Intramedullary Nailing vs Sliding Hip Screw in Trochanteric Fracture Management: The INSITE Randomized Clinical Trial.

Importance: Fractures of the hip have devastating effects on function and quality of life. Intramedullary nails (IMN) are the dominant implant choice for the treatment of trochanteric fractures of the hip. Higher costs of IMNs and inconclusive benefit in comparison with sliding hip screws (SHSs) convey the need for definitive evidence. Objective: To compare 1-year outcomes of patients with trochanteric fractures treated with the IMN vs an SHS. Design, Setting, and Participants: This randomized clinical trial was conducted at 25 international sites across 12 countries. Participants included ambulatory patients aged 18 years and older with low-energy trochanteric (AO Foundation and Orthopaedic Trauma Association [AO/OTA] type 31-A1 or 31-A2) fractures. Patient recruitment occurred between January 2012 and January 2016, and patients were followed up for 52 weeks (primary end point). Follow-up was completed in January 2017. The analysis was performed in July 2018 and confirmed in January 2022. Interventions: Surgical fixation with a Gamma3 IMN or an SHS. Main Outcomes and Measures: The primary outcome was health-related quality of life (HRQOL), measured by the EuroQol-5 Dimension (EQ5D) at 1-year postsurgery. Secondary outcomes included revision surgical procedure, fracture healing, adverse events, patient mobility (measured by the Parker mobility score), and hip function (measured by the Harris hip score). Results: In this randomized clinical trial, 850 patients were randomized (mean [range] age, 78.5 [18-102] years; 549 [64.6% female) with trochanteric fractures to undergo fixation with either the IMN (n = 423) or an SHS (n = 427). A total of 621 patients completed follow-up at 1 year postsurgery (304 treated with the IMN [71.9%], 317 treated with an SHS [74.2%]). There were no significant differences between groups in EQ5D scores (mean difference, 0.02 points; 95% CI, -0.03 to 0.07 points; P = .42). Furthermore, after adjusting for relevant covariables, there were no between-group differences in EQ5D scores (regression coefficient, 0.00; 95% CI, -0.04 to 0.05; P = .81). There were no between-group differences for any secondary outcomes. There were also no significant interactions for fracture stability (ß [SE] , 0.01 [0.05]; P = .82) or previous fracture (ß [SE], 0.01 [0.10]; P = .88) and treatment group. Conclusions and Relevance: This randomized clinical trial found that IMNs for the treatment of trochanteric fractures had similar 1-year outcomes compared with SHSs. These results suggest that the SHS is an acceptable lower-cost alternative for trochanteric fractures of the hip. Trial Registration: ClinicalTrials.gov Identifier: NCT01380444.

Clinical pathways for geriatric patients with proximal femoral fracture improve process and outcome.

OBJECTIVE: The objective of the current study was to evaluate the implementation of clinical pathways (CPs) in hip fracture management. METHODS: Six hundred and five proximal femoral fractures were prospectively included into a hospital data-base. The effects of CPs were evaluated using a pre-during-post design. Different procedural (time to surgery, length of stay, discharge, etc.) and patient outcome parameters (mortality, complications, etc.) were evaluated. RESULTS: In both categories significant changes could be detected during the three-year period. E.g. significant reduction of time to surgery, improvement of discharge management, reduction of internal complications. However, no significant changes could be demonstrated for mortality or revision rate. CONCLUSION: We could show a relevant improvement with the implementation of clinical pathways for the treatment of proximal femoral fractures in elderly patients. LEVEL OF EVIDENCE: III, prospective non-randomised cohort study.

Continuous improvement process: ortho-geriatric co-management of proximal femoral fractures.

OBJECTIVE: The objective of the current study was to evaluate the effect of a quality management system on treatment and care delivery of proximal femoral fractures. Specifically, our hypothesis was that the "plan-do-check-act (PDCA)" philosophy of the ISO 9001 quality management system results in a continuous improvement process. METHODS: 1015 proximal femoral fractures were prospectively included into a hip fracture database over a 5-year period, after a restructuring process with implementation of clinical pathways and standard operation procedures. A close and structured ortho-geriatric co-management (certified ortho-geriatric center) was the basis for treatment. ISO 9001 certification was granted for the first time in 2012. Procedural and patient outcome parameters were analyzed by year and evaluated statistically using SPSS 25.0. RESULTS: In both categories (procedural and outcome) significant changes could be detected during the 5-year period, e.g., significant reduction of time to surgery for the first 2 years, improvement in discharge management, and reduction of surgical complications. However, no significant changes could be demonstrated for mortality or internal complications such as pneumonia, urinary tract infections, or postoperative delirium. However, the incidence of the latter was already on a very low level at the onset of the quality improvement process. CONCLUSION: We could show a relevant and continuous improvement of several quality indicators during a 5-year period after implementation of a quality management system based on the PDCA philosophy for the treatment of proximal femoral fractures in elderly patients. However, other parameters (internal complications, cost-effectiveness, etc.) need our close attention in the future.

Value of 3D Reconstructions of CT Scans for Calcaneal Fracture Assessment.

BACKGROUND: The interpretation of CT scans for the evaluation of calcaneal fractures is difficult. Three-dimensional (3D) reconstruction (volume rendering technique [VRT]) has been valuable in the evaluation of irregularly shaped bones. However, their value for the analysis of calcaneal fractures is still debated. Therefore, the objective of this study was to assess the effect of additional use of 3D CTs in calcaneal fractures. METHODS: In a prospective multicenter study, the CT data set of 5 different fractures was presented to 57 evaluators. First, the participating surgeons were asked to assess the fractures on the basis of axial, coronal, and sagittal reconstructions using a multiple-choice questionnaire. Second, 3D reconstructions (VRT) were presented. The CT scans were validated by the intraoperative findings and the results were compared to the model solution of 3 foot and ankle surgeons. Intra- and interrater reliabilities were calculated. RESULTS: The proportion of intraobserver agreement was 82%, with Cohen kappa of κ = 0.748 (P < .001). Interrater agreement varied between 0.772 (P = .006) for the assessment of concomitant fractures and 0.987 (P < .001) for the suggested approach. The evaluation of several items improved after presentation of the 3D CTs (Cochrane Q test, P < .001). The benefit of 3D imaging was higher in inexperienced surgeons and complex fractures (Friedman test P < .001). CONCLUSION: The evaluation of CT scans of calcaneal fractures was improved by the additional use of 3D images (VRT). LEVEL OF EVIDENCE: Level II, prospective comparative study.

Bionic plate design for calcaneal fracture treatment. A biomechanical analysis and first clinical results.

PURPOSE: Calcaneal fracture treatment is challenging. Implant failure is one problem encountered with plate osteosynthesis. Therefore a new "bionic" plate was developed, which imitates the trabecular orientation of the human calcaneus. The aim of this study was to biomechanically test this new plate in comparison to a "standard" calcaneal locking plate and present the first clinical results. METHODS: Six "bionic" and six "standard" calcaneal plates were biomechanically tested for stability and fatigue using synthetic calcanei. Between 4/2012 and 04/2013 the first ten consecutive patients meeting the inclusion criteria were treated with the novel implant and followed-up clinically and radiologically. The 12-month follow-up results are reported. RESULTS: The "bionic" plate design showed significantly higher fatigue life (68%), load to failure (100%) and reduced displacement under load (90%) if compared to a "standard" locking plate. No major complications were seen; most notably there was no implant failure and no loss of reduction. Mean AOFAS/hindfoot score was 79 (69-86). CONCLUSIONS: The novel plate architecture offers higher stability and load tolerance while being more resistant to fatigue. The preliminary clinical results are promising. These findings will have to be proved by larger clinical trials.

Midterm results after modified Epping procedure for trapeziometacarpal osteoarthritis.

BACKGROUND AND PURPOSE: Various surgical procedures have been proposed for the treatment of trapeziometacarpal joint (TMJ) osteoarthritis. Despite an overall satisfactory outcome in most cases, some patients complain about inadequate performance at work, due to instability of the TMJ. We present a cross-sectional study of patients with TMJ arthritis who underwent a modified Epping procedure for increased TMJ stability. METHODS: 71 patients underwent a modified Epping procedure with a flexor carpi radialis tendon sling stabilizer. 59 patients were followed up after a mean time of 38 months. Residual pain was evaluated by visual analog scale. Functional outcome was quantified by pinch and grip strength, static two-point discrimination test, as well as DASH outcome scoring. Quality of life measures included patients' perceived satisfaction, activities of daily living (ADL), grip/pinch force and manual performance at work. RESULTS: 85 % of the patients regained full or partial manual performance during labor. Strength and ADL improved or remained the same in 81 %. In cases of a unilateral treatment, no difference in grip between the operated and nonoperated hand was observed. Mean tip pinch strength was 2.8 kg for the operated and 3.6 kg for the nonoperated hand. Mean pain level during rest was 0.98, 0.95 during mild activity, and 3.70 during strenuous activity. Mean DASH score was 26.6. CONCLUSION: The great majority of patients who underwent this novel procedure benefited from an unaffected or improved work performance, due to good TMJ stability combined with adequate motion for ADL. Less favorable results were seen in patients with accompanying hand pathologies.

Incidence and outcome of atlanto-occipital dissociation at a level 1 trauma centre: a prospective study of five cases within 5 years.

BACKGROUND: Prospective evaluation of atlanto-occipital dissociations (AODs) at a level 1 trauma centre within 5 years. METHODS: Over a period of 5 years (2005-2009), all CT scans of the skull base and the upper cervical spine due to traumatic injuries were prospectively entered into a database. Furthermore, in cases of confirmed AOD all empirical data were prospectively collected. A more detailed data analysis of all AOD patients was conducted 2 years post-trauma. If required, another prospective follow-up was performed. RESULTS: 2,616 CT scans were performed in total. Out of these, there were five male patients with confirmed AOD. Thus, the total incidence was 0.2 %. AOD was associated with occipital condyle fractures in three out of the five cases. Three out of five patients (60 %) died due to the severity of the injury. It was possible to stabilise two patients surgically with a clinical/radiological follow-up 2 years post-surgery. At that time, one patient had an incomplete tetraplegia and was wheelchair ridden without needing ventilation, while the other patient suffered from post-traumatic stress disorder, but was able to walk and live alone. CONCLUSIONS: AOD is a rarely seen injury, even in a level 1 trauma centre, and is associated with high morbidity and mortality. However, it is possible for adults to survive this severe occipito-cervical injury after surgical repair while maintaining the ability to walk. All the results and recommendations are still based on a low level of evidence, due to the low incidence of this injury.

Occipital condyle fractures. Prospective follow-up of 31 cases within 5 years at a level 1 trauma centre.

PURPOSE: Prospective investigation of incidence and outcome of occipital condyle fractures (OCF) in a level 1 trauma centre. METHODS: Over a period of 5 years, we prospectively recorded all cases of OCF, and performed a 1-year post-injury radiological and clinical follow-up using CT imaging, SF-36 and Neck Disability Index, respectively. RESULTS: A total of 31 patients with OCF were identified. Based on a total of 2,616 CT scans that had been performed during this period, the incidence was 1.19%. There were 27 unilateral and 4 bilateral OCFs. Furthermore, 3 out of 31 patients (9.7%) were additionally diagnosed with atlanto-occipital dislocation (AOD), one of which was dorsally stabilised in a surgical procedure. All other patients were treated conservatively. 5 out of 31 patients (16.1%) died due to the severity of associated injuries. 22 out of 31 patients (70.9%) were prospectively followed-up for 1 year after trauma. During this period, CT imaging showed bony consolidation of fractures in all cases except for one, with no evidence of secondary dislocation or nonunion. Evaluation of the Neck Disability Index showed moderate disability. The SF-36 questionnaire showed an impaired quality of life in all areas; however, these were determined by associated injuries and independent of the type of fracture. CONCLUSIONS: Both unilateral and bilateral OCFs represent a stable injury regardless of the type of fracture. If AOD has been diagnosed in addition, it requires surgical stabilisation-independent of the OCF-and it is a significant predictor for poor outcomes. The patients quality of life 1 year after trauma has not been affected by the OCF, but by the overall pattern of the injury and by comorbidities. Based on our results, we introduce a new, simple and practical classification for OCFs.

How reliable are CT scans for the evaluation of calcaneal fractures?

INTRODUCTION: CT scans are deemed to be the gold standard for the evaluation of calcaneal fractures. However, the reliability of the interpretation has not been studied systematically. PATIENTS AND METHODS: In a prospective multicenter study, the CT data set of five different fractures was presented to 57 evaluators. The participating surgeons were asked to assess calcaneal fractures on the basis of a multiple choice questionnaire. The CT scans were validated by the intraoperative findings. The questionnaires were compared to the model solution of three foot and ankle surgeons. The intra- and interrater reliability was calculated. RESULTS: The proportion of intraobserver agreement was 82%. Cohen's kappa was κ = 0.748 with P < 0.0001. In total, 61% of the items were answered similarly to the model answer. Only 27% of the evaluators were able to correctly classify the fracture according to Sanders and 63% of the evaluators agreed that surgical procedure was necessary. The more experienced the surgeon, the higher was the interrater agreement. CONCLUSION: This is the first study to systematically analyze the reliability of the interpretation of CT scans of calcaneal fractures. This was found to be unsatisfactory. Future studies must show, if specific interventions, e.g., teaching programs or image procession modalities (e.g., 3D reconstructions), are capable of improving the quality of interpretation of CT scans for calcaneal fractures.

Post-traumatic fulminant paradoxical fat embolism syndrome in conjunction with asymptomatic atrial septal defect: a case report and review of the literature.

INTRODUCTION: Fat embolism syndrome with respiratory failure after intramedullary nailing of a femur fracture is a rare but serious complication in trauma patients. CASE PRESENTATION: We present the case of a 20-year-old Caucasian man who experienced paradoxical cerebral fat embolism syndrome with fulminant progression after intramedullary nailing of a femur fracture, in conjunction with a clinically asymptomatic atrial septal defect in a high position resulting in a right-to-left shunt. CONCLUSION: Fat embolism syndrome may occur as a fulminant complication following femoral fracture repair in the presence of a concomitant atrial septal defect with right-to-left shunt. Thus, in patients with cardiac right-to-left shunts, femurs should not be nailed intramedullary, not even in cases of isolated injuries.

Outcome after complex trauma of the foot.

BACKGROUND: In 1997, H. Zwipp. proposed a 5-point scoring system for the classification of complex trauma of the foot. However, outcome and quality of life after this type of injury have not been studied systematically. PATIENTS: Seventy-four patients with a complex injury of the foot were treated between 2001 and 2007. Fifty patients met the inclusion criteria for a prospective cross-sectional study. American Foot and Ankle Society score, the Short Form 12, and the Visual Analogue Scale-Foot and Ankle Score were recorded. All patients were examined by an experienced orthopedic surgeon and a certified pedorthist. Functional assessment was completed by dynamic baropedography. RESULTS: Primary amputation was necessary in 11, secondary amputation in 7 patients. A compartment syndrome was diagnosed in 29 patients. Soft tissue coverage was achieved in eight patients using a free vascular flap. The complication rate was 32%. Mean follow-up was 4 years (1-7 years). At that time, the American Foot and Ankle Society score was 66.2, the Short Form 12 score 38.2 (physical health component scale), and the Visual Analogue Scale-Foot and Ankle score was 51.9. Orthopedic shoes were necessary in 44% of the patients; however, compliance was low, and 52% of the orthopedic devices were insufficient. Pedographic evaluation demonstrated changes in gait in 82% of the patients. CONCLUSION: Early outcome after complex trauma of the foot was essentially determined by soft tissue injury, whereas long-term outcome was determined more by the trauma of the bones and joints. Objective measurements such as dynamic pedography helped to better understand patients' limitations. Orthotic supply could be improved in a reasonable number of the patients.

Calcaneocuboid joint involvement in calcaneal fractures.

BACKGROUND: The reported incidence of calcaneocuboid joint (CCJ) involvement in calcaneal fractures varies considerably. It is largely unknown to what extent CCJ involvement accounts for outcome in these fractures. Therefore, the goal of this study was to analyze the incidence and effects of CCJ involvement in calcaneal fractures. METHODS: The clinical records of 106 patients, treated between 2000 and 2004, were reviewed for fracture classification, injury mechanism, surgical treatment, and complications. In a prospective cross-sectional study, 44 patients were assessed clinically (SF-36 American Orthopaedic Foot and Ankle Society score) and radiographically. Gait analysis was performed using dynamic pedography. RESULTS: Sixty-eight percent of all fractures had involvement of the CCJ. Fractures with CCJ involvement were caused by a more severe injury than fractures without CCJ involvement (Mann-Whitney U test, p = 0.03); this is reflected by a strong association between CCJ involvement and fracture classification (Spearman, p < 0.006). Patients with involvement of the CCJ-especially those with a postoperative step in the CCJ-achieved a lower SF-36 score as well as a lower American Orthopaedic Foot and Ankle Society score than patients without CCJ involvement. CCJ involvement was associated with more difficulties in walking on rough surface (Spearman, p = 0.020). Limitations during gait were confirmed by dynamic pedography. Grading of posttraumatic osteoarthritis was associated with fracture classification (chi test p < 0.02) and quality of reduction (chi test p < 0.01). CONCLUSIONS: These results indicate that calcaneal fractures with involvement of the CCJ are associated with more severe trauma and worse outcome. Thus, the CCJ should be given more credit during surgery and in our research efforts.

Influence of the growth factors PDGF-BB, TGF-beta1 and bFGF on the replicative aging of human articular chondrocytes during in vitro expansion.

Decreasing replicative potential and dedifferentiation of articular chondrocytes during expansion in cell culture are essential limitations for tissue engineering and cell therapy approaches. Telomeres and telomerase play a key role in cell development, aging, and tumorigenesis. There is evidence that growth factors are involved in regulating telomerase activity. Therefore, the objective was to evaluate the effect of selected growth factors on telomere biology of serially passaged chondrocytes. Human articular chondrocytes were isolated from cartilage of three patients undergoing total knee arthroplasty. The chondrocytes were cultured in monolayer with the growth factors PDGF-BB, TGF-beta1, and bFGF. Telomere length was measured by telomere restriction fragment length assay, and telomerase activity was determined by quantifying the gene expression of its catalytic subunit hTERT by rtPCR. Chondrocytes cultured with PDGF-BB and TGF-beta1 showed a significantly higher proliferation rate than control cells. None of the growth factor cultures revealed an accelerated rate of telomere shortening. Telomerase was not expressed in significant amounts in any of the chondrocyte cultures. Growth factor treatment of chondrocyte cell cultures for cell therapy purposes can be regarded as safe in terms of telomere biology.

The use of 'fasciocutaneous' and 'osteofasciocutaneous' parascapular flaps for lower limb reconstruction: a retrospective study of 20 patients.

BACKGROUND: The parascapular flap is a widely accepted and suitable option for covering defects in almost all anatomical areas. Here, we report our experience with the microvascular transfer of parascapular flaps for the coverage of large lower leg defects with reference to our retrospective study. PATIENTS AND METHODS: Twenty patients with free parascapular flaps (17 male, three female, age: 43+/-17 years, BMI 26.1+/-3.5) were examined 3 months to 3 years after free tissue transfer. All procedures and examinations were performed by the same experienced surgeon (2002-2005). Flap dimensions ranged from 8 x 4 cm to 30 x 13 cm, with an average of 20.4+/-6.6 cm x 8.9+/-2.6 cm. The parameters studied included perioperative morbidity, donor site morbidity, flap vitality, complications, functional shoulder tests, patient satisfaction (visual analog scale, VAS), the duration of the hospital stay and the long-term outcome. RESULTS: All of the 20 flaps remained vital. Adequate coverage and complete healing were obtained in all patients during the follow-up period and all patients were physically mobile. General patient satisfaction with the intervention was high (VAS: median 7.5; x(25)=6.0; x(75)=9.5); donor site morbidity was low, that is, only one patient presented with reduced range of motion and shoulder function compared to the preoperative status. The hospital stay after flap transfer was 20.8+/-9.8 days and the overall hospital stay was 32.1+/-15.0 days. CONCLUSIONS: Our study confirms that the parascapular flap is a very versatile and safe flap for lower limb reconstruction with low donor morbidity.

A woman with a dangling digit.

Ainhum (dactylolysis spontanea) is a distinct clinical and radiological disorder of dark-skinned people characterized by a progressive development of a constricting band encircling the toe which usually results in spontaneous amputation. Ainhum mainly occurs in African natives, but in times of global migration and tourism, Ainhum is likely to be more often encountered outside Africa. Even though the clinical presentation can mimic more common entities such as arthritis and trauma, the correct diagnosis and treatment is easy if one knows this unusual entity.

Functional donor-site morbidity following (osteo-) fasciocutaneous parascapular flap transfer.

PROBLEM: The parascapular flap is extremely versatile in the armamentarium of the plastic surgeon. However, little is known about the donor-site morbidity. Our purpose was to investigate limitations and problems arising at the donor site of parascapular flaps. METHODS: Twenty patients with free parascapular flaps were followed up over a period of 3 years. Donor-site morbidity was evaluated using standardized evaluation forms. Constant score was calculated to judge shoulder function, SF-36 score was used to evaluate patient satisfaction. RESULTS: All flaps survived in our series. In 2 patients, delayed wound healing was recorded at the donor site. In 3 patients, shoulder function was limited. In 1 patient, the brachial plexus was affected, and another had preexisting rotator cuff disease. Scar dimensions varied considerably; however, cosmetic aspects of the donor site were not a complaint. DISCUSSION: This is the first report evaluating donor-site morbidity of parascapular flaps. Limitations in shoulder function are low if correct operative technique with refixation of the musculature is maintained. In general, patients did not have any complaints about the cosmetic appearance of the donor site.

Cyclic, mechanical compression enhances chondrogenesis of mesenchymal progenitor cells in tissue engineering scaffolds.

The effects of cyclic, mechanical compression on human bone marrow-derived mesenchymal progenitor cells undergoing chondrogenic differentiation were examined in this study. Mesenchymal progenitor cells were injected into cylindrical biodegradable scaffolds (hyaluronan-gelatin composites), cultured in a defined, serum-free chondrogenic medium and subjected to cyclic, mechanical compression. Scaffolds were loaded for 4 hours daily in the first 7 days of culture. At 1, 7, 14 and 21 days of culture, scaffolds were harvested for reverse transcriptase Polymerase Chain Reaction (RT-PCR), histology, quantitative DNA, proteoglycan and collagen analysis. Scaffolds loaded for 7 days showed a significant upregulation especially of chondrogenic markers (type II collagen, aggrecan; p<0.0001). No significant difference could be found for DNA content between loaded samples and unloaded controls. At day 1 in culture no significant differences in proteoglycan- and collagen contents could be detected between unloaded and loaded samples. After 21 days the proteoglycan (p<0.001) and collagen contents (p<0.0001) were significantly higher in the loaded samples compared to unloaded controls. By histological analysis (toluidine blue) a higher amount of proteoglycan-rich, extracellular matrix production throughout the matrix could be detected for loaded samples compared to unloaded controls. This study indicates that cyclic, mechanical compression enhances the expression of chondrogenic markers in mesenchymal progenitor cells differentiated in vitro resulting in an increased cartilaginous matrix formation, and suggests that mechanical forces may play an important role in cartilage repair.

Influence of different collagen species on physico-chemical properties of crosslinked collagen matrices.

Collagen-based scaffolds are appealing products for the repair of cartilage defects using tissue engineering strategies. The present study investigated the species-related differences of collagen scaffolds with and without 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC)/N-hydroxysuccinimide (NHS)-crosslinking. Resistance against collagenase digestion, swelling ratio, amino acid sequence, shrinkage temperature, ultrastructural matrix morphology, crosslinking density and stress-strain characteristics were determined to evaluate the physico-chemical properties of equine- and bovine-collagen-based scaffolds. Three-factor ANOVA analysis revealed a highly significant effect of collagen type (p=0.0001), crosslinking (p=0.0001) and time (p=0.0001) on degradation of the collagen samples by collagenase treatment. Crosslinked equine collagen samples showed a significantly reduced swelling ratio compared to bovine collagen samples (p< 0.0001). The amino acid composition of equine collagen revealed a higher amount of hydroxylysine and lysine. Shrinkage temperatures of non-crosslinked samples showed a significant difference between equine (60 degrees C) and bovine collagen (57 degrees C). Three-factor ANOVA analysis revealed a highly significant effect of collagen type (p=0.0001), crosslinking (p=0.0001) and matrix condition (p=0.0001) on rupture strength measured by stress-strain analysis. The ultrastructure, the crosslinking density and the strain at rupture between collagen matrices of both species showed no significant differences. For tissue engineering purposes, the higher enzymatic stability, the higher form stability, as well as the lower risk of transmissible disease make the case for considering equine-based collagen. This study also indicates that results obtained for scaffolds based on a certain collagen species may not be transferable to scaffolds based on another, because of the differing physico-chemical properties.

Contractile forces generated by articular chondrocytes in collagen-glycosaminoglycan matrices.

The objective of the study was to directly measure the force of contraction of adult articular chondrocytes and to examine their contractile behavior in collagen-glycosaminoglycan analogs of extracellular matrix by live cell imaging in vitro. The contractile forces generated by passages 2 and 3 adult canine articular chondrocytes were measured using a cell force monitor. The contractile behavior of the cells was also directly imaged as they were cultured in collagen-glycosaminoglycan scaffolds. Passage 2 cells seeded in a collagen-glycosaminoglycan scaffold were capable of generating a force of 0.3 nN/cell. Chondrocytes subcultured through a third passage generated a force twice that level, paralleling the increase in the alpha-smooth muscle actin (SMA) content of the cells as demonstrated by Western blot analysis. Treatment of passage 3 cells with staurosporine reduced the force of contraction by approximately one-half, reflecting the effects of this agent in reducing the SMA content of the cells and disrupting the microfilaments. These values compare with 1 nN previously reported for lapine dermal fibroblasts of passage 5-7, using the same apparatus. Direct live cell imaging documented the contractile behavior of the articular chondrocytes in the collagen-glycosaminoglycan matrix in the time frame in which the force was directly measured in the cell force monitor. This imaging demonstrated how the cells acted individually and in unison to buckle the collagen struts making up the matrix. Adult articular chondrocytes are capable of generating a SMA-enabled force of contraction sufficient to model extracellular matrix molecules.

Is there a reliable outcome measurement for displaced intra-articular calcaneal fractures?

BACKGROUND: The treatment of displaced intra-articular calcaneal fractures remains controversial, because of difficulties in assessing the outcome. The goal of this study, therefore, was to compare different outcome measurements with gait analysis, using dynamic pedography. METHODS: Twenty patients with operatively treated displaced intra-articular calcaneal fractures were followed up clinically and radiographically. In addition, foot pressure was measured using dynamic pedography. RESULTS: No significant difference was found between the two clinical outcome scores used (p = 0.08); both revealed good results. Dynamic pedography, however, showed a shift of the maximum impact and roll-off of the foot to the lateral side, as well as a widening of these zones in the heel and on the sole in 14 of 20 patients. CONCLUSION: These results indicate that traditional outcome measurements underestimate functional deficits in our patients. Monitoring plantar pressure distribution might therefore be a useful tool for assessing foot function in these patients.