Acetabular Wall Research Articles

Novel implant design for comminuted posterior wall acetabular fractures.

In recent years, the medical community has witnessed a notable increase in high-energy traumatic injuries, leading to a surge in complex fracture patterns that challenge existing treatment methodologies. Among these, the posterior approach to acetabular fractures stands out for offering direct visualization of the retro-acetabular surface, with current fixation methods relying on 3.5mm low-profile reconstruction plates and various other implants. Despite the effectiveness of these methods, there is a burgeoning demand for a singular, adaptable implant that not only streamlines the surgical process but also optimizes patient outcomes. In an innovative approach to address this need, three-dimensional (3D) models of the posterior acetabular wall were meticulously crafted using AutoCAD® software. The chosen material for the implant was 316L surgical steel for its durability and strength. The design of the implant featured a low-profile mesh structure, which was instrumental in facilitating osteosynthesis. This design allowed for the placement of screws of varying lengths in multiple directions, ensuring the initial reconstruction of the joint in an anatomical position without hindering the placement of the definitive implant. The primary objective was to secure the fixation and stabilization of the fracture by specifically targeting the smaller bone fragments. A comparative analysis was then conducted between this novel plate and a conventional 316L surgical steel, seven-hole, 3.5mm reconstruction plate through finite element analysis. The comparative analysis unveiled that both plates demonstrated comparable deformation capacities, with no significant differences in load-bearing capabilities observed. This finding suggests that the innovative plate can match the performance of traditional plates used in such surgeries. The finite element analysis revealed that the newly developed anatomical plate for posterior wall acetabular fractures meets the necessary physical and mechanical criteria for permanent implementation in patients with these fractures. This breakthrough represents a promising advancement that could simplify surgical procedures and potentially elevate patient outcomes. This study is classified as a Level II, diagnostic study.

Acetabular morphology variations in a Hispanic population.

Rotational abnormalities of the hip have been implicated in the etiology of diseases, such as hip dysplasia, osteoarthritis, and femoroacetabular impingement. Despite the extensive literature on hip morphology, there is a gap in knowledge regarding variations in the Hispanic population. To describe the bony anatomy variations of the acetabulum in a Hispanic population. This is a cross-sectional study. We studied 182 computed tomography (CT) images in patients aged older than 21 years, who had undergone pelvic CT for any condition, except hip fracture. Measurements of acetabular version, anterior and posterior acetabular sector angles (AASA/PASA) and horizontal acetabular sector angles (HASA) were made. Acetabular variations were then compared to weight and sex data. The mean acetabular anteversion was greater in women (P < 0.001). Women exhibited a greater PASA (P < 0.05); however, men had a greater AASA (P < 0.05). Underweight individuals had a smaller PASA (P < 0.01) and HASA (P < 0.05) than individuals with a normal weight. The Hispanic hip is morphologically similar to other populations previously reported in the literature; however, Hispanic men have less coverage of the femoral head by the posterior acetabular wall when compared to women of the same ethnicity. These abnormalities have a direct impact on management and surgical approach in patients treated for femoroacetabular impingement and hip dysplasia.

Anatomical Posterior Acetabular Plate Versus Conventional Reconstruction Plates for Acetabular Posterior Wall Fractures: A Comparative Study.

Background: Functional recovery following the surgical fixation of acetabular posterior wall fractures remains a challenge. This study compares outcomes of posterior wall fracture reconstruction using an anatomical posterior acetabular plate (APAP) versus conventional reconstruction plates. Methods: Forty patients with acetabular fractures involving the posterior wall or column underwent surgery, with 20 treated using APAPs (APAP group) and 20 with conventional pelvic reconstruction plates (control group). Baseline patient characteristics, intraoperative blood loss and time, reduction quality, postoperative function, and postoperative complications were compared using appropriate non-parametric statistical tests. A general linear model for repeated measures analysis of variance was employed to analyze trends in functional recovery. Results: No significant differences were observed in baseline characteristics. APAP significantly reduced surgical time by 40 min (186.5 ± 51.0 versus 225.0 ± 47.7, p =0.004) and blood loss (695 ± 393 versus 930 ± 609, p = 0.049) compared to conventional plates. At 3 and 6 months following surgery, the APAP group exhibited higher functional scores (modified Merle d'Aubigné scores 10 ± 1.8 versus 7.8 ± 1.4, p < 0.001; 13.4 ± 2.8 versus 10.1 ± 2.1, p = 0.001), converging with the control group by 12 months (modified Merle d'Aubigné scores 14.2 ± 2.6 versus 12.7 ± 2.6, p = 0.072; OHS 31.6 ± 12.3 versus 30.3 ± 10.1, p = 0.398). Radiologically, the APAP group demonstrated superior outcomes (p = 0.047). Complication and conversion rates to hip arthroplasty did not significantly differ between groups (10% versus 15%, p = 0.633). Conclusions: The use of an APAP in reconstructing the posterior acetabulum significantly reduces surgical time, decreases intraoperative blood loss, and leads to earlier functional recovery compared to conventional reconstruction plates. The APAP provides stable fixation of the posterior wall and ensures the durable maintenance of reduction, ultimately yielding favorable surgical outcomes.

Comparison of the posterior hemipelvectomy of the greater trochanter approach with the standard Kocher-Langenbeck approach in the treatment of posterior acetabulum wall fractures

To compare the clinical efficacy of the posterior hemipelvectomy of the greater trochanter approach with the standard Kocher-Langenbeck(K-L) approach in the treatment of posterior acetabulum wall fractures and to explore a more optimal approach for the treatment of posterior acetabulum wall fractures. Total of 26 patients with posterior acetabulum wall fractures were retrospectively analysed and divided into two groups:the posterior hemipelvectomy of the greater trochanter group (test group) and the standard K-L approach group (control group). In the test group, there were 24 patients including 16 males and 8 females with an average age of (42.00±4.52) years old, the time of injury to surgery was (6.75±1.15) d. In the control group, there were 23 patients including 16 males and 7 females with an average age of (41.00±5.82) years old, the time of injury to surgery was (7.09±1.20) days. The total hospital stay, length of incision, operation time, intraoperative bleeding, postoperative drainage, discharge, fracture reduction quality (Matta criteria), hip abduction muscle strength, hip function (Merle d'Aubigne-Postel score), postoperative complications and the incidence of ectopic ossification were compared. All cases were followed up for 6 months. There was no significant difference in incision length, intraoperative bleeding and postoperative drainage between two groups(P>0.05). However, the operation time of the test group was shorter than that of the control group (P<0.05). There was no statistically significant difference in fracture reduction and hip function between two groups (P>0.05). The hip abduction muscle strength of test group was better than that of control group(P<0.05). In addition, there was no significant difference in the incidence of postoperative complications and heterotopic ossification between two groups(P>0.05). Compared with the standard K-L approach, the posterior hemipelvectomy of the greater trochanter approach can shorten the operative time, has better recovery of the postoperative hip abduction muscle strength, exposes the view of the fracture involving the more comminuted posterior acetabulum wall or the fracture of the roof of the socket, improved the rate of fracture anatomical repositioning, provides a new idea for the clinical treatment of posterior acetabulum wall fractures, and allows patients to perform functional exercises at an early stage.

Analysis of the therapeutic effect of trochanteric flip osteotomy combined with Kocher-Langenbeck approach for high acetabular posterior wall fracture

Evaluation of the clinical efficacy of f trochanteric flip osteotomy combined with Kocher-Langenbeck approach for high acetabular posterior wall fracture. Between January 2020 and December 2022, 20 patients with high acetabular posterior wall fractures were retrospectively analyzed, including 12 males and 8 females, aged 18 to 75 years old. They were divided into two groups according to the different surgical methods. Ten patients were treated with greater trochanteric osteotomy combined with Kocher-Langenbeck approach as the observation group, including 5 males and 5 females, aged from 18 to 75 years old. Ten patients were treated with Kocher-Langenbeck approach alone as the control group, including 7 males and 3 females, aged from 18 to 71 years old. Matta reduction criteria were used to evaluate the reduction quality of the two groups, and Harris score was used to compare the hip function of the two groups at the latest follow-up. The operation time, blood loss and postoperative complications of the two groups were analyzed. All patients were followed up for 10 to 24 months. According to the Matta fracture reduction quality evaluation criteria, the observation group achieved anatomical reduction in 6 cases, satisfactory reduction in 3 cases, and unsatisfactory reduction in 1 case, while the control group only achieved anatomical reduction in 3 cases, satisfactory reduction in 3 cases, and unsatisfactory reduction in 4 cases. At the final follow-up, the Harris hip score ranged from 71.4 to 96.6 in the observation group and 65.3 to 94.5 in the control group. According to the results of Harris score. The hip joint function of the observation group was excellent in 6 cases, good in 3 cases, and fair in 1 case. The hip joint function of the control group was excellent in 2 cases, good in 3 cases, fair in 3 cases, and poor in 2 cases. In the observation group, the intraoperative blood loss ranged from 300 to 700 ml, and the operation duration ranged from 120 to 180 min;in the control group, the intraoperative blood loss ranged from 300 to 650 ml, and the operation duration ranged from 100 to 180 min. Complications in the observation group included 1 case of traumatic arthritis and 1 case of heterotopic ossification, while complications in the control group included 3 cases of traumatic arthritis, 3 cases of heterotopic ossification and 1 case of hip abduction weakness. Trochanteric flip osteotomy combined with the Kocher-Langenbeck approach significantly improved anatomical fracture reduction rates, enhanced excellent and good hip joint function outcomes, and reduced surgical complication incidence compared to the Kocher-Langenbeck approach alone. Clinical application of this combined approach is promising, although larger studies are needed for further validation.

Poster 222: Long-term Survivorship in Patients with Coxa Profunda and Acetabular Overcoverage: An Average 11-Year Follow-up After Hip Arthroscopy

Objectives: A prior study investigating 2-year patient-reported outcomes (PROs) following hip arthroscopy found that patients with coxa profunda and acetabular overcoverage report worse improvements yet similar overall outcomes scores. Regarding conversion to total hip arthroplasty (THA), however, patients with coxa profunda and overcoverage experienced significantly lower rates of survivorship (88.9% vs 100%; p = 0.04). When considering long-term outcomes, a recent study by Domb et al. found an 85.7% 10-year survivorship in patients after hip arthroscopy. Currently, there remains a paucity of literature on the effects of a deep acetabular socket and pincer-type femoroacetabular impingement on patient outcomes beyond 2-years follow-up. The objective of the present study was to report the long-term survivorship, revision surgery rate, patient satisfaction, pain level, and functional outcome scores in patients with coxa profunda and acetabular overcoverage following hip arthroscopy. Methods: This was an institutional review board-approved retrospective cohort study of patients with coxa profunda and a LCE angle &gt; 40° who underwent hip arthroscopy for labral tears or FAI between November 2002 and May 2013. After failing conservative management, all patients were treated by a single surgeon and received the same capsulotomy technique and postoperative protocol. Patients with a minimum 8-years follow-up, complete PROs, the presence of coxa profunda as indicated by the acetabular wall projecting medial to the ilioischial line, and a LCE angle &gt; 40° were included (Figure 1). Patients with severe osteoarthritis (Tönnis osteoarthritis grade &gt; 2) or any previous hip surgeries were excluded. Patients meeting inclusion and exclusion criteria represented the overcoverage cohort (OC) and were matched 1:1 by sex, age within 8 years, body mass index (BMI) within 5 kg/m2, Tönnis grade, and labral treatment (repair vs debridement) to a matched control (MC) cohort that had a LCE angle between 25° and 40°. Collected postoperative outcomes include conversion to THA, revision hip arthroscopy, patient satisfaction, pain level (0-100), number of corticosteroid injections, and 6 PROs (modified Harris Hip Score (mHHS), Nonarthritic Hip Score (NAHS), Lower Extremity Functional Scale (LEFS), Hip Outcome Score (HOS)–Activities of Daily Living (HOS-ADL), HOS–Sports Specific subscale (HOS-SSS), and 33-item International Hip Outcome Tool (iHOT-33). Pearson χ2 test and Fisher exact test were used to compare categorical variables; two-sample t-tests were used to compare continuous variables. The threshold for statistical significance was set to 0.05. A survival analysis was performed using Kaplan-Meier curves. All statistical analyses were performed using Stata software (version 18.0; StataCorp). Results: A total of 38 patients in the OC cohort were 1:1 matched with 38 patients in the MC cohort. There were no differences in patient demographics including age, BMI, sex, Tönnis grade, labral treatment, follow-up duration, and Beck classification of labral damage or transition zone (chondrolabral junction) cartilage damage (Table 1). At an average of 11.3 years postoperatively (minimum 8-years follow-up), patients in the OC and MC cohort experienced similar rates of conversion to THA (OC: 11 [28.9%] vs MC: 6 [15.8%]; p = .169) and revision hip arthroscopy (OC: 4 [10.5%] vs MC: 1 [2.6%]; p = .165). The average time from primary hip arthroscopy to conversion to THA was 8.0 ± 6.5 years for OC and 3.7 ± 3.0 years for MC (p = .144) with the OC cohort converting to THA between 6.5 months to 17.14 years while the MC cohort ranged from 4.8 months to 7.8 years. Age at conversion to THA was 54.3 ± 8.0 years for the OC cohort and 59.0 ± 4.0 years for the MC cohort (p = .195). By Kaplan-Meier survival analysis, patients showed similar rates of survivorship (84.2%) at 12 years after hip arthroscopy; however, OC patients showed a 13.1% decrease in long-term survivorship (71.1%) between years 12 and 18 (Figure 2). Additionally, OC and MC patients showed similar levels of patient satisfaction, pain level, postoperative corticosteroid injections, and scores for all 6 PROs (Table 2). Conclusions: Patients with coxa profunda and overcoverage (LCE angle &gt; 40°) showed similar levels of survivorship, revision arthroscopy, patient satisfaction, pain level, number of corticosteroid injections, and PROs to a 1:1 matched cohort of patients with normal acetabular coverage (LCE angle between 25° and 40°) at a minimum 8-years after primary hip arthroscopy. When analyzing long-term survivorship after 12 years, however, patients with overcoverage showed a 13.1% decrease in long-term survivorship (71.1%) compared to a matched control cohort. Overall, a greater focus on extended follow-up care after hip arthroscopy is needed to improve long-term survivorship in patients with a deep acetabular socket and pincer-type femoroacetabular impingement.

Surgical treatment outcomes of acetabular posterior wall and posterior column fractures using 3D printing technology and individualized custom-made metal plates: a retrospective study

BackgroundFractures involving the posterior acetabulum with its rich vascular and neural supply present challenges in trauma orthopedics. This study evaluates the effectiveness of 3D printing technology with the use of custom-made metal plates in the treatment of posterior wall and column acetabular fractures.MethodsA retrospective analysis included 31 patients undergoing surgical fixation for posterior wall and column fractures of the acetabulum (16 in the 3D printing group, utilizing 3D printing for a 1:1 pelvic model and custom-made plates based on preoperative simulation; 15 in the traditional group, using conventional methods). Surgical and instrument operation times, intraoperative fluoroscopy frequency, intraoperative blood loss, fracture reduction quality, fracture healing time, preoperative and 12-month postoperative pain scores (Numeric Rating Scale, NRS), hip joint function at 6 and 12 months (Harris scores), and complications were compared.ResultsThe surgical and instrument operation times were significantly shorter in the 3D printing group (p < 0.001). The 3D printing group exhibited significantly lower intraoperative fluoroscopy frequency and blood loss (p = 0.001 and p < 0.001, respectively). No significant differences were observed between the two groups in terms of fracture reduction quality, fracture healing time, preoperative pain scores (NRS scores), and 6-month hip joint function (Harris scores) (p > 0.05). However, at 12 months, hip joint function and pain scores were significantly better in the 3D printing group (p < 0.05). Although the incidence of complications was lower in the 3D printing group (18.8% vs. 33.3%), the difference did not reach statistical significance (p = 0.433).ConclusionCombining 3D printing with individualized custom-made metal plates for acetabular posterior wall and column fractures reduces surgery and instrument time, minimizes intraoperative procedures and blood loss, enhancing long-term hip joint function recovery.Clinical Trial Registration12/04/2023;Trial Registration No. ChiCTR2300070438; http://www.chictr.org.cn.

A case report: Posterior acetabular deficiency treated with femoral head autograft and hybrid total hip arthroplasty

As a choice for treating acetabular deficiencies, total hip arthroplasty (THA) is beset with many drawbacks, particularly in relation to untreated fractures and post-surgery complications. Furthermore, it is hard to ensure long-term fixation of the acetabular shell. In our case, a 52-year-old male manual laborer presented with complaints of a painful limp of the left lower limb with gross restriction of movements in the left hip joint. Previously, the patient had undergone open reduction and posterior acetabular wall plate fixation 2 years back and implant exit had been done 1 year before due to complaints of pain. We treated the patient with hybrid THA. To rectify the acetabular defect, we used a femoral head autograft, securing it with screws, and supporting it with a plate posteriorly. After 1 year, there was good graft consolidation sans acetabular component displacement as evidenced by radiography. A Harris hip score of 79.7 indicated good functionality. Therefore, hybrid THA with reconstruction is a good option for treating post-traumatic arthritis with acetabular wall deficiencies. Although the procedure is difficult to carry out, it yields better results in terms of lessened pain, enhanced stability, and better functionality.

Sleep quality and psychological health in patients with pelvic and acetabulum fractures: a cross-sectional study

Background and objectivesIt is known that difficulty sleeping after a fracture can have negative effects on both mental and physical health and may prolong the recovery process. The objective of this study is to explore how sleep quality and psychological health are linked in patients with pelvic and acetabulum fractures.MethodsA study was conducted on 265 patients between 2018 and 2022 who had suffered pelvic and acetabulum fractures. The study examined various factors, including age, gender, cause of injury, post-operative complications, and injury severity. The study employed ordinal logistic regression to examine the relationship between various pelvic fractures and seven subscales of the Majeed Pelvic Score (MPS), as well as the Sleep Disorder Questionnaire (SDQ) and Beck Depression Inventory (BDI). The study focused on the postoperative outcome one year after surgery, and each patient was assessed at the one-year mark after surgical intervention. Additionally, the study evaluated the functional outcome, sleep quality, and psychological disorders of the patients.ResultsFrom 2018 to 2022, a total of 216 patients suffered from pelvic and acetabulum fractures. Among them, 6.6% experienced borderline clinical depression, and 45.2% reported mild mood disturbances. Anxiety was found to be mild to moderate in 46% of Tile C and posterior acetabulum wall fracture patients. About 24.8% of patients reported insomnia, while 23.1% reported sleep movement disorders. However, no significant correlation was found between fracture types and sleep disorders. The mean Majeed pelvic score (MPS) was 89.68.Conclusions Patients with pelvic and acetabular fractures typically experience functional improvement, but may also be at increased risk for insomnia and sleep movement disorders, particularly for certain types of fractures. Psychological well-being varies between fracture groups, with signs of borderline clinical depression observed in some cases. However, anxiety levels do not appear to be significantly correlated with pelvic and acetabular fractures.

Résultats à long terme de l’arthroplastie totale dans les luxations congénitales de la hanche. Étude rétrospective des résultats avec 10 à 20 ans de recul

Introduction: The impact of bone deformities, previous surgeries, and the surgical technique in total hip arthroplasty (THA) for congenital dislocation of the hip (CDH) at a long-term has not been clearly defined yet. In this single-centre observational study we sought to assess patients undergoing THA due to osteoarthritis secondary to severe CDH with low or high dislocation ten- to 20-years after surgery. To determine this purpose, we assessed: 1) THA-related complications and reoperations; 2) the clinical outcome, patients´ satisfaction and radiological results; and 3) the possible risk factors for reoperation with particular attention to the surgical technique and the influence of prior surgeries.Hypothesis: We hypothesized that an anatomical reconstruction of the hip would decrease the reoperations rates in patients undergoing THA with severe CDH.Methods: Seventy-five patients (85 hips) operated between 1999 and 2012 at our large tertiary hospital were analyzed. Fifty-six hips were diagnosed as low dislocation (group 1) and 29 hips as high dislocation (group 2). The existence of prior surgeries was frequent: group 1, pelvic osteotomies 6 hips, femoral osteotomies 7, tectoplasty (shelf) 6, resection arthroplasty 1 and lowering of the greater trochanter 1; group 2 included pelvic osteotomies 10 hips, femoral osteotomies 10, and a femoral lengthening 2. The number of additional procedures during THA was: group 1 (19/56 (34%)), acetabular roof bone autograft 8 hips, acetabular medial wall autograft 2, hardware removal 6, extended femoral osteotomy 2, and a femoral shortening 1; group 2 (20/29 (69%)), acetabular bone autograft 12 hips, medial autograft 1, hardware removal 1, extended femoral osteotomy 2, and a femoral shortening 4 hips The clinical and the radiological analysis were compared in both groups for a minimum follow-up of ten years. Cox regression models were used to detect risk factors for reoperation.Results: Nine patients (13.8%) required reoperation for the following reasons: cup loosening (5 hips), periprosthetic femoral fracture (3) and stem loosening (1); seven had prior surgeries. The 12-year survival rate for reoperation for any reason was 96.3% (95% Confidence Interval (CI) 91.2-100) in group 1 and 75.7% (95% CI, 65.8-90.8) in group 2 (p=0.003). Patients with high dislocation (p=0.02, Hazard Ratio (HR): 6.25, 95% CI, 1.26-30.9) and those with an acetabular component inclination placed out of the target zone between 35º and 50º (p=0.03, HR: 4,27, 95% CI, 1.13-16.1) had a higher risk of reoperation.Discussion: An optimal placement of the acetabular component decreased the reoperation rates in patients undergoing THA for severe CDH. Hips with high dislocation and the existence of prior surgery can affect THA implantation.Level of Evidence: III; retrospective; comparative

The Association of Acetabulum Fracture and Mechanism of Injury with BMI, Days Spent in Hospital, Blood Loss, and Surgery Time: A Retrospective Analysis of 67 Patients.

Background and Objectives: The objective of this retrospective study was to investigate the association between acetabulum fractures; the mechanism of injury; and variables such as BMI, duration of hospital stay, blood loss, and surgery time. By exploring these factors, we aim to enhance our understanding of them and their impact on the healing process and the subsequent management of pelvic fractures. Materials and Methods: This study included 67 of 136 consecutive patients who were admitted for pelvic ring fracture surgery between 2017 and 2022. The data were collected prospectively at a single trauma center. The inclusion criteria were acetabulum fractures and indications for operative treatment. The exclusion criteria were non-operative treatment for acetabular and pelvic ring fractures, fractures requiring primary total hip arthroplasty (THA), and periprosthetic acetabular fractures. Upon admission, all patients underwent evaluation using X-ray and computed tomography (CT) scans of the pelvis. Results: The present study found no statistically significant differences between the examined groups of patients with pelvic fractures in terms of BMI, surgery duration, length of hospital stay, and blood transfusion. However, two notable findings approached statistical significance. Firstly, patients who experienced a fall from height while sustaining a pelvic fracture required a higher number of blood transfusions (2.3 units) than those with other mechanisms of injury which was close to achieving statistical significance (p = 0.07). Secondly, patients undergoing posterior wall stabilization required a significantly lower number of blood transfusions than those with other specific pelvic injuries (0.33 units per patient), approaching statistical significance (p = 0.056). Conclusions: The findings indicated that factors such as BMI, time of surgery, blood loss, and the duration of hospital stay were not directly correlated with the morphology of acetabular fractures, the presence of additional trauma, or the mechanism of injury. However, in the studied group, the patients whose mechanism of trauma involved falling from height had an increased number of blood transfusions compared to other groups. Moreover, the patients who had surgery due to posterior wall acetabulum fracture had decreased blood transfusions compared to those with other Judet and Letournel types of fractures. Additionally, they had the shortest duration of surgery.

Threshold for anterior acetabular component overhang correlated with symptomatic iliopsoas impingement after total hip arthroplasty.

Mechanical impingement of the iliopsoas (IP) tendon accounts for 2% to 6% of persistent postoperative pain after total hip arthroplasty (THA). The most common initiator is anterior acetabular component protrusion, where the anterior margin is not covered by anterior acetabular wall. A CT scan can be used to identify and measure this overhang; however, no threshold exists for determining symptomatic anterior IP impingement due to overhang. A case-control study was conducted in which CT scan measurements were used to define a threshold that differentiates patients with IP impingement from asymptomatic patients after THA. We analyzed the CT scans of 622 patients (758 THAs) between May 2011 and May 2020. From this population, we identified 136 patients with symptoms suggestive of IP impingement. Among them, six were subsequently excluded: three because the diagnosis was refuted intraoperatively, and three because they had another obvious cause of impingement, leaving 130 hips (130 patients) in the study (impingement) group. They were matched to a control group of 138 asymptomatic hips (138 patients) after THA. The anterior acetabular component overhang was measured on an axial CT slice based on anatomical landmarks (orthogonal to the pelvic axis). The impingement group had a median overhang of 8 mm (interquartile range (IQR) 5 to 11) versus 0 mm (IQR 0 to 4) for the control group (p < 0.001). Using receiver operating characteristic curves, an overhang threshold of 4 mm was best correlated with a diagnosis of impingement (sensitivity 79%, specificity 85%; positive predictive value 75%, negative predictive value 85%). Pain after THA related to IP impingement can be reasonably linked to acetabular overhang if it exceeds 4 mm on a CT scan. Below this threshold, it seems logical to look for another cause of IP irritation or another reason for the pain after THA before concluding that impingement is present.

The Value of Computed Tomography Scan in Three-dimensional Planning and Intraoperative Navigation in Primary Total Hip Arthroplasty.

Total hip arthroplasty (THA) is a frequently performed procedure; the objective is restoration of native hip biomechanics and achieving functional range of motion (ROM) through precise positioning of the prosthetic components. Advanced three-dimensional (3D) imaging and computed tomography (CT)-based navigation are valuable tools in both the preoperative planning and intraoperative execution. The aim of this study is to provide a thorough overview on the applications of CT scans in both the preoperative and intraoperative settings of primary THA. Preoperative planning using CT-based 3D imaging enables greater accuracy in prediction of implant sizes, leading to enhancement of surgical workflow with optimization of implant inventory. Surgeons can perform a more thorough assessment of posterior and anterior acetabular wall coverage, acetabular osteophytes, anatomical landmarks, and thus achieve more functional implant positioning. Intraoperative CT-based navigation can facilitate precise execution of the preoperative plan, to attain optimal positioning of the prosthetic components to avoid impingement. Medial reaming can be minimized preserving native bone stock, which can enable restoration of femoral, acetabular, and combined offsets. In addition, it is associated with greater accuracy in leg length adjustment, a critical factor in patients' postoperative satisfaction. Despite the higher costs and radiation exposure, which currently limits its widespread adoption, it offers many benefits, and the increasing interest in robotic surgery has facilitated its integration into routine practice. Conducting additional research on ultra-low-dose CT scans and examining the potential for translation of 3D imaging into improved clinical outcomes will be necessary to warrant its expanded application.

Dislocation Does Not Seem To Be an Absolute Factor Effecting the Short- to Medium-Term Poor Prognosis of Patients with Acetabular Posterior Wall Fracture.

Dislocation is a complication of acetabular fractures involving the posterior wall, but whether dislocation is an absolute factor impacting the short- to medium-term prognosis of the hip joint remains controversial. This study aimed to compare the short- to medium-term clinical and radiological results among patients diagnosed with an acetabular fracture involving the posterior wall, with or without dislocation.Seventy-nine patients diagnosed with an acetabular fracture involving the posterior wall were retrospectively divided into posterior dislocation and non-dislocation groups. All fractures were open reduction + internal fixation with a plate screw combination through the single Kocher-Langenbeck approach. The short- to medium-term radiographic outcomes of follow-up were evaluated using the Matta radiologic grading system, while the clinical outcomes were evaluated using the modified Merle d'Aubigné-Postel evaluation system.The mean follow-up duration for all patients was 43.90 (range 24-75) months. Both groups achieved similar short- to medium-term clinical and radiographic results. There seems to be no significant differences between the two groups regarding the short- to medium-term assessment of clinical and radiographic results and the occurrence of postoperative complications (p>0.05).In patients with acetabular fractures involving the posterior wall, hip dislocation is probably not an absolute determinant of a poor outcome. Even with early reduction, the short- to medium-term prognosis results appear similar to those of patients without dislocation.

Traumatic gluteus maximus femoral insertion tear

With hip fracture dislocation, there is a wide variety of injuries, and one of the least and rarely to be seen is a gluteus maximus femoral insertion tear. We report this case to encourage further sharing of similar cases, establish a treatment protocol, and avoid such potential complications. We present this rare case of a 36-year-old male, a victim of a severe motor vehicle collision, who presented with a head contusion, right gluteus maximus femoral insertion tear, right hip dislocation with closed posterior wall acetabulum fracture, intra-articular incarcerated fragment, and multiple fractures. After the reduction of his hip and splinting of his concomitant fractures and optimization of the general condition, he underwent open reduction internal fixation of the posterior acetabulum wall. Intraoperatively, he found to have a rupture of gluteus maximus and short external rotators for which he had gluteus maximus direct repair to its insertion and partial repair for his severely damaged external rotators. The patient developed a surgical site infection post operation, treated by multiple sessions of irrigation and debridement and culture-based intravenous venous antibiotics for six weeks. At the 7-month outpatient clinical follow-up, the patient function was able to mobilize with a limping gait using a cane and extreme limitation of his abduction, external rotation, and extension due to the development of heterotopic ossification, which could be due to prolonged intensive care unit admission due to head injury or hip external rotators rupture or multiple surgeries that he underwent. This rare finding of gluteus maximus ruptur is the first of a kind in our institute, and such a finding to be considered before treatment of such severe injuries and questioning the need for magnetic resonance imaging for traumatic hip dislocations plus prophylactic treatment of heterotopic ossification to optimize the functional outcome post-operative.

Virtual preoperative planning and 3D-printed templates for pre-contoured plates in treatment of acetabular posterior wall fractures

To evaluate the feasibility and accuracy of virtual preoperative planning and 3D-printed templates for pre-contoured plates for the treatment of posterior wall fractures of the acetabulum. A retrospective analysis of 29 patients with posterior acetabular wall fractures treated between August 2017 and March 2021 were divided into 2 groups based on whether to use preoperative virtual planning and 3D printed template. In 3D-printing group, there were 14 patients, including 10 males and 4 females； aged from 21 to 53 years old；CT-based virtual surgical planning was done using Mimics and 3-Matic software and 3D-printed templates for pre-contoured plates were adopted. In conventional group, there were 15 patients, including 10 males and 5 females；aged from 19 to 55 years old；conventional method of intra-operative contouring to adapt the plate to the fracture region was adopted. Blood loss, surgical time, radiographic quality of reduction, and hip function were compared between groups. The difference in operation time and intraoperative blood loss was significant（P<0.05）. Twenty-three patients were followed up from 12 to 30 months, and the fractures in both groups healed with a healing time of 3 to 6 months. At the last follow-up, the Merle d'Aubign-Postel score of the 3D printed group was lower than that of the conventional group（P<0.05）, with no significant differences in walking ability, hip mobility and total score（P>0.05）. In 3D printing group, 6 cases were excellent, 5 cases were good, 3 cases were fair；in conventional group, 5 cases were excellent, 5 cases were good, 4 cases were fair, 1 case was worse；no significant difference between two groups（P>0.05）. Virtual preoperative planning and 3D-printed templates for pre-contoured plates can reduce operative time and the blood loss of surgery, improve the quality of reduction. This method is efficient, accurate and reliable to treat acetabular posterior wall fractures.

Long-term results of total hip arthroplasty in severe congenital hip disease: A ten- to 20-year follow-up study

IntroductionThe impact of bone deformities, previous surgeries, and the surgical technique in total hip arthroplasty (THA) for congenital dislocation of the hip (CDH) at a long-term has not been clearly defined yet. In this single-centre observational study we sought to assess patients undergoing THA due to osteoarthritis secondary to severe CDH with low or high dislocation ten- to 20-years after surgery. To determine this purpose, we assessed: (1) THA-related complications and reoperations; (2) the clinical outcome, patients’ satisfaction and radiological results; and (3) the possible risk factors for reoperation with particular attention to the surgical technique and the influence of prior surgeries. HypothesisWe hypothesized that an anatomical reconstruction of the hip would decrease the reoperations rates in patients undergoing THA with severe CDH. MethodsSeventy-five patients (85 hips) operated between 1999 and 2012 at our large tertiary hospital were analyzed. Fifty-six hips were diagnosed as low dislocation (group 1) and 29 hips as high dislocation (group 2). The existence of prior surgeries was frequent: group 1, pelvic osteotomies 6 hips, femoral osteotomies 7, tectoplasty (shelf) 6, resection arthroplasty 1 and lowering of the greater trochanter 1; group 2 included pelvic osteotomies 10 hips, femoral osteotomies 10, and a femoral lengthening 2. The number of additional procedures during THA was: group 1 (19/56 [34%]), acetabular roof bone autograft 8 hips, acetabular medial wall autograft 2, hardware removal 6, extended femoral osteotomy 2, and a femoral shortening 1; group 2 (20/29 [69%]), acetabular bone autograft 12 hips, medial autograft 1, hardware removal 1, extended femoral osteotomy 2, and a femoral shortening 4 hips. The clinical and the radiological analysis were compared in both groups for a minimum follow-up of ten years. Cox regression models were used to detect risk factors for reoperation. ResultsNine patients (13.8%) required reoperation for the following reasons: cup loosening (5 hips), periprosthetic femoral fracture (3) and stem loosening (1); seven had prior surgeries. The 12-year survival rate for reoperation for any reason was 96.3% (95% confidence interval [CI] 91.2–100) in group 1 and 75.7% (95% CI, 65.8–90.8) in group 2 (p=0.003). Patients with high dislocation (p=0.02, hazard ratio [HR]: 6.25, 95% CI, 1.26–30.9) and those with an acetabular component inclination placed out of the target zone between 35° and 50° (p=0.03, HR: 4.27, 95% CI, 1.13–16.1) had a higher risk of reoperation. DiscussionAn optimal placement of the acetabular component decreased the reoperation rates in patients undergoing THA for severe CDH. Hips with high dislocation and the existence of prior surgery can affect THA implantation. Level of evidenceIII; retrospective; comparative.

3D printing-assisted total hip arthroplasty and internal fixation for the treatment of fresh acetabular fracture and femoral head necrosis: A case report

Rationale: Posterior wall comminuted fractures of the acetabulum are typically caused by high-energy trauma, and the complex anatomical structure of the acetabulum makes their treatment challenging. However, reports of the treatment of fresh acetabular fractures combined with femoral head necrosis are extremely rare. Patient concerns: A 57-year-old male, injured in a car accident, presented with right hip pain and limited mobility. At the age of 50, the patient was diagnosed with avascular necrosis of the right femoral head, experiencing right hip pain and a limp while walking, for which conservative treatment was initiated. Diagnosis: The patient was clinically diagnosed with fresh comminuted posterior wall acetabular fracture and late-stage femoral head necrosis. Interventions: We applied 3D printing technology and computer-assisted virtual surgical techniques for preoperative planning, simulated fracture reduction, and designed personalized bone plates and screws for fixation of the posterior wall of the acetabulum. A single-stage total hip arthroplasty was performed to treat femoral head necrosis. Outcomes: He began walking with the assistance of a walker 1 month after surgery, and at 6 months post-surgery, the acetabular posterior wall fracture had effectively healed, allowing the patient to return to work. Lessons: The application of 3D printing technology in acetabular internal fixation and total hip arthroplasty is helpful for fracture assessment, facilitates smooth surgery, promotes fracture reduction and healing, restores hip joint function, and ensures a high level of safety.

The Avian Acetabulum: Small Structure, but Rich with Illumination and Questions

The idea that birds are maniraptoran theropod dinosaurs is now considered an evolutionary consensus. An “open” (i.e., completely or substantially perforate) acetabulum is considered an important synapomorphy verifying the bird–dinosaur nexus. Here, I present anatomical evidence from the acetabulum and its important appurtenances, the supracetabular crest and the antitrochanter, that hip anatomy differs substantially between dinosaurs and birds. Given the thin bone of the acetabular walls and the varied tissue, both hard and soft, in the acetabular region and especially the lower part of the basin, it is apparent that many avian skeletons exhibit some anatomical loss of soft tissue and thin bone, some perhaps related to changes in gait, but also in part related to the dramatic trend in bone reduction associated with flight, especially in more advanced crown taxa. Many basal birds and early diverging neornithines tend to have a nearly closed or partially closed acetabula, thus rendering the current terms “open” or “closed” acetabula inaccurate; they should be modified or replaced. Given new evidence presented here, the relationship of “dinosaurs” and birds must be re-evaluated.

NEW INCENTIVES AND PITFALLS IN PATIENT-SPECIFIC 3D-PRINTED PELVIC IMPLANTS

Custom 3D printed implants can be anatomically designed to assist in complex surgery of the bony pelvis in both orthopaedic oncology and orthopaedic reconstruction surgery.This series includes patients who had major pelvic bone loss after initially presenting with tumours, fractures or infection after previous total hip arthroplasty. The extent of the bone loss in the pelvis was severe and therefore impossible to be reconstructed by conventional ‘off –the-shelve’ implants. The implant was designed considering the remaining bony structures of the contra-lateral hemi- pelvis, to provide an anatomical, secured support for the reconstructed hip joint. The latter was realised by strategically orientated screws and by porous structures (an integral part of the implant), which stimulates osseointegration. A custom pelvic implant was designed, manufactured and 3D printed. Reconstruction of the pelvis was performed together with a cemented (bipolar bearing) acetabular cup. In some cases, a proximal femoral replacement was also necessary to compensate for bony defects.All patients had sufficient range of motion (ROM) at the hip with post-operative stability. It has been verified, at six and twelve months postoperatively, that there is a strong hold of the implant due to osseointegration. Additionally, in patients whose posterior acetabular wall was missing, it was discovered that the implant assisted in bone formation and covered the entire posterior surface of the implant.All patients in this study managed with this novel treatment option, proved to have a stable pelvic reconstruction with restoration of leg lengths, improvement of strength and independent ambulation at short and medium term follow-up.