Chronic Pelvic Discontinuity Research Articles

MANAGEMENT OF CHRONIC PELVIC DISCONTINUITY DURING REVISION HIP ARTHROPLASTY USING THE “ACETABULAR DISTRACTION TECHNIQUE”: CLINICAL AND RADIOLOGICAL OUTCOMES AT TWO TO TEN YEARS FROM A TWO-CENTRE STUDY

Chronic pelvic discontinuity (CPD) during revision hip arthroplasty is a challenging entity to address. The aim of this study was to evaluate the clinical and radiologic outcomes, and complications of the “acetabular distraction technique” for the management of CPD during revision hip arthroplasty.Patients with CPD, who underwent acetabular revision between 2014 and 2022 at two tertiary care centres, using an identical distraction technique, were evaluated. Demographic parameters, pre-operative acetabular bone loss, duration of follow-up, clinical and radiologic outcomes, and survivorship were evaluated.In all, 46 patients with a mean follow-up of 34.4 (SD=19.6, range: 24–120) months were available for evaluation. There were 25 (54.3%) male, and 21 (45.7%) female patients, with a mean age of 58.1 (SD=10.5, range: 40–81) years at the time of revision surgery. Based on the Paprosky classification of acetabular bone loss, 19 (41.3%), 12 (26.1%), and 15 (32.6%) patients had type 3b, 3a, and 2c defects. All patients were managed using the Trabecular Metal™ Acetabular Revision System; 16 patients required additional Trabecular Metal™ augments. The mean HHS improved from 50.1 (SD=7.6, range: 34.3 – 59.8) pre-operatively, to 86.6 (SD=4.2, range: 74.8 -91.8) at the last follow-up. Two patients (4.3 %) developed partial sciatic nerve palsy, two (4.3%) had posterior dislocation, and one (2.2%) required re-revision for aseptic loosening. Radiologically, 36 (78.3%) patients showed healing of the pelvic discontinuity. The Kaplan-Meier construct survivorship was 97.78% when using re-revision for aseptic acetabular loosening as an endpoint.The acetabular distraction technique has good clinical and radiologic outcomes in the management of CPD during revision hip arthroplasty.

Acetabular Distraction: Promising 5-Year Outcomes for the Treatment of Chronic Pelvic Discontinuity

BackgroundSevere 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. MethodsWe 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. ResultsA 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. ConclusionsFor 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 EvidenceLevel III, retrospective comparative study.

How modular porous metal augments have changed the management of acetabular bone loss at primary or revision total hip arthroplasty.

The advent of modular porous metal augments has ushered in a new form of treatment for acetabular bone loss. The function of an augment can be seen as reducing the size of a defect or reconstituting the anterosuperior/posteroinferior columns and/or allowing supplementary fixation. Depending on the function of the augment, the surgeon can decide on the sequence of introduction of the hemispherical shell, before or after the augment. Augments should always, however, be used with cement to form a unit with the acetabular component. Given their versatility, augments also allow the use of a hemispherical shell in a position that restores the centre of rotation and biomechanics of the hip. Progressive shedding or the appearance of metal debris is a particular finding with augments and, with other radiological signs of failure, should be recognized on serial radiographs. Mid- to long-term outcomes in studies reporting the use of augments with hemispherical shells in revision total hip arthroplasty have shown rates of survival of > 90%. However, a higher risk of failure has been reported when augments have been used for patients with chronic pelvic discontinuity.

Evaluation and Management of Acetabular Bone Loss in Revision Total Hip Arthroplasty: A 10-year Update.

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.

Acetabular Distraction Technique: A Multicenter Study With a Minimum 2-Year Radiographic Follow-Up

BackgroundChronic 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. MethodsPatients 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. ResultsAmong 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. ConclusionsTo 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 EvidenceLevel III, Retrospective Comparative Study.

Superior Pubic Ramus Screw Placement During Complex Acetabular Revision: Acetabular Distraction for Treatment of Pelvic Discontinuity.

With the patient in the lateral decubitus position, the acetabulum is exposed from a standard posterior approach for a revision THA. The location of the superior pubic root is identified after making a recess within the anteroinferior capsule. In order to ensure that the appropriate trajectory is obtained, C-arm imaging (inlet view and orthogonal obturator outlet views) is utilized to safely predrill the screw trajectory into the superior pubic ramus. A Kirschner wire (K-wire) is then placed into the hole. With use of a metal-cutting burr on the back table, customized peripheral screw holes are placed and then the acetabular component is slid and impacted into place over the K-wire. After cup insertion, the K-wire is removed and the superior pubic ramus screw can be placed and confirmed on fluoroscopy. In general, chronic pelvic discontinuity requires surgical management with revision THA and has historically employed the use of a cup-cage construct, custom triflange implants, and/or jumbo acetabular cups with modular porous metal augments1-5. With these treatment options, it is typically necessary to insert "kickstand" screws, which function to prevent abduction failure of the acetabular cup4,5. However, in many cases of discontinuity, there may be severe ischial osteolysis, making ischial screw placement difficult or impossible. The superior pubic ramus, however, remains a reliable option that can be utilized for inferior screw fixation, even in cases of severe acetabular bone loss, and thus is especially beneficial in these difficult cases. The technique of acetabular distraction was developed because of limitations with alternative techniques. This procedure achieves cementless biologic fixation and eventual discontinuity healing as a result of lateral or peripheral acetabular distraction and resultant medial or central compression across the pelvic discontinuity. Acetabular distraction allows for intraoperative customization and cement unitization of the acetabular construct. This procedure requires the use of a "kickstand" screw or of inferior screw fixation in order to prevent abduction failure of the cup. These screws may be placed into either the ischium or superior pubic ramus. If the patient has substantial ischial osteolysis, ischial screw fixation may not be possible. If not placed in a systematic manner, pubic ramus screws can be technically challenging, and incorrect placement can result in neurovascular injury. The present video article demonstrates a reproducible technical method for safely placing a screw in the superior ramus to aid in optimal fixation of the acetabular component in cases of pelvic discontinuity. Thus far, short-term survivorship of acetabular distraction with use of a jumbo cup and kickstand screws has been about 95%. In the largest study to date assessing patients with chronic pelvic discontinuity who underwent revision THA with use of the acetabular distraction technique, only 1 of 32 patients required revision for aseptic loosening6. An additional 2 patients had evidence of radiographic loosening but did not undergo revision, and 3 had migration of the acetabular component into a more stable configuration. Radiographically, 22 of 32 patients in the study demonstrated healing of the discontinuity6. In another study assessing the survivorship of porous tantalum acetabular shells in revision THA to treat severe acetabular defects, patients with inferior screw fixation with superior pubic ramus or ischial screws had a significantly lower incidence of proximal translation of components compared with those without inferior screw fixation7. For reproducible, successful execution of this technique, it is important to confirm correct placement of the acetabular retractors at the correct anatomical locations to ensure adequate surgical visualization of the acetabulum for easy identification of the superior pubic root.It is also critical to check placement of the drill via fluoroscopy with an inlet and obturator outlet views prior to drilling.The drill should be advanced on the oscillate setting to avoid inadvertently perforating the cortical bone and damaging surrounding neurovascular structures. OR = operating roomf/u = follow-upvac = vacuum-assisted closureRSA = radiostereometric analysis.

Pelvic discontinuity: a challenge to overcome.

Pelvic discontinuity (PD) has been a considerable challenge for the hip revision arthroplasty surgeon. However, not all PDs are the same. Some occur during primary cup insertion, resembling a fresh periprosthetic fracture that separates the superior and inferior portions of the pelvis, while others are chronic as a result of gradual acetabular bone loss due to osteolysis and/or acetabular implant loosening.In the past, ORIF, various types of cages, bone grafts and bone cement were utilized with little success. Today, the biomechanics and biology of PD as well as new diagnostic tools and especially a variety of new implants and techniques are available to hip revision surgeons. Ultraporous cups and augments, cup-cage constructs and custom triflange components have revolutionized the treatment of PD when used in various combinations with ORIF and bone grafts. For chronic PD the cup-cage construct is the most popular method of reconstruction with good medium-term results.Dislocation continues to be the leading cause of failure in all situations, followed by infection. Ultimately, surgeons today have a big enough armamentarium to select the best treatment approach. Case individualization, personal experience and improvisation are the best assets to drive treatment decisions and strategies.Cite this article: EFORT Open Rev 2021;6:459-471. DOI: 10.1302/2058-5241.6.210022

Reverse reaming distraction for acetabular reconstruction of chronic pelvic discontinuity

BackgroundThe acetabular distraction technique demonstrates encouraging radiographic and clinical outcomes in treating chronic pelvic discontinuity. The aim of this study is to describe a modified distraction technique and to show our results.MethodsThis study identified 12 cases of chronic pelvic discontinuity undergoing primary or revision total hip arthroplasty (THA) with the technique of reverse reaming distraction between July 2015 and November 2018. All 12 patients had a minimum follow-up of 12 months. Radiographs were reviewed to inspect for component loosening. Clinical assessment included the Harris hip score (HHS) and an ambulatory scoring system.ResultsAt the time of final follow-up, no patient was revised. One patient had up to 1 cm migration of the cup in a horizontal or vertical direction and more than 20° change in the abduction angle but was asymptomatic. In the remaining 11 patients, no migration of the component was detected. Both the HHS and ambulatory score showed improvement in all patients. There were no perioperative complications. No postoperative dislocation occurred.ConclusionsReverse reaming distraction is a feasible technique in treatment of chronic pelvic discontinuity, with encouraging results at early term. However, ongoing follow-up is required to determine the long-term prognosis in patients receiving this technique.

Outcomes of Acetabular Reconstructions for the Management of Chronic Pelvic Discontinuity: A Systematic Review

BackgroundA number of articles have been published reporting on the clinical outcomes of various acetabular reconstructions for the management of chronic pelvic discontinuity (PD). However, no systematic review of the literature has been published to date comparing the outcome and complications of different approaches to reconstruction. MethodsThe US National Library of Medicine (PubMed/MEDLINE) and EMBASE were queried for publications from January 1980 to January 2019 using keywords pertinent to total hip arthroplasty, PD, acetabular dissociation, clinical or functional outcomes, and revision total hip arthroplasty or postoperative complications. ResultsOverall, 18 articles were included in this analysis (569 cases with chronic PD). The overall survival rate of the acetabular components used for the treatment of chronic PD was 84.7% (482 of 569 cases) at mid-term follow-up, whereas the most common reasons for revision were aseptic loosening (54 of 569 hips; 9.5%), dislocations (45 of 569 hips; 7.9%), periprosthetic joint infection (30 of 569 hips; 5.3%), and periprosthetic fractures (11 of 569 hips; 1.9%). Both pelvic distraction technique (combined with highly porous shells) and custom triflanges resulted in less than 5% failure rates (96.2% and 95.8%, respectively) at final follow-up. Also, highly effective in the treatment of PD were cup-cages and highly porous shells with and/or without augments with 92% survivorship free of revision for aseptic loosening for both reconstruction methods. Inferior outcomes were reported for conventional cementless shells combined with acetabular plates (72.7%) as well as ilioischial cages and reconstruction rings (66.7% and 60.6% survivorship, respectively). ConclusionThe current literature contains moderate quality evidence in support of the use of custom triflange implants and pelvic distraction techniques for the treatment of chronic PD, with a less than 5% all-cause revision rate and low complication rates at mean mid-term follow-up. Cup-cages and highly porous shells with or without augments could also be considered for the treatment of PD because both resulted in greater than 90% survival rates. Finally, there is still no consensus regarding the impact of different types of acetabular reconstruction methods on optimizing the healing potential of PD, and further studies are required in this area to better understand the influence of PD healing on construct survivorship and functional outcomes with each reconstruction method.

Mid-Term Outcomes of Revision Hip Arthroplasty with Acetabular Augments

Acetabular defects are a major obstacle to achieving good outcomes after revision hip arthroplasty. One way to deal with this problem is to use acetabular augments. We aimed to describe mid-term outcomes of revision hip arthroplasty using acetabular augments.Materials and methods. We analyzed 85 cases (83 patients) of revision hip arthroplasty using acetabular augments performed during 2012-2018 period: 53 women and 30 men with average age of 57±13 years (25-79). Distribution of acetabular defects was: 51 cases — Paprosky IIIA, 17 cases — Paprosky IIIB, 12 cases — Paprosky IIB, 5 cases — Paprosky IIC. 14 patients had chronic pelvic discontinuity. Aseptic loosening was indication for the operation in 83 cases, periprosthetic hip fracture — 1, dislocation — 1. The amount of previously undregone ipsilateral hipsurgeries was 1 in 35 cases, 2 in 25 cases, 3 and more in 25 cases. Average follow-up period was 38±19 months (1-79).Results. The average HHS score improved from 37±7 preoperatively to 73±9 after 3 months and to 80±11 after 12 months postoperatively (p = 0.001). Average VAS score improved from 7±2 preoperatively to 4±1 after 3 months and to 3±1 after 12 months postoperatively (p = 0.001). Stable acetabular fixation was achieved in each case according to X-ray findings at final follow-up. However, radiolucent lines were present around the cup in 10 cases (11.8 %) followed by no clinical evidence of aseptic loosening. Hip center of rotation was restored from 26.40±18.38 mm (4-75) preoperatively to 4.78±5.02 mm (0-20) postoperatively relatively to 0 point. Complications manifested in 9 out of 85 cases (10,6%). Distribution of complications was: periprosthetic joint infection in 6 cases, recurrent dislocation — 2, periprosthetic hip fracture — 1.7 patients required implant removal and exchange.Conclusions. Good mid-term outcomes can be achieved using acetabular augments during hip revision surgery in setting of acetabular defects. Acetabular augments are a reliable option in case of Paprosky IIIB, IIIA defects and chronic pelvic discontinuity, providing good mechanical stability.

Mid-Term Outcomes of Revision Hip Arthroplasty with Acetabular Augments

Acetabular defects are a major obstacle to achieving good outcomes after revision hip arthroplasty. One way to deal with this problem is to use acetabular augments. We aimed to describe mid-term outcomes of revision hip arthroplasty using acetabular augments.Materials and methods. We analyzed 85 cases (83 patients) of revision hip arthroplasty using acetabular augments performed during 2012-2018 period: 53 women and 30 men with average age of 57±13 years (25-79). Distribution of acetabular defects was: 51 cases — Paprosky IIIA, 17 cases — Paprosky IIIB, 12 cases — Paprosky IIB, 5 cases — Paprosky IIC. 14 patients had chronic pelvic discontinuity. Aseptic loosening was indication for the operation in 83 cases, periprosthetic hip fracture — 1, dislocation — 1. The amount of previously undregone ipsilateral hipsurgeries was 1 in 35 cases, 2 in 25 cases, 3 and more in 25 cases. Average follow-up period was 38±19 months (1-79).Results. The average HHS score improved from 37±7 preoperatively to 73±9 after 3 months and to 80±11 after 12 months postoperatively (p = 0.001). Average VAS score improved from 7±2 preoperatively to 4±1 after 3 months and to 3±1 after 12 months postoperatively (p = 0.001). Stable acetabular fixation was achieved in each case according to X-ray findings at final follow-up. However, radiolucent lines were present around the cup in 10 cases (11.8 %) followed by no clinical evidence of aseptic loosening. Hip center of rotation was restored from 26.40±18.38 mm (4-75) preoperatively to 4.78±5.02 mm (0-20) postoperatively relatively to 0 point. Complications manifested in 9 out of 85 cases (10,6%). Distribution of complications was: periprosthetic joint infection in 6 cases, recurrent dislocation — 2, periprosthetic hip fracture — 1.7 patients required implant removal and exchange.Conclusions. Good mid-term outcomes can be achieved using acetabular augments during hip revision surgery in setting of acetabular defects. Acetabular augments are a reliable option in case of Paprosky IIIB, IIIA defects and chronic pelvic discontinuity, providing good mechanical stability.

Two-centre radiological survivorship of acetabular distraction technique for treatment of chronic pelvic discontinuity: mean five-year follow-up.

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.

The treatment of acetabular bone loss with associated pelvic discontinuity in revision of total hip arthroplasty: Acetabular distraction technique

Abstract Introduction: 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. With patients undergoing THA at younger ages and living longer, revision patients are presenting with greater bone loss at the time of revision surgery. The proper evaluation and treatment of acetabular bone loss at the time of revision surgery is complex and is further complicated in the face of a chronic pelvic discontinuity. Identifying proper pre-operative patient assessment in conjunction with detailed pre-operative planning is essential for obtaining favorable clinical results. Appropriate radiographs are critical in assessing acetabular bone loss, and specific classification schemes can identify bone loss patterns and guide available treatment options. The presentation reviews the surgical decision making and clinical results of different surgical options for the treatment of acetabular bone loss, and introduces a novel technique for the treatment of a chronic pelvic discontinuity. Background: Pelvic intermittence happens frequently in patients of female sex, with a background marked by earlier pelvic radiation or rheumatoid arthritis.The two most normal order frameworks are the AAOS Classification System and the Paprosky Classification, with the Paprosky Classification giving treatment proposals dependent on the degree and area of bone misfortune, accordingly considering pre-usable planning. also, follow-up examines have shown sufficient legitimacy and dependability of this grouping framework. There are three significant elements concerning accomplishing an effective result while rewarding pelvic intermittence: the measure of bone stock staying, biologic in-development potential, and the recuperating capability of the discontinuity. Treatment choices incorporate pen recreation with mass acetabular allograft, custom triflange acetabular segment (CTAC), a cup-confine build, enormous acetabular cup with permeable metal expands, or acetabular interruption with a permeable tantalum shell with or without secluded permeable increases. This audit article talks about grouping, assessment, recreation choices and results of incessant pelvic brokenness. Method:- Positive clinical results depend on cautious assessment and pre-usable arranging. Patients frequently present clinically with torment, trouble with ambulation and leg-length error because of relocation of the cup and hip focus. A point by point history ought to be recorded seeing the list technique just as pre-and post-employable indications. A full arrangement of radiographs ought to be gotten including an anteroposterior (AP) pelvis, AP and horizontal of the hip, and a cross-table parallel of the hip. Now and again, a processed tomography (CT) can be an amazing aide to survey the degree and area of bone misfortune, as it is much of the time thought little of on plain radiographs.13 In cases with serious average relocation, CT angiography ought to be acquired to comprehend the relationship of intra-pelvic neurovascular structures to the acetabular segment. Pre-usable research center assessment including white platelet tally, erythrocyte sedimentation rate, and C-receptive protein ought to be gotten before all correction THAs. Raised markers should provoke a pre-usable hip yearning. Results: Acetabular bone misfortune and constant pelvic brokenness in correction THA is a difficult and progressively visit issue. Suitable pre-employable workup and adjustment procedures are expected to get long haul cementless obsession and develop security. The Paprosky characterization framework ought to be utilized all together the assistance direct the fitting treatment intercession. Numerous treatment choices are accessible and show acceptable results. Our treatment of decision for ceaseless pelvic intermittence is acetabular interruption strategy with or without the utilization of permeable metal secluded enlarges. Information in regards to treatment results of interruption are restricted, however early results are promising, and this is the creator's favored treatment for interminable pelvic intermittence. Biography: Neil Sheth is an Assistant Professor of Orthopaedic Surgery at University of Pennsylvania. He is also the Pennsylvania Hospital Site Director for the adult reconstruction hip and knee fellowship. He obtained his Under-graduate degree in Biomedical Engineering with a minor in Finance at University of Pennsylvania. He then spent two years on Wall Street as a Financial Analyst at Solomon Smith Barney's Healthcare Investment banking division prior to attending medical school at Albany Medical College. Following medical school, he completed six year Orthopaedic Surgery Residency at Hospital of the University of Pennsylvania. Following residency, he completed an adult hip and knee reconstruction fellowship at Rush University as well as a three-month mini-fellowship at the Endo Klinik in Hamburg, Germany focusing on peri-prosthetic infection. He is currently leading a team to build an orthopedic center of excellence in Moshi, Tanzania.

The role of cages in the management of severe acetabular bone defects at revision arthroplasty.

An uncemented hemispherical acetabular component is the mainstay of acetabular revision and gives excellent long-term results. Occasionally, the degree of acetabular bone loss means that a hemispherical component will be unstable when sited in the correct anatomical location or there is minimal bleeding host bone left for biological fixation. On these occasions an alternative method of reconstruction has to be used. A major column structural allograft has been shown to restore the deficient bone stock to some degree, but it needs to be off-loaded with a reconstruction cage to prevent collapse of the graft. The use of porous metal augments is a promising method of overcoming some of the problems associated with structural allograft. If the defect is large, the augment needs to be protected by a cage to allow ingrowth to occur. Cup-cage reconstruction is an effective method of treating chronic pelvic discontinuity and large contained or uncontained bone defects. This paper presents the indications, surgical techniques and outcomes of various methods which use acetabular reconstruction cages for revision total hip arthroplasty.

Acetabular distraction technique—An alternative for the treatment of chronic pelvic discontinuity

Severe acetabular bone loss in the setting of revision total hip arthroplasty is a complex problem. Certain acetabular bone loss patterns can be associated with chronic pelvic discontinuity. There are several options available for the treatment of acetabular bone loss with associated chronic pelvic discontinuity. The literature demonstrates variable results with each technique. We present a novel surgical technique called acetabular distraction with the use of a porous metal shell and modular porous metal augments. This technique allows for peripheral or lateral acetabular distraction and medial or central compression at the site of the discontinuity.

Promising Mid-term Results With a Cup-cage Construct for Large Acetabular Defects and Pelvic Discontinuity.

Restoring normal anatomy and achieving stable fixation of the acetabular component can be especially challenging when the surgeon must deal with severe acetabular defects and/or pelvic discontinuity. The cup-cage (CC) construct, where an ilioischial cage is cemented within a biologically fixed porous metal cup, has emerged as an excellent option to treat such challenges. We sought to determine (1) mid-term Kaplan-Meier survival; (2) clinical outcomes based on Merle d'Aubigné-Postel scores; (3) radiological outcomes based primarily on construct migration; and (4) the complication rate for a series of 67 CC procedures performed at our institution. All hip revision procedures between January 2003 and March 2012 where a CC was used (with the exception of tumor cases or acute fracture; four total cases) that had a minimum 2-year followup and that had been seen within the last 2 years were included in this retrospective review. Acetabular bone loss and presence of pelvic discontinuity were assessed according to the Gross classification. Sixty-seven CC procedures with an average followup of 74 months (range, 24-135 months; SD, 34.3) months were identified; 26 of 67 (39%) were Gross Type IV and 41 of 67 (61%) were Gross Type V (pelvic discontinuity). Postoperative clinical and radiological evaluation was done annually. Merle d'Aubigné-Postel scores were recorded and all radiographs were compared with the 6-week postoperative radiographs to evaluate for radiographic loosening or migration. Failure was defined as revision surgery for any cause, including infection. The 5-year Kaplan-Meier survival rate with revision for any cause representing failure was 93% (95% confidence interval [CI], 83.1-97.4), and the 10-year survival rate was 85% (95% CI, 67.2-93.8). The Merle d'Aubigné-Postel score improved significantly from a mean of 6 preoperatively to 13 postoperatively (p < 0.001). Four CC had nonprogressive radiological migration of the ischial flange and they remain stable. We believe that the CC construct is a suitable choice to treat chronic pelvic discontinuity; it also remains a reliable option for the treatment of severe acetabular bone defects if stable fixation cannot be obtained through the use of a trabecular metal cup with or without augments. Level IV, therapeutic study.

Acetabular distraction: an alternative approach to pelvic discontinuity in failed total hip replacement.

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.

Acetabular distraction: an alternative for severe acetabular bone loss and chronic pelvic discontinuity.

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.

Acetabular Distraction: An Alternative for Severe Defects with Chronic Pelvic Discontinuity?

Stabilization of a pelvic discontinuity with a posterior column plate with or without an associated acetabular cage sometimes results in persistent micromotion across the discontinuity with late fatigue failure and component loosening. Acetabular distraction offers an alternative technique for reconstruction in cases of severe bone loss with an associated pelvic discontinuity. We describe the acetabular distraction technique with porous tantalum components and evaluate its survival, function, and complication rate in patients undergoing revision for chronic pelvic discontinuity. Between 2002 and 2006, we treated 28 patients with a chronic pelvic discontinuity with acetabular reconstruction using acetabular distraction. A porous tantalum elliptical acetabular component was used alone or with an associated modular porous tantalum augment in all patients. Three patients died and five were lost to followup before 2 years. The remaining 20 patients were followed semiannually for a minimum of 2 years (average, 4.5 years; range, 2-7 years) with clinical (Merle d'Aubigné-Postel score) and radiographic (loosening, migration, failure) evaluation. One of the 20 patients required rerevision for aseptic loosening. Fifteen patients remained radiographically stable at last followup. Four patients had early migration of their acetabular component but thereafter remained clinically asymptomatic and radiographically stable. At latest followup, the average improvement in the patients not requiring rerevision using the modified Merle d'Aubigné-Postel score was 6.6 (range, 3.3-9.6). There were no postoperative dislocations; however, one patient had an infection, one a vascular injury, and one a bowel injury. Acetabular distraction with porous tantalum components provides predictable pain relief and durability at 2- to 7-year followup when reconstructing severe acetabular defects with an associated pelvic discontinuity. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

The Reconstruction of Periprosthetic Pelvic Discontinuity

The surgical techniques and outcomes of acetabular reconstruction for periprosthetic pelvic discontinuity cases are reported. The mean time to surgery for 9 patients with acute pelvic discontinuity was 16.3 days, with 8 patients (88%) having posterior column plating and a porous metal acetabular cup. No cases required revision surgery, with a mean follow-up of 34 months (range, 24-67 months). Of the 62 chronic pelvic discontinuity cases, 20 had an ilioischial cage, with a revision rate of 29%. There were 42 cup-cage reconstructions with an 8-year survivorship of 86.3%, with a mean follow-up of 35 months (range, 24-93 months). Stable reconstruction of chronic pelvic discontinuity was achievable by distraction using a cup-cage acetabular reconstruction; however, satisfactory stability of acute pelvic discontinuity was achieved with compression of the posterior column using screw augmentation of the acetabular shell supplemented by posterior column plating.