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Background: Chronic pelvic discontinuity is a challenge during revision total hip arthroplasty due to the loss of structural continuity of the superior and inferior aspects of the acetabulum from severe acetabular bone loss. Acetabular distraction provides an alternative surgical treatment by stabilizing the acetabular component through elastic recoil of the pelvis, which may be supplemented with modular porous augments for addressing major acetabular defects. This study reports 2-year radiographic findings following acetabular distraction for the treatment of chronic pelvic discontinuity., Methods: Patients undergoing acetabular distraction performed by 5 surgeons from 2002 to 2021 were identified across 5 institutions. Demographic, surgical, and postoperative outcomes, including radiographic component stability, were recorded. There were 53 of 91 (58.2%) patients (5 deceased, 33 lost to follow-up) consisting of 4 Paprosky IIC (7.5%), 8 Paprosky IIIA (15.1%), and 41 Paprosky IIIB (77.4%) defects included, with a mean follow-up time of 4.8 years (range, 2 to 13.5). Modular porous augments were used in 33 (62.3%) cases. Failure was defined as a subsequent revision of the acetabular construct., Results: Among the 13 (24.5%) patients who returned to the operating room, 6 (46.2%) had a prior history of revision total hip arthroplasty before undergoing acetabular distraction. Only 5 (9.4%) patients underwent acetabular revision following acetabular distraction, leading to an overall cup survivorship of 90.6%. Of the remaining 48 patients, 46 (95.8%) had evidence of radiographic bridging callus of the chronic pelvic discontinuity at their last clinical follow-up., Conclusions: To our knowledge, in the largest series to date, acetabular distraction has proven to be a viable treatment for acetabular bone loss with a chronic pelvic discontinuity, with excellent early survivorship and radiographic evidence of bridging callus. Future studies with longer follow-ups are needed to further monitor the efficacy of this technique., Level of Evidence: Level III, Retrospective Comparative Study., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Severe acetabular bone loss encountered during revision total hip arthroplasty (THA) poses a clinical challenge. In cases involving pelvic discontinuity, where the ilium is separated superiorly from the inferior ischiopubic segment through the acetabulum, acetabular distraction may be used to restore the biomechanics of the hemipelvis. This technique allows for correct sizing of the acetabulum, and the subsequent peripheral distraction and medial compression at the discontinuity provide initial mechanical stability and biological fixation as bone in growth occurs. Accordingly, this study aimed to assess long-term 5-year outcomes following acetabular distraction across 2 institutions., Methods: We retrospectively identified all patients who underwent revision THA in which the acetabular distraction technique was performed for the treatment of chronic pelvic discontinuity between 2002 and 2018. Demographic, operative, and clinical postoperative data were collected. Clinical endpoints included postoperative radiographic outcomes, complications requiring additional surgery, and reoperation for all causes. Only patients who had a minimum 5-year follow-up were included in this study., Results: A total of 15 patients (Paprosky IIC: one patient, 6.7%; Paprosky IIIA: 5 patients, 33.3%; Paprosky IIIB: 9 patients, 60%) who had a mean follow-up time of 9 years (range, 5.1 to 13.5) were analyzed. Porous tantalum augments were used in 11 (73.3%) cases to primarily address posteriorsuperior defects (100%). There were 4 (26.7%) patients that required reoperation, only 2 of which were for indications related to the acetabular construct, leading to an overall survivorship of 86.7%. Both patients had a prior revision THA before the implementation of the distraction technique. Evidence of bridging callus formation was reported radiographically for 14 (93.3%) patients at the time of the last clinical follow-up., Conclusions: For patients who have chronic pelvic discontinuity, acetabular distraction shows promising long-term outcomes. Even so, larger multi-center studies are needed to better support the efficacy of this technique., Level of Evidence: Level III, retrospective comparative study., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Acetabular bone loss continues to be one of the most complex and challenging scenarios facing the orthopaedic surgeon. Preoperative planning and classification systems essentially have remained the same, with the Paprosky classification still being the most commonly used. Careful radiological assessment with well-defined criteria can accurately diagnose acetabular bone loss patterns with an associated chronic pelvic discontinuity before surgery. The use of cemented reconstruction techniques has declined, and contemporary practice trends have involved the increasing use of highly porous hemispherical shells in conjunction with modular porous metal augments, which can successfully treat most acetabular revisions. Noncemented treatment options for the management of acetabular bone loss during revision include conventional porous/modular highly porous hemispherical implants, nonmodular highly porous implants with cementable acetabular liners, cup-cage reconstruction, oblong cups, and triflange reconstruction. These options can be combined with modular porous metal augments, structural allografts, impaction grafting, or reconstruction cages. Acetabular distraction is a newer technique for chronic pelvic discontinuity, which is used in conjunction with off-the-shelf revision acetabular shells and modular porous metal augments. This review is an update over the past decade, highlighting studies with mid to long-term follow-up, and presents the advantages, disadvantages, and principles associated with each of the most commonly used reconstructive techniques., (Copyright © 2024 by the American Academy of Orthopaedic Surgeons.)

As indications for total hip arthroplasty (THA) continue to expand, and patients continue to live longer with more active lifestyles, the incidence of revision THA is expected to rise. General orthopaedic surgeons are now beginning to consider doing revision THA surgery because of the increased revision burden being experienced nationwide. While classical approaches to the hip can be used for simple revisions, extensile exposure techniques in conjunction with selective soft-tissue releases are often required for adequate visualization for more complex revision cases. This review provides a systematic approach to surgical exposure for revision THA using the posterior approach. The surgeon should follow a stepwise progression to obtain safe, adequate, and reproducible visualization of both the acetabulum and the proximal femur., (Copyright © 2023 by the American Academy of Orthopaedic Surgeons.)

Background: Anteroposterior (AP) pelvic radiographs are subject to errors that may cause measurement inaccuracy in total hip arthroplasty (THA). Such errors may be detected by measuring pre- to postoperative leg-length changes in the nonoperative leg, which experiences no physical changes during THA., Methods: From AP pelvic radiographs, we measured pre- to postoperative leg-length changes (LLC) in the nonoperative legs of 67 patients who underwent primary THA using the trans-ischial line method., Results: An LLC of 0 mm was observed in the nonoperative leg in only 14 cases (21%). A LLC ⩾ 2 mm was observed in 27% (18/67) of cases, including 13% (9/67) with LLC ⩾ 3 mm and 6% (4/67) with LLC ⩾ 4 mm. A post-hoc analysis used a validated method to measure change in pelvic tilt between pre- and postoperative images and found that changes in pelvic tilt ⩾ 4° in the anterior and posterior directions created apparent lengthening (2.0 ± 1.4 mm, p   <  0.001 vs. 0-3° of tilt) and shortening (-2.1 ± 1.6 mm, p   <  0.001 vs. 0-3° of tilt) of the nonoperative leg, respectively., Conclusions: The current study provides evidence of measurement errors in leg length using AP pelvic radiographs following THA. Changes in pelvic tilt may be in part responsible for these errors, with the direction of change in pelvic tilt influencing the apparent lengthening or shortening of the lower limb. Ultimately, these findings may influence the radiographic measurement and interpretation of leg-length changes following THA.

Acetabular bone loss continues to be a challenging clinical problem faced by the revision total hip arthroplasty surgeons. The presence of a chronic pelvic discontinuity further complicates this clinical entity. Several surgical techniques have been described for the management of severe acetabular bone loss with an associated chronic pelvic discontinuity, with increasing enthusiasm for noncemented reconstruction. The focus is on noncemented reconstruction of Paprosky type IIIB acetabular defects with a chronic pelvic discontinuity.

»: Appropriate total hip arthroplasty (THA) reconstruction must simultaneously address component position, restoration of biomechanics, and soft-tissue balance., »: Preoperative planning for complex THA cases should include radiographic templating, a detailed case plan that contains backup implant options, and a thorough understanding of the patient's preoperative examination., »: Using a systematic approach to soft-tissue balancing in THA enhances the ability to intraoperatively execute the preoperative plan., »: In patients with preexisting deformities (e.g., dysplasia or prior surgery), increased attention to abductor function is necessary when assessing acetabular component placement and offset., Competing Interests: Disclosure: No external funds were received in support of this work. On the Disclosure of Potential Conflicts of Interest forms, which are provided with the online version of the article, one of more o the authors checked “yes” to indicate that the author had a relevant financial relationship in the biomedical arena outside the submitted work (http://links.lww.com/JBJSREV/A668)., (Copyright © 2021 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: Mechanically assisted crevice corrosion (MACC) at modular junctions can cause a spectrum of adverse local tissue reactions (ALTRs) in patients who have undergone total hip arthroplasty (THA). The purpose of this study is to describe the presentation, treatments, and related complications of a cohort of patients presenting with late instability following metal-on-polyethylene THA due to underlying MACC and ALTR., Methods: This multicenter retrospective case series presents 17 patients (12 women, mean age 62.6, range 42-73) presenting with late instability secondary to ALTR and MACC. All patients had a metal (Cobalt Chrome)-on-polyethylene bearing surface. Patients experienced a mean 2.7 dislocations (range 1-6) at mean 4.3 years (range 0.4-17.0) following their index surgery. Serum metal levels (n = 12) demonstrated a greater elevation of cobalt (mean 6.9, range 0.13-20.88 ng/mL) than chromium (mean 1.9, range 0.13-3.23 ng/mL)., Results: Patients were revised for instability at a mean of 6.8 years (range 2.1-19.4) following their index surgery. ALTR was encountered in every case and the modular head-neck junction demonstrated visible corrosion. An exchange of the CoCr head to a ceramic head with a titanium sleeve and placement of a constrained liner was performed for a majority of patients (n = 15, 88.2%). Five patients (29.4%) had complications postoperatively including peroneal palsy (n = 2), periprosthetic joint infection (n = 2), and ALTR recurrence (n = 1)., Conclusion: Recurrent instability in the setting of otherwise well-positioned THA components and without another obvious cause should raise concern for ALTR as a potential underlying etiology., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Previous reports on the outcomes of isolated head and liner exchange in revision total hip arthroplasty have found high rates of instability after these surgeries. Most reports have studied constructs using ≤28 mm femoral heads. The purpose of this study was to determine if modern techniques with the use of larger head sizes can improve the rate of instability after head and liner exchange., Methods: We identified 138 hips in 132 patients who underwent isolated head and liner exchange for polyethylene wear/osteolysis (57%), acute infection (27%), metallosis (13%), or other (2%). All patients underwent revision with either 32 (23%), 36 (62%), or 40 (15%) mm diameter heads. Cross-linked polyethylene was used in all revisions. Lipped and/or offset liners were used in 104 (75%) hips. Average follow-up was 3.5 (1.0-9.1) years. Statistical analyses were performed with significance set at P < .05., Results: Revision-free survivorship for any cause was 94.6% and for aseptic causes was 98.2% at 5 years. 11 (8%) hips experienced a complication with 7 (5%) hips requiring additional revision surgery. After revision, 4 (3%) hips experienced dislocation, 5 (4%) hips experienced infection, and 1 (1%) hip was revised for trunnionosis. No demographic or surgical factors significantly affected outcomes., Conclusion: Our study shows that isolated head and liner exchange using large femoral heads and modern liners provides for better stability than previous reports. The most common complication was infection. We did not identify specific patient, surgical, or implant factors that reduced the risk of instability or other complication., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Acetabular bone loss, and specifically when it is associated with a chronic pelvic discontinuity, presents a difficult clinical challenge at the time of revision total hip arthroplasty. Most centers have advocated the use of noncemented constructs in an effort to achieve biologic fixation. The authors prefer noncemented fixation with use of the acetabular distraction technique in conjunction with modular porous metal augments for the treatment of severe acetabular bone loss and an associated chronic pelvic discontinuity.

Introduction: Identifying the source of pain is paramount for determining appropriate treatment and ensuring successful outcome in terms of management and relief of pain. The difficulty is that each surgeon has his or her own way of seeing the problem, and there is no consensus for the evaluation of these patients. The study hypothesis was that it is possible to find the cause of the pain in most cases., Patients and Methods: All patients consulting for unexplained painful hip arthroplasty were included and followed a decision tree to assess the cause of the pain. The primary endpoint was the final diagnosis. Secondary endpoints were subgroup comparison between main causes and assessment of risk factors., Results: Two hundred one hips of 194 patients were included as unexplained painful hip arthroplasty 6 months postoperatively. Final diagnoses comprised periarticular pain in 53 cases (26.4%): 40 cases of trochanteric bursitis, 5 of iliopsoas tendinitis, 5 of abductor deficiency, 1 of ischial tuberosity tendinitis, and 2 of heterotopic ossification; projected pain in 49 (24.4%): 45 cases of back pain with or without neuropathy, 3 of knee osteoarthritis, and 1 of metabolic neuropathy; wear in 40 (19.9%), in the polyethylene liner; loosening in 20 (10.0%): loosening of the femoral component in 8 and that of the cup in 12; material problems in 17 (8.5%): trunnionosis in 13 and metallosis in metal-on-metal implants in 4; no diagnosis in 7 hips (3.5%); infection in 6 (3.0%), all chronic; instability without real dislocation in 3 (1.5%); misplacement in 3 (1.5%), all for leg-length discrepancy; fracture in 2 (1.0%): 1 of greater trochanter and 1 of ilio-ischiopubic ramus; complex regional pain syndrome in 1 (0.5%)., Discussion: To our knowledge, this is the first study on the causes of painful hip arthroplasty in clinical practice, whether leading to revision or not. A systematic approach, including physical examination, radiographic assessment and laboratory studies, is needed to find the cause of the pain. It is important to understand the pain so that it can be treated appropriately. Revision surgery can sometimes help-but the worst thing is to make the patient worse., Level of Evidence: level 4, retrospective study., (Copyright © 2019 Elsevier Inc. All rights reserved.)

As the demand for total hip arthroplasty (THA) continues to increase, the burden of revision THA is also expected to increase. Although the quality of polyethylene has improved markedly, osteolysis continues to be a risk for older designs and younger, active patients. Although progressive but typically asymptomatic in early stages, osteolysis can result in component failure and complicate revision surgery. Serial radiographs are paramount for monitoring progression. Although select cases may be treated with observation, surgery should be considered based on age, activity level, and projected life span. Well-fixed, noncemented modular acetabular components may be treated with curettage and bone grafting, as well as having to bear liner exchange with retention of the acetabular shell. However, in the setting of osteolysis, it is controversial whether bone grafting and component retention is superior to cup revision. This review explores the pathophysiology of osteolysis after THA and provides a comprehensive analysis of the evaluation and treatment of patients with osteolysis.

Aims The aim of this study was to examine the results of the acetabular distraction technique in achieving implantation of a stable construct, obtaining biological fixation, and producing healing of chronic pelvic discontinuity at revision total hip arthroplasty. Patients and Methods We identified 32 patients treated between 2006 and 2013 who underwent acetabular revision for a chronic pelvic discontinuity using acetabular distraction, and who were radiographically evaluated at a mean of 62 months (25 to 160). Of these patients, 28 (87.5%) were female. The mean age at the time of revision was 67 years (44 to 86). The patients represented a continuous series drawn from two institutions that adhered to an identical operative technique. Results Of the 32 patients, one patient required a revision for aseptic loosening, two patients had evidence of radiographic loosening but were not revised, and three patients had migration of the acetabular component into a more stable configuration. Radiographically, 22 (69%) of the cohort demonstrated healing of the discontinuity. The Kaplan-Meier construct survivorship was 83.3% when using revision for aseptic acetabular loosening as an endpoint. At the time when one patient failed due to aseptic loosening (at 7.4 years), there were a total of seven patients with a follow-up of seven years or longer who were at risk of failure. Conclusion The acetabular distraction technique demonstrates encouraging radiographic outcomes, with healing of the discontinuity in over two-thirds of our series. This surgical technique permits biological fixation and intraoperative customization of the construct to be implanted based on the pattern of the bone loss identified following component removal. Cite this article: Bone Joint J 2018;100-B:909-14.

Background: The purpose of this study was to examine the outcomes of repeat revision after failure of a constrained liner., Methods: We reviewed 1212 consecutive revisions and identified 74 (6%) revisions of a failed constrained liner in 46 patients with a mean age of 65 years. The most common reasons for revision of a constrained liner were recurrent instability (64.9%) and infection (25.7%)., Results: At a mean of 35 months, 42 of the 74 hips (57%) required repeat revision. Kaplan-Meier revision-free survival was 24% at 10 years. Thirty-two of the 74 revisions (43%) had a dislocation event after the index revision. Kaplan-Meier dislocation-free survival was 43% at 10 years. There was a higher failure rate among the 34 patients with abductor deficiency (hazard ratio 1.90, 95% confidence interval, 1.06-3.43; P = .032)., Conclusion: Patients undergoing revision of a failed constrained liner have a high likelihood of recurrent dislocation and repeat revision surgery., Level of Evidence: Level IV., (Copyright © 2018. Published by Elsevier Inc.)

Background: Radiostereometric analysis (RSA) accurately assesses arthroplasty implant performance and is routinely used for research purposes. Because of its efficacy in detecting implant failure in research subjects, we deployed the use of RSA beads for routine surveillance in all elective total hip and total knee arthroplasty patients., Methods: We retrospectively compared 143 patients who received RSA beads intraoperatively with 343 patients who did not receive RSA beads. Using RSA images, we assessed bead stability at 6 weeks and 1 year postoperatively., Results: There were no intraoperative complications in the RSA group and two in the control group. No differences were found between groups for the surgical time and the expected blood loss. At 6 weeks, 99.5% of beads were considered to be stable, with stability increasing to 99.7% of beads at 1 year., Conclusion: The routine use of RSA bead insertion is a safe procedure and may provide the ability to assess implant fixation in clinical practice.

Background: The purpose of this study is to determine whether revision total hip arthroplasty (THA) is associated with increased rates of deep vein thrombosis (DVT) and pulmonary embolism (PE) when compared to primary THA., Methods: We queried the American College of Surgeons National Surgical Quality Improvement Program database for all primary and revision THA cases from 2011 to 2014. Demographic data, medical comorbidities, and venous thromboembolic rates within 30 days of surgery were compared between the primary and revision THA groups., Results: Revision THA had a higher rate of DVT than the primary THA (0.6% vs 0.4%, P = .016), but there was no difference in the rate of PE (0.3% vs 0.2%, P = .116). When controlling for confounding variables, revision surgery alone was not a risk factor for DVT (odds ratio 0.833, 95% confidence interval 0.564-1.232) or PE (odds ratio 1.009, 95% confidence interval 0.630-1.616). Independent risk factors for DVT include age >70 years, malnutrition, infection, operating time >3 hours, general anesthesia, American Society of Anesthesiologists classification 4 or greater, and kidney disease (all P < .05). Probability of DVT ranged from 0.2% with zero risk factors to 10% with all risk factors. Independent risk factors for PE included age >70 years, African American ethnicity, and operating time >3 hours (all P < .05) with probabilities of PE postoperatively ranging from 0.2% to 1.1% with all risk factors., Conclusion: Revision surgery alone is not a risk factor for venous thromboembolism after hip arthroplasty. Surgeons should weigh the risks and benefits of more aggressive anticoagulation in certain high-risk patients., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Accurate cup positioning is one of the most challenging aspects of total hip arthroplasty (THA). Undetected movement of the patient during THA surgery can lead to inaccuracies in cup anteversion and inclination, increasing the potential for dislocation and revision surgery. Investigations into the magnitude of patient motion during THA are not well represented in the literature., Methods: We analyzed intraoperative pelvic motion using a novel navigation device used to assist surgeons with cup position, leg length, and offset during THA. This device uses an integrated accelerometer to measure motion in 2 orthogonal degrees of freedom. We reviewed the data from 99 cases completed between February and September 2016., Results: The mean amount of pitch recorded per patient was 2.7° (standard deviation, 2.2; range, 0.1°-9.9°), whereas mean roll per patient was 7.3° (standard deviation, 5.5; range, 0.3°-31.3°). Twenty-one percent (21 of 99) of patients demonstrated pitch of >4°. Sixty-nine percent (68 of 99) of patients demonstrated >4° of roll, and 25% (25 of 99) of patients demonstrated roll of ≥10°., Conclusion: Our findings indicate that while the majority of intraoperative motion is <4°, many patients experience significant roll, with a large proportion rolling >10°. This degree of movement has implications for acetabular cup position, as failure to compensate for this motion can result in placement of the cup outside the planned safe zone, thus, increasing the potential for dislocation. Further study is warranted to determine the effect of this motion on cup position, leg length, and offset., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Incompletely solved problems in hip and knee arthroplasty present ongoing practice challenges., Methods: Content experts summarized treatment options and preferred treatment methods for 4 incompletely solved problems in hip and knee arthroplasty., Results: The problems chosen for discussion in this symposium included 2 soft tissue problems: chronic extensor mechanism deficiency after total knee arthroplasty and abductor deficiency after total hip arthroplasty (THA), recurrent infection after a 2-stage procedure for infected THA or total knee arthroplasties, and pelvic discontinuity after THA., Conclusion: The approaches outlined may provide guidance on management of these different problems. For surgeons and others in the orthopedic community interested in innovation, these challenges also present ripe opportunities to improve the care of patients with unmet needs., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: The purpose of this study was to evaluate the performance of dual-mobility articulations in patients at high risk for dislocation after revision total hip arthroplasty., Methods: We reviewed the results of 36 consecutive revision total hip arthroplasties performed on patients considered high risk for instability. Indications for inclusion included abductor insufficiency, recurrent instability, failure of constrained liner, or inadequate intraoperative stability when trialing., Results: At a minimum of 2 years, there were 4 (11.1%) repeat revisions including both dual-mobility liners that were cemented into an acetabular shell and 2 for deep infection treated with a 2-stage exchange. There was one dislocation that was successfully closed reduced but no revisions for recurrent instability. The mean Harris hip score improved from 45 to 90 points (P < .001)., Conclusion: Dual-mobility articulations are associated with a low rate of failure with no revisions for instability in this challenging group of patients., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Revision total hip arthroplasty in patients with a nonsupportive superior acetabulum often requires secondary augmentation beyond a hemispherical cup to achieve reliable fixation. Treatment options include using a higher hip center, jumbo cup, custom triflange implant, cages, or filling the superior defect with a bilobed implant, structural allograft, or metal augments. We previously reported a cohort of 31 patients treated with porous-coated hemispherical cups and distal femoral allograft for Paprosky type IIIA acetabular defects., Methods: The original cohort of 31 hips was retrospectively reviewed. Fourteen patients died with <15 years of follow-up, and 2 were lost to follow-up. This left 15 patients for evaluation including 5 males and 10 females, with an average age of 61 years (range: 37-74 years) at the time of surgery. Acetabular revision was performed with the use of a porous-coated hemispherical cup along with structural distal femoral allograft, cut to resemble the number 7, and secured with 6.5-mm cancellous screws with washers., Results: Overall, 7 hips failed, resulting in a Kaplan-Meier survivorship of 72% at 25 years of follow-up. In surviving patients, radiographs demonstrated components to be well fixed, and average Merle d'Aubigné score increased from 5 to 10 points. There were a subset of patients that failed early (median: 6.2 years), but the remaining patients demonstrated excellent clinical and radiographic results., Conclusions: The use of distal femoral allograft can be considered in young patients with type IIIA acetabular defects that could benefit from restoration of bone stock., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Femoral bone loss is a complex problem in revision total hip arthroplasty. The Paprosky classification is used when determining the degree and location of bone loss. Meticulous operative planning is essential where severe bone loss is a concern. One must correctly identify the bone loss pattern, safely remove the existing components, and proceed with the proper reconstruction technique based on the pattern of bone loss. This article discusses the etiology and classification of bone loss, clinical and radiographic evaluation, components of effective preoperative planning, and clinical results of various treatment options with a focus on more severe bone loss patterns., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Acetabular bone loss is a challenging problem facing the revision total hip replacement surgeon. Reconstruction of the acetabulum depends on the presence of anterosuperior and posteroinferior pelvic column support for component fixation and stability. The Paprosky classification is most commonly used when determining the location and degree of acetabular bone loss. Augments serve the function of either providing primary construct stability or supplementary fixation. When a pelvic discontinuity is encountered we advocate the use of an acetabular distraction technique with a jumbo cup and modular porous metal acetabular augments for the treatment of severe acetabular bone loss and associated chronic pelvic discontinuity., (©2014 The British Editorial Society of Bone & Joint Surgery.)

A pelvic discontinuity occurs when the superior and inferior parts of the hemi-pelvis are no longer connected, which is difficult to manage when associated with a failed total hip replacement. Chronic pelvic discontinuity is found in 0.9% to 2.1% of hip revision cases with risk factors including severe pelvic bone loss, female gender, prior pelvic radiation and rheumatoid arthritis. Common treatment options include: pelvic plating with allograft, cage reconstruction, custom triflange implants, and porous tantalum implants with modular augments. The optimal technique is dependent upon the degree of the discontinuity, the amount of available bone stock and the likelihood of achieving stable healing between the two segments. A method of treating pelvic discontinuity using porous tantalum components with a distraction technique that achieves both initial stability and subsequent long-term biological fixation is described., (©2014 The British Editorial Society of Bone & Joint Surgery.)

Acetabular osteolysis can be difficult to diagnose because patients often have no clinical symptoms even when there is substantial bone loss. Ideally, early detection would lead to early interventions. Imaging continues to be the frontline modality for the early detection of acetabular osteolysis. Although plain radiography is the current imaging modality most commonly used in routine follow-up examinations, its low sensitivity limits its usefulness. CT and MRI have proven to be better imaging modalities for the early detection of osteolysis; however, their use is limited by cost, radiation exposure, and time. Biomarkers hold promise for the early detection of osteolysis; however, their efficacy requires more rigorous research for validation. Early diagnosis and treatment of osteolysis may lead to better outcomes for patients.

Osteolysis in the periacetabular region is a common long-term complication of total hip arthroplasty that can lead to bone loss, implant loosening, and protrusio. Several systems have been developed for classifying osteolysis and guiding treatment. Options such as bone grafting or augmentation, with exchange of the bearing surface and, in some cases, revision of the acetabular component, can be used for treatment. Most cavitary and protrusio defects can be treated with a cementless revision cup using screw fixation and grafting with morcellized bone. However, structural augmentation, custom components, or cage reconstruction may occasionally be necessary for managing larger defects with severe loss of acetabular bone stock.

Powered trephines used over a femoral component to disrupt the bone component interface can yield acceptable clinical and radiographic outcomes while minimizing direct mechanical injury and indirect thermal necrosis. Thirty-six patients required trephining for fractured stems (16), infection (8), malposition (7), modular junction failure (4), and acetabular exposure (1). Harris Hip Scores (HHS), radiographic healing, and complications were assessed at a follow-up of 50.01 mo. Mean HHS increased from 46.61 preoperatively to 87.78 postoperatively (p<.0001). Two patients suffered spontaneous postoperative periprosthetic fractures in the region of the trephined bone at 3 mo and 4 mo postoperatively. Despite undergoing ORIF with locked plates, they both re-fractured with necrotic bone observed at the time of revision. There is a 5.6% incidence of femoral shaft fractures near the region of trephined bone within 1 year of surgery. Given the location of these fractures, thermal necrosis may have occurred and consideration should be given to distally bypassing the region of the femur that has been trephined., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Acetabular reconstruction in revision total hip arthroplasty can be complicated by acetabular bone loss. In patients with severe acetabular bone deficiency with segmental bone defects or pelvic discontinuity, obtaining a stable, well-fixed acetabular component can be challenging. Although porous-coated, uncemented hemispheric cups can be used in most acetabular revisions, as the severity of acetabular deficiency increases, more complex alternatives are needed. Antiprotrusio cages have traditionally been used in the presence of acetabular columnar deficits, but higher failure rates and complications necessitated the development of alternative treatments. More recently, porous-coated acetabular augments have become an attractive alternative to structural allograft and oblong components when segmental bone loss is present. In the setting of severe bone loss or pelvic discontinuity, multiple reconstructive options are available. Depending on individual patient characteristics, plating of the pelvic discontinuity along with structural allografts, custom components, and modular or standard reconstructive cages can be used to obtain a stable acetabular component.

As the incidence of primary and revision hip arthroplasty increases, the need for a comprehensive approach to acetabular revision cannot be overstated. In the presence of osteolysis, there is a substantial population of patients with a well-fixed acetabular shell. It will be helpful to orthopaedic surgeons to review the classification of acetabular defects, techniques for exposing an acetabular component when the femoral component will be retained, methods of facilitating access to osteolytic lesions, the principles of bone grafting, options for liner fixation, and when removal of a well-fixed shell is necessary.

If a surgeon is faced with altered lesser trochanter anatomy when revising the femoral component in revision total hip replacement, a peri-prosthetic fracture, or Paprosky type IIIb or type IV femoral bone loss, a modular tapered stem offers the advantages of accurately controlling femoral version and length. The splines of the taper allow rotational control, and improve the fit in femoral canals with diaphyseal bone loss. In general, two centimetres of diaphyseal contact is all that is needed to gain stability with modular tapered stems. By allowing the proximal body trial to rotate on a well-fixed distal segment during trial reduction, appropriate anteversion can be obtained in order to improve intra-operative stability, and decrease the dislocation risk. However, modular stems should not be used for all femoral revisions, as implant fracture and corrosion at modular junctions can still occur.

Primary total hip arthroplasty (THA) is one of the most effective procedures for managing end-stage hip arthritis. The burden of revision THA procedures is expected to increase along with the rise in number of primary THAs. The major indications for revision THA include instability, aseptic loosening, infection, osteolysis, wear-related complications, periprosthetic fracture, component malposition, and catastrophic implant fracture. Each of these conditions may be associated with mild or advanced bone loss. Careful patient evaluation and bone loss classification guide preoperative planning and overall patient care. Historically, uncemented fixation has provided the best results, but cemented fixation is required in some cases.

Serum metal ion levels increase after primary total hip arthroplasty (THA) regardless of bearing surface. We conducted a study to determine the effect of a second joint arthroplasty on existing serum metal ion levels at long-term followup. Twelve patients underwent primary THA and then either another THA (8 patients) or total knee arthroplasty (TKA) (4 patients). The secondary procedures were performed a mean of 102.7 months (range, 36-144 months) after the index surgeries. The secondary THA group had significantly elevated levels of cobalt ion at 36 and 48 months, chromium ion at 12 and 24 months, and titanium ion at 48 and 72 months. The TKA group had no significant differences in cobalt, chromium, or titanium ion levels up to 72 months after surgery. Overall, when metal-polyethylene THA was performed after primary THA, there was a trend toward elevated serum metal ion levels at all follow-up intervals. This trend should be investigated with larger clinical trials.

The prevalence of, risk factors, and management of proximal femoral remodeling in revision total hip arthroplasty is unknown. Therefore, we reviewed the files of 200 consecutive femoral revision arthroplasties to study this phenomenon. Remodeling was considered present if a properly sized diaphyseal-engaging acrylic template had appropriate distal canal fill but lied within 2mm of the proximal lateral endosteal cortex (definition 1) or completely outside the femoral canal (definition 2) on anteroposterior femoral radiographs. The prevalence of remodeling was 42% by definition 1 and 21% by definition 2. The strongest risk factors were loose femoral components and more severe femoral bone loss. Orthopedic surgeons performing revision arthroplasty should be prepared to encounter remodeling as its presence can complicate femoral component revision., (Copyright © 2013 Elsevier Inc. All rights reserved.)

We previously reported on the metal ion concentrations of cobalt, chromium, and titanium that were found in the serum of patients three years after they had undergone primary total hip arthroplasty as compared with the concentrations found in the serum of control patients who did not have an implant. This study is a concise update on the serum metal levels found in a cohort of these patients ten years after the time of hip implantation. Of the original seventy-five subjects, metal ion levels were available for forty patients (53%). Ten patients (hybrid group) had received a hybrid total hip replacement that consisted of a modular cobalt-alloy femoral stem with a cobalt-alloy femoral head that had been inserted with cement and a titanium acetabular socket that had been inserted without cement. Nine patients (cobalt-chromium [CoCr] group) had received an implant with an extensively porous-coated modular cobalt-alloy femoral stem and femoral head along with a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Eight patients (titanium group) had undergone insertion of a proximally porous-coated modular titanium-alloy femoral stem with a cobalt-alloy femoral head and a titanium acetabular socket; the femoral and acetabular components had each been inserted without cement. Thirteen patients (control group) from the original control group of patients who had not received an implant served as control subjects. Serum metal levels were measured with use of high-resolution sector field inductively coupled plasma mass spectrometry. The hybrid total hip arthroplasty group had mean cobalt levels that were 3.2 times higher at 120 months than they were at baseline, and the cobalt levels in that group were significantly higher than those in the titanium total hip arthroplasty group at thirty-six, sixty, eighty-four, ninety-six, and 120 months (p < 0.01). The hybrid group had mean chromium levels that were 3.9 times higher at 120 months than they were at baseline, and the CoCr total hip arthroplasty group had chromium levels that were 3.6 times higher at 120 months than they were at baseline. The serum titanium levels were higher in the titanium group at all follow-up time intervals as compared with the levels in all other groups, and the level in the titanium group at 120 months was eighteen times higher than it was at baseline (p < 0.01). Patients with well-functioning primary metal-on-polyethylene total hip replacements had elevated serum metal levels for as many as ten years postoperatively. Furthermore, metal release at the modular femoral head-neck junctions, rather than passive dissolution from porous ingrowth surfaces, was likely the dominant source of serum cobalt and chromium.

As the number of primary total hip arthroplasty (THA) procedures performed continues to rise, the burden of revision THA procedures is also expected to increase. Proper evaluation and management of acetabular bone loss at the time of revision surgery will be an increasing challenge facing orthopaedic surgeons. Proper preoperative patient assessment and detailed preoperative planning are essential in obtaining a good clinical result. Appropriate radiographs are critical in assessing acetabular bone loss, and specific classification schemes can identify bone loss patterns and guide available treatment options. Treatment options include impaction grafting and cementation of the acetabulum, noncemented hemispheric acetabular reconstruction, structural allograft reconstruction, noncemented reconstruction with modular porous metal augments, ring and cage reconstruction, oblong cup reconstruction, cup-cage reconstruction, and triflange reconstruction.

Background: Despite dislocation being the most frequent complication after revision THA, risk factors for its occurrence are not completely understood., Questions/purposes: We therefore (1) determined the overall risk of dislocation after revision THA in a large series of revision THAs using contemporary revision techniques, (2) identified patient-related risk factors predicting dislocation, and (3) identified surgical variables predicting dislocation., Methods: We performed 1211 revision THAs between June 2004 and October 2010 in 576 women and 415 men who had a mean age of 64.7 years (range, 25-95 years) at time of surgery. Forty-six (4%) were lost to followup and 13 died (1%), leaving 1152 hips followed for a minimum of 90 days (mean, 2 years; range, 90 days to 7.1 years). Multivariate logistic regression was performed to identify risk factors for dislocation. The model was also tested on patients followed for a minimum 1 year to assess any difference in longer followup., Results: One hundred thirteen patients dislocated over the followup period (9.8%). Factors that were different between patients who dislocated and those who remained stable included a history of at least one previous dislocation (odds ratio [OR] = 2.673), abductor deficiency (OR = 2.672), and Paprosky acetabulum class (OR = 1.522). Use of a constrained liner (OR = 0.503) and increased femoral head size (OR = 0.942) were protective against dislocation, while with longer followup a constrained liner was no longer significant., Conclusions: Dislocation remains a common problem after revision THA. Identifying these risk factors can assist in patient education and surgical planning. Recognition of these risk factors in both patient type and surgical strategy is important for the surgeon performing revision THA and for minimizing these risks., Level of Evidence: Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

A moderator and panel of five experts led an interactive session in discussing five challenging and interesting patient case presentations involving surgery of the hip. The hip pathologies reviewed included failed open reduction internal fixation of subcapital femoral neck fracture, bilateral hip disease, evaluation of pain after metal-on-metal hip arthroplasty, avascular necrosis, aseptic loosening secondary to osteolysis and polyethylene wear, and management of ceramic femoral head fracture.

Revision total hip arthroplasty (THA) is projected to increase by 137% from the years 2005 to 2030. Reconstruction of the femur with massive bone loss can be a formidable undertaking. The goals of revision surgery are to create a stable construct, preserve bone and soft tissues, augment deficient host bone, improve function, provide a foundation for future surgery, and create a biomechanically restored hip. Options for treatment of the compromised femur include: resection arthroplasty, allograft prosthetic composite (APC), proximal femoral replacement, cementless fixation with a modular tapered fluted stem, and impaction grafting. The purpose of this article is to review the treatment options along with their associated outcomes in the more severe femoral defects (Paprosky types IIIb and IV) in revision THA.

Background: Corrosion at the modular head-neck junction of the femoral component in total hip arthroplasty has been identified as a potential concern, although symptomatic adverse local tissue reactions secondary to corrosion have rarely been described., Methods: We retrospectively reviewed the records of ten patients with a metal-on-polyethylene total hip prosthesis, from three different manufacturers, who underwent revision surgery for corrosion at the modular head-neck junction., Results: All patients presented with pain or swelling around the hip, and two patients presented with recurrent instability. Serum cobalt levels were elevated prior to the revision arthroplasty and were typically more elevated than were serum chromium levels. Surgical findings included large soft-tissue masses and surrounding tissue damage with visible corrosion at the femoral head-neck junction; the two patients who presented with instability had severe damage to the hip abductor musculature. Pathology specimens consistently demonstrated areas of tissue necrosis. The patients were treated with debridement and a femoral head and liner exchange, with use of a ceramic femoral head with a titanium sleeve in eight cases. The mean Harris hip score improved from 58.1 points preoperatively to 89.7 points at a mean of 13.0 months after the revision surgery (p=0.01). Repeat serum cobalt levels, measured in six patients at a mean of 8.0 months following revision, decreased to a mean of 1.61 ng/mL, and chromium levels were similar to prerevision levels. One patient with moderate hip abductor muscle necrosis developed recurrent instability after revision and required a second revision arthroplasty., Conclusions: Adverse local tissue reactions can occur in patients with a metal-on-polyethylene bearing secondary to corrosion at the modular femoral head-neck taper, and their presentation is similar to the adverse local tissue reactions seen in patients with a metal-on-metal bearing. Elevated serum metal levels, particularly a differential elevation of serum cobalt levels with respect to chromium levels, can be helpful in establishing this diagnosis.

One potential strategy to decrease the risk of dislocation after revision total hip arthroplasty (THA) is the use of an abduction brace to limit flexion and adduction. The purpose of this study was to compare the dislocation rate after revision THA between patients treated with or without an abduction brace. Data were obtained from 1211 revision THAs performed in 610 women and 518 men who had a mean age of 64.7 years (range, 22-95 years) and were followed up for a minimum of 90 days. Five hundred two patients were braced, whereas 650 were not. The 90-day dislocation rate among patients who wore a brace was 5.2% compared with 5.7% in the nonbrace group (P = .70). Multivariate regression found no benefit to bracing (P = .37), while controlling for factors found to significantly affect dislocation rate in this population. Our data do not support the routine use of an abduction brace to aid in the prevention of dislocation., (Copyright © 2012 Elsevier Inc. All rights reserved.)

The purpose of this study was to evaluate patient perception of orthopedic surgeon reimbursement for total hip (THA) and knee (TKA) arthroplasty. A total of 1120 consecutive patients were asked what they believed a surgeon should be paid for performing THA and TKA. Patients were then asked to estimate what Medicare actually reimbursed for each of these procedures. On average, patients thought that surgeons should receive $14,358 for THA and $13,332 for TKA. Patients estimated actual Medicare reimbursement to be $8212 for THA and $7196 for TKA. Most of the patients stated that Medicare reimbursement was "much lower" than what it should be. Many patients commented that given this discrepancy, surgeons may drop Medicare, which may decrease access to quality hip and knee arthroplasties., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Seventy-five total hip arthroplasty revisions for instability were classified into 6 primary etiologies: I, acetabular component malposition; II, femoral component malposition; III, abductor deficiency; IV, impingement; V, late wear; or VI, unresolved etiology. The most common etiologies were cup malposition (type I; 33%) and abductor deficiency (type III; 36%). At a mean of 35.3 months, 11 redislocations occurred (14.6%). Acetabular revisions were protective against redislocation (P < .015). The number of previous operations (P = .0379) and previously failed constrained liners (P < .02) were risk factors for failure. Tripolar constrained liners demonstrated improved survivorship vs locking ring types (P < .02); cemented constrained liners failed more often than modular constrained liners (P < .0018). The highest risk of failure was in patients with abductor insufficiency with revisions for other etiologies having a success rate of 90%., (Published by Elsevier Inc.)

Background: Initial reports with short-term followup of porous tantalum acetabular components and augments for Paprosky IIIA acetabular defects demonstrate high hip scores, low rates of aseptic loosening, and low rates of complications. However, longer-term followup with a larger cohort is needed to determine the durability of these reconstructions., Questions/purposes: We therefore determined the functional scores, rates of aseptic loosening, and complications in patients with Paprosky IIIA acetabular defects treated with porous tantalum acetabular components and augments., Methods: We retrospectively reviewed 37 acetabular revisions in 36 patients (one patient with bilateral revisions) treated with a porous tantalum acetabular component and augment. All patients had defects classified as Type IIIa using the system of Paprosky et al. Harris hip scores were obtained and radiographic examination was performed before surgery and through most recent followup. The minimum followup was 26 months (mean, 60 months; range, 26-106 months)., Results: One patient developed aseptic loosening of the acetabular reconstruction requiring revision; seven other patients required further surgery for periprosthetic femoral fracture (two), acute infection (three), and recurrent dislocation (two). Thirty-five of 37 hips had no or occasional pain at final followup. Mean Harris hip scores improved from 33.0 preoperatively (range, 12.6-58.7) to 81.5 postoperatively (range, 27.0-99.8)., Conclusions: Although the complication rate requiring further surgery was considerable, most patients with these reconstructions had pain relief and reasonable function with low rates of loosening at midterm followup., Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

Eighty-seven hips with an infected total hip arthroplasty were treated with an antibiotic spacer and 6 weeks of antibiotics. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) measurements were repeated before attempted reimplanation, and a synovial fluid white blood cell (WBC) count was obtained intraoperatively. Nine hips (10.1%) had persistent infections. The mean ESR, CRP, and synovial fluid WBC count and differential decreased significantly (P < .001) between stages; however, the ESR remained elevated (>30 mm/h) in 50 patients (62.5%) and the CRP remained elevated (>10 mg/L) in 22 patients (27.5%) in whom the infection had been eradicated. The synovial fluid WBC count was the best test for identifying persistent infection, with an optimum cutoff of 3528 WBCs/microL(sensitivity, 78%; specificity, 96%) and an area under the curve of 0.91. The ESR and CRP were not sufficiently rigorous to aid in diagnosis and frequently failed to normalize even in patients without persistent infection., (Copyright 2010. Published by Elsevier Inc.)

The goal of this study is to evaluate the efficacy of using an extended trochanteric osteotomy (ETO) as part of a 2-stage exchange procedure for prosthetic hip infections. Twenty-three consecutive infected total hip arthroplasties in which an ETO was used as part of a 2-stage exchange procedure were retrospectively reviewed. An ETO was used when the femoral component could not be extracted using standard techniques. Clinical and radiographic parameters were evaluated at an average of 49 months of follow-up. Postoperatively, 20 of 23 (87%) patients had resolution of their infection, with healing of the ETO in 22 of 23 patients at a mean of 11.5 weeks. Preoperative modified D'Aubigne and Postel score means of 2.4 for pain and 2.6 for walking ability significantly improved (P < .001) to 5.3 and 4.9. Use of an ETO as part of a 2-stage exchange arthroplasty can be performed safely and effectively in appropriately selected cases.

A retrospective cohort study of 31 hips revised with a tripolar articular construct was performed. Patient demographics and preoperative and postoperative information were recorded. Indications for a tripolar construct were recurrent dislocation and the inability to attain intraoperative stability during hip revision. Nine patients (29%) were revised to the tripolar construct after failure of a constrained liner. Twenty patients (65%) had at least one episode of instability before the most recent revision. At a mean follow-up of 38 months, modified Postel scores improved from a mean of 5.28 to 9.64 (P < .01). Radiographic follow-up revealed no evidence of component loosening/migration, osteolysis, or polyethylene wear. Two patients (7%) required further revision surgery for recurrent instability. A tripolar construct was effective in eliminating or preventing instability in 93% of the complex cases treated. These early results support the use of a tripolar construct in treating recurrent instability or instability encountered at the time of revision hip arthroplasty.

Background: While multiple tests are used to determine the presence of infection at the site of a total hip arthroplasty, few studies have applied a consistent algorithm to determine the utility of the various tests that are available. The purpose of the present study was to evaluate the utility of commonly available tests for determining the presence of periprosthetic infection in patients undergoing revision total hip arthroplasty., Methods: Two hundred and thirty-five consecutive total hip arthroplasties in 220 patients were evaluated by one of two surgeons using a consistent algorithm to identify infection and were treated with reoperation. Receiver-operating-characteristic curve analysis was used to determine the optimal cut-point values for the white blood-cell count and the percentage of polymorphonuclear cells of intraoperatively aspirated hip synovial fluid. Sensitivity, specificity, negative predictive value, positive predictive value, and accuracy were determined. Patients were considered to have an infection if two of three criteria were met; the three criteria were a positive intraoperative culture, gross purulence at the time of reoperation, and positive histopathological findings., Results: Thirty-four arthroplasties were excluded because of the presence of a draining sinus, incomplete data, or a preoperative diagnosis of inflammatory arthritis, leaving 201 total hip arthroplasties available for evaluation. Fifty-five hips were judged to be infected. No hip in a patient with a preoperative erythrocyte sedimentation rate of <30 mm/hr and a C-reactive protein level of <10 mg/dL was determined to be infected. Receiver-operating-characteristic curve analysis of the synovial fluid illustrated optimal cut-points to be >4200 white blood cells/mL for the white blood-cell count and >80% polymorphonuclear cells for the differential count. However, when combined with an elevated erythrocyte sedimentation rate and C-reactive protein level, the optimal cut-point for the synovial fluid cell count was >3000 white blood cells/mL, which yielded the highest combined sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the tests studied., Discussion: A synovial fluid cell count of >3000 white blood cells/mL was the most predictive perioperative testing modality in our study for determining the presence of periprosthetic infection when combined with an elevated preoperative erythrocyte sedimentation rate and C-reactive protein level in patients undergoing revision total hip arthroplasty.

Managing severe acetabular bone loss in total hip arthroplasty revision can be a tremendous challenge. Osteolysis and migration of the acetabular component can lead to large uncontained defects. Traditionally, these deficiencies have been treated with allograft with or without the support of a cage. In severe cases, a majority of the cage support is via allograft instead of host bone. Sometimes, with remodeling and resorption of the allograft, the cage can lose structural support, leading to fatigue and failure. In these situations, trabecular metal has become a viable alternative. Deficiencies of acetabular bone can be independently addressed and reconstructed providing initial stability and, we believe, long-term biologic fixation to host bone.

Pelvic discontinuity can be encountered during acetabular revision in patients with severe bone loss. All patients who had an acetabular reconstruction for a type IIIB acetabular defect according to the classification of Paprosky et al [Paprosky WG, Perona PG, Lawrence JM. 1994. Acetabular defect classification and surgical reconstruction in revision arthroplasty. A 6-year follow-up evaluation. J Arthroplasty 9:33.] with an associated pelvic discontinuity between 2001 and 2003 were reviewed. A trabecular metal acetabular component with or that without an acetabular augment was used to obtain fixation proximal and distal to the discontinuity. Thirteen patients (13 hips) were treated for a type IIIB acetabular defect. At an average of 2.6 years of follow-up, 1 patient demonstrated possible radiographic loosening. The other 12 patients maintained radiographically stable hips. None of the patients required repeat surgical intervention. Clinically, the patients' modified Postel-Merle d'Aubigne score improved from 6.1 preoperatively to 10.3 postoperatively. The treatment of pelvic discontinuity during acetabular revision using a trabecular metal acetabular component with or that without an associated trabecular metal augment appears to provide reliable and reproducible short-term results.