Avascular Osteonecrosis of the Talus: Current Treatment Strategies

Avascular osteonecrosis (AVN) of the talus (AVNT) is a painful and challenging clinical diagnosis. AVNT has multiple known risk factors and etiologies and presents at different stages in severity. Given these unique factors, the optimal treatment solution has yet to be determined. Both joint-preserving and joint-sacrificing procedures are available, including core decompression and arthrodeses. Recently, new salvage and replacement techniques have been described including vascularized pedicle bone grafts and total talus replacement using patient-specific prosthesis; however, evidence remains limited. This review examines the current trends AVNT treatment and the emerging data behind these novel techniques.

Association of MTHFR rs1801133 and Homocysteine With Legg-Calvé-Perthes Disease in Mexican Patients

Background: Legg-Calvé-Perthes disease (LCPD) is an avascular osteonecrosis of the femoral epiphysis. It is a rare disease of unclear etiology in children. Alterations in coagulation, or the collagen gene have been described and could be associated with its etiology. Therefore, we set out to evaluate the following alterations: COL1A1 (rs1107946, rs2412298), COL2A1 (rs121912891 and rs387106558), MTHFR rs1801133, CBS rs115742905, and PT rs1799963 and their relationship with LCPD.Methods: DNA was obtained and genotyped by real-time PCR with TaqMan probes. It was determined prothrombin and homocysteine (Hcy) by a coagulometric method. The variables were described as mean and standard deviation or percentages, and genotypic and allelic distributions were analyzed using the Student's t-test. In addition, the Hardy-Weinberg equilibrium, and OR.Results: We studied 23 patients with LCPD and 46 controls. We did not find any association of the MTHFR, CBS, PT, COL1A1, and COL2A1 genetic variants with LCPD. However, when adjusting the data with the Hcy values for the MTHFR C677T polymorphism, the C/C genotypes showed an association with the recessive model (p = 0.038) with susceptibility to LCPD.Conclusion: No association was found with the CBS, PT, COL1A1, and COL2A1 genes. Nevertheless, our results suggest a significant link between moderately elevated Hcy levels and the MTHFR C677T polymorphism in a cohort of Mexican children with LCPD.

Serum Insufficiency Induces RANKL-Independent Osteoclast Formation during Developing Ischemic ONFH

Blood supply interruption induces hypoxia and reduces serum provision to cause ischemia-induced osteonecrosis, including avascular osteonecrosis of the femoral head (ONFH). Oxygen deficiency (hypoxia) is known to induce different expression patterns in osteoblasts and osteoclasts, which have been extensively studied. However, the effects of serum insufficiency in nutrients, growth factors, and hormones on osteoblast and osteoclast activity in the damaged area and nearby regions remain poorly understood. In this study, the expression of osteoblast and osteoclast marker proteins was elucidated through in vitro and ex vivo studies. The results indicate that serum insufficiency accelerates the formation of monocyte-derived osteoclasts. The combined effect of serum insufficiency and hypoxia (mimicking ischemia) suppressed the activity of alkaline phosphatase and calcification in osteoblasts after the stimulation of osteogenic growth factors. Serum insufficiency increased the activity of tartrate-resistant acid phosphatase, expression of phosphorylated extracellular signal-regulated kinases, and production of reactive oxygen species in monocyte-derived osteoclasts in the absence of receptor activator of nuclear factor kappa-Β ligand stimulation. The findings indicate that changes in the expression of osteoblast and osteoclast markers in necrotic bone extracts were similar to those observed during an in vitro study. These results also suggest that serum insufficiency may be involved in the regulation of osteoclast formation in patients with ONFH.

Comparison of the Effects of Two Different Hollow Nails in the Treatment of the Young Pauwels Type Ⅲ Femoral Neck Fractures

Background: At present, there is a higher complication rate after treatment of femoral neck fractures with three parallel hollow nails (PHN) in the young Pauwels type Ⅲ femoral neck fractures.For better effect,F-shape hollow nails(FHN) is used to treat femoral neck fractures.The purpose of this study is to compare the clinical efficacy of FHN and PHN and provide reference for clinical application.Methods: Thirty-eight consecutive patients admitted from January 2017 to January 2020 were selected for the study. According to random number table method, the patients were divided into two groups:group A (FHN) and group B (PHN). The gender, age, BMI, comorbidities, time from injury to operation and other general preoperative demographics were not statistically different (P>0.05). The data of the two groups can be comparable.The occurrence of avascular osteonecrosis of the femoral head (AVN), femoral neck shortening, hollow screw withdrawal was recorded in follow-up.Then, Harris hip score (HHS), pain visual analog score (VAS) of two group were obtained at the last follow-up. Results: The mean follow-up period after surgery was 21.4±10.1 (range, 14–29) months. There were 18 cases(mean age, 47.5±9.6) in group A, 20 cases (mean age, 48.6±10.1) in group B. There was no significant difference between the two groups in AVN, femoral neck shortening (P>0.05), the two groups had statistically significant differences in screw withdrawal (F=4.416, P<0.05). There was no significant difference in HHS and VAS between the two groups at the last follow-up (P>0.05).Conclusion: Three parallel hollow nails (PHN) and F-shape hollow nails (FHN) have similar short-term effects in the young Pauwels type Ⅲ femoral neck fractures, but the nail withdrawal rate of FNH is lower.

Splay Toe after Freiberg-Köhler’s Osteonecrosis: A Case Report of a Successful Operative Treatment in a Rare Multiplanar Foot Deformity

“Splay toe” is a rare deformity of the forefoot and often causes the occurrence of metatarsalgia and dysfunction while walking or weight bearing. Since it involves a deviation in the sagittal and transversal planes, often combined with a malrotation, surgical correction can be challenging. We describe a case of splay toe deformity in the forefoot causing metatarsalgia in a 62-year-old female patient with a former avascular osteonecrosis of the 2 metatarsal head Smillie stage V of Freiberg-Köhler’s disease causing a splay toe between the 2nd and the 3rd rays. There are only few reports in the literature, and a clear treatment strategy has not been defined, yet, although, it has been described that most of these patients are operated more than once. In the presented case, we performed a successful treatment by a combined surgical technique consisting in modified Weil’s osteotomy and the transfer of the extensor brevis tendon. We sustain that for correction of a multiplanar deformity of lesser toe deformities osseous correction as well as tendon transfer lead to successful therapy.