Aims. To determine the likelihood of achieving a successful closed reduction (CR) of a dislocated hip in developmental dysplasia of the hip (DDH) after failed Pavlik harness treatment We report the rate of avascular necrosis (AVN) and the need for further surgical procedures. Methods. Data was obtained from the Northern Ireland DDH database. All children who underwent an attempted closed reduction between 2011 and 2016 were identified. Children with a dislocated hip that failed Pavlik harness treatment were included in the study. Successful closed reduction was defined as a hip that reduced in theatre and remained reduced. Most recent imaging was assessed for the presence of AVN using the Kalamchi and MacEwen classification. Results. There were 644 dislocated hips in 543 patients initially treated in Pavlik harness. In all, 67 hips failed Pavlik harness treatment and proceeded to arthrogram (CR) under general anaesthetic at an average age of 180 days. The number of hips that were deemed reduced in theatre was 46 of the 67 (69%). A total of 11 hips re-dislocated and underwent open reduction, giving a true successful CR rate of 52%. For the total cohort of 67 hips that went to theatre for arthrogram and attempted CR, five (7%) developed clinically significant AVN at an average follow-up of four years and one month, while none of the 35 hips whose reduction was truly successful developed clinically significant AVN. Conclusion. The likelihood of a successful closed reduction of a dislocated hip in the Northern Ireland population, which has failed Pavlik harness treatment, is 52% with a clinically significant AVN rate of 7%. As such, we continue to advocate closed reduction under general anaesthetic for the hip that has failed Pavlik harness. Cite this article: Bone Jt Open 2021;2(8):594–598

Aims. The objective of this study was to evaluate the clinical and radiological outcomes of patients younger than six months of age with developmental dysplasia of the hip (DDH) managed by either a Pavlik harness or Tübingen hip flexion splint. Methods. Records of 251 consecutive infants with a mean age of 89 days (SD 47), diagnosed with DDH between January 2015 and December 2018, were retrospectively reviewed. Inclusion criteria for patients with DDH were: younger than 180 days at the time of diagnosis; ultrasound Graf classification of IIc or greater; treatment by Pavlik harness or Tübingen splint; and no prior treatment history. All patients underwent hip ultrasound every seven days during the first three weeks of treatment and subsequently every three to four weeks until completion of treatment. If no signs of improvement were found after three weeks, the Pavlik harness or Tübingen splint was discontinued. Statistical analysis was performed. Results. The study included 251 patients with Graf grades IIc to IV in 18 males and 233 females with DDH. Mean follow-up time was 22 months (SD 10). A total of 116 hips were graded as Graf IIc (39.1%), nine as grade D (3.0%), 100 as grade III (33.7%), and 72 as grade IV (24.2%). There were 109 patients (128 hips) in the Pavlik group and 142 patients (169 hips) in the Tübingen group (p = 0.227). The Tübingen group showed a 69.8% success rate in Graf III and Graf IV hips while the success rate was significantly lower in the Pavlik group, 53.9% (p = 0.033). For infants older than three months of age, the Tübingen group showed a 71.4% success rate, and the Pavlik group a 54.4% success rate (p = 0.047). Conclusion. The Tübingen splint should be the preferred treatment option for children older than three months, and for those with severe forms of DDH such as Graf grade III and IV, who are younger than six months at time of diagnosis. The Tübingen hip flexion splint is a valid alternative to the Pavlik harness for older infants and those with more severe DDH. Cite this article: Bone Joint J 2021;103-B(5):991–998

Developmental Dysplasia of the Hip (DDH) is the most common orthopaedic disorder in newborns. Whilst the Pavlik harness is one of the most frequently used treatments for DDH, there is immense variability in treatment parameters reported in the literature and in clinical practice, leading to difficulties in standardising teaching and comparing outcomes. In the absence of definitive quantitative evidence for the optimal Pavlik harness management strategy in DDH, we addressed this problem by scientifically obtaining international expert-based consensus on the same. An initial list of items relevant to Pavlik harness treatment was derived by systematic review of the literature according to PRISMA criteria and reviewed by two expert clinicians in DDH management. Delphi methodology was used to guide serial rounds of surveying and feedback to content matter experts from the International Hip Dysplasia Institute (IHDI), a collaborative group of paediatric orthopaedic surgeons with expertise in the management of DDH. Rounds of surveying continued in the same manner until consensus was reached. Importance ratings were derived from each round of surveying by calculating median score responses on the 5-point Likert scale for each item. Items requiring clarification or those with a median score of below 4 (“agree”) were modified as needed prior to each subsequent round. Consensus was considered reached when 90% or more of the items had an interquartile range (IQR) of ≤ 1. This value indicates low sample deviation and is accepted as having achieved consensus. This was followed by a corroboration of face validity to derive the final set of management principles. The literature search and expert review identified an initial list of 66 items in 8 categories relevant to Pavlik harness management. Four rounds of structured surveying were required to reach consensus. Following a final round of face validity, a definitive list of 33 items in 8 categories met consensus by the experts. These items were tabulated and presented as “General Principles of Pavlik Harness Treatment for DDH” and “Pavlik Harness Treatment by Severity of Hip Dysplasia”. Furthermore, highly contentious items were identified as important future areas of study and will be discussed. We have developed a comprehensive set of principles derived by expert consensus to assist clinicians, and for use as a teaching resource, in the non-operative management of DDH using the Pavlik harness. We have gained consensus on both the general principles of Pavlik harness treatment as well as the detailed treatment of hip subtypes seen across the spectrum of pathology of DDH. Furthermore, this study has also served to generate a list of the most controversial areas in the non-operative management of DDH which should be considered high priority for future study to further refine and optimise the outcomes of children with developmental hip dysplasia

We prospectively studied the benefits and risks of prolonged treatment with the Pavlik harness in infants with idiopathic developmental dysplasia of the hip. Bracing was continued as long as abduction improved. It was started at a mean age of four months (1 to 6.9). Outcome measures were the number of successful reductions, the time to reduction, the acetabular index and evidence of avascular necrosis at follow-up at one year. In 50 infants with 62 subluxated and dislocated hips (42 Graf type III and 20 type IV), 37 were reduced successfully with a mean time to reduction of 13.4 weeks (. sd. 6.8). Bracing was successful in 31 type-III (73.8%) and in only six type-IV hips (20%, p = 0.002). Avascular necrosis was seen in ten hips. Prolonged treatment with the Pavlik harness for developmental dysplasia of the hip over the age of one month can be beneficial in type-III hips, but it is unclear as to whether this is the optimal treatment, since it may postpone the need for closed or open reduction to a more unfavourable age. The use of the Pavlik harness in type-IV hips in this age group is questionable, but if used, prolonged bracing is not advised

Simulated learning is increasingly prevalent in many surgical training programs as medical education moves towards competency based curricula. In orthopaedic surgery, developmental dysplasia of the hip is a commonly treated diagnosis where the standard of care in patients less than six months of age is an orthotic device such as the Pavlik Harness. However, despite widespread use of the Pavlik Harness and the potential complications that may arise from inappropriate application, no formal educational methods exist. A video and model based simulated learning module for Pavlik Harness application was developed. Two novice groups (residents and allied health professionals) were exposed to the module and at pre-intervention, post-intervention and retention testing were evaluated on their ability to apply a Pavlik Harness to the model. Evaluations were completed using a previously validated Objective Structured Assessment of Technical Skill (OSATS) and a Global Rating Scale (GRS) specific to Pavlik Harness application. A control group who did not undergo the module was also evaluated at two time points to determine if exposure to the Pavlik Harness alone would affect ability. All groups were compared to a group of clinical experts who were used as a competency benchmark. Statistical analysis of skill acquisition and retention was conducted using t-tests and ANOVA. Exposure to the learning module improved resident and allied health professionals' competency in applying a Pavlik Harness (p<0.05) to the level of expert clinicians and this level of competency was retained one month after exposure to the module. Control subjects who were not exposed to the module did not improve nor did they achieve competency. The simulated learning module has been shown to be an effective tool for teaching the application of a Pavlik Harness and learners demonstrated retainable skills post intervention. This learning module will form the cornerstone of formal teaching for Pavlik Harness application in developmental dysplasia of the hip

Aims. There is no consensus regarding optimum timing and frequency of ultrasound (US) for monitoring response to Pavlik harness (PH) treatment in developmental dysplasia of the hip (DDH). The purpose of our study was to determine if a limited-frequency hip US assessment had an adverse effect on treatment outcomes compared to traditional comprehensive US monitoring. Methods. This study was a single-centre noninferiority randomized controlled trial. Infants aged under six months whose hips were reduced and centred in the harness at initiation of treatment (stable dysplastic or subluxable), or initially decentred (subluxated or dislocated) but reduced and centred within four weeks of PH treatment, were randomized to our current standard US monitoring protocol (every clinic visit) or to a limited-frequency US protocol (US only at end of treatment). Groups were compared based on α angle and femoral head coverage at the end of PH treatment, acetabular indices, and International Hip Dysplasia Institute (IHDI) grade on one-year follow-up radiographs. Results. Overall, 100 patients were included; 42 patients completed the standard protocol (SP) and 40 completed the limited protocol (LP). There was no significant difference in mean right α angle at the end of treatment (SP 70.0° (SD 3.2°) ; LP 68.7° (SD 2.9°); p = 0.033), nor on the left (SP 69.0° (SD 3.5°); LP 68.1° (SD 3.3°); p = 0.128). There was no significant difference in mean right acetabular index at follow-up (SP 23.1° (SD 4.3°); LP 22.0° (SD 4.1°); p = 0.129), nor on the left (SP 23.3° (SD 4.2°); LP 22.8° (SD 3.9°); p = 0.284). All hips had femoral head coverage of > 50% at end of treatment, and all were IHDI grade 1 at follow-up. In addition, the LP group underwent a 60% reduction in US use once stable. Conclusion. Our study supports reducing the frequency of US assessment during PH treatment of DDH once a hip is reduced and centred. Cite this article: Bone Joint J 2022;104-B(9):1081–1088

Introduction: This study examined the cohort of patients selectively screened over a 5 year period with ultrasonography according to our risk factors (positive Ortolani or Barlow manoeuvre, breech presentation, first degree affected relative and talipes equinovarus) for developmental hip dysplasia (DDH). The aims were to evaluate the success of those managed in a Pavlik harness and identify predictive factors for those that failed treatment. Methods: 1181 patients were selectively screened between 1999 and 2004. Of those, 128 patients (189 hips) were identified as having hip instability. Failure was defined as inability to achieve or maintain hip reduction in a Pavlik harness. A proforma was designed to document patients’ risk factors and ultrasound findings at time of initial dynamic ultrasound scan where the senior radiographer and treating consultant were present. Each hip was classified according to Graf type. Acetabular indices were recorded prior to discharge. Results: All 128 patients with hip instability were managed in a Pavlik harness. This was abandoned for surgical treatment in 9 patients (10 hips) giving a failure rate of 5.3 % (0.17 per 1000 live births). All those successfully managed had an acetabular index of less than 30 degrees at follow up (6 – 48 months). 7 hips in the series were classified as Graf type IV, of these, 6 went on to fail management in a Pavlik harness. 67% of those that failed were also breech presentation compared to 22% of those managed successfully. There were no complications associated with management in a Pavlik harness. 16 patients born within our region presented after 12 weeks of age with DDH resulting in a late presentation rate of 0.3 per 1000 live births. Discussion: Our overall rate of selective screening is 14 per 1000 live births with a subsequent treatment rate of 2.3 per 1000 is comparable with other centres. Our rate of failure for DDH in a Pavlik harness 0.17 per 1000 live births is an improvement on any previously published results. Irreducible hips, Graf type IV hips and breech presentation correlated with a high likelihood of treatment failure

Introduction: This study examined the cohort of patients selectively screened over a 5 year period with ultrasonography according to our risk factors (positive Ortolani or Barlow manoeuvre, breech presentation, first degree affected relative and talipes equinovarus) for developmental hip dysplasia (DDH). The aims were to evaluate the success of those managed in a Pavlik harness and identify predictive factors for those that failed treatment. Methods: 728 patients were selectively screened between 1999 and 2004. Of those, 128 patients (189 hips) were identified as having hip instability. Failure was defined as inability to achieve or maintain hip reduction in a Pavlik harness. A proforma was designed to document patients’ risk factors and ultrasound findings at time of initial dynamic ultrasound scan where the senior radiographer and treating consultant were present. Each hip was classified according to Graf type. Acetabular indices were recorded prior to discharge. Results: All 128 patients with hip instability were managed in a Pavlik harness. This was abandoned for surgical treatment in 9 patients (10 hips) giving a failure rate of 5.3 %. All those successfully managed had an acetabular index of less than 30 degrees at follow up (6 – 48 months). 7 hips in the series were classified as Graf type IV, of these, 6 went on to fail management in a Pavlik harness. 67% of those that failed were also breech presentation compared to 22% of those managed successfully. There were no complications associated with management in a Pavlik harness. Discussion: Our overall rate of selective screening is 14 per 1,000 with a subsequent treatment rate of 2.3 per 1,000, which is comparable with other centres. Our rate of failure for DDH in a Pavlik harness (5.3 %) is extremely encouraging. Graf type IV hips and breech presentation correlated with a high likelihood of treatment failure

Aims:. To assess the success rate of closed reduction after failing Pavlik harness for treatment of DDH. Methods:. It was a retrospective review of prospectively collected data. Patient's notes/computerised records were reviewed. Radiological investigations were also reviewed. Microsoft excel used for descriptive stats. Results:. From 1998 to 2011, 975 patients (1322 hips) were treated with Pavlik harness. Of these, 188 (20%) were male and 787 (80%) were female patients. The Pavlik Harness was successful in 92% patients and failed in 8% (102) patients. These 102 patients underwent closed reduction under general anaesthesia. Of these, the closed reduction was successful in 33 (20%) patients and failed in 69(68%) patients who then underwent open reduction. Conclusion:. The Success of closed reduction in patients with failed Pavlik Harness is low. Closed reduction may not overcome intrinsic and extrinsic obstructing factors responsible for failure of Pavlik Harness. Level of evidence: IV

Sixty-nine hips in 62 patients were treated by the Pavlik harness for congenital dislocation. Ultrasonography showed three degrees of residual head displacement when the harness was first applied. In type A, the femoral head showed contact with the inner posterior wall of the acetabulum. In type B, it contacted the posterior margin of the socket, with its centre at or anterior to the acetabular rim. In type C, the femoral head was displaced outside the socket, with its centre posterior to the acetabular rim. All 51 hips with type A displacement remained reduced. Of nine hips of type B, five were reduced, but the other four were not. None of the nine hips with type C dislocation became reduced with continued use of the harness. The Pavlik harness is indicated for type A and some type B dislocations, but the latter need daily ultrasound monitoring, with a change in method of treatment if type C displacement appears or if the hip is not reduced within one or two weeks. Treatment by Pavlik harness is not indicated in hips with type C dislocations

Aim: To assess whether use of the Pavlik harness for the management of developmental dysplasia of the hip (DDH) can safely be discontinued without weaning. Method: The study group comprised babies diagnosed with DDH at the Royal Liverpool Children’s hospital over a 10 year period, between January 1995 and August 2004. The decision to instigate treatment with a Pavlik harness was based upon the Graf grade. We used Graf IIB or worse as our treatment threshold for the use of the Pavlik harness. In our practice the harness was removed when the hips were ultrasonographically and clinically normal, without a period of weaning. Results: There were 368 hips (273 babies) for analysis, 178 cases of unilateral DDH (128 left hips and 50 right hips) and 95 bilateral cases. Mean age at diagnosis was 59 days (range 1 – 187 days) with twenty-six patients presenting late after the usual 120 day time limit. Treatment with the Pavlik harness was successful in normalising 323 hips (87.8%). The Pavlik harness was unsuccessful in reducing 45 dislocations (12.2%). Patients were followed-up for a mean of 4.1 ± 2.7 years with no deterioration of acetabular indices on plane radiographs, according to the Tonnis classification. There were 4 hips with possible grade I avascular necrosis. To date there have been no cases of late dysplasia. Conclusions: Although many units remove the harness after a period of gradual weaning, practice is varied. Since we did not encounter any negative outcome despite not weaning we conclude that that weaning is unnecessary

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

We reviewed the medical records of 115 patients with 130 hips with developmental dysplasia with complete dislocation in the absence of a neuromuscular disorder, spontaneous reduction with a Pavlik harness, and a minimum of 14 years’ follow-up. The mean age at the time of harness application was 4.8 months (1 to 12) and the mean time spent in the harness was 6.1 months (3 to 12). A total of 108 hips (83.1%) were treated with the harness alone and supplementary surgery for residual acetabular dysplasia, as defined by an acetabular index > 30°, was performed in 22 hips (16.9%). An overall satisfactory outcome (Severin grade I or II) was achieved in 119 hips (91.5%) at a mean follow-up of 16 years (14 to 32) with a follow-up rate of 75%. Avascular necrosis of the femoral head was noted in 16 hips (12.3%), seven of which (44%) underwent supplementary surgery and nine (56%) of which were classified as satisfactory. The acetabular index was the most reliable predictor of residual acetabular dysplasia

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

We analysed the incidence of avascular necrosis in 101 hips of 90 infants with congenital dislocation treated with the Pavlik harness and followed up for more than one year. Using ultrasonography in the flexed-abducted position the hips were classified as type A when the femoral head was displaced posteriorly, but within the socket and making contact with the posterior inner wall of the acetabulum; type B when it was in contact with the posterior margin of the acetabulum, with its centre at this level or anterior to it; and type C when it was displaced out of the socket, with its centre posterior to the posterior rim of the acetabulum. Eighty-seven hips were reduced by the harness (86%), and seven of these developed avascular necrosis (8%). All 69 hips with type-A dislocation were reduced, and only one (1.4%) showed slight avascular necrosis. Eighteen (78.3%) of 23 hips with type-B dislocation were reduced, and six developed avascular necrosis (33.3%). In one hip, the femoral head was severely damaged. None of the nine hips with type-C dislocation was reduced in the harness. We conclude that the Pavlik harness is indicated for type-A, but not for type-B or type-C dislocations

We report the six-year results of a prospective, controlled demographic trial of developmental dysplasia of the hip (DDH) treated in the Pavlik harness using ultrasound supervision. Our aim was to assess the value of ultrasound and its role in monitoring reduction in the harness, in terms of progression or failure of reduction at an early state. From 1988 to 1994, a total of 221 patients with 370 ultrasonographically abnormal hips was treated in the Pavlik harness. This represents a treatment rate for the Southampton district of 5.1 per 1000 live births. Sixteen hips in 12 patients were not reduced in the harness and required surgical treatment; 95.7% were successfully reduced. One case of mild avascular necrosis (0.3%) was identified in those treated by harness alone. Of the 221 patients 87.8% remain under radiological review, with 3.2% of affected hips showing continued, mild acetabular dysplasia. We conclude that ultrasound monitoring has led to an acceptably low level of intervention, a high reduction rate and minimal iatrogenic complications. The trial is continuing

Introduction: 1986 we started with ultrasound screening for congenital dislocation of the hip (CDH) in all newborn children from our hospital. In 1995 an regime was investigated we developed out of our expieriences of the previous years and started a prospective study. Material and methods: In the period 1995 to 2006 we did ultrasound screening in newborn babies within the first week of life. There were 14744 ultrasound checkups in 7372 children. Following the classification of Graf we had 7213 children with stage Ia,Ib or IIa. In 159 children (2,15%) we saw a ultrasound measurement stage IIc or worse (D,IIIa/b; IV a/b) which was an indication for treatment with the Pavlik bandage. Over all we treated 203 dysplastic hips with our regime. By dedecting a congenital dislocated hip we applyed the Pavlik harness immediately after diagnosis in 110 degrees of flection an 45 degrees of abduction. The fist controll reviewing the compliance of the parents and the setting of the bandage was 10 to 14 days after starting treatment. Every 10 to 14 days we did bandage checks combined with ultrasound controlls. We stopped treatment with the pavlik harness when the ultrasound showed a mature, well developed picture of both hips compared to Graf stage Ia/b. Results: We treated 159 newborn with 203 dislocated hips. There were 131 (82.4%) female an 28 (17.6)% male patients. 100 right (49.5%) and in 103 left (50.5%) hips. The distribution following Graf classification were 150 for typ IIc (73.9%), 18 for type D (8.9%), 31 for type IIIa/b (15.3%) and 4 type IVa/b (1.9%). Summerizing there were 150 hips, stage IIc (73,9%), to be at risk to develope an luxation, but 53 (26,1%) hips were already luxated at the moment of birth. The average treatment time over all was 53 days (7,6 (3–26) weeks). Subdividing the groups the treatment period for stage IIc was in mean 7.6 weeks, for stage D 7.1 weeks, for stage III a/b 9.5 weeks and for stage IV a/b 9 week. We had a lost to follow up in 4 (1,81%) patients (3 times compliance problems with the parents at stage II a in both sides). Once we had to treat with a so called Fettweiss-cast after one week of therapy because the baby was to small for the bandage but in the other cases there was no need für additional methodes of treatment. At no time we ever had a degradation of the disease. Furthermore we had no necrosis of the femoral head in our study population. Conclusion: The treatment with the Pavlik bandage of the CDH in every stage in newborn was possible and showed good result in 203 hips. To establish a standardised therapy you have to do an area-wide ultrasound screening as well as an consistently follow up of your therapy

Introduction: The Pavlik harness is widely used in the management of developmental dysplasia of the hip and its efficacy in the treatment of instability and acetabular dysplasia is well established. There are some hips which although reducible consistently fail to stabilise in a harness irrespective of the age of application. We report three cases in which through altering the method of application of the harness, stability and subsequent normal development was achieved. Method: Three patients age one week, six weeks and twelve weeks failed to stabilise in a harness applied in the conventional fashion. By rerouting the posterior “abduction strap” in front of the anterior “flexion” strap and attaching it as usual distally we observed improved abduction and more restriction of movement such that the unstable hip was held reduced. Reduction was confirmed by anterior ultrasound. The harness was converted back to the conventional application at four weeks by which time all of the hips had stabilised clinically. It was retained for a further eight weeks. Results: Significant dysplasia was evident in all three hips at presentation ( alpha angles 32, 48 and 34). At average follow up of 23 months all hips were concentrically reduced with no significant persisting dysplasia nor evidence of avascular necrosis. Discussion: Early reduction and stabilisation of the femoral head in DDH is important if subsequent intervention is to be minimised and it has been suggested that the more rigid Von Rosen splint is more effective than the Pavlik in achieving this. Our early experience with this simple modification has been successful in treating three unstable hips which would otherwise have failed splintage in our hands. We recommend it as an option to consider in the unstable hip, in conjunction with anterior ultrasound to confirm that reduction has been achieved from the outset

Ultrasound was used to observe the entire course of spontaneous reduction of CDH in the Pavlik harness in nine infants. In six infants with Suzuki type-A dislocations, the femoral head settled slowly into the bottom of the acetabulum by gliding on its posterior wall. In type-B dislocations, passive abduction of the legs during sleep caused it to approach the entrance to the socket and then suddenly to slip in. Reduction with the Pavlik harness is due to passive mechanical factors, and occurs only during muscle relaxation in deep sleep: no active movement is involved

We present the results of treatment of developmental dysplasia of the hip in infancy with the Pavlik harness using a United Kingdom screening programme with ultrasound-guided supervision. Initially, 128 consecutive hips in 77 patients were reviewed over a 40-month period; 123 of these were finally included in the study. The mean age of the patients at the start of treatment was five weeks (1 to 12). All hips were examined clinically and monitored with ultrasound scanning. Failure of treatment was defined as an inability to maintain reduction with the harness. All hips diagnosed with dysplasia or subluxation but not dislocation were managed successfully in the harness. There were 43 dislocated hips, of which 39 were reducible, but six failed treatment in the harness. There were four dislocated but irreducible hips which all failed treatment in the harness. One hip appeared to be successfully treated in the harness but showed persistent radiological dysplasia at 12 and 24 months. Grade 1 avascular necrosis was identified radiologically in three patients at 12 months