Frog-leg View Research Articles

Computer-Assisted Technique to Delineate Osteolytic Lesions Around the Femoral Component in Total Hip Arthroplasty

There are currently no ideal quantitative measures assessing osteolysis after total joint arthroplasty. This study reports a new approach for quantification of osteolytic lesions on radiographs of total hip arthroplasty with the hypothesis that computer-assisted lesion quantification improves analysis precision over currently used qualitative visual assessment and thus improves progression monitoring. Duplicate exposure sets of anterior-posterior and frog-leg view radiographs of 15 volunteer total hip arthroplasty patients with radiographically evident periprosthetic lucencies were used. Two independent readers delineated the lesions using on-screen digital marker tools. Based on duplicate readings of the first exposure set only, intraoperator precision had a coefficient of variation (CV) from 1.5% to 3.4%, whereas interoperator precision CV ranged from 3.2% to 4.6%. The reproducibility of the x-ray technique as assessed by single readings of both sets of x-rays was CV 3.2% to 4.8%. The new technique compares favorably to precision of qualitative visual assessment and permits more accurate detection and quantitation of osteolytic lesions.

Chronic Renal Failure Presenting Primarily With Renal Osteodystrophy: A Case Report

Chronic Renal Failure Presenting Primarily With Renal Osteodystrophy: A Case Report

Southwick's head-shaft angles: normal standards and abnormal values observed in obesity and in patients with epiphysiolysis.

Southwick's angles measured in the anteroposterior and Lauenstein frog-leg views have been used for planning surgical treatment of deformities caused by slipped capital femoral epiphysis (SCFE). Clinically established epiphysiolysis is associated with a decrease in anteroposterior angles and an increase in Lauenstein angles. Obesity is one of the factors involved in the development of SCFE, but its influence in Southwick's angles has not been previously described. Additionally, few reports describe normal values adjusted for sex and bone age. In this study, we determined Southwick's angles in normal control participants (n=70), in patients with obesity (n=31) and in patients with epiphysiolysis (n=33). The intra-observer variations were 1.7 and 23.3% for the anteroposterior and Lauenstein angles, respectively. No significant differences were detected in the control group when these individuals were compared according to sex or chronological age. Obese patients showed a significant increase in the anterposterior angle when compared with control individuals. The hip with epiphysiolysis presented a significant reduction in the anteroposterior angle and an increase in the Lauenstein angle, when the same was compared with the contralateral hip or with the control values. In patients with unilateral SCFE the Lauenstein angle of the normal hip was detected as increased, which was possibly related to the obesity associated with decreased insulin resistance presented by these patients. We conclude that the detection of risk for developing SCFE should include an expanded clinical and radiological profile characterized by pubertal males who present obesity associated with insulin resistance and an increase in Southwick's anteroposterior angle.

Reliable X-ray diagnosis of slipped capital femoral epiphysis by combining the conventional and a new simplified geometrical method.

The diagnosis of subtle slipped capital femoral epiphysis (SCFE), for example in the contralateral asymptomatic hip, may require use of an exactly defined and reproducible lateral view where the slipping angle can be measured. To test a simplified geometrical method and compare it to the conventional method (AP and frogleg views). The two methods were compared in 95 normal children 9-14 years old and 100 children 9-20 years old with SCFE. The slipping angle (SA) measurements had very high reproducibility, and the new method was diagnostically superior to the conventional method ( P<0.05). An exactly defined and reproducible lateral view is recommended for the X-ray diagnosis of SCFE. Nontraumatic SCFE appears to be bilateral in all cases.

Femoral stress abnormalities: improved scintigraphic detection with frog-leg view.

To identify a better scintigraphic imaging technique for detecting proximal femoral stress abnormalities, 51 consecutive patients with hip pain and the clinical suspicion of stress injury underwent three-phase bone scanning with technetium-99m methylene diphosphonate. Delayed scanning included anterior and frog-leg views of the hips. Fifteen patients had focal stress abnormalities of the femoral neck or lesser trochanter; all were detected with the frog-leg view, but only seven were detected with the standard anterior view. Stress abnormalities involving the lesser trochanter were depicted especially well on the frog-leg view.