In late presenting developmental Dysplasia of hip there is controversy as to the most appropriate method of treatment. The purpose of study was to determine the outcome following the non-operative and operative treatment for late presenting developmental dysplasia of hip. Retrospective study. Inclusion criteria – (1) Unilateral DH (2) Diagnosed 6 months or more after birth (3) Minimum follow up of 2 years after treatment. 41 patients matched the inclusion criteria. 32 patients attended the follow-up clinic. Patients were divided into non-operative and operative group. Outcome instruments used include activities scale for kids (ASK), physical component of SF36 v2, centre edge angle and severin classification system, all validated scoring systems. 32 patients with mean follow-up of 7 (2–12_ years. Mean age at the time of follow-up was 9 (range 2.7 – 15) years. In our series, 15 patients received non-operative and 17 patients received operative treatment. On ASK, conservatively treated hips scored 72% and surgically treated hips scored 69%. (P-Value = > 0.05). On SF36 v2, mean value of physical function score (PFS) for both non-operative and operative group were 57.58 respectively (P Value > 0.05). Centre edge angle (CEA) of non-operative and operative group were compared with their contra-lateral normal sides (P Value > 0.05). According to Severin classification system, 7 hips were grade I, 8 were grade II in the non operative group and in operative group, 10 were grade II, 5 were grade III and 2 were grade IV. There were no major complications and only one (3%) hip developed avascular necrosis of hip. On a medium term follow-up, despite some radiological abnormalities, most of the patients achieved good functional results following both non-operative treatments for late presenting DDH. There was no statistically significant difference in the development of hips either treated conservatively or surgically. Long term follow up studies are required in order to establish the true outcome of late presenting DDH treated either conservatively or surgically

This study shows the efficacy of The Pavlik harness for the treatment of Development Dysplasia of Hip using ultrasonographic monitoring. Between March 1995 and February 2000 we treated 149 dysplastic hips in 117 babies. According to the Graf’s classification 90 were dysplastic type IIB, IIC,IID hips; 59 were dislocated Type IIIA, IIIB and IV hips. Babies were regularly monitored using ultrasound until the age of 26 weeks and radiographs there after for bony roof angle. The Pavlik harness was abandoned if there was persistent dislocation of hip at the end of 3 weeks of treatment. The average full time harness treatment was 12.2 ( range 6–20 ) weeks. The average follow up was 55 ( range 30–90 ) months. The harness failed to reduce 14 hips ( 9.5 % of total hips). These required arthrogram and closed or open reductions. Late presentation beyond 12 weeks and a higher grade on the Graf’s classification reduces the success rate of the pavlik harness treatment. Two cases continue to show a small femoral ossific nuclei at 30 months follow up. The hips treated successfully showed no significant difference in acetabular index from the normal values at follow up radiographs. We conclude that using our protocol, successful initial treatment of Developmental Dysplasia of Hip with the Pavlik harness appears to restore normal development of the hip. We continue to monitor patients by regular radiological surveillance up to 3 years in dysplastic hips and 5 years in unstable and dislocated hips

Aims

Despite the presence of screening programmes, infants continue to present with late developmental dysplasia of the hip (DDH), the impact of which is significant. The aim of this study was to assess infants with late presenting dislocation of the hip despite universal clinical neonatal and selective ultrasound screening.

The term developmental dysplasia of the hip (DDH) describes a spectrum of disorders that results in abnormal development of the hip joint. If not treated successfully in childhood, these patients may go on to develop hip symptoms and/or secondary osteoarthritis in adulthood. In this review we describe the altered anatomy encountered in adults with DDH along with the management options, and the challenges associated with hip arthroscopy, osteotomies and arthroplasty for the treatment of DDH in young adults.

Cite this article: Bone Joint J 2013;95-B:732–7.

Introduction: The distorted anatomy in Developmental Dysplasia of the Hip (DDH) makes a total hip arthroplasty (THA) a challenging procedure. The purpose of the current study is to report the midterm results after uncemented primary hip arthroplasty using S ROM prosthesis in a prospective series of patients with hip dysplasia.

Methods: We performed 22 uncemented total hip replacements using S ROM prosthesis in 21 (12 female and 9 male) patients with hip dysplasia. The means age at the time of hip surgery was 41.8 (22 to 64) years. The mean follow-up was 6.3 (3.8 to 9.6) years. In 9 (40.9%) patients the operative treatment of DDH was performed during the early childhood (femoral osteotomy in 6 and pelvic osteotomy in 3). All patients were evaluated clinically and radiologically. The femoral head displacement prior to THA surgery was classified according to Crowe at al. classification (4 hips were type1, 2 type2, 10 type3 and 6 type 4).

Results: The average Harris Hip Score improved from 29.48 to 72.76 (44 to 99) and the average Oxford hip score is 31.22 (12 to 47). The range of flexion is 60°–120° (average 83.23) and abduction is 10°–40°(average 22.94). None of the hips has dislocated. Radiolucent lines were noted around the femoral stem in one case. None of the cases have developed osteolysis around femoral prosthesis. In one patient (4.5%), revision hip surgery was done for aseptic loosening of cemented acetabular cup.

Discussion: The midterm results of total hip replacement in DDH using S ROM uncemented prosthesis are promising. We recommend this modular prosthesis for hip replacement in dysplastic hips.

Aim

The purpose of this study was to analyze the patellofemoral kinematics in neglected adult developmental dysplasia of the hip patients with patellofemoral symptoms and tried to clarify the affect of the severity of dislocation, the amount of limb length discrepancy, the deviation of mechanical axis and the changes in femoral anteversion on patellofemoral alignment.

Aims: This study shows the efþcacy of The Pavlik harness for the treatment of Development Dysplasia of hip (DDH) using ultrasonographic monitoring. Methods: Between 1995–2000 we treated 149 dysplastic hips in 117 babies. According to the Grafñs classiþcation 90 were dysplastic type IIB, IIC, IID hips; 59 were dislocated Type IIIA, IIIB and IV hips. Babies were regularly monitored using ultrasound unto 26 weeks and radiographs up to 5 years in dislocated hips for bony roof angle. Results: The average full time harness treatment was 12.2 (range 6–20) weeks, average follow up was 55 (range 30–90) months. The harness failed to reduce 14 hips (9.5% of total hips). Two cases continue to show a small femoral ossiþc nuclei at 30 months follow up. The hips showed no signiþcant difference in acetabular index from the normal values at follow up radiographs. Conclusions: We conclude that using this protocol, successful initial treatment of DDH with the Pavlik harness appears to restore normal development of the hip.

Developmental dysplasia of the hip (DDH) should be diagnosed as early as possible to optimise treatment. The current United Kingdom recommendations for the selective screening of DDH include a clinical examination at birth and at six weeks. In Northern Ireland babies continue to have an assessment by a health visitor at four months of age. As we continue to see late presentations of DDH, beyond one year of age, we hypothesised that a proportion had missed an opportunity for earlier diagnosis. We expect those who presented to our service with Tonnis grade III or IV hips and decreased abduction would have had clinical signs at their earlier assessments.

We performed a retrospective review of all patients born in Northern Ireland between 2008 and 2010 who were diagnosed with DDH after their first birthday. There were 75 856 live births during the study period of whom 645 children were treated for DDH (8.5 per 1000). The minimum follow-up of our cohort from birth, to detect late presentation, was four years and six months. Of these, 32 children (33 hips) were diagnosed after their first birthday (0.42 per 1000).

With optimum application of our selective screening programme 21 (65.6%) of these children had the potential for an earlier diagnosis, which would have reduced the incidence of late diagnosis to 0.14 per 1000. As we saw a peak in diagnosis between three and five months our findings support the continuation of the four month health visitor check. Our study adds further information to the debate regarding selective versus universal screening.

Cite this article: Bone Joint J 2015;97-B:1572–6.

There is no consensus regarding the optimum frequency of ultrasound for monitoring the response to Pavlik harness (PH) treatment in developmental dysplasia of hip (DDH). The purpose of our study was to determine if a limited-frequency hip ultrasound (USS) assessment in children undergoing PH treatment for DDH had an adverse effect on treatment outcomes when compared to traditional comprehensive ultrasound monitoring. This study was a single-center non-inferiority randomized controlled trial. Children aged less than six months of age with dislocated, dislocatable and stable dysplastic hips undergoing a standardized treatment program with a PH were randomized, once stability had been achieved, to our current standard USS monitoring protocol (every clinic visit) or to a limited-frequency ultrasound protocol (USS only until hip stability and then end of treatment). Groups were compared based on alpha angle at the end of treatment, acetabular indices (AI) and IHDI grade on follow up radiographs at one-year post harness and complication rates. The premise was that if there were no differences in these outcomes, either protocol could be deemed safe and effective. One hundred patients were recruited to the study; after exclusions, 42 patients completed the standard protocol (SP) and 36 completed the limited protocol (LP). There was no significant difference between the mean age between both groups at follow up x-ray (SP: 17.8 months; LP: 16.6 months; p=0.26). There was no difference between the groups in mean alpha angle at the end of treatment (SP: 69°; LP: 68.1°: p=0.25). There was no significant difference in the mean right AI at follow up (SP: 23.1°; LP: 22.0°; p=0.26), nor on the left (SP:23.3°; LP 22.8°; p=0.59). All hips in both groups were IHDI grade 1 at follow up. The only complication was one femoral nerve palsy in the SP group. In addition, the LP group underwent a 60% reduction in USS use once stable. We found that once dysplastic or dislocated hips were reduced and stable on USS, a limited- frequency ultrasound protocol was not associated with an inferior complication or radiographic outcome profile compared to a standardized PH treatment pathway. Our study supports reducing the frequency of ultrasound assessment during PH treatment of hip dysplasia. Minimizing the need for expensive, time-consuming and in-person health care interventions is critical to reducing health care costs, improving patient experience and assists the move to remote care. Removing the need for USS assessment at every PH check will expand care to centers where USS is not routinely available and will facilitate the establishment of virtual care clinics where clinical examination may be performed remotely

Incidence of Congenital talipes equino varus [CTEV] is 1 to 2 per 1000 birth, Out of all cases 20% cases are Non-idiopathic. The management of non-idiopathic CTEV, however, continues to be challenging due to Rigidity, Poor skin condition, Bony changes, Vascularity and Associated congenital abnormalities. In recent literature, short term results of Ponseti method for correction of non-idiopathic CTEV have been encouraging. As Ponseti method decreases the severity of deformity and hence decreases the need for extensive surgery. The aim of current study is to evaluate the results of Ponseti method in Non-idiopathic CTEV. Total 7 children below the age of one year with Non idiopathic clubfoot presented to us in the duration of 2013 to 2015 who were treated by us. The cases included are Streeters Dysplasia with congenital constriction rings 3, Arthrogryposis multiplex congenita with Developmental dysplasia of hip 2, Arthrogryposis multiple congenita spina Bifida 1, Pierre Robinson Syndrome with Ichthiosis 1. Initially all the patients treated with Ponseti casting technique and scoring was done using modified pirani scoring. At an average we could correct the foot from Pirani 7 to 2.5 with a relapse in 4 patients. 2 patients were treated again by Ponseti's method with success while treatment was discontinued in 2 feet. We recommended Ponseti's technique in Syndromic clubfoot as an non-surgical initial modality with good results given. The final outcome may depend more on the underlying condition than the CTEV

Revision total hip arthroplasty (THA) is a challenging scenario following complex primary THA for developmental dysplasia of hip (DDH). Our study envisages the long-term outcomes of revision DDH and the role of lateral structural support in socket fixation in these young patients who may require multiple revisions in their life-time. Hundred and eighteen consecutive cemented revision THAs with minimum follow up of 5 years following primary diagnosis of DDH operated between January 1974 and December 2012 were analysed for their clinical and radiological outcomes. The mean follow-up of 118 patients was 11.0 years (5.1–39.6 years). The Kaplan Mier survivorship at 11 years with end point as revision for any reason was 89.8% (CI 81.1–98.4). Of 118 revisions, 88 acetabular revisions were for aseptic loosening. Out of the acetabular revisions, 21 had pre-existing structural bone grafts from primary surgery, of which only 3 needed structural re-grafting during revision. Amongst the remaining 18 hips, the lateral support from the previous graft facilitated revision with no requirement of additional structural graft. Sixty-three hips did not have any form of grafting during primary operation. Amongst them, 35 had bone grafting in revision surgery (18 structural grafting). This study reports the largest number of revision THAs with primary diagnosis of DDH with the longest follow up. In our experience, the lateral support from the structural graft done in primary operation appears to have provided benefit in subsequent revision socket fixation

Background. Revision total hip arthroplasty (THA) is a challenging scenario following complex primary THA for developmental dysplasia of hip (DDH). This study envisages the long-term outcomes of revision DDH and the role of lateral structural support in socket fixation in these young patients who may require multiple revisions in their life-time. Materials and methods. Hundred and eighteen consecutive cemented revision THAs with minimum follow up of 5 years following primary diagnosis of DDH operated by a single unit between January 1974 and December 2012 were analysed for their clinical and radiological outcomes. Results. The mean follow-up of 118 patients was 11.0 years (5.1–39.6 years). At 11 years, the cumulative survivorship with revision as the endpoint was 89.8%. Amongst the 88 acetabular revisions for aseptic loosening, 21 had pre-existing autologous lateral structural bone graft from the primary THA (group A). Only 3 (14%) of them required lateral structural re-grafting using allograft at revision. With the remaining 18 hips, the lateral support from the previous graft facilitated revision with no requirement of additional structural graft. Sixty-seven hips did not have lateral structural autograft during primary operation (group B). Amongst them, 18 (27%) required lateral structural allograft in revision surgery. Discussion. There is paucity of evidence regarding long-term results following revision THAs in patients with DDH. Nearly double the number of patients with no previous acetabular structural bone graft needed structural allograft during revision in comparison to those patients with autologous structural bone grafting done at primary operation. The lateral structural autograft used at primary arthroplasty seems to provide invaluable bone stock for future revisions. Conclusion. This study reports the largest number of revision THAs with primary diagnosis of DDH with the longest follow up. In our experience, the lateral support from the structural graft done in primary operation appears to have provided benefit in subsequent revision socket fixation

To confirm whether developmental dysplasia of the hip has a risk of hip impingement, we analysed maximum ranges of movement to the point of bony impingement, and impingement location using three-dimensional (3D) surface models of the pelvis and femur in combination with 3D morphology of the hip joint using computer-assisted methods. Results of computed tomography were examined for 52 hip joints with DDH and 73 normal healthy hip joints. DDH shows larger maximum extension (p = 0.001) and internal rotation at 90° flexion (p < 0.001). Similar maximum flexion (p = 0.835) and external rotation (p = 0.713) were observed between groups, while high rates of extra-articular impingement were noticed in these directions in DDH (p < 0.001). Smaller cranial acetabular anteversion (p = 0.048), centre-edge angles (p < 0.001), a circumferentially shallower acetabulum, larger femoral neck anteversion (p < 0.001), and larger alpha angle were identified in DDH. Risk of anterior impingement in retroverted DDH hips is similar to that in retroverted normal hips in excessive adduction but minimal in less adduction. These findings might be borne in mind when considering the possibility of extra-articular posterior impingement in DDH being a source of pain, particularly for patients with a highly anteverted femoral neck. Cite this article: Bone Joint J 2014;96-B:580–9

In this prospective study a total of 80 consecutive Chinese patients with Crowe type I or II developmental dysplasia of the hip were randomly assigned for hip resurfacing arthroplasty (HRA) or total hip replacement (THR). Three patients assigned to HRA were converted to THR, and three HRA patients and two THR patients were lost to follow-up. This left a total of 34 patients (37 hips) who underwent HRA and 38 (39 hips) who underwent THR. The mean follow-up was 59.4 months (52 to 70) in the HRA group and 60.6 months (50 to 72) in the THR group. There was no failure of the prosthesis in either group. Flexion of the hip was significantly better after HRA, but there was no difference in the mean post-operative Harris hip scores between the groups. The mean size of the acetabular component in the HRA group was significantly larger than in the THR group (49.5 mm vs 46.1 mm, p = 0.001). There was no difference in the mean abduction angle of the acetabular component between the two groups. Although the patients in this series had risk factors for failure after HRA, such as low body weight, small femoral heads and dysplasia, the clinical results of resurfacing in those with Crowe type I or II hip dysplasia were satisfactory. Patients in the HRA group had a better range of movement, although neck-cup impingement was observed. However, more acetabular bone was sacrificed in HRA patients, and it is unclear whether this will have an adverse effect in the long term

INTRODUCTION:. Management of developmental dysplasia of hip in adult is challenging and needs more to be understood in terms of ideal implant, position of acetabulum and operative technique. Patient may present very late, usually when osteoarthritic changes develop followed by pain. Operative management is difficult because of hypoplastic femoral medullary canal and shallow acetabulum filled with soft tissues. Altered anatomy of neurovascular structures also pose a risk of being injured during surgery. AIMS:. The goal of this study was to evaluate late results of total hip arthroplasty in adults after a minimum of 5 years follow-up. MATERIAL:. 45 Total hip arthroplasties in 40 patients were performed for painful hip dysplasia between 2003 and 2012. These 45 procedures were performed in 40 patients mean aged 32 +/− 14 years [17–56]. 29 patients (32 hips) were males and 11 patients (13 hips) were females. Non cemented total hip arthroplasty was done in all cases with mean follow up of 6 years. Of the 45 hips, 6 were neglected, dislocated hips with proximal migration of femoral head. In such patients sub-trochanteric osteotomy was done to bring the femoral head up to the level of Acetabulum. 5 patients (5 hips) were lost to follow up; consequently, the functional results were evaluated for 40 hips (35 patients). Harris hip score was used to evaluate the functional and clinical results. RESULTS and CONCLUSION:. Harris hip score improved in all patients. We concluded from this series that total hip replacement should be considered in all patients with painful dysplastic hip. Key words: Developmental Dyplasia Hip, Total Hip Arthroplasty

Aim. The aim of this study is to assess the effectiveness of clinic based ultrasound screening by Orthopaedic surgeon for early diagnosis and treatment of developmental dysplasia of hip (DDH) in one stop clinic. Methods. This prospective study included 395 infants (185 male and 210 female) (5.2% of study population) who were referred for screening on the basis of abnormal findings or the presence of risk factors for DDH. Average age was 12.5 weeks (1 day to 15 months). All infants were assessed for risk factors of DDH. Clinical examinations were performed by the senior author followed by ultrasonography of both of the infant's hips, using the Graf's technique. Alpha and beta angles were calculated and hips were classified according to Graf's classification system. Results. Out of 790 hips examined 670 (84.8%) were labelled as normal. 120 (15.1%) hips in 84 patients were diagnosed as dysplastic or dislocated. Clinical examination only detected 39 patients out of 84, sensitivity of 46%. Average age of diagnosis was 12 weeks (3days-11 months). 79 patients were successfully treated with pavlic harness, 2 required traction and 3 were referred for surgical treatment. There were 14 cases of late diagnosis during one year period (> 4 months of age) (1.8/1000). Conclusion. Selective ultrasound screening is effective in early diagnosis of DDH and significantly reduces the duration of non operative treatment as well as the need for surgical intervention but does not completely eliminate late diagnosis of DDH. We find the concept of one stop DDH clinic highly effective and recommend that ultrasound training should be a part of orthopaedic curriculum

There are a growing number of younger patients with developmental dysplasia of hip, proximal femoral deformity and osteonecrosis seeking surgical intervention to restore quality of life, and the advent of ISTCs has resulted in a greater proportion of such cases being referred to existing NHS departments. Bone-saving hip athroplasty is often advocated for younger active patients, as they are potential candidates for subsequent revision arthroplasty. If resurfacing is contraindicated, short bone-conserving stems may be an option. The rationale for short stems in cementless total hip arthroplasty is proximal load transfer and absence of distal fixation, resulting in preserved femoral bone stock and avoidance of thigh pain. We have carried out 17 short stem hip replacements (Mini-hip, Corin Medical, Cirencester, UK) using ceramic bearings in 16 patients since June 2010. There were 14 females and 2 males, with a mean age of 50.1 years (range 35–63 years) at the time of the surgery. The etiology was osteoarthritis in 11, developmental dysplasia in 4, and osteonecrosis of the femoral head in one patient. All operations were performed through a conservative anterolateral (Bauer) approach. These patients are being followed and evaluated clinically with the Harris and Oxford hip scores, with follow-up at 6 weeks, 3 months, and annually thereafter. Initital results have been encouraging in terms of pain relief, restoration of leg length (one of the objectives in cases of shortening) and rage of movement. Radiological assessment has shown restoration of hip biomechanics. Specific techniques are required to address varus, valgus and femoral deformity with leg length inequality. There are two main groups of short stems, those that are neck-preserving and those that do not preserve the femoral neck. The latter group requires traditional techniques for revision. Another feature that differentiates them is the availability of modularity. The device we employed is neck-preserving and available with different neck lengths and offsets, which help in restoration of hip biomechanics. The advantage of such short stems may be preservation of proximal femoral bone stock, decreased stress shielding and the ease of potential revision. Such devices may be a consideration for patients with malformations of the proximal femur. Long-term follow-up will be of value in determining if perceived benefits are realised in practice

Through the paediatric LCP Hip plating system (Synthes GmBH Eimattstrasse 3 CH- 4436 Oberdorff), the highly successful technique of the locking compression plate used in adult surgery, has been incorporated in a system dedicated to pediatrics. We are presenting the outcome of the paediatric LCP hip plating system used for a variety of indications in our institution. We retrospectively reviewed the notes and radiographs of all those children who have had Paediatric LCP Plate for the fixation of proximal femoral osteotomy and proximal femur fractures in our institution, between October 2007 and July 2010, for their clinical progress, mobilization status, radiological healing and any complications. Forty-three Paediatric LCP hip plates were used in forty patients (24 males and 13 females) for the fixation of proximal femoral osteotomies (n=40) and proximal femur fractures (n=3). The osteotomies were performed for a variety of indications including Perthes disease, developmental dysplasia of hip, Cerebral Palsy, Down's syndrome, coxa vara, Leg length discrepancy and previous failed treatment of Slipped Upper Femoral Epiphysis. Twenty-five children were allowed touch to full weight bearing post operatively. Two were kept non-weight bearing for 6 weeks. The remaining 13 children were treated in hip spica due to simultaneous pelvic osteotomy or multilevel surgery for cerebral palsy. All osteotomies and fractures radiologically healed within 6 months (majority [n=40] within 3 months). There was no statistically significant difference (p= 0.45) in the neck shaft angle between the immediately postoperative and final x-rays after completion of bone healing. Among the children treated without hip spica, 1 child suffered a periprosthetic fracture. Of the children treated in hip spica, 2 had pressure sores, 3 had osteoporotic distal femur fractures and 2 had posterior subluxations requiring further intervention. There were no implant related complications. The Paediatric LCP Hip Plate provides a stable and reliable fixation of the proximal femoral osteotomy performed for a variety of paediatric orthopaedic conditions

Aim: Many risk factors for DDH are well documented. This study was undertaken to investigate whether multiple pregnancy is a risk factor for developmental dysplasia of hips. Method: During a 10-year period from 1989 to 1998, 39826 newborn babies had their hips scanned. Of these, 1022 (2.6%) babies were non-singletons. Inclusion criteria for our study were all non-singletons, who had their hips scanned in the þrst week after birth. We analyzed the results of their hip scans and calculated the risk for developing DDH either alone or with other risk factor and other variables like the gender, mode of delivery, birthweight and the length of pregnancy. Results: Of the 1022 babies, 825 (80.7%) had their hips scanned in the þrst week. M: F: 49.6%: 50.4%. We had 397 sets of twins, 9 sets of triplets and 1 set of quadruplet. 78% of this group had a normal presentation. 21% (181) of these babies were breech. There was no family history associated with any of the multiple births. Ultrasound abnormality was seen in 30 hips (1.8%). 1 patient had Pavlik harness treatment for persistent ultrasound abnormality. No signiþcant correlation was seen in the gender or in the length of pregnancy. Conclusion: Though it is a general impression that the hips of the non-singletons are under high mechanical stress during pregnancy and would be expected to have a relatively high incidence of DDH, from our study it is evident that the risk is no greater than the normal singletons

Purpose: The outcome of primary total hip arthroplasty (THA) after a previous paediatric hip disease was studied in data from the Norwegian Arthroplasty Register (NAR). Materials and Methods: 72,301 primary THAs were reported to the NAR for the period 1987 – February 2002. Of these, 5,459 (7.6%) were performed because of sequela after developmental dysplasia of hip (DDH), 737 (1.0%) because of DDH with dislocation, 961 (1.3%) because of Perthes’/ slipped femoral capital epiphysis (SFCE) and 50,369 (70%) because of primary osteoarthritis (OA). Prosthesis survival was calculated by the Kaplan-Meier method and relative risks for revision in a Cox model with adjustments for age, gender, type of systemic antibiotic, operation time, type of operating theatre and brand of prosthesis. Results: Without any adjustments the THAs for all three groups of paediatric hip diseases had 1.4 – 2.0 times increased risk for revision compared to that of OA (p< 0.001). Due to huge differences in the studied groups, a more homogenous subset of the data had to be analysed. In this subset, only THAs with well documented prostheses, high-viscosity cements and antibiotic prophylaxis both systemically and in the cement were included (16,874 THAs). In this homogenous subset, no differences in the survivals could be detected for DDH without dislocation and for Perthes’/SFCE compared to OA. For DDH with dislocation the revision risk with all reasons for revisions as endpoint in the analyses was increased 3.3 times compared to OA (p< 0.001), 2.7 times with aseptic loosening as endpoint (p< 0.01) and 10 times with infection as endpoint (p< 0.001). Conclusions: If well-documented THAs are used after paediatric hip diseases the results are just as good as after osteoarthritis, except for DDH with dislocation where increased revision risk is found