The June 2024 Children’s orthopaedics Roundup³⁶⁰ looks at: Proximal femoral unicameral bone cysts: is ESIN the answer?; Hybrid-mesh casts in the conservative management of paediatric supracondylar humeral fractures: a randomized controlled trial; Rate and risk factors for contralateral slippage in adolescents treated for slipped capital femoral epiphysis; CRP predicts the need to escalate care after initial debridement for musculoskeletal infection; Genu valgum in paediatric patients presenting with patellofemoral instability; Nusinersen therapy changed the natural course of spinal muscular atrophy type 1: what about spine and hip?; The necessity of ulnar nerve exploration and translocation in open reduction of medial humeral epicondyle fractures in children.

Aims

The sacroiliac joint (SIJ) is the only mechanical connection between the axial skeleton and lower limbs. Following iliosacral resection, there is debate on whether reconstruction of the joint is necessary. There is a paucity of data comparing the outcomes of patients undergoing reconstruction and those who are not formally reconstructed.

Aims

Reimers migration percentage (MP) is a key measure to inform decision-making around the management of hip displacement in cerebral palsy (CP). The aim of this study is to assess validity and inter- and intra-rater reliability of a novel method of measuring MP using a smart phone app (HipScreen (HS) app).

The development of spinal deformity in children with underlying neurodisability can affect their ability to function and impact on their quality of life, as well as compromise provision of nursing care. Patients with neuromuscular spinal deformity are among the most challenging due to the number and complexity of medical comorbidities that increase the risk for severe intraoperative or postoperative complications. A multidisciplinary approach is mandatory at every stage to ensure that all nonoperative measures have been applied, and that the treatment goals have been clearly defined and agreed with the family. This will involve input from multiple specialities, including allied healthcare professionals, such as physiotherapists and wheelchair services. Surgery should be considered when there is significant impact on the patients’ quality of life, which is usually due to poor sitting balance, back or costo-pelvic pain, respiratory complications, or problems with self-care and feeding. Meticulous preoperative assessment is required, along with careful consideration of the nature of the deformity and the problems that it is causing. Surgery can achieve good curve correction and results in high levels of satisfaction from the patients and their caregivers. Modern modular posterior instrumentation systems allow an effective deformity correction. However, the risks of surgery remain high, and involvement of the family at all stages of decision-making is required in order to balance the risks and anticipated gains of the procedure, and to select those patients who can mostly benefit from spinal correction.

Aims

The diagnosis of developmental dysplasia of the hip (DDH) is challenging owing to extensive variation in paediatric pelvic anatomy. Artificial intelligence (AI) may represent an effective diagnostic tool for DDH. Here, we aimed to develop an anteroposterior pelvic radiograph deep learning system for diagnosing DDH in children and analyze the feasibility of its application.

Aims. Our retrospective analysis reports the outcome of patients operated for slipped capital femoral epiphysis using the modified Dunn procedure. Results, complications, and the need for revision surgery are compared with the recent literature. Methods. We retrospectively evaluated 17 patients (18 hips) who underwent the modified Dunn procedure for the treatment of slipped capital femoral epiphysis. Outcome measurement included standardized scores. Clinical assessment included ambulation, leg length discrepancy, and hip mobility. Radiographically, the quality of epiphyseal reduction was evaluated using the Southwick and Alpha-angles. Avascular necrosis, heterotopic ossifications, and osteoarthritis were documented at follow-up. Results. At a mean follow-up of more than nine years, the mean modified Harris Hip score was 88.7 points, the Hip Disability and Osteoarthritis Outcome Score (HOOS) 87.4 , the Merle d’Aubigné Score 16.5 points, and the UCLA Activity Score 8.4. One patient developed a partial avascular necrosis of the femoral head, and one patient already had an avascular necrosis at the time of delayed diagnosis. Two hips developed osteoarthritic signs at 14 and 16 years after the index operation. Six patients needed a total of nine revision surgeries. One operation was needed for postoperative hip subluxation, one for secondary displacement and implant failure, two for late femoroacetabular impingement, one for femoroacetabular impingement of the opposite hip, and four for implant removal. Conclusion. Our series shows good results and is comparable to previous published studies. The modified Dunn procedure allows the anatomic repositioning of the slipped epiphysis. Long-term results with subjective and objective hip function are superior, avascular necrosis and development of osteoarthritis inferior to other reported treatment modalities. Nevertheless, the procedure is technically demanding and revision surgery for secondary femoroacetabular impingement and implant removal are frequent. Cite this article: 2020;1-4:80–87

Aims

The aim of this study was to evaluate the prosthesis characteristics and associated conditions that may modify the survival of total femoral endoprosthetic replacements (TFEPR).

The August 2015 Children’s orthopaedics Roundup³⁶⁰ looks at: Learning the Pavlik; MRI and patellar instability; Cerebral palsy and hip dysplasia; ‘Pick your poison’: elastic nailing under the spotlight; Club feet and surgery; Donor site morbidity in vascularised fibular grafting; Cartilage biochemistry with hip dysplasia; SUFE and hip decompression: a good option?

In this in vitro study of the hip joint we examined which soft tissues act as primary and secondary passive rotational restraints when the hip joint is functionally loaded. A total of nine cadaveric left hips were mounted in a testing rig that allowed the application of forces, torques and rotations in all six degrees of freedom. The hip was rotated throughout a complete range of movement (ROM) and the contributions of the iliofemoral (medial and lateral arms), pubofemoral and ischiofemoral ligaments and the ligamentum teres to rotational restraint was determined by resecting a ligament and measuring the reduced torque required to achieve the same angular position as before resection. The contribution from the acetabular labrum was also measured. Each of the capsular ligaments acted as the primary hip rotation restraint somewhere within the complete ROM, and the ligamentum teres acted as a secondary restraint in high flexion, adduction and external rotation. The iliofemoral lateral arm and the ischiofemoral ligaments were primary restraints in two-thirds of the positions tested. Appreciation of the importance of these structures in preventing excessive hip rotation and subsequent impingement/instability may be relevant for surgeons undertaking both hip joint preserving surgery and hip arthroplasty.

Cite this article: Bone Joint J 2015; 97-B:484–91.

The aim of this study was to evaluate the functional and oncological outcome of extracorporeally irradiated autografts used to reconstruct the pelvis after a P1/2 internal hemipelvectomy.

The study included 18 patients with a primary malignant bone tumour of the pelvis. There were 13 males and five females with a mean age of 24.8 years (8 to 62). Of these, seven had an osteogenic sarcoma, six a Ewing’s sarcoma, and five a chondrosarcoma. At a mean follow-up of 51.6 months (4 to 185), nine patients had died with metastatic disease while nine were free from disease. Local recurrence occurred in three patients all of whom eventually died of their disease. Deep infection occurred in three patients and required removal of their graft in two while the third underwent a hindquarter amputation for extensive flap necrosis.

The mean Musculoskeletal Tumor Society functional score of the 16 patients who could be followed-up for at least 12 months was 77% (50 to 90). Those 15 patients who completed the Toronto Extremity Salvage Score questionnaire had a mean score of 71% (53 to 85).

Extracorporeal irradiation and re-implantation of bone is a valid method of reconstruction after an internal hemipelvectomy. It has an acceptable morbidity and a functional outcome that compares favourably with other available reconstructive techniques.

Cite this article: Bone Joint J 2014;96-B:1404–10

The aim of this study was to investigate the incidence of dysplasia in the ‘normal’ contralateral hip in patients with unilateral developmental dislocation of the hip (DDH) and to evaluate the long-term prognosis of such hips. A total of 48 patients (40 girls and eight boys) were treated for late-detected unilateral DDH between 1958 and 1962. After preliminary skin traction, closed reduction was achieved at a mean age of 17.8 months (4 to 65) in all except one patient who needed open reduction. In 25 patients early derotation femoral osteotomy of the contralateral hip had been undertaken within three years of reduction, and later surgery in ten patients. Radiographs taken during childhood and adulthood were reviewed. The mean age of the patients was 50.9 years (43 to 55) at the time of the latest radiological review.

In all, eight patients (17%) developed dysplasia of the contralateral hip, defined as a centre-edge (CE) angle < 20° during childhood or at skeletal maturity. Six of these patients underwent surgery to improve cover of the femoral head; the dysplasia improved in two after varus femoral osteotomy and in two after an acetabular shelf operation. During long-term follow-up the dysplasia deteriorated to subluxation in two patients (CE angles 4° and 5°, respectively) who both developed osteoarthritis (OA), and one of these underwent total hip replacement at the age of 49 years.

In conclusion, the long-term prognosis for the contralateral hip was relatively good, as OA occurred in only two hips (4%) at a mean follow-up of 50 years. Regular review of the ‘normal’ side is indicated, and corrective surgery should be undertaken in those who develop subluxation.

Cite this article: Bone Joint J 2014; 96-B:1161–6.

The June 2013 Children’s orthopaedics Roundup³⁶⁰ looks at: whether reaching a diagnosis is more difficult than previously thought; adolescent and paediatric DDH; the A-frame orthosis and Legg-Calvé-Perthes’ disease; failure of hip surgery in patients with cerebral palsy; adolescent rotator cuff injuries; paediatric peripheral nerve injuries; predicting residual deformity following Ponseti treatment; and the Dunn procedure.

We reviewed the long-term radiological outcome, complications and revision operations in 19 children with quadriplegic cerebral palsy and hip dysplasia who underwent combined peri-iliac osteotomy and femoral varus derotation osteotomy. They had a mean age of 7.5 years (1.6 to 10.9) and comprised 22 hip dislocations and subluxations. We also studied the outcome for the contralateral hip. At a mean follow-up of 11.7 years (10 to 15.1) the Melbourne cerebral palsy (CP) hip classification was grade 2 in 16 hips, grade 3 in five, and grade 5 in one. There were five complications seen in four hips (21%, four patients), including one dislocation, one subluxation, one coxa vara with adduction deformity, one subtrochanteric fracture and one infection. A recurrent soft-tissue contracture occurred in five hips and ten required revision surgery. In pre-adolescent children with quadriplegic cerebral palsy good long-term outcomes can be achieved after reconstruction of the hip; regular follow-up is required. Cite this article: Bone Joint J 2013;95-B:259–65

It is probable that both genetic and environmental factors play some part in the aetiology of most cases of degenerative hip disease. Geneticists have identified some single gene disorders of the hip, but have had difficulty in identifying the genetics of many of the common causes of degenerative hip disease. The heterogeneity of the phenotypes studied is part of the problem. A detailed classification of phenotypes is proposed. This study is based on careful documentation of 2003 consecutive total hip replacements performed by a single surgeon between 1972 and 2000. The concept that developmental problems may initiate degenerative hip disease is supported. The influences of gender, age and body mass index are outlined. Biomechanical explanations for some of the radiological appearances encountered are suggested. The body weight lever, which is larger than the abductor lever, causes the abductor power to be more important than body weight. The possibility that a deficiency in joint lubrication is a cause of degenerative hip disease is discussed. Identifying the phenotypes may help geneticists to identify genes responsible for degenerative hip disease, and eventually lead to a definitive classification.

Peripheral nerve injury is an uncommon but serious complication of hip surgery that can adversely affect the outcome. Several studies have described the use of electromyography and intra-operative sensory evoked potentials for early warning of nerve injury. We assessed the results of multimodal intra-operative monitoring during complex hip surgery. We retrospectively analysed data collected between 2001 and 2010 from 69 patients who underwent complex hip surgery by a single surgeon using multimodal intra-operative monitoring from a total pool of 7894 patients who underwent hip surgery during this period. In 24 (35%) procedures the surgeon was alerted to a possible lesion to the sciatic and/or femoral nerve. Alerts were observed most frequently during peri-acetabular osteotomy. The surgeon adapted his approach based on interpretation of the neurophysiological changes. From 69 monitored surgical procedures, there was only one true positive case of post-operative nerve injury. There were no false positives or false negatives, and the remaining 68 cases were all true negative. The sensitivity for predicting post-operative nerve injury was 100% and the specificity 100%. We conclude that it is possible and appropriate to use this method during complex hip surgery and it is effective for alerting the surgeon to the possibility of nerve injury.

Dislocation is a common and well-studied complication after total hip replacement. However, subluxation, which we define as a clinically recognised episode of incomplete movement of the femoral head outside the acetabulum with spontaneous reduction, has not been studied previously. Out of a total of 2521 hip replacements performed over 12 years by one surgeon, 30 patients experienced subluxations which occurred in 31 arthroplasties. Data were collected prospectively with a minimum follow-up of two years. Subluxation occurred significantly more frequently after revision than after primary hip replacement, and resolved in 19 of 31 cases (61.3%). In six of the 31 hips (19.4%) the patient subsequently dislocated the affected hip, and in six hips (19.4%) intermittent subluxation continued. Four patients had a revision operation for instability, three for recurrent dislocation and one for recurrent subluxation. Clinical and radiological comparisons with a matched group of stable total hips showed no correlation with demographic or radiological parameters.

Patients with subluxing hips reported significantly more concern that their hip would dislocate, more often changed their behaviour to prevent instability and had lower postoperative Harris hip scores than patients with stable replacements.

We have tested the reliability of a recently reported classification system of hip morphology in adolescents with cerebral palsy in whom the triradiate cartilage was closed. The classification is a six-grade ordinal scale, based on the measurement of the migration percentage and an assessment of Shenton’s arch, deformity of the femoral head, acetabular deformity and pelvic obliquity.

Four paediatric orthopaedic surgeons and four physiotherapists received training in the use of the classification which they applied to the assessment of 42 hip radiographs, read on two separate occasions. The inter- and intra-observer reliability was assessed using the intraclass correlation coefficient and found to be excellent, with it ranging from 0.88 to 0.94. The classification in our study was shown to be valid (based on migration percentage), and reliable. As a result we believe that it can now be used in studies describing the natural history of hip displacement in cerebral palsy, in outcome studies and in communication between clinicians.

Heterotopic ossification (HO) of the hip after injury to the central nervous system can lead to joint ankylosis. Surgery is usually delayed to avoid recurrence, even if the functional status is affected. We report a consecutive series of patients with HO of the hip after injury to the central nervous system who required surgery in a single, specialised tertiary referral unit. As was usual practice, they all underwent CT to determine the location of the HO and to evaluate the density of the femoral head and articular surface. The outcome of surgery was correlated with the pre-, peri- and post-operative findings.

In all, 183 hips (143 patients) were included of which 70 were ankylosed. A total of 25 peri-operative fractures of the femoral neck occurred, all of which arose in patients with ankylosed hips and were associated with intra-articular lesions in 18 and severe osteopenia of the femoral head in seven. All the intra-articular lesions were predicted by CT and strongly associated with post-operative complications.

The loss of the range of movement before ankylosis is a more important factor than the maturity of the HO in deciding the timing of surgery. Early surgical intervention minimises the development of intra-articular pathology, osteoporosis and the resultant complications without increasing the risk of recurrence of HO.

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.

In patients with severe quadriplegic cerebral palsy and painful hip dislocation proximal femoral resection arthroplasty can reduce pain, but the risk of heterotopic ossification is significant. We present a surgical technique of autologous capping of the femoral stump in order to reduce this risk, using the resected femoral head as the graft.

A retrospective study of 31 patients (43 hips) who had undergone proximal femoral resection arthroplasty with (29 hips) and without autologous capping (14 hips) was undertaken. Heterotopic ossification was less frequent in patients with autologous capping, and a more predictable pattern of bony overgrowth was found.

For a selected group of non-ambulatory patients with long-standing painful dislocation of the hip, we recommend femoral resection arthroplasty over more complicated reconstructive operations. The risk of heterotopic ossification, which is a major disadvantage of this operation, is reduced by autologous capping.

We present a retrospective review of a single-surgeon series of 30 consecutive lengthenings in 27 patients with congenital short femur using the Ilizarov technique performed between 1994 and 2005.

The mean increase in length was 5.8 cm/18.65% (3.3 to 10.4, 9.7% to 48.8%), with a mean time in the frame of 223 days (75 to 363). By changing from a distal to a proximal osteotomy for lengthening, the mean range of knee movement was significantly increased from 98.1° to 124.2° (p = 0.041) and there was a trend towards a reduced requirement for quadricepsplasty, although this was not statistically significant (p = 0.07). The overall incidence of regenerate deformation or fracture requiring open reduction and internal fixation was similar in the distal and proximal osteotomy groups (56.7% and 53.8%, respectively). However, in the proximal osteotomy group, pre-placement of a Rush nail reduced this rate from 100% without a nail to 0% with a nail (p < 0.001). When comparing a distal osteotomy with a proximal one over a Rush nail for lengthening, there was a significant decrease in fracture rate from 58.8% to 0% (p = 0.043).

We recommend that in this group of patients lengthening of the femur with an Ilizarov construct be carried out through a proximal osteotomy over a Rush nail. Lengthening should also be limited to a maximum of 6 cm during one treatment, or 20% of the original length of the femur, in order to reduce the risk of complications.

The outcome of one-stage bilateral open reduction through a medial approach for the treatment of developmental dysplasia of the hip in children under 18 months was studied in 23 children, 18 girls and five boys. Their mean age at operation was 10.1 months (6 to 17) and the mean follow-up was 5.4 years (3 to 8).

Acceptable clinical and radiological results were achieved in 44 (95.7%) and 43 (93.5%) of 46 hips, respectively. Excellent results were significantly evident in patients younger than 12 months, those who did not require acetabuloplasty, those whose ossific nucleus had appeared, and in those who did not develop avascular necrosis.

One-stage bilateral medial open reduction avoids the need for separate procedures on the hips and has the advantages of accelerated management and shorter immobilisation and rehabilitation than staged operations.

There is much debate about the nature and extent of deformities in the proximal femur in children with cerebral palsy. Most authorities accept that increased femoral anteversion is common, but its incidence, severity and clinical significance are less clear. Coxa valga is more controversial and many authorities state that it is a radiological artefact rather than a true deformity.

We measured femoral anteversion clinically and the neck-shaft angle radiologically in 292 children with cerebral palsy. This represented 78% of a large, population-based cohort of children with cerebral palsy which included all motor types, topographical distributions and functional levels as determined by the gross motor function classification system.

The mean femoral neck anteversion was 36.5° (11° to 67.5°) and the mean neck-shaft angle 147.5° (130° to 178°). These were both increased compared with values in normally developing children. The mean femoral neck anteversion was 30.4° (11° to 50°) at gross motor function classification system level I, 35.5° (8° to 65°) at level II and then plateaued at approximately 40.0° (25° to 67.5°) at levels III, IV and V. The mean neck-shaft angle increased in a step-wise manner from 135.9° (130° to 145°) at gross motor function classification system level I to 163.0° (151° to 178°) at level V. The migration percentage increased in a similar pattern and was closely related to femoral deformity.

Based on these findings we believe that displacement of the hip in patients with cerebral palsy can be explained mainly by the abnormal shape of the proximal femur, as a result of delayed walking, limited walking or inability to walk. This has clinical implications for the management of hip displacement in children with cerebral palsy.

Our aim was to evaluate the efficacy of a two-level reconstruction technique using subchondral miniscrews for the stabilisation of comminuted posterior-wall marginal acetabular fragments before applying lag screws and a buttress plate to the main overlying posterior fragment. Between 1995 and 2003, 29 consecutive patients with acute comminuted displaced posterior-wall fractures of the acetabulum were treated operatively using this technique.

The quality of reduction measured from three standard plain radiographs was graded as anatomical in all 29 hips. The clinical outcome at a mean follow-up of 35 months (24 to 90) was considered to be excellent in five patients (17%), very good in 16 (55%), good in six (21%) and poor in two (7%). The use of the two-level reconstruction technique appears to provide stable fixation and is associated with favourable results in terms of the incidence of post-traumatic osteoarthritis and the clinical outcome. However, poor results may occur in patients over the age of 55 years.

In order to treat painful subluxation or dislocation secondary to cerebral palsy, 11 patients (12 hips) underwent combined femoral and Chiari pelvic osteotomies with additional soft-tissue releases at a mean age of 14.1 years (9.1 to 17.8). Relief of pain, improvement in movement of the hip, and in sitting posture, and ease of perineal care were recorded in all, and were maintained at a mean follow-up of 13.1 years (8 to 17.5). The improvement in general mobility was marginal, but those who were able to walk benefited the most.

The radiological measurements made before operation were modified afterwards to use the lateral margin of the neoacetabulum produced by the pelvic osteotomy. The radiological migration index improved from a mean of 80.6% (61% to 100%) to 13.7% (0% to 33%) (p < 0.0001). The mean changes in centre edge angle and Sharp’s angle were 72° (56° to 87°; p < 0.0001) and 12.3° (9° to 15.6°; p < 0.0001), respectively. Radiological evidence of progressive arthritic change was seen in one hip, in which only a partial reduction had been achieved, and there was early narrowing of the joint space in another. Painless heterotopic ossification was observed in one patient with athetoid quadriplegia. In seven hips the lateral Kawamura approach, elevating the greater trochanter, provided exposure for both osteotomies and allowed the construction of a dome-shaped iliac osteotomy, while protecting the sciatic nerve.

Difficulties posed in managing developmental dysplasia of the hip diagnosed late include a high-placed femoral head, contracted soft tissues and a dysplastic acetabulum. A combination of open reduction with femoral shortening of untreated congenital dislocations is a well-established practice. Femoral shortening prevents excessive pressure on the located femoral head which can cause avascular necrosis. Instability due to a coexisting dysplastic shallow acetabulum is common, and so a pelvic osteotomy is performed to achieve a stable and concentric hip reduction. We retrospectively reviewed 15 patients (18 hips) presenting with developmental dysplasia of the hip aged four years and above who were treated by a one-stage combined procedure performed by the senior author. The mean age at operation was five years and nine months (4 years to 11 years). The mean follow-up was six years ten months (2 years and 8 months to 8 years and 8 months). All patients were followed up clinically and radiologically in accordance with McKay’s criteria and the modified Severin classification. According to the McKay criteria, 12 hips were rated excellent and six were good. All but one had a full range of movement. Eight had a limb-length discrepancy of about 1 cm. All were Trendelenburg negative. The modified Severin classification demonstrated four hips of grade IA, six of grade IB, and eight of grade II. One patient had avascular necrosis and one an early subluxation requiring revision.

One-stage correction of congenital dislocation of the hip in an older child is a safe and effective treatment with good results in the short to medium term.

A total of 47 non-walking patients (52 hips) with severe cerebral palsy and with a mean age of 14 years, (9 to 27) underwent a Dega-type pelvic osteotomy after closure of the triradiate cartilage, together with a derotation varus-shortening femoral osteotomy and soft-tissue correction for hip displacement which caused pain and/or difficulties in sitting. The mean follow-up was 48 months (12 to 153). The migration percentage improved from a pre-operative mean of 70% (26% to 100%) to 10% (0% to 100%) post-operatively. In five hips the post-operative migration percentage was greater than 25%, which was associated with continuing pain in two patients. Three patients had persistent hip pain and a migration percentage less than 25%. In five hips a fracture through the acetabulum occurred, and in another there was avascular necrosis of the superior acetabular segment, but these had no adverse effect on functional outcome. We conclude that it is possible to perform a satisfactory pelvic osteotomy of this type in these patients after the triradiate cartilage has been closed.

Subluxation of the hip is common in patients with intermediate spinal muscular atrophy. This retrospective study aimed to investigate the influence of surgery on pain and function, as well as the natural history of subluxed hips which were treated conservatively. Thirty patients were assessed clinically and radiologically. Of the nine who underwent surgery only one reported satisfaction and four had recurrent subluxation. Of the 21 patients who had no surgery, 18 had subluxation at the latest follow-up, but only one reported pain in the hip. We conclude that surgery for subluxation of the hip in these patients is not justified.

Using radiography and computer tomography (CT) we studied the morphology of 83 hips in 69 Caucasian adults with osteoarthritis secondary to developmental dysplasia of the hip (DDH). A previously published series of 310 hips with primary osteoarthritis was used as a control group. According to the Crowe classification, 33 of the dysplastic hips were graded as class I, 27 as class II and 23 as class III or class IV.

The intramedullary femoral canal had reduced mediolateral and anteroposterior dimensions in all groups compared with the control group. Only in Crowe class II hips was the femoral neck-shaft angle increased. The proximal femur had more anteversion in all the developmental dysplasia of the hip groups, ranging from 2° to 80°. Templated measurement of acetabular dimensions for plain radiography closely matched measurements taken by CT.

The results of our study confirm the observations previously confined to the Japanese population.

Between 1980 and 1988, displacement bone-marrow transplantation was performed on 25 children with Hurler's syndrome (type-1 mucopolysaccharidosis). We describe the musculoskeletal development of 11 of the 12 surviving children and the orthopaedic procedures undertaken to treat progressive thoracolumbar kyphosis, hip subluxation and carpal tunnel syndrome. We found abnormal bone modelling, focal failures of ossification and an avascular disorder of the femoral head in every patient and offer an explanation for these phenomena. Increasing valgus deformity of the knees and progressive generalised myopathy caused loss of mobility as the children entered adolescence. The benefit of bone-marrow transplantation as a treatment for the skeletal disorders of Hurler's syndrome is limited by the poor penetration of the musculoskeletal tissues by the enzyme derived from the leucocytes

Tectoplasty is a new acetabuloplasty which aims to provide an extra-articular weight-bearing surface in cases of dysplastic acetabulum, hip subluxation or dislocation with a false acetabulum. The lateral wall of the iliac bone at the lateral edge of the affected acetabulum is raised as a proximally-based flap and massive bone grafts are inserted to provide a congruous, non-absorbable roof for the capsule and femoral head. An advantage is that the weight-bearing surface can be formed away from the original acetabulum, wherever the dislocated or subluxated femoral head may lie. Of 34 hips with congenital dislocation or severe subluxation treated by this method, 27 were evaluated after an average follow-up of 12 years. At review the patients averaged 35 years of age and satisfactory results with good relief of pain had been obtained in 78%. The results were unsatisfactory when degenerative changes had already developed before operation. Tectoplasty is indicated for pain due to congenital subluxation or dislocation of the hip under the age of thirty, in the absence of advanced osteoarthritis

Perthes' disease involving the whole of the femoral head in 36 children was treated by innominate osteotomy. Radiographs of all cases were reviewed to see the effect of the osteotomy on the shape, the degree of acetabular cover and any subluxation of the diseased femoral head. All femoral heads which were circular before operation remained so, and over half of the previously deformed heads became circular after the osteotomy. The improved acetabular cover provided by the osteotomy resulted in a CE angle of 25 degrees or more in 92% of hips. Possible subluxation of the femoral head was studied by inspecting Shenton's line. If this was intact before operation it remained so; of the 14 which were broken before operation, 11 were restored to normal after osteotomy. We conclude that innominate osteotomy is a worthwhile procedure for Perthes' disease involving the whole of the femoral head

A case of early closure of the triradiate cartilage, probably secondary to neonatal septic arthritis of the right hip, is reported. Tomograms of the hip showed the triradiate cartilage closed posteriorly, with the anterior portion still open. These findings were confirmed at operation. An arthrogram and a CT scan of the right hip showed subluxation of the femoral head. This unique complication, after an episode of septic arthritis of the hip, has not before been reported in the literature

Based on the constancy with which the limbus is inverted into the joint in a typical congenital dislocation of the hip, a hypothesis is presented which suggests that the sequence of events leading to established dislocation is: 1) lateral rotation aided and abetted by anteversion; 2) extension of the hips causing subluxation; 3) dislocation and inversion of the limbus; 4) secondary changes in the upper end of the femur, pelvis and acetabulum which will also develop if the deformity does not progress beyond a subluxation. A pen picture is drawn showing how anteversion is either moulded away during growth to produce a normal hip, or persists with or without dislocation. The fate of the persistently inverted limbus is discussed and a line of treatment based on these findings is briefly considered