Weight-bearing Area Research Articles

Repair of high energy injury-induced soft tissue wound of the heel

Objective To investigate the methods and effects of different flaps for repair of high energy injury-induced soft tissue wound of the heel. Methods From January 2002 to June 2012, the patients including 12 males and 9 females aged 18-57 years (mean, 32 years) underwent heel soft tissue defect reconstruction. Causes of injury were traffic injury in 11 case and mechanical injury in 10 cases. Dimension of soft tissue defect ranged from 5 cm×3 cm to 8 cm×6 cm. Soft-tissue defect was repaired with sural neurovascular flaps at the posterolateral heel in 9 cases (Group A), with posterior tibial artery flaps at the posterolateral heel in 5 cases (Group B), and with medial plantar flaps at the loading area of heel in 7 cases (Group C). Sensory recovery and two point discrimination motion of the ankle joint were observed and compared among groups 12 month after operation. Heel pain was observed during weight bearing and joint activity was evaluated using the visual analogue scale (VAS). Results All the flaps survived, except for one with epidermal necrosis over the distal part, which healed after partial changing medication. Duration of follow-up was 12-24 months. There were no differences in the appearance, texture and contour between the flaps and recipient sites. Flaps showed no ulcer in the weight-bearing area and recovered their protective sense. Patients could walk normally after surgery. At postoperative 1 year, sensory recovery rate of the flaps in Groups A, B and C was 0, 20% and 100% respectively (P 0.05). While heel pain existed in weight-bearing exercise.Difference in VAS was significant among the three groups (P 0.05). Conclusion Medial plantar flaps are suitable for tissue defect of 5-8 cm in length but sural neurovascular flaps and posterior tibial artery flaps should be considered for over 8 cm defect in order to elevate survival rate of the flaps and reconstruct limb function. Key words: Foot injuries; Soft tissue injuries; Surgical flaps

Comparison of microstructural and mechanical properties of trabeculae in femoral head from osteoporosis patients with and without cartilage lesions: a case-control study.

BackgroundDegeneration of cartilage will change load distribution, affecting bone remodeling progress and trabecular structure and strength. However, in human primary osteoporosis, whether cartilage lesions would also affect properties beneath trabecular bone remains unknown. In this study, we explored the differences in local trabecular properties between osteoporosis patients with and without cartilage lesions.MethodsEighteen pairs of femoral heads with and without cartilage lesions in a weight-bearing area were collected from senile femoral neck fracture patients. The Mankin score and glycosaminoglycan (GAG) content were used to evaluate the severity of the cartilage lesions. Micro-CT and compression tests were used to obtain structural and mechanical characteristics of each trabecular column. Multivariate linear regression was performed to evaluate the association between mechanical parameters and the degree of cartilage lesion.ResultsIn osteoporosis patients with cartilage lesions, the bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) of the trabecular column were significantly higher than that of osteoporotic control patients (all P < 0.05), while the Young’s modulus was lower (P = 0.024). Multivariable linear regression indicated that in both groups, bone mineral density (BMD) significantly correlated with Young’s modulus (all P < 0.05). While in patients with cartilage lesion, GAG content was also correlated with Young’s modulus (standardized coefficient 0.443, P < 0.01).ConclusionsOsteoporosis patients with cartilage lesions exhibited a weaker mechanical property of trabeculae. The intimate association of cartilage lesions and impairment of trabecular mechanical properties indicate that cartilage and trabeculae belong to an interdependent functional unit. Previously proposed adaptive mechanisms in osteoarthritis might also be applicable to the progression of osteoporosis.

Research of the correlation between knee osteoarthritis of weight-bearing region of the femoral condyle degraded carti-lage matrix biochemical composition and functional imaging of magnetic resonance (T2 mapping)

Objective To investigate the correlation between knee osteoarthritis of weight-bearing region of the femoral condyle degraded cartilage matrix biochemical composition and functional imaging of magnetic resonance. Methods Choose fifteen osteoarthritis cases which conducted TKA between December 2013 and February 2014. There are 7 males and 8 females with an average age of 70 years (range, 62-81 years old). Use 7.0 T magnetic resonance T2-mapping sequence to measure T2 values in weight-bearing area, calculate the water content, collagen content in the same area of cartilage, degrade collagen fiber anisotropy under polarized light microscopy (PLM grade), analyze the correlation between T2 values and collagen fibers to PLM grade. Results The average T2 values were 50.9±2.3 ms in weight-bearing area of knee osteoarthritis articular cartilage for fifteen patients. The average water content was 72.70%±0.2%, and the average collagen content was 5.74±0.2 mg. From PLM grade 1 to 4, the T2 values were 47.68±2.1 ms, 49.62±1.7 ms, 51.36±2.3 ms, 54.89±2.6 ms. The water content were 67.25%±0.3%, 73.80%±0.2%, 75.30%±0.2%, 78.66%±0.3%, and the collagen content were 6.29±0.2 mg, 6.76±0.2 mg, 5.10±0.3 mg, 4.68±0.2 mg. The T2 values and water content increased significantly with the increase of PLM grade. The difference in each grade was statistically significant. The collagen content showed a trend of decline, while the difference in each grade dad no statistically significance. We found that T2 values both positive correlation with water content (r=0.70, P=0.000) and PLM grade (r=0.56, P=0.000), but had no correlation with collagen content (r=0.14, P=0.200). Conclusion The T2 values were positive correlated with the water content and PLM grade of human knee osteoarthritis of weight-bearing region of the femoral condyle degraded cartilage. Use magnetic reso-nance T2-mapping imaging can accurately reflect and evaluate the pathological changes of articular cartilage under the condition of noninvasive. Key words: Magnetic resonance imaging; Osteoarthritis; Cartilage

Biomechanical analysis and clinical efficacy of eccentric rotational acetabular osteotomy

Objective To investigate the biomechanical mechanism and report preliminary clinical efficacy of eccentric rotational acetabular osteotomy (ERAO) when conduct treatment for developmental dysplasia of the hip (DDH). Methods Biome-chanical model of the hip joint was established on six female cadaveric hips embalmed by formalin and stimulate ERAO was then performed on the model. Vertical force was loaded on the cadaveric spine from 0 N to 500 N and strain value on femoral head was measured preoperatively and postoperatively when loading force on spine reached the point of 100, 200, 300, 400 and 500 N. Stress value were then calculated base on the measurements. Besides, we reported postoperative follow-up cases which were underwent ERAO to treat DDH in our hospital from July 2007 to October 2014. A total of 25 patients (26 hips) were reported, including 6 males and 19 females. Age varies from 11 to 57 years old, and the average age was 31 years old. Postoperative hip function was evaluated by Harris hip score and anteroposterior X-ray of pelvic was taken preoperatively and postoperatively to measure the acetabular-head index (AHI), CE angle and sharp angle. Results Preoperative stress increased when loaded on spine became larger, but postoperative stress changed its increasing trend into decreasing when the load was greater than 300 N (turning point), which showed a parabolic trend. Compared with the preoperative stress under different load varying from 100 N to 500 N, postoperative stress was not statistically significant. Meanwhile, by the end of follow-up period, 18 patients (19 hips) were followed form 7 to 85 months. The average follow-up time was 40 months and the follow-up rate was 72%. Harris hip score improved from preoperative 64.3±7.2 points to 85.6±5.3 points; postoperative AHI increased an average of 36.5%, CE angle increased an average of 33.1° and sharp angle reduced an average of 12.3°. All differences between preand post-operative indexes were statistically significant. Conclusion ERAO has the ability to correct the deformity of acetabulum. It enlarges the acetabular coverage of the femoral head and thus reduces the pressure of weight-bearing area. Key words: Hip dislocation, congenital; Osteotomy; Acetabulum; Biomechanics

Modified Stoppa approach for surgical treatment of acetabular fracture.

BackgroundWe analyzed the extent of the comminution in the acetabular weight-bearing area, the clinical and radiographic results, and the complications after a minimum 2-year follow-up of the modified Stoppa approach for the treatment of acetabular fractures, and we attempted to evaluate the efficacy of the operative technique.MethodsAll of the 22 patients, who needed the anterior approach for the treatment of acetabular fractures at our hospital from November 2007 to November 2010, were subjected to surgery via the modified Stoppa approach. Fracture pattern, operative time, blood loss during the operation, quality of reduction, number of bony fragments in the acetabular weight-bearing area, and postoperative complications were assessed by retrospectively analyzing the medical records and the radiographic examinations. The results after the operation were analyzed based on the criteria of Matta.ResultsThe clinical results were excellent in 3 cases, good in 13 cases, and poor in 4 cases, while the radiographic results were excellent in 5 cases, good in 13 cases, and poor in 2 cases. Although the quality of reduction and the clinical results according to the extent of comminution were statistically significant (p = 0.03 and p = 0.04, respectively), the radiographic results were not statistically significant (p = 0.74).ConclusionsIt can be concluded that the modified Stoppa approach could be used as an alternative to the classic ilioinguinal approach. In addition, comminution of the acetabular fracture was an important factor causing non-anatomic reduction and finally unsatisfactory clinical results.

Comparison of dermatoscopic images of acral lentiginous melanoma and acral melanocytic nevus occurring on body weight-bearing areas.

Background:Because body weight-bearing produces a shift in the horny layer, acral melanocytic nevus on the body weight-bearing area of the sole showed a regular fibrillar pattern (FP) due to slanting of the melanin columns in the horny layer. On the other hand, acral lentiginous melanoma (ALM) on the body weight-bearing area of the sole tended to show irregular fibrillar pattern showing rather structureless pigmentation instead of a parallel ridge pattern, which is due to the shift of the horny layer.Objective:To elucidate the subtle difference between the regular FP of nevus and irregular FP in ALM. Methods:In this study, the dermatoscopic features of five cases of ALM and five cases of acral melanocytic nevus on the weight-bearing area of the sole were compared.Results:All the cases with nevi showed regular FP showing regular distribution of fibrils, whereas all the melanomas showed irregular distribution of fibrils and colors. Fibrils in nevi tended to be clear at the furrows and dim at the ridges. White fibrils corresponding to the eccrine ducts in the horny layer were more often present on the ridges in ALM, which showed negative FP.Conclusion:Differentiating between the regular and irregular FP, including negative FP, might be helpful for the discrimination of melanoma from nevus.

Utilizing Mosaicplasty for Cartilage Resurfacing

Osteochondral defects are a significant clinical challenge for orthopaedic surgeons. Patients often experience swelling, clicking, pain, and at times, a feeling of instability. Although some low-demand patients can be adequately managed with nonoperative treatments, active, young patients or older patients with a higher activity level often benefit from surgical intervention for symptomatic lesions. Several surgical therapies exist to treat symptomatic cartilage injuries. Osteochondral autograft transplantation, or mosaicplasty, is an effective treatment for cartilage lesions ranging from 1-5cm 2 . Healthy osteochondral plugs are harvested from the non–weight-bearing areas of the superolateral or superomedial femoral condyles and used to fill the cartilage defect. This provides replacement of congruent hyaline cartilage into a focal defect without the need for cartilage growth, allograft, or synthetic tissue. The procedure is technically demanding, but in the appropriate patient population, several series have had good to excellent results in the medium to long term.

The feasibility study of repairment of articular cartilage defects with bone marrow-derived mesenchymal stem cells seeded on acellular amniotic membrane

Objective To study the effect of repairment of articular cartilage defects in non weight-bearing area of rabbit with bone marrow-derived mesenchymal stem cells (BMSCs) seeded on human acellular amniotic membrane (HAAM).Methods From July 2012 to March 2013,bone marrow-derived mesenchymal stem cells were isolated and purified from rabbit in vitro.The cells were seeded on human acellular anniotic membrane at the concentration of 1.63 × l05/cm2.From 7 days to 8 days after cultured,the complexes of BMSC and HAAM were examined under electronmicroscope,light microscope and by HE stain.Full thickness empty defects measuring 4 mm in diameter by 3 mm depth were prepared in femoral intercondylar fossa of 24 rabbits.The rabbits were randomized into two groups:group A and group B with 12 each group.The defects of right knees were served as control and the left as experimental group.BMSCs/HAAM composite was cultured and then transplanted into the defect of left knee joint in group A as group BMSCs/HAAM and HAAM into group B as group HAAM.These rabbits were killed at 4 and 12 weeks after surgery in each group and the newly cartilage samples were evaluated grossly,histologically are graded.Results In the 4th and 12th week after the operation,the regenerated tissue were white,soft and smooth.Chondrocytes were found in the tissue In the 12th week,the morphology,distribution and arrangement of the regenerated tissues were similar to normal cartilage in the knees with HAAM-BMSCs transplantation.The regenerated tissues grew to be integrated with the surrounding normal cartilage with obscure boundary between them.Chondrocytes were found in all layer of the tissue,surrounding normal cartilage with obscure boundary between them.In the HAAM transplantation,the rough surface of regenerated tissue sunk obviously and the fibmblasts in all layer were found.While there were no regenerated tissue in the control side.Conclusion BMSCs seeded on HAAM could repair the articular cartilage defects of femoral intercondylar fossa from rabbits. Key words: Human acellular amniotic membrane; Bone marrow-derived mesenchymal stem cells; Cartilage defects

Effect of passive motion on articular cartilage in rat osteoarthritis.

The aim of the present study was to investigate the effect of moderate passive motion on articular cartilage in osteoarthritis (OA) caused by knee fracture. Sprague-Dawley rats (age, 8 weeks) with knee fractures were used to construct rat knee early- and middle-stage OA models. The stages were fixed for three and six weeks, with 20 rats analyzed at each stage. The experimental groups were exercised daily for 15 m/min with a specified duration. Following the completion of exercise, the effects of proper passive motion on cartilage thickness, the Mankin rating, cartilage collagen matrix, proteoglycan content and the morphological structure of the cartilage in the rat OA models were measured at the various degenerative stages caused by knee fracture. The proteoglycan content of the cartilage matrix, type II collagen fibers and the number of cartilage cells undergoing apoptosis were semiquantified. For early- and middle-stage OA, the cartilage layers in the three- or six-week experimental groups were significantly thicker and the levels of proteoglycans and type II collagen fibers in the weight-bearing area of the cartilage were significantly higher when compared with the control groups (P<0.05). In addition, the Mankin ratings were lower and ligament tension was increased when compared with the control group (P<0.05). In the early-stage OA group, significantly decreased apoptotic rates (P<0.05) were observed in the three- and six-week experimental groups, however, no significant decrease was observed in the middle-stage OA group. In the early-stage OA rats, the thickness of the cartilage layer, as well as the levels of proteoglycans and type II collagen fibers, in the six-week experimental group, were significantly higher compared with the control and three-week subgroups, and a decreased apoptotic rate was observed (P<0.05). In the six-week experimental middle-stage OA group, significant differences were observed in the content of proteoglycans and type II collagen fibers when compared with the control group, but not when compared with the three-week experimental group. Therefore, proper passive motion can repair and improve the metabolism of chondrocytes and delay the degenerative progress of articular cartilage in OA caused by knee fracture. However, for middle-stage OA, passive motion exhibits no significant repairing effect on the articular cartilage. This therapy increases the levels of proteoglycans and collagen fibers by reducing their decomposition, thereby improving the strength of the articular ligament and the stability of articulation.

A 3D-FEA of Temporomandibular Joint with Reduced Curvature of Curve of Spee

Temporomandibular joint (TMJ) is a weight-bearing joint[1],its biomechanical environment is closely related to bite force. Morphological characteristics of occlusal is an important guide to the bite force conduction. This conduction has an important impact on environmental stress in TMJ. Spee curve is one of the important morphological features of dentition,but study of its curvature changes in relations to joint stress is rarely reported . This study aimed to analyze stress distribution in TMJ when curvature of Curve of Spee decreased. In this study, two kinds of 3D model with diffirent curvatures of Curve of Spee were designed. Model 0: the normal, the curvature was 2.50mm. The vertex was at the cuspis of the second premolar. Model 1: the curvature was 0. Then analyzed by 3D-FEM. The final results validated that the anterior surface of condyle and intermediate zone of articular disc were the weight-bearing areas in TMJ. The stress increased along with curvatures of Curve of Spee decreased.

Thickening of the knee joint cartilage in elite weightlifters as a potential adaptation mechanism

Thickening and increase of area of cartilage have been proposed as two alternative mechanisms of cartilage functional adaptation. The latter has been reported in endurance sportsmen. In weightlifters, extreme strain applied to the articular surfaces can result in other forms of adaptation. The aim of this research is to determine whether cartilage thickness is greater in elite weightlifters than in physically inactive men. Weightlifters (13) and 20 controls [age and body mass index (BMI) matched] underwent knee Magnetic Resonance Imaging (MRI). A single sagittal slice of the knee was taken and cartilage thickness was measured in five and six regions of the medial and lateral femoral condyles, respectively. The analyzed segments represented weight-bearing and nonweight-bearing regions. The tibia cartilage in the weight-bearing area was also measured. The time of training onset and its duration in the weightlifter group were recorded. The cartilage was found to be significantly thicker in weightlifters in most of the analyzed regions. The distribution of cartilage thickness on the medial and lateral femoral condyles was similar in both groups. The duration of training was not associated with cartilage thickness, but the time of training onset correlated inversely with cartilage thickness. It is possible that in high-strain sports, joint cartilage can undergo functional adaptation by thickening. Thus, mechanical loading history could exert a postnatal influence on cartilage morphology.

On Gothic Cathedrals and Contemporary Science

The gothic cathedral is a spectacular achievement of the European Middle Ages. Architecturally, these buildings incorporated revolutionary innovations both in the aesthetics of their design and in their construction. Comparing them to the earlier Romanesque cathedrals, one can observe that the semicircular window arches were substituted with pointed ones. Underneath, the entire weight distribution of the building changed: instead of massive walls, the weight-bearing structures became the buttresses supporting the walls from the outside. This allowed the walls to become much lighter and the buildings higher. Large windows were inserted in non–weight-bearing areas, creating light-filled interior space. Furthermore, fitting the windows with stained glass created interiors where colored light complemented the architecture and highlighted the interior textures (1). Fig. 1 shows one of the northern windows of the Chartres cathedral in France, made in the 13th century. The cathedral was rebuilt in the gothic style after a fire which had destroyed most of the former Romanesque church, and it was consecrated in 1260 by the King of France, Louis IX (who later was canonized as St. Louis). The stained glass provided pictorial versions of the Biblical stories; the one shown here depicts Noah's Ark. The cathedral still has 152 of the …

Utilizing tissue-engineered cartilage or BMNC-PLGA composites to fill empty spaces during autologous osteochondral mosaicplasty in porcine knees

The potential empty spaces between cylindrical plugs remaining after autologous osteochondral mosaicplasty rely on fibrous repair, which may constrain the quality and integrity of the repair. Thus, the empty spaces should be repaired, and how to fill the empty spaces is still a problem. In the present study, a standardized full-thickness defect (diameter, 6 mm) was created in the weight-bearing area of each medial femoral condyle in both knees of 18 miniature pigs. The 36 knees were randomly assigned to four groups with nine in each group. The defects were initially repaired by autologous osteochondral mosaicplasty. Simultaneously, any empty spaces between the multiple plugs were filled with cell-free poly(lactide-co-glycolide) (PLGA) scaffolds (the scaffold group), tissue-engineered cartilage (the TE group) or bone marrow mononuclear cell (BMNC)-PLGA composites (the composite group). The empty spaces were left untreated as control (the control group). Six months after surgery, the repair results were assessed via macroscopic observation, histological evaluation, magnetic resonance imaging, biomechanical assessment and glycosaminoglycan content. The results demonstrated that mosaicplasty combined with the treatment of the empty spaces could improve cartilage regeneration. The filling of empty spaces by tissue-engineered cartilage produced the best result in all the four groups. Meanwhile, utilizing BMNC-PLGA composites achieved a similar repair result. Considering the cost-effective, time-saving and convenient performance, the BMNC-PLGA composite could be an alternative option to fill the empty spaces combined with mosaicplasty. Copyright © 2014 John Wiley & Sons, Ltd.

Fixation of chondral fracture of the weight-bearing area of the lateral femoral condyle in an adolescent

Purely chondral fractures of the distal femur associated with patellar dislocation are uncommon, and treatment varies from fixation to debridement and marrow stimulation techniques. The unusual case reported here involves an adolescent who underwent fixation of a purely chondral fracture involving a large weight-bearing portion of the lateral femoral condyle. Chondral fracture healing was confirmed on follow-up magnetic resonance imaging and arthroscopic examination. This case suggests that fixation of purely chondral fractures can be successful in weight-bearing areas of the knee. Level of evidence V.

The clinical and radiographic results of intertrochanteric curved varus osteotomy for idiopathic osteonecrosis of the femoral head

In this study, postoperative results of intertrochanteric curved varus osteotomy (CVO) for idiopathic osteonecrosis of the femoral head (ION) were studied retrospectively and optimal indication of CVO was considered. Between 1995 and 2011, CVO was performed in 51 patients (53 hips) for the treatment of ION in our department. The patients who had the potential to obtain acetabular coverage of more than one-third of the intact articular surface on pre-operative AP hip radiographs in maximum abduction were considered suitable for this operation. For radiological assessment, a ratio of necrotic volume, a ratio of postoperative intact surface on the weight-bearing area, progression of collapse, shortening length of the lower limb, and lateralization of great trochanter were evaluated. The mean ratio of necrotic volume was 16.9 %. The mean ratio of postoperative intact surface on the weight-bearing area of the femoral head was 51.7 %. The progression of collapse was observed in two hips (ratio of necrotic volume 10.4, 39.8 %; ratio of postoperative intact area 36.5, 38.1 %). The mean shortening length of the lower limb was 9 mm, and the mean lateralization of great trochanter was 3 mm. One hip (ratio of necrotic volume 11.6 %, ratio of intact area 35.8 %) was converted to THA because of the progression of osteoarthritis at 55 months after CVO. The results of CVO for ION were successful, if this procedure was indicated for cases with intact load-bearing area more than 40 %.

Curved periacetabular osteotomy for the treatment of dysplastic hips.

Curved periacetabular osteotomy (CPO) was developed for the treatment of dysplastic hips in 1995. In CPO, the exposure of osteotomy sites and osteotomy of the ischium are made in the same manner as Bernese periacetabular osteotomy, and iliac and pubic osteotomies are performed in the same manner as rotational acetabular osteotomy. We studied the dynamic instabilities of 25 dysplastic hips before and after CPO using triaxial accelerometry. Overall magnitude of acceleration was significantly decreased from 2.30 ± 0.57 m/sec2 preoperatively to 1.55 ± 0.31 m/sec2 postoperatively. Pain relief and improvement of acetabular coverage resulting from acetabular reorientation seem to be related with reduction of dynamic instabilities of dysplastic hips. Isokinetic muscle strengths of 24 hips in 22 patients were measured preoperatively and after CPO. At 12 months postoperatively, the mean muscle strength exceeded the preoperative values. These results seem to be obtained due to no dissection of abductor muscles in CPO. The preoperative presence of acetabular cysts did not influence the results of CPO. An adequate rotation of the acetabular fragment induced cyst remodeling. Satisfactory results were obtained clinically and radiographically after CPO in patients aged 50 years or older. CPO alone for the treatment of severe dysplastic hips classified as subluxated hips of Severin group IV-b with preoperative CE angles of up to -20° could restore the acetabular coverage, weight-bearing area and medialization of the hip joint. CPO without any other combined procedure, as a treatment for 17 hips in 16 patients with Perthes-like deformities, produced good mid-term clinical and radiographic results. We have been performing CPO in conjunction with osteochondroplasty for the treatment of acatabular dysplasia associated with femoroacetabular impingement since 2006. The combined procedure has been providing effective correction of both acetabular dysplasia and associated femoral head-neck deformities without any increased complication rate. We have encountered an obturator artery injury in one case and two intraoperative comminuted fractures. Although serious complications such as motor nerve palsy, deep infection, necrosis of the femoral head or acetabulum, and delayed union or nonunion of the ilium were reported, such complications have never occurred in our 700 cases so far.

Evaluation of the 3D finite element method using a tantalum rod for osteonecrosis of the femoral head.

BackgroundThe aim of this study was to contrast the collapse values of the postoperative weight-bearing areas of different tantalum rod implant positions, fibula implantation, and core decompression model and to investigate the advantages and disadvantages of tantalum rod implantation in different ranges of osteonecrosis in comparison with other methods.Material/MethodsThe 3D finite element method was used to establish the 3D finite element model of normal upper femur, 3D finite element model after tantalum rod implantation into different positions of the upper femur in different osteonecrosis ranges, and other 3D finite element models for simulating fibula implant and core decompression.ResultsThe collapse values in the weight-bearing area of the femoral head of the tantalum rod implant model inside the osteonecrosis area, implant model in the middle of the osteonecrosis area, fibula implant model, and shortening implant model exhibited no statistically significant differences (p>0.05) when the osteonecrosis range was small (60°). The stress values on the artificial bone surface for the tantalum rod implant model inside the osteonecrosis area and the shortening implant model exhibited statistical significance (p<0.01).ConclusionsTantalum rod implantation into the osteonecrosis area can reduce the collapse values in the weight-bearing area when osteonecrosis of the femoral head (ONFH) was in a certain range, thereby obtaining better clinical effects. When ONFH was in a large range (120°), the tantalum rod implantation inside the osteonecrosis area, shortening implant or fibula implant can reduce the collapse values of the femoral head, as assessed by other methods.

Proteomic Analysis Profile of Engineered Articular Cartilage with Chondrogenic Differentiated Adipose Tissue-Derived Stem Cells Loaded Polyglycolic Acid Mesh for Weight-Bearing Area Defect Repair

The present study was designed to investigate the possibility of full-thickness defects repair in porcine articular cartilage (AC) weight-bearing area using chondrogenic differentiated autologous adipose-derived stem cells (ASCs) with a follow-up of 3 and 6 months, which is successive to our previous study on nonweight-bearing area. The isolated ASCs were seeded onto the phosphoglycerate/polylactic acid (PGA/PLA) with chondrogenic induction in vitro for 2 weeks as the experimental group prior to implantation in porcine AC defects (8 mm in diameter, deep to subchondral bone), with PGA/PLA only as control. With follow-up time being 3 and 6 months, both neo-cartilages of postimplantation integrated well with the neighboring normal cartilage and subchondral bone histologically in experimental group, whereas only fibrous tissue in control group. Immunohistochemical and toluidine blue staining confirmed similar distribution of COL II and glycosaminoglycan in the regenerated cartilage to the native one. A vivid remolding process with repair time was also witnessed in the neo-cartilage as the compressive modulus significantly increased from 70% of the normal cartilage at 3 months to nearly 90% at 6 months, which is similar to our former research. Nevertheless, differences of the regenerated cartilages still could be detected from the native one. Meanwhile, the exact mechanism involved in chondrogenic differentiation from ASCs seeded on PGA/PLA is still unknown. Therefore, proteome is resorted leading to 43 proteins differentially identified from 20 chosen two-dimensional spots, which do help us further our research on some committed factors. In conclusion, the comparison via proteome provided a thorough understanding of mechanisms implicating ASC differentiation toward chondrocytes, which is further substantiated by the present study as a perfect supplement to the former one in nonweight-bearing area.

Comparison of plantar pressures and contact area between normal and cavus foot

BackgroundIn pes cavus, the medial longitudinal arch elevation reduces the contact surface area and consequently increases the corresponding plantar pressure measurements. This poor distribution of loads may produce associated pathology and pain in this or other areas of the body. Normal reference values need to be established in order to determine which patterns are prone to pathology. ObjectivesTo compare the plantar pressures and weight-bearing surface in a population with pes cavus to a population with neutral feet. MethodThe sample comprised 68 adults, 34 with pes cavus and 34 with neutral feet. The Footscan USB Gait Clinical System® was used as a platform to measure the total contact area and plantar pressure under the forefoot, midfoot, hindfoot, each metatarsal head, and the overall metatarsal area. A statistical analysis of the data was performed using Student's t-test for independent samples. ResultsThe pes cavus subjects showed a significant reduction in their weight-bearing area [neutral feet: 165.04 (±20.68)cm2; pes cavus: 118.26 (±30.31)cm2; p<0.001] and significantly increased pressures under all zones of the forefoot except the fifth metatarsal [metatarsal pressure: in neutral feet 503,797 (±9.32)kPa; in pes cavus 656.12 (±22.39)kPa; p<0.001]. ConclusionsCompared to neutral feet, pes cavus feet show a reduction in total contact surface and the load under the first toe. A significant increase is present in the load under the metatarsal areas, but the relative distribution of this load is similar in both groups.

Complex Heel Reconstruction with a Sural Fasciomyocutaneous Perforator Flap

Reconstruction of weight-bearing surfaces at the foot and ankle is controversial. Free tissue transfer and local fasciocutaneous perforator flaps are preferred for plantar reconstruction, but high rates of flap breakdown and ulceration have caused unsatisfactory functional outcomes. We present a modified "sural fasciomyocutaneous perforator flap" and its functional outcome. Between January 2007 and September 2010, 19 patients were treated for soft-tissue defects in the weight-bearing area with sural fasciomyocutaneous perforator flaps. The gastrocnemius, preserved in the base of the flap, was applied as padding under the calcaneus. In follow-up from 9 to 25 months (mean 13.8 months), each patient's pain score, defect size, ulcer formation, protective sensation recovery, and normal footwear were analyzed. The majority of the flaps survived with satisfactory aesthetic and functional results. One case of partial flap loss and one case of delayed ulceration were noted. With partial weight bearing at 4 weeks, satisfactory gait recovery was obtained at 5 to 8 months (in conjunction with protective sensation recovery). Sural fasciomyocutaneous perforator flap is a reliable modality in heel construction, showing advantages of low ulceration rate, durability, and good protective sensation recovery compared with conventional free tissue transfer and local fasciocutaneous perforator flap.