Experimental study on the biomechanical stability of complex acetabular fractures in the quadrilateral area: application of a dynamic anterior titanium-plate screw system.

BACKGROUND AND OBJECTIVE: Complex acetabular fractures involving quadrilateral areas are more challenging to treat during surgery. To date, there has been no ideal internal fixation for these acetabular fractures. The purpose of this study was to evaluate the biomechanical stability of complex acetabular fractures using a dynamic anterior titanium-plate screw system of the quadrilateral area (DAPSQ) by simulating the standing and sitting positions of pelvic specimens. MATERIALS AND METHODS: Eight formal in-preserved cadaveric pelvises aged 30-50 years were selected as the research objects. First, one hip of the normal pelvises was randomly used as the control model (group B) for measurement, and then one hip of the pelvises was randomly selected to make the fracture model in the 8 intact pelvises as the experimental model (group A) for measurement. In group A, acetabular both-column fractures in the quadrilateral area were established, and the fractures were fixed by DAPSQ. The biomechanical testing machine was used to load (simulated physiological load) from 400 N to 700 N at a 1 mm/min speed for 30 s in the vertical direction when the specimens were measured at random in simulated standing or sitting positions in groups. The horizontal displacement and longitudinal displacement of the acetabular fractures in the quadrilateral area were measured in both the standing and sitting simulations. RESULTS: As the load increased, no dislocation or internal fixation breakage occurred during the measurements. In the standing position, the horizontal displacement of the quadrilateral area fractures in group A and group B appeared to be less than 1 mm with loads ranging from 400 N to 700 N, and there was no significant difference between group A and group B (p > 0.05). The longitudinal displacement appeared to be greater than 1 mm with a load of 700 mm in group A (700 N, 2 cases), and the difference was significant between group A and group B (p < 0.05). In the sitting position, the horizontal and longitudinal displacements of the quadrilateral areas were within 0.5 mm in group A and group B, and there was no significant difference between group A and group B (p > 0.05). CONCLUSION: For complex acetabular fractures in the quadrilateral area, DAPSQ fixation may provide early sitting stability, but it is inappropriate for patients to stand too early.

Anterior Iliac Crest Bone Graft Harvest Using Acetabular Reamers.

VIDEO AVAILABLE AT: https://ota.org/education/ota-online-resources/video-library-procedures-techniques/anterior-iliac-crest-bone-0.

Robotic-assisted total hip arthroplasty utilizing a fluoroscopy-guided system produced similar cup accuracy and precision relative to a computerized tomography-based robotic platform.

Robotic assistance for total hip arthroplasty (THA) has been demonstrated to improve accuracy of acetabular cup placement relative to manual, unassisted technique. The purpose of this investigation was to compare the accuracy and precision between a fluoroscopy-based robotic total hip arthroplasty platform (FL-RTHA) and a computerized tomography-based (CT-RTHA) platform. The study included 98 consecutive FL-RTHA and 159 CT-RTHA procedures performed via direct anterior approach (DAA). All cases were performed for a pre-operative diagnosis of osteoarthritis, avascular necrosis, or rheumatoid arthritis. Primary outcome variables included cup implantation accuracy and precision (variance). Implantation accuracy was calculated as the absolute value of the difference between pre-operative target cup angles (inclination and anteversion) and the same post-operative angles. Percentage placement in the Lewinnek safe zone was also measured for both cohorts. The FL-RTHA and CT-RTHA cohorts demonstrated a 1.2° difference in absolute values for cup inclination accuracy (4.6° ± 3.6 vs. 3.4 ± 2.7; p = 0.005), and no difference in absolute values for cup anteversion accuracy (4.7° ± 4.1 vs. 4.6 ± 3.4; p = 0.991). Cohorts demonstrated similar precision for cup inclination and anteversion placement parameters, as well as equivalent Lewinnek safe zone placement. The use of a fluoroscopy-based robotic assistance platform for primary DAA THA resulted in similar accuracy and precision of acetabular cup placement when compared to a CT-based robotic assistance system.

Total hip arthroplasty with porous tantalum trabecular metal pads in patients with Crowe IV developmental dysplasia of the hip: a midterm followup study.

PURPOSE: Crowe IV developmental dysplasia of the hip (DDH) is a catastrophic hip disease. Moreover, obtaining ideal clinical efficacy in conventional total hip arthroplasty (THA) is often difficult. In this study, we aimed to assess the mid-term clinical results of THA with porous tantalum trabecular metal (TM) pads for acetabular reconstruction in the treatment of Crowe IV DDH. METHODS: A cohort of 28 patients (32 hips) diagnosed with Crowe type IV DDH who underwent acetabular reconstruction during THA using TM pads with scheduled follow-up between 2011 and 2018, were included in this study. Eight cases were men and 24 were women, with a mean age of 48.4 years (range, 36-72 years) and a mean follow-up was 74.3 months (range, 42-132 months). All patients underwent acetabular reconstruction using TM pads and total hip replacement with subtrochanteric osteotomy. RESULTS: At the final follow-up, 28 hips (87.5%) demonstrated mild or no postoperative limping. The Harris Hip Score improved from 58.4 ± 10.6 preoperatively to 85.6 ± 8.9. The mean pain, stiffness, and function scores on the Western Ontario and McMaster University Osteoarthritis index were 86.5 ± 10.2, 87.3 ± 12.4 and 85.4 ± 11.6 respectively. The mean score of patient satisfaction was 90.4 ± 7.6. Additionally, the SF-12 physical summary score was 41.8 ± 5.6 and the SF-12 mental summary score was 51.6 ± 5.4. TM construct survivorship due to all-cause failure was 90.6% at 5 years with 3 hips at risk, 87.5% at 10 years with 4 hips at risk. The survivorship due to failure from aseptic loosening was 96.9% at 5 years with 1hips at risk and 93.75% at 10 years with 2 hips at risk. CONCLUSION: This study demonstrated satisfactory mid-term clinical and radiological results with the application of TM pads for acetabular reconstruction combined with THA in patients with Crowe IV DDH. TRIAL REGISTRATION NUMBER: ChiCTR1800014526, Date: 18/01/2018.

The Principles of Hip Joint Preservation.

The 3 primary factors involved with preservation of the hip joint are femoroacetabular impingement (FAI), hip dysplasia, and femoral torsion abnormalities. Each of these factors affects the health of the acetabular labrum and femoroacetabular cartilage. The appropriate surgical treatments for each of these factors include arthroscopic or open femoroplasty or acetabuloplasty for FAI, periacetabular osteotomy (PAO) for acetabular dysplasia, and de-rotational femoral osteotomy for femoral torsion abnormalities. When evaluating patients with prearthritic hip conditions, orthopaedic surgeons should be aware of the various factors involved in hip joint preservation and, if surgery is indicated, surgeons should be sure to address all factors that need surgical treatment rather than focusing on the most obvious issue or injury (e.g., a labral tear). The purpose of this infographic is to illustrate the importance of the factors involved in hip joint preservation and the appropriate treatments for pathology in any of these factors.

Minimally invasive stabilization using screws and cement for acetabular metastatic tumor: a case report.

BACKGROUND: The aim of this case report is to evaluate minimally invasive stabilization using screws and cement for acetabular metastatic tumor and summarize the indications and contraindications for minimally invasive stabilization of acetabular metastatic tumors with screw and cement techniques. CASE PRESENTATION: Under imaging guidance, a patient with acetabular metastatic tumor was treated with hollow screw combined with bone cement fixation. Ischial screw, ascending branch screw, and anterior and posterior screws were inserted to firmly fix the anterior and posterior column of the acetabulum. At the same time, the third screw connected the anterior and posterior columns together, combined with bone cement into the fracture site to further increase local stability and resist bone defects caused by local tumor osteolysis. The patient was a 52-year-old Uygur male. Herein, we summarize his clinical symptoms and operation. Differences in visual analog scale and walking function (Musculoskeletal Tumor Society) before operation and at 2 months, 6 months, and 12 months after operation were compared. RESULTS: Postoperative complications and tumor progression were recorded. The patient was followed up for 16 months, and the operative time was 60 minutes. In total, 20 ml of bone cement was injected into the acetabular posterior column and the top of the acetabulum. VIsual analog scale score was 8 before operation, 3 at 2 months, 3 at 6 months, and 2 at 12 months after operation. Musculoskeletal Tumor Society function was 13 before operation, 23 at 2 months, 25 at 6 months, and 26 at 12 months after operation. During follow-up, no cement leakage, fever, hip nerve injury, pulmonary embolism, or imaging findings of further destruction of the acetabulum and surrounding bone were noted. CONCLUSION: This case report shows that the treatment of acetabular metastatic cancer with minimally invasive stabilization using screws and cement under the C arm can effectively relieve pain and enhance the strength of the pelvis, and is innovative and feasible.

Bibliometric analysis of the acetabular labrum.

The acetabular labrum (AL) plays a crucial role in the normal physiological functioning of the hip joint. This study aims to present an overview of the current status and research hotspots concerning the AL and to explore the field from a bibliometric perspective. A total of 1918 AL-related records published between January 1, 2000 and November 8, 2023 were gathered from the Web of Science Core Collection database. By utilizing tools such as HisCite, CiteSpace, VOSviewer, and the R package "bibliometrix," the regions, institutions, journals, authors, and keywords were analyzed to predict the latest trends in AL research. Global research interest and publication output related to this topic continues to escalate. The United States leads in international collaborations, number of publications, and citation frequency, underscoring its preeminent position in this field. The American Hip Institute emerged as the most prolific institution, making the greatest contribution to publications. Notably, Arthroscopy and the American Journal of Sports Medicine are the 2 most popular journals in this domain, accounting for 13.29% and 10.1% of publications, respectively, and were also found to be the most co-cited journals. Amongst authors, Benjamin G. Domb leads with 160 articles (8.35%), while Marc J. Philippon is the most frequently cited author. The keyword co-occurrence network showed 3 hot clusters, including "AL," "femoral acetabular impingement (FAI)," and "osteoarthritis." In addition, "survivorship," "FAI," and "patient-reported outcomes" were identified as trending topics for future exploration. This study represents the first comprehensive bibliometric analysis, summarizing the present state and future trends in AL research. The findings serve as a valuable resource for scholars, offering practical insights into key information within the field and identifying potential research frontiers and emerging directions in the near future.

Resolving residual acetabular dysplasia following successful brace treatment for developmental dysplasia of the hip in infants.

Aims: Radiological residual acetabular dysplasia (RAD) has been reported in up to 30% of children who had successful brace treatment of infant developmental dysplasia of the hip (DDH). Predicting those who will resolve and those who may need corrective surgery is important to optimize follow-up protocols. In this study we have aimed to identify the prevalence and predictors of RAD at two years and five years post-bracing. Methods: This was a single-centre, prospective longitudinal cohort study of infants with DDH managed using a published, standardized Pavlik harness protocol between January 2012 and December 2016. RAD was measured at two years' mean follow-up using acetabular index-lateral edge (AI-L) and acetabular index-sourcil (AI-S), and at five years using AI-L, AI-S, centre-edge angle (CEA), and acetabular depth ratio (ADR). Each hip was classified based on published normative values for normal, borderline (1 to 2 standard deviations (SDs)), or dysplastic (> 2 SDs) based on sex, age, and laterality. Results: Of 202 infants who completed the protocol, 181 (90%) had two and five years' follow-up radiographs. At two years, in 304 initially pathological hips, the prevalence of RAD (dysplastic) was 10% and RAD (borderline) was 30%. At five years, RAD (dysplastic) decreased to 1% to 3% and RAD (borderline) decreased to < 1% to 2%. On logistic regression, no variables were predictive of RAD at two years. Only AI-L at two years was predictive of RAD at five years (p < 0.001). If both hips were normal at two years' follow-up (n = 96), all remained normal at five years. In those with bilateral borderline hips at two years (n = 21), only two were borderline at five years, none were dysplastic. In those with either borderline-dysplastic or bilateral dysplasia at two years (n = 26), three (12%) were dysplastic at five years. Conclusion: The majority of patients with RAD at two years post-brace treatment, spontaneously resolved by five years. Therefore, children with normal radiographs at two years post-brace treatment can be discharged. Targeted follow-up for those with abnormal AI-L at two years will identify the few who may benefit from surgical correction at five years' follow-up.

Biomechanical Comparison of Fixation Methods for Posterior Wall Fractures of the Acetabulum: Conventional Reconstruction Plate vs. Spring Plate vs. Variable Angle Locking Compression Plate.

Background and Objectives: Acetabular fractures, though infrequent, present considerable challenges in treatment due to their association with high-energy trauma and poor prognoses. Posterior wall fractures, the most common type among them, typically have a more favorable prognosis compared to other types. Anatomical reduction and stable fixation of the posterior wall are crucial for optimal treatment outcomes. This study aimed to biomechanically compare three commonly used fixation methods for posterior wall fractures of the acetabulum-a conventional reconstruction plate, a spring plate, and a 2.7 mm variable angle locking compression plate (VA-LCP). Materials and Methods: The study utilized 6 fresh-frozen cadavers, yielding 12 hemipelvises free from prior trauma or surgery. Three fixation methods were compared using a simple acetabulum posterior wall fracture model. Fixation was performed by an orthopedic specialist, with prebending of plates to minimize errors. Hemipelvises were subjected to quasi-static and cyclic loading tests, measuring fracture gap, stiffness, and displacement under load. Results: It showed no significant differences in fracture gap among the three fixation methods under cyclic loading conditions simulating walking. However, the conventional reconstruction plate exhibited a greater stiffness compared to the spring and variable angle plates. Fatigue analysis revealed no significant differences among the plates, indicating a similar stability throughout cyclic loading. Despite differences in stiffness, all three fixation methods demonstrated adequate stability under loading conditions. Conclusions: While the conventional reconstruction plate demonstrated a superior stiffness, all three fixation methods provided sufficient stability under cyclic loading conditions similar to walking. This suggests that postoperative limitations are unlikely with any of the three methods, provided excessive activities are avoided. Furthermore, the variable angle plate-like the spring plate-offers an appropriate stability for fragment-specific fixation, supporting its use in surgical applications. These findings contribute to understanding the biomechanical performance of different fixation methods for acetabular fractures, facilitating improved surgical outcomes in challenging cases.

Developing a core outcome set for acetabular fractures: a systematic review protocol.

BACKGROUND: Clinical trials investigating acetabular fractures are heterogeneous in their investigated outcomes and their corresponding measurements. Standardization may facilitate comparability and pooling of research results, which would lead to an increase in knowledge about the optimal treatment of acetabular fractures, resulting in long-term evidence-based treatment decisions and improvements in patient care. The aim of this systematic review is to identify the reported outcomes and their measurements from studies on treatments for acetabular fractures to develop a core outcome set which contains the most relevant outcome measures to be included in future studies. METHODS: Studies published in English and German including patients aged 16 years and older, with a surgically treated acetabular fracture, will be included. Studies with nonsurgical treatment, pathologic fractures, polytraumatized patients, and patients younger than 16 years of age will be excluded because other outcomes may be of interest in these cases. Any prospective and retrospective study will be included. Systematic reviews will be excluded, but their included studies will be screened for eligibility. The literature will be searched on MEDLINE, CENTRAL, Web of Science, ClinicalTrials.gov, and WHO ICTRP. Risk of selective reporting of outcomes will be assessed using the Outcome Reporting Bias in Trials classification system. Heterogeneously defined outcomes that measure the same outcome will be grouped and subsequently categorized into outcome domains using the taxonomy of the Core Outcome Measures in Effectiveness Trials Initiative. DISCUSSION: It is expected that a high number of studies will be included, and many outcomes will be identified using different definitions and measurement instruments. A limitation of this systematic review is that only previously investigated outcomes will be detected, thus disregarding potentially relevant outcomes. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42022357644.

Antegrade anterior column acetabulum fracture fixation with cannulated compression headless screws-A biomechanical study on standardized osteoporotic artificial bone.

PURPOSE: Due to the increase in life expectancy and high-energy traumas, anterior column acetabular fractures (ACFs) are also increasing. While open reduction and internal fixation (ORIF) is still the standard surgical procedure, minimally invasive, percutaneous fixation of osteoporotic acetabulum fractures (AF) are growing in popularity. The aim of this biomechanical study was to evaluate the biomechanical competence following antegrade fixation with a standard screw versus a cannulated compression headless screw. METHODS: Eight anatomical osteoporotic composite pelvises were given an anterior column fracture. Two groups of eight specimens each (n = 8) for fixation with either a 6.5 mm cannulated compression headless screw in group Anterior Acetabulum Canulated Compression Headless Screw (AACCH), or with a 6.5 mm partially threaded cannulated screw in group Anterior Acetabulum Standard Screw (AASS) where compared. Each specimen was biomechanically loaded cyclically at a rate of 2 Hz with monotonically increasing compressive load until failure. Motions were assessed by means of optical motion tracking. RESULTS: Initial construct stiffness trended higher in group AACCH at 152.4 ± 23.1 N/mm compared to group AASS at 118.5 ± 34.3 N/mm, p = 0.051. Numbers of cycles and corresponding peak load at failure, were significantly higher in group AACCH at 6734 ± 1669 cycles and 873.4 ± 166.9 N versus group AASS at 4440 ± 2063 cycles and 644.0 ± 206.3 N, p = 0.041. Failure modes were breakout of the screws around the proximal entry point. CONCLUSION: From a biomechanical perspective, group AACCH was associated with superior biomechanical competence compared to standard partially threaded cannulated screws and could therefore be considered as valid alternative for fixation of anterior acetabulum fractures.

A new seven-axis robotic-assisted total hip arthroplasty system improves component positioning: a prospective, randomized, multicenter study.

This study compared the radiologic and clinical outcomes of a new seven-axis robotic-assisted total hip arthroplasty (THA) and conventional THA. Hundred and four patients were randomly assigned to two groups-the robotic-assisted THA group (RAS group) and the conventional THA group (CON group). The preoperative and postoperative Harris Hip score (HHS), acetabular inclination, anteversion, femoral offset, and leg length discrepancy (LLD) were compared. During the follow-up, no patients had any complications that could be associated with the use of the robot. The proportion of acetabular cups in the safety zone was significantly higher in the RAS group than that in the CON group. The two groups had significantly different mean absolute difference of inclination and anteversion. There was no significant difference in the postoperative HHSs, changes in HHSs, femoral offset, and lower limb length between the two groups. The seven-axis robotic-assisted THA system is safe and effective, and leads to better acetabulum cup positioning compared to conventional THA. The improvements observed in the HHS, LLD, and femoral offset in the RAS group were similar to those in the CON group.Clinical trial registration time: 19/05/2022.Clinical trial registration number: ChiCTR2200060115.

Peri-Operative Management of Periacetabular Osteotomy: A Report of Current Practices from the Anchor Group, Supporting Literature, and Areas for Future Investigation.

Background: Periacetabular osteotomy (PAO) is a well-established surgical treatment for hip dysplasia, but very few studies report the impact of peri-operative management strategies on early pain and function. The purpose of this study is to describe peri-operative management variability among a group of experienced surgeons and review the literature supporting these practice patterns. Methods: We surveyed 16 surgeons that perform PAO to document various aspects of peri-operative management at four stages: pre-operative, intra-operative, post-operative in the hospital, and at discharge. Our goal was to report current surgical pain management strategies, adjunct medications, type of anesthesia, deep venous thrombosis and heterotopic ossification prophylaxis strategies, initiation of physical therapy, and use of continuous passive motion (CPM). We reviewed current literature to identify studies supporting these perioperative strategies and identify knowledge gaps that would benefit from further investigation. Results: Of the 16 surgeons surveyed, 75% had been in practice greater than 10 years and most had not altered their post-operative protocol for more than 3 years. 15/16 surgeons felt that length of stay could be reduced at their institution with improved peri-operative pain management. 6/16 were considering or had already implemented outpatient PAO as a part of their practice. We found significant variability in the pain medications provided at all peri-operative stages. 14/16 utilized general anesthesia, and many utilized epidural or peripheral nerve blocks. 6/16 surgeons utilized surgical field block (also referred to as periarticular block). These surgeons advocated that surgical field block was an effective intervention with no/minimal complication risk. There is very little literature critically evaluating efficacy of these perioperative management strategies for PAO. Conclusion: There is significant practice variability in peri-operative management of PAO surgery. We report various strategies utilized by a group of experienced surgeons and review supporting literature. There are significant knowledge gaps in best surgical pain management strategies, adjunct medications, surgical field blocks, and use of CPM that need further investigation. Level of Evidence: IV.

Pain Management for Periacetabular Osteotomy: A Systematic Review.

Background: Early post-operative pain control is essential to facilitate rapid recovery after orthopaedic surgery. Despite periacetabular osteotomy (PAO) being the gold standard treatment of prearthritic hip dysplasia, there is limited evidence assessing efficacy of early post-operative pain management strategies. Recent literature has focused on non-opioid supplemental treatments such as nerve blocks or local wound infiltration. The purpose of this systematic review was to assess efficacy of these interventions to reduce pain, facilitate mobilization, reduce length of stay after PAO surgery. Methods: A systematic review was created under the guidance of PRISMA from databases that included PubMed, OVID Medline, Embase, SCOPUS, Cochrane Central Register of Clinical Trials, and clinicaltrials.gov from their creation dates to 12/21/23. These studies were screen based on predetermined inclusion and exclusion criteria. Results: A total of six studies were included in this analysis from independent institutions. Three investigated nerve blocks (fascia iliaca, pericapsular, transversus abdominis), one investigated local wound infiltration with ropivacaine, one investigated high-dose dexamethasone, and the last investigated removal of the epidural catheter on postoperative (POD) 1 compared to POD 2. There were heterogeneous outcomes that were measured from these studies. In general, nerve blocks decreased opioid use, pain, and length of hospital stay. The local wound infiltration decreased pain on POD 3 and 4. Removing the epidural catheter on POD1 compared to POD 2 decreased pain and length of stay. High-dose dexamethasone use decreased opioid use on POD 1, otherwise, there was no difference in pain. Conclusion: In summary, supplemental pain management strategies peri-operatively for PAO surgery can decrease pain, opioid use, and length of hospital stay, though there are few studies assessing these interventions. Limiting opioid use after surgery reduces known negative consequences of the medication and facilitates rapid recovery. Clinical trials are needed that assess efficacy of supplemental pain management strategies after PAO surgery. Level of Evidence: II.

Hip Dysplasia Treated With Periacetabular Osteotomy in Patients Over 40 Years Old: A Systematic Review.

Background: Hip dysplasia is a leading cause of hip osteoarthritis. While periacetabular osteotomy (PAO) is effective for relieving pain and dysfunction caused by hip dysplasia in adolescents and young adults, there is concern that patients over 40 years of age will have an increased risk of persistent dysfunction and need for total hip arthroplasty. Current available evidence for PAO in older adults is limited and there is no systematic review in the literature focusing on this topic. The current systematic review offers insight into the demographics, patient-reported outcome measure (PROM) scores, and hip survivorship from total hip arthroplasty in patients over 40 years older treated for hip dysplasia with PAO. Methods: The review was conducted under the guidelines for the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). Databases that were searched included PubMed, OVID Medline, SCOPUS, Embase, Cochrane Library, and clinicaltrials.gov. Studies were screened based on predetermined inclusion and exclusion criteria. Results: Five studies were included in this systematic review. Enrollment years were 1990-2013. In total, there were 335 hips with mean ages between 43.5-47.2 years. Mean follow up was 4-10.8 years. Most patients that underwent hip preservation had Tonnis osteoarthritis grade 0-1. There was contradicting evidence whether patients >40 years did better or worse compared to <40 years; although, most patients in the >40 years group had good outcomes after PAO. PAO survivorship ranged from 67-100% depending on the study. Complications ranged from 2-36% of cases depending on the study; although, none of these complications had lasting effects. Conclusion: Patients over 40 years old appear to have positive outcomes when treated for hip dysplasia with PAO, though these patients were likely selected for no to minimal osteoarthritis, high functional status, and good health. PAO should be considered for patients with hip dysplasia over 40 years old without hip arthritis, though we recommend very selective indications. Level of Evidence: II.

An exercise and patient education intervention to reduce pain and physical limitations in adults with acetabular dysplasia: study protocol for a process evaluation integrated within a randomised controlled trial (the MovetheHip trial).

BACKGROUND: The Movethehip trial investigates the effectiveness of an exercise and patient education intervention for adults with acetabular dysplasia. The intervention involves eight tailored one-to-one sessions with trained providers who employ supportive feedback tools. The present protocol reports a planned process evaluation, which aims to determine how the intervention functions by examining the implementation of the intervention (process, dose and reach), its acceptability, mechanisms of change and the influence of contextual factors. METHODS: Two hundred trial participants aged 18-50 years will be recruited from a University Hospital in Denmark and randomised to the intervention or control group. Approximately ten providers will deliver the intervention. The process evaluation adopts a concurrent mixed-methods design. The implementation will be assessed using self-report questionnaires (at baseline and 6-month follow-up), training records and semi-structured focus group interviews with intervention providers (n = 10) and healthcare managers (n = 4-6). The mechanisms of change will be explored through semi-structured one-to-one interviews (at baseline and 6-month follow-up) with 15-20 purposefully sampled participants and by measuring changes in health outcomes (self-reported pain, physical functioning and quality of life completed at baseline and at 3- and 6-month follow-up). Additionally, change will be measured through an explorative examination of associations between dose and change in health outcomes, applying simple linear regression models. The acceptability of the intervention and the influence of contextual factors will be explored through one-to-one participant interviews and focus group interviews with 4-6 healthcare managers. The interviews will focus on expectations, experiences, events, personal understandings and interaction with interpersonal and organisational aspects. Interview data will be analysed using theoretical thematic analyses, and findings will be merged with quantitative data and reported jointly on a theme-by-theme basis. DISCUSSION: The process evaluation conducted as part of the MovetheHip trial will illuminate how the intervention functions, and if the intervention is proven effective, the findings of the evaluation will contribute to pinpoint how the intervention may be optimised to facilitate future up-scaling and implementation. TRIAL REGISTRATION: The MovetheHip protocol was approved by the Committee on Health Research Ethics in the Central Denmark Region. ClinicalTrials, NCT04795843. Registered on 20 March 2021.

Total Hip Arthroplasty After Peri-Acetabular Osteotomy Results in Significant Improvement in Hip Function With Low Revision Rates at Mid-Term Follow-Up.

Background: Bernese periacetabular osteotomy (PAO) improves symptoms and delays degenerative changes in patients with acetabular dysplasia. Yet, eventual total hip arthroplasty (THA) is needed in many of these patients. The impact of PAO on subsequent THA outcomes is not well defined. The purpose of this study is to define: 1) clinical outcomes, 2) post-operative complications and 3) implant survivorship for patients undergoing THA after prior ipsilateral PAO. Methods: A retrospective review was conducted at three institutions to identify individuals undergoing THA after ipsilateral PAO surgery with minimum 1 year follow up. Patient reported outcome measures (PROMs) were collected preoperatively and at final follow-up. Surgical details, radiographic and clinical outcomes, and major complications according to the modified Dindo-Clavien classification system were identified through review of the medical record. Regression analysis and student's t-test were used to compare pre- and post-operative outcome scores. Kaplan-Meier analysis was performed to estimate reoperation-free survivorship. Results: A total of 113 THA in 112 patients were identified with initial review. 103 hips had a minimum of 1-year follow-up and an average follow of 5 ± 4 years (range, 1 to 20). 10 hips (9%) were lost to follow-up leaving 103 (91%) hips available for review with a minimum of 1-year follow-up (mean = 5 years). Mean interval from PAO to THA was 7.7 years (range, 2-15). The average post-operative mHHS improved 37 points (50 to 87, P < 0.001) when compared to pre-operative scores. Eight patients (7.1%) experienced a major grades III-V) surgical complication. These included 2 cases of instability, 2 cases of acetabular loosening, and one case each of periprosthetic fracture, wound dehiscence, periprosthetic infection, acetabular loosening and pneumonia. Failures occurred early at average 3.2 years and survivorship analysis for all-cause revision demonstrated 96% survivorship at both 5 and 10 years. Conclusion: THA after PAO achieves significant clinical improvement and satisfactory survivorship (96%) at mid-term follow-up, with a major complication rate of 7.1%. Level of Evidence: III.

Predictive Factors for Intraoperative Determination for the Need of Femoral Osteochondroplasty After Periacetabular Osteotomy for Acetabular Dysplasia.

Background: Determination of need for osteochondroplasty (OCP) during periacetabular osteotomy (PAO) commonly relies on intraoperative assessment of internal rotation at 90° flexion (IRF). Performing an OCP helps decrease the risk of iatrogenic femoroacetabular impingement from PAO reduction. Avoiding impingement helps decrease risks of accelerated secondary osteoarthritis. The literature is limited for factors that predict need for OCPs during PAOs. The purpose of this study was to (1) define the characteristics of patients needing concurrent OCP and provide OCP rate based on IRF and femoral version and (2) identify predictive factors (clinical, radiographic) associated with need for OCP during PAO. As some surgeons determine need for OCP pre-operatively, predictive factors would aid decision making. Methods: This was a prospective cohort of 224 hips (207 patients) who underwent PAO for symptomatic acetabular dysplasia, of which 154 hips (69%) underwent OCP between years 2013 and 2017. Patients underwent OCP if they had restrictions in motion or impingement intra-operatively. Pre-operative factors such as age, sex, BMI, and CT findings were recorded that underwent univariate and multivariable analyses. Multivariable analysis found predictors that were described using odds ratios and 95% confidence intervals. IRF>30° and femoral version 10°-25° were used as the reference groups during categorical analysis. P-values ≤0.05 were considered significant. Results: Alpha angles >55° (OR= 2.20, CI: 1.08-4.52, p= 0.03), IRF≤20° (OR: 9.52, CI: 3.87-23.40, p<0.001), IRF >20°-30° (OR: 2.68, CI: 1.08-6.62, p=0.03), and femoral version <10° (OR: 5.26, CI: 1.09-25.30, p=0.04) were associated with increased odds of OCP. On continuous modeling, decreasing femoral version (OR: 1.07, CI: 1.02-1.12, p=0.002) and IRF (OR: 1.06, CI: 1.03-1.09, p<0.001) were associated with increased chance of OCP. For 5° changes, the chance of OCP increased by 40% (OR: 1.40, CI: 1.13-1.73, p=0.002) and 35% (OR: 1.35, IC: 1.16-1.57, p<0.001), respectively. Conclusion: Awareness of need for OCP may be valuable in peri-operative planning for these patients especially since some surgeons perform this technique arthroscopically before PAO. Factors associated with increased chances of OCP were alpha angles >55°, decreased IRF, and decreased femoral version. More studies in the future would help determine how OCP affects patient outcomes. Level of Evidence: III.

[A clinical study of HoloSight Orthopaedic Trauma Surgery Robot-assisted infra-acetabular screw placement for acetabular fractures].

Objective: To investigate the effectiveness of HoloSight Orthopaedic Trauma Surgery Robot-assisted infra-acetabular screw placement for treatment of acetabular fractures. Methods: The clinical data of 23 patients with acetabular fractures treated with open reduction and internal fixation and infra-acetabular screw placement in two medical centers between June 2022 and October 2023 were retrospectively analyzed. According to the the method of infra-acetabular screw placement, the patients were divided into navigation group (10 cases, using HoloSight Orthopaedic Trauma Surgery Robot-assisted screw placement) and freehand group (13 cases, using traditional X-ray fluoroscopy to guide screw placement). There was no significant difference in gender, age, body mass index, cause of injury, time from injury to operation, and Judet-Letournel classification between the two groups ( P>0.05). The time of infra-acetabular screw placement, the fluoroscopy frequency, the guide pin adjustment times, the quality of screw placement, the quality of fracture reduction, and the function of hip joint were compared between the two groups. Results: All patients completed the operation successfully. The time of screw placement, the fluoroscopy frequency, and guide pin adjustment times in the navigation group were significantly less than those in the freehand group ( P<0.05). The quality of screw placement in the navigation group was significantly better than that in the freehand group ( P<0.05). Patients in both groups were followed up 6-11 months, with an average of 7.7 months. There were 9 and 9 cases in the navigation group and the freehand group who achieved excellent and good fracture reduction quality at 1 week after operation, and 12 and 12 cases with excellent and good hip joint function at last follow-up, respectively, and there was no significant difference between the two groups ( P>0.05). The fractures in both groups healed well, and there was no significant difference in healing time ( P>0.05). During the follow-up, there was no complication related to screw placement, such as failure of internal fixation, vascular and nerve injury, incisional hernia. Conclusion: In the treatment of acetabular fractures, compared with the traditional freehand screw placement, the HoloSight Orthopaedic Trauma Surgery Robot-assisted screw placement can reduce the time of screw placement, improve the accuracy of screw placement, and reduce the amount of radiation, which is an efficient, accurate, and safe surgical method.

3D-printed Personalized Porous Acetabular Component to Reconstruct Extensive Acetabular Bone Defects in Primary Hip Arthroplasty.

OBJECTIVE: Management of extensive acetabular bone defects in total hip arthroplasty (THA) remains challenging. This study aims to investigate the feasibility and preliminary outcomes of 3D-printed personalized porous acetabular components for the reconstruction of acetabular defects in primary THA. METHODS: This retrospective study involved seven patients who received 3D-printed acetabular components in primary THA between July 2018 and March 2021. Preoperatively, acetabular bone defects were evaluated by referencing the Paprosky classification. There were two "Paprosky type IIIA" defects and five "Paprosky type IIIB" defects. The acetabular components were custom-made for each patient to reconstruct the extensive acetabular defects. The hip function was assessed according to the Harris hip score (HHS). Clinical and radiographic outcomes were assessed. RESULTS: The average follow-up period was 40 months, ranging from 26 to 57 months. There were no patients lost to follow-up. The HHS improved from 44 (range: 33-53) before the operation to 88 (range: 79-93) at the final follow-up. Postoperative X-rays showed that the 3D-printed personalized components were properly fitted with the acetabulum. The average center of rotation (COR) discrepancy was 2.3 mm horizontally and 2.1 mm vertically, respectively. Tomosynthesis-Shimadzu metal artifact reduction technology images showed that the implant was in close contact with the host bone. Moreover, no complications were observed during the follow-up period, including loosening, dislocation, or component protrusion. CONCLUSION: The implantation of 3D-printed personalized acetabular components showed accurate reconstruction, stable mechanical support, and favorable function at short-term follow-up. This may be a viable alternative method for reconstructing extensive acetabular defects in THA.