Osteonecrosis of the femoral head, nonunion and potential risk factors in Pauwels grade-3 femoral neck fractures: A retrospective cohort study

The present study was to analyze clinical outcome of Pauwels grade-3 femoral neck fractures treated by different surgical techniques. Potential risk factors associated with nonunion and osteonecrosis of the femoral head (ONFH) were investigated as well. The retrospective study comprised of 67 sequential patients treated between January 2008 and December 2011. Patients with Pauwels grade-3 femoral neck fractures were treated by operative reduction and internal fixation. Cannulated screws (CS) were used in 46 patients, dynamic hip screw plus CS (DHS+CS) in 14, and locking compression plate (LCP) for proximal femur in 7. Reduction quality was assessed according to Haidukewych criteria. Postoperative radiographic examinations were conducted to observe fracture healing. Fracture displacement, comminution, fashion of internal fixation, and the sliding effect were analyzed, regarding the incidence of nonunion and ONFH. All patients had a follow-up of 21.6 ± 6.0 months on average. The phenomenon of sliding effect was observed in 16 cases (23.9%). In terms of reduction quality, 64 cases were graded as excellent, 2 were good, and 1 was poor. ONFH was presented in 15 cases (22.4%) and nonunion was found in 8 (11.9%), with 1 patient had ONFH and nonunion concomitantly. Profound hip contour was preserved in 45 cases (67.2%). The fashion of internal fixation yielded different results regarding ONFH and nonunion, whereas the effects of fracture displacement, comminution, and the sliding effect were not significant. ONFH and nonunion were common complications following Pauwels grade-3 femoral neck fractures. Higher incidence of ONFH in DHS+CS and of nonunion in the LCP group should be noted.

TLR4 stimulation and corticosteroid interactively induce osteonecrosis of the femoral head in rat

We previously reported that a toll-like receptor 4 signaling contributes to the development of osteonecrosis of the femoral head. Also, oxidative stress is suggested to be one of the possible pathogenesis of osteonecrosis of the femoral head. A recent study showed that toll-like receptor 4 signaling leads to oxidative stress. The aim of the present study was to evaluate whether toll-like receptor 4 stimulation and subsequent corticosteroid treatment lead to the development of osteonecrosis of the femoral head in rat, and oxidative stress is associated with it. Male Wistar rats were randomly divided into four treatment groups: Saline + Saline, Saline + Methylprednisolone, Lipopolysaccharide + Saline, Lipopolysaccharide + Methylprednisolone. Osteonecrosis of the femoral head at 14 days after the treatment was observed in 1 of 10 Lipopolysaccharide + Saline, and 5 of 10 Lipopolysaccharide + Methylprednisolone treated rats. However, it was not observed at all in the Saline + Saline and Saline + Methylprednisolone treated groups. Glutathione peroxidase activity in the liver at 1 day after the treatment was significantly increased when treated with lipopolysaccharide. However, methylprednisolone treatment reduced the activity. On the other hand, glutathione peroxidase activity in the femur did not change in any intergroup. In conclusion, the present study showed that toll-like receptor 4 stimulation by lipopolysaccharide administration strengthen incidence of corticosteroid-induced osteonecrosis of the femoral head, however, concomitant oxidative stress via toll-like receptor 4 signaling may not contribute to the development of osteonecrosis of the femoral head in rats.

Total hip arthroplasty after failed curved intertrochanteric varus osteotomy for avascular necrosis of the femoral head

Curved intertrochanteric varus osteotomy (CVO) is one of the good surgical procedures for avascular necrosis of the femoral head (ANFH) patients. However, some patients with failed CVO are converted to total hip arthroplasty (THA) as a salvage operation. We compared the clinical and radiographic outcomes of 10 hips converted to THA after failed CVO (Group O) (mean age 43.0 years, 8 male and 2 female) with an age and gender matched control group of 20 hips that underwent primary THA for ANFH (Group C). Perioperative blood loss in Group O was significantly higher than that in Group C (535 g vs 282 g (P = 0.002)). Infection and dislocation occurred in 1 and 2 hips in Group O. There were no significant differences in both pre- and post-Harris Hip Score (HHS) between the groups. The stems in the AP radiograph were placed at 2.1° in a valgus position in Group O, whereas those in Group O were inserted at 1.0° in a varus position, a significant difference (P = 0.01). The stem alignment in the Lauenstein view in Group O was 1.2° in the extension position and in Group C was 0.4° in the flexion position, a significantly difference (P = 0.04). THA after failed CVO provides with the stem inserted in a valgus and extension position. Operative bleeding was increased. THA after failed CVO is a technically demanding arthroplasty. We believe that careful preoperative planning and preparation are necessary for this arthroplasty.

Core decompression or quadratus femoris muscle pedicle bone grafting for nontraumatic osteonecrosis of the femoral head: A randomized control study

BACKGROUND

The traditional management for osteonecrosis of the femoral head (ONFH) includes core decompression (CD) and quadratus femoris muscle pedicle bone graft (QF-MPBG). The aim of this study was to investigate the effects of CD and QF-MPBG on the patients with nontraumatic ONFH in an early stage.

MATERIALS AND METHODS

39 patients (47 hips) with ONFH in an early stage (Ficat Stage I or II) were randomly divided into two groups according to random number table method. One group was treated with CD and cancellous bone grafting. Another group was treated QF-MPBG with cancellous bone grafting. The hip function was evaluated using Harris hip score (HHS). The repair of the femoral head was estimated through X-ray, computed tomography (CT), or magnetic resonance imaging (MRI). The surgical time and intraoperative blood loss was calculated.

RESULTS

All patients were followed for an average 2.5 years (range from 1.5 to 4 years). Two hips in CD group progressed into stage 3 and three hips in QF-MPBG group processed into stage 3. No patient accepted the THA at the last followup. The HHSs significantly increased in both groups after surgery (P < 0.05). No statistical differences were found between CD and QF-MPBG groups in postoperative HHSs at last followup (P > 0.05). X-ray and CT showed that the femoral head did not progress to collapse after operation in both groups. In addition, MRI showed that the edema signals decreased. However, the surgical time was longer in QF-MPBG group than that in CD group (P < 0.05). The intraoperative blood loss was more in QF-MPBG than that in CD group (P < 0.05).

CONCLUSION

The CD with bone graft could relieve hip pain, improve hip function with much lesser surgical trauma compared to QF-MPBG. Hence, the CD with bone graft should be generally used for the treatment of patients with an early stage (Ficat Stage I or II) ONFH.

Relation between osteonecrosis of the femoral head and PAI-1 4G/5G gene polymorphism: a meta-analysis

OBJECTIVE

The aim of this study was to investigate the association of plasminogen activator inhibitor-1 (PAI-1) 4G/5G gene polymorphism and osteonecrosis of the femoral head (ONFH).

METHODS

The pooled relative risk ratio (RR) and 95% confidence intervals (95% CI) were calculated using the the RevMan 5.0 software.

RESULTS

The present study included 969 patients with ONFH and 419 healthy controls. The Meta analysis results showed: There is association between PAI-1 gene 4G/5G polymorphism and the increasing risk of ONFH (allele model: RR = 1.24, 95% CI = 1.16 ~ 1.33; dominant genetic model: RR = 1.12, 95% CI = 1.05 ~ 1.18). It was found that the association between PAI-1 gene 4 G/5 G polymorphism and the susceptibility of ONFH (P < 0.05) through the comparison of Caucasian population and Asian people according to the analysis of different races.

CONCLUSIONS

There is association between PAI-1 gene 4 G/5 G polymorphism and the increasing of the susceptibility of ONFH.

Review of various treatment options and potential therapies for osteonecrosis of the femoral head

Size and location of the lesion, subchondral collapse occurrence, and articular cartilage involvement are general disease progression criteria for direct osteonecrosis of the femoral head (ONFH) classifications. Treatment options for ONFH are usually based on individual factors and lesion characteristics. Although spontaneous repair of ONFH occurs in some cases, untreated ONFH is unlikely to escape the fate of subchondral collapse and usually ends up with total hip arthroplasty. Operations to preserve the femoral head, e.g., core decompression and bone grafting, are usually recommended in younger patients. They are helpful to relieve pain and improve function in the affected femoral head without subchondral collapse, however, poor prognosis after surgical procedures remains the major problem for ONFH. Pharmacological and physical therapies only work in the early stage of ONFH and have also been recommended as a supplement or prevention treatment for osteonecrosis. Following advances in basic science, many new insights focus on bone tissue engineering to optimize therapies and facilitate prognosis of ONFH. In this review, disease classifications, current treatment options, potential therapies, and the relevant translational barriers are reviewed in the context of clinical application and preclinical exploration, which would provide guidance for preferable treatment options and translation into novel therapies.

Association between VEGF -634G/C polymorphism and osteonecrosis of the femoral head susceptibility: a meta analysis

BACKGROUND

VEGF plays an important role in bone formation and repair. However, the effects of VEGF -634G/C polymorphisms on the pathogenesis of osteonecrosis of the femoral head (ONFH) were not conclusive. Our research was aimed to further analyze the association of VEGF -634G/C polymorphism with ONFH risk.

METHODS

The relevant articles were searched in PubMed, Elsevier, EMBASE, Web of Science and Chinese National Knowledge Infrastructure (CNKI) database. And a total of 692 cases and 875 controls were included. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated to assess the correlation of VEGF -634G/C polymorphism and ONFH susceptibility. Chi-square based Q-statistic test was used to evaluate heterogeneity among the studies. The random-effects model or fixed-effects model was used depending on heterogeneity.

RESULTS

The sensitivity analysis and publication bias test indicated that our results were stable and credible. And the results suggested that VEGF -634G/C polymorphism was significantly related with increased risk for ONFH in Asian population (CC versus GG: OR=1.34, 95% CI=1.02-1.76).

CONCLUSION

The results indicated that VEGF -634G/C polymorphism might serve as genetic-susceptibility factor for ONFH.

Icariin: A promising osteoinductive compound for repairing bone defect and osteonecrosis

Icariin (Ica), the main active component of Herba Epimedii, has been identified as an osteogenic and angiogenic phytomolecule. To develop a bioactive scaffold for enhancing bone repair, Ica was loaded into porous tricalcium phosphate (TCP) scaffolds, and the obtained porous Ica/TCP composites were investigated for treating osteonecrosis of the femoral head (ONFH) in a rabbit model. ONFH was histopathologically confirmed at two weeks after methylprednisolone acetate injection, and the rabbits were treated with porous Ica/TCP scaffolds (group A), porous TCP scaffolds (group B), and autogenous cancellous bone graft (group C). At 12 weeks, the amount of newly formed bone in group A increased significantly compared with that in group B (P = 0.003). The mean histological and radiological scores for repaired defects in group A were significantly higher than those in group B (P = 0.007, P = 0.029, respectively), but were lower than those in group C (P = 0.032, P = 0.046, respectively). In addition, the expression of vascular endothelial growth factor by immunohistochemical testing and real-time polymerase chain reaction in group A was significantly higher than that in group B (P = 0.002, P = 0.001, respectively), but was lower than that in group C (P = 0.034, P = 0.005, respectively). Therefore, Ica can be a promising osteogenic and angiogenic compound for repairing bone defects and preventing the collapse of the femoral head in ONFH.

Combined effect of tnf-α polymorphisms and hypoxia on steroid-induced osteonecrosis of femoral head

OBJECTIVE

Tumor necrosis factor (TNF)-α is a proinflammatory cytokine, some studies reported that TNF-α gene plays important role in the pathogenesis of SONFH. And the polymorphisms of TNF-α were presented as risk factors for steroid-induced osteonecrosis of the femoral head (SONFH). Meanwhile, various environment factors involve in the pathogenesis of SONFH. Our study aimed to investigate the interaction effect of TNF-α polymorphisms and hypoxia factor on SONFH.

METHODS

120 patients with SONFH and 100 healthy people, matched with the cases on age and sex, participated in this study. DNA was extracted from all participants. According to previous studies, genotyping of TNF-α polymorphisms (rs1800629, rs1799964 and rs1800630) was tested with the method of PCR-RDB (Reverse Dot Blot). Environmental factors were also chose. Logistic regression analysis was used to analyze the interaction between TNF-α polymorphisms and environment factors on SONFH.

RESULTS

The polymorphisms of rs1800629 and rs1800630 were significantly associated with SONFH (OR: 3.70, 9.93). Patients with hypoxia history were found higher (65.00%) compared with the healthy controls (43.00%). For the person with hypoxic history, GG and AG+AA genotypes of rs1800629 could increase their risk to suffer SONFH (OR: 2.12, 3.78). If the patients with the variant genotypes of rs1800630 experienced hypoxia state, then the risk for SONFH increased 2.41 folds.

CONCLUSION

We concluded that the onset of SONFH was influenced by TNF-α and hypoxia history. There existed strong interaction between TNF-α and hypoxia history.

Osteonecrosis of the femoral head with collapsed medial lesion

A 60-year-old female experienced the gradual onset of left hip pain without any triggering event. Radiographs showed vertical sclerosis in the center of the femoral head and the lesion inside the boundary demonstrated diffuse bony sclerosis. No collapse was observed at the weight-bearing portion on radiograph. However, computed tomography showed a subchondral collapse at the medial lesion. On T2-weighted magnetic resonance imaging, the necrotic lesion showed diffuse high-intensity signals that indicated a prominent repair process. Bone biopsy diagnosed osteonecrosis with associated prominent appositional bone and vascular granulation tissue.

Cajan leaf combined with bone marrow-derived mesenchymal stem cells for the treatment of osteonecrosis of the femoral head

The aim of the present study was to observe the curative effect of traditional Chinese cajan leaves, combined with administration of bone marrow-derived mesenchymal stem cells (BMSCs), on osteonecrosis of the femoral head (ONFH) in rats and to investigate the underlying mechanisms. A total of 40 rat ONFH models were established through liquid nitrogen freezing and were subsequently divided into groups: A, control; B, treated with cajan leaf; C, treated with BMSCs and D, treated with cajan leaf combined with BMSCs. Samples were obtained 30 days following treatment, and immunohistochemical staining of vascular endothelial growth factor (VEGF) and image analysis were performed. Chondrocytes and vascular endothelial cells were stained as a result of immunohistochemical staining and group D exhibited markedly deeper staining, and a significantly larger number of stained cells, compared with group A. Thus, in the present study, cajan leaf combined with BMSCs was shown to promote VEGF expression and improve ONFH repair.

Conversion total hip arthroplasty after previous transtrochanteric rotational osteotomy for osteonecrosis of the femoral head

The results of conversion total hip arthroplasty (THA) after failed transtrochanteric rotational osteotomy (TRO) are still controversial. We retrospectively reviewed 18 patients with ONFHs who had been treated previously by TRO and were later converted to THAs (conversion group). We made a matched control group of 18 primary THAs for ONFH done by same hip surgeon (PTHA group). There was an improvement in the Harris hip score and WOMAC score at the final follow-up but the improvement was not statistically significant between the two groups. Only internal rotation was significantly better in the PTHA group than in the conversion group. THA after TRO provides satisfactory clinical and radiological outcomes with no significant increase in perioperative morbidity in comparison with that in the primary THA.

Biophysical stimulation in osteonecrosis of the femoral head

Osteonecrosis of the femoral head is the endpoint of a disease process that results from insufficient blood flow and bone-tissue necrosis, leading to joint instability, collapse of the femoral head, arthritis of the joint, and total hip replacement. Pain is the most frequent clinical symptom. Both bone tissue and cartilage suffer when osteonecrosis of the femoral head develops. Stimulation with pulsed electromagnetic fields (PEMFs) has been shown to be useful for enhancing bone repair and for exerting a chondroprotective effect on articular cartilage. Two Italian studies on the treatment of avascular necrosis of the femoral head with PEMFs were presented in this review. In the first study, 68 patients suffering from avascular necrosis of the femoral head were treated with PEMFs in combination with core decompression and autologous bone grafts. The second one is a retrospective analysis of the results of treatment with PEMFs of 76 hips in 66 patients with osteonecrosis of the femoral head. In both studies clinical information and diagnostic imaging were collected at the beginning of the treatment and at the time of follow up. Statistical analysis was performed using chi-square test. Both authors hypothesize that the short-term effect of PEMF stimulation may be to protect the articular cartilage from the catabolic effect of inflammation and subchondral bone-marrow edema. The long-term effect of PEMF stimulation may be to promote osteogenic activity at the necrotic area and prevent trabecular fracture and subchondral bone collapse. PEMF stimulation represents an important therapeutic opportunity to resolve the Ficat stage-I or II disease or at least to delay the time until joint replacement becomes necessary.