骨软骨镶嵌移植术与微骨折术治疗膝关节软骨损伤的疗效比较

目的:对比评估微骨折术与自体骨软骨镶嵌移植术治疗膝关节软骨损伤的临床疗效差异。方法 :回顾性分析2011年2月至2016年2月采用微骨折术或自体骨软骨镶嵌移植术治疗且随访时间≥2年的71例膝关节股骨远端关节面软骨损伤患者资料,按手术方式不同分为两组:微骨折组33例,男20例,女13例,年龄(28.1±4.2)岁;移植组38例,男26例,女12例,年龄(27.8±3.5)岁。采用Lysholm评分,美国特种外科医院膝关节评分(Hospital for Special Surgery Knee Score,HSS),Ahlb覿ck骨关节炎分级系统进行评估,并记录术后并发症。结果 :微骨折组与移植组的Lysholm评分,分别由术前62.9±6.8、60.3±7.5提高到术后的77.0±5.4、85.8±5.6 (P0.05);HSS评分分别由术前81.5±7.6、79.6±8.6改善为88.0±4.7、91.9±4.7(P0.05)。移植组术后Lysholm评分与HSS评分,均高于微骨折组(P0.05)。移植组发生切口浅表感染1例。随访未发现患者出现膝关节骨关节炎。结论:自体骨软骨镶嵌移植术与微骨折术治疗膝关节软骨损伤均安全、有效,但自体骨软骨镶嵌移植术比微骨折术临床疗效更佳。     

Chondroprotective effect of alendronate in a rabbit model of osteoarthritis

The aim of this study was to determine how alendronate (ALN) alters cartilage degeneration and periarticular bone quality in a rabbit anterior cruciate ligament transection (ACLT) model of osteoarthritis (OA). Thirty rabbits underwent an ACLT on the left knee and a sham operation on the right knee. Fifteen rabbits received weekly subcutaneous injections of ALN (0.14 mg/kg) and 15 rabbits (the control [cont] group) received saline. Animal knees were divided into four groups: cont/sham, cont/ACLT, ALN/sham, and ALN/ACLT. Histological, radiological, and immunohistochemical indices were evaluated for each group. Bone volume ratios by micro‐computed tomography showed that ALN prevented periarticular bone loss. Histologically, the cont/ACLT group had significantly worse cartilage damage than the cont/sham group 12 weeks after the surgery. However, the ALN/ACLT group had mild cartilage degeneration compared with that of the ALN/sham group. Immunohistochemical analysis showed that ALN suppressed the expression of matrix metalloproteinase‐13, interleukin‐1β, type‐X collagen, vascular endothelial growth factor, and receptor activator of nuclear factor κB ligand in OA cartilage. ALN had a chondroprotective effect in an experimental rabbit model of OA. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1572–1577, 2011     

Osteoporosis increases the severity of cartilage damage in an experimental model of osteoarthritis in rabbits

OBJECTIVE: To evaluate the effect of osteoporosis (OP) in cartilage damage developed in an experimental model of osteoarthritis (OA) in mature female rabbits in order to investigate the relationship between OP and OA. METHODS: OA was experimentally induced by anterior cruciate section and partial medial meniscectomy in the left knee of 12 rabbits. OP was experimentally induced prior to OA in six rabbits by bilateral ovariectomy (OVX) and systemic corticosteroid administration during 4 weeks. Knees were evaluated with high resolution magnetic resonance imaging (MRI) before knee surgery to rule out any detrimental effect of corticosteroids on cartilage. Gross and microscopic cartilage changes were assessed 16 weeks after surgery in bilateral knees. Left knees were considered osteoarthritic or osteoarthritic plus osteoporotic. Right knees were used as osteoporotic and healthy controls, respectively. Bone mineral density (BMD) was measured with dual energy X-ray absorptiometry (DXA) at the lumbar spine, global knee and subchondral knee bone, and its variations correlated with cartilage abnormalities. RESULTS: MRI before knee surgery disclosed no cartilage or bone abnormalities in any of the studied groups. OP increased the severity of cartilage abnormalities in experimental knee OA significantly (P<0.05). Cartilage damage was inversely correlated with BMD variations measured at the lumbar spine (r=-0.74; P=0.015). BMD changes in global and subchondral knee bone also showed a trend to correlate inversely with cartilage damage. CONCLUSIONS: Prior induction of OP increases the severity of cartilage damage in experimental OA. Increase in cartilage damage correlates with bone loss. These findings suggest a direct relationship between OP and OA.     

Autologous osteochondral grafting in the knee: indication,results, and reflections

The use of multiple autologous osteochondral plugs (mosaicplasty) for repair of articular cartilage defects is a well-accepted technique. Since 1995, the authors have used mosaicplasty to treat more than 110 patients with cartilage defects of the knee, hip, and ankle. The first 52 consecutive patients who had mosaicplasty of the knee and have an average followup of 37 months (range, 24-56 months) were examined. Indications for surgical treatment were osteochondritis dissecans, acute trauma, and posttraumatic lesions of the femorotibial joint, femoropatellar maltracking with recurrent episodes of patella dislocations, and distinct femoropatellar arthrosis. Preoperatively, cartilage defects were classified as International Cartilage Repair Society Grade III lesions in 23 patients and Grade IV lesions in 29 patients. Two years after surgery, an increased level of knee function was found in 86% of the patients. At the latest followup, improved knee function was observed in 92% of the patients. In four patients, reoperation was necessary because of graft failure. Complications and reoperation rate were related to large surface lesions. Autologous osteochondral transplantation is a valid option for the treatment of full-thickness osteochondral defects. However, the method is limited by the defect size and the number of plugs to be taken at the donor site.     

Three-year changes in bone mineral density around the knee after a six-month course of oral alendronate following total knee arthroplasty. A prospective, randomized study

BACKGROUND: Bone mineral density decreases after total knee arthroplasty and is believed to affect prosthetic fixation. Treatment with alendronate has been shown to improve short-term bone mineral density after total knee arthroplasty; however, the long-term effects of this therapy are unknown. The purpose of this study was to evaluate the long-term effects of a six-month course of alendronate on bone mineral density after total knee arthroplasty. METHODS: Sixty patients were randomly assigned to receive either oral alendronate at a dosage of 10 mg/day for six months or no alendronate. The bone mineral density in the distal aspect of the femur and the proximal aspect of the tibia was measured preoperatively and at six, twelve, and thirty-six months after total knee arthroplasty. RESULTS: Fifty-four patients (twenty-nine in the alendronate group and twenty-five in the control group) completed the study. The alendronate group showed significant increases in bone mineral density in the distal aspect of the femur compared with the controls at six months (+4.8% and -14.2%, respectively; p < 0.01) and twelve months (+1.6% and -11.5%, respectively; p < 0.01). No significant difference in bone mineral density was detected between the groups at thirty-six months (-3.9% and -12.2%, respectively; p = 0.08). Similar trends in bone mineral density changes were also observed in the proximal aspect of the tibia. CONCLUSIONS: A six-month course of alendronate initially increased bone mineral density at six and twelve months after total knee arthroplasty, but no difference was noted after thirty-six months. The effect of alendronate on bone mineral density after total knee arthroplasty may be limited after discontinuation of therapy.     

Minimum ten-year results of a prospective randomised study of autologous chondrocyte implantation versus mosaicplasty for symptomatic articular cartilage lesions of the knee

Autologous chondrocyte implantation (ACI) and mosaicplasty are methods of treating symptomatic articular cartilage defects in the knee. This study represents the first long-term randomised comparison of the two techniques in 100 patients at a minimum follow-up of ten years. The mean age of the patients at the time of surgery was 31.3 years (16 to 49); the mean duration of symptoms pre-operatively was 7.2 years (9 months to 20 years). The lesions were large with the mean size for the ACI group being 440.9 mm(2) (100 to 1050) and the mosaicplasty group being 399.6 mm(2) (100 to 2000). Patients had a mean of 1.5 previous operations (0 to 4) to the articular cartilage defect. Patients were assessed using the modified Cincinnati knee score and the Stanmore-Bentley Functional Rating system. The number of patients whose repair had failed at ten years was ten of 58 (17%) in the ACI group and 23 of 42 (55%) in the mosaicplasty group (p < 0.001). The functional outcome of those patients with a surviving graft was significantly better in patients who underwent ACI compared with mosaicplasty (p = 0.02).     

Effects of the systemic administration of alendronate on bone formation in a porous hydroxyapatite/collagen composite and resorption by osteoclasts in a bone defect model in rabbits

Several bisphosphonates are now available for the treatment of osteoporosis. Porous hydroxyapatite/collagen (HA/Col) composite is an osteoconductive bone substitute which is resorbed by osteoclasts. The effects of the bisphosphonate alendronate on the formation of bone in porous HA/Col and its resorption by osteoclasts were evaluated using a rabbit model. Porous HA/Col cylinders measuring 6 mm in diameter and 8 mm in length, with a pore size of 100 μm to 500 μm and 95% porosity, were inserted into a defect produced in the lateral femoral condyles of 72 rabbits. The rabbits were divided into four groups based on the protocol of alendronate administration: the control group did not receive any alendronate, the pre group had alendronate treatment for three weeks prior to the implantation of the HA/Col, the post group had alendronate treatment following implantation until euthanasia, and the pre+post group had continuous alendronate treatment from three weeks prior to surgery until euthanasia. All rabbits were injected intravenously with either saline or alendronate (7.5 μg/kg) once a week. Each group had 18 rabbits, six in each group being killed at three, six and 12 weeks post-operatively. Alendronate administration suppressed the resorption of the implants. Additionally, the mineral densities of newly formed bone in the alendronate-treated groups were lower than those in the control group at 12 weeks post-operatively. Interestingly, the number of osteoclasts attached to the implant correlated with the extent of bone formation at three weeks. In conclusion, the systemic administration of alendronate in our rabbit model at a dose-for-weight equivalent to the clinical dose used in the treatment of osteoporosis in Japan affected the mineral density and remodelling of bone tissue in implanted porous HA/Col composites.     

No mid-term difference in mosaicplasty in previously treated versus previously untreated patients with osteochondral lesions of the talus

Introduction Osteochondral transplantations, albeit technically challenging, appear promising not only in knee joint lesions, but also in the treatment of talus lesions. We hypothesized that in patients suffering osteochondral lesions of the talus, favorable outcomes are obtained in patients undergoing primary mosaicplasty as compared to patients undergoing secondary mosaicplasty. Materials and methods Over a 3-year period (1998–2001), 14 patients (six male, eight female, median age 22 years) were treated with an autologous osteochondral transplantation of the talus. Eight patients were previously untreated (group I). Six patients had previous ankle procedures, such as microfracturing (group II). The median follow-up was 24 months and 100% complete at 12 months. The functional outcome was evaluated at least at 6 weeks, 12 weeks, and 1 year after surgery using pain on a visual analog scale (VAS) and sports activity was recorded at 1 year after surgery. In ten patients, magnetic resonance imaging (MRI) of the ankle was performed at 1 year after surgery (group I/II: 7/3). Results Overall ankle pain was decreased from 6.9 ± 2.1 to 4.0 ± 2.8 postoperatively. The mean knee pain for the donor knee was 2.6 ± 2.4. We found no significant difference between the primary mosaicplasty group and the secondary mosaicplasty group with regard to pain. MRI scans of ten patients showed a complete incorporation of the osteochondral cylinders at 1 year after surgery. Conclusion Favorable outcomes were obtained in patients undergoing primary mosaicplasty as compared to patients undergoing secondary mosaicplasty. We found no significant difference among patients with previous ankle surgery in contrast to those without, with a median 24-months follow-up.     

A prospective,randomised comparison of autologous chondrocyte implantation versus mosaicplasty for osteochondral defects in the knee

Autologous chondrocyte implantation (ACI) and mosaicplasty are both claimed to be successful for the repair of defects of the articular cartilage of the knee but there has been no comparative study of the two methods. A total of 100 patients with a mean age of 31.3 years (16 to 49) and with a symptomatic lesion of the articular cartilage in the knee which was suitable for cartilage repair was randomised to undergo either ACI or mosaicplasty; 58 patients had ACI and 42 mosaicplasty. Most lesions were post-traumatic and the mean size of the defect was 4.66 cm2. The mean duration of symptoms was 7.2 years and the mean number of previous operations, excluding arthroscopy, was 1.5. The mean follow-up was 19 months (12 to 26). Functional assessment using the modified Cincinatti and Stanmore scores and objective clinical assessment showed that 88% had excellent or good results after ACI compared with 69% after mosaicplasty. Arthroscopy at one year demonstrated excellent or good repairs in 82% after ACI and in 34% after mosaicplasty. All five patellar mosaicplasties failed. Our prospective, randomised, clinical trial has shown significant superiority of ACI over mosaicplasty for the repair of articular defects in the knee. The results for ACI are comparable with those in other studies, but those for mosaicplasty suggest that its continued use is of dubious value.     

四种自体植入物作月骨替代物的对比实验研究

目的 对比研究四种自体植入物置入动物关节腔后的组织形态学变化,为治疗Kienbock病提供可行的月骨替代物。方法 选新西兰白兔60只,按手术前后随机分为A组(骨膜组)、B组(复合体组)、C组(BMP-松质骨粒复合体组)和D组(对照组),每组15只。将四种植入物分别植入兔关节腔内,术后3、6、12、16和24周时取材,组织学观察骨形成并测量骨密度值(bone mineral density,BMD)。结果 A组、B组均有骨和软骨形成,后者尤为明显;C组仅有骨形成;D组呈玻璃样变性,无骨形成。标本的 BMD值经统计学方差分析,A组、B组和D组间有非常明显的差别(P<0.01),B组与C组间无明显差别(P>0.05)。结论 BMP-松质骨粒复合体组骨形成较强;复合体组在骨膜、松质骨匀浆中多种骨形成诱导因子作用下可形成大量骨和软骨,两种自体植入物可用作月骨替代物。     

Clinical outcomes of autogenous cancellous bone grafts obtained through the portal for tibial nailing

BackgroundThe purpose of this study is to introduce and review the clinical outcomes of a new technique for harvesting autogenous cancellous bone grafts in association with tibial intramedullary (IM) nailing.Materials and methodsWe retrospectively reviewed 21 patients who received autogenous cancellous bone grafts obtained from the entry portal of a tibial IM nail for fracture gaps, malalignment or nonunion in the lower extremities. All patients were scheduled to receive IM nailing or had already received IM nailing for the fixation of an ipsilateral tibia shaft fracture. A total of 33 patients who received only tibial IM nailing were selected as a control group. Through the follow-up, postoperative complications related to the bone harvest were monitored. Further by taking serial X-rays, radiographic changes of the donor site and the knee joint were closely observed. Knee pain (visual analogue scale (VAS)) and function (Lysholm knee score) were compared between the study group and the control group.ResultsAt the last follow-up, the average VAS in the study group was 1.28 (0–5), which was not significantly different from the control group (VAS: 1.36, range 0–7) (P = 0.985). The range of motion of the knee joint was similar in both groups, averaging 130.23° (range: 115–135°) and 131.36° (range: 115–135°), respectively. There was no significant difference in the Lysholm knee score between the study and control groups (P = 0.610). All patients exhibited complete fracture healing at an average of 6 months and no complications associated with the bone donor site were observed.ConclusionsBy using the new technique, autogenous cancellous bone grafting can be performed conveniently and safely to treat fracture gaps, malalignment or nonunion in the lower extremities without additional morbidity at the donor site.     

大鼠膝关节不稳定骨性关节炎软骨与软骨下骨组织微观结构的变化

[目的]观察大鼠膝关节经前交叉韧带切断术(anterior cruciate ligament transection,ACLT)造成关节不稳定情况下,其关节软骨与软骨下骨骨组织微结构的变化.[方法] 20只3个月龄雄性SD大鼠按体重随机分为对照组与实验组,每组10只动物.实验组切断右膝关节前交叉韧带,对照组只暴露前交叉韧带而不切断,术后12周处死所有动物并取材.取右肢股骨远端膝关节于70％酒精固定后脱钙6周,石蜡包埋切片,经HE染色及Masson染色,普通光学显微镜观察摄片,采用图像分析系统做定量分析;取右肢胫骨膝关节于70％酒精固定后不脱钙做硬组织包埋切片,行Van Kossa染色后,定量分析软骨下骨组织微观结构变化.[结果]术后12周后大体观察发现,实验组关节面较对照组明显失去光泽,呈颗粒感,部分软骨面破溃,关节面周围可见骨赘形成;实验组关节软骨HE及Masson染色着色不均,软骨细胞排列紊乱,且实验组Mankin评分结果显著高于对照组,差异具有统计学意义(P＜0.05);实验组软骨下骨组织微结构较对照组改变明显,差异具有统计学意义(P＜0.05).[结论]ACLT术导致膝关节不稳定,在此情况下对大鼠膝关节软骨形态及软骨下骨组织微结构造成显著破坏,若不能及时采取干预措施,将加速膝关节功能退变进程.     

Effects of estrogen deficiency and low bone mineral density on healthy knee cartilage in rabbits

The purpose of this study was to compare the effects of estrogen deficiency and bone mass loss on normal knee cartilage in mature rabbits. Bilateral ovariectomy (OVX) was performed in 13 rabbits, 6 of which also received systemic glucocorticoid for 4 weeks. Seven additional healthy rabbits were used as controls. Bone mineral density (BMD) was measured by dual X‐ray absorptiometry in lumbar spine, knee, and subchondral bone of the knee at baseline and 22 weeks after OVX. After sacrifice, the knees were dissected, macroscopy was assessed, and histological cartilage abnormalities were evaluated according to the Mankin score. Correlations of Mankin with BMD at different regions were also performed. When compared to baseline, differences in BMD were only found in spine and knee of the animals receiving glucocorticoids. All the animals subjected to OVX had a significantly higher Mankin score than controls. Mankin was upper in OVX animals receiving glucocorticoids, but differences were not significant. The Mankin score was inversely related with BMD in lumbar spine (r = ?0.67; p < 0.01). Although low bone mineral density contributes to the minor osteoarthritic alterations observed in our model, estrogen deficiency itself seems to act directly to induce the main pathogenic effects in healthy cartilage of the rabbit. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 28:812–818, 2010     

Differentiation of the Osteochondrogenic Cells of the Periosteum in Chondrotrophic Environment

The behaviour of the cells in free periosteal grafts was studied in growing rabbits in three chondrotrophic recipient milieus: costal cartilage, ear cartilage and synovial fluid of the knee joint. The periosteal grafts first formed cartilage, which was then quite rapidly transformed into bone on the costal cartilage, quite slowly and in smaller amounts in the ear cartilage, whereas no bone was found in the cartilaginous loose bodies formed in the knee joint. In bone formation vascularization plays a major role, but other factors are also involved.     

Bisphosphonates in the Treatment of Thalassemia-Induced Osteoporosis

The aim of our randomized, placebo-controlled study was to investigate the effects of 2 years’ daily oral administration of alendronate or intramuscular administration of clodronate every 10 days, on bone remodeling parameters and bone mineral density (BMD), safety and tolerability in a group of osteoporotic thalassemic patients. Twenty-five young patients (mean age 26.6 ± 7.1 years) with beta-thalassemia major were randomly divided to receive placebo or 100 mg of clodronate intramuscularly every 10 days or 10 mg of alendronate per os daily. All patients took 500 mg of elemental calcium and 400 IU cholecalciferol in the evening at meal time. After 2 years, pyridinium crosslinks, which are bone resorption markers, did not differ significantly from baseline values in the placebo group, whereas they had decreased significantly in the clodronate and alendronate groups. Osteocalcin, a bone formation marker, did not change significantly in the placebo group, whereas it decreased slightly, but not significantly, in the clodronate and alendronate groups after 12 and 24 months. At the end of the study, the lumbar spine BMD had decreased significantly in the placebo group; it did not change significantly in the clodronate group; in the alendronate group it had increased but not significantly, whereas the increase was significant with respect to the placebo group. Femoral neck BMD decreased significantly in the placebo group; it did not change significantly in the clodronate group, but increased significantly in the alendronate group. No relevant side effects were recorded during our study. In conclusion, in patients with thalassemia-induced osteoporosis, the daily administration of alendronate significantly increases BMD, the most important predictor of the risk of fracture at several sites. Clodronate treatment at our dosage is ineffective in this pathology in spite of the good compliance of patients. Received: 13 August 2001 / Accepted: 19 February 2002     

The effect of alendronate on bone mineral density in the distal part of the femur and proximal part of the tibia after total knee arthroplasty

BACKGROUND: Bone mineral density around the knee is related to the mechanical properties of bone. Alendronate has been shown to be effective for the treatment of osteoporosis and for reducing the rate of osteoporotic fractures. The purpose of the present study was to investigate the effect of alendronate on bone mineral density in the distal part of the femur and proximal part of the tibia after total knee arthroplasty in women. METHODS: Ninety-six women with an average age of seventy years who were undergoing total knee arthroplasty were randomly divided into two groups. Patients in the study group received oral alendronate at a dose of 10 mg/day for six months, whereas patients in the control group did not. The bone mineral density in the distal part of the femur and proximal part of the tibia was determined preoperatively and at six and twelve months postoperatively. RESULTS: In the control group, the bone mineral density showed significant decreases of 13.8% (p < 0.001) and 7.8% (p = 0.003) in the distal part of the femur and of 6.5% (p = 0.002) and 3.6% (p = 0.141) in the proximal part of the tibia at six and twelve months, respectively. In the study group, however, the bone mineral density showed significant increases of 10.0% (p = 0.010) and 1.9% (p = 0.049) in the distal part of the femur and of 9.4% (p < 0.001) and 5.4% (p = 0.032) in the proximal part of the tibia at six and twelve months, respectively. The overall differences in bone mineral density between the study and control groups were significant (p = 0.011 for the proximal part of the tibia, and p = 0.033 for the distal part of the femur). CONCLUSIONS: We found significant postoperative decreases in bone mineral density in the distal part of the femur and proximal part of the tibia in women who had undergone total knee arthroplasty. Oral administration of alendronate for six months postoperatively significantly improved the bone mineral density. While the clinical benefits of alendronate after total knee arthroplasty remain unproven and the duration of follow-up in the present study was quite short, the improvement in bone mineral density may have a clinically important effect on prosthetic fixation and the rate of periprosthetic fractures after total knee arthroplasty.     

Enhancement of Crude Bone Morphogenetic Protein-Induced New Bone Formation and Normalization of Endochondral Ossification by Bisphosphonate Treatment in Osteoprotegerin-Deficient Mice

Osteoprotegerin (OPG) is a novel secreted member of the tumor necrosis factor receptor family which plays a crucial role in negative regulation of osteoclastic bone resorption. We investigated both the quantity and quality of heterotopic new bone induced by crude bone morphogenetic protein (BMP) as a means of examining bone metabolism by bisphosphonate administration in OPG^−/− mice. Four weeks after implantation of crude BMP, the volume of heterotopic new bone in OPG^−/− mice without alendronate was significantly less than in wild-type (WT) mice. Alendronate treatment of OPG^−/− mice resulted in enhancement of the volume of heterotopic new bone. Histological findings revealed that WT mice showed normal bone formation with persistent cartilage that was interspersed with islands of bone. In contrast, the cartilage was replaced by trabecular bone and bone marrow adipocytes in OPG^−/− mice without alendronate. However, some cartilage was still present in OPG^−/− mice with alendronate compared to those without alendronate. All bone formation-related parameters and bone resorption-related parameters were significantly lower in OPG^−/− mice with alendronate than in those without alendronate. These findings suggest that in stimulated osteoclastogenesis without OPG, osteoinductive activity induced by crude BMP is inhibited and endochondral ossification induced by crude BMP is accelerated. On the other hand, alendronate treatment of OPG^−/− mice caused osteoinductive activity induced by crude BMP to increase and endochondral ossification induced by crude BMP to be decelerated. In conclusion, inhibition of stimulated osteoclastogenesis results in the enhancement of new bone formation and normalization of endochondral ossification.     

Autologous chondrocyte transplantation in the ankle joint. Rational or irrational?

Ankle sprains are one the most common injuries of the lower limb. Fractures, ligamentous lesions, and cartilaginous damage are often associated. Nevertheless the injury is often misjudged and concomitant chondral lesions are assessed late. In the case of a symptomatic osteocartilaginous lesion of the talus, which can be illustrated by MRI or X-ray, operative intervention is indicated.Methods such as microfracturing, mosaicplasty, and autologous chondrocyte transplantation (ACT) are in clinical use. The latter is well known and being established as the treatment of choice for large cartilage defects in the knee. Due to the good results in the knee and the technological improvements (three-dimensional tissue constructs seeded with autologous chondrocytes) this method is being increasingly applied for cartilage lesions of the talus.In contrast to the mosaicplasty donor site morbidity is low and the size of the defect is not a limiting factor. The current studies about ACT of the talus show a stable repair of the defect with mostly hyaline-like cartilage and high patient satisfaction. Therefore, the procedure can be recommended for lesions>1 cm2. Concomitant treatment of posttraumatic deformities (malalignment), ligamentous instabilities, and especially the reconstruction of bony defects are compulsory.     

Donor’s site evaluation after restoration with autografts or synthetic plugs in rabbits

AIM: To investigate donor site's area histological and immunohistochemical knee cartilage appearances after resurfacing iatrogenic defects with biosynthetic plugs orautografts. METHODS: Thirty New Zealand White rabbits were used in this study. A full-thickness cylindrical defect of 4.5 mm(diameter) × 7 mm(depth) was created with a hand drill in the femoral groove of every animal. In Group A(n = 10) the defect of the donor site was re-paired with a biosynthetic osteochondral plug, in Group B(n = 10) with an osteochondral autograft, while in Group C(control group of 10) rabbits were left untreated. RESULTS: Twenty-four weeks postoperatively, smooth articular cartilage was found macroscopically in some trocleas' surfaces; in all others, an articular surface with discontinuities was observed. Twenty-eight out of 30 animals were found with predominantly viable chondrocytes leaving the remaining two-which were found only in the control group- with partially viable chondrocytes. However, histology revealed many statistical differences between the groups as far as the International Cartilage Repair Society(ICRS) categories are concerned. Immunofluoresence also revealed the presence of collagen Ⅱ in all specimens of Group B, whereas in Group A collagen Ⅱ was found in less specimens. In Group C collagen Ⅱwas not found. CONCLUSION: The matrix, cell distribution, subchondral bone and cartilage mineralization ICRS categories showed statistically differences between the three groups. Group A was second, while group B received the best scores; the control group got the worst ICRS scores in these categories. So, the donor site area, when repairing osteochondral lesions with autografting systems, is better amended with osteochondral autograft rather than bone graft substitute implant.     

Inhibition of sclerostin by monoclonal antibody enhances bone healing and improves bone density and strength of nonfractured bones

Therapeutic enhancement of fracture healing would help to prevent the occurrence of orthopedic complications such as nonunion and revision surgery. Sclerostin is a negative regulator of bone formation, and treatment with a sclerostin monoclonal antibody (Scl‐Ab) results in increased bone formation and bone mass in animal models. Our objective was to investigate the effects of systemic administration of Scl‐Ab in two models of fracture healing. In both a closed femoral fracture model in rats and a fibular osteotomy model in cynomolgus monkeys, Scl‐Ab significantly increased bone mass and bone strength at the site of fracture. After 10 weeks of healing in nonhuman primates, the fractures in the Scl‐Ab group had less callus cartilage and smaller fracture gaps containing more bone and less fibrovascular tissue. These improvements at the fracture site corresponded with improvements in bone formation, bone mass, and bone strength at nonfractured cortical and trabecular sites in both studies. Thus the potent anabolic activity of Scl‐Ab throughout the skeleton also was associated with an anabolic effect at the site of fracture. These results support the potential for systemic Scl‐Ab administration to enhance fracture healing in patients. © 2011 American Society for Bone and Mineral Research.