attached cut of the medial cortex simulating a fracture. The primary hypothesis was that the biplanar technique provides higher axial and torsional stiffness. It was further hypothesized that the mechanical superiority of the biplanar technique would not be affected in the case of breakage of the far medial cortex. METHODS: A LOWO was performed in ten synthetic femora (#3406 left large Femur, 4th Generation, Sawbones, Malmö, Sweden) using a lateral angle stable locking plate (NCB© Distal Femur Plate, Zimmer Biomet, Warsaw, USA). A uniplanar osteotomy was performed in five femora, and a biplanar osteotomy was performed in five femora. The femora were tested for axial and torsional loads using a servo-hydraulic testing machine (Instron 8874, Instron Structural Testing GmbH, High Wycombe, UK). RESULTS: Axial stiffness decreased significantly (p = 0.001) in both groups (20% in the uniplanar group and 28 % in the biplanar group) by cutting the medial cortex. The type of osteotomy had no significant effect. A slightly lower but not statistically significant axial stiffness was seen in the biplanar group both for intact and broken medial cortices. Internal torsional stiffness dropped by more than 30% for the uniplanar group and almost 24% for the biplanar group when the cortex was cut (p < 0.001). No significant change concerning internal torsional stiffness was found between the two groups. External torsional stiffness decreased by 32% for the uniplanar group and 4% for the biplanar group after the cortical cut (p = 0.029). No significant change concerning external torsional stiffness was found between the groups, but the biplanar group showed a tendency towards higher values of external torsional stiffness. CONCLUSIONS: The axial and torsional stiffness of the implant-bone construct were not significantly affected by the type of osteotomy performed. Biplanar osteotomy tended to increase external torsional stiffness. In cases of fracture of the medial cortex, biplanar osteotomy significantly reduced the external rotation at the osteotomy and showed a significantly increased external torsional stiffness.

Joint-preserving treatment for type 3 sequelae following fracture of the proximal humerus with small head fragments.

BACKGROUND: Although nonunions of the proximal humerus are rare, they cause significant disability to patients. Surgical reconstruction is challenging, especially with small and excavated head fragments. A promising surgical option is open reduction and stabilization using the Humerusblock device along with tension wires. The aim of this retrospective investigation was to evaluate the clinical and radiological results of this procedure. MATERIALS AND METHODS: Fifteen patients with symptomatic surgical neck nonunions were treated with open reduction and internal fixation using the Humerusblock device without bone grafting. All patients showed a loss of bone stock, leading to excavated head fragments. The mean interval from injury to the described treatment was 6.2 months (range, 3.4-10.7). At a mean follow-up of 40.5 months, the Constant-Murley score was documented, pain and patient satisfaction were evaluated using a visual analogue scale, and x-rays were taken in two planes. RESULTS: The patients' mean age was 69.7 years (range, 52-83). The mean Constant-Murley score improved from 24 points before surgery to 62 points at follow-up, which was an average of 80.8% of the score obtained for the contralateral arm. Radiological examination confirmed bony healing in 14 patients. All but one patient felt satisfied with the results. Three patients required revision surgery because of a hematoma, and early metal removal was performed in one patient because of infection. CONCLUSION: Nonunions of humeral surgical neck fractures can be successfully treated by fixation using the Humerusblock device along with tension wires without the need for additional bone grafting. Especially in patients with flat, concave head fragments, this procedure remains a promising reconstructive option to arthroplasty. LEVEL OF EVIDENCE: Level IV; Therapeutic retrospective case series.

Duration of incapacity of work after tibial plateau fracture is affected by work intensity.

BACKGROUND: Tibial plateau fractures requiring surgery are severe injuries of the lower extremity. Tibial plateau fractures have an impact not only on physically demanding jobs but notably on general professional life too. The aim of this study was to assess how the professional activity of patients will be affected after a tibial plateau fracture. METHODS: 39 consecutive patients (ages 20-61 years) were retrospectively included in the study and were clinically examined at a minimum of 14 month postoperatively. Inclusion criteria were surgical treatment of tibial plateau fractures between November 2009 and December 2012. The clinical evaluation included the Lysholm score and the Oxford Knee Score. Fractures were classified and analyzed using the AO classification. Intensity of work was classified as established by the REFA Association. The patients themselves provided postoperative duration of the incapacity of work and subjective ratings. RESULTS: 17 (43.6%) women and 22 (56.4%) men were examined with a mean follow-up of 29.7 ± 10.4 months (range 14-47). According to the AO classification there were 20 (51.3%) B-type-fractures and 19 (48.7%) C-type-fractures. The median incapacity of work was 120 days (range 10-700 days) with no significant differences between B- and C-type-fractures. Four (10.3%) patients reduced their working hours by 10.5 h per week on average. Patients with low workload (REFA 0-1, median incapacity of work 90 days, range 10-390 days) had a significant shorter incapacity of work than patients with heavy workload (REFA 2-4, median incapacity of work 180 days, range 90-700 days) (p < 0.05). The median Lysholm score decreased significantly from 100 points (range 69-100) before the injury to 73 points (range 23-100) at the time of the follow-up. All patients received postoperative physiotherapy (median 25 appointments, range 6-330), with a significant higher number of appointments for C-type-fractures than for B-type-fractures (p = 0.004). CONCLUSION: A relationship was found between workload and the duration of incapacity of work after tibial plateau fractures. The post-injury shift to less demanding jobs and the reduction of working hours highlight the impact of a tibial plateau fracture on a patient's subsequent physical ability to work.

BMP9 a possible alternative drug for the recently withdrawn BMP7? New perspectives for (re-)implementation by personalized medicine.

Promotion of rhBMP2 and rhBMP7 for the routine use to support fracture healing has been hampered by high costs, safety concerns and reasonable failure rates, imposing restrictions in its clinical use. Since there is little debate regarding its treatment potential, there is rising need for a better understanding of the mode of action of these BMPs to overcome its drawbacks and promote more efficacious treatment strategies for bone regeneration. Recently, BMP9, owing to its improved osteogenic potential, is gaining attention as a promising therapeutic alternative. Our study aimed at identifying specific gene expression patterns which may predict and explain individual responses to rhBMP7 and rhBMP9 treatments. Therefore, we investigated the effect of rhBMP7 and rhBMP9 on primary human osteoblasts from 110 donors and corresponding THP-1-derived osteoclasts. This was further compared with each other and our reported data on rhBMP2 response. Based on the individual donor response, we found three donor groups profiting from rhBMP treatment either directly via stimulation of osteoblast function or viability and/or indirectly via inhibition of osteoclasts. The response on rhBMP7 treatment correlated with expression levels of the genes BAMBI, SOST, Noggin, Smad4 and RANKL, while the response of rhBMP9 correlated to the expression levels of Alk6, Endoglin, Smurf1, Smurf2, SOST and RANKL in these donors. Noteworthy, rhBMP9 treatment showed significantly increased osteogenic activity (AP activity and Smad nuclear translocation) when compared to the two clinically used rhBMPs. Based on patient's respective expression profiles, clinical application of rhBMP9 either solely or in combination with rhBMP2 and/or rhBMP7 can become a promising new approach to fit the patient's needs to promote fracture healing.

Factors circulating in the blood of type 2 diabetes mellitus patients affect osteoblast maturation - description of a novel in vitro model.

Type 2 diabetes mellitus (T2DM) is one of the most frequent metabolic disorders in industrialized countries. Among other complications, T2DM patients have an increased fracture risk and delayed fracture healing. We have demonstrated that supraphysiological glucose and insulin levels inhibit primary human osteoblasts׳ maturation. We aimed at developing a more physiologically relevant in vitro model to analyze T2DM-mediated osteoblast changes. Therefore, SCP-1-immortalized pre-osteoblasts were differentiated with T2DM or control (non-obese and obese) sera. Between both control groups, no significant changes were observed. Proliferation was significantly increased (1.69-fold), while AP activity and matrix mineralization was significantly reduced in the T2DM group. Expression levels of osteogenic marker genes and transcription factors were altered, e.g. down-regulation of RUNX2 and SP-7 or up-regulation of STAT1, in the T2DM group. Active TGF-ß levels were significantly increased (1.46-fold) in T2DM patients׳ sera. SCP-1 cells treated with these sera showed significantly increased TGF-ß signaling (2.47-fold). Signaling inhibition effectively restored osteoblast maturation in the T2DM group. Summarizing our data, SCP-1 cells differentiated in the presence of T2DM patients׳ serum exhibit reduced osteoblast function. Thus, this model has a high physiological impact, as it can identify circulating factors in T2DM patients׳ blood that may affect bone function, e.g. TGF-ß.

Distinct Gene Expression Patterns Defining Human Osteoblasts' Response to BMP2 Treatment: Is the Therapeutic Success All a Matter of Timing?

BACKGROUND: Bone morphogenetic proteins (BMPs) play a key role in bone formation. Local application of BMP2 (Dibotermin alfa) supports bone formation when applied to complex fractures. However, up to 33% of patients do not respond to this therapy. PURPOSE: Aiming to investigate whether inter-individual responses to BMP2 treatment can be predicted by gene expression patterns, we investigated the effect of BMP2 on primary human osteoblasts and THP-1 cell-derived osteoclasts from 110 donors. METHODS: Osteoblasts were obtained by collagenase digestion of spongy bone tissues. Osteoclasts were differentiated from THP-1 cells using the conditioned media of the osteoblasts. Viability was determined by resazurin conversion. As functional characteristics AP and Trap5B activity were measured. Gene expression levels were determined by RT-PCR in 21 of the 110 evaluated donors and visualized by electrophoresis. RESULTS: Based on our data, we could classify three response groups: (i) In 51.8% of all donors, BMP2 treatment induced osteoblast function. These donors strongly expressed the BMP2 inhibitor Noggin (NOG), the alternative BMP2 receptors repulsive guidance molecule B (RGMb) and activin receptor-like kinase 6 (Alk6), as well as the Wnt inhibitor sclerostin (SOST). (ii) In 17.3% of all donors, BMP2 treatment induced viability. In these donors, the initial high SOST expression significantly dropped with BMP2 treatment. (iii) 30.9% of all donors were not directly affected by BMP2 treatment. These donors expressed high levels of the pseudoreceptor BMP and activin membrane-bound inhibitor (BAMBI) and lacked SOST expression. In all donors, SOST expression correlated directly with receptor activator of NF-κB ligand (RANKL) expression, defining the cells' potential to stimulate osteoclastogenesis. CONCLUSIONS: Our data identified three donor groups profiting from BMP2 treatment either directly via stimulation of osteoblast function or viability and/or indirectly via inhibition of osteoclastogenesis, depending on their expression of BAMBI, SOST, NOG, and RANKL. On the basis of patients' respective expression profiles, the clinical application of BMP2 as well as its timing might be modified in order to better fit the patients' needs to promote bone formation or to inhibit bone resorption.

Smoking and unstable hinge fractures cause delayed gap filling irrespective of early weight bearing after open wedge osteotomy.

PURPOSE: The purpose of this study was to examine the osteotomy gap filling rate with new bone after open wedge high tibial osteotomy (HTO) without bone graft and the effects of smoking, lateral hinge fracture, and early full weight bearing. METHODS: A prospective series (N = 70) of open wedge HTOs with the TomoFix plate (DePuy Synthes, Umkirch, Germany) was performed. Radiologic follow-up examinations took place postoperatively, after 6 and 12 weeks, and after 6, 12, and 18 months to measure osteotomy gap filling at each follow-up. Bone healing was compared in smokers versus nonsmokers who underwent open wedge HTOs with intact lateral hinges. Fractured lateral hinges were classified according to the Takeuchi classification and separately analyzed regarding bone healing. Patients were randomly assigned to undergo early (11 days) or standard (6 weeks) full-weight-bearing rehabilitation. RESULTS: A delay in the osteotomy gap filling rate between smokers and nonsmokers could be observed at all follow-up periods, but differences were not significant. A fracture of the lateral hinge was found in 39% of the patients. A type I fracture was observed in 14% of patients, a type II fracture was observed in 13%, and a type III fracture was found in 6%. The highest increase in the osteotomy gap filling rate was observed between 12 weeks and 6 months after surgery in patients with intact lateral hinges. For patients with unstable type II fractures, the highest increase in the gap filling rate was delayed until 6 to 12 months. Early full weight bearing had no effect on the gap filling rate in any of the patient groups evaluated. CONCLUSIONS: This study shows that osteotomy gap filling after open wedge HTO is delayed in smokers and in patients in whom opening of the gap resulted in unstable lateral hinge fractures. Early full weight bearing did not have a significant effect on the gap filling rate. LEVEL OF EVIDENCE: Level III, prognostic study.

Which parameters affect medium- to long-term results after angular stable plate fixation for proximal humeral fractures?

BACKGROUND: Very little information on medium- to long-term results is available for surgically treated proximal humeral fractures. The aim of this prospective treatment study was to present long-term results after angular stable plate fixation of displaced proximal humeral fractures and to detect which specific patient- and fracture-related parameters affect the clinical outcome. METHODS: We performed a prospective clinical and radiologic evaluation of 77 patients with a displaced proximal humeral fracture (28 Neer 2-part, 38 3-part, and 11 4-part fractures; 28 AO A fractures, 30 AO B fractures, and 19 AO C fractures) treated with angular stable plate fixation after a mean follow-up period of 96 months (range, 74-133 months). We assessed outcomes with the Constant, University of California-Los Angeles (UCLA), and Disabilities of the Arm, Shoulder, and Hand (DASH) scores and evaluated specific patient- and fracture-related parameters including complications. RESULTS: The mean Constant, University of California-Los Angeles (UCLA), and Disabilities of the Arm, Shoulder, and Hand (DASH) scores were 79, 31, and 12 points. Reasons for revisions were implant-related impingement (n = 13), screw perforation (n = 10), infection (n = 4), and secondary fracture displacement (n = 1). There was a significant association between worse score results and occurrence of secondary fracture displacement, screw perforation, residual bone deformities, and a rotator cuff defect at follow-up. CONCLUSIONS: Good medium- to long-term results after angular stable plate fixation of displaced proximal humeral fracture can be expected. A reconstruction within a range of 15° in both anteroposterior and axillary views and <5-mm tuberosity displacement should be the aim of head-preserving surgery to prevent complications, such as secondary fracture displacement and screw perforation, and a less favorable long-term result.

Incapacity of work after arthroscopic Bankart repair.

BACKGROUND AND INTRODUCTION: The incapacity with respect to work following anterior-inferior shoulder dislocation and subsequent Bankart repair has not been previously examined. The objective of this study was to examine a patient's incapacity according to the classification by the REFA Association. The recovery time was measured and the outcome of patients with heavy workload was compared to those with lower workloads. MATERIALS AND METHODS: A total of 74 patients who underwent isolated arthroscopic Bankart repair fulfilled the inclusion criteria. The Constant-Murley Score, UCLA Shoulder Score and ROWE Score for Shoulder Instability were recorded for clinical assessment. The mean follow-up time was 43.1 months (SD ± 17.4; 24-110 months) with a mean age of 34.7 years (SD ± 12.6). Workload was classified as per the REFA Association classification system. Postoperative duration of a patient's incapacity with respect to work and other subjective ratings were provided by the patients themselves. RESULTS: The mean incapacity of work was 2.73 months (95 % CI 1.19-5.36). The incapacity of work was 2.06 months (95 % CI 1.55-2.68) in the group with low physical strains at work (REFA 0-1) and 3.40 months (95 % CI 2.70-4.24) in the group with heavy workload (REFA 2-4/p = 0.005). Overall, the mean Constant-Murley Score was 87.7 (SD ± 13.5). The average UCLA Shoulder Score summed up to 31.9 (SD ± 3.87) and the mean ROWE Score was 87.6 (SD ± 21.7). 13 (17.5 %) patients had problems to compete in their jobs. Three patients had to change the job postoperatively. CONCLUSION: In this study, a relationship between the time of incapacity of work and the workload was observed; patients with low physical strains returned significantly earlier to work after arthroscopic Bankart repair (p = 0.005). In general, the clinical results as measured in the Constant/UCLA/Rowe score were comparable to other studies.

Darbepoetin inhibits proliferation of hepatic cancer cells in the presence of TGF-ß.

Darbepoetin (DPO), an erythropoietin (EPO) derivative, was licensed in 2002 to treat patients with solid tumors suffering from chemotherapy-dependent anemia, although various tumors express EPO to improve vascularization, thus favoring tumor growth and spreading. Therefore, we wanted to investigate direct effects of DPO on the liver tumor cell lines HepG2, SkHep1, Huh-7, AKN1, HCC-T and HCC-M, as well as on primary human hepatocytes (hHeps). DPO (0-40 ng/ml) did not affect viability of hHeps, HepG2, SkHep1, AKN1, HCC-T and HCC-M cells, as determined by Resazurin conversion. However, Huh-7 cells' viability dose-dependently decreased from 5 ng/ml DPO on. Lack of LDH release into culture medium and negative DNA laddering excluded apoptosis or necrosis as the cause for the reduced Resazurin conversion. In Huh-7 cells, DPO increased the expression of p53. Interestingly, Huh-7 cells showed the highest basal TGF-ß1 expression as compared to the other cell lines. Upon inhibition of TGF-ß1 signaling, DPO no longer reduced viability in Huh-7 cells. On the contrary, co-incubation with TGF-ß1 made the other cell lines responsive to DPO. Summarizing our data, we show that DPO reduces the growth of Huh-7 cells by up-regulation of the tumor-suppressor gene p53. This mechanism seems to be dependent on a strong TGF-ß expression and corresponding signaling in these cells, as other cell lines became responsive to DPO with TGF-ß1 supplementation. The knowledge of this mechanism offers great perspectives for the understanding and treatment of solid liver tumors.

Chronic CCl4 intoxication causes liver and bone damage similar to the human pathology of hepatic osteodystrophy: a mouse model to analyse the liver-bone axis.

Patients with chronic liver diseases frequently exhibit decreased bone mineral densities (BMD), which is defined as hepatic osteodystrophy (HOD). HOD is a multifactorial disease whose regulatory mechanisms are barely understood. Thus, an early diagnosis and therapy is hardly possible. Therefore, the aim of our study consisted in characterizing a mouse model reflecting the human pathomechanism. Serum samples were collected from patients with chronic liver diseases and 12-week old C57Bl6/N mice after 6-week treatment with carbon tetrachloride (CCl4). Repetitive injections of CCl4 induced liver damage in mice, resembling liver fibrosis in patients, as assessed by serum analysis and histological staining. Although CCl4 did not affect primary osteoblast cultures, µCT analysis revealed significantly decreased BMD, bone volume, trabecular number and thickness in CCl4-treated mice. In both HOD patients and CCl4-treated mice, an altered vitamin D metabolism with decreased CYP27A1, CYP2R1, vitamin D-binding protein GC and increased 7-dehydrocholesterol reductase hepatic gene expression, results in decreased 25-OH vitamin D serum levels. Moreover, both groups exhibit excessively high active transforming growth factor-beta (TGF-ß) serum levels, inhibiting osteoblast function in vitro. Summarizing, our mouse model presents possible mediators of HOD, e.g. altered vitamin D metabolism and increased active TGF-ß. Liver damage and significant changes in bone structure and mineralization are already visible by µCT analysis after 6 weeks of CCl4 treatment. This fast response and easy transferability makes it an ideal model to investigate specific gene functions in HOD.

Dynamic-locking-screw (DLS)-leads to less secondary screw perforations in proximal humerus fractures.

BACKGROUND: Loss of reduction and screw perforation causes high failure rates in the treatment of proximal humerus fractures. The purpose of the present study was to evaluate the early postoperative complications using modern Dynamic Locking Screws (DLS 3.7) for plating of proximal humerus fractures. METHODS: Between 03/2009 and 12/2010, 64 patients with acute proximal humerus fractures were treated by angular stable plate fixation using DLSs in a limited multi-centre study. Follow-up examinations were performed three, six, twelve and twenty-four weeks postoperatively and any complications were carefully collected. RESULTS: 56 of 64 patients were examined at the six-month follow-up. Complications were observed in 12 patients (22%). In five cases (9%), a perforation of the DLS 3.7 occurred. CONCLUSIONS: Despite the use of modern DLS 3.7, the early complications after plating of proximal humerus fractures remain high. The potential advantage of the DLS 3.7 regarding secondary screw perforation has to be confirmed by future randomized controlled trials.

Trends in epidemiology and patho-anatomical pattern of proximal humeral fractures.

PURPOSE: Proximal humeral fractures are common and frequently associated with osteoporosis. Little is known about the association between the patho-anatomical fracture pattern of proximal humeral fractures and patient characteristics. The purpose of this six year longitudinal registry analysis of proximal humeral fractures was to study overall numbers, certain predefined pathoanatomical patterns and distribution compared with specific patient characteristics. METHODS: Data of patients treated between 2006 and 2011 in a country hospital that provides care >95 % of the city's hospitalised patients with fractures was retrospectively reviewed. Data were analysed according to patient characteristics of age, gender, comorbidity, accompanying injuries and radiological analysis of pathoanatomical fracture patterns based on Neer and Arbeitsgemeinschaft für Osteosynthesefragen (AO) classification. RESULTS: Eight hundred and fifteen proximal humeral fractures (67% women/33% men; mean age 66 years, range 19-99) were analysed. During the study period, an overall increase of 42.5% was found: according to AO classification, 46% were type A, 22% type B and 32% type C. Based on the Neer classification, 86% were displaced, and 49% were complex with more than three parts. Of complex fractures, 57% were female patients >60 years. The number of complex fractures was five times higher in women >60 years than in men of the same age group. CONCLUSIONS: An overall increase of inpatients with displaced proximal tibial fractures was documented. Interestingly, complex displaced proximal humeral fractures, especially in older women with comorbidities, accounted for the majority of cases. These results suggest that health-care planning and hospital-based therapeutic strategies should focus on this patient group.

Treatment for unstable distal clavicle fractures (Neer 2) with locking T-plate and additional PDS cerclage.

PURPOSE: The purpose of the current study was to assess the clinical and radiological results after locking T-plate osteosynthesis with coracoclavicular augmentation of unstable and displaced distal clavicle fractures (Neer type 2). METHODS: Thirty patients, treated between January 2007 and January 2010 were followed up after a median follow-up time of 12.2 months (range 4.7-37.2). The Constant and DASH scores were used to evaluate the clinical outcome, and anterior-posterior and 30° cephalic view radiographs were performed to assess the bony healing. RESULTS: In all patients, the fracture healing was achieved within the first 10 weeks after surgery. All patients regained good or excellent shoulder function and returned to previous occupation and activity levels. The mean Constant and DASH scores were 92.3 points and 6.2 points, respectively. We did not observe any severe intra- or post-operative complication within the time of follow-up. CONCLUSION: The presented technique turned out to be a reliable method providing good results without showing severe complications. LEVEL OF EVIDENCE: Case series, Level IV.

CT-based quantitative assessment of the surface size and en-face position of the coracoid block post-Latarjet procedure.

BACKGROUND: The success of shoulder stabilization with the Latarjet procedure might depend on the size of the bone graft and the positioning of the coracoid at the glenoid. The aim of this study was to quantitatively assess the surface of the coracoid bone graft and to assess its positioning in the en-face view. METHOD: A series of 21 patients (17 men, 4 women, 26.1 ± 6.8 years-9 right, 12 left shoulders) were prospectively included and followed up with CT scans between December 2010 and April 2012 at an average of 2.4 ± 0.7 months postoperatively. The retrospective analysis of the CT scans was performed with Osirix™ software. The coracoid surface was measured (cm(2)) in the sagittal plane. The positioning in relation to the center of the circumscribed circle of the glenoid was determined in the en-face clock face view of the glenoid. RESULTS: The grafts had a mean surface of 1.61 ± 0.51 cm(2) (mean ± standard deviation). The coracoid grafts were located between 01:05 hours (32.5°) and 05:33 hours (166.6°). Mean positioning was 02:00 hours (59.8° ± 16.1°) to 04:26 hours (133.0° ± 16.9°). The extent of the grafts was 73.2° ± 14.3°. DISCUSSION: The positioning of the coracoid graft on the clock face of the glenoid is situated in the decisive zone of 02:30-04:20 hours. The mean surface of the graft is smaller than expected from anatomical studies, but restores in defect situations bone stock in the potential defect areas at the anterior glenoid rim. LEVEL OF EVIDENCE: Level IV, prospective case series, treatment study.