Trousdale, Robert T.

Background: Osteonecrosis of the hip is the underlying etiology for 3% to 12% of total hip arthroplasties (THAs). Compared with patients who undergo THA because of osteoarthritis, those who do so because of osteonecrosis typically are younger, have a greater number of underlying diagnoses, and have inferior clinical outcomes and implant survivorship. The purpose of this study was to compare the long-term implant survivorship (median follow-up, 10 years), functional outcomes, and radiographic results of contemporary THAs with a highly cross-linked polyethylene (HXLPE) liner between patients with osteonecrosis and those with osteoarthritis. Methods: All patients who underwent primary THA with an HXLPE liner from 1999 to 2007 were identified from our institutional total joint registry. Patients with a primary diagnosis of osteonecrosis were matched 1:1, on the basis of age, sex, and body mass index (BMI), to patients with a diagnosis of osteoarthritis. This resulted in 461 hips in 413 patients with osteonecrosis matched to 461 hips in 427 patients with osteoarthritis (mean age, 59 years; 47% female; and mean BMI, 29 kg/m 2 ). Long-term implant survivorship, patient-reported outcomes, and radiographic findings were compared. In addition, a subgroup analysis of the osteonecrosis group was performed to see whether certain underlying etiologies portended poor outcomes. The median follow-up was 10 years. Results: The 15-year cumulative rates of revision were 6.6% and 4.5% in the osteonecrosis and osteoarthritis groups, respectively (hazard ratio [HR] = 1.8, p = 0.09). The 15-year cumulative rates of any reoperation were 10.5% and 6.4% in the osteonecrosis and osteoarthritis groups, respectively (HR = 2.2, p = 0.008). There were no radiographic signs of component loosening or osteolysis in the entire cohort. Despite a lower median preoperative Harris hip score (HHS) for patients with osteonecrosis, both groups had marked improvements in their scores, which were similar at all time points after surgery. The cumulative rate of reoperations at 15 years was 0% for hips with radiation-induced osteonecrosis, 6.3% for those with alcohol-induced osteonecrosis, 9.0% for those with posttraumatic osteonecrosis, 12.1% for those with steroid-induced osteonecrosis, and 25% for those with idiopathic osteonecrosis. Conclusions: Contemporary THA with an HXLPE liner offers excellent long-term implant survivorship and functional outcomes for patients with osteonecrosis; however, the risk of a reoperation is higher when compared with patients with osteoarthritis. Level of Evidence: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Aims Modular dual-mobility constructs reduce the risk of dislocation after revision total hip arthroplasty (THA). However, questions about metal ions from the cobalt-chromium (CoCr) liner persist, and are particularly germane to patients being revised for adverse local tissue reactions (ALTR) to metal. We determined the early- to mid-term serum Co and Cr levels after modular dual-mobility components were used in revision and complex primary THAs, and specifically included patients revised for ALTR. Patients and Methods Serum Co and Cr levels were measured prospectively in 24 patients with a modular dual-mobility construct and a ceramic femoral head. Patients with CoCr heads or contralateral THAs with CoCr heads were excluded. The mean age was 63 years (35 to 83), with 13 patients (54%) being female. The mean follow-up was four years (2 to 7). Indications for modular dual-mobility were prosthetic joint infection treated with two-stage exchange and subsequent reimplantation (n = 8), ALTR revision (n = 7), complex primary THA (n = 7), recurrent instability (n = 1), and periprosthetic femoral fracture (n = 1). The mean preoperative Co and Cr in patients revised for an ALTR were 29.7 μg/l (2 to 146) and 21.5 μg/l (1 to 113), respectively. Results Mean Co and Cr levels were 0.30 μg/l and 0.76 μg/l, respectively, at the most recent follow-up. No patient had a Co level ≥ 1 μg/l. Only one patient had a Cr level ≥ 1 μg/l. That patient’s Cr level was 12 μg/l at 57 months after revision THA for ALTR (and decreased ten-fold from a preoperative Cr of 113 μg/l). Conclusion At a mean of four years, no patient with a modular dual-mobility construct and ceramic femoral head had elevated Co levels, including seven patients revised specifically for ALTR. While further studies are required, we support the selective use of a modular dual-mobility construct in revision and complex primary THAs for patients at high risk for instability. Cite this article: Bone Joint J 2019;101-B(6 Supple B):57–61.

Background: Periacetabular osteotomy (PAO) is the most common treatment for symptomatic acetabular dysplasia, or developmental dysplasia of the hip (DDH), in skeletally mature patients. The purpose of this multicenter cohort study was to delineate the long-term radiographic natural history of the dysplastic hip following PAO. Methods: We evaluated all patients undergoing PAO from 1996 to 2012 at 3 academic institutions in the United States. Inclusion criteria were PAO for DDH with a minimum 5-year radiographic follow-up. Exclusion criteria were PAO for isolated acetabular retroversion, neurogenic dysplasia, Legg-Calvé-Perthes disease, and prior hip surgery including osteotomies and arthroscopy. There were 288 patients, 83% of whom were women; the mean age and body mass index (BMI) were 29 years and 25 kg/m 2 , respectively. The mean clinical and radiographic follow-up was 9.2 years (range, 5.0 to 21.1 years). Every preoperative and postoperative hip radiograph was assessed to determine the degree of osteoarthritis according to the Tönnis classification. Survivorship was analyzed by multistate modeling, enabling assessment of progression through the Tönnis grades rather than just individual transitions as with Kaplan-Meier techniques. Results: At the time of final follow-up, 144 patients (50%) had progressed at least 1 Tönnis grade, with 42 patients (14.6%) undergoing total hip arthroplasty. The mean number of years spent in each Tönnis grade following PAO was 19 for Tönnis grade 1, 8 for Tönnis grade 2, and 4 for Tönnis grade 3. The probability of progression to total hip arthroplasty increased significantly on the basis of a higher initial Tönnis grade (p < 0.001). The most marked difference occurred between Tönnis grade 0 or 1 and Tönnis grade 2; for Tönnis grade 1, the probability of progression to total hip arthroplasty at 5 and 10 years was 2% and 11%, respectively, compared with 23% and 53%, respectively, for Tönnis grade 2. Conclusions: PAO effectively alters the natural history of DDH. Precise radiographic progression based on the Tönnis grade can now be used to ascribe prognosis for the native hip. Importantly, this investigation demonstrates a stark increase in progression to total hip arthroplasty within 10 years of PAO for patients with preoperative Tönnis grade-2 osteoarthritis compared with those with Tönnis grade-0 or 1 osteoarthritis. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

» Patients with neuromuscular spasticity about the hip with concomitant painful hip arthritis can be effectively treated with total hip arthroplasty, with excellent clinical outcomes and durable implant survivorship. » Certain subsets of patients in this population are at increased risk of dislocation, component loosening, and heterotopic ossification and are also prone to postoperative medical complications. » Strategies that may mitigate the risk of dislocation include using large femoral heads or dual-mobility articulations with cautious use of constrained liners, careful repairing of soft-tissue structures at the conclusion of the surgical procedure, and performing concomitant adductor and flexor tenotomies. In addition, the other common complications can be reduced by coordinating perioperative care with neurological and medical specialists and administering perioperative heterotopic ossification prophylaxis, most commonly in the form of nonsteroidal anti-inflammatory medications, if tolerated.

Background: Cementation of a constrained liner is a viable option for treating instability after total hip arthroplasty (THA) when the acetabular component is well fixed and well aligned. However, concerns regarding long-term mechanical failure and recurrent instability remain. The aim of this study was to evaluate the long-term survivorship, complications, and clinical and radiographic outcomes of constrained polyethylene liners cemented into well-fixed acetabular components at the time of revision THA. Methods: We identified 125 cases in which a constrained liner of 1 design was cemented into a retained, osseointegrated acetabular component during revision THA between 1998 and 2006. The mean patient age at revision was 70 years. Mean follow-up was 7 years. Survivorship data, risk of instability, and clinical and radiographic outcomes were analyzed. Results: Survivorship free from revision for instability was 86% at 5 years and 81% at 10 years. Survivorship free from aseptic acetabular component revision was 78% at 5 years and 65% at 10 years, with the most common failure mechanism being dissociation of the constrained liner from the acetabular component. Survivorship free from revision for any reason was 76% at 5 years and 60% at 10 years. The most common complications were instability and periprosthetic joint infection, with cumulative incidences at 7 years of 18% and 11%, respectively. Harris hip scores did not significantly improve. Cup position did not affect implant survivorship or risk of dislocation. Conclusions: Cementing a constrained liner into a retained acetabular shell at the time of revision THA has durable long-term results, with 8 in 10 patients free from instability at 10 years. Aseptic acetabular survivorship was worse (65%) at 10 years, primarily due to dissociation of the constrained liner from the acetabular component. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Introduction: There is little data regarding timing of index dislocation in patients who undergo primary total hip arthroplasty (THA) and subsequent risk of redislocation and revision. Methods: Between 1992 and 2013, 21,490 primary THAs were performed at a single institution. 189 patients (190 hips) had a first episode of dislocation within one year of index surgery (0.9 %). 32 patients (32 hips) were excluded for the following reasons: complex THA secondary to fracture malunion, Crowe III/IV developmental hip dysplasia, periprosthetic fracture, prior hip surgery, incomplete information, and hip abductor avulsion. The final cohort consisted of 157 patients (158 hips) who experienced dislocation within 1 year of primary non-complex THA. 88 patients were female (56%), mean age was 61 years (SD = 14), and mean follow-up was 76 months (range 0–229). Multivariable Cox proportional-hazards regression models with fractional polynomial models were used to estimate the association between timing of index dislocation and subsequent redislocation and revision surgery. Results: 69 patients (44%) redislocated at final follow-up. Revision for any cause occurred in 26 out of 157 hips (17%). Time lapse from index THA to first dislocation was significantly associated with the risk of redislocation ( p = 0.004) and with the risk of revision ( p = 0.04). For every additional 7 days from surgery, risk of redislocation increased by a factor of 1.1 and risk of revision was increased by a factor of 1.13. Conclusion: This study demonstrates there is a lower risk of redislocation and revision in patients who have a first episode of dislocation closer to primary THA.

Objectives: The Bernese periacetabular osteotomy (PAO) is becoming a widely utilized procedure. Patients are younger, highly active, and may desire to return to sport activity. Counseling and managing expectations in these patients is challenging as there is limited information regarding activity level after PAO. The purpose of this study was to analyze physical activity levels after PAO in a large, prospective multicenter cohort. Methods: Assessment of prospectively collected data from a multicenter group included 456 hips treated by PAO for hip dysplasia. After exclusions, 359 hips (80 male, 279 female) remained with a mean age of 25.9 years and mean BMI of 25. Demographics, radiographic measures, and clinical outcomes were evaluated preoperatively, at 1 year follow-up, and at minimum 2 years postoperatively (mean 44.9 months). Activity level was assessed with the University of California-Los Angeles (UCLA) activity score, patients were stratified into low, moderate, and high activity groups based on preoperative function. Descriptive statistics and linear regressions were performed for the primary outcome of change in UCLA. Results: UCLA scores were improved on average 0.6 points at final follow up (p = 0.001). When stratified, the low activity and moderate activity groups had significant improvement in UCLA scores (p<.0001 and p=0007) while the high activity group saw a decrease in UCLA scores (p<.0001). mHHS, HOOS Pain, and HOOS Sports and Recreation scores were significantly improved across all activity levels. Univariable linear regression analysis identified prior ipsilateral surgery, arthroscopy at time of PAO, and preoperative ACEA to be predictors of the change in UCLA score (p<0.05). With the multivariable model, the effect of prior ispilateral surgery was maintained (p = 0.002). Conclusion: The data suggests that improvements in activity level and function can be expected following PAO surgery, with greater gains experienced by patients with lower preoperative level of activity. [Figure: see text][Figure: see text]

Background: Redislocation of the native hip is rare. An anterior fulcrum between the proximal part of the femur and the pelvis must be present for a posterior dislocation to occur. The purpose of this study is to describe the cases of 9 patients with posterior redislocation or recurrent subluxation of the native hip that was treated with hip preservation surgery. Methods: We retrospectively identified the cases of 9 patients, from 2 institutions, who had undergone hip preservation surgery for the management of posterior redislocation or recurrent subluxation of the native hip after a dislocation. The mean number of dislocations prior to surgery was 3.2 (range, 1 to 7). Pelvic radiographs were used to classify the acetabular morphology, sufficiency of acetabular containment, and structural anatomy of the proximal part of the femur. Radiographic identification of impinging structures was used to guide surgical treatment, which involved either femoral correction alone or the combination of femoral correction and an anteverting periacetabular osteotomy. Results: At a mean follow-up of 73.8 months (range, 10 to 192 months), there had been no subsequent episodes of dislocation or subluxation in any of the hips treated with correction of the anatomic pivot point. An algorithmic approach is presented. Conclusions: In patients who have episodes of redislocation or recurrent subluxation of the native hip, the identification of anatomic abnormalities that create a fulcrum between the proximal part of the femur and the pelvis is critical for making appropriate treatment decisions. Level of Evidence: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Background: Tranexamic acid (TXA) reduces bleeding and the need for transfusion after total knee arthroplasty. Most literature has focused on intravenous (IV) administration of TXA, with less data available on the efficacy of topically administered TXA. This multicenter randomized clinical trial specifically assessed the efficacy of topical TXA compared with IV TXA as measured by calculated blood loss, drain output, and transfusion rates. Complications, including venous thromboembolism (VTE), were reported. Methods: A total of 640 patients who underwent primary unilateral total knee arthroplasty for osteoarthritis at 2 large academic centers were randomized to receive 1 g of IV TXA prior to tourniquet inflation and 1 g at closure, or 3 g of TXA diluted in 45 mL of normal saline solution (total volume of 75 mL) and topically applied after cementation. Age, sex, body mass index, American Society of Anesthesiologists (ASA) score, and preoperative hemoglobin level were similar between the groups. Univariate, multiple linear regression, and multiple logistic regression analyses were performed. Results: Patients who received topical TXA had significantly greater calculated blood loss compared with those who received IV TXA (mean of 324 compared with 271 mL; p = 0.005). Drain output was significantly higher in the topical TXA group compared with the IV TXA group (mean of 560 compared with 456 mL; p < 0.0001). The rate of transfusion was low in the topical and IV groups, with no significant difference on univariate analysis (1.6% compared with 0.6%, respectively; p = 0.45); however, on multiple logistic regression analysis, patients who received topical TXA were 2.2-fold more likely to receive a transfusion (p < 0.0001). The topical and IV TXA groups did not differ significantly with respect to the rate of thrombotic events (0.6% compared with 1.6%, respectively; p = 0.45). Conclusions: In this large, randomized clinical trial involving patients undergoing total knee arthroplasty, both IV and topical TXA were associated with a low rate of transfusion. While IV TXA was associated with less calculated blood loss, lower drain output, and fewer transfusions, the small differences between the groups may not be clinically important. Given the low prevalence of thrombotic complications, the relative safety of one formulation of TXA over the other cannot be definitely established. Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence.