A modified surgical method for the treatment of ONFH: quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular artery.

BACKGROUND: Osteonecrosis of the femoral head (ONFH) can lead to pain and loss of function of the hip joint, which places a great burden on patients and society. Surgery is the main treatment for osteonecrosis of the femoral head, and quadratus femoris muscle pedicle bone grafting has a definite therapeutic effect as one method of surgery for the treatment of ONFH. However, the posterior superior retinacular artery is often injured during quadratus femoris muscle pedicle bone graft surgery. There is evidence that this artery is extremely important to the femoral head, as injury to this artery will seriously affect the blood supply of the femoral head. Therefore, this situation restricts the clinical application of quadratus femoris muscle pedicle bone grafts. We aimed to explore a new surgical method of quadratus femoris muscle pedicle bone grafting that can preserve the integrity of the posterior superior retinacular artery. METHODS: We modified the traditional quadratus femoris muscle pedicle bone graft and preserved the integrity of the posterior superior retinacular artery. To explore the safety and feasibility of the operation, we simulated the operation on 6 fresh frozen cadavers (12 hips) and measured the related data. We also tried this modified surgical method in the clinic and collected detailed data from the patients. RESULTS: By simulating the modified quadratus femoris muscle pedicle bone graft on the hip joints of fresh frozen cadavers, we found that the posterior superior retinacular artery existed in all cadaver specimens and that the sources may be different (MFCA or IGA). In the modified operation, the joint capsule did not need to be cut during the operation; therefore, the integrity of the posterior superior retinacular artery was preserved. The quadratus femoris muscle was exposed via the posterior approach of the hip joint, and then the quadratus femoris muscle pedicle bone flap was chiseled. After the pedicle of the quadratus femoris muscle was loosened properly, the migration distance of the quadratus femoris muscle pedicle bone flap reached 5.89 ± 0.45 (χ ± s) cm. The bone flap was trimmed properly and placed on one side. Next, we drilled a bone tunnel from the external intertrochanteric aspect of the capsule of the hip joint, and the bone tunnel broke through the sclerosing zone and proceeded straight to the necrotic area of the femoral head. Next, the necrotic bone was removed with a ring saw and arc bone knife, autogenous bone or allogeneic bone was filled into the bone groove according to the situation, and the cancellous bone in the bone groove was tamped by percussion. Then, the bone flap was inserted into the bone groove, and appropriate pressurization was performed. The depth of the bone groove was determined by the location of ONFH. We found that the furthest distance between the bone groove and the femoral head was 4.76 ± 0.07 (χ ± s) cm and that the length of the bone flap was (4.91 ± 0.23) (χ ± s) cm. This means that when the depth of the bone groove reached the area of ONFH, the quadratus femoris muscle pedicle bone flap had a sufficient length and migration distance to be embedded in the area of ONFH and firmly fixed, and the quadratus femoris did not have much tension. The closest distance between the posterior superior retinacular artery and the bone groove was (1.11 ± 0.96) (χ ± s) cm. When the bone groove was created in this area, the edge of the bone groove had a safe distance of at least 1 cm from the posterior superior retinacular artery of the femoral head. We attempted to implement this modified operation clinically. During the procedure, the quadratus femoris muscle pedicle bone flap was embedded into the drilled bone groove and fixed with a magnesium nail. There was no sliding of the bone flap after the operation, and the posterior superior retinacular artery was intact. We followed the patient for 3 months and found that the patient recovered well with no weight-bearing by the affected limb. The duration of the modified operation was shorter than that of the traditional quadratus femoris muscle pedicle bone graft, the amount of bleeding was significantly reduced, the postoperative pain was lessened, and no special discomfort was reported. Postoperative imaging examination showed that the collapse of the femoral head had been partially corrected and that the bone flap had gradually fused with the surrounding bone. CONCLUSIONS: Through this experimental study, we confirmed the feasibility of the modified method for quadratus femoris muscle pedicle bone grafting with preservation of the posterior superior retinacular artery. This modified operation not only retains the integrity of the posterior superior retinacular artery of the femoral head but also reduces the difficulty of the operation and shortens the surgical time, which is of great clinical significance.

The effects of phthalate and nonylphenol exposure on body size and secondary sexual characteristics during puberty.

BACKGROUND: Some phthalic acid esters (PAEs) and nonylphenol (NP) are endocrine-disrupting chemicals (EDCs) that are widely used in consumer products. Consequently, the general population is exposed simultaneously to both groups of chemicals. OBJECTIVE: To investigate the single- and co-exposure effects of PAEs (DMP, DEP, DnBP, DiBP, BBzP, and DEHP) and NP on obesity and pubertal maturity to compare the body sizes of general adolescents with the complainants of the phthalate-tainted foods scandal that occurred in Taiwan. METHODS: This study included 270 general adolescents aged 6.5-15.0 years and 38 complainants aged 6.5-8.5 years. Nine metabolites of the five PAEs and of NP were measured in urine. We used a questionnaire to evaluate pubertal maturity, measured anthropometric indices (APs) to assess body size, and collected urine samples to measure the two groups of chemicals. RESULTS: We found that urinary PAE metabolite concentrations (specifically, metabolites of DEP, DnBP, DiBP, and DEHP) were positively associated with the APs for abdominal obesity (including skinfold thickness, waist circumference, waist-to-height ratio, and waist-to-hip) and indicated a dose-response relationship. Mono-methyl phthalate (MMP) exposure was inversely associated with pubarche among boys. The daily intake of DEHP in general adolescents exceeded the reference doses (RfD-20 µg/kgbw/day) and tolerable daily intake (TDI-50 µg/kgbw/day) by 3.4% and 0.4%, respectively. No associations were observed between NP exposure or co-exposure and the APs or pubertal maturity. No significant differences were observed between general adolescents and the complainants with regard to weight, height, or BMI. CONCLUSIONS: The study suggests that PAE (specifically, DEP, DnBP, DiBP, and DEHP) exposure is associated with abdominal obesity in adolescents and that the APs for abdominal obesity are more sensitive than BMI for measuring obesity among adolescents. We suggest that the RfD and TDI for PAEs should be revised to provide sufficient protection.