Femoral Head Extrusion Research Articles

Natural History of Early Onset and Late-Onset Legg-Calve-Perthes Disease

Legg-Calve-Perthes disease develops after interruption of the blood supply to the capital femoral epiphysis. This results in various changes in the femoral epiphysis and metaphysis, the capital femoral epiphysis, growth plate, and the acetabulum. The necrotic bone of the epiphysis is gradually replaced by new bone, and over 2 to 4 years complete healing of the epiphysis occurs. The evolution of this process can be clearly seen on radiographs and the disease can be divided into distinct stages. In the early stages of the disease, the epiphysis may extrude outside the confines of the acetabulum and this predisposes to femoral head deformation. The propensity for femoral head extrusion is greater in the older child, and consequently the likelihood of femoral deformation is higher in children who are older.

Radiographic Predictors of Hip Pain in Femoroacetabular Impingement

The primary diagnosis of femoroacetabular impingement is based on clinical symptoms, physical exam findings, and radiographic abnormalities. The study objective was to determine the radiographic findings that correlate with and are predictive of hip pain in femoroacetabular impingement (FAI). One hundred prospective patients with unilateral FAI symptoms based on clinical and radiographic findings were included in this study. All patients filled out a WOMAC pain questionnaire. Two independent-blinded surgeons assessed antero-posterior and lateral radiographs for 33 radiographic parameters of FAI. Correlations between pain scores and radiographic findings were calculated. A matched radiographic analysis was performed comparing symptomatic versus asymptomatic hips. Radiograph findings were also compared between males and females. Weak positive correlations were identified between increasing pain scores with radiographic findings of posterior wall dysplasia, presence of a shallow socket, and a more lateral acetabular fossa relative to the Ilioischial line. A symptomatic hip had a lower neck shaft angle, greater distance from Ilioischial line to acetabular fossa and larger distance from cross-over sign to superolateral point of the acetabulum when compared to the asymptomatic hip in the same patient. Symptomatic hips in males had more joint space narrowing, femoral osteophytes, higher alpha angles and larger, more incongruent femoral heads compared to females. Females had more medial acetabular fossa relative to the Ilioischial line and smaller femoral head extrusion index. Similar to other musculoskeletal conditions, radiographic findings of FAI are poor predictors of hip pain.

Periacetabular osteotomy for the treatment of developmental dysplasia of the hip in adults

Objective To study the indications and mid-term outcomes of periacetabular osteotomy on adult patients of developmental dysplasia of the hip (DDH). Methods Twenty-five adult patients with DDH underwent periacetabular osteotomies through modified Smith-Peterson approach. There were 19 females and 6 males with an average age of 25.5 years (range, 18-45). Every patient had a single dysplasia hip, including 14 hips in the left, and the other 11 in the right. Three cases were operated formerly, 2 of them received Chari osteotomy and 1 received Salter osteotomy. Before operation 13 hips were T(o)nnis Grade 0 osteoarthritis, 9 hips were Grade Ⅰ , 3 hips were Grade Ⅱ. The Shenton line of 18 hips was broken. The lateral center-edge angle was 4.57°±7.39°, the anterior center-edge angle was 0.95°±6.02°, the horizontal tilt angle was 32.50°±5.96°, the femoral head extrusion index was 38.11％±5.70％, the Harris hip score was 75.32±7.51 points. Changes of the indexes mentioned above were observed during the period of follow-up.Results All patients were followed up for average 4.5 years (range, 2.0-7.5). Compared with the preoperative radiographic severity at the latest follow-up, 3 hips of T(o)nnis Grade Ⅰ improved to Grade 0, 2 hips of Grade Ⅱ improved to Grade Ⅰ, 1 hip of Grade Ⅰ changed into Grade Ⅱ. The incident of the break of Shenton line decreased to 10 hips. The lateral center-edge angle improved to 29.07°±5.81° the anterior centeredge angle improved to 29.52°±4.51°, the horizontal tilt angle decreased to 19.17°±4.95°, the femoral head extrusion index decreased to 24.20％±4.83％, the Harris hip score increased to 84.88±4.88 points. The major complication included 16 cases of lateral femoral cutaneous nerve palsy (7 cases of them didn't recover forever) and 1 case of ectopic ossification of Brooker Ⅰ . Conclusion Periacetabular osteotomy through a modified Smith-Peterson approach were performed to the dysplasia hip of adults, it can increase congruence,improve hip function; it can also prevent subchondral sclerosis and cysts forming, preserve joint space and delay the occurrence of osteoarthritis. Key words: Hip dislocation, congenital; Osteotomy; Acetabulum; Osteoarthritis, hip

Complications Associated with the Bernese Periacetabular Osteotomy for Hip Dysplasia in Adolescents

The Bernese (Ganz) periacetabular osteotomy is an effective surgical procedure to reorient the acetabulum, allowing restoration of anatomic femoral head coverage and medial translation of the hip in adults with hip dysplasia. However, it is a challenging surgical procedure, and we know of no study that has specifically analyzed the complications and associated factors seen with this procedure in adolescent patients. A retrospective clinical and radiographic review of a consecutive series of adolescent patients who underwent a Bernese periacetabular osteotomy for hip dysplasia was conducted. Eighty-three osteotomies were performed in seventy-six patients with an average age (and standard deviation) of 15.6 +/- 2.4 years. Significant improvement from the preoperative to the two-year follow-up evaluation was seen radiographically with regard to the lateral center-edge angle (-0.14 degrees to 35.5 degrees), the ventral center-edge angle (-5.13 degrees to 31.3 degrees), and the femoral head extrusion index (38.4% to 7.7%) (p < 0.0001 for all). There were three major complications, including excessive arterial bleeding requiring embolization in a patient with a prior acetabuloplasty, osteonecrosis of the acetabular fragment in a patient with severe dysplasia and subluxation of the hip, and osteonecrosis of the femoral head following combined periacetabular and femoral osteotomies in a patient with Charcot-Marie-Tooth disease. Eighteen hips (22%) had minor complications, including nonunion of the superior pubic ramus osteotomy (five hips), a superficial stitch abscess (four), and transient lateral femoral cutaneous nerve palsy (four). Nine hips (11%) underwent removal of symptomatic screws, and two required a second operation to reposition the acetabular fragment. An underlying diagnosis other than developmental dysplasia increased the prevalence of minor complications (p = 0.0017), while a major complication was more likely with longer surgery time, greater blood loss, and proximal femoral osteotomy. The Bernese periacetabular osteotomy is a joint-preserving procedure that very effectively corrects acetabular dysplasia in adolescent patients, providing improved radiographic results and a low rate of complications. Although the rate of minor complications is increased when there is an underlying diagnosis other than developmental dysplasia, no other predictors were identified. However, a major complication is more likely with a longer duration of surgery and with a concomitant femoral varus osteotomy.

In Brief: Crowe’s Classification: Arthroplasty in Developmental Dysplasia of the Hip

In Brief: Crowe’s Classification: Arthroplasty in Developmental Dysplasia of the Hip

Varus producing osteotomy for patients with lateral pillar type B and C Legg-Calve-Perthes disease followed to skeletal maturity. Castaneda et al. JCOR (2008), 2:373–379

Dear Editors, I read the paper by Castaneda et al. about LCP with great interest. In the paper’s introduction section, the authors state that “many of the concepts regarding the disease have not evolved in almost a century.” This is quite unfortunate indeed, and I fully agree with them. The study is well conducted, and the paper is well written. However, I would be less affirmative in stating that femoral varus osteotomy (FVO) achieves similar results to non-operative treatment in Herring B and C. Their findings may not necessarily support this conclusion. The fact that both treatments lead to almost similar results, even slightly worse in the surgically treated group, do not mean that one should observe severely involved Perthes hips and never take them to surgery, be it pelvic or femoral. Important clinical and radiological information is necessary to support their statement and is missing from their paper. Although classification according to Caterall and/or Herring certainly has a prognostic implication, other factors play a major role in determining outcome and are certainly used for decision making by a vast majority of pediatric orthopedic surgeons around the globe. The Iowa hip score and the Stulberg classification were used in this study to determine the outcome at final follow-up, but no information is given to the reader concerning preoperative clinical and radiological differences (other than the Herring classification) between both groups, mainly those related to hip motion, hinge abduction, and the severity of femoral head extrusion or subluxation. Severity of involvement should not only be decided based on the height of the lateral pillar, as we all know. Two hips classified as Herring C may behave completely differently and lead to different outcomes following operative or non-operative treatments. In fact, one could assume that cases where FVO was performed were clinically and radiographically initially more severe with obvious and progressive lack of containment compared to cases where non-operative management was decided upon and undertaken. From another angle, why did the physicians who chose to treat Herring C hips nonsurgically decide to do so, and why did those who operated on similar hips (based only on the classification) decide to do so? In my perspective, viewed from this angle, a similar outcome in both groups could rather be seen as being in favor of performing FVO in severely affected and subluxed hips, as it may improve the hip situation to a point where it becomes similar to those hips that do not need surgery. This is an issue that I was just discussing with some colleagues who had the same impression after reading the manuscript, and I wanted to share it with you and the authors. I am sure that they have conducted and worked out this study so well that the information I am asking for can be easily made available, maybe as a basic criteria for further studies and publications on such a mysterious and controversial disease. Once again, I would like to congratulate the authors for this long-term, well-conducted and well-written study, and I thank them in advance for their answer. Sincerely, Ismat Ghanem

A Systematic Approach to the Plain Radiographic Evaluation of the Young Adult Hip

Orthopaedic evaluation of hip pain in the young adult population has undergone a rapid evolution over the past decade1,2. This is in large part due to enhanced awareness of structural hip disorders, including developmental dysplasia of the hip and femoroacetabular impingement1-5. Surgical treatment for these disorders continues to be refined6-9, and our ability to identify patients along the spectrum of disease continues to improve10-15. Yet, despite our advances, obtaining an accurate diagnosis can remain challenging, especially in the setting of mild structural abnormalities. Therefore, radiographic examination is a critical component of the diagnostic evaluation and treatment decision-making process. It is essential that physicians have common and reliable radiographic views as well as parameters for plain radiographic assessment that can serve as a foundation for accurate diagnosis, disease classification, and surgical decision-making. Many different radiographic measurements have been described as indicators of structural disease. In particular, measurements such as the lateral center-edge angle of Wiberg16, the anterior center-edge angle of Lequesne17, the ac-etabular index of depth to width described by Heyman and Herndon18, the femoral head extrusion index19, and the Tonnis angle20 have been used as markers for acetabular dysplasia. Similarly, measurements of acetabular version21, the head-neck offset (initially described by Eijer)3,22, and the alpha angle19 have been used in the diagnosis of femoroacetabular impingement. Nevertheless, there is limited literature that provides comprehensive information regarding the details of radiographic evaluation in the young patient with hip symptoms. This paper summarizes the recommendations of the ANCHOR (Academic Network for Conservational Hip Outcomes Research) study group regarding the most important aspects of radiographic technique and image interpretation to evaluate the symptomatic, skeletally mature hip.

Comprehensive Morphologic Evaluation of the Hip in Patients with Symptomatic Labral Tear

A torn acetabular labrum is a well-documented source of hip pain, but the mechanism of injury is debated because the relationship between the bone morphology and labral tears is poorly understood. We compared hips with and without labral abnormalities to determine the relative incidence of morphologic abnormalities. The study group consisted of patients with a labral tear confirmed by arthroscopy or arthrotomy at the time of open débridement or periacetabular osteotomy. We compared the affected hip with the contralateral, unaffected hip to ascertain signs of hip dysplasia and impingement. We observed differences in the center edge angle, acetabular depth to width index, acetabular index of elevation, femoral head extrusion, lateral and superior subluxation, Sharp's angle, peak to edge distance, and acetabular retroversion. Similar differences occurred in the subgroup analyses. Symptomatic labral tears correlated with abnormal hip morphology as reflected by radiographic measurements of dysplasia and impingement. This relationship occurred in patients with hip dysplasia and patients without obvious femoral head uncovering. Our findings suggest abnormal hip morphology may be a risk factor for labral tears.

Hip dysplasia and osteoarthrosis

Introduction Hip dysplasia (HD) is assumed to be an etiological factor in the development of premature hip osteoarthrosis (OA). We established the prevalences of HD and OA in adults according to qualified radiographic discriminators, and investigated the relationship between HD and OA.Methods Wiberg′s CE angle (CE), Sharp′s angle, the femoral head extrusion index, the acetabular depth ratio (ADR), the radiographic OA discriminators of Croft, and of Kellgren and Lawrence, and also minimum joint space width (JSW) ≤ 2 mm were applied to the standing, standardized pelvic radiographs of 1 429 men (22-93 years), and 2 430 women (22-92 years).Results The 4 HD discriminators were interrelated. A negligible sex-related difference in acetabular morphology was found, male acetabulae being slightly more dysplastic than female acetabulae. However, differences between the sexes for right and left CE angles were within 1.0°, and within 1.4° for right and left Sharp′s angles. There were no cases of hip subluxation (breakage of Shenton′s line ≥ 5 mm). Average CE angle was 34° in men (SD 7.3°), and 35° in women (SD 7.6°). Applying a CE cut-off value of 20° for designation of definite hip dysplasia, we found a prevalence of hip dysplasia of 3.4%. Approximately 2% of cases were unilateral and 1.4% of cases were bilateral. We found significant relationships between radiographic OA discriminators and the CE angle, femoral head extrusion index and ADR. Odds ratios ranged from 1.0 to 6.2. Compared to subjects with OA in morphologically normal hips, a trend towards younger age in subjects with HD and OA was noted, but this was not strictly significant.Interpretation We found that HD is not uncommon in the general population. The assumption that HD is an etiological factor in the development of hip OA was confirmed.

How does a femoral varus osteotomy alter the natural evolution of Perthesʼ disease?

To study how a femoral osteotomy alters the natural evolution of Perthes' disease, records and radiographs of 640 patients with Perthes' disease were analyzed. The data of 314 patients who underwent femoral osteotomy were compared with those of non-operated patients. A new modification of classification of the stages of evolution of the disease was used to identify the timing of surgery and to monitor the progress of the disease following surgery. The duration of each stage of the disease, the extent of epiphyseal extrusion, the extent of widening of the femoral metaphysis and the dimensions of the acetabulum were noted on sequential radiographs. The changes in the femoral epiphysis and metaphysis and changes in the acetabulum were also noted. It was observed that a varus osteotomy clearly alters the natural evolution of Perthes' disease. Of patients who were operated in the stage of avascular necrosis, 34% bypassed the stage of fragmentation. The duration of the disease was shorter in these patients. The duration of the stage of fragmentation was reduced in operated children who passed through the stage of fragmentation. The extent of femoral head extrusion was minimized at the stage when it was most vulnerable for deformation. Metaphyseal widening and subsequent femoral head enlargement were also minimized in children who underwent a femoral osteotomy. The chances of retaining the sphericity of the femoral head were much higher in those children who had a femoral osteotomy. These beneficial effects of a varus osteotomy, were most evident when the operation was performed either in the stage of avascular necrosis or in the early stage of fragmentation.

Pelvic orientation and assessment of hip dysplasia in adults

The study was performed to qualify the source material of 4151 pelvic radiographs for the research into the relationship between unrecognised childhood hip disorders and the development of hip osteoarthrosis, and to investigate the effect of varying degrees of pelvic tilt and rotation on the measurements of radiographic indices of hip dysplasia. We investigated the effect of varying pelvic orientation on radiographic measurements of acetabular dysplasia using a cadaver model. Results from the cadaver study were used to validate the radiographic assessments of acetabular dysplasia in the longitudinal survey cohort of the Copenhagen City Heart Study (CCHS; Osteoarthrosis Sub-study). 1) Cadaver pelvises and proximal femurs from a male and a female donor were mounted anatomically in holding devices allowing independent inclination/reclination and rotation. An AP pelvic radiograph was recorded at each 3 degrees increment. The most widely used radiographic parameters of hip dysplasia were assessed. 2) Critical limits of acceptable rotation and inclination/reclination of pelvises were determined on 4151 standing, standardised pelvic radiographs of the CCHS cohort. Wiberg's CE angle, Sharp's angle, the x-coordinate of Goodman's Cartesian coordinate system, and the acetabular depth ratio were significantly affected by varying rotation and inclination/reclination of the cadaver pelvises. Femoral head extrusion index was not significantly affected within the applied rotation and inclination/reclination of the cadaver study. Application of the corresponding critical limits of Tönnis' foramen obturator index of 0.7-1.8 meant that 188 of 4151 (4.5%) of the CCHS-III pelvic radiographs had to be omitted from further studies. To ensure a neutral starting point and reproducible readings, especially in epidemiological and clinical studies, and when performing preoperative planning and follow-up of patients undergoing redirectional pelvic osteotomies, it is important that all aspects of the radiographic examination are controlled and reproducible. Furthermore, we found that studies of acetabular dysplasia based on supine urograms or colon radiographs without information about pelvic orientation, centering of the X-ray beam and tube to film distance, run a serious risk of erroneous measurements.

Indications for Intertrochanteric Osteotomy After Periacetabular Osteotomy for Adult Hip Dysplasia

Residual hip dysplasia in the adult is characterized by deficient anterior and lateral acetabular coverage with subsequent hip joint incongruity and instability. The frequency of periacetabular osteotomy for the treatment of residual hip dysplasia is increasing. In certain morphologic conditions preoperative abduction or intraoperative radiographs reveal that congruency after a periacetabular osteotomy is not optimum; at this point the surgeon may consider the addition of an intertrochanteric osteotomy. In a retrospective study, the radiographs of 25 patients who had a femoral osteotomy with or after periacetabular osteotomy were analyzed and the results were compared with a control group of 34 patients who had periacetabular osteotomy without a femoral osteotomy. The analyzed parameters included: the femoral head extrusion index and the acetabular index, before and after periacetabular osteotomy; the femoral neck shaft angle; the presence of femoral head deformity; the presence of osteoarthrosis; the presence of a secondary acetabulum; the influence of previous ipsilateral hip surgery; the effect of hip adduction or abduction on joint congruency; and the age of the patient. The variables that had a statistically significant association with the performance of an intertrochanteric osteotomy included a femoral head extrusion index and an acetabular index after periacetabular osteotomy outside the normal limits, a neck shaft angle outside the limits of the control group, a deformed femoral head, an osteoarthritic hip, a secondary acetabulum, and a joint space height and congruency dependent on position of the proximal femur. When using statistically significant variables, a discriminant analysis predicted the correct group (periacetabular osteotomy with femoral osteotomy, or periacetabular osteotomy without femoral osteotomy) for 89% of the cases.