Surface replacement solutions for the arthritic hip

Surface replacement is a conservative treatment for young, active patients with hip osteoarthritis. It provides an increased range of motion as the result of a larger diameter head and improved wear characteristics because of the metal-on-metal articulation as well as an extremely low dislocation rate and increased patient function. While early results are encouraging, long-term outcomes are necessary to define and delineate the role of surface replacement arthroplasty in the treatment of significant hip arthritis.     

Total prosthesis implantation in the arthritic hip

In 11 patients, hip arthrodeses were converted to arthroplasties. The follow-up period ranged from 1 to 21 years. In some cases the patients' own assessment contrasted with the objective findings. No difference could be determined between previously arthrodesed and ankylosed hips. The duration of arthrodesis did not have an influence on the long-term results. It is interesting to note that in this group of patients the long-term survival rate proved to be slightly better than the overall survival rate for all patients with arthroplasties performed in our clinic.     

Hinged distraction of the adolescent arthritic hip

From 1996 to 2000, 11 adolescents with hip joint arthritis secondary to osteonecrosis or idiopathic chondrolysis were treated with articulated hinged distraction arthroplasty. Indications for surgery were severe pain and limited ambulation. Charts and radiographs were reviewed. Clinical status was assessed preoperatively and at latest follow-up (mean 4.8 years after surgery) using criteria of pain, range of motion, and ambulation level. Ten patients showed improved clinical status, with seven having an excellent outcome and three a good outcome. One patient failed distraction. Mean joint space was 2.6 mm before surgery and 4.8 mm at latest follow-up. Average duration of fixator use was 4.4 months. Four patients (36.4%) had complications. Articulated hip distraction was effective in eliminating pain, improving function, and preventing progressive degenerative changes in young patients' hips. It should be considered a salvage procedure for arthritic hips and an alternative to arthrodesis in this difficult-to-treat group of patients.     

Ultrasound for hip assessment in the newborn

The hips of 1000 newborn babies were examined clinically and by ultrasonography. The ultrasound assessment was based on measurements of the coverage of the femoral head by the bony acetabular roof, and this parameter was called the Bony Rim Percentage (BRP). The mean BRP was 55.3% in girls and 57.2% in boys, a significant difference. Clinical instability occurred in 0.7% of the newborn babies, and all of the unstable hips had a BRP below the lower limit of normal. All infants with normal clinical findings and suspected abnormal hips based on ultrasound were followed up; in all but two the hips became normal spontaneously. We conclude that ultrasonography, using the measurements of femoral head coverage, is appropriate for screening the newborn, is reliable in differentiating between a true and a false positive Ortolani sign, and that hip dysplasia which is not clinically demonstrable at birth can be detected by ultrasound. Ultrasound should replace radiography as the routine method of following up high-risk infants and those with suspicious signs.     

Reducing unnecessary crossmatching for hip fracture patients by accounting for preoperative hemoglobin concentration

BACKGROUNDMaximum surgical blood order schedules were designed to eliminate unnecessary preoperative crossmatching prior to surgery in order to conserve blood bank resources. Most protocols recommend type and cross of 2 red blood cell (RBC) units for patients undergoing surgery for treatment of hip fracture. Preoperative hemoglobin has been identified as the strongest predictor of inpatient transfusion, but current maximum surgical blood order schedules do not consider preoperative hemoglobin values to determine the number of RBC units to prepare prior to surgery. AIMTo determine the preoperative hemoglobin level resulting in the optimal 2:1 crossmatch-to-transfusion (C:T) ratio in hip fracture surgery patients.METHODSIn 2015 a patient blood management (PBM) program was implemented at our institution mandating a single unit-per-occurrence transfusion policy and a restrictive transfusion threshold of < 7 g/dL hemoglobin in asymptomatic patients and < 8 g/dL in those with refractory symptomatic anemia or history of coronary artery disease. We identified all hip fracture patients between 2013 and 2017 and compared the preoperative hemoglobin which would predict a 2:1 C:T ratio in the pre PBM and post PBM cohorts. Prediction profiling and sensitivity analysis were performed with statistical significance set at P < 0.05. RESULTSFour hundred and ninety-eight patients who underwent hip fracture surgery between 2013 and 2017 were identified, 291 in the post PBM cohort. Transfusion requirements in the post PBM cohort were lower (51% vs 33%, P < 0.0001) than in the pre PBM cohort. The mean RBC units transfused per patient was 1.15 in the pre PBM cohort, compared to 0.66 in the post PBM cohort (P < 0.001). The 2:1 C:T ratio (inpatient transfusion probability of 50%) was predicted by a preoperative hemoglobin of 12.3 g/dL [area under the curve (AUC) 0.78 (95% confidence interval (CI), 0.72-0.83), Sensitivity 0.66] in the pre PBM cohort and 10.7 g/dL [AUC 0.78 (95%CI, 0.73-0.83), Sensitivity 0.88] in the post PBM cohort. A 50% probability of requiring > 1 RBC unit was predicted by 11.2g/dL [AUC 0.80 (95%CI, 0.74-0.85), Sensitivity 0.87] in the pre PBM cohort and 8.7g/dL [AUC 0.78 (95%CI, 0.73-0.83), Sensitivity 0.84] in the post-PBM cohort.CONCLUSIONThe hip fracture maximum surgical blood order schedule should consider preoperative hemoglobin in determining the number of units to type and cross prior to surgery.     

Ultrasound screening for hip dysplasia in neonates

In a pilot study, hip development in 615 newborn children was assessed sonographically. Distinct dysplasia was found in 2.3%, and an intermediate "physiologically immature" hip development was noted in 13%. The number of controls and expenses would greatly increase if all physiologically immature hips were followed until they reached maturity. To reduce the number of unnecessary control and to facilitate assessment, we propose the use of "cut-off values" in a screening program for newborns.     

Ultrasound examination of the irritable hip

We made a prospective study of 111 children with acute hip pain to assess whether ultrasound can replace traditional radiography. An effusion was diagnosed in 71% by ultrasound but in only 15% by radiography. This effusion persisted for a mean of nine days; symptoms lasted for five days. Two patients found to have Perthes' disease had longer-lasting effusion and symptoms. Patients without an effusion had no obvious cause for their pain, so the pressure of an effusion from a transient synovitis does not account for all patients with irritable hips. Patients with an effusion persisting for over 24 days (the mean + 2 s.d. of our series) had more symptoms, a significantly larger effusion and greater limitation of movement. They may be more at risk for avascular necrosis. We found that radiographic examination influenced the immediate management of only two patients, those with Perthes' disease. We therefore propose a protocol of management for irritable hip, using ultrasonography at the first presentation of certain categories of patients. This would reduce the number of early radiographs by 75%.     

Radiographic anatomic structure of the arthritic acetabulum and its influence on total hip arthroplasty

Acetabular bone structure is not the same in all patients and can be defined by the radiolucent triangle superior to the acetabulum. Of 132 hips, 81 had an isosceles triangular shape, which was named type A acetabulum. Forty-six hips had an extension of the triangle into the teardrop, which created a thickened medial wall and was named type B. Five hips had a right-angle triangle, which was found only with congenital disease of the hip and was named type C. The density of the superior acetabular bone in the triangle could be normally radiolucent (stage I), have vertical and transverse trabeculae throughout the triangle (stage II), or have the triangle filled with bone and cysts (stage III). The relationship between progressive radiolucent lines and acetabular type showed that type A3 (thin medial wall with dense triangle bone) had the highest incidence of progressive radiolucent lines (P < .05).     

Geometrical values of the normal and arthritic hip and knee detected with the EOS imaging system

Purpose

EOS 2D/3D is an integrated, low-dose orthopedic digital radioimaging solution, which, due to its groundbreaking properties, has recently shown an increasing application in scoliosis surgery. Its integrated sterEOS 3D software allows creation of patient-specific three-dimensional (3D) lower limb models, and can produce geometrical parameters in 3D. Currently there are a limited number of reports on EOS for lower limb applications.

Methods

Three-dimensional reconstructions of 256 hip and knee joints of 128 healthy subjects, as well as 53 hips and 46 knees of 69 patients with hip or knee arthritis, were evaluated based on orthogonal EOS two-dimensional (2D) images. Measurements for hips included femur and tibia length, total length of the extremity, femoral antetorsion and offset, femoral neck length, neck-shaft and hip-knee-shaft (HKS) angles. Lower limb alignment in both frontal and sagittal planes were determined in normal and arthritic knees. Values were compared with those obtained by standard methods published by others.

Results

Normal hip and knee geometrical parameters were found in our healthy subjects. In osteoarthritic cases, values for neck-shaft angle, femoral antetorsion, femur length and total length of the extremity were shown to decrease non-significantly. Evaluation of lower limb alignment in healthy and arthritic knees showed normal values in healthy subjects apart from three cases with an average six degrees varus. Arthritic knees were most frequently found to have a varus angulation, with the exception of 11 cases with normal or valgus alignment.

Conclusion

EOS 2D/3D with its sterEOS 3D reconstruction is useful for a comprehensive 3D examination of the lower limb. In the near future it may be suitable for daily routine diagnostics of orthopedic lower limb deformities as a primary examination method.     

广东地区11132例新生儿髋关节超声测量

目的探讨用超声检查方法测量广东地区新生儿髋关节发育的情况。方法对11132例在广东出生的新生儿，采用超声检查方法进行髋关节测量，以超声骨缘覆盖率法（BRP）和动态检查结合作为会标准诊断髋关节发育不良（DDH）。结果广东地区新生儿髋脱位发病率为11．8‰，髋关节不稳定发病率为12．1％。正常新生儿髋关节超声测量值：α、β角，髋臼指数，骨缘覆盖率，股骨头覆盖率，髋臼直径，股骨头直径均值依次为59．56°，39．48°，30．50°，57．40％，56．96％，15．71mm，15．74mm。结论1．明确了广东地区新生儿髋关节发育指标及DDH的发病率；2．明确了南、北方人群新生儿DDH的发病率的差异无统计学意义，而髋臼发育各指标间的差异有统计学意义。     

External hip protectors are effective for the elderly with higher-than-average risk factors for hip fractures

Summary  In our cluster randomised controlled trial for efficacy of hip protector with 672 ambulatory elderly women, a hip protector was more effective for prevention of hip fractures in residents with fall history (n = 202; hazard ratio (HR), 0.375; 95%CI, 0.14–0.98; p = 0.05) and body-mass index (BMI) ≤ 19.0 (n = 206; HR, 0.37; 95%CI, 0.14–0.95; p = 0.04) by a Cox proportional hazards regression model. Introduction  Hip fractures result from both osteoporosis and falling. A potentially cost-effective method of preventing hip fractures involves the use of hip protectors but recent studies have revealed the uncertain effectiveness of hip protectors even in institutional settings. Methods  This study was a cluster randomised controlled trial with nursing homes. We randomly assigned 76 homes with 672 ambulatory but frail elderly women. Several risk factors were assessed at baseline and incorporated into a Cox proportional hazards regression model. UMIN Clinical Trials Registry number is UMIN000000467. Research period was between January 2004 and March 2006. Results  In the intervention group, 19 hip fractures occurred (54.0/1,000 person-years), whereas 39 hip fractures occurred in the control group (78.8/1,000 person-years). Hazard ratio of hip fracture in the intervention group was 0.56 (95%CI, 0.31–1.03; p = 0.06) after adjusting for risk factors. In subgroup analysis, hip protectors were more effective for prevention of hip fractures in residents with fall history (n = 202; HR, 0.375; 95%CI, 0.14–0.98; p = 0.05) and BMI ≤ 19.0 (n = 206; HR, 0.37; 95%CI, 0.14–0.95; p = 0.04). Overall compliance with use of hip protectors was 79.7%. Conclusion  Risk of hip fracture can be reduced by hip protectors among elderly women with fall history and low BMI.