Protrusio acetabuli in Marfan syndrome: age-related prevalence and associated hip function

The Musculoskeletal Manifestations of Marfan Syndrome: Diagnosis, Impact, and Management

Purpose of Review

Marfan syndrome (MFS) is an autosomal dominant heritable disorder of fibrillin-1 (FBN1) with predominantly ocular, cardiovascular, and musculoskeletal manifestations that has a population prevalence of approximately 1 in 5–10,000 (Chiu et al. Mayo Clin Proc. 89(1):34–42, 146, Dietz 3, Loeys et al. J Med Genet. 47(7):476–85, 4).

Recent Findings

The vascular complications of MFS still pose the greatest threat, but effective management options, such as regular cardiac monitoring and elective surgical intervention, have reduced the risk of life-threatening cardiovascular events, such as aortic dissection. Although cardiovascular morbidity and mortality remains high, these improvements in cardiovascular management have extended the life expectancy of those with MFS by perhaps 30–50 years from an estimated mean of 32 years in 1972 (Dietz 3, Gott et al. Eur J Cardio-thoracic Surg. 10(3):149–58, 147, Murdoch et al. N Engl J Med. 286(15):804–8, 148). The musculoskeletal manifestations of MFS, which to date have received less attention, can also have a significant impact on the quality of life and are likely to become more important as the age of the Marfan syndrome population increases (Hasan et al. Int J Clin Pract. 61(8):1308–1320, 127). In addition, musculoskeletal manifestations are often critically important in the diagnosis of MFS.

Summary

Here, we review the main clinically relevant and diagnostically useful musculoskeletal features of MFS, which together contribute to the “systemic features score” (referred to hereafter as systemic score), part of the revised Ghent nosology for MFS. We discuss current treatment strategies and highlight the need for a multidisciplinary approach to diagnosis and management. Finally, we review new pharmacological approaches that may be disease modifying and could help to improve the outcome for individuals with this syndrome.

Outcomes of Total Hip Arthroplasty in Patients With Acetabular Protrusio

Background:

Acetabular protrusio (AP) is associated with distorted anatomic landmarks and insufficient bone stock that increases complexity of total hip arthroplasty (THA). This study used a large national database to compare outcomes after THA in patients with and without AP.

Methods:

The Nationwide Readmissions Database was used to identify patients with and without AP who underwent THA from 2010 to 2014. Primary outcomes analyzed included complications during index hospitalization and within 90 days of THA.

Results:

Propensity score matching generated 4,395 patients without AP and 4,603 patients with AP. Patients with AP were older (68.1 versus 65.2 years, P < 0.0001), more predominantly women (82.1% versus 55.9%), and had more medical comorbidities as measured by the Elixhauser Comorbidity Index (2.29 versus 1.89, P < 0.0001). Patients with AP had an increased risk of requiring bone graft (odds ratio [OR] = 47.97, 95% confidence interval [CI]: 14.27 to 161.22), receiving a blood transfusion (OR = 1.90, 95% CI: 1.57 to 2.29), and suffering a periprosthetic fracture (OR = 2.56, 95% CI: 1.10 to 5.97) within 90 days of THA. Length and cost of index hospitalization were greater for patients with AP (5.0 versus 4.3 days, P = 0.002; $19,211.88 versus $27,736.30, P < 0.0001).

Conclusion:

Given the current emphasis on hospital cost optimization, it is important to ensure that patients with AP are managed appropriately. Attention should be placed on comprehensive preoperative planning and postoperative monitoring in this population.

Analysis of Protrusio Acetabuli Using a CT-based Diagnostic Method in Korean Patients with Marfan Syndrome: Prevalence and Association with Other Manifestations

A new CT-based diagnostic method of protrusio acetabuli (PA) was introduced. However, prevalence of PA by this method and correlation between PA and other manifestations of Marfan syndrome (MFS) is unknown in Korean MFS patients. This study aimed to investigate the prevalence of PA diagnosed by a CT-based method in Korean patients with MFS, the association of PA with other manifestations of MFS, and the contribution of PA to MFS diagnosis. We retrospectively reviewed the records of 146 MFS patients with the presence of a causative FBN1 mutation and 146 age- and sex-matched controls from a single tertiary care center. All MFS patients underwent a complete assessment of criteria based on the revised Ghent nosology. PA was assessed quantitatively using a CT-based circle-wall distance (CWD) method. PA was diagnosed in 77.4% of patients in the MFS group and in 11.0% of the control group. CWD was significantly different between the two groups (1.50 mm vs. -0.64 mm, P<0.001). The presence of PA did not correlate with the presence of ectopia lentis, aortic root diameter, or history of aortic dissection. The presence of PA did not have a significant impact on the final diagnosis of MFS. Even though the presence of PA does not related to the cardinal clinical features of MFS or influence MFS diagnosis, its presence may be helpful for the suspicion of MFS when aortic dissection or aneurysm is found on CT angiography of the aorta because of the high frequency of PA in MFS patients.

Bilateral hip arthritis in a case of renal osteodystrophy

Chronic renal disease is often associated with secondary hyperparathyroidism (HPP) and rarely with tertiary HPP. Hip arthritis with protrusio acetabuli, secondary to tertiary HPP, is a rare case scenario and has not been described well in the literature. We present a rare case of bilateral hip arthritis with protrusio acetabuli secondary to renal osteodystrophy due to tertiary HPP. The diagnosis and aetiology of hip arthritis and its treatment have been discussed along with a detailed review of literature of skeletal lesions due to HPP.

Protrusio acetabuli and total hip arthroplasty in patients with Marfan syndrome

Our goals were (1) to quantify protrusio acetabuli in patients with Marfan syndrome who underwent total hip arthroplasty and (2) to identify clinical results and complications associated with total hip arthroplasty in those patients. We reviewed the preoperative radiographs of the 29 patients (38 hips) in our study and analyzed the related patient operative reports, postoperative records, and self-administered questionnaires (mean follow-up, 116 ± 102 months). The mean preoperative center-edge angle of Wiberg was 50.9° ± 14°. Loosening (3) and radiolucent lines (4) occurred in femoral but not acetabular components. The hips had 15 complications, including 8 reoperations. High questionnaire scores (82 ± 13 points) indicated good hip function regardless of preoperative protrusio severity.

CT of the hips in the investigation of protrusio acetabuli in Marfan syndrome. A case control study

OBJECTIVES

To establish the prevalence of protrusio acetabuli (PA) in adults fulfilling the Ghent criteria for Marfan syndrome (MFS), and in a normal adult population.

METHODS

105 adults with probable MFS and 107 controls were included. CT of the hips was obtained. A qualitative assessment of PA was performed. A new method for estimating the degree of PA was introduced with measurement of the parameter CWD (circle-wall distance). Results were compared to an alternative method based on MRI [1].

RESULTS

87 of the study group fulfilled the Ghent criteria of MFS (Ghent positives), and 18 did not (Ghent negatives). PA was diagnosed qualitatively in 74.7% of Ghent positive persons, in 27.8% of Ghent negative persons, and in 3.7% of the controls. CWD was significantly different between the three groups (p < 0.001). A slight but significant gender difference was found in Ghent positive persons only. The alternative method did not differentiate between the groups with respect to PA, but showed a significant difference between genders.

CONCLUSIONS

PA was found significantly more often in MFS persons than in controls. Our method was found to be robust and highly reproducible, giving a direct measurement of pelvic protrusion irrespective of pelvic shape.

Cams and pincer impingement are distinct, not mixed: the acetabular pathomorphology of femoroacetabular impingement

BACKGROUND

Many impinging hips are said to have a mix of features of femoral cam and an overcovered acetabulum causing pincer impingement. Correction of such a mixed picture by reduction of the cam lesion and the acetabular rim is the suggested treatment.

QUESTIONS/PURPOSES

We therefore asked two questions: (1) Is the acetabulum in cam impingement easily distinguishable from the pincer acetabulum, or is there a group with features of both types of impingement? (2) Is version or depth of socket better able to distinguish cam from pincer impingement?

METHODS

We analyzed the morphologic features of the acetabulum and rim profile of 20 normal, healthy hips, 20 with cams and 20 with pincers on CT. Pelvises were digitized, orientated to the best-fit acetabular plane, and a rim profile was plotted.

RESULTS

Cam hips were shallower than normal hips, which in turn were shallower than pincer hips (84 degrees +/- 5 degrees versus 87 degrees +/- 4 degrees versus 96 degrees +/- 5 degrees, respectively). The rim planes of cam, normal, and pincer hips had similar version (23 degrees, 24 degrees, 25 degrees), but females were 4 degrees more anteverted than males.

CONCLUSIONS

We concluded cam and pincer hips are distinct pathoanatomic entities. Cam hips are slightly shallower than normal, whereas pincers are deeper.

CLINICAL RELEVANCE

Before performing surgery for cam-type femoroacetabular impingement, surgeons should consider measuring the acetabular depth. The cam acetabulum is shallower than normal and may be rendered pathologically shallow by acetabular rim resection leading to early joint failure.

Recent molecular biological progress in Marfan syndrome and Marfan-associated disorders

Marfan syndrome (MFS) is a connective tissue disorder with autosomal dominant inheritance. Advances in medicine and surgery have increased the average lifespan of classically affected patients. Serious visual and/or musculoskeletal impairment often has detrimental effects on day-to-day activities and quality of life. MFS patients suffer from many problems at younger ages and with higher frequencies than the general population because of the degenerative nature of the genetic condition. In classical MFS, changes are caused by mutations in the fibrillin-1 gene (FBN1). Mutations in the fibrillin-2 gene were discovered in individuals with a phenotypically related disorder, congenital contractural arachnodactyly. Some of the clinical manifestations of MFS cannot be explained by mechanical properties alone. Recently, mutations in the genes required for transforming growth factor-beta signaling (TGFBR1 and TGFBR2) have been found in several disorders with varying degrees of overlap with classical MFS, including Loeys-Dietz syndrome and familial thoracic aortic aneurysms and dissections. MFS is a disorder that is variable in its phenotypic expression. Specific information about mutations in the large FBN1 gene will give rise to more information about the phenotype-genotype correlations. Possible molecular mechanisms for the pathogenesis of MFS will be discussed which may assist healthcare professionals to control environmental factors that provoke individual complications in MFS.

Marfan syndrome

Marfan syndrome is a variable autosomal dominant disorder; most cases result from mutations of fibrillin-1. Diagnosis is guided by the Ghent nosology. The condition may manifest in the cardiovascular and ocular systems. Musculoskeletal manifestations include scoliosis, dural ectasia, protrusio acetabuli, and ligamentous laxity. Compared with patients with idiopathic scoliosis, patients with Marfan syndrome tend to have scoliosis that progresses at a faster rate and is more resistant to bracing; undergo scoliosis surgery complicated by greater blood loss, pseudarthrosis, and additional curvature; and have more frequent occurrences of dural ectasia, which may cause headaches, leg pain, or perineal pain. Protrusio acetabuli may result in hip joint arthritis and may require valgus osteotomy or total hip arthroplasty.