The purposes of this study were to review retrospectively the 25-year survival of cemented and cementless THA for hip dysplasia and to compare the effect of fixation methods on the long-term survival in patients with DDH. We retrospectively reviewed all patients with OA secondary to hip dysplasia treated with a cemented Bioceram hip system between 1981 and 1987, and a cementless cancellous metal Lübeck hip system between 1987 and 1991. The studied subjects were 76 hips of cemented THA (Group-C) and 57 hips of cementless THA (Group-UC). Both hip implants had a 28-mm alumina head on polyethylene articulation. The mean age at operation was 50.5 years (range, 36–60 years) in Group-C and 50.0 years (range, 29–60 years) in Group-UC. The survival at 25 years regarding any revision as the endpoint was 46% in Group-C and 76% in Group-UC. These difference was significant using Log-rank test (P=0.008). The cup survival at 25 years was 47% in Group-C and 83% in Group-UC (P= 0.0003). The stem survivals at 25 years were 95% in Group-C and 92% in Group-UC. (P= 0.416). Cementless THA in patients with DDH showed a higher survival rate at 25 years than cemented THA because of the excellent survival of the acetabular component without cement. We conclude that cementless THA with the cancellous metal Lübeck hip system led to better longevity at 25 years than cemented THA with the Bioceram in patients with OA secondary to DDH

Introduction. Neck and cup impingement resulted in producing larger amount of wear and risk for dislocation after total hip arthroplasty. DDH had more complex to adjust combined cup and femoral neck anteversion during surgery. Dislocation is the second most prevalent complication in total hip replacement with a 2–4% incidence. These resulted in significant financial burden to health care system. Sixteen million US dollars or more cost had in Japanese health insurance system every year. Purpose of this study was to evaluate neck-cup impingement with neck changeable M/L taper Kinectiv stem for DDH patients. Materials & Methods. Single surgeon's series were analyzed neck cup impingement of 1152 primary total hip surgeries with DDH. 269 hips in men, surgical approach were 754 mini-one antero-lateral, 284 mini- Watson-Jones, and 114 Hardinge. Acetabular cups were seated 20 degrees anteversion. Kinectiv Stem (Zimmer, Warsaw, IN) was inserted manually with standard technique. Femoral head selection was performed 26mm CoCr basis. 32mm were used for 75 years old or more, and 36mm were 80 years or older. First trial was performed with straight type of neck and 26mm femoral head based on preoperative templating. At neck and head trial to evaluated antero-superior impingement with “flex+add.+IR” and postero-inferior impingement with “ext.+add.+ER”. If the neck and cup impingement occurred even if no dislocation, necks were replaced counter version or larger offset. Results. Neck trial was 2 to 3 times during surgery (ave. 1.9). Version was changed 395(33%) cases. Surgeon selected larger offset in 246, 235 longer length, 99 shorter length. Larger offset with longer length were used in 229 (20%), 117 (10%) had larger offsets and shorter length compared to 2D templating before surgery. We had 2 dislocations (0.48%) with10 degree extended lip PE (2/359: 0.56%) and 2 for flat PE liner (2/793: 0.25%) fixed with manual reduction. All were using very short neck (E; minus 4 in length and S; minus 4 in length, plus 4 in offset) with smaller arc of movement type because of tight to redact compared expected proper positions. All dislocated cases were revised with larger femoral head. Our first series of 1500 Versys system with 10 degree extended lips had 0.74% (14/1880) (2004–9) dislocation rate. Kinectiv neck changeable stem had 66% reduction of dislocation rate (p<0.05). Averaged hospital stay was 7 (3–12) days. Discussion. One Kinectiv stem had 60 variety of necks based on 4 mm head center difference. Large amount of variation especially anteverted or retroverted neck selection might reduce neck-cup impingement compared to other straight type of femoral stems. Combined anteversion is very important especially in DDH patients, because of larger femoral anteversion. Proper offset and leg length are also very important issues for any type of patients. This type of stem had more advantages than straight type monolithic stems to reduce wear and dislocation caused by impingement. Care must be taken for reducing impingement with selecting shorter length or offset during surgery. Lower dislocation rate are very effective to health insurance system

Purpose. Dysplastic acetabulum (DDH) have some difficulty even if with conventional approach of THA. Indication or contraindication is not clear with MIS THA. The purpose of this study was to evaluate complications with mini antero-lateral approach for DDH patients. Materials & Methods. 1523 DDH hips were evaluated. Follow-up periods were averaged 36 mos. (24–74). 612 were Crowe I, 628 of II, and 283 of III. Crowe IV hips were contra-indicated. Leg length discrepancy (LLD) before and after surgery, OR time, complications during and after surgery, and length of hospital stay were evaluated. Results. Average LLD before surgery was 1.3cm in Crowe I, 1.8cm in II, 3.3cm in III, but recovered within 5 mm after surgery. Average OR time was 56 minutes, 68, and 96 (p<0.05), respectively. Crowe II with contractured hips had more OR time (>75 min) compared to no contractured hips (<65 min) (p<0.05). Three of type I, 4 of II, 6 of III with osteoporosis and contractured hip patients had posterior trochanteric tip fracture within 2 weeks because of disuse bone atrophy or obesity (BMI>30). Two acetabular cups were revised with Crowe III because of surgical errors. We had 8 dislocations, 2 infections and 12 anterior calcar linear fractures, but fixed with wiring. No other complication has occurred. After 300 cases, lerning curve was stable around 60 minutes in skin to skin surgical time. Harris hip score was improved 92 at the final follow-up. Discussion & Conclusion. Crowe I and II patients had no severe complication. Care must be taken for Crowe III with 2.5cm or more LLD with contractured hip, severe osteoporosis, or anteverted femoral neck. These type of patients need to change conventional approach. Capsular release around piriformis fossa need to make a proper alignment before stem broaching. Care must be taken for obtaining proper combined anteversion of DDH with higher femoral neck anteversion

Background. There are many difficulties during performing total hip replacement in high riding DDH. These difficulties include:. In Acetabular part: bony defect in antero lateral acetabular wall/finding true centre of rotation/shallowness of true acetabulum/hypertrophied and thick capsular obstacle between true and false acetabulum. In Femoral part: small diameter femoral shaft/excessive ante version/posterior placement of greater trochanter. anatomic changes in soft tissue & neurovascular around the hip including: adductor muscle contracture/shortening of abductor muscles/risk of sciatic nerve injury following lengthening of the limb after reduction in true acetabulum/vascular injury. The purpose of this lecture is how to manage above problems with using reinforcement ring (ARR) for reconstruction of true acetabulum and step cut L fashion proximal femoral neck shortening osteotomy in a single stage operation. Method. 23 surgeries in 19 patients, including 18 female and one male were performed by me from Jan. 1997 till Dec. 2009. Six patients had bilateral hip dislocation, but till now only four of them had bilateral stepped operation. Left hip was involved in 15 cases (65.2%). The average age was 40 years old. All hips were high riding DDH according to both hartofillokides and crowe classification. Reconstruction of true acetabulum was performed with aid of reinforcement ring and bone graft from femoral head in all cases. Trochantric osteotomy was done in all, followed by fixation with wire in 22 cases which needed two revisions due to symptomatic non union (9%). Hooked plate was use in one case for trochantric fixation. Due to high riding femur, it was necessary to performed femoral shortening in neck area as a step cut L fashion. In two patient, one with bilateral involvement, after excessive limb lengthening following trial reduction, it was necessary to performed concomitant supracondylar femoral shortening. (3 cases = 13%). 22 mm cup & miniature muller DDH stem were used in 18 cases (78.26%). In 5 cases, one bilaterally, non cemented stem and 28 mm cemented cup in ring were used. Primary adductor tenotomy was performed in 9 cases. Secondary adductor tenotomy needed in 2 cases (totally = 47.82%). Repair of iatrogenic femoral artery tear after traction injury with retractor, occurred in 2 cases (8.69%). All patients evaluate retrospectively. Average follow up month is 68.7. Results. One case of left acetabular component revision due to painful bony absorption in infero medial part of ring with poor inclination wad done, after 2 years of primary operation. Know after 13 years she has had early signs of stem loosening in the same side. Another acetabular component revision following traumatic dislodgment of cup and cement from ring was performed after 13 months from primary operation. Again she had poor implant inclination. So revision rate is 8.69%. (One case will need revision in near future, so the revision rate will increase to 13%) Radiological wires breakage which were used for greater trochanteric fixation, could be seen in 11 cases (47.82%), but only two of them with functional impairment needed to re-fixation with Menen plate(18.18% of trochanteric non union). Average limb lengthening after operation is 4.3 Cm (2-7 Cm). Only one case of transient Sciatic nerve paresis had happened for 2 months followed by complete recovery. Two case of secondary adductor tenotomy wre done, one after traumatic dislocation of prosthesis with pubic fracture, and the other one after restriction of hip abduction. The average Harris hip score from 23 pre -operatively has been increase to 85.38. (The pre op. scores were 12.625 – 40.775/The post op. scores were 64.92 – 96). No post operative infection was seen. Discussion. This is a midterm follow up survey, but 7 cases have more than 9 years follow up with only one stem loosening (11% long term loosening rate). It is a challenging procedure for performing joint replacement in high riding DDH, if so using reinforcement ring with graft for true acetabulum reconstruction and getting primary proximal femoral shortening in a step cut L fashion around the lesser trochanteric region would be a worthy procedure. In high riding DDH due to hypoplasia of lesser trochanter, there is not a significant difference in bone resistance and it is possible to get shortening in this area without fearing of deco promising bony stability. The average shortening is 3 Cm. In specific cases with more severe contracture for preventing neuro-vascular complication, concomitant shortening osteotomy in supracondylar area is recommended. Although greater trochanter fibrous union has produced less functional impairment, but a better technique should be considered. Distal and lateral advancement of osteotomised greater trochanter lead to better abductor muscle performance and less limp. Adductor tenotmy has a great importance in contracted soft tissue, so in any case with abduction limitation it should be performed

Purpose of the study. This study aims to evaluate the use of closed reduction of hips with developmental dysplasia of the hip (DDH) and medial open reduction of these hips as a subsection of closed reduced hips. Methods. The study was a retrospective analysis of treatment of 30 children with developmental dysplasia of the hip (DDH). These children were taken from a consecutive series of children treated over a period from June 2000 to 2011 with closed reduction by a single surgeon. The ages at the time of diagnosis were between 1 day and 13 months (mean 5.25 weeks). Included in this series are 7 patients treated with medial open reduction, all done with the Ludloff approach. Follow up of these patients was from 8 months to 12 years (mean 5 years). All patients needing secondary procedures were noted. The X- rays were evaluated for percentage acetabulum cover in patients over the age of 8 and improvement of the acetabular index in all these patients. Results. 4 children needed secondary procedures. 1 child of the closed reduction group developed avascular necrosis of the femoral head that was treated with a Salter osteotomy and a further 2 needed secondary open reductions after redislocation following initial closed reduction. One child with bilateral open medial reductions had a Salter osteotomy 6 years after the initial treatment was done. 26 of the children had good outcomes with improvement of the acetabular angles, percentage acetabular cover and pain free independent ambulation. The average acetabular index improved from 37.5° to 23.3°. Conclusion. Closed reduction of DDH hips is a good treatment modality. Early treatment allows for acetabular and femoral development. There are minimal secondary procedures necessary after closed reduction, and open medial reduction does not increase the complication rate. NO DISCLOSURES

Restoration of an anatomical hip centre frequently requires limb lengthening, which increases the risk of nerve injury in the treatment of Crowe 4 DDH. The objective was to perform a prospective evaluation of SDTSO with Cemented Exeter Femoral Component. 15 female patients (18 hips – 3 bilateral) with a mean age at time of operation of 51 years were followed-up for a mean of 77 months (11 to 133). 16 cemented and 2 uncemented acetabular components were implanted. Exeter cemented DDH stems were used in all cases. No patient was lost to follow-up. Charnley-d'Aubigné-Postel scores for pain, function and range of movement were improved from a mean of 2, 2, 3 to 5, 4, 5 respectively. One osteotomy failed to unite at 14 months and was revised successfully. Clinical healing was achieved at a mean of 6 months and radiological at a mean of 9 months. The mean length of the excised segment was 3cm and the mean true limb lengthening was 2cm. A 3.5mm DCP plate with unicortical screws was used to reduce the osteotomy, and intramedullary autografting was performed in all cases. Mean subsidence was 1mm and no stem was found loose at the latest follow-up. No sciatic nerve palsy was observed and no dislocation. Cemented Exeter femoral components perform well in the treatment of Crowe IV DDH with SDTSO. Transverse osteotomy is necessary to achieve derotation and reduction can be maintained with a DCP plate. Intramedullary autografting prevents cement interposition at the osteotomy site

Aims. Use of videos for patient education has grown in popularity. Literature promotes the use of videos to provide clearer information to patients and families. Information to patients are often provided via leaflets. In our regional (Cwm Taf Morgannwg University Health board- CTM UHB) one stop clinic, we aimed to pilot the use of an educational video on developmental dysplasia of the hip (DDH) for parents and guardians and assess its usefulness. Methods. Parents and guardians of children being treated for DDH with Pavlick harness were invited to the partake in the pilot scheme. A short video provided by the ‘What? Why? Children in Hospital’ (WWCIH) organisation was shown on a tablet to parents and guardians. A ten question questionnaire was then provided post watching the video. The questionnaire consisted of short answer, multiple choice, and rating scale (1-10) questions. Results. 23 parents/guardians participated. All participants stated the video was of the right duration. Participants of all stages in the Pavlik harness journey found the videos helpful. All participants responded that they would recommend the video to other parents and guardians. 52%(n=12) suggested that the video would be most useful to watch after DDH is diagnosed but before starting treatment. Participants also provided feedback on how to improve the videos such as inclusion of detailed explanations about the harness. Conclusion. The use of an educational video for parents/guardians with children diagnosed with DDH is beneficial, with all participants finding it useful. Other centres could adopt the use of educational videos for newly diagnosed DDH children's families, prior to starting treatment with the Pavlick harness

Introduction. Leg length discrepancy (LLD) in patients with unilateral developmental dysplasia of the hip (DDH) can be problematic for both patients and surgeons. Patients can acquire gait asymmetry, back pain, and arthritis. Surgical considerations include timing of correction and arthroplasty planning. This study audits standing long leg films performed at skeletal maturity in our patients. The aim of this study is to identify if surgical procedure or AVN type could predict the odds of needing an LLD Intervention (LLDI) and influence our surveillance. Materials and Methods. Hospital database was searched for all patients diagnosed with DDH. Inclusion criteria were patients with appropriately performed long leg films at skeletal maturity. Exclusion criteria were patients with non DDH pathology, skeletally immature and inadequate radiographs. All data was tabulated in excel and SPSS was used for analysis. Traumacad was used for measurements and AVN and radiologic outcome grades were independently classified in duplicate. Results. 110 patients were identified. The mean age of follow-up was 15 years with final average LLD of 1mm(±5mm). The DDH leg tended to be longer and length primarily in the femur. 31(28.2%) patients required an LLDI. 19 Patients had a final LLD >1.5cm. There was no statistical significant difference in the odds of needing an LLDI by type of surgical procedure or AVN. AVN type 4 was associated with greatest odds of intervention. The DDH leg was more likely to require ipsilateral epiphysiodesis or contralateral lengthening in Type 1 and 2 AVN. Conclusions. The DDH leg tends to be longer, leg lengths should be monitored, and leg length interventions are frequently required irrespective of previous DDH surgical procedure or the presence of AVN

Developmental dysplasia of the hip (DDH) is the most common paediatric hip condition and is a major cause of hip replacement or osteoarthritis in young adults. Due to potential impact on quality of life, every child is checked at birth for unstable hips. Should instability be detected, or the infant has other DDH risk factors, they are referred for an ultrasound exam and orthopaedic surgeon consultation. Since the implementation of a DDH screening program at our institution, the Radiology Department has seen a dramatic increase in hip ultrasounds performed. While helping prevent the complications of missed DDH diagnoses, this program has placed strain on radiology resources, and often families must attend multiple appointments before receiving a diagnosis and beginning treatment. To mitigate this, we have implemented a pilot point-of-care DDH clinic, where an ultrasound technician performs hip ultrasound exams using a portable ultrasound in the orthopaedic clinic in conjunction with surgeon consultation. The aim of this clinic is to enable diagnosis and treatment in one appointment, reduce referral-to-treatment delays, wait times, and decrease costs and travel time for families while also alleviating strain on radiology resources. A point-of-care DDH test clinic was implemented in the Orthopaedic Department at our institution. Patients referred with suspected/confirmed DDH attended a single orthopaedic clinic appointment. An ultrasound technician was present to perform scans in conjunction with the orthopaedic surgeon's clinical assessment. Surveys were distributed at the end of the appointment to collect feedback on the family's satisfaction with the program, as well as other pertinent demographic information (i.e. occupation, geographic location, travel time to hospital). To date, 40 patients have attended the pilot clinic. Families spent an average 61.3 minutes (range 15–420 minutes) traveling to the hospital for an appointment (122.6 minutes round-trip). This program reduced the number of hospital visits for DDH screening from three (initial consultation, radiology, follow-up) to one per patient, saving an average 245.2 minutes of travel time to/from the hospital per family. Appointment time averaged 35.9 minutes and families rated their satisfaction with appointment length an average of 9.6/10 (35/40 families rated satisfaction 10/10, 1 = very unsatisfied, 10 = very satisfied). Additionally, 33/40 families were also asked to rate their satisfaction with check-in/check-out processes (average 9.4/10), ultrasound screening (average 9.9/10), and time with specialist (average 9.9/10). Satisfaction scores did not differ based on variables such as survey taker's gender, occupation, or geographic location. The pilot point-of-care ultrasound DDH clinic has considerably reduced the number of clinic visits and travel time for families, reduced aggregate clinic wait times, and has resulted in high family satisfaction. This specialized clinic may have potential to free up hospital staff time and resources, possibly decreasing wait times in other clinical areas, ultimately improving quality of care for patients and families across our institution

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

Developmental dysplasia of the hip (DDH) is a common risk factor of early osteoarthritis (OA), with insufficient coverage of the femoral head by the acetabulum which leads to excessive cartilage stresses in the hip joint. Knowledge of the molecular health of cartilage using MRI may diagnose and stage chondral disease, but more importantly allows for treatment stratification and prognostication. Delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) is a validated MRI technique for detecting early loss of proteoglycan (PG). However, it requires an injection of contrast agent and exercise prior to the scan. MRI techniques such as T1ρ and T2 mapping have also been shown to be sensitive to early biochemical changes in cartilage but can be performed without any contrast injection. In this study we evaluate three quantitative MR techniques (dGEMRIC, T1ρ and T2 mapping) in patients with DDH. Our hypothesis is that both T1ρ and T2 correlate with dGEMRIC, and thus may be effective non-contrast based techniques for biochemical cartilage mapping in DDH hips. Seven informed and consented patients (mean age: 31.1 years) with DDH were enrolled in this IRB approved MRI study before surgery. DDH was defined as a lateral center-edge angle under 25º and acetabular index >13º on the plain x-ray. All subjects underwent two successive MRI sessions at 3T: In the first cartilage T1ρ and T2 mapping were performed. After leaving the scanner the subjects were injected with 0.4ml/kg Dotarem (i.v.), walked for 15min and rested for 25min before returning into the MRI. dGEMRIC (T1post) mapping was initiated approximately 45min after the injection. Image post-processing, registration and cartilage segmentation was performed with Matlab. The joint was subdivided into anterior and posterior regions in the sagittal plane and into lateral, intermediate and medial zones in the transverse plane, resulting in six region of interest (ROIs): antero-lateral, antero-intermediate, antero-medial, postero-lateral, postero-intermediate and postero-medial. The correlation between the dGEMRIC and T1ρ and dGEMRIC and T2 were evaluated using Spearman's Rho and tested for significance. The analysis of all six cartilage ROIs for all subjects resulted in a significant (p < 0 .001) negative correlation (Rho = −0.50) between the dGEMRIC index (T1post) and the T1ρ relaxation time. The dGEMRIC index and T2 correlated positive (Rho = 0.55) and significant (p < 0 .001). Although this pilot study has a small sample size a negative correlation between dGEMRIC and T1ρ was found in patients with DDH. Both methods are known to probe the PG content of cartilage, where a decreased PG content leads to lower dGEMRIC index and an increased T1ρ value. The correlation coefficient was moderate, but significant, which shows that T1ρ mapping as an effective tool to probe the cartilage PG content similar to dGEMRIC. A comparable, but positive correlation was found between dGEMRIC and T2. T2 is sensitive to the cartilage collagen content with a decreased T2 value in degenerated cartilage. In symptomatic DDH, where an onset of OA is assumed, both PG depletion and collagen decay are in progress and can be evaluated using these mapping techniques

Introduction. Developmental dysplasia of the hip (DDH) can be managed through a variety of different surgical approaches from closed reduction to simple tenotomies of the adductors and through to osteotomies of the femur and pelvis. The rate of redislocation following open reduction for the treatment of DDH may be affected by the number of intraoperative surgeons. Materials and methods. We performed a retrospective cohort analysis of 109 patients who underwent open reduction with or without bony osteotomies as a primary intervention between 2013 and 2023. We measured the number of redislocations and number of operating surgeons (either 1 or 2 operating surgeons) to assess for any correlation. 109 patients were identified and corresponded to 121 primary hip operations, the mean age at operation was 82.2 months (range 6 to 739 months). During the 10-year period 7 hip redislocations were identified. Results. Of the 7 redislocated hips, the rate of redislocation was found to be higher in patients who had undergone surgery via a single surgeon (5 redislocations) compared to the dual surgeon cohort (2 redislocations), though this did not reach statistical significance. Redislocation was more common in female patients and right laterality 7.2% and 8.7% respectively, though this again did not reach statistical significance. Conclusions. We conclude that a single surgeon approach, female gender and right laterality are potential risk factors for redislocation following open reduction. Further investigation utilising a larger sample size would be required to appropriately explore these potential risk factors further

Introduction. There is little evidence surrounding the clinical implications of a diagnosis of IIa hip dysplasia with no consensus as to its efficacy as a predictor pathological dysplasia or treatment. Therefore, we evaluated the importance of categorising 2a hip dysplasia in to 2a- and 2a+ to better understand the clinical outcomes of each. Methods. A 9-year retrospective cohort study of patients with a diagnosis of type IIa hip dysplasia between 2011 – 2020 (n=341) in our centre. Ultrasound scans were graded using Graf's classification, assessment of management and DDH progression was completed through prospective data collection by the authors. Results. The prevalence of IIa hip dysplasia within our population was 6.7/1000 live births. There was significantly higher incidence of treatment in the IIa- (31.4%, n=17/54) group when compared to the 2a+ group (10%, n=28/287), (p<0.01). In those that had an abnormality (torticollis and/or foot abnormality) treatment rates (24% n=7/29) were significantly (p<0.05) higher than those without anatomical abnormality (15%, n=48/312). Conclusion. This study has demonstrated the significant clinical impact of a IIa- diagnosis on progression to pathological dysplasia and therefore higher rates of treatment in IIa- hips. Furthermore, we have demonstrated the importance of detection of IIa hips through a national screening program, to allow for timely intervention to prevent missing the acetabular maturation window. Therefore, it is our recommendation that all patients with additional anatomical abnormalities and those with a diagnosis of type IIa- hip dysplasia be considered for immediate treatment or urgent follow up following their diagnosis to prevent late conservative intervention

Objective. To three-dimensionally reconstruct the proximal femur of DDH (Developmental dysplasia of the hip) and measure the related anatomic parameters, so that we could have a further understanding of the morphological variation of the proximal femur of DDH, which would help in the preoperative planning and prosthesis design specific for DDH. Methods. From Jan.2012 to Dec.2014, 38 patients (47 hips) of DDH were admitted and 30 volunteers (30 hips) were selected as controls. All hips from both groups were examined by CT scan and radiographs. The Crowe classification method was applied. The CT data were imported into Mimics 17.0. The three-dimensional models of the proximal femur were then reconstructed, and the following parameters were measured: neck-shaft angle, neck length, offset, height of the centre of femoral head, height of the isthmus, height of greater trochanter, the medullary canal diameter of isthmus(Di), the medullary canal diameter 10mm above the apex of the lesser trochanter(DT+10), the medullary canal diameter 20mm below the apex of the lesser trochanter(DT-20), and then DT+10/Di, DT-20/Di and DT+10/DT-20 were calculated. Results. There is no significant difference in neck-shaft angle between Crowe I-III DDH and the control group, while the neck-shaft angle is much smaller in Crowe IV DDH. The neck length of Crowe IV DDH is much smaller than those of Crowe I-III DDH. As for Di there is neither significant difference between Crowe I DDH and the control group, nor significant difference between CroweII-III and Crowe IV, but the difference is significant between the first two groups and the latter two groups. DT+10/DT-20 and the offset have no significant difference between the control group and DDH groups. DT-20, DT+10, DT+10/Di and DT-20/Di are much smaller in Crowe IV DDH than that in Crowe I-III and the control groups. Height of greater trochanter in Crowe IV is larger than those in Crowe I-III and the control group. Height of the centre of femoral head in Crowe IV DDH is smaller than those in Crowe I-III DDH and the control group. The height of the isthmus in Crowe IV is much smaller than those in Crowe I-III DDH and the control group. Conclusion. The neck-shaft angle in DDH groups is not larger than that in the control group, while in contrast, it's much smaller in Crowe IV DDH than that in the control group. Comparing to Crowe I-III DDH and the control group, Crowe IV DDH has a dramatic change in the intramedullary and extramedullary parameters. The isthmus and the great trochanter are higher and there is apparent narrowing of the medullary canal around the level of the lesser trochanter

Objectives. For patients with Developmental Dysplasia of the Hip (DDH) who progress to needing total joint arthroplasty it is important to understand the morphology of the femur when planning for and undertaking the surgery, as the surgery is often technically more challenging in patients with DDH on both the femoral and acetabular parts of the procedure. 1. The largest number of male DDH patients with degenerative joint disease previously assessed in a morphological study was 12. 2. In this computed tomography (CT) based morphological study we aimed to assess whether there were any differences in femoral morphology between male and female patients with developmental dysplasia undergoing total hip arthroplasty (THA) in a cohort of 49 male patients, matched to 49 female patients. Methods. This was a retrospective study of the pre-operative CT scans of all male patients with DDH who underwent THA at two hospitals in Japan between 2006–2017. Propensity score matching was used to match these patients with female patients in our database who had undergone THA during the same period, resulting in 49 male and 49 female patients being matched on age and Crowe classification. The femoral length, anteversion, neck-shaft angle, offset, canal-calcar ratio, canal flare index, lateral centre-edge angle, alpha angle and pelvic incidence were measured for each patient on their pre-operative CT scans. Results. Significant differences were found in femoral anteversion with a mean male anteversion of 22 ˚ (±14.2), compared to 30˚ (±15.5), in females (p=0.02, Confidence Interval (C.I.) 1.6 to 14.9, Figure 1), offset, with a mean male offset of 31 mm (±6.2), compared to 29 mm (±6.1) in females, (p=0.04, C.I: 0.2 to 4.8), and femoral length with a mean femoral length of 434 mm in males (±22.2), compared to 407 mm in females (±23.9), (p<0.001, C.I: 19.2 to 34.3, Figure 2). No significant differences between male and female patients were found for the other measurements. Discussion. This was the first study of this size assessing femoral morphology in male patients with DDH undergoing THA. Significant differences were found between male and female patients in femoral anteversion, length and offset. This should be taken into account when planning and performing THA in these patients. Based on the findings from this study, a more anteverted femoral neck can be expected at the time of surgery in a female patient with DDH undergoing total hip arthroplasty, compared to a male patient

Avascular necrosis (AVN) of the femoral head is a potentially devastating complication of treatment for developmental dysplasia of the hip (DDH). AVN most commonly occurs following operative management by closed (CR) or open reduction (OR). This occurrence has frequently been examined in single centre, retrospective studies, however, little high-level evidence exists to provide insight on potential risk factors. The purpose of this observational, prospective multi-centre study was to identify predictors of AVN following operatively-managed DDH. A multi-centre, prospective database of infants diagnosed with DDH from 0–18 months was analyzed for patients treated by CR and/or OR. At minimum one year follow-up, the incidence of AVN (Salter criteria) was determined from AP pelvis radiographs via blinded assessment and consensus discussion between three senior paediatric orthopaedic surgeons. Patient demographics, clinical exam findings and radiographic data were assessed for potential predictors of AVN. A total of 139 hips in 125 patients (102 female, 23 male) underwent CR/OR at a median age of 10.4 months (range 0.7–27.9). AVN was identified in 37 cases (26.6% incidence) at a median 23 months post-surgery. Univariate logistic regression analysis comparing AVN and no AVN groups identified sex, age at diagnosis, age at surgery, pre-surgery IHDI grade and time between diagnosis and surgery as potential predictive factors. Specifically, male sex (OR 2.21 [0.87,5.72]), IHDI grade IV, and older age at diagnosis (7.4 vs. 9.5 months) and surgery (10.2 vs. 13.6 months) were associated with development of AVN. Likewise, increased time between diagnosis and surgery (2.9 vs. 5.5 months) was also associated with a higher incidence. No association was found with surgery type (CR vs. OR), pre-surgery acetabular index or surgical hip. Development of AVN occurred in 26.6% of hips undergoing CR or OR at a median 23 months post-surgery. Male sex, older age at diagnosis and surgery, dislocation severity and increased time between diagnosis and surgery were associated with AVN. Longer-term follow-up and larger numbers will be required to confirm these findings. Early outcomes from this prospective patient cohort suggest that AVN is an important complication of operative management for DDH, and appears to occur at a comparable rate whether the reduction is performed open or closed. Male patients may be more susceptible to developing AVN and merits further exploration. Potential predictive factors of older age and length of time between diagnosis and surgery emphasize the importance of early detection and treatment to minimize complications and optimize outcomes

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

Introduction. Since 1989 we have been using custom lateral-flare stems. Using this stem, its lateral flare can produce high proximal fit and less fit in distal part. Applying this automatic designing software to the average femoral geometries, we can make off the shelf high proximal fit stem (Revelation ®). Putting the off the shelf stem, the original center of the femoral heads were well reproduced. But in DDH cases, severe deformities around hip sometimes make complicated difficulty for better functional reconstruction. They are high hip center such as Crowe II-IV, shortening of the femoral neck, high anteversion etc. DDH cases are well known to have higher anteversion than non DDH cases. There would be no definite explanations for it. The high anteversion would not always be harmful for the preoperative patients. But in some cases, osteophytes are observed at posterior side of the femoral head which make another sphere with different centre. We can guess that the patient's biomechanics had not been matched with the original anteversion. Then posterior osteophytes can correct inappropriate anteversion (self-reduction.) (Fig.1) In those patients, reduction of the anteversion by putting stems twisted into the canal or using modular stems are sometimes done by the surgeons' decision. Younger DDH cases can also be treated with THA, because of the complicated deformities or biomechanical disorders. Short stems are expected to reduce operative invasion and stress shielding then can reserve bone quality and quantity. From these point of view to improve the understanding of the characteristics of the DDH anteversion, and design a DDH oriented short stem could be one of good solution for those cases. Method. For the better understanding of the high anteversion 57 femora (mean anteversion: 34.4 deg.) were analyzed slice by slice. The direction of femoral head centre, lesser trochanter (LTR), linea aspera (aspera) just below LTR, aspera in the middle of the femur and aspera between the last 2 sections. All of the directions were assessed from PC line. To clarify the meaning of the head osteophytes, 35 operated cases were analyzed the extent of the head osteophytes. According to the results, a DDH oriented short stem was designed. Results. Even with the different anteversion, femoral head centres and LTRs were located within limited angle (51.4 +/−7.9 deg.) But aspera just below the LTR had no relation to the LTR direction, but always kept within limited angle (102.0 +/− 4.5) to the PC line. This means that DDH cases have proximal femurs of normal shape. But they are only twisted around the level just below the LTR. From this result, stems for DDH cases can have the same shape with normal stem inside the canal. The posterior osteophytes had reduced 4.6+/− 3.0 degree in average independently to the extent of anteversion. There was no tendency that higher anteversion cases have higher self-reduction angle. the stems were give the same shape inside the canal with stems for non DDH cases but its femoral head center was located with 5 degrees less anteversion

Background: Structural hip deformities including developmental dysplasia of the hip (DDH) and femoroacetabular impingement (FAI) are thought to predispose patients to degenerative joint changes. However, the natural history of these malformations is not clearly delineated. Methods: Seven-hundred twenty-two patients ≤55 years that received unilateral primary total hip arthroplasty (THA) from 1980–1989 were identified. Pre-operative radiographs were reviewed on the contralateral hip and only hips with Tönnis Grade 0 degenerative change that had minimum 10-year radiographic follow-up were included. Radiographic metrics in conjunction with the review of two experienced arthroplasty surgeons determined structural hip diagnosis as DDH, FAI, or normal morphology. Every available follow-up AP radiograph was reviewed to determine progression from Tönnis Grade 0–3 until the time of last follow-up or operative intervention with THA. Survivorship was analyzed by Kaplan-Meier methodology, hazard ratios, and multi-state modeling. Results: One-hundred sixty-two patients met all eligibility criteria with the following structural diagnoses: 48 DDH, 74 FAI, and 40 normal. Mean age at the time of study inclusion was 47 years (range 18–55), with 56% females. Mean follow-up was 20 years (range 10 – 35 years). Thirty-five patients eventually required THA: 16 (33.3%) DDH, 13 (17.6%) FAI, 6 (15.0%) normal. Kaplan-Meier analysis demonstrated that patients with DDH progressed most rapidly, followed by FAI, with normal hips progressing the slowest. The mean number of years spent in each Tönnis stage by structural morphology was as follows: Tönnis 0: DDH = 17.0 years, FAI = 14.8 years, normal = 22.9 years; Tönnis 1: DDH = 12.2 years, FAI = 13.3 years, normal = 17.5 years; Tönnis 2: DDH = 6.0 years, FAI = 9.7 years, normal = 8.6 years; Tönnis 3: DDH = 1.6 years, FAI = 2.6 years, normal = 0.2 years. Analysis of degenerative risk for categorical variables showed that patients with femoral head lateralization >10 mm, femoral head extrusion indices >0.25, acetabular depth-to-width index <0.38, lateral center-edge angle <25 degrees, and Tönnis angle >10 degrees all had a greater risk of progression from Tönnis 0 to Tönnis 3 or THA. Among patients with FAI morphology, femoral head extrusion indices >0.25, lateral center-edge angle <25 degrees, and Tönnis angle >10 degrees all increased the risk of early radiographic progression. Analysis of degenerative risk for continuous variables using smoothing splines showed that risk was increased for the following: femoral head lateralization >8 mm, femoral head extrusion index >0.20, acetabular depth-to-width index <0.30, lateral center-edge angle <25 degrees, and Tönnis angle >8 degrees. Conclusions: This study defines the long-term natural history of DDH and FAI in comparison to structurally normal young hips with a presumably similar initial prognostic risk (Tönnis Grade 0 degenerative change and contralateral primary THA). In general, the fastest rates of degenerative change were observed in patients with DDH. Furthermore, risk of progression based on morphology and current Tönnis stage were defined, creating a new prognostic guide for surgeons. Lastly, radiographic parameters were identified that predicted more rapid degenerative change, both in continuous and categorical fashions, subclassified by hip morphology

Introduction. Hip arthrodiastasis for paediatric hip conditions such as Perthes disease is growing in popularity. Intended merits include halting the collapse of the femoral head and maintaining sphericity by minimising the joint reaction force. This can also be applied to protecting hip reconstruction following treatment of hip dysplasia. Our aim was to assess functional outcomes and complications in a cohort of paediatric patients. Materials and Methods. A retrospective single-surgeon cohort study was performed in a University teaching hospital from 2018–2021. Follow-up was performed via telephone interview and review of patient records. Complications, time in frame and functional scores using the WOMAC hip score were recorded. Results. Following review, 26 procedures were identified in 24 patients. Indications included 16 cases of Perthes disease, 4 following slipper upper femoral epiphysis, 3 avascular necrosis, and single cases following infection, dysplasia and a bone cyst. Pre-treatment WOMAC scores averaged 53.9, improving to 88.5 post-removal. Pin site infections were encountered in 11 patients, all treated with oral antibiotics. Two patients required early removal of frame due to pin loosening. Average time in frame was 3.9 months. Conclusions. This series displays how hip arthrodiastasis can be used to manage paediatric hip conditions. Complex reconstructions may be required in patients with severe deformity following perthes disease, DDH or SUFE. The use of arthrodiastasis in these patients aims to protect the reconstruction and potentially improve outcomes. A dedicated team of specialist nurses, physiotherapists and psychologists are crucial to the treatment program