Periacetabular Bone Research Articles

Mini-open periacetabular cementoplasty for periacetabular bone metastasis: a report of two cases

Mini-open periacetabular cementoplasty for periacetabular bone metastasis: a report of two cases

Safety and efficacy of combined acetabular reconstruction and microwave ablation in the treatment of periacetabular metastatic disease: a retrospective clinical evaluation.

The periacetabular bone defects caused by metastatic disease often necessitate acetabular reconstruction and various techniques have been employed with varying degrees of success. The purpose of this study was to evaluate the efficacy and safety of acetabular reconstruction in conjunction with adjuvant microwave ablation as a surgical intervention for patients with periacetabular metastases. Between January 2019 and September 2023, 17 consecutive patients with different tumor subtypes required surgical intervention for periacetabular metastases. The acetabular reconstruction was performed by utilizing an acetabular reconstructive cage and cement total hip arthroplasty with microwave ablation. A retrospective review was performed to assess pain relief, intraoperative details and postoperative complications. Functional status following procedures was determined by the 1993 Musculoskeletal Tumor Society (MSTS) score and the overall survival of patients was estimated by Kaplan-Meier analysis. In total, 8 males and 9 females were included with an average age of 48.6 years (range 34-66). Patients reported a significant improvement in the level of pain and the mean VAS score declined from 7.7 preoperatively to 2.2 postoperatively. Of the 17 patients, 16 could ambulate either independently (6 patients) or using a walking aid (10 patients) with a mean MSTS score of 18.9. The median follow-up was 9.0 months. Nine patients were alive at the most recent follow-up with overall survival of 40.9% at 12 months and 30.7% at 36 months, respectively. In selected patients with periacetabular metastasis, the utilization of an acetabular cage and cement total hip arthroplasty presents a less invasive reconstruction technique. The incorporation of adjuvant microwave ablation has shown promise in providing long-lasting pain relief, reducing intraoperative bleeding, and improving local tumor control. However, further research and extended follow-up are necessary to establish the effectiveness of this procedure.

The role of acetabular cement augmentation in 2-stage revision arthroplasty for prosthetic joint infection of the hip.

In the treatment of chronic prosthetic joint infection (PJI) of the hip, two-stage exchange arthroplasty is commonly employed. Various spacer designs, including Hemi-Spacers and Articulating Spacers, are utilized during this process. However, these spacers are associated with a high rate of mechanical complications and pose a risk of progressive bone loss. This study aims to compare these two types of spacers in terms of mechanical complications, center of rotation (COR) restoration, and preservation of acetabular bone stock. From 2019 to 2022, patients who underwent two-stage exchange arthroplasty for hip PJI across three hospitals were retrospectively reviewed. Data including demographic, clinical, and microbiological information were collected. Radiographic imaging was analyzed to measure acetabular bone erosion, COR, and periacetabular bone resected. Additionally, the average surgical time in the first and second stages, mechanical complications, and the mean duration of the inter-stage period were recorded. Forty patients were divided into two groups: Group A (Articulating Spacer, n = 23) received a preformed femur spacer with acetabular cement augmentation, while Group B (Hemi-Spacer, n = 17) received a preformed femur spacer alone. Acetabular cement augmentation slightly prolonged the first stage but facilitated a faster second stage during subsequent reimplantation. Spacer dislocation rates were 8.7% in Group A and 17.6% in Group B during the interstage period. Radiographic analysis revealed a statistically significant greater degree of acetabular erosion in Group B. A significant difference in Vertical-COR differential was observed, with a more proximalized revision cup compared to the primary cup in Group B, and Horizontal-COR values closer to the native hip in Group A. Dynamic spacers with acetabular cement augmentation help preserve peri-acetabular bone stock and prevent progression of acetabular bone erosion during the inter-stage period. Additionally, these spacers reduce the dislocation rates, making reimplantation easier and leading to better restoration of hip biomechanics during the second procedure.

The Modified Harrington Procedure for Metastatic Peri-Acetabular Bone Lesion Using a Novel Highly Porous Titanium Revision Shell with Long Lever Arm Screw.

Background and Objectives: Peri-acetabular metastases often lead to significant pain and functional impairment. Surgical interventions, including the Harrington procedure, aim to address these challenges. This study evaluates a modified Harrington procedure using the MUTARS® PRS® (Pelvic Revision Shell) with an 8 mm fixation screw for severe acetabular defects resulting from metastatic lesions. Materials and Methods: Retrospective analysis of 12 patients treated between January 2020 and December 2023 was conducted. The procedure involved using the novel MUTARS® PRS® with an 8 mm in diameter dome screw (length 70-100 mm). Outcome measures included implant positioning changes, complication rates, functional outcomes, implant longevity, and patient survival. Radiological assessments were performed postoperatively, with follow-ups at 3, 6, 12 months, and annually thereafter. Results: Average follow-up was 15 ± 11 months, with 67% patient survival at 1 year and 44% at 2 years. Implant survivorship remained 100%. Harris Hip Score improved significantly from 37 ± 22 preoperatively to 75 ± 15 at the last follow-up. No revisions involving implant components were reported. Complications occurred in 5 of 12 patients. Overall, PRS® demonstrates effective osseous ingrowth, high primary stability, immediate full weight-bearing, and low complication rates. Conclusions: PRS® integrates facilitating osseous ingrowth for preferable long-term outcomes, while efficiently transmitting the weight-bearing load to the intact aspect of the pelvis using a long 8 mm lever screw, enhancing the primary stability of the construct. It proves to be an effective and reproducible technique for managing destructive metastatic lesions of the acetabulum and peri-acetabular region, even in irradiated bone.

The Measurement of the Oxidative Index of Polyethylene Obtained during Revision Hip Arthroplasty and Assessment of Its Variability Depending on the Degree of Osteolysis, Implantation Time, as Well as the Size and Material of the Utilized Head.

Background/Objectives: Aseptic loosening is the leading cause of late revision in total hip arthroplasty, primarily due to degenerative oxidation of polyethylene components, leading to wear particle formation and periacetabular osteolysis. This study aimed to analyze the oxidation levels in polyethylene liners and cemented cups retrieved from revision surgeries using Fourier-transform infrared spectroscopy (FTIR) and to explore the correlation between oxidation levels and factors such as head size, head material, fixation method, and implant survival time. Methods: Polyethylene liners and cups were analyzed post-revision surgery to assess oxidation levels, which were then compared to periacetabular bone loss measured by the Paprosky classification. This study evaluated the impact of head size (28 mm vs. 32 mm), head material (ceramic vs. metal), and fixation methods on oxidation. The relationship between the mean oxidation index (OI) and implant survival time was also investigated. Results: There was a significant positive correlation between the mean oxidation index of the polyethylene components and the severity of periacetabular osteolysis according to the Paprosky scale. While the mean OI for samples articulating with ceramic heads was lower than for those with metal heads, and the mean OI for samples with a 32 mm head size was lower than for those with a 28 mm size, these differences were not statistically significant. Furthermore, the fixation method did not affect the oxidation index, and no correlation was found between OI and the survival time of the implants. Conclusions: This study confirms a direct correlation between polyethylene oxidation and periacetabular osteolysis in hip replacements, highlighting the importance of material choice and design in potentially reducing the risk of aseptic loosening. Despite the lack of significant differences in oxidation levels based on head material and size, these factors may still play a role in the long-term outcome of hip arthroplasty, warranting further investigation.

Usefulness of a Cementless Highly-Porous Acetabular Cup in Rheumatoid Arthritis Patients Undergoing Total Hip Arthroplasty.

Total hip arthroplasty in patients with rheumatoid arthritis is difficult and leads to worse implant survival and higher risk for complications compared to osteoarthritis. Poor periacetabular bone quality might challenge the stability of the acetabular cup. Contemporary 3D-printed highly-porous titanium cup designs have become the benchmark for cementless implants; however, their usefulness in rheumatoid arthritis is still unclear. The purpose of this study was to assess the short-term results of the use of a highly-porous 3D-printed acetabular titanium cup in patients with rheumatoid arthritis. We studied a consecutive series of RA patients who underwent cementless THA between 2019 and 2020 in our center with the same 3D-printed highly-porous titanium acetabular cup. All patients were evaluated prospectively for a minimum 3-year follow-up with the Harris hip score, VAS and Roles and Maudsley score. Radiographic assessment focused on evidence of cup osseointegration. 37 RA patients, mean age at surgery of 51.3 years, were included. Mean follow-up was 3.2 years (3 to 4 years). By the last follow-up visit, the Harris hip score had increased significantly from 37.8 to 88.5, VAS had decreased from 6.1 to 1.0 and excellent satisfaction for 31 patients. All 5 Moore's radiographic signs were present in 35 hips, with only 4 signs present in the remaining 2 hips, thus indicating complete osseointegration of all cups. There were no complications on the acetabular side but one intraoperative proximal calcar fracture. 3D-printed highly porous implants used in primary THA worked well in patients with rheumatoid arthritis, showing excellent osseointegration and good clinical results in the short term.

Bipolar Head Perforation With Rhabdomyosarcoma of the Thigh: A Case Report With Literature Review.

High complication rates during the perioperative management of sarcomas around the pelvis have been reported; however, few include the detailed clinical course or complications in the late postoperative period. Radiotherapy is a multidisciplinary strategy for treating sarcomas. However, irradiated bone and soft tissues show a permanent loss of repair and immunocompetence. We present a case of pleomorphic rhabdomyosarcoma of the thigh that resulted in acetabular collapse induced by radiation and intestinal perforation during long-term follow-up. Additionally, we discuss the risk factors for late complications and pelvic reconstruction methods. A 75-year-old man presented with a 1-month history of a recurring fever. Ten years prior, he was diagnosed with pleomorphic rhabdomyosarcoma of the right thigh and underwent a wide resection and bipolar hip arthroplasty, followed by chemotherapy and radiotherapy. Radiographs showed central dislocation of the bipolar head. Computed tomography revealed free air in the hip joint and thickening of the colon wall. Colonoscopy revealed displacement of the bipolar head into the colon wall. Colon resection and hip disarticulation were performed, as the bipolar head was contaminated with intestinal contents. Currently, he is able to walk stably with a walker, and there is no evidence of recurrence or metastasis of the tumor. Irradiation of the periacetabular bone may induce resorptive destruction, resulting in future structural failure. Hardware should not be used for periacetabular bone reconstruction; the risk of pelvic organ damage should be considered when the acetabular collapse becomes deteriorated. Therefore, other reliable and permanent reconstruction options are required.

Design of 3D-printed prostheses for reconstruction of periacetabular bone tumors using topology optimization.

Background: Prostheses for the reconstruction of periacetabular bone tumors are prone to instigate stress shielding. The purpose of this study is to design 3D-printed prostheses with topology optimization (TO) for the reconstruction of periacetabular bone tumors and to add porous structures to reduce stress shielding and facilitate integration between prostheses and host bone. Methods: Utilizing patient CT data, we constructed a finite element analysis (FEA) model. Subsequent phases encompassed carrying out TO on the designated area, utilizing the solid isotropic material penalization model (SIMP), and this optimized removal area was replaced with a porous structure. Further analyses included preoperative FEA simulations to comparatively evaluate parameters, including maximum stress, stress distribution, strain energy density (SED), and the relative micromotion of prostheses before and after TO. Furthermore, FEA based on patients' postoperative CT data was conducted again to assess the potential risk of stress shielding subsequent to implantation. Ultimately, preliminary follow-up findings from two patients were documented. Results: In both prostheses, the SED before and after TO increased by 143.61% (from 0.10322 to 0.25145mJ/mm3) and 35.050% (from 0.30964 to 0.41817mJ/mm3) respectively, showing significant differences (p < 0.001). The peak stress in the Type II prosthesis decreased by 10.494% (from 77.227 to 69.123MPa), while there was no significant change in peak stress for the Type I prosthesis. There were no significant changes in stress distribution or the proportion of regions with micromotion less than 28μm before and after TO for either prosthesis. Postoperative FEA verified results showed that the stress in the pelvis and prostheses remained at relatively low levels. The results of follow-up showed that the patients had successful osseointegration and their MSTS scores at the 12thmonth after surgery were both 100%. Conclusion: These two types of 3D-printed porous prostheses using TO for periacetabular bone tumor reconstruction offer advantages over traditional prostheses by reducing stress shielding and promoting osseointegration, while maintaining the original stiffness of the prosthesis. Furthermore, in vivo experiments show that these prostheses meet the requirements for daily activities of patients. This study provides a valuable reference for the design of future periacetabular bone tumor reconstruction prostheses.

Management of metastatic bone disease of the pelvis: current concepts.

Metastatic disease of the pelvis is frequently associated with severe pain and impaired ambulatory function. Depending on the patient's characteristics, primary tumor, and metastatic pelvic disease, the treatment choice may be varied. This study aims to report on the current management options of metastatic pelvic disease. We comprehensively researched multiple databases and evaluated essential studies about current concepts of managing a metastatic bone disease of the pelvis, focusing on specific indications as well as on the result of treatment. Pelvic metastases not in the periacetabular region can be managed with modification of weight-bearing, analgesics, bisphosphonates, chemotherapy and/or radiotherapy. Minimally invasive approaches include radiofrequency ablation, cryoablation, embolization, percutaneous osteoplasty, and percutaneous screw placement. Pathological or impending periacetabular fracture, excessive periacetabular bone defect, radioresistant tumor, and persistent debilitating pain despite non-surgical treatment and/or minimally invasive procedures can be managed with different surgical techniques. Overall, treatment can be divided into nonoperative, minimally invasive, and operative based on specific indications, the expectations of the patient and the lesion. Different treatment modalities exist to manage metastatic pelvic bone disease. Decision-making for the most appropriate treatment should be made with a multidisciplinary approach based on a case-by-case basis.

Acetabular Revision with McMinn Cup: Development and Application of a Patient-Specific Targeting Device.

Surgeries of severe periacetabular bone defects (Paprosky ≥ 2B) are a major challenge in current practice. Although solutions are available for this serious clinical problem, they all have their disadvantages as well as their advantages. An alternative method of reconstructing such extensive defects was the use of a cup with a stem to solve these revision situations. As the instrumentation offered is typically designed for scenarios where a significant bone defect is not present, our unique technique has been developed for implantation in cases where reference points are missing. Our hypothesis was that a targeting device designed based on the CT scan of a patient's pelvis could facilitate the safe insertion of the guiding wire. Briefly, our surgical solution consists of a two-step operation. If periacetabular bone loss was found to be more significant during revision surgery, all implants were removed, and two titanium marker screws in the anterior iliac crest were percutaneously inserted. Next, by applying the metal artifact removal (MAR) algorithm, a CT scan of the pelvis was performed. Based on that, the dimensions and positioning of the cup to be inserted were determined, and a patient-specific 3D printed targeting device made of biocompatible material was created to safely insert the guidewire, which is essential to the implantation process. In this study, medical, engineering, and technical tasks related to the design, the surgical technique, and experiences from 17 surgical cases between February 2018 and July 2021 are reported. There were no surgical complications in any cases. The implant had to be removed due to septic reasons (independently from the technique) in a single case, consistent with the septic statistics for this type of surgery. There was not any perforation of the linea terminalis of the pelvis due to the guiding method. The wound healing of patients was uneventful, and the implant was fixed securely. Following rehabilitation, the joints were able to bear weight again. After one to four years of follow-up, the patient satisfaction level was high, and the gait function of the patients improved a lot in all cases. Our results show that CT-based virtual surgical planning and, based on it, the use of a patient-specific 3D printed aiming device is a reliable method for major hip surgeries with significant bone loss. This technique has also made it possible to perform these operations with minimal X-ray exposure.

SURGICAL PROCEDURE FOR PELVIC PERIACETABULAR BONE TUMOR DEFECTS

Pelvic bone tumor and traumatic injuries are causes to a numeric of diagnostic, treatment and subsequent obtaining of positive functionalresults problems, which significantly affects the patientʼs quality of life. The most prognostically difficult are acetabulum areas defects. Its adequate restoration affects the further walking function. Goal. To develop a surgical reconstruction of the periacetabular tumor resection defects. Methods. A new surgical reconstruction procedure of the pelvic periacetabular defects were developed and submitted. It consists in using of artificial material polyethyleneterephthalate («Attachment tube») replacing, which is pre-filled with bone allograft and sutures transosseously fixed to the pubic bone or to the pubic/ischial bones. Another «Attachment tube» fragment is used to fix the femur head to the indicated allograft implant. The strength and bioactive characteristics of the «Attachment tube» in combination with bone allograft make it possible to obtain the equivalent of the acetabulum and restorethe full weight bearing and walking function with a certain range of motion in the restored acetabulum area. Results. The proposed method was clinically tested on 9 patients with evaluated follow up. Satisfactory functional results were obtained: (52.6 ± 20.0) % on the MSTS scale. Complications were analyzed. Conclusions. The use of novel surgical procedure for pelvic periacetabular bone tumor defects has a number of advantages over the existing ones.The biological materials using, restoration of anatomical relations in the «hip joint» makes it possible to restore the lower limb function with a good range of motion. The obtained results prove authorʼs method using can give acceptable results in the treatment of periacetabulum tumor leasions patients.

Change in CT-measured acetabular bone density following total hip arthroplasty: a systematic review and meta-analysis.

Assessing peri-acetabular bone quality is valuable for optimizing the outcomes of primary total hip arthroplasty (THA) as preservation of good quality bone stock likely affects implant stability. The aim of this study was to perform a meta-analysis of peri-acetabular bone mineral density (BMD) changes over time measured using quantitative computer tomography (CT) and, second, to investigate the influence of age, sex, and fixation on the change in BMD over time. A systematic search of Embase, Scopus, Web of Science, and PubMed databases identified 19 studies that measured BMD using CT following THA. The regions of interest (ROI), reporting of BMD results, and scan protocols were extracted. A meta-analysis of BMD was performed on 12 studies that reported measurements immediately postoperatively and at follow-up. The meta-analysis determined that periacetabular BMD around both cemented and uncemented components decreases over time. The amount of BMD loss increased relative to proximity of the acetabular component. There was a greater decrease in cortical BMD over time in females and cancellous BMD for young patients of any sex. Peri-acetabular BMD decreases at different rates relative to its proximity to the acetabular component. Cancellous BMD decreases more in young patients and cortical bone decreases more in females. Standardized reporting parameters and suggested ROI to measure peri-acetabular BMD are proposed, to enable comparison between implant and patient variables in the future.

20-year Results of a 3D Titanium Mesh Coating Stability of 31 Artificial Cups.

The aim of this work was to demonstrate the bony bond strength and resilience of a three-dimensional titanium mesh coating of an artificial acetabulum produced using the diffusion bonding technique. Under the extreme conditions ranging from abrasion-related osteolysis to acetabular perforation, the degree of residual bone and the integrity of the coating were determined. The remaining zones of the (still) stable bone connection are inevitably exposed to a greater load of the layer adhesion between the titanium mesh and the core shell. The investigation was intended to provide information about the stages of damage according to Paprosky in which it was still justifiable to leave the implant in place and simply change the inlay from the purely material-technical point of view of a stable coating. The bond between bone and implant was examined with regard to a possible retention of the implant for its adaptive remodeling up to 27 years. In a retrospective study, 31 explanted human acetabular cups of the Harris-Galante II type, with an average lifetime of 19.7 years (11-27 years), were examined by means of digital area measurement to determine both the bone areas remaining on the coating and the damaged areas of the titanium mesh. Periacetabular bone loss was recorded in a modified Paprosky (PAP) damage classification. Full hemispherical sections of 4 acetabular cups with a life time of 16, 20, 22 and 27 years were examined histopathologically using the diamond cut technique. The periacetabular bone loss resulted in damage class PAP I in 8 cases, PAP IIa in 7 cases, PAP IIb in 2 cases, PAP IIc in 9 cases, PAP IIIa in 3 cases and PAP IIIa in 2 cases PAP IIIb. The average amount of bone that was still firmly attached to the coating after explantation was 17% (0-70%) of the total cup surface. Paprosky I accounted for 44.1%, and PAP IIa and IIb stadiums together a total of 17.1%. The average bone fraction of the implants no longer anchored in the host bed at stages IIc, IIIa and IIIb was 2%. The average coating damage was 11% (0-100%) and was exclusively attributable to the unstable implants of stages IIc, IIIa and IIIb. The histopathological findings showed adaptive bone remodeling, that was detectable for up to 27 years through the titanium mesh down to the interface with the solid acetabular core. The titanium wire mesh was mostly surrounded by lamellar, mature bone. The results show that the connection between the Tivanium cup and the previously oldest and unchanged sintered coating - in the form of a three-dimensional titanium mesh applied in point and line contact - is very load-resistant even under the extreme loads of periacetabular osteolysis and cup perforations. Since there was no damage to the coating in periacetabular damage stages Paprosky I, IIa and IIb, it is justifiable in these damage stages to leave the implant in situ and to continue to use it with sole replacement of the inlay, but leaving the socket shell. The third-generation acetabular cup (Trilogy) with unchanged three-dimensional titanium mesh coating has been implanted in over 1.2 million cases for 26 years. After a long service life, an increasing number of wear and tear conditions can be expected in today's mostly elderly and vulnerable patient clientele. In view of the results presented here, the early detection of damage would make it possible to avoid costly and stressful explantation of the entire acetabular cup in favor of replacing the sole inlay in Paprosky stages I, IIa and IIb.

Less is better than more with resection of periacetabular tumors - A retrospective 16 years study and literature review.

Wide resections of periacetabular tumors create a sizeable bony defect that inevitably results in severe loss of function. Reconstruction of such defects usually requires using large metal implants, a feature associated with considerable surgery extension and complications. The aim of this study is to report resection with no reconstruction of the bony defect. In this retrospective study, we reviewed a consecutive series of 16 patients diagnosed with malignant periacetabular tumors and underwent en-bloc resection without reconstructing their remaining bone defect. Records were reviewed of 16 consecutive patients diagnosed with malignant periacetabular tumors and underwent en-bloc resection without reconstructing their remaining bony defect. Measurements included: the duration of surgery, blood loss, hemoglobin levels and the need for blood transfusions, data on other hospitalization characteristics, and intraoperative and postoperative complications. Sixteen patients with malignant periacetabular bone tumors and extensive bone destruction underwent wide periacetabular tumor resection with a mean follow-up of 75 months and a mean age of 53 years. The average HOOS score was 46 (range: 20 to 76), and the mean MSTS score was 13% (range: 0 to 15). The mean operative time was 4.1 h, and the mean blood loss was 1200 ml. At their most recent follow-up, patients had a mean shortening of their operated extremity of 4.8 cm, and all could ambulate with assisting devices. Wide resection of periacetabular tumors without reconstruction provides acceptable levels of function and was associated with shorter surgical time, less blood loss and fewer postoperative complications compared to resection with reconstruction. Therefore, this approach may be considered a viable surgical option in patients with an extensive malignant periacetabular. Retrospective study.

Precise joint preserving surgery by using Three-Dimensional Printing Technology for metastatic periacetabular bone tumor: A technique note and preliminary report

Complex arthroplasties for periacetabular metastatic lesions can result in complications including infection and prosthesis loosening owing to poor bone quality. A new surgical protocol has been developed as a joint-sparing surgery to avoid complications after arthroplasties. The main surgical steps are: (a) conservative and accurate tumor resection with aid of 3D printing model-assisted preoperative resection simulation and preparation of pre-contour plate, (b) reconstruction with structural bone graft through the sandwich technique for augmentation of subchondral bone. This retrospective study consisted of 6 patients (5 with metastatic bone tumors and one with multiple myeloma). The pelvic bone resection as defined by Enneking and Dunham were typed I+II in 2 patients and type II in 4 patients. The medical records, images, musculoskeletal tumor society (MSTS) score and visual analogue scale (VAS) were used for evaluation. The mean operative time was 234minutes, and the average surgical blood loss was 1408mL. The mean follow-up period was 21 months. The mean VAS significantly decreased at postoperative 1-week and 1-year follow-up. There were no intraoperative or early postoperative complications. The median MSTS score during the final follow-up was 26 points (range, 14-28 points). Except for one case who experienced severe joint destruction, all the other five cases were classified as excellent or good (>15). With precise tumor resection and reconstruction with sandwich procedure, the joint-sparing surgery can be performed in selected patients with metastatic periacetabular tumors.

What's New in Musculoskeletal Tumor Surgery.

What's New in Musculoskeletal Tumor Surgery.

Augmenting Pathologic Acetabular Bone Loss With Photodynamic Nails to Support Primary Total Hip Arthroplasty.

BackgroundPathologic acetabular defects can undermine the stability and osseointegration of a primary total hip arthroplasty (THA) acetabular component. Our service has used photodynamic nails (PDNs) in a modified Harrington technique to provide space-filling stability to a primary acetabular implant without impeding local osseointegration. Here we describe our experience with PDN-augmented THAs.MethodsAn institutional review board-approved retrospective analysis of all patients who underwent PDN-augmented THA in the management of severe (Harrington class II or III) acetabular defects from September 1, 2020 to May 1, 2021 with at least 6 months of follow-up was performed. The primary outcome was implant survivorship. Comparisons between preoperative and 6-week postoperative visual analogue pain scores were made using the Mann-Whitney U test.ResultsSix patients were included in this case series, 5 with metastatic cancer and 1 with pelvic discontinuity and avascular necrosis following failed attempted acetabular fixation. The mean follow-up duration was 10.3 ± 4.3 months. The mean age was 75.5 ± 4.7 years, mean body mass index 27.3 ± 5.6, and 5 patients were female. All but 1 patient was American Society of Anesthesiologists (ASA) class III. Two patients required acetabular revisions, one for aseptic loosening and a second for a pathologic fracture secondary to disease progression. One patient passed away 90 days after the procedure. The mean visual analogue pain score significantly improved from 7.8 ± 1.6 to 2.0 ± 1.4 six weeks after surgery (P = .008).ConclusionsPDN augmentation of the periacetabular bone of patients with large pelvic defects yields durable pain relief and function in vulnerable hosts. PDN should be considered a part of the reconstructive surgeon’s armamentarium.

Use of custom-made acetabular components (CMAC) as part of atwo-stage procedure in patients with severe periacetabular bone loss

Implantation of custom-made acetabular components (CMAC) with load transmission onto the remaining bone stock and reconstruction of the "center of rotation" (COR) in cases of severe periacetabular bone defects. Severe periacetabular bone loss (Paprosky type IIIA/B) with or without pelvic discontinuity after septic or aseptic loosening with inadequate load capacity of the dorsal pillar and/or large supraacetabular defects. Acute or local infections, lack of compliance, taking into account the risks and complications: missing or limited expected postoperative functional gain, multimorbid patients with potential inoperability during the first and/or second intervention. Lateral transgluteal or posterolateral approach while protecting neurovascular and muscular structures. Preparation of the implant site based on preoperative planning with augmentation of bone defects as far as possible. Primarily stable anchoring with 2angle-stable pole screws in the ilium, an optional pole screw in the pubic bone for determination of COR, and stabilization screws in the iliac wing (optionally angle-stable). Use of dual mobility cup according to the soft tissue tension and intraoperative stability. For the first 6weeks postoperative partial weight-bearing (20 kg), followed by agradual increase of the load (10 kg per week). Between 2008 and 2018, 47patients with a Paprosky typeIII defect underwent implantation of amonoflanged CMAC. Main complication was aperiprosthetic joint infection with subsequent need for implant removal in9 of 10cases. Harris Hip Score improved from21.1 to 61.5points. X‑ray imaging displayed an angle of inclination of42.3 ± 5.3°, an anteversion of16.8 ± 6.2°, a∆ H of0.5 ± 0.2 mm and a∆ V of17.7 ± 1.1 mm according to Roessler etal.

Survival of the GAP II cage in the management of metastatic disease of the acetabulum.

The aim of this study was to assess the clinical and radiological outcomes of an antiprotrusio acetabular cage (APC) when used in the surgical treatment of periacetabular bone metastases. This retrospective cohort study using a prospectively collected database involved 56 patients who underwent acetabular reconstruction for periacetabular bone metastases or haematological malignancy using a single APC between January 2009 and 2020. The mean follow-up was 20 months (1 to 143). The primary outcome measure was implant survival. Postoperative radiographs were analyzed for loosening and failure. Patient and implant survival were assessed using a competing risk analysis. Secondary parameters included primary malignancy, oncological treatment, surgical factors, length of stay in hospital, and postoperative complications. A total of 33 patients (59%) died during the study period at a mean of 15 months postoperatively (1 to 63). No patient had radiological evidence of loosening or failure. Acetabular component survival was 100%. Three patients (5.4%) had further surgery; one (1.8%) underwent revision of the femoral component for dislocation, one required debridement with implant retention for periprosthetic joint infection, and one required closed reduction for dislocation. Using death as a competing risk, at 100 months, the probability of revision was 0.036 and the risk of death was 0.84. With appropriate patient selection, the antiprotrusio cage offers good implant survival, with a reasonable perioperative complication rate in this high-risk group of patients when managing metastatic disease or haematological malignancy around the acetabulum. Cite this article: Bone Joint J2022;104-B(4):504-509.

HSR22-159: Hip Transposition With the Use of Prophy Ethylene Mesh as a Reconstructive Option After Pelvic Resection of Periacetabular Bone Tumor: A Case Series

"HSR22-159: Hip Transposition With the Use of Prophy Ethylene Mesh as a Reconstructive Option After Pelvic Resection of Periacetabular Bone Tumor: A Case Series" published on 31 Mar 2022 by National Comprehensive Cancer Network.