Bone morphology and physical characteristics of the pro-cyclist hip joint.

PURPOSE: This study aimed to investigate the radiographic findings for the hip joint and hip range of motion in professional cyclists, and to determine their bone morphology and physical characteristics. The effects of physical characteristics on athletic performance were examined in terms of metabolic efficiency using simulation analysis. METHODS: We performed a case-control research study on 22 hips in 11 male professional cyclists (average age 28.5, height 1.73 m, weight 77.6 kg). Thirty hips in 15 healthy male volunteers were selected as controls. As radiographic evaluations, acetabular dysplasia was assessed on standardized radiographs. During physical evaluations, the hip range of motion was examined. We used simulation analysis to investigate the metabolic efficiency in the different cycling forms. RESULTS: The radiographic evaluations showed a significant difference in the incidence of acetabular dysplasia (p = 0.01): 59% (13/22 hips) in the pro-cyclist group versus 10% (3/30 hips) in the control group. The physical evaluations revealed significant differences in the hip internal rotation angle (p = 0.01), with greater ranges of internal rotation in the pro-cyclist group versus the control group. The simulation analyses showed that metabolism was reduced in the cycling form with hip internal rotation, especially in the lower extremities. CONCLUSIONS: Pro-cyclists showed a high frequency of acetabular dysplasia and superior hip internal rotation. According to the cycling model analyses, hip internal rotation allowed pedaling with reduced metabolic power.

Effects of lateral circumflex femoral artery ligation on blood flow to the surrounding muscles in the direct anterior approach.

BACKGROUND: The direct anterior approach to the hip joint enables the identification and ligation of the lateral circumflex femoral artery. However, the effect of lateral circumflex femoral artery ligation on blood flow to the muscles surrounding the hip remains unknown. This study clarified the changes in blood flow to the surrounding muscles following ascending branch ligation of this artery. METHODS: We included 36 consecutive patients (8 male and 28 female) who underwent total hip arthroplasty via the direct anterior approach for hip osteoarthritis between April 2015 and July 2016. The intraoperative blood flow to the tensor fascia latae (TFL), vastus lateralis (VL), rectus femoris (RF), and subcutaneous tissue (control) was measured using a laser Doppler blood flow meter. Measurements were repeated after artery ligation and at the end of surgery. We compared the means (±SD) of these measurements at each location and time point. RESULTS: The patients' mean age was 64.2 ± 9.0 years, systolic and diastolic blood pressures were 92.8 ± 13.6 and 54.9 ± 9.1 mmHg, respectively, and body mass index was 23.1 ± 3.9 kg/m2. Hypertension was noted in 35.9% patients and dyslipidemia in 27.8%. The mean surgical duration was 101 (70-158) min. The preligation blood flow in TFL, VL, RF, and subcutaneous tissue was 3.91 ± 1.93, 5.15 ± 2.19, 4.51 ± 2.24, and 3.03 ± 0.99 mL/min/100 g, respectively. CONCLUSIONS: Blood flow to TFL significantly decreased post ligation and at the end of surgery. However, there was no change in blood flow to VL and RF.

The prevalence and risk factors for delayed union of the superior pubic ramus at one year after curved periacetabular osteotomy: its risk factor and outcome.

PURPOSE: Curved periacetabular osteotomy (CPO) has been developed for the treatment of acetabular dysplasia. While several studies have reported its good clinical results, the complications of CPO include delayed union and nonunion of the superior pubic ramus. The purpose of this study is to investigate the prevalence of delayed union of the pubis one year after CPO, and to determine the risk factors for this complication. METHODS: The study examined 113 hips that underwent CPO between 2008 and 2012. Delayed union was assessed based on the anteroposterior radiography one year after CPO. A superior pubic ramus union group (U group) and a delayed union group (D group) were retrospectively compared regarding patient characteristics, clinical evaluations, and radiographic parameters. RESULTS: Delayed union rate was 16.8%. The D group contained a significantly greater proportion of smokers (p < 0.001). The gap at the pubic osteotomy site on CT coronal images was significantly larger in the D group (p < 0.001), and the cut-off value for the risk of nonunion was larger than 5.1 mm. Multivariate regression analysis indicated that smoking (OR 10.7, 95% CI 2.1-55.4) and a gap at the superior pubic ramus >5.1 mm (OR 16.5, 95% CI 3.7-73.7) were significantly associated with delayed union as independent risk factors. CONCLUSION: The prevalence of delayed union one year after CPO was 16.8%. Smoking and a gap larger than 5.1 mm at the pubic osteotomy site are risk factors for delayed union after CPO.

Incidence of delayed union one year after peri-acetabular osteotomy based on computed tomography.

BACKGROUND: Pubic bone nonunion and delayed union are reported as post-operative complications after peri-acetabular osteotomy (PAO). However, few studies have determined the incidence of delayed union using computed tomography (CT) scans. This study aimed to determine the incidence of delayed union at one year after PAO using X-ray and CT scans. METHODS: We performed a retrospective review of 150 hips in 132 consecutive patients with acetabular dysplasia who underwent PAO between January 2012 and June 2016 and evaluated 107 hips for which pelvic CT scans taken at one year after PAO were available. Clinical evaluations included age at surgery, weight, body mass index (BMI) and history. Radiographic evaluations were to assess pubic, ischial and iliac delayed union at one year post-operatively. RESULTS: Based on X-ray analysis, the incidence of delayed union in the pubic, ischial and iliac bones was 11.2% (12 hips), 5.6% (6 hips) and 0% (0 hips), respectively, and20.6% (22 hips), 8.4% (9 hips) and 0% (0 hips), respectively, based on CT scans. CONCLUSION: The incidence of delayed union of the pubis and ischium at one year after PAO according to CT scans was higher than that based on X-ray imaging. CT scans are useful in patients with some symptoms at the osteotomy site. LEVEL OF EVIDENCE: Level III.

The Utility of False-Profile Radiographs for the Detection of Osteoarthritis Progression in Acetabular Dysplasia.

BACKGROUND: Both the lateral center-edge angle and acetabular roof obliquity on anteroposterior radiographs are well-known prognostic predictors of osteoarthritis progression in patients with acetabular dysplasia. However, few studies have evaluated osteoarthritis progression on false-profile radiographs. In the present study, osteoarthritis progression was evaluated on anteroposterior and false-profile radiographs. METHODS: We retrospectively evaluated 76 patients with acetabular dysplasia with Tönnis grade-0 or 1 osteoarthritis, from a group of 179 patients (209 hips), who had undergone unilateral periacetabular osteotomy from 1995 to 2005. We evaluated the hip joint of the contralateral, untreated side. All patients were followed for ≥10 years. Of the 76 patients, 52 patients with Tönnis grade-0 or 1 osteoarthritis at the latest follow-up were categorized into the non-progression group and the remaining 24 patients with Tönnis grade-2 or 3 osteoarthritis were categorized into the progression group. We evaluated patient characteristics as well as radiographic parameters, including the preoperative lateral center-edge angle, acetabular roof obliquity, and anterior center-edge angle. RESULTS: The mean duration of follow-up was 12.6 years (range, 10 to 19 years). On univariate analysis, body weight, body mass index, and all radiographic parameters indicating the severity of acetabular dysplasia significantly differed between the 2 groups. On multivariate analysis, both the anterior center-edge angle and acetabular roof obliquity were considered to be significant predictive factors for osteoarthritis progression. On receiver operating characteristic curve analysis, the cutoff values for the lateral center-edge angle, acetabular roof obliquity, and anterior center-edge angle were 15.5°, 15.5°, and 12.5°, respectively. CONCLUSIONS: In addition to the lateral center-edge angle and acetabular roof obliquity, we showed that the anterior center-edge angle is a possible prognostic predictor of osteoarthritis progression. These findings indicate that radiographic parameters based on the false-profile view are relevant. Additionally, patients with an anterior center-edge angle of ≤12.5° and a lateral center-edge angle of ≤15.5° seem to be at higher risk of osteoarthritis progression over a 10-year period. LEVEL OF EVIDENCE: Prognostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Open pelvic ring fracture and multiple fractures of the lower extremities: a case report.

A 73-year-old female was hit by a car, and transferred to our hospital. On examination, her consciousness was alert, but her vital signs were unstable. There are three 10-cm open wounds on her right buttock. X-rays showed an unstable pelvic ring fracture, a right femoral shaft, a right proximal tibia and a right tibial plafond fractures. One hour after the injury, transarterial embolization (TAE) followed by external fixation (EF), and retroperitoneal pelvic packing (RPP) was performed. Two days and five days after the injury, thorough debridement of the open wounds was performed. The skin defect on the right buttock and the lower abdomen had enlarged to 40 x 35 cm, therefore, negative pressure wound therapy was applied. On the same day, right femur was fixed using a retrograde intramedullary nailing. 12 days after the injury, the proximal tibial fracture was fixed using a plate, and the tibial plafond fracture was fixed using screws and external fixators. 28 days after the injury, the split-thickness skin graft was performed on the right buttock and the lower abdomen. Seven months after the injury, the open wounds were completely healed without infection. She was able to walk smoothly with a T-cane. For the management of open pelvic ring fractures, it is essential to perform TAE, EF and RPP as soon as possible. Providing aggressive management, including thorough debridement, is mandatory to prevent severe infection and sepsis. We achieved a good clinical outcome by using a combination of TAE, EF, RPP and staged surgery, including thorough debridement.