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

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.

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.

Systematic Exposure in Revision Total Hip Arthroplasty: The Posterior Approach.

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.

Management of Severe Acetabular Bone Loss With Chronic Pelvic Discontinuity in Revision Total Hip Arthroplasty.

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.

Early outcomes of a modern cemented total knee arthroplasty : is tibial loosening a concern?

AIMS: Recent total knee arthroplasty (TKA) designs have featured more anatomical morphologies and shorter tibial keels. However, several reports have raised concerns about the impact of these modifications on implant longevity. The aim of this study was to report the early performance of a modern, cemented TKA design. METHODS: All patients who received a primary, cemented TKA between 2012 and 2017 with a minimum two-year follow-up were included. The implant investigated features an asymmetrical tibial baseplate and shortened keel. Patient demographic details, Knee Society Scores (KSS), component alignment, and the presence of radiolucent lines at final follow-up were recorded. Kaplan-Meier analyses were performed to estimate survivorship. RESULTS: A total of 720 of 754 primary TKAs (95.5%) were included with a mean follow-up of 3.9 years (SD 1.3); 562 (78.1%) were cruciate-retaining and 158 (21.9%) were posterior-stabilized. A total of 11 (1.5%) required reoperation for periprosthetic joint infection and seven (1.0%) for aseptic tibial loosening (five cruciate-retaining, two posterior-stabilized). Loosening occurred at a mean of 3.3 years (0.9 to 6.5). There were no cases of loosening in the 33 patients who received a 14 mm × 30 mm tibial stem extension. All-cause survivorship was 96.6% at three years (95% confidence interval (CI) 95.3% to 98.0%) and 96.2% at five years (95% CI 94.8% to 97.7%). Survivorship with revision for aseptic loosening was 99.6% at three years (95% CI 99.1% to 100.0%) and 99.1% at five years (95% CI 98.4% to 99.9%). Tibial components were in significantly more varus in those with aseptic loosening (mean 3.4° (SD 3.7°) vs 1.3° (SD 2.0°); p = 0.015). There were no other differences in demographic, radiological, or surgical characteristics between revised and non-revised TKAs for aseptic loosening (p = 0.293 to 1.00). Mean KSS improved significantly from 57.3 (SD 9.5) preoperatively to 92.6 (SD 8.9) at the final follow-up (p < 0.001). CONCLUSION: This is the largest series to date of this design of implant. At short-term follow-up, the rate of aseptic tibial loosening is not overly concerning. Further observation is required to determine if there will be an abnormal rate of loosening at mid- to long-term follow-up. Cite this article: Bone Joint J 2021;103-B(6 Supple A):51-58.

Soft-Tissue Balancing in Total Hip Arthroplasty.

¼: Appropriate total hip arthroplasty (THA) reconstruction must simultaneously address component position, restoration of biomechanics, and soft-tissue balance. ¼: 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. ¼: Using a systematic approach to soft-tissue balancing in THA enhances the ability to intraoperatively execute the preoperative plan. ¼: 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.

The Dome Technique, an Option for Massive Anterosuperior Medial Acetabular Bone Loss: A Retrospective Case Series.

BACKGROUND: Acetabular bone loss in revision total hip arthroplasty can be very challenging even for fellowship-trained surgeons. Although it is uncommon, massive anterosuperior medial defects may be encountered, but treatment options have been limited and better ones are needed. QUESTIONS/PURPOSES: The primary purpose of this case series is to describe a novel surgical treatment, which we call the dome technique, that can be used to address these challenging defects. The dome technique allows for the systematic reconstruction of massive anterosuperior medial defects of the acetabulum. We sought to illustrate the utility of this procedure in three patients with failed acetabular components and massive anterosuperior medial defects. METHODS: We undertook a retrospective chart review of three patients who had had Paprosky 3B bone defects and undergone revision total hip arthroplasty by the senior author between 2013 and 2016 using the dome technique. The procedure involved the use of tantalum metal augments pieced together to fill the medial defect and recreate the column support needed for jumbo cup placement. The dome technique is unusual because it allows for intra-operative customization to obtain the proper fit. RESULTS: At a mean of 23.6 months' follow-up (range, 10 to 37 months), all patients had good functional outcomes; none was in need of further revision. CONCLUSIONS: In three patients, the dome technique allowed for the anterosuperior column to be recreated by piecing together two porous metal augments to fill the medial bony void and create a stable column for a jumbo cup to be press fit. By recreating the deficient anterosuperior medial bone, the acetabulum can be downsized in a stepwise manner (with further surgery) and reconstructed in a stable fashion. This novel procedure is a unique option for the treatment of this challenging problem.

Adverse Local Tissue Reaction due to Mechanically Assisted Crevice Corrosion Presenting as Late Instability Following Metal-on-Polyethylene Total Hip Arthroplasty.

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.

Acetabular Distraction Technique for Severe Acetabular Bone Loss and Chronic Pelvic Discontinuity: An Advanced Course.

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.

Outcomes of Isolated Head and Liner Exchange Using Large Femoral Heads and Modern Liners in Revision Total Hip Arthroplasty.

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.

Midlevel Providers in Orthopaedic Surgery: The Patient's Perspective.

Background: Midlevel providers (i.e. physician assistants [PAs] and nurse practitioners [NPs]) are being integrated into systems of care due to the exponentially increasing demand for orthopaedic care. There is a lack of studies which investigate orthopaedic patients' perspectives regarding midlevel providers. Methods: An anonymous questionnaire was administered to 538 first-time patients of four orthopaedic surgeons before their new patient visit. Content included patient perspectives regarding: optimal scope of practice, midlevel provider importance in physician selection, and reimbursement equity with physicians. Results: Of 538 consecutive patients, 415 (77%) responded. 57% were female with an average age of 63.9 ± 11.4 years. Most patients (68%) considered the training background of the surgeon's midlevel provider when initially choosing an orthopaedic surgeon. 34% of all patients perceived PAs to be more highly trained than NPs while 17% perceived the opposite. Patients had specific preferences regarding which services should be surgeon-provided: follow-up for abnormal tests (82%), initial postoperative appointment (81%), new patient visits (81%), and determining the need for advanced diagnostic studies (e.g. MRI) (76%). Patients had specific preferences regarding which services could be midlevel-provided: preoperative teaching (73%), minor in-office procedures (65%), long term postoperative appointments (61%), and prescriptions (61%). Patients lacked a consensus on reimbursement equity for midlevel providers and orthopaedic surgeons, despite most patients (78%) reporting the surgeon provides a higher-quality consultation. Conclusions: As health care becomes increasingly consumer-centric and value-driven, a databased utilization of midlevel staff will allow orthopaedic physicians to optimize efficiency and patient satisfaction. Surgeons may consider our results in division of clinical duties among midlevel staff since patients had specific preferences regarding which services should be physician-provided or midlevel-provided. Orthopaedic surgeons may also consider including the midlevel provider in marketing efforts, as most patients considered the midlevel provider's training background when initially choosing a surgeon and perceived PAs to be more highly trained than NPs. Patients lacked a consensus towards reimbursement equity for orthopaedic surgeons and midlevels, despite reporting that the surgeon provides a higher quality consultation. These findings are important as the midlevel workforce grows in response to the rising demand for orthopaedic care.Level of Evidence: IV.

Painful Hip Arthroplasty: What Should We Find? Diagnostic Approach and Results.

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.

Evaluation and Treatment of Patients With Acetabular Osteolysis After Total Hip Arthroplasty.

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.

High Rate of Failure After Revision of a Constrained Liner.

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.

Do Porous Tantalum Metaphyseal Cones Improve Outcomes in Revision Total Knee Arthroplasty?

BACKGROUND: Some authors have advocated for use of porous tantalum metaphyseal cones to manage bone defects during revision total knee arthroplasty (TKA). The purpose of this study is to compare results with porous metaphyseal cones to results with traditional hybrid stem fixation in revision TKA. METHODS: Forty-nine patients undergoing revision TKA with femoral and/or tibial metaphyseal cones (39 tibial only, 3 femoral only, 7 both) were matched by surgical indication to 49 patients undergoing revision TKA with a traditional hybrid stem (non-cone) technique. Clinical and radiographic outcomes were compared at a minimum of two-year follow-up (mean 3.5 years) with adjustment for baseline characteristics. RESULTS: Pre-revision bone defects and most baseline demographics were similar between the cone and non-cone cohorts suggesting appropriate matching. Patients in the non-cone cohort had greater pre- to post-operative increases in Knee Society Score (37.2 ± 18.6 vs 28.4 ± 17.8, P = .010) and Knee Society Functional Score (30.4 ± 24.3 vs 13.1 ± 27.6, P = .003). The cohorts did not differ with respect to complications, subsequent reoperation, subsequent revision, patient satisfaction, tibial overhang, the presence of radio-sclerotic lines, cortical hypertrophy around the stems, or tibial subsidence. CONCLUSION: In this series, metaphyseal cones were not associated with superior outcomes at short-term follow-up. Given the increased cost associated with use of cones compared to traditional techniques, this study cannot support the routine use of metaphyseal cones in revision TKA. Longer-term follow-up will be necessary to determine if construct durability differs over the long term.

Are Revision Hip Arthroplasty Patients at Higher Risk for Venous Thromboembolic Events Than Primary Hip Arthroplasty Patients?

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.

Quantifying Pelvic Motion During Total Hip Arthroplasty Using a New Surgical Navigation Device.

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.

Prevention and Diagnosis of Periprosthetic Knee Infection.

Total knee arthroplasty (TKA) has become an increasingly common treatment option for patients who have debilitating knee arthritis. TKA is a relatively safe and efficient procedure that results in promising outcomes and has a positive effect on a patient's quality of life. More TKAs are being performed annually because the procedure substantially reduces pain and improves functionality; however, as the number of TKAs continues to rise, there is concern for potential complications that may result in prosthetic joint failure. Primary TKA failure may result in revision procedures that have high costs and an increased risk for additional complications. Infection is the second most common cause of primary TKA failure and the single most common cause of revision TKA failure. Surgeons who have a better understanding of the epidemiology, risk factors, and diagnostic modalities associated with periprosthetic knee infection will be able to implement preventive measures and treat patients in whom such a complication occurs.