Pelvic bone defect in patients with severe congenital dysplasia of the hip (CDH) lead to abnormalities in lumbar spine and lower limb alignment that can determine total hip arthroplasty (THA) patients' outcome. These variables may be different in uni- or bilateral CDH. We compared the clinical outcome and the spinopelvic and lower limb radiological changes over time in patients undergoing THA due to uni- or bilateral CHD at a minimum follow-up of five years. Sixty-four patients (77 hips) undergoing THA due to severe CDH between 2006 and 2015 were analyzed: Group 1 consisted of 51 patients with unilateral CDH, and group 2, 113 patients (26 hips) with bilateral CDH. There were 32 females in group 1 and 18 in group 2 (p=0.6). The mean age was 41.6 years in group 1 and 53.6 in group 2 (p<0.001). We compared the hip, spine and knee clinical outcomes. The radiological analysis included the postoperative hip reconstruction, and the evolution of the coronal and sagittal spinopelvic parameters assessing the pelvic obliquity (PO) and the sacro-femoro-pubic (SFP) angles, and the knee mechanical axis evaluating the tibio-femoral angle (TFA). At latest follow-up, the mean Harris Hip Score was 88.6 in group 1 and 90.7 in group 2 (p=0.025). Postoperative leg length discrepancy of more than 5 mm was more frequent in group 1 (p=0.028). Postoperative lumbar back pain was reported in 23.4% of the cases and knee pain in 20.8%, however, there were no differences between groups. One supracondylar femoral osteotomy and one total knee arthroplasty were required. The radiological reconstruction of the hip was similar in both groups. The PO angle improved more in group 1 (p=0.01) from the preoperative to 6-weeks postoperative and was constant at 5 years. The SFP angle improved in both groups but there were no differences between groups (p=0.5). 30 patients in group 1 showed a TFA less than 10º and 17 in group 2 (p=0.7). Although the clinical outcome was better in terms of hip function in patients with bilateral CDH than those with unilateral CDH, the improvement in low back and knee pain was similar. Patients with unilateral dysplasia showed a better correction of the PO after THA. All spinopelvic and knee alignment parameters were corrected and maintained over time in most cases five years after THA

Background. Total hip arthroplasty (THA) in patients with congenital dysplasia of the hip (CDH) is complex and challenging. The Crowe and Hartofilakidis classification systems are the most commonly used. However, neither encompasses the whole spectrum of disease and deformity and therefore does not guide modern surgical options. We present a new classification system which aims to guide surgical strategy by focusing on the three main areas of disease and deformity: Cup defect; De-rotation of femoral neck ante-version; Height of femoral subluxation. Each component is graded from 1–3 based on the severity of deformity and the potential surgical strategy required (with 3 being the most severe). A total numerical score will reflect the overall degree of difficulty which may be used when assessing surgical outcomes. The aim of this study is to assess the reliability of this new adult CDH classification system in the setting of THA. Study design and Methods. A sample size calculation showed 28 evaluations were required to reach a power of 85% (based on a kappa value of 0.4). The anterior-posterior pelvis and lateral hip radiographs of 30 hips, in 26 patients were evaluated by three Consultant Orthopaedic Surgeons using the classification detailed in table 1. A second evaluation, with the case order randomised, was performed after a minimum period of 1month. Randolph's free multi-rater Kappa co-efficient was used to assess for inter and intra- observer reliability and 95% confidence intervals were calculated. Results. The results of the Inter and intra–observer reliability for each classification component and for each rater respectively are shown in table 2 and 3. Conclusions. In comparison with other studies our reliability results were poorer when compared to the Hartofilakidis and Crowe classification systems. It was reported by the participants that our system enabled a more logical breakdown of the component deformities to address when performing THA in these hips. As with the Paprosky system for revision hip arthroplasty, this X-ray classification is intended as a practical pre-op guide to planning for all eventualities. Limitations due to level of observer experience and finer intra-operative judgements may alter the final result, but the essence is to understand the anatomical pitfalls enabling appropriate surgical planning and a total score against which to judge outcomes. For any figures or tables, please contact the authors directly

In primary total hip arthroplasty in patients affected by congenital dysplasia of the hip, stabilisation of the cup because of the altered shape of the acetabulum presents a problem. We have obviated this by creating a standard protocol with a press-fit classification that helps us to resolve such problems. In 269 cases (from 1994 to 2004) of patients affected by congenital dysplasia of the hip, we have always reconstructed the acetabulum using autologous bone grafts. After the right preparation of the acetabulum, when the cover of the metal back is complete and the stability is optimal (type I), bone grafts are not required (106 cases). After positioning of the cup, if we find defects that leave less than 30% of the external surface of the metal back uncovered but the stability is good (type II) (138 cases), we reconstruct such defects with small bone grafts (bone chips) captured by the femoral head of the patient. Greater bony defects that, after positioning of the metal back, do not allow an adequate stability and leave more than 30% of the cup (type III) uncovered (25 cases), we reconstruct the acetabulum with part of the femoral head fixed with screws. The follow-up at more than 5 years is between good and excellent (89–100) in all pateitns according to the Harris Hip Score

Background: A retroverted acetabulum has been hypothesized as a cause of osteoarthritis. This study was performed to evaluate whether radiographical cross-over sign influence the painful femoro-acetabular impingement or the radiographical progression of osteoarhritis after rotational acetabular osteotomy (RAO) for dysplastic hip. Methods: Between 1987 and 1999, 104 patients (115 hips) who had pre- or early stage osteoarthritis of the hip due to dysplasia underwent a RAO. There were 99 women and five men; their mean age at the time of surgery was 34.7 years. The mean follow-up period was 13 years. Clinical follow-up was performed with use of the system of Merle d’Aubigne and the impingement sign was evaluated. Radiographical analyses included measurements of the center-edge angle, acetabular roof angle, head lateralization index, joint congruency, cross-over sign, posterior wall sign, acetabular index of depth to width, pistol grip deformity and femoral head-femoral neck ratio. Results: The mean clinical score improved significantly from 14.6 preoperatively to 17.0 at follow-up. The impingement sign at the follow-up was observed in 14 hips (12.2%). The center-edge angle improved significantly from mean −0.6 degrees to a postoperative mean of 34 degrees. The acetabular roof angle improved from 30 degrees to 2.2 degrees, and head lateralization index from 0.64 to 0.60. The cross-over sign was observed in 8 hips (7.0%) preoperatively and in 49 hips (42.6%) postoperatively. The posterior wall sign was observed in 70 hips (60.9%) preoperatively and observed in 73 hips (63.5%) postoperatively. The mean preoperative acetabular index of depth to width was 35.5% and the mean preoperative femoral head to femoral neck ratio was 1.49. The pistol grip deformity was observed in only 4 hips (3.5%) preoperatively. The impingement sign after the RAO was positive significantly in the postoperative cross-over sign positive hips (p=0.0074). Radiographical progression of osteoarthritis was observed in 11 hips (cross over sign positive; 7 hips, cross over sign negative; 4 hips). The Kaplan-Meier survivorship analysis predicted a survival rate of 84.6 % at 15 years. The only factors significantly associated with radiographic signs of progression of osteoarthritis after RAO were fair (rather than excellent and good) postoperative joint congruency (p< 0.0001) and age at surgery (p=0.0042). Presence of postoperative cross-over sign had no effect on the outcome (p=0.2073). Conclusions: Although there was no significant radiographical progression of osteoarthritis despite a significant retroversion in most cases, the goal of RAO should be a correct alignment of the acetabulum including a correct version with a negative cross-over sign

The vertical configuration open MRI Scanner (Signa SPIO, General Electric) has been used to assess the place of interventional MR in the management of developmental dysplasia of the hip over the last four years. Twenty-six patients have been studied. In static mode, coronal and axial T1 – weighted spin echo images are initially obtained to assess the anatomy of the hip, followed by dynamic imaging in near-real time.

In all cases, dynamic imaging was very good for assessing and demonstrating stability. The best position for containment can be assessed and a hip spica applied. Scanning in two planes gives more information and allows more accurate positioning than an arthrogram. Confirmation of location of the hip after application of the spica can be easily demonstrated. Adductor tenotomies have been performed within the imaging volume, and in two cases, this enabled planning of femoral osteotomies. All patients have had a satisfactory outcome, but five have required open reduction and a Salter innominate osteotomy.

In ten cases, the opportunity has also arisen to alternative perform an arthrogram, either because of the complexity of the cases, or at a later date as an alternative to a repeat MRI, or because of difficulty with access to the machine.

The place of interventional MRI in DDH is not yet defined. As machines get better and the definition improves, the amount of information about the nature of dislocation, the relative size of the acetabulum to the femoral head, the state of the limbus, the best position for containment and stability, and the potential for growth of the acetabulum, particularly posteriorly will be increased.

It follows that the potential for more accurate definition of each hip and the outcome is better – and safer – than by arthrography, which remains the ‘gold standard’ but involves radiation and is only one-dimensional.

Background The ossific nucleus of the femoral head is usually present ultrasonographically around 12 weeks of age. It has been considered that the presence of an ossific nucleus in the femoral head is an indication of hip stability. In the ultrasound scan clinic for the assessment of developmental dysplasia of the hip at Sheffield Children’s Hospital, we have identified unstable hips with ossific nuclei, as well as, the appearance of ossific nuclei at as early as 2 weeks of age. These observations suggested the need to clarify the initial considerations that the ossific nucleus appeared ultrasonographically around 12 weeks of age and was an indicator of hip stability.

Aim To determine the relationship, if any, between the presence of the ossific nucleus of the femoral head ultrasonographically and stability of the hip.

Patient selection We have included in our study all the children who have had an ultrasound scan of their hips from 1996 to 1999 at Sheffield Children’s Hospital for suspected developmental dysplasia.

Methodology We have retrospectively reviewed reports of ultrasound scans performed for developmental dysplasia of the hip between 1996 and 1999. We have looked at the report for both the hips of each child. We have collected and analyzed data with regard to the age of the child at the time of the scan, the depth of the acetabulum, the shape of the femoral head, the presence or absence of an ossific nucleus, the dynamic stability of the hips and the congruity of the joint as reported on the ultrasound report. We report the findings in the first 318 hips of the 627 available patients in the study period.

Results The ossific nucleus can appear as early as 2 weeks and yet may not be visible until 24 weeks. In the 318 hips examined the ossific nucleus was present in 46 (14.47%). The age range for these scans was 1–40 weeks after birth. Of the 318 hips 252 (79.24%) were stable on dynamic screening, 274 (86.16%) had a normal(spherical) appearance of the femoral head, 209 (65.72%) had normal acetabular development and 263 (82.7%) demonstrated congruence of the hip joint. These data have been analyzed using Microsoft excel at confidence intervals of 0.8, which suggest no relationship between the presence of the ossific nucleus and hip stability.

Conclusion The limited early results of this study have shown that the ossific nucleus of the femoral head can appear from a very early age, may not appear until well after 12 weeks of age and is not an indicator of hip stability. Its presence on ultrasound scan does not exclude developmental dysplasia of the hip.

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

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

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

Introduction and Objectives: The aim of this study is to analyze changes seen on X-ray of the acetabular index, Wiberg’s angle, Sharp’s angle and the continuity of Shenton’s line after osteotomy performed by means of the Dega technique in developmental dysplasia of the hip (DDH). Materials and Methods: We retrospectively analyzed 72 histories of children that underwent surgery performed using the Dega technique at the Niño Jesús Hospital over the last 15 years. We measured the rupture of the Shenton line, the acetabular index, Wiberg’s centre-edge angle and Sharp’s acetabular angle preoperatively; and then approximately 1 year after surgery and at the last X-ray control in the medical history. Results: The acetabular index changed from 33° preoperatively to 24° one year after surgery. At the last X-ray control the acetabular index was 23°. Wiberg’s centre-edge angle is normalized by osteotomy, and changed from 6° preoperatively to 20° after surgery. At the last X-ray it was 23°. However, Sharp’s acetabular angle only suffered slight modifications. It changed from 50° to 48° with surgery. Discussion and Conclusions: The Dega osteotomy is an effective technique to provide acetabular coverage in hips suffering from dysplasia before the closure of the triradiate cartilage. Both the acetabular index and Wiberg’s angle vary significantly with surgery, and become normalized in most cases. This correction is stable over time. However, the same cannot be said for Sharp’s acetabular angle which barely changes with osteotomy

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.

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.

Introduction

Secondary osteoarthritis in a dysplastic hip is a surgical challenge. Severe leg length discrepancies and torsional deformities add to the problem of inadequate bony support available for the socket. Furthermore, many of these patients are young and wish to remain active, thereby jeopardising the long-term survival of any arthroplasty device.

For such severely dysplastic hips, the Birmingham Hip Resurfacing (BHR) device provides the option of a dysplasia component, a hydroxyapatite-coated porous uncemented socket with two lugs to engage neutralisation screws for supplementary fixation into the solid bone of the ilium more medially. The gap between the superolateral surface of the socket component and the false acetabulum is filled with impacted bone graft.

Nowadays navigation system for THA is widespread and contributes to accurate cup installation as for cup abduction and anteversion angles. On the other hand, cup center position is very important to prevent leg length discrepancy and to acquire appropriate muscle tension especially for DDH cases. However planning and accuracy of cup center position was rarely mentioned when the efficacy of navigation systems were discussed. We therefore examined not only accuracy of cup angles, but also of cup center position in our image-free navigation system for DDH.

One hundred three THA operations were performed with using the image-free OrthoPilot hip navigation system (B. Braun Aesculap, Tuttlingen, Germany) between May 2006 and July 2008 by three experienced surgeons. In this system, we can measure the length between two different points marked by special pointer during surgery. Thus we pointed the upper rim of obturator foramen (this mark was estimated the lower tip of tear drop, and the bottom of reaming hole (this mark was estimated same height from cup center position) before cup installation and measured the vertical length between them(op length). After operation, we measured the vertical length from tear drop to cup center on the x-ray film (xp length), and compared these two values.

The average difference of two values were 6.41±4.17 mm ((op length)-(xp length)). Secondly we divided them into two groups, large error group (> 0.7mm) and small error group (< 0.6mm) and investigated the cause of large error. As result, large error was influenced by difference of surgeons, whereas not influenced by patient’s etiology and BMI.

By using image-free navigation system for DDH, we can plan the cup center position and install it within the error of 6.4mm. This will contribute to avoid a lot of hesitations during surgery. However surgeon’s skill and habitants have influence on this technique. We have to investigate this system and make effort to further improvement continuously.

Aims. Although there are various pelvic osteotomies for acetabular dysplasia of the hip, shelf operations offer effective and minimally invasive osteotomy. Our study aimed to assess outcomes following modified Spitzy shelf acetabuloplasty. Methods. Between November 2000 and December 2016, we retrospectively evaluated 144 consecutive hip procedures in 122 patients a minimum of five years after undergoing modified Spitzy shelf acetabuloplasty for acetabular dysplasia including osteoarthritis (OA). Our follow-up rate was 92%. The mean age at time of surgery was 37 years (13 to 58), with a mean follow-up of 11 years (5 to 21). Advanced OA (Tönnis grade ≥ 2) was present preoperatively in 16 hips (11%). The preoperative lateral centre-edge angle ranged from -28° to 25°. Survival was determined by Kaplan-Meier analysis, using conversions to total hip arthroplasty as the endpoint. Risk factors for joint space narrowing less than 2 mm were analyzed using a Cox proportional hazards model. Results. The mean Merle d'Aubigné clinical score improved from 11.6 points (6 to 17) preoperatively to 15.9 points (12 to 18) at the last follow-up. The survival rates were 95% (95% confidence interval (CI) 91 to 99) and 86% (95% CI 50 to 97) at ten and 15 years. Multivariate Cox regression identified three factors associated with radiological OA progression: age (hazard ratio (HR) 2.85, 95% CI 1.05 to 7.76; p = 0.0398), preoperative joint space (HR 2.41, 95% CI 1.35 to 4.29; p = 0.0029), and preoperative OA (HR 8.34, 95% CI 0.94 to 73.77; p = 0.0466). Conclusion. Modified Spitzy shelf acetabuloplasty is an effective joint-preserving surgery with a wide range of potential indications. Cite this article: Bone Jt Open 2023;4(12):932–941

MCID and PASS are thresholds driven from PROMS to reflect clinical effectiveness. Statistical significance can be derived from a change in PROMS, whereas MCID and PASS reflect clinical significance. Its role has been increasingly used in the world of young adult hip surgery with several publications determining the thresholds for Femoro-acetabular impingement FAI. To our knowledge MCID and PASS for patient undergoing PAO for dysplasia has not been reported. 593 PAOs between 1/2013 and 7/2023 were extracted from the Northumbria Hip Preservation Registry. Patients with available PROMS at 1year and/or 2years were included. PAOs for retroversion, residual Perthes and those combined with FO were excluded. MCID was calculated using the distribution method 0.5SD of baseline score(1). PASS was calculated using anchor method, ROC analysis performed, and value picked maximizing Youden index. A Logistic Regression analysis was performed to determine which independent variables correlated with achieving MCID and PASS. The MCID threshold for iHOt12 was 8.6 with 83.4 and 86.3 % of patients achieved it at 1 and 2 years respectively. The PASS score at 1 and 2 year follow up was 43 and 44 respectively, with 72.6 and 75.2% achieving it at 1 and 2 year postop. At 2 years a Higher preop iHOT 12 was associated with not achieving MCID and PASS (p<0.05). Preop acetabular version was negatively correlated with achieving MCID and previous hip arthroscopy was negatively correlated with PASS. The % of patients achieving MCID and PASS mimics that of FAI surgery (2). The negative correlation with preop iHOT12 reaffirms the importance of patient selection. The negative correlation of hip arthroscopy highlights the importance of having a high index of suspicion for dysplasia prior to hip arthroscopy and poorer outcomes of patients with mixed CAM and dysplasia pathology

Developmental dysplasia of the hip can cause pain and premature osteoarthritis. However, the risk factors and timing for disease progression in young adults are not fully defined. This study identified the incidence and risk factors for contralateral hip pain and surgery after periacetabular osteotomy (PAO) on an index dysplastic hip. Patients followed for 2+ years after unilateral PAO were grouped by eventual contralateral pain or no-pain, based on modified Harris Hip Score, and surgery or no-surgery. Univariate analysis tested group differences in demographics, radiographic measures, and range-of-motion. Kaplan-Meier survival analysis assessed pain development and contralateral hip surgery over time. Multivariate regression identified pain and surgery risk factors. Pain and surgery predictors were further analyzed in Dysplastic, Borderline, and Non-dysplastic subcategories, and in five-degree increments of lateral center edge angle (LCEA) and acetabular inclination (AI). 184 patients were followed for 4.6±1.6 years, during which 51% (93/184) reported hip pain and 33% (60/184) underwent contralateral surgery. Kaplan-Meier analysis predicted 5-year survivorship of 49% for pain development and 66% for contralateral surgery. Painful hips exhibited more severe dysplasia than no-pain hips (LCEA 16.5º vs 20.3º, p<0.001; AI 13.2º vs 10.0º p<0.001). AI was the sole predictor of pain, with every 1° AI increase raising the risk by 11%. Surgical hips also had more severe dysplasia (LCEA 14.9º vs 20.0º, p<0.001; AI 14.7º vs 10.2º p<0.001) and were younger (21.6 vs 24.1 years, p=0.022). AI and a maximum alpha angle ≥55° predicted contralateral surgery. 5 years after index hip PAO, 51% of contralateral hips experience pain and 34% percent are expected to need surgery. More severe dysplasia, based on LCEA and AI, increases the risk of contralateral hip pain and surgery, with AI being a predictor of both outcomes. Knowing these risks can inform patient counseling and treatment planning

The periacetabular osteotomy(PAO) is an effective common hip-preserving procedure to treat symptomatic acetabular dysplasia of the hip (DDH). The literature regarding truly long-term patient outcomes after PAO remains limited. We sought to evaluate our patient cohort treated by PAO 25 to 33 years ago to identify factors positively and negatively associated with durable therapeutic success. 219 dysplastic hips (183 patients) underwent PAO between August 1991 and December 1999 by a single surgeon. 164 hips in 134 patients were retrospectively evaluated at minimum of 25 years and maximum of 33 years post-operatively. Hips were evaluated using the pain subscale of the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) postoperatively. Osteotomy failure was defined as WOMAC pain score of >/=10 or the need for total hip arthroplasty (THA). 7 patients (7 hips) had died - none of whom had THR. 142/176 remaining patients were located. All patients returned questionnaires; some were seen in person with images. Of patients analyzed to date, 109 hips (63%) were asymptomatic/mildly symptomatic with a preserved hip. 58 hips (33%) had undergone THA. 7 preserved hips (5%) were symptomatic (WOMAC>10). Patients with THA were slightly older than asymptomatic patients (54 ± 8 years vs. 50 ± 11 years; p=0.08), as they had been at time of PAO. Most patients were female (83%), with 89% of hip replacement patients being female. 4/58 replaced hips had been revised - 3 for instability and 1 for acetabular loosening. Data collection is ongoing as more patients are located and reviewed. Long-term follow-up of patients is challenging. Review after minimum of 25 years of the Boston cohort treated with PAO after minimum of 25 years dysplasia reveals that most at long-term follow-up report high levels of function, whether or not they had required arthroplasty, although 33% had required interim treatment with THA

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

In this study, we evaluated the labrum tear using radial sequence 3D Multiple Echo Recombined Gradient Echo (MERGE) MRI without arthrography based on modified Czerny's classification, comparing with actual arthroscopic findings. A total of 61 hips including 27 hips of femoroacetabular impingement (FAI), 19 hips of borderline development dysplasia of the hip (BDDH) and 15 hips of early stage osteoarthritis (OA) were enrolled this retrospective study. MRI findings evaluated in each three regions of interest; anterior region, anterolateral region, and lateral region. The cases with severe degeneration that is not concordant with any original Czerny's classification is defined as stage4. We compared MRI findings with arthroscopic findings and calculated the sensitivity, specificity, and likelihood ratio in terms of the existence of labrum tear. MRI findings revealed labrum tear more frequently in anterolateral than lateral (p<0.001). Especially in FAI group, labrum tear was more frequently observed by MRI in anterolateral than lateral (p=0.006). In comparison with MRI findings and arthroscopic findings, the sensitivity was 97%, specificity was 79% and likelihood ratio was 4.59 as average of all regions in terms of the existence of labrum tear. In each region, sensitivity and specificity was 97% and 50% in anterior, 97% and 100% specificity in anterolateral, 94% and 81% in lateral, respectively. Thus, MERGE MRI revealed excellent sensitivity and specificity for diagnosis of labrum tear, especially in anterolateral region. The cases with severely degenerated labrum were classified as newly defined stage 4, which was recognized frequently in OA cases