Loosening Of Acetabular Component Research Articles

OUTCOMES OF TRABECULAR METAL IN REVISION ACETABULAR RECONSTRUCTION IN AUCKLAND

IntroductionAcetabular component loosening with associated bone loss is a challenge in revision hip arthroplasty. Trabecular Metal (TM) by Zimmer Biomet has been shown to have greater implant survivorship for all-cause acetabular revision in small cohort retrospective studies. Our study aims to review outcomes of acetabular TM implants locally.MethodThis is a retrospective observational study using data from Auckland City and North Shore Hospitals from 1st of January 2010 to 31st of December 2020. Primary outcome is implant survivorship (re-revision acetabular surgery for any cause) demonstrated using Kaplan-Meier analysis. Secondary outcome is indication for index revision and re-revision surgery. Multivariate analysis used to identify statistically significant factors for re-revision surgery.Results225 cases used acetabular TM implants (shells and/or augments) over 10 years. Indications include aseptic loosening (63%), instability (15%) and infection (13%). Of these, 12% (n=28) had further re-revision for infection (54%) and instability (21%). Median time to re-revision was 156 days (range 11 – 2022). No cases of re-revision were due to failure of bony ingrowth or acetabular component loosening. Ethnicity, smoking status, and age were not risk factors for re-revision procedures. Additionally, previous prosthetic joint infection, ethnicity, sex and age were not significant risk factors for re-revision due to infection. Implant survivorship was 80% at 1 year, 71% at 5 years and 64% at 10 years.DiscussionMain indications for re-revision were infection and instability. Demographic factors and co-morbidities did not correlate with increased re-revision risk. Survivorship is poorer compared to cumulative survivorship reported by the New Zealand Joint Registry (NZJR). Explanations are multifactorial and possibly contributed by underestimation of true revision rates by registry data.ConclusionsWe need to identify alternate causes for poorer survivorship and review the role of TM implants in acetabular revision within our specified population.

Medium- to long-term clinical efficacy of total hip arthroplasty with structural bone grafting for dysplasia of the hip.

Patients with dysplasia of the hip (DDH) have different degrees of bone defects above and outside the acetabulum, and anatomically reconstructing the acetabular centre of rotation is difficult in primary total hip arthroplasty (THA). From April 2012 to December 2022, 64 patients (64 hips) with DDH treated with THA with structural bone graft in the superolateral acetabulum were selected. The Oxford hip score(OHS), Barthel index (BI), leg length discrepancy, Wibegr central edge-angle(CE), gluteus medius muscle strength, vertical and horizontal distance of the hip rotation center, coverage rate of the bone graft and complications were used to evaluate the clinical effectiveness of the patients. All patients were followed up for an average of 7.3±1.9 years. The OHS improved significantly after the operation (P<0.001). The postoperative BI was significantly greater than that before operation (P<0.001). The postoperative leg length discrepancy was significantly lower than that before the operation (P<0.001). Postoperative bedside photography revealed that the height and horizontal distance to the hip rotation center were significantly lower after surgery than before surgery (P<0.001). The postoperative CE was significantly greater than that before surgery (P<0.001). No acetabular component loosening or bone graft resorption was found during the postoperative imaging examination. The use of biological acetabular cup combined with structural bone graft in the superolateral acetabulum in THA for DDH can obtain satisfactory medium and long-term clinical and radiological results.

Acetabular component liner exchange with highly crosslinked polyethylene for wear and osteolysis.

Isolated acetabular liner exchange with a highly crosslinked polyethylene (HXLPE) component is an option to address polyethylene wear and osteolysis following total hip arthroplasty (THA) in the presence of a well-fixed acetabular shell. The liner can be fixed either with the original locking mechanism or by being cemented within the acetabular component. Whether the method used for fixation of the HXLPE liner has any bearing on the long-term outcomes is still unclear. Data were retrieved for all patients who underwent isolated acetabular component liner exchange surgery with a HXLPE component in our institute between August 2000 and January 2015. Patients were classified according to the fixation method used (original locking mechanism (n = 36) or cemented (n = 50)). Survival and revision rates were compared. A total of 86 revisions were performed and the mean duration of follow-up was 13 years. A total of 20 patients (23.3%) had complications, with dislocation alone being the most common (8.1%; 7/86). Ten patients (11.6%) required re-revision surgery. Cementing the HXLPE liner (8.0%; 4/50) had a higher incidence of re-revision due to acetabular component liner-related complications than using the original locking mechanism (0%; 0/36; p = 0.082). Fixation using the original locking mechanism was associated with re-revision due to acetabular component loosening (8.3%; 3/36), compared to cementing (0%; 0/50; p = 0.038). Overall estimated mean survival was 19.2 years. There was no significant difference in the re-revision rate between the original locking mechanism (11.1%; 4/36) and cementing (12.0%; 6/50; p = 0.899). Using Kaplan-Meier survival analysis, the revision-free survival of HXLPE fixed with the original locking mechanism and cementing was 94.1% and 93.2%, respectively, at ten years, and 84.7% and 81.3%, respectively, at 20 years (p = 0.840). The re-revision rate and the revision-free survival following acetabular component liner exchange revision surgery using the HXLPE liner were not influenced by the fixation technique used. Both techniques were associated with good survival at a mean follow-up of 13 years. Careful patient selection is necessary for isolated acetabular component liner exchange revision surgery in order to achieve the best outcomes.

Composite Reconstruction With Irradiated Autograft Plus Total Hip Replacement After Type II Pelvic Resections for Tumors Is Feasible but Fraught With Complications.

Malignancies involving the pelvic ring present numerous challenges, especially in the periacetabular area. Extensive resection of the pelvic region without reconstruction can lead to severe functional impairment. Numerous reconstructive options exist, but all have drawbacks. Extracorporeally irradiated autografts are one option for reconstruction after periacetabular resections; they offer the potential advantages of eliminating the risk of allogeneic reactions associated with allografts and preserving local anatomy. However, little is known about the durability and risks of this approach in pelvic reconstruction. (1) What are the survival rates of the autograft used, and if there is graft loss, what is the extent of this loss? (2) What are the functional outcomes after the implementation of this method? (3) What is the rate and nature of complications associated with this approach? This is a retrospective case series from one subspecialty tumor unit that evaluated patients treated between January 2005 to January 2022. During that time, three surgeons treated 48 patients with Type II resections (defined as resection of periacetabular area). Patients treated with isolated Type II resections were eligible, as were those treated either with Type I+II resections, Type II+III resections, Type I+II+III resections, and Type I+II+III+IV resections. Of those, 21% (10 of 48) were treated primarily with a cone prosthesis, 13% (6 of 48) were treated without femoral reconstruction, 10% (5 of 48) were treated with resection without reconstruction, and 6% (3 of 48) had a THA on the sacrum, leaving 50% (24 of 48) of patients who were treated with femoral and acetabular reconstruction using extracorporeally irradiated autograft and total hip replacement; those patients were potentially eligible for this study. During that time span, we used this approach in all Type II pelvic resection procedures, when a part of the hemipelvis could be preserved without resection (other than Type I+II+III+IV) and where we predicted that there would be sufficient bone stock after tumor removal. Of those, 21% (5 of 24) were lost to follow-up before 2 years, and 13% (3 of 24) died within 2 years with the reconstruction intact and without any reoperation or graft loss, leaving 67% (16 of 24) for analysis here. Demographic characteristics, type of tumor, tumor origin site, type of applied resection, and extent of applied surgical procedure were noted. Of 16 patients, 12 were male, with a mean age of 38 ± 21 years. Tumor types included chondrosarcoma in eight patients, malignant mesenchymal tumor in four patients, osteosarcoma in two patients, and Ewing sarcoma in two patients. Among these, 10 patients had tumors originating from the pelvis, whereas six patients had tumors originating from the proximal femur. We used a Kaplan-Meier estimator to calculate survivorship free from total or partial graft removal at 72 months. To measure functional results, the Musculoskeletal Tumor Society (MSTS) scoring system was utilized at most recent follow-up so as to be able to evaluate the impact of complications (if any) on the ultimate result. The MSTS score ranges from a minimum of 0 points to a maximum of 30 points, where a higher score reflects lower pain and higher functional and emotional capacity. Related complications, time of complications, secondary interventions, and mortality rates were also ascertained from chart review. Graft survival rate at 72 months after initial reconstruction, free from partial or total graft removal, was 50% (95% CI 26% to 75%). Kaplan-Meier analyses revealed estimated mean time of graft removal as 43 months (95% CI 28 to 58). The graft was protected in eight patients on their final follow-up radiographs. The median (range) MSTS score was 18 (6 to 25) of 30 points at most-recent follow-up (these scores include patients who have had their grafts removed). In all, 15 of 16 patients had 17 complications; 16 were major complications (defined as those substantial enough to result in further surgery or a life- or limb-threatening event). A total of 14 of those 15 patients underwent one or more secondary procedures (a total of 21 unplanned additional procedures were performed in those patients). Deep infection was the most common complication, occurring in eight patients. Prosthesis dislocation occurred in four patients. Three patients developed aseptic acetabular component loosening, two had graft fractures, and one patient developed heterotopic ossification. Composite reconstruction with extracorporeal irradiated autografts plus total hip replacement is a feasible reconstruction technique after Type II pelvic resections, although complications and reoperations were common. Although no reconstruction technique has been proven superior to other alternatives, the high risk of complications and reoperations associated with this technique should be considered when selecting from among possible alternative reconstruction methods. Level IV, therapeutic study.

Towards an optimal design of a functionally graded porous uncemented acetabular component using genetic algorithm

Generation of polyethylene wear debris and peri‑prosthetic bone resorption have been identified as potential causes of acetabular component loosening in Total Hip Arthroplasty. This study was aimed at optimization of a functionally graded porous acetabular component to minimize peri‑prosthetic bone resorption and polyethylene liner wear. Porosity levels (porosity values at acetabular rim, and dome) and functional gradation exponents (radial and polar) were considered as the design parameters. The relationship between porosity and elastic properties were obtained from numerical homogenization. The multi-objective optimization was carried out using a non-dominated sorting genetic algorithm integrated with finite element analysis of the hemipelvises subject to various loading conditions of common daily activities. The optimal functionally graded porous designs (OFGPs −1, −2, −3, −4, −5) exhibited less strain-shielding in cancellous bone compared to solid metal-backing. Maximum bone-implant interfacial micromotions (63–68 μm) for OFGPs were found to be close to that of solid metal-backing (66 μm), which might facilitate bone ingrowth. However, OFGPs exhibited an increase in volumetric wear (3–10 %) compared to solid metal-backing. The objective functions were found to be more sensitive to changes in polar gradation exponent than radial gradation exponent, based on the Sobol’ method. Considering the common failure mechanisms, OFGP-1, having highly porous acetabular rim and less porous dome, appears to be a better alternative to the solid metal-backing.

The clinical effect of trochanteric slide osteotomy combined with a cementless femoral conical stem in total hip replacement for the treatment of Crowe type IV developmental dysplasia of the hip.

Total hip replacement (THR) for Crowe type IV developmental dysplasia of the hip (DDH) is still challenging due to specific joint deformities and the high incidence of post-operative complications. This study aimed to evaluate the clinical effect of trochanteric slide osteotomy (TSO) combined with a cementless femoral conical stem in THR for the treatment of Crowe type IV DDH. Thirty-one total hip replacements (26 patients) with Crowe type IV DDH were performed using TSO combined with a cementless femoral conical stem. Surgical outcomes were evaluated using leg length discrepancy (LLD), Harris hip score, and post-operative complications. The average pre-operative LLD was 51mm (range 46-58mm), decreasing to an average of 10mm (range 8-12mm) post-operatively. As a result, the post-operative incidence of the Trendelenburg sign significantly decreased compared with the pre-operative incidence (P< 0.05). Bony union was identified in 26 hips (83.9%), fibrous union in four (12.9%), and non-union in one (3.2%). No acetabular or femoral component loosening, dislocation, or deep infection around the component was found in any of the patients during the follow-up period (27 to 39 months). The average Harris hip score improved from 63.0 ± 3.0 (range 58-69) to 93.3 ± 2.0 (range 91-96). TSO combined with a cementless conical stem in THR is an appropriate option for patients with high congenital hip dislocation.

Outcomes of total hip arthroplasty with a standard prosthesis for the affected hip in patients with poliomyelitis sequelae: a mid-term retrospective follow-up study

IntroductionTotal hip arthroplasty for poliomyelitis sequelae could be a technical challenge due to the higher risk for prosthetic dislocation and degenerative changes in the affected limbs. This study aimed to analyse the mid-term outcomes of primary total hip arthroplasty on the affected hip with standard prosthesis.Materials and MethodsFrom January 2008 to January 2018, 32 patients with poliomyelitis sequelae underwent total hip arthroplasty on the affected hip with standard prosthesis. Clinical and radiographical outcomes, complications, and prosthesis survival rates were evaluated.ResultsAfter a mean follow-up of 7.9 (4.4–13.1) years, the Harris Hip Score, University of California Los Angeles activity level rating, and 12-item Short Form Health Survey Questionnaire scale score significantly improved. The abduction and flexion motions of the hip joint improved dramatically, and the visual analogue scale pain score decreased significantly. The leg length discrepancy was effectively corrected. During the follow-up, one patient experienced prosthetic dislocation, one underwent revision surgery due to acetabular component loosening, two had osteolysis, four had heterotopic ossification, two experienced transient sciatic nerve palsy, and one had intermuscular vein thrombosis. The prosthesis survival rate was 96.9% at 5 years postoperatively. No periprosthetic infection occurred.ConclusionTotal hip arthroplasty with standard prosthesis could be an effective treatment for hip arthropathy on the affected hip of patients with poliomyelitis sequelae, resulting in good clinical outcomes and few complications. Constrained liner and dual mobility articulation are not recommended unless the hip muscle strength of the abductor is < III.

POSITIONING OF ACETABULAR AND FEMORAL COMPONENT IN PRIMARY TOTAL HIP ARTHROPLASTY USING CT EVALUATED PATIENT NATIVE ANATOMY

In total hip arthroplasty, component orientation is an important task for stability. Acetabular and femoral component orientation is the key factor for outcome of total hip arthroplasty. The aim of this study is to assess the clinical and radiological effectiveness of positioning of acetabulum and femoral components in primary total hip replacement using CT evaluated patient native anatomy. Subjects of this study were 36 patients with nonunion neck of femur fractures or arthritic hip based on inclusion and exclusion criteria and treated with cemented or uncemented total hip arthroplasty. Pre operative CT scan with 3D reconstruction was done for all patients and the acetabular inclination and version was measured in coronal and axial planes. Femoral anteversion was measured in mid axial image. Transverse acetabular notch (TAN) and anterior acetabular notch (AAN) were identied intra operatively to reproduce the pre operative angles. Post operatively CT scan was done and all angles were measured as before. All patients were followed up and analyzed using Harris Hip Score. The mean preoperative Harris Hip Score is 34.5. The mean postoperative Harris Hip Score is 88.19. Mean acetabular cup inclination is 39.80°, Mean cup anteversion is 15.1° and mean femoral anteversion is 14.75°. No Dislocation was noted during follow up. No hips show clinical and radiological evidence of femoral and acetabular component loosening. All Postoperative CT measurements of angles are within the safe zone by Lewinnek et al. Preoperative CT guided parameters, intra operative anatomical landmarks (TAN&amp;AAN) and the digital protractor device can aid better positioning of the acetabular and femoral component of THA and is independent of the position of the patient. It also provides a precise planning for component placement resulting in less intra operative time thereby reducing the chances of infection and decreases the dislocation rate and wear and tear and improves the functional outcome

Uncemented total hip replacement with impaction bone grafting in protrusio acetabuli

Protrusio acetabuli is a central acetabular defect resulting from migration of femoral head medial to Kohler’s line. Idiopathic central displacement of femoral head within the acetabulum is quite rare. However, it may be seen in arthritic hips secondary to rheumatoid arthritis, ankylosing spondylitis, previous trauma, osteomalacia, etc. Primary Total Hip Replacement (THR) in such cases is difficult because of the deficient medial bone, decreased peripheral bony support to the acetabular component and proximal and medial migration of the joint centre. Several techniques described previously in the surgical management of protrusio acetabuli include cemented acetabular components with cement alone or in association with morselized bone graft to reconstruct the acetabulum. However, cement has high rates of migration and loosening of cemented acetabular components in young patients leads to more revision surgeries within the first decade of implantation. The purpose of the study is to describe the technique and results of using impacted morselized bone graft with a porous coated cementless acetabular component in patients with protrusio acetabuli.A total of 20 primary THR’s (10 unilateral and 5 bilateral) in 15 patients (8 females and 7 males) with protrusio acetabuli were performed between 2018 and 2021, out of which 4 had mild,7 had moderate and 9 had a severe grade of protrusion. A total of 10 hips were affected by rheumatoid arthritis,3 by ankylosing spondylitis and 7 had unknown etiology. After the surgery, all bone grafts had united by the sixth month with no perceptible change in acetabular component position in any case. The mean preoperative Harris Hip Score was 48 which improved to 82 at the latest follow-up. 45% had excellent,33% had good, and 22% had fair results. There was no dislocation. The use of impacted morselized autograft with a cementless porous acetabular component is a good technique of restoration of hip biomechanics and sound fixation in cases of protrusio acetabuli.

Impaction bone grafting for femoral revision hip arthroplasty with Exeter stem in Japan: An extended 10- to 15-year stem survival analysis of the previously reported series

BackgroundFemoral impaction bone grafting (IBG) was introduced in the late 1990s in Japan and has gradually become recognized as a useful option for femoral revision. The aim of the present study was to retrospectively analyze 10 to 15 years of clinical results of femoral revision arthroplasties of IBG using Exeter stem performed by experienced Japanese surgeons. MethodsWe investigated radiographic and clinical records more than 2 years after surgery in 99 hips of 93 patients. The average age was 66.3 years (36–84 years) and the average follow-up period was 11 years (2–23 years and 8 months). Merle d’Aubigné and Postel hip score was used for clinical assessment, and re-operations for any reason were recorded. The survival curve was estimated using Kaplan-Meier method. ResultsThe mean Merle d’Aubigné and Postel hip score improved from 9.0 points to 14.5 points at the final follow-up. Re-operations were undertaken in 15 hips of 14 patients for aseptic acetabular component loosening (n = 1 hip), recurrent dislocation (n = 2 hips), infection (n = 4 hips), and periprosthetic femoral fracture (n = 8 hips). The survival rates at 10 and 15 years after operation were 87.1% and 81.1% with any type of re-operation as the endpoint, 92.2% and 92.2% with stem removal or exchange as the endpoint, 94.9% and 88.1% with re-operation for periprosthetic femoral fracture as the endpoint, and 99.0% and 99.0% with re-operation for aseptic stem loosening as the endpoint, respectively. ConclusionsThe present study showed encouraging results of femoral IBG over 10 years by experienced surgeons in Japan. Although femoral IBG is recognized as a technically complex procedure, survivorship of the stem is excellent, with a 15-year stem survival rate of 99.0% at the end point of aseptic loosening.

Total Hip Arthroplasty via direct anterior approach for osteonecrosis; comparison with primary hip osteoarthritis in a mid term follow up

BackgroundTo determine the mid-term outcomes of conventional cementless Total Hip Arthroplasty (THA) in patients with avascular necrosis (AVN) of the femoral head and compare to patients with primary hip osteoarthritis (OA). MethodA total of 330 consecutive primary THA procedures (AVN and OA) performed between 2010 and 2013 by a single surgeon and in a single center using the direct anterior approach (DAA) were included. Assessments including SF-36, WOMAC, and Harris Hip Scores (HHS) were retrieved from patients before the surgery and at the latest follow-up. Clinical and functional outcomes were compared between the AVN and OA groups. ResultsA total of 294 consecutive THA (AVN = 107, OA = 187) with 104.4 ± 6.2 months follow-up were analyzed, which AVN patients were significantly younger (32.0 vs. 59.6 y/o). Corticosteroid 34 (31.8%), idiopathic AVN 31 (29.0%) and use of unapproved weight gain supplements (UWGS) 23 (21.5%) were the main reasons for AVN. Despite that preoperative scores were comparable (P > 0.05), the HHS, SF-36, and WOMAC scores are significantly higher in the AVN group after THA surgery (P < 0.05). Moreover, flexion and abduction ROM were significantly higher in the AVN group (P < 0.05). Regarding each complication, no significant difference was observed between groups. In the whole sample, there were 5 (1.7%) revisions due to loosening of acetabular components, all the OA group (P > 0.05). ConclusionConventional cementless THA with highly cross-linked polyethylene provides satisfactory mid-term results in patients with AVN with a low rate of postoperative complications. Compared to primary OA patients, this group reaches superior postoperative scores.

Acetabular fixation in total hip arthroplasty in the previously irradiated pelvis: a review of basic science and clinical outcomes.

Radiation therapy is a common primary, adjuvant, or palliative treatment for many intrapelvic tumors, including primary gastrointestinal, genitourinary, and hematopoietic tumors, as well as metastatic disease to bone. Radiation has well documented microbiologic and clinical effects on bone ranging from radiation osteitis to early degenerative changes of the hip joint and avascular necrosis of the femoral head. Conventional total hip arthroplasty methods have demonstrated high rates of failure in this population, with historical data describing aseptic loosening rates as high as 44-52%, as radiation have been shown to preferentially diminish osteoblast and osteocyte number and function and limit capacity for both cement interdigitation and biologic bony ingrowth. A review of the clinical literature suggests that patients with prior pelvic irradiation are at higher risk for both septic and aseptic loosening of acetabular components, as well as lower postoperative Harris Hip Score (HHS) when compared to historical controls. With limited evidence, trabecular metal shells with multi-screw fixation and cemented polyethene liners, as well as cemented cup-cage constructs both appear to be durable acetabular fixation options, though the indications for each remains elusive. Further prospective data are needed to better characterize this difficult clinical problem.

Trabecular metal augments in severe malignancy-associated acetabular bone loss.

Acetabular reconstruction is a challenging problem in orthopaedic oncology, especially in extended defects (Paprosky Type 3A and Type 3B). In revision total hip arthroplasty (THA), 1 option is trabecular metal (TM) augments with a porous metal acetabular component. This study evaluated the use of TM augments in periacetabular malignant bone disease. 15 patients were identified from our institutional database from 2000 to 2020 with either Paprosky Type 3A or Type 3B acetabular bone loss due to periacetabular malignancies that underwent at least 1 complex THA reconstruction with TM augments. Postoperative complications were documented, and clinical and radiographic outcomes were analysed. Radiological loosening or revision of the acetabular component were defined as endpoints. There were 7 primary and 8 metastatic cancer patients. 5 were Type 3A and 10 were Type 3B defects after tumour resection. The average follow-up time was 23.8 (range 1.5-47) months. 1 patient required revision for acetabular component loosening after 7 months from the initial implantation. An additional 4 patients required surgical intervention for infection, they had stable TM augments at latest follow-up. TM augments with a porous metal acetabular component may be an alternative to the traditional cemented constructs.

A decade of experience in hip arthroplasty in dysplastic coxarthrosis

One hundred ninety two patients, aged 2578, with dysplastic coxarthrosis underwent total hip replacement (46 out of them bilateral). Technical peculiarities of operations were given. Depending on the character and severity of hip damages the implants of various design were used, if necessary the plasty of spongy bone autografts was performed. At follow up under 10 years in 96% of patients the significant improvement of state was noted. In 3 cases revision total hip replacement was performed, i.e. in 2 cases due to acetabular component loosening and in 1 case due to implant loosening

TWO-STAGE REVISION HIP REPLACEMENT PATIENS WITH SEVERE ACETABULUM DEFECT (CASE REPORT)

Favorable short-term results of arthroplasty are observed in 80–90% of cases, however, over the longer follow up period the percentage of positive outcomes is gradually reduced. Need for revision of the prosthesis or it’s components increases in proportion to time elapsed from the surgery. In addition, such revision is accompanied with a need to substitute the bone defect of the acetabulum. As a solution the authors propose to replace pelvic defects in two stages. During the first stage the defect was filled with bone allograft with platelet-rich fibrin (allografting with the use of PRF technology). After the allograft remodeling during the second stage the revision surgery is performed by implanting standard prostheses. The authors present a clinical case of a female patient with aseptic loosening of acetabular component of prosthesis in the right hip joint, with failed hip function of stage 2, right limb shortening of 2 cm. Treatment results confirm the efficiency and rationality of the proposed bone grafting option. The authors conclude bone allograft in combination with the PRF technology proves to be an alternative to the implantation of massive metal implants in the acetabulum while it reduces the risk of implant-associated infection, of metallosis in surrounding tissues and expands further revision options.

The Open Triradiate Cartilage: How Young Is Too Young for Total Hip Arthroplasty?

There is, to our knowledge, no published literature regarding primary total hip arthroplasty (THA) in pediatric patients with an open triradiate cartilage. The purpose of this study was to report the outcomes following primary THA in pediatric patients with open triradiate cartilage at a single intuition. Using a single institution's Total Joint Registry, 12 patients (13 hips) were identified as having undergone primary THA with open triradiate cartilage between the years of 2000 and 2019. The mean age and body mass index of this group were 13.1 years and 25.5 kg/m2, respectively. The cohort was composed of 10 males, and the mean follow up was 5.5 years. Indications for surgery, functional outcomes, and radiographic signs of stable fixation were analyzed. The most common indication for surgery was avascular necrosis secondary to corticosteroid use (31%), followed by avascular necrosis after operative management of slipped capital femoral epiphysis (23%). The proportion of patients able to achieve independent, gait-aid free, ambulation improved from 23% to 100%. Mean postoperative Harris Hip Score was 92.3. All constructs were cementless, and bearing surfaces included ceramic-on-ceramic in 62% and ceramic on highly crosslinked polyethylene bearings in the remainder. Radiographic review at final follow up demonstrated osseointegration in 12 of 13 (92%) acetabular components. Although 1 patient experienced both acetabular component loosening and instability, on separate occasions, there were no incidences of infection, wound dehiscence, thromboembolic events, or failure secondary to wear. In this study, THA in patients with an open triradiate cartilage yielded significant clinical improvement, low complication rates and good initial implant survivorship at early follow up. Awaiting closure of the triradiate cartilage for concerns of decreased fixation and implant survivorship may be unnecessary. Level IV-case series.

Survivorship and Clinical Outcomes of Constrained Acetabular Liners in Primary and Revision Total Hip Arthroplasty: A Systematic Review

BackgroundSeveral studies have evaluated the survivorship and clinical outcomes of constrained acetabular liners (CALs) in complex primary and revision total hip arthroplasty with hip instability; however, there remains no consensus on the overall performance of this constrained implant. We therefore performed a systematic review of the literature to examine survivorship and complication rate of CAL usage. MethodsA systematic review of the literature in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed. A comprehensive search of PubMed, MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews was conducted for English articles using various combinations of keywords. ResultsIn all, 37 articles met the inclusion criteria. A total of 4152 CALs were implanted. The all-cause reoperation-free survivorship was 79.9%. The overall complication rate was 22.2%. Dislocation was the most common complications observed and the most frequent reason for reoperation with an incidence of 9.4% and 9.2%, respectively. Infection after CAL placement had an incidence of 4.6%. The reoperation rate for aseptic acetabular component loosening was 2.9%. Overall, patients had improved outcomes as documented by postoperative hip scores. ConclusionCALs usage have a relatively high complication rate, particularly when compared with current bearing alternatives (dual mobility cups and large diameter femoral heads), however, it remains a valuable salvage procedure in complex patients affected by recurrent dislocation and implant instability. Newer designs have shown reduced impingement and higher survivorship free from dislocation. However, CALs should only be used when the reasons of instability have been correctly recognized and optimized.

Hueter Anterior Approach for Metal-on-Metal Hip Resurfacing Arthroplasty: 555 Cases at a Minimum Five-Year Follow-Up

BackgroundPurpose of this study was to determine implant survivorship and resultant outcomes, including modes of failure, for metal-on-metal hip resurfacing through the Hueter anterior approach (HAA). MethodsRetrospective review of cases from 2006 to 2015, resulted in 555 metal-on-metal hip resurfacing via HAA, mean age 49.4 ± 6.9 years and mean BMI 28.1 ± 5.3. Kaplan-Meier curves were used to assess implant survivorship. Evaluation of technique was based on radiographic assessment of component position at 6 weeks. Patient-reported outcome measures were assessed using 12-Item Short Form Survey 12, University of California Los Angeles activity, Western Ontario and McMaster Universities Osteoarthritis Index, and hip disability osteoarthritis outcome scores. ResultsAt a mean follow-up of 9.18 years, survivorship was 95.0% at 5 years (95% CI: 93.2-96.8 years) and 92.5% at 10 years (95% CI: 90.0-95.0 years); men at 96.1% (95% CI: 94.3-97.9) and 93.8% (95% CI: 91.1-96.5), and women at 88.8% (95% CI: 81.9-95.7) and 85.6% (95% CI: 77.6-93.6), 5 and 10 years, respectively (P = .033). There were 37 revisions to total hips (7%) at a mean time of 3.3 years (SD 2.7). Indications for revision were aseptic loosening of acetabular (n = 12) and femoral component (n = 7) and pseudotumor (n = 6). Radiographic parameters were respectable and consistent, median acetabular inclination angle 41.2° and femoral stem shaft angle 137.7°. Patient-reported outcome measure scores significantly improved and remained stable at 2 and 5 years postoperatively. ConclusionAlthough choice of surgical approach should always be based on surgeon’s technical expertise, this study has shown that HAA is safe and effective for hip resurfacing. Mindful attention to long-term metal ion exposure must still be considered.

Contemporary Porous Titanium Acetabular Components for Total Hip Arthroplasty After Pelvic Radiation

BackgroundPatients undergoing primary total hip arthroplasty (THA) following pelvic radiation have historically had poor survivorship free of aseptic acetabular component loosening. However, several series have reported improved results with tantalum acetabular components. The purpose of this study is to assess implant survivorship, radiographic results, and clinical outcomes of contemporary, porous titanium acetabular components in the setting of prior pelvic radiation. MethodsWe retrospectively reviewed 33 patients (38 hips) with prior pelvic radiation between 2006 and 2016 who underwent primary THA. The mean overall pelvic radiation dose was 6300 cGy with a mean latency period to THA of 5 years. The most common acetabular component was Pinnacle (DePuy Synthes) in 76%. Eight-seven percent of cups were fixed with screws. The mean age at primary THA was 74 years, 76% were male, and the mean body mass index was 30 kg/m2. Mean follow-up was 5 years. ResultsThe 10-year survivorship free of revision for aseptic loosening, free of any revision, and free of any reoperation were 100%, 89%, and 89%, respectively, when accounting for death as a competing risk. There were 3 revisions; one each for taper corrosion, recurrent dislocation, and infection. Radiographically, all cups had evidence of osteointegration and none had radiographic evidence of loosening. The mean Harris Hip Score improved from 50 to 84 postoperatively (P < .0001). ConclusionContemporary porous titanium acetabular components with supplemental screws provided excellent implant fixation in patients with prior therapeutic pelvic radiation. At 10 years, 100% of these components were free of revision for aseptic loosening and 100% were radiographically well-fixed. Level of EvidenceLevel IV, Therapeutic.

One-Stage Total Hip Arthroplasty with Modular S-ROM Stem for Patients with Bilateral Crowe Type IV Developmental Dysplasia.

ObjectiveThe aim of the present paper was to evaluate the results of one‐stage total hip arthroplasty (THA) for patients with bilateral Crowe type IV developmental dysplasia of the hip (DDH).MethodsData for 58 patients (116 hips) with bilateral Crowe type IV DDH who had one‐stage THA performed by the same surgeon during the period of April 2008 to February 2019 were retrospectively reviewed. The mean age of the patients was 37.3 years; 5 were men and 53 were women. All patients underwent THA through the posterolateral approach using the Pinnacle acetabular cup, a ceramic‐on‐ceramic bearing, and the modular S‐ROM stem. Subtrochanteric shortening osteotomy was performed on 86/116 hips. Intraoperative conditions were recorded. Radiographic and functional outcomes were evaluated, and complications were recorded.ResultsAll patients were followed up for an average of 71.3 ± 37.6 months (range, 12–140). The mean operative time was 276.5 ± 57.9 min (range, 175–540). The mean intraoperative blood loss was 933.6 ± 400.8 mL (range, 300–2000). The mean transfusion requirement was 1778 ± 798.0 mL (range, 575–4550). The mean length of hospital stay was 8.6 ± 3.7 days (range, 5–22). At the final follow‐up, no loosening of acetabular and femoral components was observed. No osteolysis and heterotopic ossification occurred. The mean Harris hip scores were improved from 55.4 ± 14.3 preoperatively to 91.3 ± 4.2 postoperatively (P < 0.001) In terms of complications, no perioperative deaths were recorded. Deep vein thrombosis occurred in 1 hip, with no pulmonary embolism. Intraoperative femur fracture occurred in 3 hips, nerve injury in 1 hip, and leg length discrepancy in 1 patient. Postoperative dislocation occurred in 5 hips and nonunion in 1 hip.ConclusionOur data demonstrated that one‐stage bilateral THA for bilateral Crowe type IV DDH is feasible and can effectively restore hip function.