Search

Background: Preoperative planning in total hip arthroplasty (THA) involves utilizing radiographs or advanced imaging modalities, including computerized tomography scans, for precise prediction of implant sizing and positioning. This study aimed to compare 3-dimensional (3D) versus 2-dimensional (2D) preoperative planning in primary THA with respect to key surgical metrics, including restoration of the horizontal and vertical center of rotation (COR), combined offset, and leg length., Methods: This study included 60 patients undergoing primary THA for symptomatic hip osteoarthritis (OA), randomly allocated to either robotic arm-assisted or conventional THA. Digital 2D templating and 3D planning using the robotic software were performed for all patients. All measurements to evaluate the accuracy of templating methods were conducted on the preoperative computerized tomography scanogram, using the contralateral hip as a reference. Sensitivity analyses explored differences between 2D and 3D planning in patients who had superolateral or medial OA patterns., Results: Compared to 2D templating, 3D templating was associated with less medialization of the horizontal COR (-1.2 versus -0.2 mm, P = .002) and more accurate restoration of the vertical COR (1.63 versus 0.3 mm, P < .001) with respect to the contralateral side. Furthermore, 3D templating was superior for planned restoration of leg length (+0.23 versus -0.74 mm, P = .019). Sensitivity analyses demonstrated that in patients who had medial OA, 3D planning resulted in less medialization of horizontal COR and less offset reduction. Conversely, in patients who had superolateral OA, there was less lateralization of horizontal COR and less offset increase using 3D planning. Additionally, 3D planning showed superior reproducibility for stem, acetabular cup sizes, and neck angle, while 2D planning often led to smaller stem and cup sizes., Conclusions: Our findings indicated higher accuracy in the planned restoration of native joint mechanics using 3D planning. Additionally, this study highlights distinct variances between the 2 planning methods across different OA pattern subtypes, offering valuable insights for clinicians employing 2D planning., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: Cementless stem designs with proximal metaphyseal fixation aim to achieve better load distribution, reduce stress shielding, and improve primary stability. The purpose of this prospective, randomized controlled trial was to evaluate the 2-year migration and clinical outcomes of two cementless femoral stems., Methods: A total of 60 participants undergoing primary total hip arthroplasty for any cause were randomly allocated to receiving either a proximally coated, short blade stem or a quadrangular-taper stem with a reinforced proximal body. Radiostereometric analysis radiographs were performed postoperatively and at 6 weeks, 6 months, 1 year and 2 years. The Harris Hip Score, Oxford Hip Score and the EuroQol five-dimension were also collected., Results: At two years, the median subsidence of the short-blade stem was 0.097 millimeters (mm) [Interquartile range (IQR) -0.67 to 0.08)] versus 0.086 mm(IQR, -0.29 to 0.005, P = .683); medial translation 0.023 mm (IQR 0.08 to 0.12) versus 0.029 mm(IQR -0.07 to 0.10, P = .907); anterior translation 0.035 mm (IQR -0.23 to 0.33) versus 0.07 mm (IQR -0.13 to 0.08, P = .268). At 24 months postoperatively, there were no stem revisions and Patient-Reported Outcome Measures (PROMs) were comparable between groups., Conclusion: Both cementless stems exhibited a predictable migration pattern and achieved initial stability. There was no difference in migration across the three Cartesian axes at any time point. Clinical outcomes and PROMs were also comparable. Biological fixation of both implants evidenced by the radiostereometric analysis and excellent PROMs are likely to translate to longer-term stability, which would need to be corroborated by longer-term outcome studies., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Robotic-arm assisted total hip arthroplasty (RO THA) has been shown to improve the accuracy of component positioning compared with conventional total hip arthroplasty (CO THA). This study reports Patient-Reported Outcome Measures (PROMs) of a previous trial that showed that RO THA was associated with improved accuracy and reduced outliers in acetabular component positioning compared with CO THA., Methods: This prospective cohort study included 50 patients undergoing CO THA versus 50 patients receiving RO THA. The Oxford hip score, Forgotten Joint Score (FJS), University of California at Los Angeles hip score were recorded at a minimum of 3 years following surgery., Results: At minimum 3 years follow-up, there was no statistically significant difference in CO THA versus RO THA with respect to the Oxford hip score [median 42(6.25) versus 41(5.5), P = .914]; FJS [89 (9.25) versus 86 (9), P = .065], and University of California at Los Angeles score [median 7.5 (3) versus 7 (2), P = .381]. None of the study patients had dislocations or underwent revision surgery within 3 years follow-up., Conclusion: The previously reported improvement in accuracy of acetabular component in this study population did not translate to statistically significant improvements in PROMs. Patients in both groups achieved excellent PROMs and there was a trend towards higher FJS scores postoperatively in the RO THA group that did not reach statistical significance. Further studies are needed to assess the significance of these findings on longer-term clinical outcomes and implant survivorships, and also to explore the impact of the enhanced RO THA workflow and functional implant positioning on these outcomes., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: In an effort to increase satisfaction among total knee arthroplasty (TKA) patients, emphasis has been placed on implant positioning and limb alignment. Traditionally, the aim for TKA has been to achieve a neutral mechanical alignment (MA) to maximize implant longevity. However, with the recent spike in interest in individualized alignment techniques and with the advent of new technologies, surgeons are slowly evolving away from classical MA., Methods: This review elucidates the differences in alignment techniques for TKA, describes the concept of knee phenotypes, summarizes comparative studies between MA and individualized alignment, and provides a simple way to incorporate the latter into surgeons' practice., Results: In order to manage patients by applying these strategies in day-to-day practice, a basic understanding of the aforementioned concepts is essential. Transition to an individualized alignment technique should be done gradually with caution in a stepwise approach., Conclusion: Alignment and implant positioning are now at the heart of the debate and surgeons are investigating a more personalized approach to TKA., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Implant malalignment may be a risk factor for poor patient-reported outcomes measures (PROMs) following total knee arthroplasty (TKA)., Methods: Postoperative surveys were administered to assess PROMs regarding satisfaction, pain, and function in 262 patients who underwent surgery at 4 centers in the U.S. and U.K (average age, 67.2) at a mean 5.5 years after primary TKA. Postoperative distal femoral angle (DFA), proximal tibial angle (PTA), and posterior tibial slope angle (PSA) were radiographically measured, and outliers were recorded. PROMs were compared between patients with aligned versus malaligned knees using univariate analysis., Results: Patients with DFA, PTA, and PSA outliers were more likely to experience similar or decreased activity levels postoperatively than patients with no alignment outliers, as were patients with 1 or 2 outliers of any kind (P < .05). Patients with DFA, PTA, and PSA outliers were significantly more likely to be dissatisfied with their ability to perform activities of daily living (ADLs), as were patients with 1 or 2 outliers of any kind (P < .05). Patients with DFA and PSA outliers were more likely to be dissatisfied with their degree of pain relief, as were patients with 2 outliers of any kind (P < .05). Finally, patients with DFA and PSA outliers, as well as those with 1 outlier of any kind, were more likely to be dissatisfied with their overall knee function (P < .05)., Conclusion: DFA, PTA, and PSA outliers represent a significant risk factor for decreased satisfaction with activities of daily living(ADLs), pain relief, and knee function, as well as decreased activity levels., Level of Evidence: Level III., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: The medial-pivot (MP) design for total knee arthroplasty (TKA) aims to restore more natural "ball-and-socket" knee kinematics compared to the traditional posterior-stabilized (PS) implants for TKA. The objective of this study is to determine if there was any difference in functional outcomes between patients undergoing MP-TKA vs PS-TKA., Methods: This prospective randomized controlled trial consisted of 43 patients undergoing MP-TKA vs 45 patients receiving a single-radius PS-TKA design. The primary outcome was postoperative range of motion (ROM). Secondary outcomes included the Western Ontario and McMaster Universities Arthritis Index, Oxford Knee Score, Knee Society Score (KSS), and radiological outcomes. All study patients were followed-up for 2 years after surgery., Results: Patients undergoing MP-TKA had comparable ROM at 1 year (114.6° ± 16.3° vs 111.3° ± 17.8° respectively, P = .88) and 2 years after surgery (114.9° ± 15.5° vs 114.9° ± 16.4° respectively, P = .92) compared to PS-TKA. There were also no differences in Western Ontario and McMaster Universities Arthritis Index (26.8 ± 19.84 vs 22.0 ± 12.03 respectively, P = .14), Oxford Knee Score (42.7 ± 8.1 vs 42.3 ± 6.7 respectively, P = .18), KSS clinical scores (82.9 ± 16.96 vs 81.42 ± 10.45 respectively, P = .12) and KSS functional scores (76.2 ± 18.81 vs 73.93 ± 8.53 respectively, P = .62) at 2-year follow-up. There was no difference in postoperative limb alignment or complications., Conclusion: This study demonstrated excellent results in both the single-radius PS-TKA design and MP-TKA design. No differences were identified at 2-year follow-up with respect to postoperative ROM and patient-reported outcome measures., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: The use of an extensively porous-coated uncemented cobalt-chrome monoblock femoral stem for revision total hip arthroplasty (THA) is well established with excellent mid-term results. The aim of this study is to report the long-term survivorship of these implants in femoral stem revisions., Methods: This is a long-term retrospective review of prospectively collected data of 55 femoral stem revisions in 55 patients using a contemporary, cementless extensively porous-coated cobalt-chrome monoblock stem. All patients between 2001 and 2006 who underwent first time femoral stem revision with a contemporary, cementless extensively porous-coated cobalt-chrome monoblock stem were included. Harris Hip Score, Western Ontario and McMaster Universities Index, and University of California Los Angeles activity scores were recorded preoperatively and at latest follow-up. Radiographs were analyzed for evidence of loosening, subsidence, osteolysis, and bony union. This study included 55 patients, comprising of 36 females (66%) and 19 males (34%) with a mean age of 66.4 ± 9.3 years at the time of surgery. The mean time interval from index procedure was 9.8 ± 2.9 years. Mean time from revision THA to final follow-up was 13.2 ± 2.17 years with a minimum of 10 years of follow-up., Results: Indications for revision included aseptic loosening (33), prosthetic joint infection (13), and periprosthetic fracture (10). Significant improvement in Harris Hip Score (85.1 ± 1.77 vs 51.8 ± 2.3, P < .001), Western Ontario and McMaster Universities Index (17.6 ± 0.77 vs 33.3 ± 0.8, P < .001), and University of California Los Angeles (5.25 ± 0.2 vs 2.7 ± 0.36, P < .001) scores were found at latest follow-up compared to preoperative. Fifty-four patients (98%) achieved stable bony ingrowth on radiographic analysis. All 10 patients treated for periprosthetic fractures achieved bony union of their fractures. Two patients suffered intraoperative periprosthetic fractures and were treated with a cable-plating system. There were no mechanical failures and no femoral stem re-revisions. One patient was diagnosed with a deep infection and was treated with chronic suppressive antibiotic therapy due to significant medical comorbidities., Conclusion: Revision of the femoral component with a contemporary extensively porous-coated cobalt-chrome femoral stem has excellent functional outcomes, radiographic outcomes, and long-term survivorship with minimal complications., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Advances in perioperative care and growing demand for hospital beds have progressively reduced the length of stay in lower limb arthroplasty. Current trends in population demographics and fiscal climate have also added to this change. Individual institutions have reported good outcomes with outpatient hip and knee arthroplasty. Debate remains regarding the safety of this practice, the optimal protocol, and the applicability in different subsections of population. The primary purpose of this review is to assess the complication and reoperation rates of outpatient arthroplasty., Methods: We performed a systematic review of all papers reporting on 30 and/or 90-day complication rates of outpatient total hip, total knee, and unicondylar knee arthroplasty published from January 1, 2009 to November 1, 2019. Patient demographics, anesthesia, analgesic protocol, selection criteria, and reasons for failed discharge were also extracted., Results: Nineteen manuscripts with a total of 6519 operations between them were analyzed as a part of this systematic review. Mean 90-day readmission rates were 2.3% (range 0%-6%) with 1.61% (range 0%-4%) rate. Overall rate of successful same calendar day discharge was 93.4%. Nausea/dizziness was the most common reason identified (n = 45) for failure of discharge., Conclusion: The patients recruited for outpatient joint arthroplasty were younger, more active, and had suffered from less medical comorbidities than the more typical lower limb arthroplasty patient. There are significant differences in the reported complications between the studies reviewed. More research is needed to establish if an outpatient program can produce similar outcomes to a fast-track program. Further research is also needed to establish the optimal perioperative protocols., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: The objective of this study was to compare macroscopic bone and soft tissue injury between robotic-arm assisted total knee arthroplasty (RA-TKA) and conventional jig-based total knee arthroplasty (CJ-TKA) and create a validated classification system for reporting iatrogenic bone and periarticular soft tissue injury after TKA., Methods: This study included 30 consecutive CJ-TKAs followed by 30 consecutive RA-TKAs performed by a single surgeon. Intraoperative photographs of the femur, tibia, and periarticular soft tissues were taken before implantation of prostheses. Using these outcomes, the macroscopic soft tissue injury (MASTI) classification system was developed to grade iatrogenic bone and soft tissue injuries. Interobserver and Intraobserver validity of the proposed classification system was assessed., Results: Patients undergoing RA-TKA had reduced medial soft tissue injury in both passively correctible (P < .05) and noncorrectible varus deformities (P < .05); more pristine femoral (P < .05) and tibial (P < .05) bone resection cuts; and improved MASTI scores compared to CJ-TKA (P < .05). There was high interobserver (intraclass correlation coefficient 0.92 [95% confidence interval: 0.88-0.96], P < .05) and intraobserver agreement (intraclass correlation coefficient 0.94 [95% confidence interval: 0.92-0.97], P < .05) of the proposed MASTI classification system., Conclusion: There is reduced bone and periarticular soft tissue injury in patients undergoing RA-TKA compared to CJ-TKA. The proposed MASTI classification system is a reproducible grading scheme for describing iatrogenic bone and soft tissue injury in TKA., Clinical Relevance: RA-TKA is associated with reduced bone and soft tissue injury compared with conventional jig-based TKA. The proposed MASTI classification may facilitate further research correlating macroscopic soft tissue injury during TKA to long-term clinical and functional outcomes., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Background: Prevention of dislocation after primary total hip arthroplasty (THA) begins with patient preoperative assessment and planning., Methods: We performed a literature search to assess historical perspectives and current strategies to prevent dislocation after primary THA. The search yielded 3458 articles, and 154 articles are presented., Results: Extremes of age, body mass index >30 kg/m 2 , lumbosacral pathology, surgeon experience, and femoral head size influence dislocation rates after THA. There is mixed evidence regarding the effect of neuromuscular disease, sequelae of pediatric hip conditions, and surgical approach on THA instability. Sex, simultaneous bilateral THA, and restrictive postoperative precautions do not influence the dislocation rates of THA. Navigation, robotics, lipped liners, and dual-mobility acetabular components may improve dislocation rates., Conclusions: Risks for dislocation should be identified, and measures should be taken to mitigate the risk. Reliance on safe zones of acetabular component positioning is historical. We are in an era of bespoke THA surgery., (Copyright © 2018. Published by Elsevier Inc.)

Background: Standard surgical treatment for a periprosthetic knee infection has been based on a staged surgical technique, in order to assure infection eradication prior to implantation of a new prosthesis., Methods: In this article, we discuss our surgical technique in undertaking a single-stage exchange of a chronic knee periprosthetic infection., Results: This technique, which is based on the fundamental principles of controlling infection, preventing recurrence, and restoring function, has been shown to deliver high success rates., Conclusion: As demonstrated, when undertaken under appropriate circumstances, a single-stage exchange combined with local and systemic antibiotic delivery can result in infection eradication comparable to a 2-staged exchange., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: The burden of revision arthroplasty surgery for infection is rising as the rate of primary arthroplasty surgery increases. Infected arthroplasty rates are now relatively low, but the sheer increase in volume is leading to considerable patient morbidity and significant increases in costs to the health care system. Single-stage revision for infection is one of the several accepted treatment options, but the indications and results are debated. This review aims to clarify the current evidence., Methods: MEDLINE/PubMed databases were reviewed for studies that looked at single- or one-stage revision knee or hip arthroplasty for infection., Results: There is increasing evidence that single-stage revision for infection can control infection and with decreased morbidity, mortality, and health care costs compared with a staged approach. However, the indications are still debated. Recently, there has been a determined effort to define an infected arthroplasty in a manner that will allow for standardization of reporting in the literature. The evidence supporting single stage for knee arthroplasty is catching up with the result with hip arthroplasty. High-quality data from randomized controlled trials are now pending., Conclusion: After the gradual evolution of using the single-stage approach, with the widespread acceptance of this definition, we can now standardize comparisons across the world and move toward a refined definition of the ideal patient population for single-stage arthroplasty revision in both the hip and the knee population., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Patellofemoral arthroplasties have been successfully used in the management of isolated patellofemoral joint (PFJ) osteoarthritis (OA). We hypothesized that in posttraumatic PFJ OA, isolated unicompartmental arthroplasty should be associated with reliable pain relief, patient satisfaction, and functional outcome at midterm follow-up., Methods: Fifty-one Avon PFJ (Stryker, Mahwah, NJ) isolated unicompartmental arthroplasties (47 patients; 29 men, 18 women) were identified at a mean follow-up of 7.1 years (range, 5-11 years). The average age at surgery was 57 years (range, 37-69 years)., Results: All patients reported excellent pain relief, satisfaction, and functional outcomes. Median Oxford Knee Score was 38 at latest follow-up with a significant improvement from preoperative scores (P < .0005). There were 2 revisions: 1 for pain and 1 for progression of OA. The probability for survival (Kaplan-Meyer analysis) with revision as end point was 96.1%., Conclusion: The study has shown good midterm results for Avon PFJ (Stryker, Mahwah, NJ) system in posttraumatic PFJ OA, at midterm follow-up in a relatively young patient cohort., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Background: Proximal bony deficiencies present a biomechanical challenge to achieving primary stability in revision hip arthroplasty. Long tapered fluted stems have been engineered to span these defects but concerns of early subsidence are well documented. This work aimed primarily to investigate the issue of subsidence with this design using a cadaveric model. A secondary aim was to compare the stability of 2 versions of this design., Methods: Seven pairs of cadaveric femora were obtained, dual emission x-ray absorpitometry scanned, with calibration radiographs taken for digital templating. Each bone was potted according to the ISO standard for fatigue testing and a Paprosky type 3 defect was simulated. The established cone-conical Restoration Modular (Stryker) system and a novel design with a chamfered tip and flute configuration (Redapt, Smith & Nephew) were examined. Movement at the stem-bone interface was measured using radiostereometric analysis and micromotion transducers., Results: All restoration stems and 85% of the Redapt stems achieved stability by recognized criteria, micromotion < 150 μm and migration less than 2 mm. A Fisher exact test comparing the proportion of stems which were stable or unstable was not significant, P = .055. Mean axial subsidence (SD) was 0.17 mm (0.32) and 0.1 mm (0.131) for the Restoration and Redapt stems respectively., Conclusion: This study has demonstrated minimal subsidence in the immediate post-operative period using tapered fluted stems. Both designs achieved excellent stability despite simulation of Paprosky type 3 bony defects in the cadaveric model. This geometry appears satisfactory for use in revision surgery in the presence of significant proximal bony deficiencies., (Copyright © 2016 Elsevier Inc. All rights reserved.)

The purpose of this study was to measure the time to perform particular activities in the operating room and calculate the cost per minute to perform each activity. We timed how long it takes to perform 15 individual activities carried out by orthopedic trainees during total hip and knee arthroplasty. We developed an algorithm, and then measured the time taken for the preparation of 20 consecutive patients using it. With the algorithm, overall preparation time was reduced by 25.32% for each hip arthroplasty and by 27.60% (P < .0001) for each knee arthroplasty, saving £84.32 and £93.44 per case, respectively. Coordination between surgeons and theater staff is essential to reduce the time spent performing activities, and this will help improve theater efficiency., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Periprosthetic joint infections following hip and knee arthroplasty are challenging complications for Orthopaedic surgeons to manage. The single-stage exchange procedure is becoming increasingly popular with promising results. At our Institute we have demonstrated favourable or similar outcomes compared to the 'gold-standard' two-stage exchange, and other published single-stage results. The aim of this study is to describe the patient selection criteria and perioperative steps in a single-stage exchange for hip and knee arthroplasty undertaken at our Institute. The outlined protocol can be performed using standard debridement, attention to detail and well-recognised reconstructive techniques., (Copyright © 2015 Elsevier Inc. All rights reserved.)

We undertook a systematic review of 11 randomised controlled trials comparing patient outcomes in total knee arthroplasty in those who had undergone pre-operative physiotherapy-based interventions against control groups. Results show that there is little evidence that pre-operative physiotherapy brings about significant improvements in patient outcome scores, lower limb strength, pain, range of movement and hospital length of stay following total knee arthroplasty. The overall quality of the studies was moderate to poor, mostly due to the small sample sizes., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Using the National Joint Registry (UK) database, we compared the thickness of polyethylene (PE) and the level of constraint used during primary total knee arthroplasty (TKA) versus the revision of unicondylar knee arthroplasty (UKA) to TKA. A total of 251,803 TKA procedures and 374 revision UKA-TKA procedures between 2003 and 2009 were reviewed. The commonest PE size used in TKA was 10mm, compared to 12.79 mm in the revision group. The use of constrained knee implant was required in 2.15% of primary TKA and 4.19% of UKA to TKA revisions. The revision of UKA to TKA is a more complex procedure compared to primary TKA, with a higher incidence of using constrained implants and thicker PE inserts. These findings may be useful for surgeons in their decision making., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Host bone contact of less than 50% is perceived but not proven to cause migration and loosening after acetabular revision. A prospective analysis of cementless acetabular revision cases with impaction grafting was performed to determine if this was an independent risk factor for these events. Sixty-two hips in 54 patients were assessed at a mean follow-up of 84.5 months (range 61-112) yielding a probability of 94.6% of retaining the acetabular component using revision for aseptic loosening as the end point. No single factor was independently causative for loosening, although Type III fixation was associated with migration (p=0.0159); subanalysis suggested that achieving host-bone contact in at least part of the dome and posterior column is important., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Third-generation trochanteric fixation cable systems are designed to overcome implant breakage, nonunion, and bony escape. The study prospectively assessed the functional and radiologic outcomes using such an implant. Forty-seven trochanteric fixations in 46 patients were performed over 4 years at 2 institutions using the Accord Cable Plate system (Smith and Nephew, Memphis, Tenn). Serial evaluation at a mean follow-up of 57 months demonstrated that the mean Harris hip scores improved from 52.3 preoperatively to 88.2 postoperatively (P < .001), and the mean pain score improved from 6.2 to 2.3, respectively (P < .001). No cable breakage, fretting, or fraying occurred. There were 2 cases of nonunion. A third-generation cable system appears to improve upon early-generation implants and provide favorable outcomes for reattachment of a trochanteric fragment in a variety of clinical scenarios., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Infected periprosthetic fractures around total hip arthroplasties are an extremely challenging problem. We describe our experience of managing infected periprosthetic femoral fractures using interlocking long-stem femoral prostheses either as temporary functional spacers or as definitive implants. The Cannulock (Orthodesign, Christchurch, United Kingdom) uncoated stem was used in 12 cases, and the Kent hip prosthesis (Biomet Merck, Bridgend, United Kingdom), in 5 cases. Satisfactory outcome was noted in all cases, and in 11 cases, revision to a definitive stem has been undertaken after successful control of infection and fracture union. The use of interlocking stems offers a relatively appealing solution for a complex problem and avoids the complications that would be associated with resection of the entire femur or the use of large quantities of bone cement., (Copyright © 2011 Elsevier Inc. All rights reserved.)

A major concern during revision hip arthroplasty is acetabular bone loss during the extraction of well-fixed acetabular components. Despite the good early survivorship of resurfacing prostheses, revision surgery may be necessary. We recommend the use of the Explant acetabular extraction system (Zimmer, Warsaw, Ind) with a trial liner to preserve acetabular bone stock. We present 2 cases of revised resurfacings using this technique, demonstrating minimal interference to the remaining acetabular bone., (Copyright © 2010 Elsevier Inc. All rights reserved.)

Fourteen patients with a diagnosis of infected total joint arthroplasty treated by 1 or 2-stage revision and a course of oral linezolid were reviewed. Patients were assessed according to McPherson stage, inflammatory markers, nature of surgery, use of antibiotics, pathogen isolated, and outcome at follow-up. Pathogens isolated were coagulase-negative staphylococcus, multiresistant Staphylococcus aureus, Enterobacter cloacae, and mixed growth. McPherson stages were 1 IB2, 1 IA3, 1 II A2, 3IIIA2, 2 IIIB1, 3 IIIB2, 1 IIIB3, 1 IIIC2, and 1 IIIC3. All patients showed resolution of infection, with normalization of inflammatory markers after treatment. Mean length of follow-up is 32.7 months (range, 9-44 months). Comparison is drawn with previous studies highlighting the good results achievable with the use of this antibiotic. Although no substitute for adequate surgical management, it does allow oral treatment and therefore avoids the difficulties associated with long-term intravenous antibiotic therapy.

We compared 28 total hip arthroplasties done in dysplastic hips after previous Chiari osteotomy (group I) with a well-matched control group of 50 primary procedures (group II) done during the same period at an average follow-up of 5 years (range, 25-199 months). Group I required significantly less acetabular augmentation, had significantly shorter operative times, had less intraoperative blood loss, and had fewer complications than group II. There was no significant difference between the 2 groups in terms of clinical or radiographic outcome. Total hip arthroplasty after a successful Chiari osteotomy leads to medium-term results similar to those of other dysplastic hips. In our experience, less bone grafting was required, better coverage of the cup by host-bone was obtained, and the center of motion of the hip was more anatomic. Chiari osteotomy may delay the need for total hip arthroplasty, may facilitate acetabular reconstruction, and does not seem to compromise the medium-term clinical or radiographic outcome., (Copyright 2002, Elsevier Science (USA).)

The differences between the pneumatic compression thromboprophylaxis delivered after elective total hip arthroplasties and that was expected were quantified before (49 patients) and after a concerted nursing education program (30 patients) that was designed to ensure maximum compliance and to verify the correct application of the devices. The expected therapy was not delivered to any of the patients monitored. Therapy was delivered only an average of 77.8% of the time during the expected treatment periods. During 99.9% of the expected therapy times, values of key outcomes-related parameters of the therapy delivered to the patients varied by >10% from expected values. These variations were not reduced significantly by medical and nursing education. This variation may be a significant confounding factor in comparatively evaluating thromboembolic disease outcome reports.

Sixty patients were prospectively assessed using the Western Ontario and McMaster Osteoarthritis Index (WOMAC) scale for osteoarthritis of the hip and the Short Form 36 (SF-36) general health status scale as well as the expectation WOMAC, which asked patients to estimate how they expected to feel 6 months after revision hip arthroplasty. There was a wide range of expectations, but we were unable to find any significant correlation between the patients' preoperative pain and stiffness levels and their expectations for pain and stiffness after revision hip arthroplasty. There was no significant correlation between the SF-36 scores and the patients' expectations. Our findings suggest that the expectations of patients awaiting revision hip arthroplasties are high and are not related closely to the level of preoperative disability.

A total of 50 consecutive knee arthroplasties in 42 patients who had undergone previous high tibial osteotomies have been reviewed with a minimum follow-up of 5 years and compared with 50 age-matched and sex-matched primary total knee arthroplasties. There were no significant preoperative differences between the 2 groups. Surgery in the osteotomy group took on average 23 minutes longer (P < .02), and there was a decrease of 80 flexion postoperatively but without an associated difference in knee scores. Patellar subluxation was also seen more frequently (P < .05). There was no difference in the revision rate at an average follow-up of > 6.2 years. Although there are significant technical difficulties and subtle clinical differences, the overall outcome remains good to excellent in most cases.

Acetabular bone stock deficiency is commonly encountered in revision hip surgery. A number of techniques are available to address this problem, including the use of particulate allograft with reconstruction rings in an effort to provide a stable construct and replenish bone stock. Our technique and results using such devices in complex acetabular deficiencies are described. In the setting of a large nmedial segmental or cavitary acetabular defect, morcellized bone-graft is used to reconstitute the acetabular floor. This graft is reverse reamed until its depth allows screw fixation of a metallic support ring. The screws also serve to compress the graft. A polyethylene acetabular component is then cemented into the reconstituted acetabulum with full freedom of orientation. A series of 48 patients in whom this technique was employed is presented. These cases have been clinically and radiologically reviewed with a mean follow-up of 64 months (range, 25-102 months). Good bony incorporation with stable acetabular components was seen in all but the two cases in which sepsis predominated.