Surgical treatment of the dysplastic acetabulum in adolescence

Open treatment of dysplasia-other than PAO: does it have to be a PAO?

Hip dysplasia is a developmental disorder that results in anatomic abnormalities in which the acetabular coverage is insufficient. In the absence of severe degenerative changes, younger active patients with these symptomatic structural abnormalities are increasingly managed with joint-preserving operations. Historically there have been numerous reconstructive pelvic osteotomies. In recent years, the Bernese periacetabular osteotomy (PAO) has become the preferred osteotomy by many surgeons. Even so, as our understanding of the hip advances and new diagnostic and treatment techniques are developed, we sought to put a focus on the long-term results of augmental osteotomies and pelvic osteotomies other than the PAO, to see if any of these surgeries still have a place in the current algorithm of treatment for the dysplastic hip. As the longevity of the treatment is the focal point for joint preservation surgeries for the dysplastic hip, these authors have searched databases for articles in the English literature that reported results of long-term follow-up with a minimum of 11-year survivorship after surgical treatment of developmental dysplasia of the hip. Reconstruction osteotomies for the dysplastic hip are intended to restore normal hip anatomy and biomechanics, improve symptoms and prevent degenerative changes, in this manuscript each procedure is independently assessed on the ability to achieve these important characteristics.

Neglected, developmental hip dislocation treated with external iliofemoral distraction, open reduction, and pelvic osteotomy

Between 1995 and 2003, we operated upon 18 children with 20 hips involved, aged 5-11 years (average: 7.5 years) suffering from an inveterate high developmental dislocation of the hip joint. An average follow-up period of our middle-term study was 51 months (range: 34-96 months). A two-staged management was applied. First, femoral head was lowered back to the level of acetabulum with an external fixator or a distractor device. The second stage involved open reduction combined with pelvic osteotomy and, in four cases with femoral derotation osteotomy. We noted two cases of avascular necrosis. Equal limb length was achieved in 15 cases. There were two cases of 0.5-cm length discrepancy, two cases of 1-cm length inequalities, and one case of 5-cm limb shortening. We endorse this method in neglected cases of previously untreated unilateral high developmental hip dislocations in children aged 8-10 years. It results in a usable hip joint without the need of femoral shaft shortening and facilitates future joint replacement.

A shelf procedure at a follow-up of 75 years

Developmental dysplasia of the hip predisposes to premature degenerative hip disease. A number of operations have been described to improve acetabular cover and have achieved varying degrees of success. We present the case of an 84-year-old woman, who underwent a shelf procedure to reconstruct a dysplastic hip 75 years ago. To date, the shelf remains intact and the hip is asymptomatic. We believe this represents the longest documented outcome of any procedure to stabilise the hip.

Slotted acetabular augmentation, alone or as part of a combined one-stage approach for treatment of hip dysplasia in adolescents with cerebral palsy: results and complications in 19 hips

BACKGROUND

Surgical correction for the challenging combined deformities in hip dysplasia associated with cerebral palsy remains controversial. The purpose of this study was to assess the efficacy and determine the role of slotted acetabular augmentation (SAA) for the treatment of neuromuscular hip dysplasia in comparison with other treatment options.

METHODS

We retrospectively analyzed 19 dysplastic hips in 19 patients with cerebral palsy who underwent SAA, alone or as part of a combined 1-stage approach, consisting of soft tissue lengthening and/or a proximal femoral osteotomy, during a 20-year period.

RESULTS

The mean age at the time of operation was 14 years and 7 months (range: 12 to 17 years and 11 months). All had a closed triradiate cartilage. In 13 hips, preoperative radiographs showed major aspheric femoral head deformities. All had subluxation or dislocation of the hip and severe acetabular dysplasia, associated with a painful hip in 15 patients. Before operation, the mean migration index was 64+/-18%, the mean Sharp angle was 51+/-4 degrees, and the mean center-edge angle was -4+/-13 degrees. On immediate postoperative radiographs, they were 3+/-5%, 35+/-5 degrees, and 42+/-11 degrees. At final follow-up, the average migration index was 10+/-8%, the mean Sharp angle was 35+/-6 degrees, and the mean center-edge angle was 39+/-13 degrees. Eleven hips required soft tissue lengthening and 5 hips had a proximal femoral osteotomy at the time of the shelf procedure. At the latest follow-up (mean duration: 5 years and 5 months), 16 of the 19 hips remained anatomically reduced.

CONCLUSIONS

Our results suggest that SAA is a successful procedure to treat advanced neurogenic acetabular dysplasia with or without femoral head deformities in skeletally mature patients.

Shelf acetabuloplasty for children with Perthes’ disease and reducible subluxation of the hip

We evaluated radiological hip remodelling after shelf acetabuloplasty and sought to identify prognostic factors in 25 patients with a mean age of 8.9 years (7.0 to 12.3) who had unilateral Perthes’ disease with reducible subluxation of the hip in the fragmentation stage.

At a mean follow-up of 6.7 years (3.2 to 9.0), satisfactory remodelling was observed in 18 hips (72%). The type of labrum in hip abduction, as determined by intra-operative dynamic arthrography, was found to be a statistically significant prognostic factor (p = 0.012).

Shelf acetabuloplasty as containment surgery seems to be best indicated for hips in which there is not marked collapse of the epiphysis and in which the extruded epiphyseal segment slips easily underneath the labrum on abduction, without imposing undue pressure on the lateral edge of the acetabulum.

Long-term results after closed reduction of latedetected hip dislocation: 60 patients followed up to skeletal maturity

BACKGROUND

This retrospective study was undertaken because there is limited knowledge about the long-term results after closed reduction of late-detected hip dislocation. The aims were to evaluate the outcome after skeletal maturity and to find predictive factors for good and poor results.

PATIENTS AND METHODS

The material included 60 patients (78 hips, 53 girls) treated during the period 1958-62. The primary treatment was skin traction for 36 (16-76) days. Closed reduction was performed in all hips except 4 that needed open reduction. The mean age at reduction was 20 (4-65) months. Hip spica plaster was worn for 9 (6-20) months. Within 3 years of the start of treatment, derotation femoral osteotomy was performed because of increased femoral anteversion in 35 patients. Later, 28 patients underwent additional surgery on the femur or acetabulum to improve femoral head coverage. Radiographs at the time of diagnosis and during follow-up to skeletal maturity were assessed. The average age of the patients at the most recent follow-up was 26 (15-42) years.

RESULTS

The femoral head coverage normalized during the primary treatment and then decreased somewhat during the remaining growth period. The dysplasia of the acetabulum improved markedly during the first year after reduction. It continued to improve, but to a much lesser degree, until 8-10 years of age. A satisfactory radiographic outcome at skeletal maturity (Severin grades I and II) was obtained in 63% of the hips. Early derotation osteotomy of the femur did not improve the outcome. Avascular necrosis of the femoral head occurred in 14% of the hips. Risk factors for unsatisfactory outcome at skeletal maturity were high initial dislocation, steep acetabulum 1 year after reduction, reduced femoral head coverage at age 8-10 years, and avascular necrosis.

INTERPRETATION

The specific risk factors and the radiographic outcome--with satisfactory long-term results in nearly two-thirds of the patients--would be valuable for comparison with outcome studies after more modern treatment regimes.

Comparison between Salter's innominate osteotomy and augmented acetabuloplasty in the treatment of patients with severe Legg-Calvé-Perthes disease. Analysis of 90 hips with special reference to roentgenographic sphericity and coverage of the femoral head

This is a roentgenographic and retrospective study comparing the results of two different operative procedures used in the treatment of Legg-Calvé-Perthes disease: Salter innominate osteotomy, and Augmented Acetabuloplasty. Group I comprised 43 patients (50 hips) who underwent Salter osteotomy. Another 40 patients (40 hips) were treated by Augmented Acetabuloplasty and formed Group 2. In Group 1, 11 (25.58%) patients were girls and 32 (74.42%) were boys. In Group 2, there were 4 (10%) girl and 36 (90%) boy patients. The average age was 6.62 years in Group 1 and 6.35 years in Group 2. Follow-up varied from 2 years to 10 years in both Groups 1 and 2. In Group 1, 18 (36%) hips were in the stage of necrosis, 28 (56%) in fragmentation, and 4 (8%) in reossification; in Group 2, 16 (40%) hips were in necrosis, 23 (57.5%) in fragmentation, and only 1 (2.5%) in reossification. All hips in necrosis were included in Salter and Thompson group B; all hips in fragmentation were classed as Catterall group 3 or 4. Preoperative arthrographs of the 50 hips in Group I were graded according to Laredo: 29 (58%) in group III, 18 (36%) in group IV, and 3 (6%) in group V. Only 23 of the 43 hips of Group 2 had preoperative arthrographs; there were 14 (60.87%) in group III, 8 (34.78%) in group IV, and 1 (4.35%) in group V. The preoperative Wiberg's Center-Edge (CE) angle of Group 2 (19.4 degrees) was significantly greater than that of Group 1 (16.7 degrees). The percentage difference (A%) between immediate postoperative and preoperative CE angle was significantly greater in Group 2. The delta% between final and immediate postoperative CE angle was significantly greater in Group 1, and within Group 1 it was significantly greater at age 4 years to 6 years. The A% between final and preoperative CE angle was statistically the same in both Group I and Group 2. The distribution of good, fair and poor Mose ratings did not differ in Group 1 and Group 2, but there was a tendency of better results after Augmented Acetabuloplasty in children older than 6 years. Younger patients of Group 1 (4-6 years) ended up with good results at a significantly higher frequency than the older ones. Group 1 children with preoperative Laredo III arthrography had good results in a significantly greater number of cases, as compared with Laredo grade IV. The delta% between final and immediate postoperative CE angle was greater in those hips with good Mose rating.

Acetabular augmentation using a glass-ceramic block: 3 patients followed 3-4 years

We have developed a block of glass-ceramic to augment the dysplastic acetabulum. 3 patients with acetabular dysplasia underwent implantation of a block of glass-ceramic on the lateral surface of the ilium just above the hip joint. The patients did not require immobilization and returned to their daily lives, walking without a cane 4 weeks after the operation. The mean Harris hip score was 47 points preoperatively and 94 points 3 years postoperatively.

Periosteal augmentation of the acetabulum

The periosteum in children and especially infants has significant osteogenic potential. To determine the efficacy of periosteal flaps to assist in improving acetabular coverage in children with acetabular dysplasia, a series of experiments were designed using young rabbits. Three groups of five rabbits each had periosteal flaps fashioned and brought down from the anterolateral aspect of the innominate bone superior to the acetabulum and sutured to the capsule of the hip. The study was designed to examine the effects of the periosteal cambium layer in the formation of new bone to augment the acetabulum and to determine the effects of a periosteal flap plus cancellous bone graft. A control group of five rabbits underwent a sham operation of an open arthrotomy of the hip. Radiographic and histologic examination at 12 weeks revealed augmentation of the acetabulum with periosteal flaps that resulted in an average improvement of the acetabular index of 3.5 degrees and 6.6 degrees, without and with bone graft, respectively. New bone formation from the rim of the acetabulum averaged 3.9 mm with periosteal flaps alone and 4.6 mm with bone graft added. Periosteal augmentation of the acetabulum in conjunction with established procedures for augmenting acetabular coverage would appear to be a useful procedure for improving coverage of the femoral head in children with acetabular dysplasia.

Surgical correction of "functional retroversion" and "functional coxa vara" in late Legg-Calvé-Perthes disease and epiphyseal dysplasia: correction of deformity defined by new imaging modalities

We studied six patients with severe femoral head deformity treated surgically by valgus-flexion-internal-rotation femoral osteotomy plus simultaneous acetabuloplasty based on the concept of "functional retroversion" and "functional coxa vara" of the deformed femoral head in late severe Legg-Calvé-Perthes disease and epiphyseal dysplasia. The combined procedure achieves the following: (i) corrects the "functional coxa vara" and hinge abduction (valgus osteotomy); (ii) establishes a more normal articulation between the posteromedial portion of the true femoral head and the acetabulum, while moving the anterolateral protruding portion of the femoral head away from the anterolateral acetabular margin (valgus-flexion osteotomy); (iii) corrects external-rotation deformity of the distal limb (internal-rotation osteotomy); (iv) improves joint congruity and anterolateral femoral-head coverage in hips with associated acetabular dysplasia (acetabuloplasty).

Glass-ceramic implant in acetabular bone defect: an experimental study

Extensive acetabular defects produced surgically in 25 dogs were repaired using A-W glass-ceramic blocks. No dislocation of the femoral head, and no displacement or breakdown of the blocks was seen 1 year after surgery. All dogs were able to run normally shortly after surgery, except for one that limped for a short time. The failure load between the blocks and the bone had increased markedly 2 months after implantation. The failure load/unit area was 33.2 kgw/cm 2 1 year after implantation. We conclude that glass-ceramic supplementation of the acetabulum is successful experimentally, and that this may be a promising method for repair of large acetabular bone defects.

Acetabuloplasty for congenital dislocation of the hip in children

A modified acetabuloplasty, which has been employed at our hospital since 1977, is described for the treatment of congenital dislocation of the hip in children. The procedure has been performed on a total of 74 hips in 61 children (average age 6.7 years), with satisfactory results obtained in 87.8% of hips. The technique, its indications, and pre- and postoperative management are detailed. The procedure possesses the advantages of both the shelf and Pemberton procedures and has proved to be an effective operation for older children with poor acetabular development. Our results show that, when performed correctly, this procedure is simple, safe, and effective.

Functional treatment of congenital dislocation of the hip

A prerequisite for the development of congenital dislocation of the hip is ligamentous laxity of the hip-joint, which is demonstrable shortly after birth when the hip can be easily dislocated and reduced. This situation is described as dislocatable hip. Ligamentous laxity naturally tends to disappear, and 90% of all dislocatable hips in fact stabilize spontaneously. No dislocation develops unless an exogenous factor is involved. In infants born in breech presentation the hyperextension of the knees with the resulting increased tension in the hamstrings plays a role. During or shortly after birth, the deflexion of the hip-joint causes an increased tension in the relatively shortened iliopsoas muscle, as a result of which the hip can be dislocated in postero-superior direction. By the time the infant is two months old secondary changes (more specifically restricted abduction) become more pronounced. It may therefore be stated that contracture of the iliopsoas muscle is one of the causes, and restricted abduction a consequence of congenital dislocation of the hip. The degree of dislocation is determined by a balance between the degree of ligamentous laxity and the influence of exogenous factors. When the infant starts to stand and walk, its body weight also begins to function as a deforming exogenous factor. When dislocatable hips are not treated immediately after birth, the frequency of congenital dislocation of the hip at the age of three months amounts to 1-2 per 1000 neonates. The male:female ratio is 1:4. The secondary changes in the osseous structures of the hip-joint should always be studied three-dimensionally. Apart from conventional antero-posterior pelvic roentgenograms, CT-scans can enhance spatial insight. The secondary changes manifest themselves in an enlarged neck-shaft angle, increased femoral anteversion, an increased inclination of the acetabulum and possibly also in diminished acetabular anteversion. In view of the high radiation load involved, examination by CT-scan is not yet a routine procedure in congenital hip dislocation. Radiological examination is usually confined to an antero-posterior pelvic roentgenogram on which the acetabular angle, the neck-shaft angle and the CE-angle can be measured. These are all values projected in a frontal plane. To determine the real values the degree of acetabular and femoral torsion has to be known. With the aid of the CT-scan the torsion of the acetabulum and of the femoral neck as well as their summation - the instability index - can be measured without difficulty.(ABSTRACT TRUNCATED AT 400 WORDS)

Treatment of hip dislocation after walking age

Between 1979 and 1981, 35 patients were treated at our institution. All patients were more than 18 months of age and 50 congenitally dislocated hips were treated. The average age at operation was 7 years and 3 months. Whereas children under the age of 6 were typically operated upon by open reduction and Salter, Pemberton, or Dega osteotomy partly combined with femoral osteotomy, in the group of the patients older than 6 years with high iliac hip dislocations, a method was used to avoid femoral shortening. By means of the Wagner distractor the dislocated hips were brought opposite to the acetabulum. This procedure was followed by femoral osteotomy and in most cases Chiari pelvic osteotomy. Despite a number of complications the results turned out better than expected. Compared with the preoperative X-ray classifications (Severin) the postoperative result was excellent in 10 cases, good in 20, fair in 15, and poor in 1 case.