Closed treatment of hip dislocation in Down syndrome

Effect of the Sharrard procedure on hip instability in children with Down syndrome: a retrospective study

PURPOSE

The aim of this study was to retrospectively analyze the effect of the Sharrard procedure on hip instability in children with Down syndrome (DS), as measured by the migration index.

METHODS

In total, 17 children (21 hips) were included from six hospitals in the Netherlands between 2003 and 2019. The primary outcome, hip instability, was assessed with the Reimers' migration index on preoperative and postoperative plain anteroposterior pelvic radiographs. The mean age at surgery was 8.1 years, the majority of children were male (64.7%) and the mean follow-up time was 7.3 years.

RESULTS

The mean preoperative migration index was 46% (sd 23.5) and the mean postoperative migration index was 37% (sd 28.4). The mean Delta migration index (the difference in pre-operative migration index and most recent post-operative migration index) showed an improvement of 9.3% (sd 22.7). An improvement in migration index was observed in 52%, no change in 29% and deterioration in 19% of hips. No (re)dislocations occurred in 91% of the hips. No major complications were observed during the follow-up period.

CONCLUSION

Early intervention is warranted in children with DS showing hip instability or hip migration, in order to succeed with less complex procedures. The Sharrard procedure should be considered in children with DS showing hip instability or hip migration, since it aims to rebalance the muscles of the hip joint, is less complex than bony procedures of the femur and acetabulum, surgery time is often shorter, there are fewer major complications and the rehabilitation period is shorter.

LEVEL OF EVIDENCE

IV - retrospective case series.

Hip Instability in Patients With Down Syndrome

The incidence of hip instability in children with Down syndrome is 1% to 7%. The natural history is often progressive, with the typical onset of hypermobility of the hip evolving to habitual dislocation, persistent subluxation, and fixed dislocation, and eventually leading to the loss of independent mobility. Treatment focuses on stabilizing the hip joint and depends on the patient's age and the severity of the disease. Typically, surgical intervention is recommended for the treatment of patients with habitual dislocation, subluxation, and complete dislocation of the hip. When indicated, surgical management must take into account associated anatomic abnormalities of the femur and acetabulum. Hip instability in Down syndrome may persist despite surgical intervention and remains a difficult condition to manage.

Preliminary results of an anteverting triple periacetabular osteotomy for the treatment of hip instability in Down syndrome

PURPOSE

To investigate the outcomes of an anteverting triple periacetabular osteotomy for the treatment of hip instability in skeletally immature patients with Down syndrome.

METHODS

We evaluated 16 patients (21 hips) with Down syndrome and hip instability who underwent an anteverting triple periacetabular osteotomy between 2007 and 2016. There were nine females and seven males with an average age of 7.4 years SD 2.0. We assessed the level of hip pain, gait ability and clinical stability at a minimum of one year after surgery. Radiographic evaluation included pre- and postoperative lateral centre-edge angle (LCEA), Tönnis acetabular angle and extrusion index.

RESULT

After an average follow-up of 4.1 years SD 2.6, 20 of 21 hips (95%) remained clinically stable. In all, 12 of 16 (75%) patients had a full gait without a major limp, but three patients (19%) had a persistent limp. Of the 21 procedures, one hip (5%) was considered a failure due to persistent instability. There was a mean increase of 18.3º SD 15.3º of the LCEA (p < 0.001); a mean decrease of 15.2º SD 11.6º (p < 0.001) for the Tönnis angle and the extrusion index had a mean decrease of 0.27 SD 0.20 (p < 0.001). The most common complications were minor and included nonunion of the pubis or ischium (24%) and stress fractures of the pubis and ischium (14%). Only one patient required unplanned surgery for the treatment of an infection; which was considered a major complication.

CONCLUSION

The anteverting triple periacetabular osteotomy provided global deformity correction and achieved hip stability in 95% of the hips after a mean follow-up of 4.1 years.

LEVEL OF EVIDENCE

Therapeutic level IV.

Acetabular Global Insufficiency in Patients with Down Syndrome and Hip-Related Symptoms: A Matched-Cohort Study

BACKGROUND

The etiology of hip instability in Down syndrome is not completely understood. We investigated the morphology of the acetabulum and femur in patients with Down syndrome and compared measurements of the hips with those of matched controls.

METHODS

Computed tomography (CT) images of the pelvis of 42 patients with Down syndrome and hip symptoms were compared with those of 42 age and sex-matched subjects without Down syndrome or history of hip disease who had undergone CT for abdominal pain. Each of the cohorts had 23 male and 19 female subjects. The mean age (and standard deviation) in each cohort was 11.3 ± 5.3 years. The lateral center-edge angle (LCEA), acetabular inclination angle (IA), acetabular depth-width ratio (ADR), acetabular version, and anterior and posterior acetabular sector angles (AASA and PASA) were compared. The neck-shaft angle and femoral version were measured in the patients with Down syndrome only. The hips of the patients with Down syndrome were further categorized as stable (n = 21) or unstable (n = 63) for secondary analysis.

RESULTS

The hips in the Down syndrome group had a smaller LCEA (mean, 10.8° ± 12.6° compared with 25.6° ± 4.6°; p < 0.0001), a larger IA (mean, 17.4° ± 10.3° compared with 10.9° ± 4.8°; p < 0.0001), a lower ADR (mean, 231.9 ± 56.2 compared with 306.8 ± 31.0; p < 0.0001), a more retroverted acetabulum (mean acetabular version as measured at the level of the centers of the femoral heads [AVC], 7.8° ± 5.1° compared with 14.0° ± 4.5°; p < 0.0001), a smaller AASA (mean, 55.0° ± 9.9° compared with 59.7° ± 7.8°; p = 0.005), and a smaller PASA (mean, 67.1° ± 10.4° compared with 85.2° ± 6.8°; p < 0.0001). Within the Down syndrome cohort, the unstable hips showed greater femoral anteversion (mean, 32.7° ± 14.6° compared with 23.6° ± 10.6°; p = 0.002) and worse global acetabular insufficiency compared with the stable hips. No differences between the unstable and stable hips were found with respect to acetabular version (mean AVC, 7.8° ± 5.5° compared with 7.6° ± 3.8°; p = 0.93) and the neck-shaft angle (mean, 133.7° ± 6.7° compared with 133.2° ± 6.4°; p = 0.81).

CONCLUSIONS

Patients with Down syndrome and hip-related symptoms had more retroverted and shallower acetabula with globally reduced coverage of the femoral head compared with age and sex-matched subjects. Hip instability among those with Down syndrome was associated with worse global acetabular insufficiency and increased femoral anteversion, but not with more severe acetabular retroversion. No difference in the mean femoral neck-shaft angle was observed between the stable and unstable hips in the Down syndrome cohort.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Hip Instability in Down Syndrome: A Focus on Acetabular Retroversion

BACKGROUND

The aim of this study is to compare acetabular anteversion between children with Down syndrome with or without hip instability. The second aim is to report the surgical experience at our institution in treating unstable hips for this population.

METHODS

All children with Down syndrome who were seen at our institution between 2004 and 2014 were reviewed, and those who had pelvic axial computed tomographic or magnetic resonance imaging scans were identified. Acetabular anteversion was compared between 2 groups: those with hip instability as a single hip pathology and those without hip instability. For patients who had surgery for their unstable hips, demographic, clinical, and surgical data were recorded. Preoperative and last visit radiographs were reviewed. Extrusion index and Tonnis, Sharp, lateral center edge, and neck shaft angles were measured. Presence of Shenton's line disruption, crossover, and posterior wall signs were recorded. Independent and paired t test, Wilcoxon signed-rank test, and χ test were used with a significance level at 0.05.

RESULTS

Out of 308 children with Down syndrome, there were 10 patients with 13 unstable hips and 13 patients with 26 stable hips who had computed tomographic or magnetic resonance imaging scans. Age and sex distributions were similar (P>0.3) with no difference in acetabular anteversion (P=0.926) between them. Twelve patients (6 boys and 6 girls) had reconstruction for 17 hips. The mean age was 9 years (3 to 15 y) and the mean follow-up was 7 years (1.2 to 17.6 y). Five hips were painful preoperatively and 1 hip was painful at last visit. Radiographic measurements improved significantly (P<0.05). Shenton's line disruption was found in fewer hips (P=0.001) at last visit with no difference in the crossover and posterior wall signs (P=0.177).

CONCLUSIONS

This report suggests that a wide range of acetabular anteversion measurements exist in children with Down syndrome. After detailed anatomic study of the hip, good results with a low complication rate can be expected over the intermediate term after hip reconstruction.

LEVEL OF EVIDENCE

Level IV-prognostic and therapeutic study.

Aneuploidy and skeletal health

The normal human chromosome complement consists of 46 chromosomes comprising 22 morphologically different pairs of autosomes and one pair of sex chromosomes. Variations in either chromosome number and/or structure frequently result in significant mental impairment and/or a variety of other clinical problems, among them, altered bone mass and strength. Chromosomal syndromes associated with specific chromosomal abnormalities are classified as either numerical or structural and may involve more than one chromosome. Aneuploidy refers to the presence of an extra copy of a specific chromosome, or trisomy, as seen in Down's syndrome (trisomy 21), or the absence of a single chromosome, or monosomy, as seen in Turner syndrome (a single X chromosome in females: 45, X). Aneuploidies have diverse phenotypic consequences, ranging from severe mental retardation and developmental abnormalities to increased susceptibility to various neoplasms and premature death. In fact, trisomy 21 is the prototypical aneuploidy in humans, is the most common genetic abnormality associated with longevity, and is one of the most widespread genetic causes of intellectual disability. In this review, the impact of trisomy 21 on the bone mass, architecture, skeletal health, and quality of life of people with Down syndrome will be discussed.

Successful closed reduction after adductor tenotomy in a 14-year-old boy with chronic hip dislocation in Down syndrome

Dislocation or subluxation of the hip is considered as the most common hip problem in patients with Down syndrome. Recommended treatment of chronic dislocation treatment is open reduction combined with femoral and/or pelvis osteotomies. We report a Down syndrome child with chronic hip dislocation who was successfully treated with adductor tenotomy and closed reduction, which has not been reported previously.

Management of hip instability in trisomy 21

The unstable hip in Trisomy 21 presents with a spectrum of hip instability with different problems at different ages. What links this multiphase problem, in many patients, is the final common pathway of untreated instability, that of a stiff, dislocated, and often-painful hip, leading to significant functional disability. Historically, the results of treating hip instability in Trisomy 21 were variable with a notable frequency of poor results. With an improved understanding of the Trisomy 21 hip in terms of its pathoanatomy and a more contemporary surgical approach to hip reconstruction, much improved results can be expected and indeed have recently been shown. The mainstay of treatment for the habitual dislocation group presenting before 8 years of age is the femoral varus derotation osteotomy. The older group presenting with painful subluxation often show signs of secondary acetabular dysplasia and thus are best treated with redirectional acetabular osteotomy with or without the use of femoral varus derotation osteotomy. The presence of radiographic features of degenerative arthritis in the fixed dislocation group precludes the use of joint-preserving techniques for hip reconstruction, and these patients can achieve excellent results with total joint arthroplasty. The natural history, historical results, assessment, treatment, and management of complications of hip instability in Trisomy 21 are addressed in this paper.

Surgical challenges and clinical outcomes of total hip replacement in patients with Down’s syndrome

Down’s syndrome is associated with a number of musculoskeletal abnormalities, some of which predispose patients to early symptomatic arthritis of the hip. The purpose of the present study was to review the general and hip-specific factors potentially compromising total hip replacement (THR) in patients with Down’s syndrome, as well as to summarise both the surgical techniques that may anticipate the potential adverse impact of these factors and the clinical results reported to date. A search of the literature was performed, and the findings further informed by the authors’ clinical experience, as well as that of the hip replacement in Down Syndrome study group. The general factors identified include a high incidence of ligamentous laxity, as well as associated muscle hypotonia and gait abnormalities. Hip-specific factors include: a high incidence of hip dysplasia, as well as a number of other acetabular, femoral and combined femoroacetabular anatomical variations. Four studies encompassing 42 hips, which reported the clinical outcomes of THR in patients with Down’s syndrome, were identified. All patients were successfully treated with standard acetabular and femoral components. The use of supplementary acetabular screw fixation to enhance component stability was frequently reported. The use of constrained liners to treat intra-operative instability occurred in eight hips. Survival rates of between 81% and 100% at a mean follow-up of 105 months (6 to 292) are encouraging. Overall, while THR in patients with Down’s syndrome does present some unique challenges, the overall clinical results are good, providing these patients with reliable pain relief and good function.

Cite this article: Bone Joint J 2013;95-B, Supple A:41–5.

Acetabular retroversion in Down syndrome

BACKGROUND

The management of the unstable Down syndrome hip is challenging, and there is controversy about the anatomic factors that may contribute to the instability. It has been our observation that children with Down syndrome often have a deficient posterior acetabular wall. This is different from other congenital acetabular dysplasia where the anatomic deficiency is typically anterolateral. These observations suggest that the acetabulum in Down syndrome hip dysplasia may be relatively retroverted. The purpose of this study was to determine the acetabular version in children with Down syndrome and compare this with matched controls from both normal and developmental dysplasia of the hip (DDH) populations.

METHODS

A cohort of Down patients treated surgically for acetabular dysplasia and/or hip instability was matched by age, sex, and side to a group of normal controls and compared with a cohort of patients who had undergone periacetabular osteotomy for DDH. For all patients, preoperative computed tomography scans were used to measure acetabular version through the joint center. Statistical differences were determined using analysis of variance with α=0.05.

RESULTS

We identified 16 subjects in each cohort. The average acetabular version in the normal control group was 13±5 degrees and in the DDH cohort was 21±7 degrees. In contrast, the mean version in the group of patients with Down syndrome was 2±11 degrees, indicating increased acetabular retroversion; this result was significantly different from both the normal group (P=0.02) and those with DDH (P<0.001). According to the criteria described by Tönnis for computed tomography measured retroversion, 10/16 patients with Down syndrome were severely retroverted compared with only 3/16 normal controls and 1/16 patients with DDH (P=0.002).

CONCLUSIONS

Patients with Down syndrome and hip instability seem to have more retroverted acetabula than normal controls and patients with DDH. In patients with Trisomy 21, axial imaging should be performed to evaluate acetabular version when planning the optimal corrective osteotomy for instability and/or acetabular deficiency.

LEVEL OF EVIDENCE

Level III (prognostic, retrospective case-control).

Rotational acetabular osteotomy for habitual hip dislocation with posterior acetabular wall deficiency in patients with Down syndrome

Hip dislocation associated with Down syndrome is relatively rare. Hip dislocation can progress to severe subluxation or habitual dislocation if the initial therapy is improperly performed. However, definitive treatment guidelines for conservative and surgical therapy for hip dislocation in patients with Down syndrome have not been established. This article describes a case of a 12-year-old girl with Down syndrome with nontraumatic habitual hip dislocation. Her hip joint was associated with acetabular dysplasia and hypoplasia of the posterior acetabular wall. Although conservative therapy was initially performed, no effects were observed. Rotational acetabular osteotomy and capsular plication were performed to reconstruct the posterior acetabular wall. No postoperative redislocation occurred, and the treatment effects were favorably sustained for 2 years. In Down syndrome, few cases of developmental dysplasia and hypoplasia of the posterior acetabular wall have been reported. In previous reports, these morphological abnormalities were rarely taken into consideration when determining the treatment strategy, and to our knowledge, no other reports demonstrate therapy involving rotational acetabular osteotomy for hip dislocation complicated with Down syndrome. Whether the acetabulum had posterior wall deficiency was thought to be important for conservative and surgical therapies in hip dislocation in patients with Down syndrome. Rotational acetabular osteotomy could be an effective surgical procedure for reconstruction of the acetabulum by posterolateral rotation of the osteotomized acetabulum.

Instability of the hip in patients with Down Syndrome: improved results with complete redirectional acetabular osteotomy

BACKGROUND

The treatment of hip instability in patients with Down syndrome is challenging, and the literature provides little data to guide treatment. The purpose of the present study was to evaluate our results with complete redirectional acetabular osteotomy and to compare these results with our experience with other procedures.

METHODS

We retrospectively evaluated all patients with Down syndrome who underwent surgery for the treatment of gross hip instability or symptomatic acetabular dysplasia with or without subluxation. Medical records were reviewed for symptoms and demographic information. On the basis of the primary procedure, the patients were separated into Group A (periacetabular or triple osteotomy) or Group B (varus femoral osteotomy with or without incomplete acetabuloplasty [e.g., Dega osteotomy or shelf acetabuloplasty]). Preoperative and latest postoperative radiographs were used to compare the extrusion index, the lateral center-edge angle, the Tönnis angle, and the continuity of the Shenton line. Preoperative computed tomography (CT) scans were measured for acetabular version.

RESULTS

We identified thirty-five hips (twenty-three patients), including twenty-five hips in Group A and ten in Group B. The mean age was 11.8 years, and the mean duration of follow-up was 5.3 years. Preoperatively, the acetabula were retroverted in both groups. Patients in Group A had worse initial hip pathology than those in Group B, as indicated by a higher mean extrusion index (50% compared with 33%; p = 0.06), a smaller center-edge angle (1° compared with 15°; p = 0.003), a larger Tönnis angle (21° compared with 10°; p = 0.001), and a smaller percentage of patients with an intact Shenton line (20% compared with 40%; p = 0.39). Most recent radiographs, however, showed superior results for Group A, including a lower mean extrusion index (10% compared with 29%; p < 0.0001), a larger center-edge angle (33° compared with 14°; p < 0.001), a smaller Tönnis angle (-1° compared with 10°; p < 0.001), and a larger percentage of patients with an intact Shenton line (88% compared with 70%; p = 0.32). Preoperatively, eighteen hips demonstrated gross instability: twelve were treated with either periacetabular osteotomy or triple innominate osteotomy, and all but one (92%) remained stable at the time of the latest follow-up. In contrast, six hips were treated with femoral osteotomy with or without incomplete acetabuloplasty, with only three (50%) remaining stable.

CONCLUSIONS

Complete redirectional acetabular osteotomies are successful for stabilizing the hip and for correcting acetabular dysplasia in patients with Down syndrome.

Femoral varus derotation osteotomy for the treatment of habitual subluxation and dislocation of the pediatric hip in trisomy 21: a 10-year experience

BACKGROUND

Habitual hip subluxation and dislocation are potentially disabling features of the trisomy 21 syndrome. We describe outcomes after a femoral varus derotation osteotomy to achieve and maintain hip stability and community ambulation.

METHODS

All individuals with trisomy 21, who underwent hip surgery at our institution between 1998 and 2008, were searched using the hospital databases. The clinical notes and radiographs were reviewed from presentation to final follow-up. Nine children (16 hips) aged below 10 years, were identified. All had a femoral varus derotation osteotomy with a target femoral neck-shaft angle (NSA) of 105 degrees and external rotation of < 20 degrees of the distal fragment. All were performed by the senior author.

RESULTS

Mean age at first known hip dislocation was 4.6 years (range, 4 to 5.2 y), mean age at surgery was 6.1 years (range, 5.2 to 7.0 y), and mean follow-up was 5.4 years (range, 3.8 to 7.1 y). Mean NSA fell postoperatively to 106.0 degrees (range, 103.1 to 110.2 degrees) from 166.7 degrees (range, 162.2 to 171.1 degrees). In 2 hips, intraoperative instability remained, requiring immediate periacetabular osteotomy and capsulorraphy.Postoperatively, all patients demonstrated an asymptomatic waddling gait, which persisted in 1 individual. Fourteen hips developed peritrochanteric varus deformities with a mean center of rotation and angulation of 21 degrees (range, 16 to 25 degrees). Two hips (12.5%) sustained implant-related fractures 4 and 8 years postoperatively. One hip (6.3%) developed arthritis and none had redislocated at latest follow-up.

CONCLUSIONS

Sequelae from recurrent subluxation or dislocation of hips in trisomy 21 may require surgery to prevent eventual disability.We recommend a varus producing proximal femoral osteotomy correcting the NSA to approximately 105 degrees. This should be performed before the age of 7 years or a widened or V-shape teardrop develops. After 2 implant-related fractures, we recommend implant removal once the osteotomy has healed and the hip stabilized.In our experience, this approach is effective in maintaining hip stability.

LEVEL OF EVIDENCE

A level 4 study, looking at a specific patient population undergoing a particular procedure.

Down syndrome: orthopedic issues

PURPOSE OF REVIEW

The purpose of this review is to update the role of the orthopedic surgeon in the management of Down syndrome as these patients are living longer and participating in sporting activities.

RECENT FINDINGS

Approximately 20% of all patients with Down syndrome experience orthopedic problems. Upper cervical spine instability has the most potential for morbidity and, consequently, requires close monitoring. Other conditions such as scoliosis, hip instability, patellar instability and foot problems can cause disability if left untreated. In some of these conditions, early diagnosis can prevent severe disability.

SUMMARY

Surgical intervention in children with Down syndrome has a high risk of complications, particularly infection and wound healing problems. Careful anesthetic airway management is needed because of the associated risk of cervical spine instability.

Down syndrome in children: the role of the orthopaedic surgeon

Down syndrome, the result of trisomy of chromosome 21, is one of the most common chromosomal abnormalities. Patients have a characteristic facial appearance, variable levels of intelligence and self-care skills, and a variety of associated medical conditions. Orthopaedic manifestations occur frequently; most are related to hypotonia, joint hypermobility, and ligamentous laxity. Atlanto-occipital and atlantoaxial hypermobility, as well as bony anomalies of the cervical spine, can produce atlanto-occipital and cervical instability. Methods of screening for this instability, particularly with regard to participation in sports, are a subject of controversy. Scoliosis, hip instability, slipped capital femoral epiphysis, patellar instability, and foot deformities are other musculoskeletal conditions found in patients with Down syndrome that can be challenging for the orthopaedic surgeon to treat.

Multidirectional habitual bilateral hip dislocation in a patient with Down syndrome

A multidirectional (anterior and posterior) bilateral habitual nontraumatic dislocation of the hip in a 3-year-old girl with Down syndrome is reported. The treatment was conservative with application of a spica cast for 12 weeks to shrink the capsule. During the first 6 weeks of treatment, the hips were immobilized in abduction and full external rotation. During the last 6 weeks, the hips were in abduction and slight internal rotation. After cast removal, the hips seemed to have been stabilized, and the child has remained asymptomatic for the last 12 months.

Periacetabular osteotomy in patients with Down’s syndrome

We treated eight dysplastic acetabula in six skeletally mature patients with Down’s syndrome by a modified Bernese periacetabular osteotomy. The mean age at the time of surgery was 16.5 years (12.8 to 28.5). Mean length of follow-up was five years (2 to 10.4).

Pre-operatively the mean (Tönnis) acetabular angle was 28°, the centre-edge angle was −9°, and the extrusion index was 60%; post-operatively they were 3°, 37°, and 17%, respectively. Two patients with post-operative (Tönnis) acetabular angles > 10° developed subluxation post-operatively and required secondary varus derotation femoral osteotomies. Another patient developed a late labral tear which was treated arthroscopically. All eight hips remain clinically stable, and are either asymptomatic or symptomatically improved.

These results suggest that the modified Bernese periacetabular osteotomy can be used successfully in the treatment of acetabular dysplasia in patients with Down’s syndrome.

Posterior acetabular wall deficiency in Down syndrome

Trisomy 21 or Down syndrome is the most common chromosomal anomaly and is associated with musculoskeletal abnormalities related to a generalized ligamentous laxity. Approximately 1% to 7% of Down syndrome patients have hip instability. Prior studies on the topic recommend Salter innominate osteotomy, capsular plication, and a varus derotational osteotomy of the proximal femur, which typically is in an anteverted and valgus position. The authors present a previously unreported bilateral finding in two patients noted on three-dimensional reconstruction computed tomography: deficiency of the posterior acetabular wall. Each was treated using a modification of the Pemberton osteotomy in which a wedge of iliac crest graft is placed posteriorly to hinge the posterior wall into a position of better posterior coverage of the femoral head. Both patients' hips have remained stable more than 10 years postoperatively. Follow-up imaging demonstrates well-remodeled osteotomy sites and excellent posterior coverage of the femoral heads.

Sports participation of children with Down syndrome

Patients with Down syndrome, by virtue of ligamentous laxity, are prone to a number of orthopedic problems with potentially serious sequelae. These disorders need to be evaluated throughout childhood and, when detected, appropriately managed. Given such management, the child with Down syndrome should be able to participate actively in and derive benefits from sports activities.