Porous Tantalum Rod Research Articles

Progress in the Application of Porous Tantalum Metal in Hip Joint Surgery.

Porous tantalum metal is a new orthopedic implant material made of tantalum metal that has been processed by porous treatment. This material has various advantages, including high hardness, good ductility, good biocompatibility, and strong bone integration ability. Porous tantalum metal has performed well in clinical application, demonstrating excellent medium- to long-term curative effects. The use of implant products made of porous tantalum metal, such as porous tantalum rods, porous tantalum hip prostheses, and porous tantalum augments (MAs), is gradually increasing in the clinical application of hip surgery, and these products have achieved excellent therapeutic effects in the middle and late stages of various hip diseases. In recent years, the combined application of porous tantalum metal and three-dimenional (3D) printing technology to create personalized 3D-printed porous tantalum metal has led to new development directions for the treatment of complex hip joint surgical diseases. This review presents a summary of the application of porous tantalum metal in hip surgery in recent years, including clinical treatment effects and existing problems. In addition, the prospect of progress in this field is promoted.

Partial femoral head replacement: a new innovative hip-preserving approach for treating osteonecrosis of the femoral head and its finite element analysis.

Purpose: Controversy remains regarding the optimal treatment for stage III Osteonecrosis of the femoral head (ONFH). This study presents, for the first time, the precise treatment of stage III ONFH using the "substitute the beam for a pillar" technique and performs a comparative finite element analysis with other hip-preserving procedures. Methods: A formalin-preserved femur of male cadavers was selected to obtain the CT scan data of femur. The proximal femur model was reconstructed and assembled using Mimics 20.0, Geomagic, and UG-NX 12.0 software with four different implant types: simple core decompression, fibula implantation, porous tantalum rod implantation, and partial replacement prosthesis. The finite element simulations were conducted to simulate the normal walking gait, and the stress distribution and displacement data of the femur and the implant model were obtained. Results: The peak von Mises stress of the femoral head and proximal femur in the partial replacement of the femoral head (PRFH) group were 22.8MPa and 37.4MPa, respectively, which were 3.1%-38.6% and 12.8%-37.4% lower than those of the other three surgical methods. Conclusion: The PRFH group exhibits better mechanical performance, reducing stress and displacement in the ONFH area, thus maintaining femoral head stability. Among the four hip-preserving approaches, from a biomechanical perspective, PRFH offers a new option for treating ONFH.

Total hip replacement after prior of the core decompression of the femoral head: efficacy and complications

Relevance. A history of core decompression using porous tantalum rods has a negative impact on the course of total hip arthroplasty surgery, the postoperative period and the frequency and nature of postoperative complications. Opinions are contradictory with regard to the effect of other techniques of necrosis decompression on total hip arthroplasty.Purpose of the study: evaluation of the effect of core decompression of the femoral head on the intraand postoperative parameters of total hip arthroplasty surgery.Object and methods. The study included 44 patients with osteonecrosis of the femoral head who underwent total hip arthroplasty. The first group consisted of 30 patients with osteonecrosis of the femoral head (ARCO grade II-IV) who had no previous hip surgery – primary total hip arthroplasty. The second group included 14 patients with osteonecrosis who had undergone the core decompression on the same joint (secondary total hip arthroplasty) 6–24 months earlier in stage II of the disease. The duration of surgery, blood loss volume, complications in the postoperative period, pain syndrome dynamics and hip joint function were assessed.Results. Comparative analysis showed the absence of significant technical intraoperative complications in total hip arthroplasty: duration of operations in group I – 85 ± 25 minutes, in group II – 80 ± 20 minutes, that is, almost identical; volume of intraoperative blood loss: 300 ± 100 ml in both groups. Survival rate of the hip replacement was 100 % in both groups. Superficial inflammation of the operating wound was diagnosed in 3.3 % of group I patients and in 7.1 % of group II patients (%). Dislocation of the hip replacement was observed in one patient in Group I (primary total hip arthroplasty). Twelve months after THA, osteolysis around the hip replacement element was detected by X-ray in 6.7 % of group I patients.Conclusion. Total hip arthroplasty in patients with a history of the core decompression of the femoral head is not accompanied by intraoperative technical difficulties and is a relatively safe surgical intervention. Prior core decompression is not an additional risk factor for intraand postoperative complications of total hip arthroplasty.

Hip Resurfacing Arthroplasty after Failure of Tantalum Rod Insertion in Patients with Osteonecrosis of the Femoral Head.

The purpose of this study was to examine the clinical outcomes and efficacy of hip resurfacing arthroplasty (HRA) in patients with osteonecrosis of the femoral head after the failure of porous tantalum rod insertion without rod removal. Conversion to hip resurfacing arthroplasty was performed in 10 patients (11 hips) with a mean period of 14.9 months after the primary surgery. The mean follow-up period was 73.7 months. Analysis of pre and postoperative range of motion (ROM), University of California at Los Angeles (UCLA) activity score, modified Harris hip score, and visual analog scale (VAS) pain score was performed. Radiographic analysis of component loosening and osteolysis was performed. The postoperative ROM showed significant improvement (P<0.05), excluding flexion contracture. The modified Harris hip score showed improvement from 65.82 to 96.18, the UCLA score showed improvement from 4.18 to 8.00, and the VAS pain score was reduced from 6.09 to 1.80. All scores showed statistically significant improvement (P<0.05). No component loosening or osteolysis was detected by radiographic analysis. Satisfactory results were obtained from conversion hip resurfacing arthroplasty after failure of porous tantalum rod insertion without rod removal. The findings of this study demonstrate the advantages of HRA, including no risk of trochanteric fracture and no bone loss around the tantalum rod. In addition, the remaining porous tantalum rod provided mechanical support, which reduced the potential risk of femoral neck fracture or loosening. This technique can be regarded as a favorable treatment option.

Analysis of peripheral bone reconstruction after the failure of hip osteonecrosis treatment with porous tantalum rod implantation.

Failure of porous tantalum rod (PTR) implantation in treating early osteonecrosis of femoral head (ONFH) has been frequently reported, but the underlying mechanism remains uncertain, which raised the concern of its efficacy. The study aimed to discuss the underlying mechanism from the perspectives of bone reconstruction and pathological changes. Five patients with PTR implantation experienced total hip arthroplasty (THA) due to recurrent pain, whose femoral heads were collected as "tantalum group." Normal (fracture) and necrotic femoral heads were respectively collected (both n = 5) after THA. The bone quality and structure, biomechanical properties, and histopathological features were analyzed by micro-CT scanning, mechanical measurement, and histological examination. Both the tantalum group and necrotic group had significantly poorer bone quantity and quality than the normal group. Three-dimensional imaging reconstruction showed that the trabeculae of the tantalum group were poorest in quality. Significant differences in terms of bone quality, structure, and biomechanical properties were present between the inside and outside regions around PTR, which revealed abnormal bone reconstruction. Biomechanical analysis revealed inferior properties in the tantalum group and necrosis group. H&E staining demonstrated neutrophil infiltration among the peripheral trabeculae around PTR, and the inflammation cells were significantly more abundant than that in the normal and necrosis groups. Abnormal bone reconstruction around PTR was an important cause for failure of PTR implantation in the treatment of ONFH, which was related to biomechanical stress distribution and chronic inflammation infiltration. Insufficient biomechanical support and inflammatory trabeculae edema might account for the recurrent pain.

Dynamic Observation of Vascular Regeneration in Femoral Head Necrosis: a 5-Year Follow-Up Case Report

Femoral Head Necrosis (FHN) is an invasive hip disease of skeletal system, which associated with vascular dysfunction. Therefore, vessels regeneration and follow the posterolateral direction are regarded as a potential therapy target for FHN. We report a case of FHN that was treated by successful regeneration of the internal circumflex femoral artery via targeted Lipoaspirate (LPS) infusion and biomechanical support. A 35-year-old man with FHN involved. LPS isolated from the abdominal subcutaneous fat and infuse into the internal circumflex artery approximately seven times at every 1.5 months in both femoral heads. Besides, the porous tantalum rod was grafted after the first LPS infusion on each side. After the 5-year follow-up study, the primary outcomes showed obvious improvement in the number, distribution, and diameter of blood vessels in the ischemic area. In addition, the patient was now able to perform the daily activities; the congestive area increased from 73.4% to 94.2% on the left side and from 0% to 71.8% on the right side. The Harris Hip Score improved from 22 to 91. Multiple LPS infusions via the internal circumflex femoral artery combined with porous tantalum rod grafting offers an alternative treatment option for FHN.

Porous tantalum implant for treatment of early-stage osteonecrosis of the femoral head: a minimum 5-year follow-up study

BackgroundTo evaluate the survival rate of porous tantalum rod implantation in the treatment of osteonecrosis of the femoral head (ONFH), evaluate its clinical effect and imaging results.MethodsFrom January 2008 to December 2013, porous tantalum rod implantation for ONFH was performed in two institutions. Statistical analysis of operation data, including operation time, blood loss and blood transfusion were recorded.Results52 hips received complete follow-up, the average follow-up time was 85.7 months (60–132 months). 24 hips turned to THA at the end of follow-up (46.2%), the average time was 44.3 ± 32.8 months, and the average Harris hip score before THA was 57.1 ± 7.6. Cox proportional-hazards model revealed that Association Research Circulation Osseous (ARCO) stage (P = 0.017), bone marrow edema (P = 0.006) and age > 40 years (P = 0.043) were independent risk factors for conversion to THA.ConclusionARCO stage, age and bone marrow edema were risk factors for the failure of porous tantalum rod implantation to convert to THA.

Application of Porous Tantalum in Osteonecrosis of the Femoral Head

Biomaterials were used in the repair and treatment of avascular necrosis of femoral head (ANFH), which has made a high clinical and social value for preserving the patient’s own hip joint function. Among them, the porous tantalum (pTa) rod support technology is a minimally invasive surgical treatment for ANFH that has been applied in recent years. In this study, a pTa rod combined with vascularized iliac bone flap transplantation was used to treat ANFH. In vitro studies have shown, pTa rod implants are very close to natural bone tissue in structure and physiological and mechanical properties, and have good tissue compatibility and safety. Clinical studies have found that the combination of pTa rod and vascularized iliac bone flap transplantation can improve the hip joint function of patients with ANFH in the middle and late stages, and effectively prevent the exacerbation of necrosis, providing a new treatment for hip-preserving treatment of patients with ANFH method.

Efficacy of tantalum rod insertion for preventing femoral head collapse in osteonecrosis in a paediatric population: a pilot study.

ABSTRACTFemoral head osteonecrosis in the paediatric population is difficult to treat, with the primary goals of management being prevention of subchondral collapse and the avoidance of early total hip replacement. This study aims to describe the use of a porous tantalum rod implant to provide mechanical support in preventing femoral head collapse in a paediatric population. A retrospective chart-based analysis of patients with osteonecrosis of the hip was performed at our institution to identify those who had undergone tantalum rod insertion. A total of 10 patients (fives males and five females, median age 12.5 years, 9–18) had tantalum rods implanted between December 2013 and February 2018. One patient was excluded due to follow-up at a different institution. The radiographic degree of osteonecrosis was characterized according to the Ficat classification and the Kerboul angle. Radiographic assessment of pre- and post-operative plain films was performed. The outcome measures were Tonnis grade and percentage collapse of the femoral head. Nine patients with a mean follow-up time of 18.4 months were included in the analysis. There was no significant increase in the femoral head collapse percentage post tantalum rod insertion compared to pre-operatively (P = 0.63). There was a significant increase in the Tonnis grade post-operatively (P < 0.05), with sub-group analysis showing minimal increase in Ficat Stage 1 patients. This study is the first to examine the role of tantalum rod insertion in preventing femoral head collapse in a paediatric population, with results suggesting potential benefit in a subset of patients.

Efficacy and Safety of Stem Cell Combination Therapy for Osteonecrosis of the Femoral Head: A Systematic Review and Meta-Analysis.

Background The treatment results of core decompression (CD) and biomechanical support are not always satisfactory in osteonecrosis of the femoral head (ONFH). Stem cell therapy has been incorporated into traditional treatment in order to promote bone regeneration. The efficacy and safety of stem cell therapy combined with CD or biomechanical support on advanced and long-term patients with ONFH were unknown. The aim of this study was to assess whether stem cell combination therapy is superior to single CD or porous tantalum rod implantation treatment in ONFH. Methods A systematic search of the literature was performed to evaluate all included randomized controlled trials (RCTs) on stem cell combination therapy for patients with ONFH in PubMed, Cochrane Library, Web of Science, and Embase sites. We assessed the quality and risk of bias for the included studies. And the outcomes of Harris hip score (HHS), visual analogue scale (VAS), and adverse events were statistically analyzed. Results We included 10 randomized controlled trials, containing a total of 498 patients with 719 hips. Stem cell therapy combined with CD versus CD alone for HHS of ONFH was different (MD = 8.87, 95% CI = [5.53, 12.22], P < 0.00001). The combination of stem cell therapy and CD can effectively improve HHS. Similarly, the VAS of the stem cell combination therapy group also differed compared with the control group (MD = −14.07, 95% CI = [−18.32, −9.82], P < 0.00001). The result showed that stem cell combination therapy can relieve the pain of patients with ONFH. There was no significant difference in adverse response outcome events between the combination therapy group and the control group (RR = 1.57, 95% CI = [0.62, 3.97], P = 0.34). Conclusions Stem cell therapy combined with core decompression is an effective and feasible method with few complications in the clinical treatment of early-stage ONFH. Even in the combination of porous tantalum rod implantation and peripheral blood stem cells, stem cell combination therapy is superior to single biomechanical support treatment. But high-quality, large-sample, multicenter, and long-term follow-up RCTs are still needed to corroborate the efficacy and safety of stem cell combination therapy in ONFH treatment.

Comparison of cell therapy and other novel adjunctive therapies combined with core decompression for the treatment of osteonecrosis of the femoral head

AimsThe value of core decompression (CD) in the treatment of osteonecrosis of the femoral head (ONFH) remains controversial. We conducted a systematic review and meta-analysis to evaluate whether CD combined with other treatments could improve the clinical and radiological outcomes of ONFH patients compared with CD alone.MethodsWe searched the PubMed, Embase, Web of Science, and Cochrane Library databases until June 2020. All randomized controlled trials (RCTs) and clinical controlled trials (CCTs) comparing CD alone and CD combined with other measures (CD + cell therapy, CD + bone grafting, CD + porous tantalum rod, etc.) for the treatment of ONFH were considered eligible for inclusion. The primary outcomes of interest were Harris Hip Score (HHS), ONFH stage progression, structural failure (collapse) of the femoral head, and conversion to total hip arthroplasty (THA). The pooled data were analyzed using Review Manager 5.3 software.ResultsA total of 20 studies with 2,123 hips were included (CD alone = 768, CD combined with other treatments = 1,355). The combination of CD with other therapeutic interventions resulted in a higher HHS (mean difference (MD) = 6.46, 95% confidence interval (CI) = 2.10 to 10.83, p = 0.004) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score (MD = −10.92, 95% CI = -21.41 to -4.03, p = 0.040) and a lower visual analogue scale (VAS) score (MD = −0.99, 95% CI = -1.56 to -0.42, p < 0.001) than CD alone. For the rates of disease stage progression, 91 (20%) progressed in the intervention group compared to 146 (36%) in the control group (odds ratio (OR) = 0.32, 95% CI = 0.16 to 0.64, p = 0.001). In addition, the intervention group had a more significant advantage in delaying femoral head progression to the collapsed stage (OR = 0.32, 95% CI = 0.17 to 0.61, p < 0.001) and reducing the odds of conversion to THA (OR = 0.35, 95% CI = 0.23 to 0.55, p < 0.001) compared to the control group. There were no serious adverse events in either group. Subgroup analysis showed that the addition of cell therapy significantly improved clinical and radiological outcomes compared to CD alone, and this approach appeared to be more effective than other therapies, particularly in precollapse (stage I to II) ONFH patients.ConclusionThere was marked heterogeneity in the studies. There is a trend towards improved clinical outcomes with the addition of stem cell therapy to CD.Cite this article: Bone Joint Res 2021;10(7):445–458.

Comparative analysis and study on the rehabilitation of cruciate ligaments before and after treatment with nano-biomaterials

This paper uses porous silicon carbide as a stent, and applies chemical vapour deposition technology to prepare a new type of porous tantalum metal material and conduct preliminary biological evaluation. An experimental study on the repair of anterior and posterior cruciate ligament composite of porous tantalum metal material is carried out, and it is used in clinical practice. To treat patients with anterior cruciate ligament injury, comprehensively evaluate the biological characteristics of new porous tantalum metal and its clinical effect in the treatment of anteroposterior cruciate ligament injury, and apply a new porous tantalum rod combined with anterior cruciate ligament combined with vascular pedicle iliac flap transfer. Young and strong patients with anterior and posterior cruciate ligament injury were treated with ligament-preserving surgery. Under the condition that it was clear that bone marrow stromal cells had a bone-promoting effect, and porous tantalum metal rods could induce bone growth and biomechanical support, and vascularised iliac bone flap metastasis was studied. Young and middle-aged patients with anterior and posterior cruciate ligament injuries were treated with satisfactory results. The research results found that a new porous tantalum rod combined with anterior and posterior cruciate ligament combined with vascular pedicle iliac flap transfer effectively removed the femoral head. Internal necrosis bone promotes the new femoral head bone regeneration and provides a reliable blood supply and biomechanical support. Prevention of further collapse occurred, to assist front and rear cruciate ligament rehabilitation, and did not increase surgical complications.

Porous tantalum rod implantation is associated with low survival rates in patients with type C2 osteonecrosis of the femoral head but has no effect on the clinical outcome of conversion total hip arthroplasty: a retrospective study with an average 8-year follow-up

BackgroundOur study aimed to investigate the clinical outcomes and survival rates following porous tantalum rod surgery (PTRS) and conversion total hip arthroplasty (THA) subsequent to failed PTRS.MethodsA total of 38 subjects (40 hips) with osteonecrosis of the femoral head (ONFH) were included in this retrospective study between January 2008 and December 2011. All subjects were evaluated before surgery by using the Association Research Circulation Osseous (ARCO) classification system, the Japan Investigation Committee (JIC) classification and the Harris hip score (HHS). The endpoint of this study was set as final follow-up (including the survival time of PTRS and conversion THA). The rates of radiological progression were also evaluated. Patients who received conversion THA were further followed and compared to a control group of 58 patients with ONFH who underwent primary THA.ResultsThe mean follow-up time was 120.7 ± 9.2 (range, 104–143) months, and the overall survival rate was 75% at 96 months (ARCO stage II: 81.5%; stage III: 38.5%; JIC type C1: 83.3%; C2: 30%). The HHS before surgery was 59 (55–61), in contrast to 94 (91–96) at 96 months follow-up (P < 0.01). HHS in stage III show a significant poorer result compared to stage II at 24 months. HHS in Type C2 group show no significant difference compared to HHS before surgery at 24 and 60 months follow up (P = 0.91, P = 0.30). Twelve hips requiring secondary THA were followed for 66.9 ± 31.7 months, and control hips that underwent primary THA was followed for 75.4 ± 14.9 months. The HHS in the conversion group was 89 (86–93) and that in the primary THA group was 92 (79–95, P = 0.09) at the 5-year follow-up.ConclusionIn the mid-term follow-up, porous tantalum implants showed an encouraging survival rate in symptomatic patients in early stages (ARCO stage II) or with limited necrotic lesions (JIC type C1). In addition, our results did not demonstrated any difference between primary THA and conversion THA.

Three-Dimensional, MultiScale, and Interconnected Trabecular Bone Mimic Porous Tantalum Scaffold for Bone Tissue Engineering

To investigate the biocompatibility and bone ingrowth properties of a novel trabecular bone mimic porous tantalum scaffold which holds potential for bone tissue engineering, a novel three-dimensional, multiscale interconnected porous tantalum scaffold was designed and manufactured. The morphology of the novel scaffold was observed with the use of scanning electron microscopy (SEM) and industrial computerized tomography. Mesenchymal stem cells (MSCs) were cultured with novel porous tantalum powder, SEM was carried out for the observation of cell morphology and adhesion, and cytotoxicity was evaluated by the MTT assay. Canine femoral shaft bone defect models were established, and novel porous tantalum rods were used to repair the bone defect. Repair effects and bone integration were evaluated by hard tissue slice examination and push-out tests at the indicated time. We found that the novel porous tantalum scaffold is a trabecular bone mimic, having the characteristics of being three-dimensional, multiscaled, and interconnected. The MSCs adhered to the surface of tantalum and proliferated with time, the tantalum extract did not have a cytotoxic effect on MSCs. In the bone defect model, porous tantalum rods integrated tightly with the host bone, and new bone formation was found on the scaffold-host bone interface both 3 and 6 months after the implantation. Favorable bone ingrowth was observed in the center of the tantalum rod. The push-out test showed that the strength needed to push out the tantalum rod is comparable for both 3 and 6 months when compared with the normal femoral shaft bone tissue. These findings suggested that the novel trabecular bone mimic porous tantalum scaffold is biocompatible and osteoinductive, which holds potential for bone tissue engineering application.

The Comparative Analysis of Antegrade Versus Retrograde Approach for a Failed Porous Tantalum Rod Removal During Conversion to Total Hip Arthroplasty.

BackgroundThe failure of porous tantalum rods applied to patients with osteonecrosis of the femoral head (ONFH) has been increasingly reported during the last few years. Very few studies have reported methods for implant removal. This study aimed at comparing 2 procedures used for the removal of a failed tantalum rod during conversion to total hip arthroplasty (THA).Material/MethodsA total of 65 patients (65 hips), who underwent THA after failed implantation of a tantalum rod between June 2007 and December 2016, were retrospectively evaluated. These patients were classified into 2 groups depending on whether the antegrade approach (removal of the tantalum rod from the tip to the butt at the lateral femoral cortex, n=27) or retrograde approach (removal of the tantalum rod from the butt at the lateral femoral cortex to the proximal tip, n=38) was used for rod extraction. These 2 groups were compared for incision length, operation time, blood loss, fracture, tantalum debris, Harris hip scores, and the presence of osteolysis and/or radiolucency.ResultsThese 2 groups did not present any significant differences in terms of Harris hip score and incision length. However, the operation time (P=0.000), blood loss (P=0.000), amount of tantalum debris (P=0.000), and presence of radiolucency (P=0.046) were greater for the retrograde approach than for the antegrade approach.ConclusionsThe risk of conversion to THA following failed tantalum rod implantation is high. In such cases, the antegrade procedure was found to be a simple and efficient method for removing the trabecular metal rod with the use of a trephine.

Comparison of core decompression and porous tantalum rod implantation with conservative treatment for avascular necrosis of the femoral head: A minimum 18 month follow-up study.

Porous tantalum rod implantation is a novel surgical method that is used to treat avascular necrosis (AVN) of the femoral head (hip). In the present study, the results of core decompression and tantalum rod implantation were compared with non-surgical treatment for AVN, and the survivorship of the femoral head was evaluated. In total, 60 patients with AVN femoral head were recruited and analysed. Non-surgical treatment was selected by 30 patients (41 hips), 7 with a Ficat score of I and 23 with a score of II. Non-surgical treatment included celecoxib, salvia miltiorrhiza and tetramethylypyrazine and a reduction in weight-bearing activities. Surgical treatment and porous tantalum rod implantation were selected by 30 patients (41 hips), 10 with a Ficat score of I and 20 with a score of II. After follow-up (average: 33.5 months), patients were evaluated by assessing post-operative complications, radiology, hip survivorship and Harris hip score. In the surgical group, pre-operative symptoms were significantly alleviated. No complications, including infection, delayed healing or fractures were reported. Final follow-up rates of femoral head survivorship were 4.9% in the non-surgical group and 36.7% in the surgical group. The Harris hip score was significantly improved following surgery when compared with non-surgical treatment (P<0.05). The results indicated that core decompression and porous tantalum rod implantation are beneficial short- and mid-term treatment methods for AVN of the femoral head.

Repair of non-traumatic femoral head necrosis by marrow core decompression with bone grafting and porous tantalum rod implantation.

Objective:To compare the clinical effects of marrow core decompression with bone grafting and marrow core decompression with porous tantalum rod implantation in treating avascular necrosis of non-traumatic femoral head.Methods:This prospective study selected 60 patients (74 hips) with avascular necrosis of femoral head admitted to Daping Hospital from January 2018 to March 2019. According to treatment methods, the 60 patients were randomly divided into two groups, i.e. 30 patients in one group were treated by marrow core decompression with bone grafting, and the other 30 patients in the other group were treated with marrow core decompression and porous tantalum rod implantation.Results:All implantation treatments were successful. No significant difference was found in surgical duration, hemorrhage volume and duration of hospitalization stay between the two groups during follow-up. All Harris scores were significantly improved (P<0.05) following treatment compared to those before treatment. The Harris score of patients treated with porous tantalum rod implantation was higher than that of patients treated with bone grafting (P<0.05) after 12 months following treatment and such a difference was significant.Conclusion:The combination of marrow core decompression and porous tantalum rod implantation can better improve the functions of hip joints with early femoral head necrosis than marrow core decompression with bone grafting, and can also prevent articular cartilage from collapsing gradually.

Clinical effects of the implantation of porous tantalum rod under three-dimensional C-arm positioning in treating ARCO I-II non-traumatic necrosis of the femoral head

Objective To evaluate the clinical effects of the implantation of porous tantalum rod under three-dimensional (3D) C-arm positioning in the treatment of ARCO I and II non-traumatic femoral head necrosis. Methods Fifty patients (58 hips, 39 males and 11 females, mean age 33.52 years) with non-traumatic femoral head in ARCO I-II were included from January 2009 to December 2011. All patients received implantation of porous tantalum rod. The 3D C-arm X-ray positioning was used in 24 patients (29 hips), while traditional C-arm X-ray positioning was performed in the other patients. The visual analogue scale (VAS), Harris score and superior rate were evaluated at 0.5, 1, 2, and 4 years after the surgery. Total hip arthroplasty was regarded as the end event for survival rate. Results In the 3D C-arm X-ray positioning group, the VAS score decreased from 7.17±1.00 points preoperatively to 2.38±0.86 points at half year, to 2.10±1.40 points at 1 year, to 2.38±1.66 points at 2 years, and to 2.21±1.47 points at 4 years postoperatively (F=98.78, P=0.00). Meanwhile, the Harris score increased significantly from 73.97±3.49 points preoperatively to 89.90±1.93, 89.93±3.26, 89.21±5.83, 88.57±5.70 points at the follow up, respectively (F=84.35, P=0.00). According to the analysis of the pre-operative and post-operative image data, there was no significant difference in progress in the ARCO staging at 23 hips duration the follow-up. Four hips were developed to ARCO III and two hips to ARCO II. Thus, the success rate of operation was 79% (23/29). There were two hips underwent total hip arthroplasty, so the survival rate of femoral head was 93% (27/29). The trend of VAS score and Harris score in the C-arm X-ray positioning group was in accordance with the 3D C-arm X-ray positioning group but without statistically significant difference (P>0.05). The operation duration 31.38±3.96 min, blood loss 36.72±5.59 ml, the ratio of distance of metal rod to bone cortex in femoral neck 0.48±0.10, and the distance of mental rod to center of necrosis 0.18±0.07 cm in 3D C-arm X-ray positioning group was superior to C-arm X-ray positioning group (respectively 41.97±4.64 min, 41.49±4.46 ml, 0.46±0.06, 0.23±0.10 cm, P<0.05). Conclusion The implantation of tantalum rod in treating ARCO I-II non-traumatic femoral head necrosis can increase the function of hip joint, relieve the symptoms of necrosis of femoral head, alleviate the progress of femoral head necrosis in X-ray, and obtain a higher survival rate. The 3D C-arm positioning in surgical operation could improve the accuracy and safety of surgery. Key words: Femur head necrosis; Tantalum; Imaging, three-dimensional; X-rays; Radiography

Three-dimensional finite element analysis of silk protein rod implantation after core decompression for osteonecrosis of the femoral head

BackgroundSeveral methods are available for the treatment of early-stage osteonecrosis of the femoral head. Core decompression with implantation is a widely-used treatment. However, no single implant is recognized as the most effective way to prevent disease progression. Silk has high strength and resiliency. This study explored the possibility of a strong and resilient silk protein biomaterial as a new alternative implant.MethodsWe investigated the biomechanical properties of the silk protein material by regular compression, torsion, and three-point bending tests. We established three-dimensional finite element models of different degrees of femoral head osteonecrosis following simple core decompression, fibula implantation, porous tantalum rod implantation, and silk protein rod implantation. Finally, we compared the differences in displacement and surface stress under load at the femoral head weight-bearing areas between these models.ResultsThe elastic modulus and shear modulus of the silk protein material was 0.49GPa and 0.66GPa, respectively. Three-dimensional finite element analyses demonstrated less displacement and surface stress at the femoral head weight-bearing areas following silk protein rod implantation compared to simple core decompression (p < 0.05), regardless of the extent of osteonecrosis. No differences were noted in the surface deformation or surface stress of the femoral head weight-bearing areas following silk protein rod, fibula or tantalum rod implantation (p > 0.05).ConclusionsWhen compared with simple core decompression, silk protein rod implantation demonstrated less displacement and surface stress at the femoral head weight-bearing area, but more than fibula or tantalum rod implantation. Similar effects on the surface stress of the femoral head between the silk rod, fibula and tantalum rod implantations, combined with additional modifiable properties support the use of silk protein as a suitable biomaterial in osteonecrosis surgery.

Peripheral Blood Stem Cell Therapy Does Not Improve Outcomes of Femoral Head Osteonecrosis With Cap‐Shaped Separated Cartilage Defect

A combination treatment with porous tantalum rod implantation and intra-arterial infusion of peripheral blood stem cells (PBSCs) provides a promise for treating early and intermediate stages of osteonecrosis of the femoral head (ONFH). However, its clinical indications and application restrictions remain unclear. This study aims to determine the clinical, histological, and radiological outcomes of a combination treatment using mechanical support and a targeted intra-arterial infusion of PBSCs for painful ONFH with a cap-shaped separation (CSS) cartilage defect. Compared with the standard pain management (control group), this combination treatment did not improve the Harris Hip Score (HHS) at 36 months. Micro-CT and histologic analyses showed severe focal destruction in all CSS-ONFH femoral heads in both the combination and control groups. Femoral heads showed a higher percentage of bone lesions in the combination treatment group than in the control group. There was no significant difference in osteoclast number in the subchondral bone areas between the two groups. A high level of expression of inflammatory cytokines, including tumor necrosis factor-α and interleukin-1β, was detected in blood vessels around the subchondral bone in both groups. The RANKL/OPG (receptor activator of the nuclear factor-kB ligand/osteoprotegerin) ratio was also similar between the control and combination treatment groups. Our results indicate that this combination treatment is not an effective method for the treatment of patients with painful CSS-ONFH. Moreover, this combination treatment did not inhibit inflammatory osteoclastogenesis in patients with more advanced disease. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:269-276, 2020.