Aims. To describe the epidemiology of acetabular fractures including patient characteristics, injury mechanisms, fracture patterns, treatment, and mortality. Methods. We retrieved information from the Swedish Fracture Register (SFR) on all patients with acetabular fractures, of the native hip joint in the adult skeleton, sustained between 2014 and 2020. Study variables included patient age, sex, injury date, injury mechanism, fracture classification, treatment, and mortality. Results. In total, 2,132 patients with acetabular fractures from the SFR were included in the study. The majority of the patients were male (62%) and aged over 70 years old (62%). For patients aged > 70 years, the 30-day mortality was 8% and one-year mortality 24%. For patients aged ≤ 70 years, the 30-day mortality was 0.2% and one-year mortality 2%. Low-energy injuries (63%) and anterior wall fractures (20%) were most common. Treatment was most often non-surgical (75%). Conclusion. The majority of patients who sustain an acetabular fracture are elderly (> 70 years), of male sex, and the fracture most commonly occurs after a simple, low-energy fall. Non-surgical treatment is chosen in the majority of acetabular fracture patients. The one-year mortality for elderly patients with acetabular fracture is similar to the mortality after hip fracture, and a similar multidisciplinary approach to care for these patients should be considered. Cite this article: Bone Jt Open 2023;4(9):652–658

Aims. Periprosthetic hip-joint infection is a multifaceted and highly detrimental outcome for patients and clinicians. The incidence of prosthetic joint infection reported within two years of primary hip arthroplasty ranges from 0.8% to 2.1%. Costs of treatment are over five-times greater in people with periprosthetic hip joint infection than in those with no infection. Currently, there are no national evidence-based guidelines for treatment and management of this condition to guide clinical practice or to inform clinical study design. The aim of this study is to develop guidelines based on evidence from the six-year INFection and ORthopaedic Management (INFORM) research programme. Methods. We used a consensus process consisting of an evidence review to generate items for the guidelines and online consensus questionnaire and virtual face-to-face consensus meeting to draft the guidelines. Results. The consensus panel comprised 21 clinical experts in orthopaedics, primary care, rehabilitation, and healthcare commissioning. The final output from the consensus process was a 14-item guideline. The guidelines make recommendations regarding increased vigilance and monitoring of those at increased risk of infection; diagnosis including strategies to ensure the early recognition of prosthetic infection and referral to orthopaedic teams; treatment, including early use of DAIR and revision strategies; and postoperative management including appropriate physical and psychological support and antibiotic strategies. Conclusion. We believe the implementation of the INFORM guidelines will inform treatment protocols and clinical pathways to improve the treatment and management of periprosthetic hip infection. Cite this article: Bone Jt Open 2023;4(4):226–233

Surgical treatment of Hip PJI by resection of the infected implants and tissue and placement of a “spacer” which elutes antibiotic via antibiotic loaded cement is an accepted treatment option. There is some controversy over whether this “spacer” should be articulating or static. Proponents of the articulating option argue that there is improved function and maintenance of the soft tissue envelop. Critics have suggested that additional biomaterials may compromise eradication of infection. This study compares our results of the 2 treatment options. A review of our institutional PJI database between 2016 and 2021 identified 87 patients who were treated with resection arthroplasty for unilateral total hip PJI. The cohort was analyzed for demographics and type for surgery, as well as medical comorbidities, survivorship, and treatment success. 44 patients were female, the mean age of all patients was 62. 44 patients were treated with Articulating apacers, and 43 patients treated with static spacers. There was no significant difference between ASA or Elixhauser score, and no significant difference between mortality or treatment failure. This study did not show any difference between the patients who receive static spacers, from those who received articulating spacers, and deomstrated similar treatment success rates. From this data there does not appear to be any difference in success rates between those patients that were treated with static spacers and those that were treated with articulating spacers

There is a limited literature available describing the various diagnostic modalities and treatment options for the management of subspine impingement (SSI). We developed a study to evaluate the clinical improvement at 1 year and 5 years, with iHOT 33 and HOS hip scores. (1) Do patients with subspine compression improve with arthroscopic treatment clinically at short term follow-up (1 year)? (2) Is the improvement maintained in the mid-term (5 years)?. 43 young patients with subspine compression (prominent anterior inferior iliac spine) treated arthroscopically between January 2010 and December 2021 were included. Patients completed the iHOT33, HOS-SPORT and HOS-ADL questionnaires before surgery, 1 year and 5 years follow up. We evaluated pre and postoperative differences at one year and at 5 years. Minimum Clinically Significant Difference (MCID) and the Substantial Clinical Benefit (SCB) were used to stablish clinical improvement. Mean age was 37.38 years and 66% were males. Almost 75% and 70% of our patients exceed the MCID and the SCB respectively in all the questionnaires after 1 year-follow up. However, at 5 years-follow up, nearly 70% and 65% of the patients exceeded MCID and SCB respectively. We demonstrate that arthroscopic treatment of subspine impingement as an effective treatment for Subspine impingement. However, it is necessary larger sample size and longer follow up period to analyze the long-term results to demonstrate this treatment as the “gold standard”

Aims. Osteoporosis is common in total hip arthroplasty (THA) patients. It plays a substantial factor in the surgery’s outcome, and previous studies have revealed that pharmacological treatment for osteoporosis influences implant survival rate. The purpose of this study was to examine the prevalence of and treatment rates for osteoporosis prior to THA, and to explore differences in osteoporosis-related biomarkers between patients treated and untreated for osteoporosis. Methods. This single-centre retrospective study included 398 hip joints of patients who underwent THA. Using medical records, we examined preoperative bone mineral density measures of the hip and lumbar spine using dual energy X-ray absorptiometry (DXA) scans and the medications used to treat osteoporosis at the time of admission. We also assessed the following osteoporosis-related biomarkers: tartrate-resistant acid phosphatase 5b (TRACP-5b); total procollagen type 1 amino-terminal propeptide (total P1NP); intact parathyroid hormone; and homocysteine. Results. The prevalence of DXA-proven hip osteoporosis (T-score ≤ -2.5) among THA patients was 8.8% (35 of 398). The spinal osteoporosis prevalence rate was 4.5% (18 of 398), and 244 patients (61.3%; 244 of 398) had osteopenia (-2.5 < T-score ≤ -1) or osteoporosis of either the hip or spine. The rate of pharmacological osteoporosis treatment was 22.1% (88 of 398). TRACP-5b was significantly lower in the osteoporosis-treated group than in the untreated group (p < 0.001). Conclusion. Osteoporosis is common in patients undergoing THA, but the diagnosis and treatment for osteoporosis were insufficient. The lower TRACP-5b levels in the osteoporosis-treated group — that is, osteoclast suppression — may contribute to the reduction of the postoperative revision rate after THA. Cite this article: Bone Joint Res 2022;11(12):873–880

There is little known about how patient socioeconomic status impacts clinical outcomes in hip preservation surgery. The aim of this study was to evaluate the relationship between indices of multiple deprivation, funding provider (NHS Funded or Private Funded) and clinical outcomes following surgery for femoroacetabular impingement (FAI). The study analysed the data of 5590 patients recorded in the NAHR who underwent primary hip arthroscopic treatment for FAI between November 2013 and July 2023. Records were matched to the UK National index of multiple deprivation using the lower layer super output area. Using iHOT12 score, patient reported outcome measures were analysed at base line and 1 year following surgery. 2358 records were matched to LLSOA deciles. Between the lowest (most deprived) 3 deciles and the highest (least deprived) the average baseline iHOT12 score was 28.98 (n=366) and 35.33 (n=821). The proportion of patients receiving treatment through NHS funding compared to independent funding for the most deprived, 292 (90%) 37 (10%) respectively compared to the least deprived 515 (70%) and 244 (30%) respectively. At 1year, iHOT12 scores for each group were 51.64 (29.1 SD) compared to 61.5 (28.06 SD) respectively. The study demonstrates that patients from lower socioeconomic backgrounds had poorer baseline and one-year post-surgery iHOT12 scores compared to those from higher socioeconomic strata. Furthermore, a higher reliance on NHS funding was observed among the most deprived, while more affluent patients predominantly opted for private funding. These findings underscore the significant influence of socioeconomic status on both the quality of healthcare received and recovery outcomes in hip preservation surgery, calling attention to the need for more equitable healthcare solutions

Hip prosthetic joint infection (PJI) is a debilitating complication following joint replacement surgery, with significant impact on patients and healthcare systems. The INFection ORthopaedic Management: Evidence into Practice (INFORM:EP) study, builds upon the 6-year INFORM programme by developing evidence-based guidelines for the identification and management of hip PJI. A panel of 21 expert stakeholders collaborated to develop best practice guidelines based on evidence from INFORM \[1\]. An expert consensus process was used to refine guidelines using RAND/UCLA criteria. The guidelines were then implemented over a 12-month period through a Learning Collaborative of 24 healthcare professionals from 12 orthopaedic centres in England. Qualitative interviews were conducted with 17 members of the collaborative and findings used to inform the development of an implementation support toolkit. Patient and public involvement contextualised the implementation of the guidelines. The study is registered with the ISCRTN (34710385). The INFORM guidelines, structured around the stages of PJI management, were largely supported by surgeons, although barriers included limited awareness among non-surgical team members, lack of job planning for multidisciplinary teams, and challenges in ensuring timely referrals from primary care. Psychological support for patients was identified as a critical gap. Advanced Nurse Practitioners and multidisciplinary team (MDT) coordinators were seen as potential bridges to address these knowledge gaps. The guidelines were also viewed as a useful tool for service development. This study presents the first evidence-based guidelines for hip PJI management, offering a comprehensive approach to prevention, treatment, and postoperative care. Effective implementation is crucial, involving wider dissemination amongst primary and community care, as well as non-specialist treatment centres. Further resources are needed to ensure job planning for MDTs and psychological support for patients. Overall, this study lays the foundation for improved PJI management, benefiting patients and healthcare systems

Dual mobility (DM) components are increasingly used to prevent and treat dislocation after total hip arthroplasty (THA). Intraprosthetic dissociation (IPD) is a known rare complication of these implants and has reportedly decreased with modern implants. The purpose of this paper is to report the diagnosis and treatment of modern DM IPD. 1453 DM components were implanted between 2010 and 2021. 695 in primary and 758 in revision THA. 49 hips sustained a dislocation of the large head and 5 sustained an IPD at presentation. 6 additional IPD occurred at the time of reduction of large head. The average age was 64, 54% were female and the mean follow-up was three years. Of the 11 IPD, 8 had a history of instability, 5 had abductor insufficiency, 4 had prior lumbar fusion, and 3 were conversions from fracture. The overall IPD incidence was 0.76%. Ten of the 11 DM IPD were missed at initial presentation or at the time of reduction, and all were discharged with presumed reduction. The mean time from IPD to surgical treatment was 3 weeks. One patient died with an IPD at 5 months. A DM head was reimplanted in six, two underwent revision of the acetabular component with exchange of DM head, and four were revised to a constrained liner. The re-revision rate was 55% at a mean 1.8 years. None of the patients who underwent cup revision required subsequent re-revision while half of the constrained liners and exchange of DM heads required re-revision. The overall rate of DM dislocation or IPD is low. It is critical to identify an IPD on radiographs as it was almost universally missed at presentation or when it occurred iatrogenically. For patients presenting with IPD, the surgeon should consider acetabular revision and conversion to a constrained liner or a larger DM, with special attention to removing impinging structures that could increase the risk of re-dislocation

Displaced acetabular fractures in the older patient present significant treatment challenges. There is evidence the morbidity and mortality associated is similar to the fractured neck of femur cohort. Despite growing literature, there remains significant controversy regarding treatment algorithms; varying between conservative management, to fracture fixation and finally surgical fixation and simultaneous THA to allow immediate full weight bearing. £250k NIHR, Research for Patient Benefit (Ref: PB-PG-0815-20054). Trial ethical approval (17/EE/0271). After national consultation, 3 arms included; conservative management, fracture fixation and simultaneous fracture fixation with THA. Statistical analysis required minimum 12 patients/3 arms to show feasibility, with an optimum 20/arm. Inclusion criteria; patients >60 years & displaced acetabular fracture. Exclusion criteria: open fracture, THA in situ, pre-injury immobility, polytrauma. Primary outcome measure - ability recruit & EQ-5D-5L at 6 months. Secondary outcome measures (9 months); OHS, Disability Rating Index, radiographs, perioperative physiological variables including surgery duration, blood loss, complications and health economics. 11 UK level 1 major trauma centres enrolled into the trial, commenced December 2017. Failure surgical equipoise was identified as an issue regarding recruitment. Full trial recruitment (60 patients) achieved; 333 patients screened. 66% male, median age 76 (range 63–93), median BMI 25 (range 18–37), 87% full mental capacity, 77% admitted from own home. 75% fall from standing height. 60% fractures; anterior column posterior hemi-transverse. Trial feasibility confirmed December 2020. Presented data- secondary outcomes that are statistically significant in improvement from baseline for only the fix and replace arm, with acceptable trial complications. Issues are highlighted with conservative management in this patient cohort. Our unique RCT informs design and sample size calculation for a future RCT. It represents the first opportunity to understand the intricacies of these treatment modalities. This RCT provides clinicians with information on how best to provide management for this medically complex patient cohort

Femoroacetabular Impingement (FAI) syndrome, characterised by abnormal hip contact causing symptoms and osteoarthritis, is measured using the International Hip Outcome Tool (iHOT). This study uses machine learning to predict patient outcomes post-treatment for FAI, focusing on achieving a minimally clinically important difference (MCID) at 52 weeks. A retrospective analysis of 6133 patients from the NAHR who underwent hip arthroscopic treatment for FAI between November 2013 and March 2022 was conducted. MCID was defined as half a standard deviation (13.61) from the mean change in iHOT score at 12 months. SKLearn Maximum Absolute Scaler and Logistic Regression were applied to predict achieving MCID, using baseline and 6-month follow-up data. The model's performance was evaluated by accuracy, area under the curve, and recall, using pre-operative and up to 6-month postoperative variables. A total of 23.1% (1422) of patients completed both baseline and 1-year follow-up iHOT surveys. The best results were obtained using both pre and postoperative variables. The machine learning model achieved 88.1% balanced accuracy, 89.6% recall, and 92.3% AUC. Sensitivity was 83.7% and specificity 93.5%. Key variables determining outcomes included MCID achievement at 6 months, baseline iHOT score, 6-month iHOT scores for pain, and difficulty in walking or using stairs. The study confirmed the utility of machine learning in predicting long-term outcomes following arthroscopic treatment for FAI. MCID, based on the iHOT 12 tools, indicates meaningful clinical changes. Machine learning demonstrated high accuracy and recall in distinguishing between patients achieving MCID and those who did not. This approach could help early identification of patients at risk of not meeting the MCID threshold one year after treatment

Aims. The aim of this study was to compare the cost-effectiveness of cemented hemiarthroplasty (HA) versus hydroxyapatite-coated uncemented HA for the treatment of displaced intracapsular hip fractures in older adults. Methods. A within-trial economic evaluation was conducted based on data collected from the World Hip Trauma Evaluation 5 (WHiTE 5) multicentre randomized controlled trial in the UK. Resource use was measured over 12 months post-randomization using trial case report forms and participant-completed questionnaires. Cost-effectiveness was reported in terms of incremental cost per quality-adjusted life year (QALY) gained from the NHS and personal social service perspective. Methodological uncertainty was addressed using sensitivity analysis, while decision uncertainty was represented graphically using confidence ellipses and cost-effectiveness acceptability curves. Results. The base-case analysis showed that cemented implants were cost-saving (mean cost difference -£961 (95% confidence interval (CI) -£2,292 to £370)) and increased QALYs (mean QALY difference 0.010 (95% CI 0.002 to 0.017)) when compared to uncemented implants. The probability of the cemented implant being cost-effective approximated between 95% and 97% at alternative cost-effectiveness thresholds held by decision-makers, and its net monetary benefit was positive. The findings remained robust against all the pre-planned sensitivity analyses. Conclusion. This study shows that cemented HA is cost-effective compared with hydroxyapatite-coated uncemented HA in older adults with displaced intracapsular hip fractures. Cite this article: Bone Joint J 2022;104-B(8):922–928

Osteonecrosis of the femoral head after femoral neck fracture (ONFHpoFNFx) poses challenges in children, particularly at Ficat III stage. Limited effective treatments are available. This study explores basicervical femoral neck rotational osteotomy (BFNRO) for ONFHpoFNFx in children and adolescents and evaluates its outcomes. Children and adolescents with ONFHpoFNFx (Ficat stage III) underwent BFNRO at our center from June 2017 to September 2022 were included. Follow-up exceeded 1 year, with data on modified-Harris-hip-score (mHHS), range of motion (ROM), patient satisfaction, femoral head collapse, necrotic area repair, leg-length, and osteoarthritis progression recorded. This study included 15 cases (15 hips), with 8 males and 7 females, averaging 12.9 years in age (range: 10–17 years). Nine cases had BFNRO alone, and six had combined PAO. Rotation angles varied from 70° to 90° for anterior rotation and 110° to 135° for posterior rotation. Nine patients had femoral neck fixation in a varus position (10° to 30°). The postoperative contour of the weight-bearing area of the femoral head has significantly improved in all patients. With an average follow-up of 28.6 months (range: 12.2–72.7 months), mHHS significantly improved (65.2 to 90.2, P<0.001). Only one patient showed femoral head collapse. Patients experienced no/mild hip pain (VAS=0-3), slight restriction in range of motion, and mild limb shortening. Two patients showed osteoarthritis progression. No infections, joint replacements, or nerve injuries were observed. Even in cases of ONFHpoFNFx in the late stage, BFNRO in children and adolescents can still yield positive early to mid-term results by relocating the necrotic area and restoring the integrity of the anterior-lateral column of the femoral head, thereby preventing femoral head collapse and delaying the onset of severe osteoarthritis

The primary treatment goal for patients with femoroacetabular impingement syndrome, a common hip condition in athletes, is to improve pain and function. In selected patients, in the short term following intervention, arthroscopic hip surgery is superior to a pragmatic NHS- type physiotherapy programme. Here, we report the three-year follow-up results from the FemoroAcetabular Impingement Trial (FAIT), comparing arthroscopic hip surgery with physiotherapy in the management of patients with femoroacetabular impingement (FAI) syndrome. Two-group parallel, assessor-blinded, pragmatic randomised controlled study across seven NHS England sites. 222 participants aged 18 to 60 years with FAI syndrome confirmed clinically and radiologically were randomised (1:1) to receive arthroscopic hip surgery (n = 112) or physiotherapy and activity modification (n = 110). We previously reported on the hip outcome score at eight months. The primary outcome measure of this study was minimum Joint Space Width (mJSW) on Anteroposterior Radiograph at 38 months post randomisation. Secondary outcome measures included the Hip Outcome Score and Scoring Hip Osteoarthritis with MRI (SHOMRI) score. Minimum Joint Space Width data were available for 101 participants (45%) at 38 months post randomisation. Hip outcome score and MRI data were available for 77% and 62% of participants respectively. mJSW was higher in the arthroscopy group (mean (SD) 3.34mm (1.01)) compared to the physiotherapy group (2.99mm (1.33)) at 38 months, p=0.017, however this did not exceed the minimally clinically important difference of 0.48mm. SHOMRI score was significantly lower in the arthroscopy group (mean (SD) 9.22 (11.43)) compared to the physiotherapy group (22.76 (15.26)), p-value <0.001. Hip outcome score was higher in the arthroscopy group (mean (SD) 84.2 (17.4)) compared with the physiotherapy group (74.2 (21.9)), p-value < 0.001). Patients with FAI syndrome treated surgically may experience slowing of osteoarthritisprogression and superior pain and function compared with patients treated non- operatively

The aim of this study was to establish the natural course of unrevised asymptomatic pseudotumours after metal-on-metal (MoM) hip resurfacing during a six- to 12-month follow-up period. We used repeated metal artefact reduction sequence (MARS)-magnetic resonance imaging (MRI), serum metal ion analysis and clinical examination to study 14 unrevised hips (mean patient age 52.7 years, 46 to 68, 5 female, 7 male) with a pseudotumour and 23 hips (mean patient age 52.8 years, 38 to 69, 7 female, 16 male) without a pseudotumour. The mean post-operative time to the first MARS-MRI scan was 4.3 years (2.2 to 8.3), and mean time between the first and second MARS-MRI scan was eight months (6 to 12). At the second MRI scan, the grade of severity of the pseudotumour had not changed in 35 hips. One new pseudotumour (Anderson C2 score, moderate) was observed, and one pseudotumour was downgraded from C2 (moderate) to C1 (mild). In general, the characteristics of the pseudotumours hardly changed.

Repeated MARS-MRI scans within one year in patients with asymptomatic pseudotumours after MoM hip resurfacing showed little or no variation. In 23 patients without pseudotumour, one new asymptomatic pseudotumour was detected.

This is the first longitudinal study on the natural history of pseudotumours using MARS-MRI scans in hip resurfacing, and mirrors recent results for 28 mm diameter MoM total hip replacement.

Cite this article: Bone Joint J 2013;95-B:1626–31.

Aims

To clarify the mid-term results of transposition osteotomy of the acetabulum (TOA), a type of spherical periacetabular osteotomy, combined with structural allograft bone grafting for severe hip dysplasia.

Aims. Vancouver type B periprosthetic femoral fractures (PFF) are challenging complications after total hip arthroplasty (THA), and some treatment controversies remain. The objectives of this study were: to evaluate the short-to-mid-term clinical outcomes after treatment of Vancouver type B PFF and to compare postoperative outcome in subgroups according to classifications and treatments; to report the clinical outcomes after conservative treatment; and to identify risk factors for postoperative complications in Vancouver type B PFF. Methods. A total of 97 consecutive PPFs (49 males and 48 females) were included with a mean age of 66 years (standard deviation (SD) 14.9). Of these, 86 patients were treated with surgery and 11 were treated conservatively. All living patients had a minimum two-year follow-up. Patient demographics details, fracture healing, functional scores, and complications were assessed. Clinical outcomes between internal fixation and revisions in patients with or without a stable femoral component were compared. Conservatively treated PPFs were evaluated in terms of mortality and healing status. A logistic regression analysis was performed to identify risk factors for complications. Results. In surgically treated patients, all fractures united and nine complications were identified. The mean postoperative Visual Analogue Scale (VAS) for pain was 1.5 (SD 1.3), mean Parker Mobility Score (PMS) was 6.5 (SD 2.4), and mean Harris Hip Score (HHS) was 79.4 (SD 16.2). Among type B2 and type B3 fractures, patients treated with internal fixation had significantly lower PMS (p = 0.032) and required a longer time to heal (p = 0.012). In conservatively treated patients, one-year mortality rate was 36.4% (4/11), and two patients ultimately progressed to surgery. Young age (p = 0.039) was found to be the only risk factor for complications. Conclusion. The overall clinical outcome among Vancouver type B PFF was satisfactory. However, treatment with internal fixation in type B2 and B3 fractures had a significantly longer time to heal and lower mobility than revision cases. Conservative treatment was associated with high rates of early mortality and, in survivors, nonunion. This probably reflects our selection bias in undertaking surgical intervention. In our whole cohort, younger patient age was a risk factor for postoperative complications in Vancouver type B PFF. Cite this article: Bone Joint J 2020;102-B(3):293–300

Ganz's studies made it possible to address joint deformities on both femoral and acetabular side brought by the Legg-Calvè-Perthes disease (LCPD). Femoral head reduction osteotomy (FHRO) was developed to improve joint congruency along with periacetabular osteotomy (PAO). The purpose of this study is to show the clinical and morphologic outcomes of the technique, and an implemented planning approach.

From 2015 to 2023, 13 FHROs were performed on 11 patients for LCPD, in two centers. 11 of 13 hips had an associated PAO. A specific CT and MRI-based protocol for virtual simulation of the corrections was developed. Outcomes were assessed with radiographic parameters (sphericity index, extrusion index, integrity of the Shenton's line, LCE angle, Tonnis angle, CCD angle) and clinical parameters (ROM, VAS, Merle d'Aubigné-Postel score, modified-HHS, EQ5D-5L). Early and late complications were reported.

The mean follow-up was 40 months. The mean age at surgery was 11,4 years. No major complications were recorded. One patient required a total hip arthroplasty. Femoral Head Sphericity increased from 45% to 70% (p < 0,001); LCE angle from 18° to 42,8° (p < 0,001); extrusion Index from 36,6 to 8 (p < 0,001); Tonnis Angle from 14,4° to 6,2° (p = 0.1); CCD Angle from 131,7 to 136,5° (p < 0,023). The VAS score improved from 3,25 to 0,75,(p = 0.06); Merle d'Aubigné-Postel score from 14.75 to 16 (p = 0,1); Modified-HHS from 65,6 to 89,05 (p = 0,02). The EQ 5D 5L showed significant improvements. ROM increased especially in abduction and extra-rotation.

FHRO associated with periacetabular procedures is a safe technique that showed improved functional, clinical and morphologic outcomes in LCPD. The newly introduced simulation and planning algorithm may help to further refine the technique.

Aims

The aim of this study was to estimate the clinical and economic burden of dislocation following primary total hip arthroplasty (THA) in England.

This retrospective study was to investigate radiographic and clinical outcomes in treatment of hip instability in children and young adults undergoing periacetabular osteotomy (PAO) with or without femoral osteotomy. 19 patients (21 hips) with CP were treated with PAO with or without femoral osteotomy The mean age was 16.2 years old (7 to 28 years). Five patients (5 hips) received PAO, Six patients (7 hips) PAO with femoral derotation osteotomy, Eight patients (9 hips) PAO with varus derotational osteotomy (VDRO). Anteroposterior pelvic radiographs and CT were taken to assess the migration percentage (MP), lateral center-edge angle (LCEA), Sharp angle, femoral neck anteversion, neck-shaft angle. Gross Motor Function Classification System (GMFCS) was assessed pre- and post-surgery. Complications were recorded. The mean follow-up time was 41.2 months (range, 24 to 86 months). All hips but one were pain free at final visit. The GMFCS improved by one level in 10 of 19 patients. MP improved from a mean of 76.6% to 18.6% at the final follow-up(p<0.001). The mean pre-operative LCEA and Sharp angle were −33.5 ? and 35 ? respectively, improved to 21.5 ? and 11.8 ? at the final follow-up (p < 0.001). There were six patients (7 hips) had re-subluxation at latest follow-up. Nervus cutaneus femoris lateralis was impaired in four patients after surgery. There was no re-dislocation, AVN, or infections in this group. Satisfactory clinical and radiologic results can be obtained by PAO with or without femoral osteotomy minor complications

Introduction. Prosthetic joint infection (PJI) is an devastating complication after total hip arthroplasty (THA). The common treatment in the US is a two-stage exchange which can be associated with significant morbidity and mortality. The purpose of this study was to analyze complications in the treatment course of patients undergoing two-stage exchange for PJI THA and determine when they occur. Methods. We analyzed all patients that underwent two-stage exchange arthroplasty for treatment of PJI after THA from January 2005 – December 2017 at a single institution. Complications were categorized as medical or surgical, divided into three intervals: (1) inter-stage, (2) early post-reimplantation (<90 days) and (3) late post-reimplantation (> 90 days). Minimum follow up was one year. Success was based on the Musculoskeletal Infection Society (MSIS) definition. Results. 185 hips underwent first stage of planned two stage exchange. The median age was 65 (IQR 18). There were 93 males and 92 females. 73 patients had a complication during treatment. 13.5% (25/185) of patients experienced a medical complication and 28.1% (52/185) a surgical complication. There was a 14.1% (26/185) mortality at a median of 2.5 years (IQR 4.9). 51(29%) had complications during the interstage period, most common being recurrence of infection requiring a spacer exchange (48.6%). 2 patients died and 2 patients failed to progress to the second stage. 22(12%) complications following re-implantation, most commonly persistence /recurrence of infection (31%). 183/185 patients that initiated a two stage exchange were re-implanted, only 65% (120/185) were successfully treated with or without antibiotic suppression at one-year without additional surgery. Conclusions. While 2 stage exchanges for PJI in THA have been reported as successful, there are few reports of the complications during the process. In our series, significant numbers of patients experienced complications, often during the interstage period, highlighting the morbidity of this method of treatment