Radiographic analysis of movements of the acetabulum and the femoral head after Salter innominate osteotomy

Smith c/b ratio and teardrop figure measurements; Can it be used in the follow-up of patients who underwent salter innominate osteotomy?

BACKGROUND

This study aimed to investigate the effectiveness of radiological parameters used in the follow-up of patients who underwent salter innominate osteotomy (SIO) for the treatment of developmental dysplasia of the hip.

METHODS

Acetabular index, c/b ratio, teardrop width, femoral head teardrop distance (TDD), and acetabular teardrop angle were measured on anteroposterior pelvic radiographs of patients who underwent SIO between 2017 and 2020. The patients were divided into 2 groups according to their preoperative Tönnis stage. Twenty-five (51%) hips of 23 patients with Tönnis stage 2 were classified into group 1, and 24 (49%) of 17 patients with Tönnis stages 3 and 4 were classified into group 2. Changes in radiologic parameters over time and between the groups were statistically evaluated.

RESULTS

The study included 49 hips of 40 patients (37 female and 3 male). The age at surgery was 26.53 (18-53) months. After a mean follow-up period of 33.7 ± 12.8 months, there was no statistically significant difference between Groups 1 and 2 in terms of clinical, radiological and femoral head avascular necrosis results (P = .591, P = 956, P = .492). The changes in radiological parameters over time and between groups were statistically significant. (P < .001). Only the TDD and c/b ratio were significantly different between groups 1 and 2 (P = .002 and P < .001, respectively).

CONCLUSION

In our study, along with acetabular index, the c/b ratio, teardrop width, TDD, and acetabular teardrop angle significantly changed after SIO and could be used as a guide for patient follow-up.

Are the outcomes of single-stage open reduction and Dega osteotomy the same when treating DDH in patients younger than 8 years old? A prospective cohort study

BACKGROUND

The primary objective was to report our early results after a one-stage procedure [open reduction (OR), Dega pelvic osteotomy (DPO), and femoral osteotomy (FO) when needed] for surgical management of a cohort of patients with developmental dysplasia of the hip (DDH). The secondary objective was to compare the functional, radiological, and complications among patients younger and older than 30 months.

MATERIALS AND METHODS

This prospective cohort study included 71 hips with DDH in 61 patients with a mean age of 34.3 ± 19.5 months. All patients underwent one-stage surgical procedures, including OR + DPO and FO, if needed. Functional and radiographic assessment at the last follow-up was conducted using the modified Severin grading system and the Severin classification system, respectively, in addition to assessing the acetabular index (AI), osteotomies healing, and presence of complications. We divided patients into two groups, younger than 30 months (group I) and older than 30 months (group II).

RESULTS

We included 35 hips in group I and 36 in group II. All hips received OR + DPO, while 25 (69.4%) hips in group II had FO. The operative time was significantly longer in group II (103.19 ± 20.74 versus 72.43 ± 11.59 min, p < 0.001). After a mean follow up of 21.3 ± 2.3 months, the functional outcomes were satisfactory in 62 (87.3%) hips (94.3% in group I and 80.6% in group II, p = 0.35). There was a significant improvement in the AI in all patients compared with preoperative values (27.2° ± 2.9 versus 37° ± 4.2, p < 0.05). Furthermore, 63 (88.7%) hips had satisfactory radiographic outcomes (94.3% in group I and 83.3% in group II, p = 0.26), and all osteotomies showed radiographic healing. The overall complications incidence was significantly lower in group I compared with group II (5.7% versus 30.6%, p < 0.05), and avascular necrosis occurred in 4 (5.6%) hips, all in group II (p = 0.06).

CONCLUSION

One-stage procedure entailing open reduction, Dega pelvic osteotomy, and femoral osteotomy when needed for managing DDH in patients younger than eight years old revealed acceptable clinical and radiological outcomes. However, there was a higher need for a concomitant femoral osteotomy in patients older than 2.5 years, and complications were more frequent.

LEVEL OF EVIDENCE III

Prognostic value of bone resorption pattern in the anterior portion of the femoral head in Legg-Calvé-Perthes disease

Purpose

To examine whether differences in bone resorption patterns in the anterior portion of the femoral head correlate with the prognosis of Legg-Calvé-Perthes disease.

Methods

Seventy-eight patients with unilateral Legg-Calvé-Perthes disease, who were diagnosed after 6.0 years of age, underwent the Salter innominate osteotomy from 1987 to 2013, and were followed up to skeletal maturity. The anterior bone resorption pattern of the femoral head was evaluated from a frog-leg lateral hip radiograph made in the middle of the fragmentation period, and classified into two types, an epiphysis-preserved type (P) and a physis-disrupted type (D). The correlation between the type of bone resorption and the Stulberg outcome was analyzed.

Results

The Stulberg outcomes were grade I for 9 patients, grade II for 31, grade III for 35, and grade IV for 3, with a mean follow-up period of 8.3 ± 2.7 years. Fifty-one patients demonstrated the type P hips and 27 did the type D hip. In a subset analysis of patients with the modified lateral pillar group-B hips in the younger group (6.0-8.9 years of age at diagnosis), the percentages of the favorable and unfavorable outcomes significantly differed between the two types (p = 0.013). Anteroposterior enlargement of the affected femoral head was significantly greater in the type D hips than the type P hips (p = 0.014).

Conclusion

Unfavorable hip morphology at skeletal maturity can be predicted in patients with the lateral pillar group-B hips by focusing on bone resorption patterns of the anterior portion of the femoral head.

Level of evidence

Level III, prognostic study.

Appropriate Surgical Timing of Salter Innominate Osteotomy for Residual Acetabular Dysplasia in Children

BACKGROUND

Salter innominate osteotomy (SIO) provides favorable results for treating residual acetabular dysplasia in young children. In this study, we examined the midterm results of SIO according to the age at surgery to determine the optimal timing of this procedure.

METHODS

We retrospectively examined 50 hips of 42 patients (8 boys and 34 girls) with acetabular dysplasia who underwent SIO and were followed up until skeletal maturity. The center-edge angle (CEA) was measured based on the anteroposterior radiographs of the hip obtained before surgery, 5 weeks after surgery, and at the latest follow-up. Severin classification was evaluated at the latest follow-up. Patients were categorized into 3 groups according to age at surgery: younger than 7 years of age (group A), 7 to 8 years of age (group B), and 9 years of age or older (group C).

RESULTS

The mean preoperative CEA level of 0.9 degrees improved to 17.1 degrees postoperatively, which was increased to 28.1 degrees at the latest examination. Overall, 45 hips (90%) were classified as Severin I or II, with 96% in group A, 94% in group B, and 57% in group C. In group C, postoperative acetabular coverage was similar to that in the other groups (16.6 degrees in group A, 14.8 degrees in group B, and 18.1 degrees in group C), although the final outcome was unsatisfactory. The average improvement in CEA from postoperative to skeletal maturity was significantly smaller in group C than in the other groups (12.7 degrees in group A, 11.3 degrees in group B, and 3.0 degrees in group C).

CONCLUSIONS

SIO showed favorable outcomes with satisfactory acetabular coverage at skeletal maturity. However, satisfactory acetabular coverage could not be obtained in some older patients because of limited postoperative remodeling capacity and smaller secondary improvement of CEA. We recommend that SIO should be performed in patients aged 8 years or younger.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Salter pelvic osteotomy for the treatment of Developmental Dysplasia of the Hip: assessment of postoperative results and risk factors

BACKGROUND

If non-surgical treatment of Developmental Dysplasia of the Hip (DDH) fails or if DDH is late-detected, surgery is necessary. Salter pelvic osteotomy (SPO) is an effective surgical option for such cases.

OBJECTIVES

To study the results after SPO; to evaluate risk factors; to reveal radiological parameters that may correlate with results.

METHODS

Results analysis in 17 patients (22 hips). Risk factors included those that do not depend on the surgeon (patient's age, value of the acetabular index (AI) preoperatively, DDH Tonnis grade) and those that depend on the surgeon (amount of AI correction). To radiological parameters which may correlate with the amount of AI correction we referred distance "d" and the lateral rotation angle.

RESULTS

SPO allows performing AI correction in ranges 24.1 ± 6.5°. Excellent and good clinical results were obtained in 95.5% of patients; excellent and good radiological results in 86.4% of patients. Risk factors that do not depend on the surgeon were older patient's age and higher preoperative AI values (p <0.05). The risk factor that depends on the surgeon was the amount of AI correction (p <0.05). The distance "d" was recognized as a radiological parameter that may indicate sufficient AI correction (p <0.05).

CONCLUSION

In older patients with a higher preoperative AI value the results will be predictably worse. The surgeon may influence the result with a greater amount of AI correction (which may also be indicated radiologically by the distance "d" values).

LEVEL OF EVIDENCE

IV, therapeutic, case series.

Angulated Salter osteotomy in the treatment of developmental dysplasia of the hip

Salter osteotomy is widely used to improve acetabular coverage in the treatment of developmental dysplasia of the hip. Herein we describe angulated Salter osteotomy (ASO) as the modified Salter osteotomy, which creates a two-point contact between the proximal and distal fragments and better stabilizes the fixation of the fragments. We reported our results of ASO and compared it with that of Salter osteotomy performed previously by us. We retrospectively reviewed 41 unilateral hips that underwent ASO, with no other accompanying procedures, between 2012 and 2018. We investigated the radiographic measurements included the preoperative values of the acetabular index and center-edge angle (CEA), immediate postoperative values of distance d (lateral displacement of the distal fragment), lateral rotation angle (LRA), the ratio of the obturator height (ROH), pelvic height increase percentage (PHIP) and the values of acetabular index and CEA during the last follow-up. Measurements were compared with 20 unilateral hips that underwent Salter osteotomy. The mean age at the time of surgery was 5.4 years, and the mean follow-up duration was 3.3 years. Immediately after surgery, the mean distance d, LRA, ROH and PHIP were 8 mm, 19°, 70 and 1%, respectively. The last follow-up values of acetabular index and CEA significantly improved from the preoperative values by 18° and 21°, respectively. Patients treated with ASO showed significantly larger distance d, more improvement in CEA, and lesser PHIP than those treated with Salter osteotomy. The short-term outcomes of ASO are favorable. ASO was as effective as or better than Salter osteotomy in pulling out and stabilizing the distal fragment anterolaterally. ASO prevents elongation of the ilium, which causes pelvic obliquity.

How does former Salter innominate osteotomy in patients with Legg–Calvé–Perthes disease influence acetabular orientation? An MRI-based study

Salter innominate osteotomy (SIO) has been successfully used in the treatment of Legg–Calvé–Perthes disease (LCPD). Recent studies that have raised concerns about acetabular retroversion after SIO have been based on plain radiographs. In order to assess the true acetabular orientation, the present study uses a specific magnetic resonance imaging (MRI) technique. In addition, the association between acetabular morphology and clinical function as well as health-related quality of life was assessed. Twenty-three patients with 24 operated hips who underwent SIO for LCPD between January 2004 and November 2014 were included. Mean age was 8.5 ± 2.2 years at surgery and 18.5 ± 2.9 years at follow-up. MRIs were conducted at 1.5 T using radial sequences. The analysis included the acetabular version, acetabular sector angles (ASAs) and alpha angles. Plain radiographs were used in order to obtain the Stulberg classification. Patient-related outcome measures included the international Hip Outcome Tool and Euroqol-5 dimensions scores. In comparison to the non-operated side, the MRI of previously operated hips showed no difference of version at the center of the femoral head but significantly decreased version just below the roof level. As a marker for posterior acetabular coverage, the ASAs between 9 and 11 o’clock were significantly decreased when compared with non-operated hips. In hips with a mild acetabular retroversion (<15°), the function was significantly decreased when compared with non-retroverted hips. The SIO is an effective tool in order to restore acetabular containment in LCPD. When compared with the non-operated hips, our collective displays only moderate changes of acetabular orientation and coverage.

Efficacy Evaluation of 3D Navigational Template for Salter Osteotomy of DDH in Children

Background

The aim of this study is to retrospectively evaluate the efficacy of 3D navigational template for Salter osteotomy of DDH in children.

Methods

Thirty-two consecutive patients with DDH who underwent Salter osteotomy were evaluated between July 2014 and August 2017, and they were divided into the conventional group (n = 16) and navigation template group (n = 16) according to different surgical methods. The corrective acetabular degrees, radiation exposure, and operation time were compared between the two groups.

Results

No nerve palsy or redislocation was reported in the navigation template group. Compared with the conventional group, the navigation template group had the advantages of more accurate acetabular degrees, less radiation exposure, and shorter operation time (P < 0.05). Meanwhile, the navigation template group achieved a better surgical outcome than the conventional group (McKay, P = 0.0293; Severin, P = 0.0949).

Conclusions

The 3D navigational template for Salter osteotomy of DDH is simple and effective, which could be an alternative approach to improve the Salter osteotomy accuracy and optimize the efficacy.

Comparison of surgical and nonsurgical containment methods for patients with Legg-Calvé-Perthes disease of the onset ages between 6.0 and 8.0 years: Salter osteotomy versus a non-weight-bearing hip flexion-abduction brace

Since bone healing potential decreases with age, patients with Legg-Calvé-Perthes disease should receive treatment appropriate to their age group. Nonsurgical treatment is commonly applied to patients under 6.0 years of age at the onset and surgical treatment is recommended for those over 8.0 years of age, but it remains unclear which is better for those between 6.0 and 8.0 years. The aim of this retrospective study was to compare outcomes of Salter osteotomy and a non-weight-bearing brace in this age group. Inclusion criteria were unilateral Legg-Calvé-Perthes disease patients who were 6.0-8.0 years of age at the onset, who had more than 50% femoral head involvement without hinge abduction, and who underwent either Salter osteotomy (n = 35) or a non-weight-bearing hip flexion-abduction brace (n = 18). Radiological and clinical outcomes at skeletal maturity were compared between the two groups. The mean follow-up durations were 9.4 years in the Salter osteotomy group and 10.0 years in the brace group. There was no significant difference in the modified Waldenström classification at the beginning of treatment and the Catterall and modified lateral pillar classifications evaluated at the fragmentation stage between the groups. At skeletal maturity, the Stulberg classification, the sphericity deviation score, femoral head overgrowth, and the articulo-trochanteric distance were similar between the groups, but the Salter osteotomy group showed significantly smaller lateralization of the femoral head and better acetabular shape and coverage than the brace group: femoral head lateralization (P < 0.001), acetabular depth-to-width ratio (P = 0.002), Sharp angle (P < 0.001), lateral acetabular shape (P = 0.027), acetabular head index (P < 0.001). There was no significant difference in hip pain and motion between the groups. In this age group, Salter osteotomy provides better femoral head position and acetabular shape and coverage than a non-weight-bearing brace.

Clinical and radiological outcomes of combined acetabuloplasty with acetabular redirectional osteotomy and femoral shortening for children older than 9 years of age with developmental dysplasia of the hip: a retrospective case series

Developmental dysplasia of the hip (DDH) is a challenging pediatric condition. This study aimed to investigate the feasibility and the efficacy of Dega osteotomy in combination with pelvic triple osteotomy or periacetabular osteotomy and femoral shortening with derotational osteotomy for the treatment of severe acetabular deformity secondary to DDH in children older than 9 years of age. The clinical data of 22 children treated at our institution were retrospectively collected. Pre- and postoperative hip radiographs were evaluated. Center-edge (CE) angle was measured, and Severin classification and McKay criteria were used to evaluate the final outcome. Twenty-two patients (including 21 female patients) were treated during the study period. The mean age was 10.9 years (range 9.1-14.8). All patients had preoperative Tonnis grades III and IV dislocated hips. Mean follow-up time was 25.7 months (range 14-48). All but three hips underwent open reduction. All had concomitant proximal femoral shortening and derotation osteotomy. At last follow-up visit, all hips remained located and no cases of avascular necrosis were recorded. All patients had Severin grade I-II hips at last follow-up. According to McKay criteria, clinical outcome was excellent in three patients, good in seven, and fair in 12 patients. Acetabuloplasty in combination with periacetabular osteotomy and femoral shortening with derotational osteotomy is a valid and effective treatment for children older than 9 years of age with severe acetabular deformity secondary to DDH. Although the early clinical outcome of the reported procedure is favorable, further studies are necessary to evaluate the long-term effects of the reported technique.

Proposal of a New Type of Innominate Osteotomy without the Use of Bone Graft in Children: A Preliminary Study

Good long-term outcomes have been reported for the Salter innominate osteotomy (SIO), which is widely used to correct developmental dysplasia of the hip (DDH) in children. In this study, we describe the procedure and early outcomes of a new pelvic osteotomy termed "angulated innominate osteotomy" (AIO).

METHODS

Twenty-one patients (22 hips) underwent AIO. We evaluated age at the time of surgery, operative time, blood loss, and time to bone union. Several radiographic parameters were assessed preoperatively, immediately postoperatively, and at the time of the latest examination. Measurements were compared with those of 20 previous patients who underwent SIO. The AIO is made to form an isosceles triangle. This enables 2 points of contact between the proximal and distal bone fragments, eliminating the need for a bone graft.

RESULTS

Mean age at the time of surgery was 5.9 years, and the mean duration of follow-up was 30.8 months. The mean operative time was 103 minutes, mean blood loss was 33 mL, and mean time to bone union was 9.8 weeks. Immediately postoperatively, the mean "distance d" (lateral displacement of the distal fragment), mean ratio of the obturator heights (ROH), and mean lateral rotation angle (LRA) were 7.2 mm, 70.4%, and 19.3°, respectively. At the latest examination, the mean acetabular index (AI), center-edge angle (CEA), and acetabular head index (AHI) were 16.4°, 23.7°, and 85.5%, respectively, each of which were significantly improved compared with the preoperative values. Moreover, the mean postoperative iliac length difference (ILD) between the operative and contralateral sides was only 0.1 mm. Those treated with AIO had a significantly shorter operative time and time to bone union, and less blood loss, than those treated with SIO. The mean distance d, ROH, and LRA did not differ significantly from SIO results, while the mean ILD was significantly less.

CONCLUSIONS

AIO is a less-invasive procedure that does not require a bone graft, and the short-term outcomes were favorable. Sufficient coverage of the acetabulum with displacement of the distal bone fragment to an extent similar to SIO can be achieved; we consider AIO a worthy surgical procedure that has the potential to provide good long-term outcomes similar to those seen with SIO.

LEVEL OF EVIDENCE

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

Innominate Salter osteotomy using resorbable screws: a retrospective case series and presentation of a new concept for fixation

PURPOSE

The Salter innominate osteotomy (SIO) in children is traditionally stabilized by Kirschner-wires, which have issues regarding stability, infection and the need to be extracted. To counter these disadvantages, we present a surgical method to stabilize SIO with modern resorbable poly lactic-co-glycolic acid screws. Using a case series of 21 patients treated with SIO for developmental dysplasia of the hip or Legg-Calvé-Perthes disease we evaluate the feasibility of the method.

METHODS

The integrity of the osteotomy was interpreted by radiological measurements of acetabular index, centre-edge angle and Reimer's index. Perioperative and postoperative complications were evaluated.

RESULTS

Radiographic evaluation revealed a stable osteotomy and favourable development in all measured parameters with the exception of one patient who fell out of bed the first day postoperatively. No other perioperative surgical complications were observed and there were no local reactions to the resorbable screws.

CONCLUSION

Modern resorbable screws carry multiple benefits both for the patient and the surgeon. In our case series the implants provided sufficient stability and the implants caused no local reactions. The use of resorbable implants gave the surgeon a wider range of possible screw placements and avoided the need for implant removal.

LEVEL OF EVIDENCE

Level IV - Case series.

Effect of high tibial osteotomy on hip biomechanics in patients with genu varum: A prospective cohort study

Background and aims

The aim of this study is to evaluate the effect of proximal tibia osteotomy on hip biomechanics.

Methods

This cohort study was conducted on 50 knees of 37 patients divided into two groups of unilateral and bilateral surgeries during 2015–2016. Patients underwent medial open-wedge osteotomy of proximal tibia. Axial alignment of lower limb radiography was carried out for the patients before and after the osteotomy.

Results

Findings from unilateral and bilateral high tibial osteotomies demonstrated that the average of greater trochanter (GT) angle from femoral head center and also the average angle of knee varus were significantly decreased (P = 0.001). Although not statistically significant, the average angle of the mechanical axis of lower limb showed an increase in unilateral osteotomy (P = 0.889) and a decrease in bilateral osteotomy (P = 0.887). The average angle of pelvic obliquity after unilateral osteotomy increased significantly (P = 0.001) but showed no statistically significant difference in bilateral osteotomy (P = 0.631).

Conclusion

High tibial osteotomy significantly affects the GT and causes the downward replacement of GT and consequent shortening of the abductors moment arm, increased hip joint reaction force, and reduction of the shear force on the femoral neck.

Developmental dysplasia of the hip: What has changed in the last 20 years?

Developmental dysplasia of the hip (DDH) describes the spectrum of structural abnormalities that involve the growing hip. Early diagnosis and treatment is critical to provide the best possible functional outcome. Persistence of hip dysplasia into adolescence and adulthood may result in abnormal gait, decreased strength and increased rate of degenerative hip and knee joint disease. Despite efforts to recognize and treat all cases of DDH soon after birth, diagnosis is delayed in some children, and outcomes deteriorate with increasing delay of presentation. Different screening programs for DDH were implicated. The suspicion is raised based on a physical examination soon after birth. Radiography and ultrasonography are used to confirm the diagnosis. The role of other imaging modalities, such as magnetic resonance imaging, is still undetermined; however, extensive research is underway on this subject. Treatment depends on the age of the patient and the reducibility of the hip joint. At an early age and up to 6 mo, the main treatment is an abduction brace like the Pavlik harness. If this fails, closed reduction and spica casting is usually done. After the age of 18 mo, treatment usually consists of open reduction and hip reconstruction surgery. Various treatment protocols have been proposed. We summarize the current practice for detection and treatment of DDH, emphasizing updates in screening and treatment during the last two decades.

Does Salter innominate osteotomy predispose the patient to acetabular retroversion in adulthood?

BACKGROUND

Salter innominate osteotomy has been identified as an effective additional surgery for the dysplastic hip. However, because in this procedure, the distal segment of the pelvis is displaced laterally and anteriorly, it may predispose the patient to acetabular retroversion. The degree to which this may be the case, however, remains incompletely characterized.

QUESTIONS/PURPOSES

We asked, in a group of pediatric patients with acetabular dysplasia who underwent Salter osteotomy, whether the operated hip developed (1) acetabular retroversion compared with contralateral unaffected hips; (2) radiographic evidence of osteoarthritis; or (3) worse functional scores. (4) In addition, we asked whether femoral head deformity resulting from aseptic necrosis was a risk factor for acetabular retroversion.

METHODS

Between 1971 and 2001, we performed 213 Salter innominate osteotomies for unilateral pediatric dysplasia, of which 99 hips (47%) in 99 patients were available for review at a mean of 16 years after surgery (range, 12-25 years). Average patient age at surgery was 4 years (range, 2-9 years) and the average age at the most recent followup was 21 years (range, 18-29 years). Acetabular retroversion was diagnosed based on the presence of a positive crossover sign and prominence of the ischial spine sign at the final visit. The center-edge angle, acetabular angle of Sharp, and acetabular index were measured at preoperative and final visits. Contralateral unaffected hips were used as controls, and statistical comparison was made in each patient. Clinical findings, including Harris hip score (HHS) and the anterior impingement sign, were recorded at the final visit.

RESULTS

Patients were no more likely to have a positive crossover sign in the surgically treated hips (20 of 99 hips [20%]) than in the contralateral control hips (17 of 99 hips [17%]; p = 0584). In addition, the percentage of positive prominence of the ischial spine sign was not different between treated hips (22 of 99 hips [22%]) and contralateral hips (18 of 99 hips [18%]; p = 0.256). Hips that had a positive crossover or prominence of the ischial spine sign in the operated hips were likely also to have a positive crossover sign or prominence of the ischial spine sign in the unaffected hips (16 of 20 hips [80%] crossover sign, 17 of 22 hips [77%] prominence of the ischial spine sign). At the final visit, five hips (5%) showed osteoarthritic change; one of the five hips (20%) showed positive crossover and prominence of the ischial spine signs, and the remaining four hips showed negative crossover and prominence of the ischial spine signs. There was no significant difference in HHS between the crossover-positive and crossover-negative patient groups nor in the prominence of the ischial spine-positive and prominence of the ischial spine-negative patient groups (crossover sign, p = 0.68; prominence of the ischial spine sign, p = 0.54). Hips with femoral head deformity (25 of 99 hips [25%]) were more likely to have acetabular retroversion compared with hips without femoral-head deformity (crossover sign, p = 0.029, prominence of the ischial spine sign, p = 0.013).

CONCLUSIONS

Our results suggest that Salter innominate osteotomy does not consistently cause acetabular retroversion in adulthood. We propose that retroversion of the acetabulum is a result of intrinsic development of the pelvis in each patient. A longer-term followup study is needed to determine whether retroverted acetabulum after Slater innominate osteotomy is a true risk factor for early osteoarthritis. Femoral head deformity is a risk factor for subsequent acetabular retroversion.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Factors associated with an unfavourable outcome after Salter innominate osteotomy in patients with unilateral developmental dysplasia of the hip: does occult dysplasia of the contralateral hip affect the outcome?

Salter innominate osteotomy is an effective reconstructive procedure for the treatment of developmental dysplasia of the hip (DDH), but some children have a poor outcome at skeletal maturity. In order to investigate factors associated with an unfavourable outcome, we assessed the development of the contralateral hip. We retrospectively reviewed 46 patients who underwent a unilateral Salter osteotomy at between five and seven years of age, with a mean follow-up of 10.3 years (7 to 20). The patients were divided into three groups according to the centre-edge angle (CEA) of the contralateral hip at skeletal maturity: normal (> 25°, 22 patients), borderline (20° to 25°, 17 patients) and dysplastic (< 20°, 7 patients). The CEA of the affected hip was measured pre-operatively, at eight to nine years of age, at 11 to 12 years of age and at skeletal maturity. The CEA of the affected hip was significantly smaller in the borderline and dysplastic groups at 11 and 12 years of age (p = 0.012) and at skeletal maturity (p = 0.017) than in the normal group. Severin group III was seen in two (11.8%) and four hips (57.1%) of the borderline and dysplastic groups, respectively (p < 0.001). Limited individual development of the acetabulum was associated with an unfavourable outcome following Salter osteotomy.

Outcomes of modified Dega acetabuloplasty in acetabular dysplasia related to developmental dislocation of the hip

Developmental dislocation of the hip (DDH) is frequently, even after reduction, associated with residual acetabular dysplasia. Various surgical techniques are used to correct this, one of which is Dega acetabuloplasty. This osteotomy technique has, however, rarely been assessed in this particular indication. The present study therefore sought to describe the technical details, report clinical and radiological results, and present limitations.

HYPOTHESIS

Unlike reorientation osteotomy in children, Dega acetabuloplasty does not lead to a high rate of acetabular retroversion at the end of growth.

PATIENTS AND METHODS

Sixteen Dega acetabuloplasties in 15 patients were assessed on joint range of motion, limp, lower limb length discrepancy and impaired everyday activity, pre-operatively and at end of follow-up. Hips were classified following Wicart et al. (2003). Radiologic assessment comprised Wiberg angle and acetabular index, pre- and post-operatively and at follow-up. Acetabular retroversion was analyzed by crossover sign, and hips were classified following Severin.

RESULTS

Median age at surgery was 3 years (range, 1.1-12.2 years) and 10 years (6.4-17.8) at end of follow-up. At end of follow-up, all hips were pain-free and classified as Wicart A, and all activities were allowed. Radiologically, hips were classified as Severin I, II or IV, in 11 (68.5%), 4 (25%) and 1 (6.5%) cases respectively. Wiberg angle rose from a mean 3.3° (-30° to 30°) to 23° (10° to 38°) and acetabular index fell from a mean 31° (25° to 45°) to 20° (5° to 30°) with surgery, and both continued to improve over follow-up: 26° (12-45°) and 13° (3-24°) respectively (P<0.05). Acetabular retroversion was found in 2 of the 10 hips with Y cartilage fusion.

DISCUSSION

Modified Dega acetabuloplasty was effective in correcting acetabular dysplasia in DDH. Functional and radiological results were good, with a low rate of acetabular retroversion (2/10), unlike with other techniques.

LEVEL OF EVIDENCE

Level IV. Therapeutic study.

Long-term outcome of gradual reduction using overhead traction for developmental dysplasia of the hip over 6 months of age

BACKGROUND

In children over 6 months of age with developmental dysplasia of the hip (DDH), achieving a concentrically reduced hip while avoiding avascular necrosis (AVN) is challenging. The utility of gradual reduction (GR) using traction has insufficient evidence. We therefore report the long-term outcome of GR using overhead traction (OHT).

METHODS

We retrospectively reviewed 67 patients with DDH (75 hips) treated with GR using OHT over 6 months of age. The age at reduction ranged from 7 months to 4 years. All patients were followed up until skeletal maturity with a mean duration of 15.6 years. Pelvic radiographs were used to assess AVN, acetabular development, and the Severin classification. We determined the factors affecting the outcome at skeletal maturity.

RESULTS

Seventy-two hips (96%) were successfully reduced, 2 required subsequent closed reduction and 1 underwent open reduction. AVN occurred in 2 hips (2.7%). Among 48 hips (64%) with residual acetabular dysplasia, 31 were treated with Salter innominate osteotomy (SIO) between 5 and 6 years of age. Finally, 62 hips (82.7%) showed satisfactory outcome (56 in Severin class I and 6 in class II), whereas 13 showed unsatisfactory outcome (class III). Although we found no significant factors affecting the outcome, most of the hips treated with SIO were included in the satisfactory group.

CONCLUSIONS

GR using OHT could effectively minimize the risk of developing AVN in patients with DDH over 6 months of age at presentation. SIO at preschool age may play a beneficial role in the long-term outcome of GR using OHT.