Icariin-loaded 3D-printed porous Ti6Al4V reconstruction rods for the treatment of necrotic femoral heads

Avascular necrosis of the femoral head is a prevalent hip joint disease. Due to the damage and destruction of the blood supply of the femoral head, the ischemic necrosis of bone cells and bone marrow leads to the structural changes and the collapse of the femoral head. In this study, an icariin-loaded 3D-printed porous Ti6Al4V reconstruction rod (referred to as reconstruction rod) was prepared by 3D printing technology. The mechanical validity of the reconstruction rod was verified by finite element analysis. Through infilling of mercapto hyaluronic acid hydrogel containing icariin into the porous structure, the loading of icariin was achieved. The biological efficacy of the reconstruction rod was confirmed through in vitro cell experiments, which demonstrated its ability to enhance MC3T3-E1 cell proliferation and facilitate cellular adhesion and spreading. The therapeutic efficacy of the reconstruction rod was validated in vivo through a femoral head necrosis model using animal experiments. The results demonstrated that the reconstruction rod facilitated osteogenesis and neovascularization, leading to effective osseointegration between bone and implant. This study provides innovative strategy for the treatment of early avascular necrosis of the femoral head. STATEMENT OF SIGNIFICANCE: The bioactivity of medical titanium alloy implants plays an important role in bone tissue engineering. This study proposed a medicine and device integrated designed porous Ti6Al4V reconstruction rod for avascular necrosis of the femoral head, whose macroscopic structure was customized by selective laser melting. The bionic porous structure of the reconstruction rod promoted the growth of bone tissue and formed an effective interface integration. Meanwhile, the loaded icariin promoted new bone and vascular regeneration, and increased the bone mass and bone density. Therefore, the implantation of reconstruction rod interfered with the further development of necrosis and provided a positive therapeutic effect. This study provides innovative strategies for the treatment of early avascular necrosis of femoral head.

Reconstructing avascular necrotic femoral head through a bioactive β-TCP system: From design to application

A variety of techniques have been used for treating avascular necrosis of the femoral head (ANFH), but have frequently failed. In this study, we proposed a β-TCP system for the treatment of ANFH by boosting revascularization and bone regeneration. The angio-conductive properties and concurrent osteogenesis of the highly interconnected porous β-TCP scaffold were revealed and quantified through an in vivo model that simulated the ischemic environment of ANFH. Mechanical test and finite element analysis showed that the mechanical loss caused by tissue necrosis and surgery was immediately partially compensated after implantation, and the strength of the operated femoral head was adaptively increased and eventually returned to normal bone, along with continuous material degradation and bone regeneration. For translational application, we further conducted a multi-center open-label clinical trial to assess the efficacy of the β-TCP system in treating ANFH. Two hundred fourteen patients with 246 hips were enrolled for evaluation, and 82.1% of the operated hips survived at a 42.79-month median follow-up. The imaging results, hip function, and pain scores were dramatically improved compared to preoperative levels. ARCO stage Ⅱ disease outperformed stage Ⅲ in terms of clinical effectiveness. Thus, bio-adaptive reconstruction using the β-TCP system is a promising hip-preserving strategy for the treatment of ANFH.

Combining autologous bone marrow buffy coat and angioconductive bioceramic rod grafting with advanced core decompression improves short-term outcomes in early avascular necrosis of the femoral head: a prospective, randomized, comparative study

Background

Treatment of avascular necrosis of the femoral head (ANFH) in young patients remains a clinical challenge. A current controversy is whether hip-preserving surgery results in better outcomes. The adverse effects of hip-preserving surgery are associated with the fill material for the necrotic areas. This study aims to evaluate the early effects of autologous bone marrow buffy coat (BBC) and angioconductive bioceramic rod (ABR) grafting with advanced core decompression (ACD) on early ANFH.

Methods

Forty-four (57 hips) patients with early ANFH from 2015 to 2020 were recruited for this study. They were randomized into two groups: group A received ACD, BBC, and ABR grafting; group B received treatment of ACD with β-tricalcium phosphate (β-TCP) granules and ABR grafting. The outcomes were assessed using the Harris Hip Scores (HHS) and survival rate analysis. The follow-up endpoint was defined as conversion to total hip arthroplasty (THA).

Results

Forty patients (51 hips) were ultimately included in this study for analysis. Compared with group B, patients in group A had higher postoperative function score (P = 0.032) and postoperative Harris Hip Scores (HHS) (P = 0.041). Kaplan-Meier analysis showed a trend that the survivorship of the femoral head was higher in group A than in group B.

Conclusion

The short-term follow-up results showed that the autologous bone marrow buffy coat and angioconductive bioceramic rod grafting with advanced core decompression is effective in the treatment of early ANFH.

Trial registration

Chictr.org.cn, ChiCTR2000039595. Retrospectively registered on 11 February 2015.

A novel mutation of COL2A1 in a large Chinese family with avascular necrosis of the femoral head

Avascular necrosis of the femoral head (ANFH) is a debilitating bone disease, characterized by collapse of the femoral head and subsequent loss of hip joint function. Heterozygous mutations in COL2A1 have been identified to cause familial ANFH. Here we report on a large Chinese family with ANFH and a novel heterozygous mutation (c.3517 G > A, p.Gly1173Ser) in exon 50 of COL2A1 in the Gly-X–Y domain. Previously, only five different COL2A1 mutations have been described in patients with familial ANFH. Therefore, our findings provide significant clues to the phenotype–genotype relationships in familial ANFH and may be helpful in clinical diagnosis. Furthermore, these results should assist further studies of the mechanisms underlying collagen diseases.

[Partial hip resurfacing-a critical analysis]

BACKGROUND

Localized cartilage lesions or osteochondral defect areas of the hip joint often affect young patients with an active professional and personal live. There are multiple causes of these defect zones, but they determine the therapeutic options to some extent.

THERAPEUTIC OPTIONS

In addition to the domain of joint-preserving, implant-free hip surgery, so-called mini-prostheses or partial implants represent another treatment strategy prior to the application of a total hip arthroplasty (THA). In the following, partial joint resurfacing implants (e. g., HemiCAP®, Arthrosurface, Franklin, MA, USA) are presented and results from the literature are cited. The described procedure is not widely offered, especially in Germany, because most indications are congruent with those for implantation of a THA, which is an established technique. Consequently, the results from the literature are based on case series with inferior validity compared to the studies and registry data of the THA and accordingly have to be scrutinized in a more critical way. Total surface replacement (hip resurfacing, e.g., Birmingham hip replacement, BHR, Smith and Nephew, Memphis, TN, USA) distinguish from partial surface replacement. On the one hand the BHR shows parallels with regard to the femoral surface reconstruction, but on the other hand due to the obligatory replacement of the acetabular side of the joint it meets conditions of THA, which can therefore play at best an intermediate role between a stem-anchored THA and a partial replacement.

Clinical value of digital tomographic fusion imaging in the diagnosis of avascular necrosis of the femoral head in adults

Background

To explore the clinical significance of digital tomographic fusion imaging in the diagnosis of avascular disease of the femoral head in adults.

Methods

Eighty-two adult patients with avascular necrosis of the femoral head confirmed by MRI in the department of orthopedics of our hospital were studied retrospectively. The related signs of adult avascular necrosis of the femoral head were diagnosed by digital tomographic fusion imaging, and the detection rates of digital X-ray (DR) and digital tomosynthesis (DTS) were compared to clarify the clinical value of digital tomographic fusion imaging in the diagnosis of adult avascular necrosis of the femoral head.

Results

DTS detected DR and 78 cases identified 55 cases. Taking the results of CT/MRI as the gold standard, the sensitivity, specificity, positive predictive value, and negative predictive value of DR and DTS in the diagnosis of ANFH were calculated. There was a significant difference in the detection rate between the two methods (P < 0.05).

Conclusion

The digital tomographic fusion imaging technique has the advantages of high detection rate and excellent image quality, is economical, and is worth popularizing. For those with negative X-rays, DTS diagnosis and CT or/and MRI can avoid unnecessary CT and MRI examinations, which is helpful to reduce the waste of medical resources.

Efficacy of closed reduction for developmental dysplasia of the hip: midterm outcomes and risk factors associated with treatment failure and avascular necrosis

BACKGROUND

The purpose of this study was to evaluate the efficacy of closed reduction (CR) in the treatment of developmental dysplasia of the hip (DDH) and to investigate risk factors associated with CR failure and avascular necrosis (AVN) occurrence in follow-ups.

METHODS

The study retrospectively included 110 patients and 138 hips with DDH diagnosis that underwent closed reduction between February 2012 and November 2015 in our single tertiary medical institution. The failure rate of CR and the underlying risk factors were evaluated. Meanwhile, the incidence of AVN and the related risk factors among the successful CR cases were assessed.

RESULTS

The overall failure rate of DDH treated by CR in the present study was 31.16% (43/138). Risk factors for the CR failure were older age at the time of CR (≥ 18.35 month), large medical interval before CR (≥ 35.35 mm), and severer dislocation of the affected hip (IDHI grades III and IV). The incidence of AVN was 8.33% (6/72) in patients with successful CR at the last follow-up. No significant risk factors had been established in the present study that associated with the AVN occurrence.

CONCLUSIONS

For the treatment of DDH with CR, patients with younger age might achieve better outcomes; early diagnosis and early treatment might be the key point in the DDH treatment.

Avascular necrosis of the femoral head after traumatic posterior hip dislocation with and without acetabular fracture

PURPOSE

Traumatic hip dislocation can be isolated or associated with acetabular fracture. Both injuries require emergency reduction of the dislocated hip. Avascular necrosis of the femoral head (AVN) is a potential complication that accompanies these severe injuries. Our objective is to identify the risk factors that cause AVN.

METHODS

We retrospectively analyzed 44 patients with traumatic hip dislocations (Group A) and patients with posterior fracture-dislocation of the acetabulum (Group B). The average follow-up was 5.38 years in Group A, 5.59 years in Group B. We used the Thompson-Epstein classification for hip dislocation and the Harris Hip Score (HHS) for evaluating final outcomes.

RESULTS

In Group A, we analyzed 21 patients with isolated posterior hip dislocation. We had one (4.76%) case of AVN. In Group B, we analyzed 23 patients with posterior acetabular fracture-dislocation. We had eight (34.78%) patients with AVN (p = 0.016, p < 0.05). With hip reduced 6-12 h after injury, we had AVN in one (4.34%) patient, with reduction 12-24 h, AVN was present in two (8.69%), while in hip reduction done after 24 h of injury, AVN was present in five (21.73%) patients (p = 0.030, p < 0.05).

CONCLUSION

An essential prerequisite for the prevention of AVN of the femoral head after hip dislocation is emergency hip reduction. In acetabular fracture-dislocation, emergency hip reduction, anatomical reduction of the acetabular fracture and early stable osteosynthesis are also important. Main factor affecting the development of AVN is late reduction of the hip.

10-year follow-up results of the prospective, double-blinded, randomized, controlled study on autologous bone marrow buffy coat grafting combined with core decompression in patients with avascular necrosis of the femoral head

Background

Avascular necrosis of the femoral head (ANFH) is a severely disabling disease of the hip. Several clinical trials have shown promising outcomes on the use of mesenchymal stem cells for the treatment of ANFH, but long-term clinical assessments are lacking. Previously, we reported the 2-year follow-up results of a prospective, double-blinded, randomized, controlled study on autologous bone marrow buffy coat grafting combined with core decompression in patients with ANFH. Here, we report the 10-year follow-up results of this study.

Methods

We recruited 43 (53 hips) patients from 2009 to 2010. The hips were randomly allocated to code decompression (CD) with or without bone marrow buffy coat (BBC) grafting. Participants underwent follow-up at 24, 60, and 120 months postoperatively. The visual analogue scale (VAS), Lequesne algofunctional index, and Western Ontario and McMaster Universities Arthritis Index (WOMAC) osteoarthritis scores were recorded. Survival rate analysis and prognostic factor analysis were performed. The endpoint was defined as progression to Ficat stage IV or conversion to hip arthroplasty.

Results

A total of 31 patients (41 hips) were included in the final analysis. The CD + BBC group had better subjective assessment scores than the CD group. The average survival times were 102.3 months and 78.1 months in the CD + BBC group and CD group, respectively (log-rank test, P = 0.029). In the univariate Cox proportional hazards regression model, age [hazard ratio (HR) = 1.079, P = 0.047] and preoperative Ficat stage (HR = 3.283, P = 0.028) indicated a high risk for progression, while the use of BBC (HR = 0.332, P = 0.042) indicated a low risk. Preoperative Ficat stage III was isolated as an independent risk factor for clinical failure in the multivariate model (HR = 3.743, P = 0.018).

Conclusion

The 10-year follow-up results of this prospective, double-blinded, randomized, controlled study showed that the use of autologous BBC in combination with core decompression was more effective than the use of core decompression alone.

Trial registration

ClinicalTrials.gov, NCT01613612. Registered on 13 December 2011—retrospectively registered

Treatments of avascular osteonecrosis of the hip: Current treatments

Conservative treatments for aseptic osteonecrosis of the femoral head have their ancestor in the core decompression of the femoral neck, recommended by Ficat. Due to inconsistent results, this treatment has been optimized by either vascularized fibular grafting, or by injecting autologous stem cells into the necrotic zone. The French promoters have published long-term results, showing efficacy in the early stages of the disease, where the femoral head has not yet lost its sphericity. Over the last 10years, comparative studies, sometimes randomized, opposing them to simple core decompression, have been published by non-promoters, confirming the possibility of stabilization or even regression of necrosis area. But these techniques are not easy to implement. Cell therapy requires treatment of marrow samples by centrifugation to obtain a pellet with a high concentration of haematopoietic cells. The now proven long-term efficacy as well as the safety of this technique make it the method of choice for treating young patients detected at the sub-radiological stage by MRI. Unfortunately, many are seen late with detached cephalic cartilage or collapsed femoral head and have no other option than total hip arthroplasty. This technique is very reliable. With alumina ceramics, results of more than 20years show the absence of wear and osteolysis, although other complications such as instability or periprosthetic fractures may occur in these young and active patients.

Surgical hip dislocation with femoral osteotomy and bone grafting prevents head collapse in hips with advanced necrosis

QUESTIONS

Does surgical hip dislocation with drilling or bone grafting, cartilage treatment and femoral osteotomy in avascular necrosis of the femoral head (AVN) result in: (1) progression of osteonecrosis or osteoarthritis; (2) pain relief and improved function; and (3) subsequent surgery and complications?

METHODS

We retrospectively reviewed 12 patients (13 hips, mean age 29 ± 9 years) undergoing surgical hip dislocation for AVN. Preoperative ARCO stages were: 1 hip ARCO II, 8 hips ARCO III early, 4 hips ARCO III late. Drilling was performed in 4 hips, 9 hips underwent curettage, drilling and autologous bone grafting. Cartilage was sutured in 5 hips, autologous matrix-induced chondrogenesis was performed in 3 hips, an osteochondral autograft was used in 1 hip. Femoral osteotomy was performed in 10 hips. Mean follow-up was 3 ± 2 years. Progression of AVN and osteoarthritis was assessed preoperatively and at latest follow-up using Tönnis and ARCO staging. Pain and function were assessed with the Merle d'Aubigné-Postel score. Complications were graded according to Sink et al.

RESULTS

1 hip had AVN progression and converted to THA. 9 hips showed no AVN- or advanced osteoarthritis progression and 3 hips improved at least 1 ARCO stage. The Merle d'Aubigné-Postel score increased from preoperatively 14.1 ± 3.2 to 16.6 ± 1.2 (p = 0.012). Subsequent surgery were performed in 3 hips, complications occurred in 3 hips.

CONCLUSION

Although the first results are promising a longer follow-up with more patients is needed to draw a definite conclusion regarding the joint preserving potential in AVN.

A Comparative Study of Clinical and Radiological Outcomes of Open Reduction Using the Anterior and Medial Approaches for the Management of Developmental Dysplasia of the Hip

BACKGROUND

The literature is scanty on reports directly comparing the outcomes of anterior open reduction (AOR) and medial open reduction (MOR) in the management of developmental dysplasia of the hip (DDH).

PURPOSE OF THE STUDY

To compare clinical and radiographic outcomes of surgical treatment using either AOR or MOR in children with DDH aged < 24 months and to evaluate the procedure-inherent risks of avascular necrosis of the femoral head (AVN) and need for further corrective surgery (FCS).

METHODS

61 children who underwent surgical treatment for DDH were categorized into two groups: AOR (31 hips of 28 patients) and MOR (39 hips of 33 patients). The mean age was 17 ± 5.85 (range 7-24) months in group AOR and 13 ± 5.31 (range 6-24) months in group MOR. The mean follow-up was 118 ± 41.2 (range 24-192) months and 132 ± 36.7 (range 24-209) months in group AOR and MOR. At the final follow-up, mid- to long-term clinical and radiographic outcomes were assessed. FCS was recorded.

RESULTS

Regarding McKay's clinical criteria, both groups exhibited similar results (p = 0.761). No significant differences were observed between the groups in both the center-edge-angle (p = 0.112) and the Severin score (p = 0.275). The AVN rate was 32% in the AOR group and 20% in the MOR group (p = 0.264). The FCS rate was 22% in the AOR group and 12% in the MOR group (p = 0.464).

CONCLUSIONS

This study showed similar clinical and radiological outcomes with AOR and MOR with no significant relation to AVN and FCS.

LEVEL OF EVIDENCE

Level III.

[Hip preservation experience of avascular necrosis of femoral head according to China-Japan Friendship Hospital classification]

Objective

To sum up staging treatment experiences of hip preservation for avascular necrosis of the femoral head (ANFH) according to China-Japan Friendship Hospital Classification (CJFH Classification).

Methods

The literature about hip preservation of ANFH was extensively reviewed, and a staging treatment method for ANFH was set up base on CJFH Classification and the 28 years of clinical experience in this research group.

Results

According to CJFH Classification, the ANFH can be rated as types M, C, and L. And the type L is rated as L1, L2, and L3 subtypes. The staging treatment method for ANFH based on CJFH Classification is set up. Conservative treatment was selected for CJFH-M patients because the necrotic area is small and in the medial non-weight-bearing area. Minimally invasive sequestrum clearance, impacting bone graft, and supporting allogenic fibular graft is selected for CJFH-C patients because the necrotic area is also small and in the lateral non-weight-bearing area. If patients are in CJFH-L1, normal bone area is less than 1/3 on hip abduction radiograph, the sequestrum clearance and impacting bone graft via surgical hip dislocation approach can be selected. If patients are in CJFH-L1, normal bone area is more than 1/3 on hip abduction radiograph, the transtrochanteric curved varus osteotomy can be selected. The rotational osteotomy on the base of femoral neck via surgical hip dislocation approach is for CJFH-L2 patients. Total hip arthroplasty via direct anterior approach is for CJFH-L3 patients.

Conclusion

The staging treatment method for ANFH according to CJFH Classification has good short-term effectiveness. But the long-term effectiveness needs further follow-up.

The effect of robot-navigation-assisted core decompression on early stage osteonecrosis of the femoral head

BACKGROUND

The aim of the current paper is to evaluate the effects of robot-navigation-assisted core decompression compared with conventional core decompression surgery for early-stage osteonecrosis of the femoral head.

METHODS

Twenty patients with a total of 36 hips who were diagnosed with Association Research Circulation Osseous stage 2 avascular necrosis of the femoral head and who received core decompression with or without robotic assistance were reviewed. The Harris hip score and visual analog scale score were used to assess clinical function. Intraoperative radiation exposure and operation time were used to evaluate the effectiveness of the robot-assisted system.

RESULTS

At a mean follow-up of 26.4 months (24-36 months), the Harris hip score, visual analog scale score, and survival rate of the patients were similar between the conventional and robot-assisted groups. The guidewire insertion time, number of guidewire attempts, and radiation exposure during guidewire insertion were all significantly lower in the robot-assisted group than in the conventional group.

CONCLUSIONS

Robot-assisted core decompression of the femoral head is as safe and effective as a conventional core decompression surgery. It can reduce operation time and decrease intraoperative radiation exposure.

Outcome of the modified Dunn procedure in severe chronic or acute on chronic slipped capital femoral epiphysis

Background

In recent years, the modified Dunn osteotomy has gained popularity to treat slipped capital femoral epiphysis (SCFE) with various complication rates. Most studies included patients with different severities. This study aimed to determine (1) the radiological and clinical outcome, (2) the health-related quality of life, and (3) the incidence of avascular necrosis of the femoral head (AVN) in patients with severe chronic or acute on chronic SCFE treated by the modified Dunn procedure.

Methods

Out of 150 patients with SCFE treated at our institution between 2001 and 2014, 15 patients (mean age 12.9 years (range 11.8–15)) were treated by the modified Dunn procedure. Eight SCFE were chronic and 7 acute on chronic. All slips were severe with a mean Southwick slip angle (SSA) of 67° (range 60–80). Radiographic and clinical outcomes were measured. Mean time of follow-up was 3.8 years (range 1–10).

Results

Anatomical reduction was achieved in all cases. Good radiological results according to the Stulberg Classification (grade 1 + 2) and the Sphericity Deviation Score (< 30) were found in 9 out of 13 patients at the last follow-up. Clinical and functional outcome analysis revealed good results in 8 out of 10 patients (Harris Hip Score > 80). The quality of life measured by the Nottingham Health Profile (NHP) was described good in 10 out of 10 patients. Four out of 15 patients developed an AVN.

Conclusions

The modified Dunn procedure has a great potential to restore proximal femur geometry in severe chronic or acute on chronic SCFE. It should be considered only if there is no other possibility to restore proximal femur geometry, as is the case in severe slips, due to the risk of AVN.

[Impacting bone graft via surgical hip dislocation approach versus core decompression and bone graft for avascular necrosis of femoral head at ARCO stage ]

Objective

To compare the effectiveness of sequestrum clearance and impacting bone graft via surgical hip dislocation approach and core decompression and bone graft for avascular necrosis of the femoral head (ANFH) at Association Research Circulation Osseous (ARCO) stage Ⅲ.

Methods

A clinical data of 60 patients (69 hips) of non-traumatic ANFH at ARCO stage Ⅲ, which met the inclusion criteria between October 2013 and April 2016, was retrospectively analyzed. Among them, 24 patients (28 hips) were treated with sequestrum clearance and impacting bone graft via surgical hip dislocation approach (group A); and 36 patients (41 hips) were treated with core decompression, sequestrum clearance, impacting bone graft, and nonvascular fibular allograft supporting (group B). There was no significant difference in gender, age, disease duration, affected side, type and stage of the ANFH, and preoperative Harris hip score and visual analogue scale (VAS) score between the two groups ( P>0.05). After operation, the function of the hip was evaluated by Harris hip score, imaging examination was performed to observe the femoral head shape and evaluate whether the hip preserving success.

Results

The incisions of two groups healed by first intention. All patients were followed up. The follow-up time was 12-48 month (mean, 25.8 months) in group A and 12-54 months (mean, 26.4 months) in group B. At last follow-up, 5 hips in group A were classified as clinical failure, femoral head survival rate was 82.1%, the median survival time was 43 months. While 19 hips in group B were classified as clinical failure, femoral head survival rate was 53.7%, the median survival time was 42 months. There was significant difference in survival curve distribution between the two groups ( χ ²= 4.123, P=0.042), and the surgical procedures of group A was superior to group B. In the two groups, the Harris hip scores at last follow-up were significantly higher than preoperative ones ( P<0.05), and VAS scores were significantly lower than preoperative ones ( P<0.05). There was no significant difference in Harris hip score and VAS score at last follow-up between the two groups ( P>0.05). All grafted bones got fusion according to the X-ray films, and there was no significant difference in the fusion time between the two groups ( t=0.752, P=0.456). In group A, greater trochanter bone cutting were healed well; and the heterotopic ossification around the hip joint occurred in 1 case.

Conclusion

The surgery of impacting bone graft via surgical hip dislocation approach and core decompression and bone graft can be applied to treat ANFH at ARCO stage ⅢA which was mild collapse and satisfactory effectiveness can be obtained. While for the patients of ANFH at ARCO stage Ⅲ B with severe collapse, the hip survival rate of the former is better than that of the latter.

Effects of transplantation of FGF-2-transfected MSCs and XACB on TNF-α expression with avascular necrosis of the femoral head in rabbits

Objective: The present study aimed to investigate the effect of the transplantation of basic fibroblast growth factor (FGF-2) gene-transfected mesenchymal stem cells (MSCs) and xenogeneic antigen-cancellous bone (XACB) on tumor necrosis factor-α (TNF-α) expression with avascular necrosis of the femoral head (ANFH) in rabbits. Methods: The models of steroid-induced osteonecrosis in rabbits were randomly divided into five groups: A (model), B (XACB), C (XACB + MSCs), D (XACB + MSCs + LV), and E (XACB + MSCs + LV-FGF-2) groups. The therapeutic effect was evaluated by Hematoxylin and Eosin (H&E) staining. Immunohistochemical and RT-PCR assays were used to detect the protein and mRNA expression of TNF-α in the femoral head, respectively. Results: At 12 weeks after the operation, the defect in rabbits in group E was completely repaired, while defects in rabbits in the other groups were not completely repaired, and the area of new bone formation was higher, when compared with the other groups (P<0.05). Furthermore, the protein and mRNA expression TNF-α was lower at 3, 6, and 12 weeks after surgery, when compared with the other groups, and the difference was statistically significant (P<0.05). Conclusion: FGF-2/MSCs/XACB could promote the repair of ANFH, and may be correlated to the inhibition of TNF-α expression.

Radiological and clinical outcomes of medial approach open reduction by using two intervals in developmental dysplasia of the hip

OBJECTIVE

To evaluate the midterm clinical and radiological outcomes of the medial approach using two intervals for developmental hip dysplasia (DDH).

METHODS

The study involved 62 hips of 47 patients (41 girls, 6 boys) treated with medial approach for DDH from 1999 to 2010. The age of the patients at surgery was 18.7 ± 2.25 months. Follow up of the patients was 11.3 ± 3.07 years. The age of the patients at the last follow up was 12.6 ± 1.74 years. According to the Tönnis classification, 13 hips were grade II, 27 hips were grade III and 22 hips were grade IV. Patients were evaluated according to Omeroglu radiological criteria and modified McKay functional criteria. The presence of avascular necrosis (AVN) of the hip was questioned using the KalamchiMacEwen classification.

RESULTS

Radiologically, forty eight (77%) hips were evaluated as "excellent", 8 (13%) hips as "good" and 5 (8%) hips as "fair plus" and 1 (%2) hip as "fair minus". Two (3%) patients had type 1 temporary AVN and one (1%) patient had type 4 AVN with coxa magna and overgrowth of the greater trochanter. According to McKay functional criteria, 56 (90%) hips had "excellent" and 6 (10%) had "good" results. Two (3.2%) hips of one patient had to be reoperated with Salter osteotomy and femoral shortening + derotation osteotomy.

CONCLUSION

Medial approach using two separate intervals for tenotomy and capsulotomy does not jeopardize the medial circumflex or the femoral vessels and yields satisfactory midterm results for children 18 months old with dysplasia of the hip.

LEVEL OF EVIDENCE

Level IV, therapeutic study.

Femoral osteochondroplasty can be performed effectively without the risk of avascular necrosis or femoral neck fractures in an experimental ovine FAI model

OBJECTIVE

The experimental induction of cam-type femoroacetabular impingement (FAI) in sheep is established. To tap the full potential of this ovine model, one should be able to perform a femoral osteochondroplasty safely. This study was based on previous cadaver experiments on the blood supply to the ovine femoral head and on the biomechanical strength of the proximal femur following offset creation. We hypothesized that offset creation in this ovine FAI model does not lead to (1) avascular necrosis (AVN) of the ovine femoral head or (2) iatrogenic femoral neck fractures and (3) can be performed effectively.

DESIGN

In this experimental, controlled, prospective study nine sheep underwent unilateral FAI induction through an intertrochanteric, varus osteotomy. Seventy days following FAI induction, femoral osteochondroplasty was performed. Sheep were sacrificed after another 140 days. Radiographs, computed tomography (CT) scans and MRI were acquired. Histologic samples were stained with hematoxylin-eosin. (1) The multimodal Association Research Circulation Osseous (ARCO) classification was used for assessment of AVN. (2) Femoral neck fractures were assessed with the multimodal imaging approach. (3) Pre- and postoperative (=after sacrifice) alpha angles and femoral neck diameters were compared.

RESULTS

(1) No signs for AVN according to the ARCO classification or (2) for femoral neck fractures were detected. (3) Mean alpha angles and femoral neck diameters decreased significantly (p < 0.001) superiorly by at least 30° respectively 4 mm after the offset creation.

CONCLUSIONS

Femoral osteochondroplasty can be performed effectively and without the risk of AVN or femoral neck fractures in this ovine FAI model.

Dyslipidaemia for patients with low-energy femoral neck fractures after the treatment of cancellous screws: a retrospective study with a 3-year minimum follow-up

Background

Avascular necrosis of the femoral head (AVNFH) occurs infrequently following femoral neck fracture. The association between AVNFH and dyslipidaemia remains controversial. Although major risk factors for AVNFH have been proposed, most of them remain under discussion. Our purpose herein was to evaluate the association between dyslipidaemia and AVNFH following low-energy femoral neck fractures treated with cancellous screws in elderly patients in our tertiary care centre.

Methods

Four hundred and seventy-two consecutive patients (472 hips) with low-energy femoral neck fractures were identified and treated with cancellous screws from July 2007 to April 2013. Patients underwent evaluations preoperatively and each subsequent postoperative visit (months 1, 6, 12, 18, 24, 30, and 36). Clinical and radiographic evaluations were documented at each visit. The risk factors of AVNFH were assessed by multivariate binary logistic analysis.

Results

Follow-up was available for 277 patients, which included 135 patients diagnosed with AVNFH (AVNFH group) and 142 patients without AVNFH (control group). The median follow-up for patients alive at the time of analysis was 40 months (range, 37 to 46 months). The mean total cholesterol (TC), triglyceride (TG), low density lipoprotein cholesterol (LDL-C), and apolipoprotein B (Apo-B) values were considerably higher in the AVNFH group compared with those in the control group. The mean high density lipoprotein cholesterol (HDL-C) and apolipoprotein A1(Apo-A1) values were significantly lower in the AVNFH group compared with those in the control group. A multivariate logistic backward regression model showed that HDL-C and LDL-C were the only variables associated with the development of postoperative AVNFH in patients with a femoral neck fracture (Odds ratio[OR] 33.09, 95% Confidence Interval[CI]: 2.65–19.42, p < 0.001 and OR 45.94, 95% CI: 0.47–27.75, p < 0.001, respectively).

Conclusion

Our results suggest that both low HDL-C and high LDL-C have a tendency to result in the occurrence of AVNFH in elderly patients with low-energy femoral neck fractures treated with cancellous screws.

Cortisol inhibits mTOR signaling in avascular necrosis of the femoral head

BACKGROUND

ANFH is a major health problem, to which long lasting and definitive treatments are lacking. The aim of this study is to study RNA alterations attributed to cortisol-induced ANFH.

METHODS

Rat models were stratified into three groups: in vitro group (n = 20) for molecular biological assays, control group (n = 3), and ANFH group induced using lipopolysaccharide and dexamethasone (n = 3). Bone marrow-derived endothelial progenitor cells (BM-EPCs) were extracted from the rats. An RNA expression array was performed on BM-EPCs, and enriched genes were subject to pathway analysis. In vitro studies following findings of array results were also performed using the isolated BM-EPCs.

RESULTS

Significant alterations in mammalian target of rapamycin (mTOR) and HIF signaling pathways were identified in BM-EPCs of ANFH. By applying cortisol and dexamethasone to BM-EPCs, significant changes in mTOR and HIF elements were identified. The alteration of HIF pathways appeared to be downstream of mTOR signaling. Glucocorticoid receptor (GR) expression was related to glucocorticoid-dependent mRNA expression of mTOR/HIF genes. mTOR-dependent angiogenesis but not anabolism was the target of GR in ANFH. Inhibition of mTOR signaling also induced apoptosis of BM-EPCs via CHOP-dependent DR5 induction in response to GR stimulation.

CONCLUSION

Decreased mTOR signaling in response to GR stimulation leading to downregulated HIF pathway as well as increased apoptosis could be the pathophysiology.

The impact of high total cholesterol and high low-density lipoprotein on avascular necrosis of the femoral head in low-energy femoral neck fractures

Background

Avascular necrosis of the femoral head (AVNFH) typically constitutes 5 to 15% of all complications of low-energy femoral neck fractures, and due to an increasingly ageing population and a rising prevalence of femoral neck fractures, the number of patients who develop AVNFH is increasing. However, there is no consensus regarding the relationship between blood lipid abnormalities and postoperative AVNFH. The purpose of this retrospective study was to investigate the relationship between blood lipid abnormalities and AVNFH following the femoral neck fracture operation among an elderly population.

Methods

A retrospective, comparative study was performed at our institution. Between June 2005 and November 2009, 653 elderly patients (653 hips) with low-energy femoral neck fractures underwent closed reduction and internal fixation with cancellous screws (Smith and Nephew, Memphis, Tennessee). Follow-up occurred at 1, 6, 12, 18, 24, 30, and 36 months after surgery. Logistic multi-factor regression analysis was used to assess the risk factors of AVNFH and to determine the effect of blood lipid levels on AVNFH development. Inclusion and exclusion criteria were predetermined to focus on isolated freshly closed femoral neck fractures in the elderly population. The primary outcome was the blood lipid levels. The secondary outcome was the logistic multi-factor regression analysis.

Results

A total of 325 elderly patients with low-energy femoral neck fractures (AVNFH, n = 160; control, n = 165) were assessed. In the AVNFH group, the average TC, TG, LDL, and Apo-B values were 7.11 ± 3.16 mmol/L, 2.15 ± 0.89 mmol/L, 4.49 ± 1.38 mmol/L, and 79.69 ± 17.29 mg/dL, respectively; all of which were significantly higher than the values in the control group. Logistic multi-factor regression analysis showed that both TC and LDL were the independent factors influencing the postoperative AVNFH within femoral neck fractures.

Conclusions

This evidence indicates that AVNFH was significantly associated with blood lipid abnormalities in elderly patients with low-energy femoral neck fractures. The findings of this pilot trial justify a larger study to determine whether the result is more generally applicable to a broader population.

Effects of osteoprotegerin, RANK and RANKL on bone destruction and collapse in avascular necrosis femoral head

Avascular necrosis of femoral head (AVFH) is a clinically recalcitrant disease of hip that leads to joint destruction. Osteoprotegerin (OPG), receptor activator of nuclear factor kappa-B (RANK) and RANK ligand (RANKL) regulates the balance, maturation and function of osteoclast and bone remodeling. This study aims to investigate molecular pathways which leads to AVN by studying expression profile of OPG, RANK and RANKL genes. Quantitative Real Time-PCR is used to evaluate mRNA expression of OPG, RANK and RANKL. mRNA and protein level in normal and necrotic tissue from 42 samples of ANFH specimens were analyzed. OPG and RANKL protein levels are estimated by western blotting. The results indicated that OPG mRNA levels are higher but not significantly different in necrotic tissue than that in normal tissue (P>0.05). Although expression of RANK and RANKL is significantly lower than that of OPG, RANK and RANKL mRNA levels are higher in necrotic tissue than normal tissue (P<0.05). Protein levels of OPG and RANKL show no significant difference. In conclusion, OPG, RANK and RANKL play important role in progress of bone remodeling in necrotic area and in disturbance of bone homeostasis, which might have an effect on bone destruction and subsequent collapse of hip joint.

Alterations of sympathetic nerve fibers in avascular necrosis of femoral head

OBJECTIVES

Avascular necrosis of the femoral head (ANFH) was mainly due to alterations of bone vascularity. And noradrenaline (NA), as the neurotransmitter of the sympathetic nervous system (SNS), leads to the vasoconstriction by activating its α-Receptor. This study was to explore the nerve fiber density of the femoral head in the rabbit model of ANFH.

METHODS

Twenty New Zealand white rabbits were used in this study. The rabbit model of ANFH was established by the injection of methylprednisolone acetate. The nerve fiber density and distribution in the femoral head was determined using an Olympus BH2 microscope.

RESULTS

Significant fewer sympathetic nerve fibers was found in the ANFH intertrochanteric bone samples (P = 0.036) with osteonecrosis. The number of sympathetic nerve fibers was compared between the two groups. And less sympathetic nerve fibers were found in later stage ANFH samples in comparison with those of early stages.

CONCLUSIONS

ANFH might be preceded by an inflammatory reaction, and an inflammatory response might lead to arthritic changes in tissue samples, which in turn reduces the number of sympathetic nerve fibers.

Osteonecrosis of the femoral head in childhood malignancy

PURPOSE

Children undergoing chemotherapeutic treatment of malignancies have up to a 9 % incidence of osteonecrosis. The purpose of this article is to determine the time from initiation of chemotherapy to the onset of symptoms and the diagnosis of osteonecrosis of the femoral head in this patient population.

METHODS

A retrospective review of the records of 18 patients (29 hips) under 21 years of age with both a diagnosis of osteonecrosis of the femoral head and childhood onset malignancy was undertaken to determine the time from initiation of chemotherapy to the onset of symptoms and diagnosis of osteonecrosis of the femoral head.

RESULTS

Mean time from initiation of chemotherapy to the onset of pain was 18.8 months (8.0-49.1). The mean time from development of pain to diagnosis of osteonecrosis was 3.9 months (-13.1 to 25). The mean overall time from initiation of chemotherapy to diagnosis of osteonecrosis was 22.7 months (9.0-54.1). 11/18 patients had bilateral disease. 16/18 patients (21/29 hips) had already progressed to stage 4 osteonecrosis at the time of diagnosis.

CONCLUSIONS

There was a high incidence of stage 4 or greater osteonecrosis at the time of diagnosis. Providers caring for these patients should be aware of the potential for osteonecrosis, and the need for prompt diagnosis and referral to an orthopedic surgeon. Screening with advanced imaging studies may be warranted for children undergoing chemotherapeutic regimens for childhood malignancy to prevent delay in the diagnosis and management of this process so that joint preservation therapies remain an option.