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Background The benefits of HXLPE in total knee arthroplasty (TKA) have not been as evident as total hip arthroplasty (THA). A systematic review and meta-analysis to assess the impact of highly-crosslinked polyethylene (HXLPE) on TKA outcomes compared to conventional polyethylene (CPE) is described. Methods All studies comparing HXLPE with CPE for primary TKA were included for analysis. The minimum dataset included revision rates, indication for revision, aseptic component loosening and follow-up time. The primary outcome variables were all-cause revision, aseptic revision, revision for loosening, radiographic component loosening, osteolysis and incidence of radiolucent lines. Secondary outcome measures included postoperative functional knee scores. A random-effects meta-analysis allowing for all missing data was performed for all primary outcome variables. Results Six studies met the inclusion criteria. In total, there were 2,234 knees (1,105 HXLPE and 1,129 CPE). The combined mean follow-up for all studies was 6 years. The aseptic revision rate in the HXLPE group was 1.02% compared to 1.97% in the CPE group. There was no difference in the rate of all-cause revision (p = 0.131), aseptic revision (p = 0.298) or revision for component loosening (p = 0.206) between the two groups. Radiographic loosening (p = 0.200), radiolucent lines (p = 0.123) and osteolysis (p = 0.604) was similar between both groups. Functional outcomes were similar between groups. Conclusion The use of HXLPE in TKA yields similar results for clinical and radiographic outcomes when compared to CPE at midterm follow-up. HXLPE does not confer the same advantages to TKA as seen in THA.

There is scant literature evaluating varus-valgus constrained (VVC) prostheses in contemporary revision total knee arthroplasty (TKA). Therefore, we aimed to evaluate the durability of VVC revision TKA with selective use of cones.A retrospective review of 194 revision TKAs with VVC was performed from August 2005 through February 2018 at a single institution. The final cohort consisted of 168 TKAs with a mean follow-up of 6 years. Stems were used in all but 1 TKA, tibial cones in 48%, and femoral cones in 19%. Anderson Orthopaedic Research Institute classification in femurs was 1 in 57, 2A in 33, 2B in 62, 3 in 16, and in tibias, 1 in 42, 2A in 29, 2B in 81, and 3 in 16.Survival analysis showed that 93% were free of revision for aseptic component loosening, 76% were free of revision for any reason, and 74% were free of reoperation at 6 years. Anderson Orthopaedic Research Institute 3 femur or tibia, age65 years, and progressive radiographic changes were associated with an increased risk of revision for aseptic loosening (P.05). Progressive radiographic changes were seen in 19% of femoral and 16% of tibial constructs. The most common reason for re-revision was periprosthetic joint infection (65%).VVC revision TKA with selective use of cones provided a reasonable outcome as 93% were free of revision for aseptic loosening at 6 years. However, given the rate of patients with progressive radiographic changes and survivorship free of reoperation of 74% at 6 years, long-term follow-up will help assess the durability of these constructs.

Background Total elbow arthroplasty (TEA) has a higher rate of revision and complications than other total joint arthroplasties. Salvage options for failed TEAs are limited, especially when patients have poor ulna bone stock. The purpose of this study is to describe a surgical technique and report outcomes of patients who underwent revision TEA with implantation of the ulnar component into the radius to address ulna bony defects. Methods A retrospective review of 5 patients at a single institution from 2014 to 2019 in which the ulnar component was implanted into the radius to address large bony defects in the setting of revision TEA was performed. Results At follow-up of 2.1 ± 1.9 years, patients experienced an increase in total arc of motion from 86 ± 17° to 112 ± 8°, with infection eradication and no instances of distal component loosening. Conclusion This salvage technique was effective at providing a stable elbow in patients with large ulna bony defects as a result of prosthetic joint infection or periprosthetic fracture.

Background When revision elbow arthroplasty is required in the presence of structural proximal ulnar bone loss and triceps insufficiency, structural ulnar bone-grafting and triceps reconstruction are both required to reconstruct the skeleton and to restore active extension. We have developed a technique utilizing a structural proximal ulnar allograft with its attached triceps as an allograft-prosthetic composite (APC) to provide reconstruction of the proximal ulnar bone and deficient extensor mechanism with the same allograft. Methods Between 2010 and 2017, the senior author performed 10 revision elbow arthroplasties using a proximal ulnar allograft with its intact triceps tendon allograft. The allograft ulna was combined with an ulnar component in an APC fashion, whereas the remaining triceps was repaired to the triceps allograft. Indications for a revision surgical procedure included aseptic loosening in 4 elbows, periprosthetic ulnar fracture with component loosening in 2 elbows, and the second stage of a 2-stage reimplantation in 4 elbows. Two elbows also required humeral APCs due to associated structural humeral bone loss. Postoperatively, all elbows were immobilized in extension for 6 weeks. The mean follow-up time was 45 months (range, 24 to 76 months). Results Revision elbow arthroplasty resulted in pain improvement in all elbows in a 10-point visual analog scale. The mean flexion-extension arc was 95°, the mean Mayo Elbow Performance Score was 76 points (range, 45 to 95 points), and the mean triceps strength score was 4. There were 6 reoperations: 3 for humeral loosening, 1 for deep infection, 1 for fracture of the ulnar allograft, and 1 for wound debridement and closure. For the 8 elbows with an intact ulnar reconstruction, no ulnar components were radiographically loose, and the ulnar graft was considered radiographically intact and healed in 8 elbows. Conclusions Reconstruction of the proximal part of the ulna and triceps in failed elbow arthroplasties with structural ulnar bone loss can be effectively accomplished using a structural proximal ulnar allograft as an APC with the preserved triceps tendon for the extensor mechanism reconstruction, but the procedure is associated with an expected high reoperation rate, as is the case in complex revision elbow arthroplasty. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Unicompartmental knee arthroplasty (UKA) has become increasingly more common, indicating the necessity to better understand factors that may impact outcomes and survivorship. Overcorrection or undercorrection of a varus deformity can increase the risk of postoperative complications including contralateral, lateral compartmental osteoarthritis, component loosening, and component wear following medial UKA. There is no general consensus on the amount of alignment correction to optimise outcomes. The purpose of this article is to provide an overview of the current literature related to alignment, intraoperative alignment correction, and the impact on outcomes and survivorship following medial UKA as well as to explore alternative surgical techniques including patient-specific instrumentation and robotic assistance when managing the varus-malaligned knee with medial UKA. Understanding each of these factors and how they interact is vital in providing patients with promising outcomes following UKA. The ideal alignment is unknown; however, the key is to avoid severe undercorrection and overcorrection of varus malalignment for superior outcomes following medial UKA.

A 56-year-old male laborer with severe superior and medial acetabular protusio was treated with a cementless left total hip arthroplasty (THA) using an inexpensive technique that preserved the incarcerated femoral head in situ. The head was never dislocated, so the ligamentum was not disrupted. Wires stabilized the femoral head while reaming to prevent it from spinning, and multiple screws united the cup, autograft, and pelvis. At 2-year follow-up, the patient has pain-free hip function, radiographic union, and no component loosening or graft resorption. Keywords: Total hip arthroplasty, Acetabular protrusio, Femoral head bone autograft, Acetabular augment

Bone scintigraphy (BS) is frequently ordered to investigate cause of failure following total knee arthroplasty (TKA). Its correlation of component loosening with intraoperative findings (IFs) at the time of revision TKA (rTKA) has not been well studied. This study investigated correlations between the preoperatively obtained radiologist report (RR) of BS, preoperatively documented surgeon prediction (SP) of component loosening, and operative reports documenting IFs.Our institutional database was retrospectively reviewed for all rTKA done after BS and revealed 96 eligible cases. The RR and SP cohorts were subdivided into all potential combinations of component loosening and were then compared with each other as well as IF. In addition to calculating the percentage correct of RR and SP compared with IF, the levels of agreement between RR and SP were compared using the kappa statistic.Of the 96 cases, the RR correctly correlated with IF in 35 cases (37%), whereas the SP was correct in 66 cases (69%), indicating the preoperative interpretation of the surgeon regarding component loosening at rTKA was correct more frequently (P.001). The kappa statistic between RR and IF was only 0.23 (95% confidence interval [CI] = 0.15-0.32), indicating minimal agreement. The kappa statistic between SP and IF was 0.57 (95% = CI 0.46-0.68), indicating weak agreement. Furthermore, the kappa statistic between RR and SP was 0.36 (95% CI = 0.27-0.45), also indicating minimal agreement.In rTKA, there is weak agreement regarding component loosening between a radiologist's opinion of a preoperatively obtained bone scan and the surgeon's preoperative interpretation of clinical and radiographic data. While neither reliably accurately predicts what is found at the time of rTKA, the surgeon's preoperative interpretation is more closely correlated with actual IFs of component loosening.

As shoulder arthroplasty becomes increasingly common, the burden of revision shoulder arthroplasty is also increasing. Revision reverse shoulder arthroplasty requires an understanding of the causes of failure and the evaluation of these causes and their sequelae, including infection, instability, component loosening, humeral bone loss, and glenoid bone loss. Revision reverse shoulder arthroplasty is technically complex. On the humeral side, corticotomy may be required for component removal, and bone grafting may be necessary to achieve rotational stability and to restore humeral length and avoid undertensioning and instability. On the glenoid side, bone loss is common, structural bone grafting is not infrequently required, and proper component positioning is required to avoid impingement and component loosening. Although the outcomes are generally inferior to primary reverse total shoulder arthroplasty and complications and revision surgeries are common, revision procedures still lead to notable improvements in pain, motion, and function.

Background The Universal 2 is a widely used total wrist implant that aims to maintain function of the wrist. Purpose Promising mid-term results of the Universal 2 total wrist implant are described in the literature. This study evaluates the long-term results in terms of implant survival and patient satisfaction. Patients and Methods Patients who received a Universal 2 implant between 2004 and 2009 were retrospectively identified through a database search. Clinical outcome and complications of the implant were assessed by examination of the patient's medical records, X-rays, and a questionnaire, consisting of the Patient-Rated Wrist and Hand Evaluation questionnaire (PRWHE) and Quick Disabilities of the Arm, Shoulder and Hand (QuickDASH) questionnaires and additional questions. Results Twenty-five patients (26 wrists) were included in this study. Twenty-one (81%) Universal 2 implants remained in situ after a mean follow-up of 11 years. Moderate PRWHE (44) and QuickDASH (41) scores were found in these cases. Five Universal 2 implants failed and were converted to a total wrist arthrodesis after a mean period of 9.2 years due to distal component loosening (n = 3), recurrent luxation (n = 1), or recurrent synovitis (n = 1). Twenty-three (92%) patients were (very) satisfied with the Universal 2 implant. Conclusion The Universal 2 demonstrates a high (81%) implant survival with a high patient satisfaction after a mean follow-up of 11 years. Prospective studies of the Universal 2 implant are necessary to objectify improvement in wrist function and to provide a better comparison to other fourth generation wrist implants.

Introduction Total knee arthroplasty (TKA) is one of the most common orthopedic procedures performed in the United States. Obtaining radiographs in the post-anesthesia care unit (PACU) has been the standard of care at most hospitals. The purpose of this study was to examine the utility and cost-effectiveness of immediate, postoperative radiographs in regards to operative decision-making to prevent complications within 90 days after primary TKA. Methods A retrospective review of 4,830 consecutive patients who underwent cemented or uncemented TKA between January 2016 and June 2019 at a large, regional medical center was performed. International Classification of Diseases, Tenth Revision (ICD-10) codes were used to track any readmissions within 90 days of TKA. If readmission was for a mechanical complication, including fracture, dislocation, or component loosening, PACU radiographs were reviewed for any abnormalities that may have prevented readmission. Results There were 195 readmissions (195 patients), of which 17 were due to mechanical complications. There was no evidence of fracture or abnormality appreciated on any of the reviewed PACU radiographs by either the reading radiologist or the senior authors. Assuming all fractures were noted on immediate, postoperative radiographs, the cost associated with identifying a single fracture in 2,415 patients was $1,072,260. Conclusion Routine radiographs in the recovery room after an uncomplicated primary TKA are not a reliable mechanism for preventing mechanical complications and do not alter patient care.

Background: The radiological phenomenon of subsidence following the implantation of uncemented short-stem reverse prostheses (USSP) has not yet been described. The purpose of this study was to describe the rate and potential risk factors for subsidence. We hypothesized that subsidence may be a frequent finding and that a subsidence of &gt, 5 mm (mm) is associated with an inferior clinical outcome. Methods: A total of 139 patients with an average age of 73 &plusmn, 9 years were included. The clinical and radiological outcome was evaluated at a minimum follow-up (FU) of 12 months. Results: No humeral component loosening was present at a mean FU of 18 (range, 12&ndash, 51) months. Mean Constant Score (CS) and Subjective Shoulder Value (SSV) improved significantly from 34.3 &plusmn, 18.0 points and 37.0 &plusmn, 19.5% preoperatively to 72.2 &plusmn, 13.4 points and 80.3 &plusmn, 16.5% at final FU (p &lt, 0.001). The average subsidence of the USSP was 1.4 &plusmn, 3.7 mm. Subsidence of &gt, 5 mm was present in 15 patients (11%). No association between a subsidence &gt, 5 mm and CS or SSV was found (p = 0.456, p = 0.527). However, a subsidence of &gt, 5 mm resulted in lower strength at final FU (p = 0.022). Complications occurred in six cases (4.2%), and the revision rate was 3.5% (five cases). Conclusions: Although subsidence of USSP is a frequent radiographic finding it is not associated with loosening of the component or a decrease in the clinical outcome at short term FU. Level of evidence: Level 4, retrospective study.

Background In cases of Oxford unicompartmental knee arthroplasty (UKA), an increase in anteroposterior and medial-lateral length is usually disproportional when comparing AA and A-sized tibial components. Asynchronous increments may cause tibial keel impingement leading to complications. Methods Radiographic measurements were performed in five patients with AA-sized tibial implants. The posterior cortex of proximal tibia had two angles recorded as ∠ M1 and ∠ M2. The minimum distance between the tibial component keel and outer margin of the posterior tibial cortex (mDKC) was measured, and the correlation between the preoperative posterior slope angle (PSA), ∠ M1, and mDKC was analyzed. Results All patients showed an acceptable component positioning. Only one patient had an mDKC of < 4 mm that fulfilled the criteria for the posterior tibial cortex at risk. The patient had an increased PSA and ∠ M1 compared to other patients. A negative correlation was found between preoperative PSA and mDKC (r = − 0.935, p = 0.0193); and ∠ M1 and mDKC (r = − 0.969, p = 0.0032). However, no stem tip pain, periprosthetic fracture, or component loosening were observed. Conclusions The distance between the tibial keel and posterior tibial cortex was reduced in AA-sized patients with a large PSA and ∠M1; therefore, the risk of the tibial cortex injury should be considered.

Owing to the improved understanding of knee kinematics and the successful introduction of the kinematic alignment (KA) technique for implanting total knee arthroplasty (TKA), it was recently understood that the “Cartier angle technique” corresponds to a kinematic implantation of the uni-compartmental knee arthroplasty (UKA) components. When compared to the universally spread mechanical alignment (MA) technique for implanting UKA, the KA method generates a more anatomic prosthetic knee that may be clinically advantageous. The aims of this study are to determine if KA UKAs are associated with acceptable functional performance and patient satisfaction (question 1), rates of residual pain and tibia plateau fracture (question 2), and rates of reoperation and revision (question 3), and to define the component orientation and limb alignment as measured on radiograph (question 4), and the stress shielding related bone loss in the proximal tibia (question 5) with KA UKA, and where possible to compare with MA UKA. KA UKA generates good clinical outcomes, similar or superior to the ones of MA UKA. Systematic review of literature databases were primarily searched using Healthcare Databases Advanced Search (HDAS). Two primary searches were conducted using the electronic databases MEDLINE, EMBASE, and PubMed, and a secondary search was conducted using review articles and bibliography of obtained papers in order to ascertain more material. Nine eligible non-comparative prospective (3) or retrospective (6) cohort studies, which cumulated 593 KA UKAs with follow-up between 3.2 and 12 years, fulfilled the inclusion criteria for this systematic review. The findings demonstrated high Knee Society Score (KSS) (from 87 to 95) and function scores (from 81 to above 91) in addition to patient satisfaction scores of 88%. There was no revision for tibia plateau fracture, 0.8% (5 cases) for unexplained pain tibia, 2.0% (12 cases) for component loosening, and 5.6% (33 cases) for any causes of aseptic failures reported for KA UKA. The prosthetic lower limb and tibia implant alignments were both found to be in slight varus (means between 3 and 5°), and the postoperative joint line and tibia component was shown to be parallel to the floor when standing. The KA UKA components migration, as measured on radiostereometry, was acceptable. The KA technique is an alternative, personalised, more physiological method for implanting UKA, which could be clinically advantageous when compared to the MA technique. The literature supports the good mid- to long-term clinical safety and good efficacy of KA UKA; however, comparison between KA and MA techniques for UKA was not performed due to limited literature. Further investigations are needed to better define the clinical impact of KA UKA, and the acceptable limits for KA of the UKA tibial component. Level 4; systematic review of level 4 studies.

Background Revisions of total elbow arthroplasties (TEAs) are commonly performed because of prosthetic loosening. UK National Joint Registry data show that TEA revisions are becoming increasingly common, with 123 TEA revisions performed in 2018 and 76 performed in 2017. TEA radiologic assessment is based on subjective interpretation with no published criteria. We defined TEA loosening by the presence of at least one of the following criteria: (1) progressive widening of the bone-cement, bone-prosthesis, or cement-prosthesis interface; (2) fragmentation or fracture of cement; (3) prosthetic component migration; and (4) bead shedding in porous-coated prostheses. Using this definition, we looked at interobserver and intraobserver agreement on radiologic loosening and compared this assessment with intraoperative findings. Methods In our tertiary care center, we conducted a retrospective review to identify TEA revisions performed between November 2008 and July 2018. Radiologic implant loosening was independently assessed by 5 orthopedic surgeons. Interobserver agreement (κ coefficient) was calculated. The majority’s view of radiologic loosening was compared with intraoperative findings. Results We identified 93 sets of radiographs with implant stability clearly documented in their operative notes. The κ coefficient between assessors for humeral implant loosening was 0.87 (almost perfect). The κ coefficient for ulnar loosening was 0.75 (substantial). The κ coefficients for radiologic and intraoperative findings of humeral loosening and ulnar loosening were 0.67 and 0.71 (substantial), respectively. Intraobserver reliability was almost perfect for humeral loosening (κ = 0.86) and substantial for ulnar loosening (κ = 0.74). Conclusion Our definition of loosening provides reproducible interobserver and intraobserver agreement on radiographic component loosening. In our center’s experience, radiologic findings may not translate to intraoperative findings, and we would advise that surgical strategies for TEA revision include the possibility of needing to perform a dual-implant exchange.

Purpose Low-field MRI, allowing imaging in supine and weight-bearing position, may be utilized as a non-invasive and affordable tool to differentiate between causes of dissatisfaction after TKA (‘problematic TKA’). However, it remains unclear whether low-field MRI results in sufficient image quality with limited metal artefacts. Therefore, this feasibility study explored the diagnostic value of low-field MRI concerning pathologies associated with problematic TKA’s’ by comparing low-field MRI findings with CT and surgical findings. Secondly, differences in patellofemoral parameters between supine and weight-bearing low-field MRI were evaluated. Methods Eight patients with a problematic TKA were scanned using low-field MRI in weight-bearing and supine conditions. Six of these patients underwent revision surgery. Scans were analysed by a radiologist for pathologies associated with a problematic TKA. Additional patellofemoral and alignment parameters were measured by an imaging expert. MRI observations were compared to those obtained with CT, the diagnosis based on the clinical work-up, and findings during revision surgery. Results MRI observations of rotational malalignment, component loosening and patellofemoral arthrosis were comparable with the clinical diagnosis (six out of eight) and were confirmed during surgery (four out of six). All MRI observations were in line with CT findings (seven out of seven). Clinical diagnosis and surgical findings of collateral excessive laxity could not be confirmed with MRI (two out of eight). Conclusion Low-field MRI shows comparable diagnostic value as CT and might be a future low cost and ionizing radiation free alternative. Differences between supine and weight-bearing MRI did not yield clinically relevant information. The study was approved by the Medical Research Ethics Committees of Twente (Netherlands Trial Register: Trial NL7009 (NTR7207). Registered 5 March 2018, https://www.trialregister.nl/trial/7009).

Background It is often challenging to decide whether to revise only the bearing or femoral acetabular component in the setting of progressive osteolysis without component loosening in revision total hip arthroplasty (THA). In this study, we aimed to (1) compare the survivorship of isolated bearing exchange and single/both component revision for patients with periprosthetic osteolysis without component loosening, and (2) identify potential risk factors associated with failures of isolated bearing exchange. Methods A total of 228 consecutive cases of revision THA for progressive osteolysis without component loosening was evaluated in 2 groups: (1) 124 component revision and (2) 104 isolated bearing exchange. The primary outcome was survival, with failure defined as repeat revision or reoperation for any reason. Patient risk factors, such as demographics and medical comorbidities, were also analyzed. Results There was no significant difference in survivorship between the component revision group and the bearing exchange group at 10 years (85% vs 82%; P = .89). There was no progression of osteolysis on radiographs at last follow-up for patients with isolated bearing change. Univariate regression modeling demonstrated that renal disease was associated with failure of isolated bearing exchange after revision THA. Conclusion This study demonstrated that isolated bearing exchange is associated with similar outcomes compared with component revision for aseptic osteolysis without loosening, demonstrating that isolated bearing exchange is a viable option for selected patients with osteolysis in the setting of well-fixed THA components. This provides clinically useful information for surgeons in the surgical treatment of THA patients with wear and osteolysis without component loosening.

Arthroscopy is a powerful tool in the management of the painful total shoulder arthroplasty and should be considered when evaluating cases in which a clear cause of pain is not present. Patients may present with a painful shoulder arthroplasty due to a number of causes-occult infection, instability, component loosening, malposition, or rotator cuff pathology. In certain cases, advanced imaging may not be diagnostic, given the presence of metal artifact. It is our routine clinical practice to evaluate arthroscopically such cases in which the diagnosis is not readily evident. The most common indication for shoulder arthroscopy is pain with no clear cause or loss of motion (39%), followed by biopsy to rule out occult infection (25%), and finally rotator cuff assessment (19%).

Background Patients missing the distal humeral condyles are prone to premature bushing wear after total elbow arthroplasty. A midterm study has demonstrated that a custom triflange outrigger ulnar component was successful in preventing this. The aim of this study was to determine whether these results remained stable over time. Materials and methods The outcomes of 6 patients who underwent revision of a loose ulnar component using a custom triflange outrigger component were reviewed in this retrospective case study. The average patient age at the time of revision was 51. The average number of prior operations was 2 (range, 1-3). The mean follow-up was 15 years (range, 10-18 years). Results At final follow-up, the mean range of extension-flexion was 35° to 135°, and pronation-supination was 65° to 63°. The average Mayo Elbow Performance Score improved to 75 of 100. Four implants were still in place with no radiolucencies or osteolysis. Three patients required revision surgery for broken humeral stems. Two required conversion to another total elbow arthroplasty system after 18 and 14 years for humeral component loosening. Conclusions These components lasted an average of 4 times longer than the original ulnar components. In our experience, periarticular osteolysis caused by polyethylene wear creates a region of unsupported stem and a stress riser at the junction with the remaining well-supported stem and causes component stem fractures. The concept of an outrigger type of hinge might be useful for active patients requiring an elbow prosthesis in the setting of deficient condyles.

Background Non-cemented acetabular cup components demonstrated different clinical performance depending on their surface texture or bearing couple. However, clinical osseointegration needs to be proved for each total joint arthroplasty (TJA) design. Aim of this study was to detect the in vivo migration pattern of a non-cemented cup design, using model-based roentgen stereophotogrammetric analysis with elementary geometrical shape models (EGS-RSA) to calculate early cup migration. Methods Interchangeable applicability of the model-based EGS-RSA method next to gold standard marker-based RSA method was assessed by clinical radiographs. Afterwards, in vivo acetabular cup migration for 39 patients in a maximum follow up of 120 months (10 years) was calculated using model-based EGS-RSA. Results For the axes with the best predictive capability for acetabular cup loosening, mean (±SD) values were calculated for migration and rotation of the cup. The cup migrated 0.16 (±0.22) mm along the cranio-caudal axis after 24 months and 0.36 (±0.72) mm after 120 months, respectively. It rotated − 0.61 (±0.57) deg. about the medio-lateral axis after 24 months and − 0.53 (±0.67) deg. after 120 months, respectively. Conclusions Interchangeable applicability of model-based EGS-RSA next to gold standard marker-based RSA method could be shown. Model-based EGS-RSA enables an in vivo migration measurement without the necessity of TJA specific surface models. Migration of the investigated acetabular cup component indicates significant migration values along all the three axes. However, migration values after the second postoperative year were within the thresholds reported in literature, indicating no risk for later aseptic component loosening of this TJA design.

Ultraporous acetabular components were developed to improve osseointegration and fit for increased longevity and better outcomes after total hip arthroplasty. There is a paucity of literature detailing this acetabular component’s clinical performance, with even less detailing those with screw fixation. We identify 5 patients at our institution who underwent revision total hip arthroplasty for early aseptic acetabular cup loosening of an ultraporous acetabular component known as the Tritanium primary cup with secondary screw fixation. They all presented with groin and hip pain after index surgery and underwent follow-up radiographic examination consistent with component loosening requiring revision surgery. This case series reports on the risk of early acetabular cup loosening and its associated clinical presentation, workup, and surgical management in patients with the Tritanium primary cup augmented with screws.

Background Glenoid component loosening is a common failure mode of total shoulder arthroplasty (TSA). A larger critical shoulder angle (CSA) may cause superior glenoid component loading and more rapid component loosening. The purpose of this study was to define the relationship between the CSA and glenoid component loosening in midterm follow-up after TSA. Methods We conducted a retrospective study of 61 primary TSAs for osteoarthritis with an average follow-up of 5.0 ± 2.2 years without surgical revision. Standard true anteroposterior radiographs postoperatively and at longest follow-up were graded in a blinded and repetitive nature for pegged glenoid radiolucent lines and measured for the CSA. An “at-risk” glenoid was defined as grade 3 or higher lucency. Results The average CSA was 32° ± 5°, median midterm lucency grade was 2 (range, 0-5), and median progression of lucency grade was 1 (range, −1 to 4). At midterm follow-up, 20% of TSAs were grade 3 or higher mean glenoid lucency, with an average CSA of 36°. There was a statistically significant correlation between CSA and both glenoid lucency grade (odds ratio, 1.20 per degree CSA) and progression of lucency grade (odds ratio, 1.24). An increase in CSA of 10° was associated with a 6.2-fold increased odds of having an at-risk glenoid. Conclusion This study identifies the CSA as a risk factor for glenoid component loosening after TSA. Our findings suggest that the CSA may be a modifiable factor during surgery to improve glenoid component outcomes.

Reverse total shoulder arthroplasty (RTSA) is an established treatment for elderly patients with irreparable rotator cuff tears, complex proximal humerus fractures, and revision arthroplasty; however, with the increasing indications for RTSA over the last decade and younger implant recipients, post-operative complications have become more frequent, which has driven advances in computational modeling and simulation of reverse shoulder biomechanics. The objective of this study was to provide a review of previously published studies that employed computational modeling to investigate complications associated with RTSA. Models and applications were reviewed and categorized into four possible complications that included scapular notching, component loosening, glenohumeral joint instability, and acromial and scapular spine fracture, all of which remain a common cause of significant functional impairment and revision surgery. The computational shoulder modeling studies reviewed were primarily used to investigate the effects of implant design, intraoperative component placement, and surgical technique on postoperative shoulder biomechanics after RTSA, with the findings ultimately used to elucidate and mitigate complications. The most significant challenge associated with the development of computational models is in the encapsulation of patient-specific anatomy and surgical planning. The findings of this review provide a basis for future direction in computational modeling of the reverse shoulder.

The most important complications of trapeziometacarpal arthroplasty are dislocation and component loosening. Incorrect cup position is often a contributing factor. Intra-operative guidelines to optimize cup orientation have recently been described. We evaluated the functional and radiological outcome of 50 Maïa® trapeziometacarpal prostheses that were implanted according to these guidelines. The minimum follow-up was 56 months. No constrained cups were used. Functional outcome was good to excellent. No spontaneous dislocations occurred. No radiological signs of loosening were observed. There was one case of premature wear. The survival rate was 96% (95% confidence interval 85 to 99%) at a mean of 65 months, with two prosthesie removed for posttraumatic trapezial fractures. This study shows that correct implant position can lead to reliable medium-term results after trapeziometacarpal joint arthroplasty. Level of evidence: IV

Background: Aseptic component loosening is a leading cause of revision for total ankle replacement. Different operative approaches for resecting the tibia and talus impact the bony support for the prostheses due to variations in both bone density and resection area, and may therefore impact loosening performance. Methods: Computed tomography data from 116 subjects were obtained, and solid models of the talus and tibia were generated. Bone density, resection area, and bony support were measured on a series of flat resections for each subject, at multiple resection depths. Similar measurements were performed using a series of subject-specific, anatomic radius–based resections (“round resections”) at multiple depths. Results were compared to assess the impact of both resection type (flat vs round) and resection depth (6-16 mm for the tibia, 2-6 mm for the talus) on bony support. Results: Statistically significant decreases in bony support for both the talus and the tibia were obtained for flat resections as compared to round resections. A decrease of 8% to 19% for the tibia was seen for all resection depths; a decrease of 8% to 46% for the talus was seen, with greater decreases seen for shallower flat-cut resections. Conclusion: Bony support in total ankle arthroplasty may be decreased using flat resections compared to round resections at comparable resection depths. Estimated differences are resection-level dependent and different for the distal tibia vs the proximal talus. Clinical Relevance: Biomechanical characteristics of total ankle replacement impacted by bony support of the prostheses, including implant stability and resistance to subsidence, may be improved with round resections as compared to flat-cut resections.

Background Patients with destructive acetabular lesions are at high risk for morbidity. Harrington described reinforcing acetabular diseased bone with methylmethacrylate, supplemented by metal fixation, to allow total hip reconstruction. However, all published studies using this technique report dislocations. We believe that initial use of constrained liners would help alleviate dislocation risk, without increasing component loosening or polyethylene wear. Methods Sixty-eight patients who underwent Harrington hip arthroplasties for metastatic cancer from August 2005 to March 2015 were identified. All patients had a constrained acetabular liner implanted during their index procedure. Electronic medical records and radiographs were reviewed. A literature review of studies with similar technique was used as a historical control. Results Forty-seven patients (69.2%) died 22.7 ± 22.7 months after surgery, at age 62.4 ± 17.2 years. At an average clinical follow-up of 9.9 ± 14.2 months (range 2-50 months), we found no incidents of dislocation. No patients had component failure requiring revision or evidence of loosening on x-ray. Thirteen papers, comprising 185 patients, demonstrated 39 patients (21.1%) with dislocations and 13 patients (7.0%) requiring revision surgery for aseptic loosening. Conclusion Modified Harrington technique has demonstrated relative durability when reconstructing metastatic acetabular disease, although dislocation occurs in approximately 20% of patients. This study demonstrates that initial use of a constrained liner can alleviate postoperative dislocations without increasing risk of perioperative complications. Even modest reduction in complications during the limited lifespan of oncologic patients can have dramatic positive effects on quality of life.

Rates of total knee arthroplasty (TKA) in younger patients are rising significantly. A recent study performed at our institute illustrated the excellent survivorship of TKAs in patients younger than 55 years at a mean follow-up period of 25 years. This study reports on the 25 knees in this series that required revision surgery. Twenty-five revisions were performed in 24 patients. Indication for revision, clinical outcomes, and radiographs were reviewed at their most recent follow-up. Revisions were performed in 5 cases of infection, 2 cases of fracture/trauma, 17 cases of wear/loosening, and 1 case of instability. The average duration from primary TKA to revision surgery for the 25 knees was 12.5 years (range, 2–26 years). Follow-up was obtained in 24 of 25 TKAs. Nine of the 24 patients (10 knees) had died at the time of follow-up. The average duration from revision surgery to follow-up examination for the remaining knees was 10.5 years. Using the Knee Society scoring system, the average knee score was 89.0 points and the average functional score was 75.6 points. The mean Tegner activity score was 4.6 which exceeded the mean score for unrevised TKAs (2.9). The average range of motion was 119 degrees. None of the knee radiographs showed evidence of component loosening. Young patients who undergo TKA that require revision surgery had good mid-term clinical outcomes. This information is important in completing the clinical picture and outcomes associated with young patients undergoing TKA.

In 2006, we reviewed articles published between 1996 and 2005 pertaining to anatomic total shoulder arthroplasty (TSA); that analysis revealed 414 complication events after 2,810 total shoulder replacements (a rate of 14.7%)[1][1]. Component loosening accounted for 161 (39%) of the 414 complications

Introduction Walch type B2 has biconcave glenoid with posterior erosion, bone loss and humeral head subluxation. This leads to decreased glenohumeral contact area and increased contact pressure. During total shoulder arthroplasty(TSA), uncorrected retroversion causes eccentric loading and failure of glenoid component. It also leads to humeral head decentring with posterior rim loading, early glenoid wear and component loosening. This study aims to review anatomical restoration of glenoid version and humeral head centring in TSA with B2 glenoid using CT scans. Methods This is a retrospective review of TSA for glenohumeral osteoarthritis with B2 Glenoid morphology. All polyethylene posterior wedge augmented glenoid component was used. All patients underwent pre and post surgery CT Scans. Glenoid version was calculated using neoglenoid line and medial scapular border as reference point. Post-operative humeral head centering was calculated using offset of centre of rotation of humeral head with plane of scapula on axial CT-Scan. Results Study had 10 patients with 11 TSA between June 2017 and July 2018. Mean age was 59(45–80)years. Mean preoperative retroversion was 16(13–23)degrees. This was corrected to a mean of 0° retroversion postoperatively. 63% had good radiological correction (0–5° retroversion). Humeral head was well centered post-operatively with mean humeral scapula alignment offset of 2.1(0.8–4.5) mm posteriorly. All cases had well-centered humeral head postoperatively with offset less than 5 mm. Conclusions Total shoulder replacement in B2 glenoid is technically demanding. Our radiological results show favourable outcome in terms of correction of gelenoid retroversion and eliminating posterior instability using wedge glenoid component. Level of evidence IV.

Total shoulder arthroplasty has gained remarkable popularity in the last few decades. Critical review of outcomes and large registries in different countries have led to newer designs and expanding indications, which have resulted in rapid growth around the world. Despite numerous advances in surgical techniques and implant designs, however, complications still occur, and with an active aging population and increasing popularity among upper extremity surgeons, we can expect those complications to increase both in volume and complexity. Recognition and timely diagnosis of adverse outcomes can help surgeons not only correct and salvage a poor outcome but understanding what leads to common complications may also help us to anticipate and avoid them altogether. Infection, component loosening, periprosthetic fracture, and instability are the major reasons for revision surgery. Though the diagnosis may be difficult, as many signs and symptoms may be subtle and nonspecific, a careful history and physical examination, critical review of radiographs, and a healthy level of suspicion may offer clues and guide the surgeon toward advanced imaging, laboratory studies, and other diagnostic measures. This chapter aims to provide the reader with the tools to successfully identify those patients who may need further surgical treatment in the setting of a total shoulder arthroplasty as well as to help avoid common pitfalls implicated in certain complications.

Implant loosening is a common cause of reoperation after THA. Plain radiographs have been the default modality to evaluate loosening, although radiographs provide a relatively insensitive assessment of integration; cross-sectional modalities may provide a more detailed evaluation but traditionally have suffered from metal-related artifacts. We sought to determine whether MRI is capable of reliably detecting operatively confirmed component loosening in patients after hip arthroplasty.(1) Is assessing implant integration using MRI (with multiacquisition variable resonance image combination, [MAVRIC]) repeatable between readers? (2) What is the sensitivity and specificity of MRI with MAVRIC to evaluate component loosening, using intraoperative assessment as a gold standard? (3) How does the sensitivity and specificity of MRI with MAVRIC for surgically confirmed component loosening compare with those of radiographs?Between 2012 and 2017, 2582 THAs underwent revision at one institution. Of those, 219 had a preoperative MRI with MAVRIC. During that period, the most common indication for obtaining an MRI was evaluation of potential adverse local tissue reaction. The surgeons' decision to proceed with revision was based on their overall assessment of clinical, imaging, and laboratory findings, with MRI findings cited as contributing to the decision to revise commonly occurring in the setting of recalled implants. Of the THAs that underwent MRI, 212 were included in this study, while seven were excluded due to equivocal operative notes (5) and excessively poor quality MRI (2). MRI was performed at 1.5T using a standardized arthroplasty imaging protocol, including MARS (metal artifact reduction sequencing) and MAVRIC techniques. Two independent musculoskeletal fellowship-trained readers (one with 26 and one with 5 years of experience) blinded to operative findings scored a subset of 57 hips for implant integration based on Gruen zone and component loosening (defined as complete circumferential loss of integration around a component) to evaluate interobserver reliability. A third investigator blinded to imaging findings reviewed operative notes for details on the surgeon's assessment of intraoperative loosening.Gwet's agreement coefficients (AC) were used to describe interobserver agreement; these are similar to Cohen's kappa but are more resistant to certain paradoxes, such as unexpectedly low values in the setting of very high or low trait prevalence, or good agreement between readers on marginal counts. Almost perfect interobserver agreement (AC2 = 0.81-1.0) was demonstrated for all acetabular zones and all femoral Gruen zones on MRI, while perfect (AC1 = 1.0) agreement was demonstrated for the overall assessment of acetabular component loosening and near perfect agreement was shown for the assessment of femoral component loosening (AC1 = 0.98). MRI demonstrated a sensitivity and specificity of 83% (95% CI, 65-96) and 98% (95% CI, 97-100), respectively, for acetabular component loosening and 75% (95% CI, 55-94) and 100% (95% CI, 100-100), respectively, for femoral component loosening. Radiographs demonstrated a sensitivity and specificity of 26% (95% CI, 12-47) and 100% (95% CI, 96-100), respectively, for acetabular component loosening and 20% (95% CI, 9-47) and 100% (95% CI, 100-100), respectively, for femoral component loosening.MRI may provide a repeatable assessment of implant integration and demonstrated greater sensitivity than radiographs for surgically confirmed implant loosening in patients undergoing revision THA at a single institution. Additional multi-institutional studies may provide more insight into the generalizability of these findings.Level III, diagnostic study.

BACKGROUND: Implant loosening is a common cause of reoperation after THA. Plain radiographs have been the default modality to evaluate loosening, although radiographs provide a relatively insensitive assessment of integration; cross-sectional modalities may provide a more detailed evaluation but traditionally have suffered from metal-related artifacts. We sought to determine whether MRI is capable of reliably detecting operatively confirmed component loosening in patients after hip arthroplasty. QUESTIONS/PURPOSES: (1) Is assessing implant integration using MRI (with multiacquisition variable resonance image combination, [MAVRIC]) repeatable between readers? (2) What is the sensitivity and specificity of MRI with MAVRIC to evaluate component loosening, using intraoperative assessment as a gold standard? (3) How does the sensitivity and specificity of MRI with MAVRIC for surgically confirmed component loosening compare with those of radiographs? METHODS: Between 2012 and 2017, 2582 THAs underwent revision at one institution. Of those, 219 had a preoperative MRI with MAVRIC. During that period, the most common indication for obtaining an MRI was evaluation of potential adverse local tissue reaction. The surgeons’ decision to proceed with revision was based on their overall assessment of clinical, imaging, and laboratory findings, with MRI findings cited as contributing to the decision to revise commonly occurring in the setting of recalled implants. Of the THAs that underwent MRI, 212 were included in this study, while seven were excluded due to equivocal operative notes (5) and excessively poor quality MRI (2). MRI was performed at 1.5T using a standardized arthroplasty imaging protocol, including MARS (metal artifact reduction sequencing) and MAVRIC techniques. Two independent musculoskeletal fellowship-trained readers (one with 26 and one with 5 years of experience) blinded to operative findings scored a subset of 57 hips for implant integration based on Gruen zone and component loosening (defined as complete circumferential loss of integration around a component) to evaluate interobserver reliability. A third investigator blinded to imaging findings reviewed operative notes for details on the surgeon’s assessment of intraoperative loosening. RESULTS: Gwet’s agreement coefficients (AC) were used to describe interobserver agreement; these are similar to Cohen’s kappa but are more resistant to certain paradoxes, such as unexpectedly low values in the setting of very high or low trait prevalence, or good agreement between readers on marginal counts. Almost perfect interobserver agreement (AC(2) = 0.81–1.0) was demonstrated for all acetabular zones and all femoral Gruen zones on MRI, while perfect (AC(1) = 1.0) agreement was demonstrated for the overall assessment of acetabular component loosening and near perfect agreement was shown for the assessment of femoral component loosening (AC(1) = 0.98). MRI demonstrated a sensitivity and specificity of 83% (95% CI, 65–96) and 98% (95% CI, 97–100), respectively, for acetabular component loosening and 75% (95% CI, 55–94) and 100% (95% CI, 100–100), respectively, for femoral component loosening. Radiographs demonstrated a sensitivity and specificity of 26% (95% CI, 12–47) and 100% (95% CI, 96–100), respectively, for acetabular component loosening and 20% (95% CI, 9–47) and 100% (95% CI, 100–100), respectively, for femoral component loosening. CONCLUSION: MRI may provide a repeatable assessment of implant integration and demonstrated greater sensitivity than radiographs for surgically confirmed implant loosening in patients undergoing revision THA at a single institution. Additional multi-institutional studies may provide more insight into the generalizability of these findings. LEVEL OF EVIDENCE: Level III, diagnostic study.

Background The purpose of this study was to compare preoperative radiographic evaluation with intraoperative video and explant analysis in patients undergoing revision of a previous anatomic total shoulder arthroplasty (TSA). Methods We evaluated the preoperative radiographs of 165 revisions of failed TSAs for component loosening and glenohumeral registry (ie, the spatial relationship of the glenoid component and the prosthetic humeral head). Seventy-nine intraoperative videos were evaluated for component stability, rotator cuff (RC) integrity, synovitis, and glenoid bone loss. Eighty-seven explants were reviewed to assess wear patterns and presence of backside cement. Results Of 79 glenoid components, 47 were radiographically loose, but only 30 of 79 were loose intraoperatively. Thirty-two were radiographically fixed, but only 26 of 32 were fixed intraoperatively. If radiographically loose, 53% had severe glenoid bone loss. If radiographically fixed, 77% had mild to moderate bone loss (P = .008). Synovitis was associated with glenoid fixation: mild with a loose glenoid (6%) and severe with a fixed glenoid (30%, P = .012). Superior registry comprised 46%. RC deficiency was associated with posterior and anterior registry (88% and 79%, respectively). Explant examination revealed an eccentric wear pattern was predominant. Conclusion Radiographic evaluation of glenoid loosening in patients undergoing revision of TSAs will often differ from intraoperative findings (40% false-positive rate and 17% false-negative rate). Assessment of glenohumeral registry can help anticipate RC deficiency, with posterior and anterior registry associated with RC deficiency. Patients with a loose glenoid are more likely to have severe synovitis and more severe glenoid bone deficiencies. Failed TSAs are more likely to have asymmetrical wear of the glenoid component, suggesting altered pathomechanics that may have led to failure.

Background The biconcave (B2) glenoid is characterized by preservation of the anterior portion of the native glenoid with asymmetric wear of the posterior glenoid. Surgical options for glenoid correction have evolved. The goal of shoulder arthroplasty is to place the implants in such a manner to return the humeral head to a centered position and restore the joint line to a neutral position. There is no current consensus on method of treatment and correction. Methods The current and historical literature on total shoulder arthroplasty was used to examine technique viability. Results Asymmetric remaining can be used to address up to 15° of version correction without compromise of cortical bone. It is important to have the proper presurgical planning, to understand the limitations of correction, and to have other options available to treat the biconcave glenoid.