Large Acetabular Bone Defects Research Articles

Bone remodeling after revision total hip arthroplasty for large acetabular defects.

Large acetabular bone defects are challenging in hip revision surgery. Clinical assessment is crucial to evaluate modern technologies in surgical reconstruction. We aimed to better understand the bone remodeling that occurs following acetabular reconstruction. Our objectives were: (1) To characterize changes in the shape of the pelvis by studying sequential computed tomography (CT) scans collected immediately and 1-year postoperatively and (2) to identify which part of the pelvis is most susceptible to remodeling. We used the CT scans taken at two timepoints, of 24 patients with acetabular bone defects classified as Paprosky IIIB, treated with three-dimensional (3D)-printed custom-made acetabular implants. Segmented 3D models of the bony pelvis were co-registered using three different techniques. A global co-registration of the full pelvis was conducted, followed by the co-registration of the innominate bone and then ilium only, on the ipsilateral reconstructed side. The relative movements of the ilium, ischium, and pubis were analyzed from visual inspection and using co-registration metrics (root mean square error and intersection over union). No bone remodeling was found in 14/24 patients (58%). The co-registration of the innominate bone indicated bone remodeling in five cases (21%), while the remaining five cases (21%) presented remodeling in the global co-registration but not the innominate bone co-registration, suggestive of changes occurring at the sacroiliac joint. Changes in the pelvic shape were greatest at the pubis and ischium. Bone remodeling may occur in complex cases of Paprosky type IIIB defects, after acetabular reconstruction (occurrence of 21%, 5/24 cases). Surgeons and engineers should consider this when monitoring implant migration.

Hip Reconstruction In Situ with Screws and Cement (HiRISC) construct to treat large acetabular bone defects.

Large bone defects resulting from osteolysis, fractures, osteomyelitis, or metastases pose significant challenges in acetabular reconstruction for total hip arthroplasty. This study aimed to evaluate the survival and radiological outcomes of an acetabular reconstruction technique in patients at high risk of reconstruction failure (i.e. periprosthetic joint infection (PJI), poor bone stock, immunosuppressed patients), referred to as Hip Reconstruction In Situ with Screws and Cement (HiRISC). This involves a polyethylene liner embedded in cement-filled bone defects reinforced with screws and/or plates for enhanced fixation. A retrospective chart review of 59 consecutive acetabular reconstructions was performed by four surgeons in a single institution from 18 October 2018 to 5 January 2023. Cases were classified based on the Paprosky classification, excluding type 1 cases (n = 26) and including types 2 or 3 for analysis (n = 33). Radiological loosening was evaluated by an orthopaedic surgeon who was not the operating surgeon, by comparing the immediate postoperative radiographs with the ones at latest follow-up. Mean follow-up was 557 days (SD 441; 31 to 1,707). Out of the 33 cases analyzed, six (18.2%) constructs required revision, with four revisions due to uncontrolled infection, one for dislocation, and one for aseptic loosening. Among the 27 non-revised constructs, only one showed wider radiolucencies compared to immediate postoperative radiographs, indicating potential loosening. Patients who underwent revision (n = 6) were significantly younger and had a higher BMI compared to those with non-revised constructs (p = 0.016 and p = 0.026, respectively). Sex, race, ethnicity, American Society of Anesthesiologists grade, infection status (patients with postoperative PJI diagnosis (septic) vs patients without such diagnosis (aseptic)), and mean follow-up did not significantly differ between revised and non-revised groups. The HiRISC technique may serve as a feasible short-term (about one to two years) alternative in patients with large acetabular defects, particularly in cases of PJI. Longer follow-up is necessary to establish the long-term survival of this technique.

Hip joint center lateralization minimally affects the biomechanics of patient-specific flanged acetabular components: A computational model.

Patient-specific flanged acetabular components are utilized to treat failed total hip arthroplasties with large acetabular defects. Previous clinical studies from our institution showed that these implants tend to lateralize the acetabular center of rotation. However, the clinical impact of lateralization on implant survivorship is debated. Our goal was to develop a finite element model to quantify how lateralization of the native hip center affects periprosthetic strain and implant-bone micromotion distributions in a static level gait loading condition. To build the model, we computationally created a superomedial acetabular defect in a computed tomography 3D reconstruction of a native pelvis and designed a flanged acetabular implant to address this simulated bone defect. We modeled two implants, one with ~1 cm and a second with ~2 cm of hip center lateralization. We applied the maximum hip contact force and corresponding abductor force observed during level gait. The resulting strains were compared to bone fatigue strength (0.3% strain) and the micromotions were compared to the threshold for bone ingrowth (20 µm). Overall, the model demonstrated that the additional lateralization only slightly increased the area of bone at risk of failure and decreased the areas compatible with bone ingrowth. This computational study of patient-specific acetabular implants establishes the utility of our modeling approach. Further refinement will yield a model that can explore a multitude of variables and could be used to develop a biomechanically-based acetabular bone loss classification system to guide the development of patient-specific implants in the treatment of large acetabular bone defects.

Cementing a Monoblock Dual-Mobility Implant into a Fully Porous Cup in Revision Total Hip Arthroplasty to Address Hip Instability: Surgical Technique.

Cementing a Monoblock Dual-Mobility Implant into a Fully Porous Cup in Revision Total Hip Arthroplasty to Address Hip Instability: Surgical Technique.

VIRTUAL BIOMECHANICAL ASSESSMENT OF CUSTOM TRIFLANGE AND TRABECULAR METAL COMPONENTS TO TREAT LARGE ACETABULAR DEFECTS

The best treatment method of large acetabular bone defects at revision THR remains controversial. Some of the factors that need consideration are the amount of residual pelvic bone removed during revision; the contact area between the residual pelvic bone and the new implant; and the influence of the new acetabular construct on the centre of rotation of the hip. The purpose of this study was to compare these variables in two of the most used surgical techniques used to reconstruct severe acetabular defects: the trabecular metal acetabular revision system (TMARS) and a custom triflanged acetabular component (CTAC).Pre- and post-operative CT-scans were acquired from 11 patients who underwent revision THR with a TMARS construct for a Paprosky IIIB defect, 10 with pelvic discontinuity, at Royal Adelaide Hospital. The CT scans were used to generate computer models to virtually compare the TMARS and CTAC constructs using a semi-automated method. The TMARS construct model was calculated using postoperative CT scans while the CTAC constructs using the preoperative CT scans. The bone contact, centre of rotation, inclination, anteversion and reamed bone differences were calculated for both models.There was a significant difference in the mean amount of bone reamed for the TMARS reconstructions (15,997 mm3) compared to the CTAC reconstructions (2292 mm3, p>0.01). There was no significant difference between overall implant bone contact (TMARS 5760mm2 vs CTAC 5447mm2, p=0.63). However, there was a significant difference for both cancellous (TMARS 4966mm2 vs CTAC 2887mm2, p=0.008) and cortical bone contact (TMARS 795mm2 vs CTAC 2560mm2, p=0.001). There was no difference in inclination and anteversion achieved. TMARS constructs resulted on average in a centre of rotations 7.4mm more lateral and 4.0mm more posterior.Modelling of two different reconstructions of Paprosky IIIB defects demonstrated potential important differences between all variables investigated.

Revision Total Hip Arthroplasty Utilizing an Acetabular Reinforcement Ring with a Metal Augment: A Minimum Eight-Year Follow-Up Study.

Background and Objectives: An acetabular reinforcement ring (ARR) with a structural allograft is conventionally used to treat large acetabular bone defects or discontinuity during revision hip arthroplasty. However, ARR is prone to failure due to bone resorption and lack of incorporation. Here, we investigated the surgical outcomes of the patients who underwent revision total hip arthroplasty (THA) using ARR combined with a metal augment (MA). Materials and Methods: We retrospectively reviewed data from 10 consecutive patients who had a minimum 8-year follow-up after revision hip arthroplasty using ARR with MA in Paprosky type III acetabular defect. We collected patient demographics, surgical details, clinical scores (including Harris Hip Score (HHS)), postoperative complications, and 8-year survival rates. Results: Six male and four female patients were included. The mean age was 64.3 years, and the mean follow-up duration was 104.3 months (96.0-112.0 months). Trauma-related diagnosis was the most common reason for index surgery. Three patients underwent all component revision, and seven underwent cup revision. Six were confirmed as Paprosky type IIIA and four as type IIIB. The mean HHS at the final follow-up was 81.5 (72-91). One patient was diagnosed with prosthetic joint infection at the 3-month follow-up; therefore, the minimum 8-year survival rate with our technique was 90.0% (95% confidence interval, 90.3-118.5%). Conclusions: The satisfactory mid- to long-term results of revision THA suggest that ARR combined with tantalum MA is a viable revision option for treating severe acetabular defects with pelvic discontinuity.

Biphasic bone graft substitute in revision total hip arthroplasty with significant acetabular bone defects

Large acetabular bone defects encountered in revision total hip arthroplasty (THA) are challenging to restore. Metal constructs for structural support are combined with bone graft materials for restoration. Autograft is restricted due to limited volume, and allogenic grafts have downsides including cost, availability, and operative processing. Bone graft substitutes (BGS) are an attractive alternative if they can demonstrate positive remodelling. One potential product is a biphasic injectable mixture (Cerament) that combines a fast-resorbing material (calcium sulphate) with the highly osteoconductive material hydroxyapatite. This study reviews the application of this biomaterial in large acetabular defects. We performed a retrospective review at a single institution of patients undergoing revision THA by a single surgeon. We identified 49 consecutive patients with large acetabular defects where the biphasic BGS was applied, with no other products added to the BGS. After placement of metallic acetabular implants, the BGS was injected into the remaining bone defects surrounding the new implants. Patients were followed and monitored for functional outcome scores, implant fixation, radiological graft site remodelling, and revision failures. Mean follow-up was 39.5 months (36 to 71), with a significant improvement in post-revision function compared to preoperative function. Graft site remodelling was rated radiologically as moderate in 31 hips (63%) and strong in 12 hips (24%). There were no cases of complete graft site dissolution. No acetabular loosening was identified. None of the patients developed clinically significant heterotopic ossification. There were twelve reoperations: six patients developed post-revision infections, three experienced dislocations, two sustained periprosthetic femur fractures, and one subject had femoral component aseptic loosening. Our series reports bone defect restoration with the sole use of a biphasic injectable BGS in the periacetabular region. We did not observe significant graft dissolution. We emphasize that successful graft site remodelling requires meticulous recipient site preparation.Cite this article: Bone Jt Open2022;3(12):991-997.

Constrained acetabular liners are a viable option in second-stage re-implantation for chronic infected total hip arthroplasty with abductor or greater trochanter deficiency and large acetabular bone defects

BackgroundAbductor mechanism deficiency is a clear indication for using constrained acetabular liners (CALs), and large acetabular bone defects are considered a relative contraindication to CALs. We report the results of using CALs in special cases in which abductor or greater trochanter deficiency was accompanied by large acetabular bone defects at second-stage re-implantation for chronic infected total hip arthroplasty (THA).MethodsBetween January 2010 and January 2018, 19 patients who used CALs at second-stage re-implantation and had abductor or greater trochanter deficiency and large acetabular bone defects were included in this study. We followed up with the clinical and radiological results of these patients. Complications and infection-related information were also recorded.ResultsEight patients, 4 patients, and 7 patients had Paprosky type IIB, type IIC, and type IIIA acetabular bone defects at second-stage re-implantation, respectively. The indication for using CALs was abductor deficiency in 14 patients and greater trochanter deficiency in the other 5 patients. The mean follow-up was 74.4 months (range 50–96). The mean Harris Hip Score (HHS) was 76.3 points (range 62–86) at the last follow-up. Three patients presented acetabular radiolucent lines with no progress: zone 3, zone 3 and zone 2 and 3, respectively. One patient suffered transient sciatic nerve palsy. There was no dislocation, failure of the CALs, reoperation, or recurrence of infection.ConclusionOur results suggested that for screened patients, CALs are a viable option in second-stage re-implantation for chronic infected THA with abductor or greater trochanter deficiency and large bone defects.

Use of Customized 3D-Printed Titanium Augment With Tantalum Trabecular Cup for Large Acetabular Bone Defects in Revision Total Hip Arthroplasty: A Midterm Follow-Up Study.

Aims: In revision total hip arthroplasty (THA), large acetabular bone defects pose challenges for surgeons. Recently, wide application of trabecular tantalum, which has outstanding biocompatibility and mechanical properties, and the development of three-dimensional (3D) printing have led to the introduction of new schemes for acetabular reconstruction. However, few studies have focused on the treatment of bone defects with customized 3D-printed titanium augments combined with tantalum trabecular cup. Thus, we aimed to evaluate the effect of this therapy in patients who underwent revision THAs. Patients and Methods: We included 23 patients with Paprosky type III acetabular bone defects who underwent revision THA between January 2013 and June 2019. The preoperative hip rotation center and functional score were compared with those at 2–7 years (average 4.7 years) postoperatively to evaluate the midterm prognosis of our treatment choice. Results: Postoperatively, the rotation centres of all hips were comparable with those of the contralateral hips. Hip function improved with average Harris Hip Score improved from 33.5 (22.7–40.2) to 86.1 (73.5–95.6) and average Oxford Hip Score improved from 8.3 (0–14) to 38.8 (35–48) during follow-up. One dislocation, which occurred due to extreme hip flexion within 6 weeks, was treated with closed reduction, and no recurrent dislocation occurred. No nerve injury, infection, aseptic loosening, or osteolysis were observed and no re-revision was performed in any patient. Conclusion: Satisfactory midterm outcomes were obtained with 3D-printed titanium augment combined with tantalum cup for the treatment of acetabular defects in revision THA. Changes in the Harris Hip Score and Oxford Hip Score suggested a significant improvement in hip function.

3D Printing Hip Prostheses Offer Accurate Reconstruction, Stable Fixation, and Functional Recovery for Revision Total Hip Arthroplasty with Complex Acetabular Bone Defect

Complicated and large acetabular bone defects present the main challenges and difficulty in the revision of total hip arthroplasty (THA). This study aimed to explore the advantages of three-dimensional (3D) printing technology in the reconstruction of such acetabular bone defects. We retrospectively analyzed the prognosis of four severe bone defects around the acetabulum in three patients who were treated using 3D printing technology. Reconstruction of bone defect by conventional methods was difficult in these patients. In this endeavor, we used radiographic methods, related computer software such as Materialise's interactive medical image control system and Siemens NX software, and actual surgical experience to estimate defect volume, prosthesis stability, and installation accuracy, respectively. Moreover, a Harris hip score was obtained to evaluate limb function. It was found that bone defects could be adequately reconstructed using a 3D printing prosthesis, and its stability was reliable. The Harris hip score indicated a very good functional recovery in all three patients. In conclusion, 3D printing technology had a good therapeutic effect on both complex and large bone defects in the revision of THA. It was able to achieve good curative effects in patients with large bone defects.

Cup-Cage Solution for Massive Acetabular Defects: A Systematic Review and Meta-Analysis.

Our systematic review compiled multiple studies and evaluated survivorship and clinical outcomes of cup‐cage construct usage in the management of massive acetabular bone defects. This systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses (PRISMA) guidelines. Various combinations of “acetabular”, “pelvis”, “cup cage” and their corresponding synonyms were used to search relevant articles in the Cochrane, EMBASE, and PubMed databases. Basic information of the functional scores, implant revision rate, and complication rate were selected as outcomes for analysis. Finally, a total of 11 articles published between 1999 and 2019 were selected, which include 232 patients with an average age of 68.5 years (range, 30–90). The mean follow‐up period was 48.85 months (range, 1–140). Our study shows that the cup‐cage construct has a good clinical outcome with a low revision rate and a low complication rate. Improved clinical outcomes of cup‐cage constructs were seen with a revision rate of 8% and an all‐cause complication rate of 20%. The most commonly reported complication was dislocation, followed by aseptic loosening, infection, and nerve injuries. In summary, it is a promising method for managing large acetabular bone defects in total hip revision.

Acetabular revision arthroplasty with anovel cementless augment-and-modular-cage system (MRS-C) : Surgical technique and preliminary clinical results

Optimal reconstruction of acetabular anatomy and primarily stable bridging even of large bone defects in hip revision surgery by intraoperative cementless application of highly modular components of the MRS-TITAN Comfort (MRS-C) system according to the augment-and-modular-cage principle. Acetabular defect situations in hip revision surgery, hereditary/acquired acetabular deformities, severe secondary hip osteoarthritis. Extended periacetabular defects of the dorsal pillar, pelvic discontinuities, persisting posttraumatic or periprosthetic infections, lack of intraoperative bony anchorage options. Conventional positioning. Flexible selection of approach (posterolateral, anterolateral or transgluteal) to the hip joint, if possible using aprevious approach. Implant removal, preparation and intraoperative acetabular defect evaluation. Optional impaction bone grafting for biological downsizing. Selection of modular components and augments depending on the defect. Preparation of the obturator foramen for anchorage of the caudal flange. Optional preparation of the os ilium for additional fixation of the cage with flanges. Fixation with polyaxial screws and selection of version/inclination of the cup component. Selection of the inlay (polyethylene/ceramic). Partial weight-bearing with 20 kg body-weight for 6weeks with crutches. Prophylaxis for deep vein thrombosis and heterotopic ossification. Additional adapted antibiotic therapy in cases of infection. Aminimum 1‑year follow-up of 42patients showed significant improvements of Harris Hip Scores (p < 0.0001), adequate reconstruction of the physiologic center of rotation (x-ray controlled in the vertical plane, referenced to the contralateral side), and aclear reduction of preoperative leg length discrepancies. No significant changes in range of motion. No implant-associated complications noted. Based on the short follow-up results, the implant proves as suitable for reconstruction of even large acetabular bone defects.

Radiographic evaluation of 19 patients with Paprosky 3A and 3B submitted to acetabular review with trabecular metal wedge

ObjectiveThis study is aimed at evaluating the fixation of trabecular metal wedges in patients who underwent revision of total hip arthroplasty with large acetabular bone defects. MethodsThe radiographs of 19 patients (21 hips), who underwent revision of total hip arthroplasty using trabecular metal wedges from September 2010 to December 2014 were evaluated. This study included only cases of Paprosky 3A and 3B. Preoperative and postoperative images were analyzed. Non-fixation of the implant was defined by the presence of angular variation of the component higher 10 degrees or displacement greater than 6mm. Patients with follow-up times of less than 24 months or who did not attend the last two appointments were excluded from the study. ResultsThe mean follow-up time was 39.4 months (25–61). Fixation was achieved in all cases despite its complexity. There was only one case of dislocation that was treated with open reduction. One case developed infection, and was surgically approached on two occasions, with extensive debridement and intravenous antibiotics following protocol, with good evolution. ConclusionThe implanted trabecular metal wedges showed excellent results in the short- and medium-term and may represent another option in the reconstruction of large acetabular defects, sometimes replacing bone reconstruction that uses bone tissue banks or autologous graft.

Avaliação radiográfica de 19 pacientes Paprosky 3 A e 3 B submetidos à revisão acetabular com cunha de metal trabeculado

ObjectiveThis study is aimed at evaluating the fixation of trabecular metal wedges in patients who underwent revision of total hip arthroplasty with large acetabular bone defects. MethodsThe radiographs of 19 patients (21 hips), who underwent revision of total hip arthroplasty using trabecular metal wedges from September 2010 to December 2014 were evaluated. This study included only cases of Paprosky 3A and 3B. Preoperative and postoperative images were analyzed. Non fixation of the implant was defined by the presence of angular variation of the component higher 10 degrees or displacement greater than 6mm. Patients with follow‐up times of less than 24 months or who did not attend the last two appointments were excluded from the study. ResultsThe mean follow‐up time was 39.4 months (25‐61). Fixation was achieved in all cases despite its complexity. There was only one case of dislocation that was treated with open reduction. One case developed infection, and was surgically approached on two occasions, with extensive debridement and intravenous antibiotics following protocol, with good evolution. ConclusionThe implanted trabecular metal wedges showed excellent results in the short‐ and medium‐term and may represent another option in the reconstruction of large acetabular defects, sometimes replacing bone reconstruction that uses bone tissue banks or autologous graft.

Virtual anatomical reconstruction of large acetabular bone defects using a statistical shape model

Custom implants are used to treat patients with large acetabular bone defects. To quantify the bone defect and to initialize the implant design, a virtual anatomical reconstruction of the bone needs to be performed. Our SSM-based reconstruction approach was used to overcome the limitations of the mirrored contralateral method and improves upon other SSM reconstruction techniques. The reconstruction errors for the acetabular direction, the hip joint center and the acetabular radius were, respectively: , 2.6 mm and 0.7 mm. We believe that our method can be an essential tool in the planning and the design of custom implants.

A 2- to 7-Year Follow-Up of a Modular Iliac Screw Cup in Major Acetabular Defects: Clinical, Radiographic and Survivorship Analysis With Comparison to the Literature

BackgroundInadequate acetabular bone stock is a major issue in total hip arthroplasty, and several treatment options are available. Stemmed cups have been used in this scenario with variable results. A novel modular polyaxial uncemented iliac screw cup (HERM-BS–Sansone cup—Citieffe s.r.l., Calderara di Reno, Bologna, Italy) has been recently introduced to overcome the drawbacks of stemmed cups. In this retrospective study, we report the results of this cup in patients with large acetabular bone defects at 2- to 7-year follow-up. MethodsWe evaluated a consecutive series of 121 hips (118 revisions and 3 complex primary arthroplasties) treated with this novel cup at a mean follow-up of 46 months. Kaplan–Meier survival analysis was performed with implant revision for any reason as a primary end point. Further survival analysis was performed excluding septic failures. Clinical outcome was assessed with the Harris Hip Score. ResultsThere had been 7 reoperations: 1 for aseptic loosening, 5 for deep infection, and 1 for recurrent dislocation. In 5 cases, the cup was removed; estimated survival rate at 5-year follow-up with implant removal for any reason was 95.6% (95% confidence interval = 91-99), and 98.3% (95% CI = 96-100) excluding those failed for infection. Mean Harris Hip Score at latest follow-up was 77 points (range, 44-95; standard deviation = 11.9). ConclusionThe present findings show the short-term efficacy of the iliac screw cup with respect to implant survival. A longer follow-up and a larger number of patients are necessary to confirm the encouraging preliminary results.

Highly porous metal shells and augments in revision hip surgery: Big hopes for big holes

Incidence of total hip revision surgery is increasing with acetabular failure being the most common cause of revision, with or without loosening of the shell. Acetabular defects at time of surgery can be challenging to treat and different techniques have been described with no clear consensus on the best modality. Trabecular metal implants, and especially the use of augments provide a unique option to manage these conditions efficiently with less morbidity, improved function and better survivability. Previous literature has suggested that the survival of this combination (trabecular metal revision shell and augment) is around 94–100% at 2 years, 92–100% at 5 years and 92% at 10 years with revision due to aseptic loosening as an end-point. We hence recommend continued the use of trabecular metal shells and augments for managing large acetabular bone defects found during revision hip arthroplasty.

The value of bulk femoral head allograft in acetabular reconstruction using Kerboull-type plate.

This study investigated the mid- and long-term results of acetabular reconstruction using a KT plate with an allograft and showed the utility of filling the bony defect with bulk femoral head allograft rather than morselised allograft. We retrospectively investigated a consecutive series of 31 hips in 30 patients who underwent primary THA or revision THA between March 2002 and March 2012. Bulk grafts from femoral head allografts were used in 16 hips and morselised grafts were used in 15 hips. The mean follow-up period was 7.2 years (3-13 years). The acetabular bone defects were classified according to the American Academy of Orthopedic Surgeons grading system. Type II defects were present in five hips; 26 hips were type III. Radiological failure, defined as absolute error of the inclination of the KT plate >3°, breakage of the KT plate or screw, and/or absolute error of the vertical or horizontal migration of the femoral head >3 mm was found in 12 cases. All these complications appeared in the morselized group; there were no complications in the bulk group. The eight-year survival rate of morselised grafts was 52.5% and that of bulk grafts was 100%, using radiological loosening as an end point. We conclude that using bulk graft from femoral head allografts is necessary to achieve mechanically stable reconstruction for large acetabular bone defects.

Harnblasenperforation durch Migration eines Burch-Schneider-Stützrings

Reinforcement cages are widely used for the treatment of large acetabular bone defects. We report the case of a loosened Burch-Schneider reinforcement ring causing a recurrent macrohaematuria due to a perforation of the urinary bladder. After performing several diagnostic procedures, the patient underwent interdisciplinary revision surgery. Due to the severe destruction of the acetabular bone stock and an infection of the total hip prosthesis as confirmed by fresh frozen section, the hip prosthesis was explanted. At the last follow-up the patient was free of infect-related symptoms and was able to walk with one crutch.

Papers Presented at the Hip Society Meetings 2008: Editorial Comment

The 2008 symposium of Proceedings of the Hip Society provides a wide-ranging mixture of issues relevant to hip surgery. These manuscripts represent topics presented and discussed at the 2007 Annual Closed Fall Meeting held in Pasadena, California and the 2008 Open Scientific Winter Meeting in San Francisco, California as organized by Lawrence D. Dorr, MD and myself. The classic paper by Merle d’Aubigne is a particularly interesting manuscript that is a very enjoyable study and should be read by all surgeons currently involved with hip arthroplasty. Readers might not be aware Merle d’Aubigne and his colleagues proposed not one, but three scoring systems: one in English and two in French. These differences are explained in the accompanying biosketch. As might be expected, new topics this year included papers on computer navigation systems for the hip and reports on the resurgence of hip resurfacing. In particular, the resurfacing papers focus on the importance of patient selection, surgical technique, and revision of failed resurfacing procedures. Several manuscripts related to long-term followup of cementless femoral components provide the baseline of performance expected with modern hip arthroplasty as we receive more information on the outcomes of resurfacing. The remainder of the symposium focuses on a large variety of topics related to surgical techniques and prosthetic design to optimize component position and avoid prosthetic impingement and optimal fixation. Additional topics included wear analysis with ceramic on crosslinked polyethylene, the presence of metal ions following metal-on-metal hip replacement, and the assessment of osteolysis by computed tomography. There were many papers on acetabular and femoral failures which included a previously unreported failure mode related to the use of lateralized acetabular liners. Acetabular revision techniques for isolated acetabular polyethylene exchange and the treatment of large acetabular bone defects and treatment of severe femoral bone loss are included. A paper on why revision hip arthroplasties fail yet again is particularly interesting. Finally, a group of papers describing perioperative complications of early mortality, deep periprosthetic infection, and treatment of periprosthetic femoral fractures completes the broad spectrum of topics for readers of this year’s symposium.