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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.

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 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.

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.

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.

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.

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.

Background The results of ceramic-on-ceramic (CoC) total hip arthroplasty (THA) in younger patients were not univocal. This study aims to evaluate the results of CoC bearing THA in patients younger than 50 years. Methods A total of 90 younger patients performed CoC THAs during March 2003 and May 2008 were included in this study. Hip function and activity were evaluated with Harris hip score and University of California Los Angeles activity score. We had discussed survival rates, radiological findings of component loosening or osteolysis, and ceramic-related complications in these patients. Results The mean Harris hip score increased from 46.3 ± 12.0 points (range, 28-70 points) before surgery to 92.5 ± 5.6 points (range, 78-100 points) at the final follow-up. The mean preoperative University of California Los Angeles activity score was 4.2 ± 1.1 points (range, 2-6 points), which improved to a mean of 7.2 ± 1.3 points (range, 4-10 points). At the time of the last follow-up, there was found to be 1 occurrence of hip dislocation, 1 squeaking, and 2 "sandwich" ceramic liners fractured during normal activity of daily living. No hips showed osteolysis or required revision for aseptic loosening. Kaplan-Meier survivorship with revision due to loosening or osteolysis was 100% and with revision due to ceramic fracture was 97.3% (95% confidence interval, 93.7%-100%) at a mean of 9.4 years. Conclusions This study with the use of CoC bearings THAs in younger patients have shown promising results and higher rate of survivorship without evidence of osteolysis.

Revision total shoulder arthroplasty is performed for a variety of patient symptoms, including shoulder pain, instability, or stiffness. The technical reasons found for revision include component loosening or malposition. Removing the humeral stem during revision can increase morbidity and blood loss during a procedure. The ability to use a universal stem that can be utilized in both anatomic and reverse shoulder arthroplasty can be beneficial in three main areas. For revision surgeries, cost is much less, OR time is decreased, and complications are much less frequent.

Arthroscopy may be used to diagnose symptomatic glenoid loosening following anatomic total shoulder arthroplasty (aTSA), and arthroscopic glenoid component removal may suffice as treatment for some patients. Arthroscopy may be used to diagnose shoulder prosthetic joint infection (PJI) following aTSA and reverse shoulder arthroplasty (RSA). Tissues are biopsied from multiple sites within the joint and the subdeltoid or subacromial space, and they are cultured for a minimum of 14 days. Postoperative adhesions arising after prosthetic shoulder arthroplasty (PSA) may be released arthroscopically. However, other problems contributing to shoulder stiffness such as component malpositioning or shoulder PJI require additional intervention. Arthroscopy may be used to repair select rotator cuff tears that arise acutely following aTSA, but chronic attritional tears do not heal after repair; therefore, revision to RSA often is needed. Many complications following PSA, such as infection, fixed instability, humeral component loosening, and major humeral or glenoid bone loss, are not adequately treated using arthroscopic techniques. However, arthroscopy following PSA may help to diagnose and treat other complications, even as the precise indications following aTSA and RSA remain unclear.

Background: In the 1970s and 1980s, hip resurfacing was largely unsuccessful, due to impingement, wear, and component loosening. Today, the availability of better technique and highly cross-linked polyethylene avoids the early causes of failure and provides a successful solution to younger, active patients with advanced osteoarthritis. Methods: The author reviewed the results of 2,154 hip resurfacing arthroplasties he performed over a 21- year period. The procedures used a cementless titanium metal-backed acetabular implant and highly cross- linked polyethylene liner. Results: At a mean follow-up period of 9.5 years (range, 5–21 years), the Kaplan-Meier survivorship was 97.5%, the mean Harris Hip Score was 97, and the UCLA activity score was 8. There were 32 deaths unrelated to the procedure and 35 patients were lost to follow-up. Complications leading to revision included femoral loosening (n=9), infection (n=3), femoral neck fracture (n=12), and these were revised successfully to total hip replacement. Another five patients underwent revision resurfacing for acetabular loosening. There was no evidence of wear through of the polyethylene and examination of retrieved polyethylene components showed a low wear rate from 0.003 to 0.07 mm per year. Conclusions: Hip resurfacing today has proven to be a successful procedure with results as good as or better survivorship than total hip replacement and better function. It is a reliable procedure that meets the physical demands of younger, active patients.

Component malpositioning during Birmingham hip resurfacing increases the risk for component wear, metallosis, component loosening, and the likelihood of dislocation and revision surgery. Computer-assisted navigation can increase the accuracy to which components are placed, and the utilization of this technology in Birmingham hip resurfacing is increasing. The present report summarizes the accuracy of acetabular component positioning in a Birmingham hip resurfacing case utilizing navigation. Intraoperative C-arm fluoroscopy following the use of the navigation tool confirmed excellent seating, positioning, and stability of the acetabular component. In addition, post-operative antero-posterior radiographs confirmed device accuracy and revealed a stable joint with no evidence of acetabular loosening or femoral fracture. Computer-assisted navigation may therefore be an effective tool to improve the accuracy of component positioning during Birmingham hip resurfacing.

Severe tibial bone loss is one of the most challenging aspects in revision total knee arthroplasty (TKA). Bone loss can be the result of (1) aseptic failure with component loosening, subsidence, osteolysis, and fracture, (2) septic failure with bone resorption and osteolysis, and (3) iatrogenic bone loss following component removal. Accurate assessment of the severity of the tibial bone loss is necessary, especially in the proximal metaphysis, since it impacts tibial component position and fixation. Despite several classification systems, the radiographic evaluation of the bone defects is often difficult and underestimated [1]. The final determination of tibial bone loss is made at the time of surgery. The most useful classification system is the Anderson Orthopaedic Research Institute (AORI) classification that describes the severity of the tibial bone loss based upon the integrity of the metaphysis and whether one or both plateaus are involved [2].

Background This study assessed the accuracy of computed tomography (CT) arthrography when evaluating glenoid component stability in the setting of postarthroplasty shoulder pain. Methods We retrospectively reviewed all patients presenting to the clinic during a 5.5-year period to identify those with a painful shoulder arthroplasty more than 1 year after the index procedure. We excluded reverse and hemiarthroplasty procedures, patients with a clearly identifiable cause for pain, such as rotator cuff insufficiency or gross component loosening as seen on plain radiographs, and those with culture-positive aspiration. There were 14 patients with suspected glenoid component loosening but inconclusive plain radiographs. Each of the 14 patients underwent a CT arthrogram that was evaluated by the senior author (J.J.P.W.) for the presence or absence of contrast material underneath the polyethylene component. Operative reports and surgical videos from subsequent arthroscopy were reviewed to assess glenoid component stability as determined by direct arthroscopic visualization. Results CT arthrography suggested glenoid component loosening in 8 of 14 patients (57.1%), and arthroscopic inspection identified loosening in 10 of 14 patients (71.4%). In 3 of 10 patients (30%), CTA suggested a well-fixed glenoid component, but gross loosening was identified during arthroscopy. In this study, CTA yielded a sensitivity of 70%, a specificity of 75%, a positive predictive value of 87.5%, and a negative predictive value of 50.0%. Conclusion CTA had a low negative predictive value (50%), and therefore, the prediction of component stability based on the absence of contrast between the glenoid component and the bone-cement interface does not always reflect true stability.

Background Many shoulder arthroplasties revised for pain, stiffness, or component loosening are culture positive for Propionibacterium . The culture results are unknown until days or weeks after surgery, too late to inform intraoperative surgical decisions and immediate postsurgical antibiotic treatment. The objective of this study was to identify preoperative and intraoperative characteristics that may alert surgeons to an increased likelihood of positive cultures. Methods We analyzed the records of 132 shoulders that underwent surgical revision of a shoulder arthroplasty, 66 of which became culture positive for Propionibacterium and 66 did not. Results Propionibacterium -positive and Propionibacterium- negative shoulders were similar with respect to many characteristics; however, Propionibacterium- negative shoulders were revised sooner after the index procedure and were significantly more likely to be female, to have sustained a fall, to have instability, and to have rotator cuff deficiency. Intraoperatively, Propionibacterium- positive shoulders demonstrated more glenoid erosions, glenoid osteolysis, glenoid loosening, and a higher incidence of a soft tissue membrane between the humeral component and humeral endosteum. Shoulders culture positive for Propionibacterium were more likely to be culture positive for another bacteria. Conclusions Although Propionibacterium- positive and Propionibacterium- negative shoulders have many similarities, factors such as male gender, delayed presentation, glenoid osteolysis and loosening, humeral membrane, and the absence of instability or cuff failure should arouse suspicion of Propionibacterium and suggest the need for deep cultures and consideration of aggressive surgical and medical treatment.

Conversion of hip hemiarthroplasty to total hip arthroplasty (CTHA) is a complication-prone procedure with high dislocation rates and early component loosening. The purpose of this study was to evaluate the complications of CTHA performed using contemporary implants. Forty-six patients who had CTHA were retrospectively matched to a control group of 46 patients who had a first-time THA revision. The mean follow-up was 47 (range 6–149) and 23 (range 6–139) months for CTHA and control groups, respectively. Radiographs taken at the last follow-up visit were evaluated for signs of loosening or other modes of failure. Clinical outcome was evaluated with the Harris Hip Score (HHS). Complications occurred in five patients (10.9 %) in the CTHA group, and all required repeat revision. Two patients (4.3 %) were revised due to recurrent dislocation. The other re-revisions were done for acetabular or femoral component loosening and deep infection. In the control group, complications occurred in six patients (13.0 %), and three (6.5 %) were revised with a constrained liner due to recurrent dislocations. Dislocation rates and re-revision for CTHA were not significantly different than those of first-time THA revision when using contemporary revision implants.

Introduction Acetabular component loosening is a leading cause for revision after metal-on-metal hip resurfacing arthroplasty (MMHRA). We aimed to identify potential risk factors and determine radiographic signs associated with this mode of failure. Methods From a series of 1375 hips treated with MMHRA, 21 (20 patients) underwent revision surgery secondary to aseptic loosening of the acetabular component and 6 patients had a radiographically loose acetabular component. A control group of 27 hips (26 patients) was selected among the patients that did not have a revision, and was matched for age, gender, component size and diagnosis. Results Mean time to revision in the loosening group was 103.0 months and the mean time of follow-up in the control group was 161.4 months. We found greater activity levels, range of motion scores, and cup abduction angles in the loosening group. The centre-edge (CE) angle of Wiberg was 10° lower in the loosening group compared with the control group. In addition, 11 of the hips from the study group presented a sclerotic halo superior to the cup on the last radiograph vs. none in the control group. There was no difference in the prevalence of postoperative reaming gaps or radiographic signs of neck-cup impingement between the 2 groups. Discussion Risk factors for acetabular loosening included hip dysplasia with low CE angle, and a large cup abduction angle. The patient's level of activity influences the appearance of symptoms and the time to revision. We recommend selecting patients with a sufficient CE angle and properly orienting the cup.

Surface replacement of the hip was established in the 1970s as a bone preserving alternative to total hip replacement. However, problems with femoral neck fracture, osteolysis, and component loosening led to early failures and an abandonment of the procedure. The modern hip resurfacing has improved upon past results with new implant designs and materials. The benefits include the preservation of bone, lower dislocation rate, and more physiologic bone loading, factors which may lead to an ability for a higher activity level. National joint registry results find that a certain group of patients has greater survivorship with resurfacing than with total hip replacement. Therefore, we believe that surface replacement arthroplasty is a viable alternative in this subgroup of patients.

The outcomes of total shoulder arthroplasty (TSA) for painful arthritis of the glenohumeral joint are excellent with significant improvement in pain and function. Increased use of total shoulder arthroplasty over the past decade has led to identification of common complications. Although the complication rate is low, accurate and timely diagnosis, appropriate management, and implementation of methods for prevention are critical to a successful long-term outcome. The most common complications include infection, glenoid and humeral component loosening, rotator cuff tear, periprosthetic fracture, and neurologic injury. The purpose of this review is to outline the best practices for diagnosing, managing, and preventing these complications.

Background Pigmented villonodular synovitis (PVNS) is a rare, benign, painful proliferation of the synovium previously treated successfully with total hip arthroplasty (THA). Published results come from small series; therefore, the purpose of this study is to investigate the outcomes of THA in the setting of PVNS. Methods We identified 25 patients with histologically confirmed, diffuse PVNS who underwent THA between 1971 and 2013. Mean follow-up and age was 10 years and 39 years. Before arthroplasty, 16 patients (64%) had at least 1 surgical procedure (mean, 1; range, 1-3) to treat PVNS. Twenty (80%) patients had “active” disease and underwent synovectomy. No constrained acetabular components were used. Results The 10-year disease free-survival was 100%. Recurrence occurred in 1 patient at 24 years postoperatively. Nineteen patients (76%) sustained a complication (most commonly component loosening (n = 12 [48%]), and 16 required revision surgery. The 10-year revision-free survival was 66% for conventional polyethylene implants and 100% for highly cross-linked polyethylene devices. Mean Harris Hip Score improved significantly from 48 (range, 23-69) preoperatively to 78 (range, 47-96) postoperatively (P Conclusion THA in the setting of PVNS improves patient function with a low rate of local recurrence. Complication and revision rates are high in this series likely owing to the young and active patient population and the use of conventional polyethylene. Modern bearings theoretically reduce the risk of revision.

BACKGROUND The aim of this paper is to present the results of hip joint arthroplasty with the use of the Taperloc stem. MATERIAL AND METHODS The study group consisted of 117 patients (75 women and 42 men) who underwent 121 hip joint arthroplasties with Taperloc stems. Mean age of the patients at surgery was 53.8 years (range: 2475 years). Mean follow-up period was 159.5 months. RESULTS Pre-operative Merle d'Aubigne-Postel scores (modified by Charnley) of the study group were poor in all patients. Mean post-operative improvement was 6.6 points. Excellent results were obtained in 86 cases, good in 19, fair in 9 and poor in 7 cases. Poor results were always associated with implant component loosening: 5 cases of acetabular cup loosening, 1 case of a loosened stem and 1 septic loosening of the entire endoprosthesis. In six cases (4.9%), patients developed heterotopic ossification. According to the Kaplan-Meier estimator, 10 years' survival probability was 94.21% for the whole endoprosthesis and 98.34% for the stem alone. CONCLUSIONS 1. Our follow-up data covering a mean period of over 13 years showed that the use of the Ta-perloc stem substantially reduces hip pain and results in a good lasting clinical outcome. 2. With good surgical technique and in the absence of complications, the risk of aseptic loosening is minimal.

Osteolysis and aseptic component loosening have been recognized as common mechanisms for late total hip arthroplasty failure. Particulate wear debris from the arthroplasty-bearing surface initiates a process of macrophage-induced, osteoclast-mediated bone resorption around implants. Radiographic patterns of osteolysis differ around cemented and cementless implants based on the patterns of particle access through the effective joint space, and influence the approaches taken during revision surgery. Revision surgery will address the failed bearing surface to decrease the generation of particular debris. The approach to component revision surgery is based on osteolysis lesion size, arthroplasty component stability, locking mechanism integrity, structural bone availability for biologic fixation of revised components, and patient’s health status. This chapter reviews the current knowledge of osteolysis and presents approaches for both conservative and surgical treatment.

Radiolucent lines in total shoulder arthroplasty around the glenoid component are not uncommon in post-operative x-rays and the incidence varies. A certain percentage progress and as the lines enlarge can lead to component loosening. One study reported a 9% incidence at 2 years and 27% incidence at 5 years. A recent long term study (15 to 20 years) reported a 73% incidence. Radiolucent lines can be caused by anatomy (posterior glenoid wear) or pathology (inflammatory arthritis) as well as technical factors such as glenoid implant design (metal back) and improper implantation techniques where the prosthesis is not fully seated or cement is used to fill a defect. Every attempt should be made to avoid lucent lines. Minimal bone should be removed from the glenoid vault and a pressure injection type of insertion is helpful in getting the cement into the cancellous bone. Furthermore a peg type of glenoid implant rather than a keel type is preferred as this has been associated with a lower incidence of radiolucent lines.

Background Glenoid bone grafting can be useful to restore an asymmetrically eroded glenoid to better support the glenoid component and improve positioning. The purpose of this study was to evaluate the clinical and radiographic results of patients undergoing structural bone grafting for glenoid deficiency with placement of a cemented glenoid component during primary total shoulder arthroplasty. Methods Between January 1, 1976, and December 31, 2008, 24 patients (25 shoulders) of 2607 shoulders undergoing primary total shoulder arthroplasty (0.96%) had structural bone grafting with a humeral head autograft and screw fixation. The mean clinical follow-up was 8.7 years, and the mean radiographic follow-up was 7.6 years. Results Twenty-three shoulders experienced pain relief, and patients expressed satisfaction with the operation in these shoulders. Postoperative active elevation averaged 148°, and external rotation with the arm at the side averaged 60°. On radiographic evaluation, 10 shoulders had glenoids at risk for component loosening. Two of these shoulders were symptomatic and underwent revision surgery to address glenoid component loosening. The Neer result rating was excellent in 18 shoulders, satisfactory in 5, and unsatisfactory in the 2 shoulders undergoing revision. Conclusion Structural bone grafting in primary total shoulder arthroplasty is uncommonly necessary. When it is performed, the clinical outcomes are favorable; however, radiographic analysis shows a moderate rate of failure of glenoid component fixation. It seems likely that alternative treatment methods may prove to be more effective in addressing glenoid wear.

We evaluated 106 knees that underwent primary total knee arthroplasty (TKA) with the navigation-assisted gap balancing technique using an e.-motion cruciate retaining floating platform (FP) mobile-bearing prosthesis to prospectively assess the survival of the e.-motion FP system after a minimum follow-up of 4 years. There was no evidence of any complications, including dissociation or breakage of the polyethylene liner or component loosening at last follow up (5.1 ± 0.6 years). Four knees, however, required re-operation, three for distal femoral fracture, and one for infection. The estimated 5-year prosthesis survival rates without revision for any reason and for prosthesis-associated problems were 96.2% and 100%, respectively. The e.-motion floating platform, with a cruciate retaining design under navigation guidance, demonstrated excellent clinical results and 5-year survival rate.

Shoulder arthroplasty is regularly performed in patients with arthritis degeneration to regain their own shoulder functions. Arthritis shoulder often link to glenoid deformation, especially posterior wear resulting in glenoid retroversion. To reconstruct severely retroverted glenoid, placing glenoid prosthesis has been performed. The use of cementless glenoid prosthesis with porous surface has been introduced to shoulder arthroplasty since this enhances bone ingrowth and maximizes fixation. However, research in the success of cementless glenoid prosthesis following arthroplasty in retroverted glenoid has been rarely reported. In this study, we aimed to investigate two different approaches of using cementless glenoid prosthesis, standard and wedged component designs. Finite element method was conducted to compare micromotions obtained from the two approaches. The results showed that the wedged component seemed to be an appropriate approach for reconstructing retroverted glenoid due to the small micromotions obtained. Therefore, the use of wedged prosthesis could prevent component loosening and enhance the success of cementless shoulders arthroplasty.

Total shoulder arthroplasty (TSA) in cases with posterior wear can be addressed by eccentric reaming of the anterior glenoid or by augmenting the posterior glenoid with bone grafting or augmented glenoid implants. We report the results of TSA with posterior glenoid bone grafting (PGBG) with humeral head autograft in patients with shoulder osteoarthritis and severe posterior glenoid wear.A retrospective review of cases from 2004 to 2014 revealed 34 patients. Preoperative and postoperative radiographs were evaluated for glenoid version and humeral head subluxation as well as component loosening. Patient-reported outcomes were compared preoperatively and postoperatively. Complications and reoperations were also evaluated.Of the 34 patients, 28 (82.4%) were available at a minimum of 2 years' follow-up. PGBG corrected glenoid retroversion from -28° ± 4° preoperatively to -4° ± 2° (P .001). Humeral head subluxation also improved after PGBG with respect to the scapular axis and to the midglenoid face (P .001). Radiographic analysis revealed all PGBGs had incorporated. Radiographically, 3 patients (10.7%) had a total of 5 broken or displaced screws. In addition, 3 patients (10.7%) had a broken metal marker in the center peg of the glenoid component. No patients required component revision surgery by final follow-up. Only 1 reoperation occurred for capsular release. Patients showed significant improvements in all patient-reported outcomes.Patients undergoing primary TSA with humeral head autograft PGBG showed significant improvements in glenoid version, humeral head subluxation, patient-reported outcomes, and range of motion at an average of 4 years' follow-up. There was a low revision rate and a high rate of graft incorporation.

Constrained implants are frequently required in revision total knee arthroplasty (TKA) and are associated with an increase in aseptic component loosening and damage or wear to the constraining mechanisms, compared with primary TKA. The purpose of the following study was to evaluate the midterm clinical and radiographic results including the incidence of bearing complications in a group of patients undergoing revision TKA using mobile-bearing revision TKA implants.We retrospectively reviewed 316 consecutive mobile-bearing revision TKAs performed at 2 centers between 2006 and 2010. There were 183 women and 133 men with a mean age of 66 years. The patients were evaluated clinically using the Knee Society scores. A radiographic analysis was performed. Bearing specific complications (ie, instability or dislocation) were recorded.Patients were followed-up for a minimum of 24 months and a median of 59.88 months (range 24-121.2). The average Knee Society knee score and function scores increased from 40.8 and 47.9 points preoperatively to 80 points and 70.3 points, respectively (P.01). The average knee flexion improved from 105.6° preoperatively to 117.4° postoperatively (P.01). Eight patients required subsequent implant revision. No cases of bearing complications were observed.Revision TKA using mobile-bearing revision components demonstrated favorable midterm clinical and radiographic results with no occurrence of bearing instability or dislocation. Longer follow-up is required to evaluate for potential advantages of mobile-bearings over fixed-bearing revision components in terms of polyethylene wear reduction, reduced stress transmission across fixation interfaces, and reduced stress on the polyethylene post.

Background There is interest in uncemented total knee arthroplasty due to the hope for long-term biologic fixation, but limited data are available regarding uncemented tantalum patellar components. The purpose of this study was to evaluate the radiographic outcomes of uncemented tantalum patellar implants at midterm follow-up. Methods We retrospectively reviewed a consecutive series of 30 knees in 29 patients who underwent cementless total knee arthroplasty with an uncemented metal-backed tantalum patella between September 2006 and April 2009. Patients were required to have a minimum radiographic follow-up of 2 years. Anteroposterior and lateral radiographs of the knee were evaluated for signs of implant fracture or gross loosening. Clinical follow-up was obtained by reviewing each patient's most recent orthopedic record. Results Thirty knees in 29 patients met inclusion criteria. The mean age of the cohort was 59.1 years with a mean body mass index of 31.9 kg/m 2 . Mean postoperative radiographic follow-up time was 5.5 years. Six fractures of the patellar component were noted. This represented a fracture rate of 20% among the entire cohort and 35% among the 17 knees with visible patellae on anteroposterior radiograph. All fractures had a transverse pattern. No gross patellar component loosening was noted. Among patients with component fractures, 2 required revisions for instability and 1 revision was for infection. Conclusion Our results suggest a minimum 20% rate of component fracture at midterm follow-up. Although many of these patellar component fractures were asymptomatic, they have the potential to impact revision rates in the longer term.

To avoid inadvertent vertical positioning of the acetabular component during total hip arthroplasty (THA), the authors routinely “cheat” component abduction an additional 10° horizontal (goal=30°). This likely increases the incidence of components placed into abduction of less than 30°, the clinical consequences of which are not well studied. The purpose of this study was to determine the clinical and radiographic outcomes in patients undergoing THA with acetabular components positioned in less than 30° of abduction as compared with those with components positioned between 30° and 50°. A retrospective review was performed of consecutive patients undergoing primary THA with horizontally cheated acetabular component position performed by a single surgeon. Patients were grouped into cohorts with either component abduction less than 30° or between 30° and 50°. Demographic data, operative data, and complications were recorded. Harris Hip Scores (HHS) and radiographic analysis were obtained from preoperative and most recent clinic visits. Between September 2004 and September 2010, 320 consecutive THA procedures were performed. A total of 149 hips had component abduction less than 30° (mean, 25.8°; range, 15.7°–29.4°). No components had greater than 50° of abduction. At an average 37-month follow-up, no significant difference in HHS was found between the 2 cohorts ( P =.137). The horizontal cohort had no dislocations, component loosening, or osteolysis. By cheating the acetabular component more horizontal, an excessively vertical position was avoided. Component abduction less than 30° yielded equivalent clinical outcomes to component abduction between 30° and 50°. [ Orthopedics. 2016; 39(6):e1092–e1096.]

If it be accepted that tissue reaction to UHMWPE particles is the cause of “osteolysis” and component loosening, then it would seem logical to imply that neither improvement in component design nor their fixation would have an effect on the incidence of component loosening.

Position of the stem within the medullary canal in cemented total hip arthroplasties (THA) has been under scrutiny for some time. Initially this was in the context of stem fracture [1] then in relation to the predictability of the long-term outcome of stem fixation [2]. In both these publications only the antero-posterior (AP) radiographs were examined. More recently the attention has been focused on the high incidence of early failures [3] and suggestions made that endosteal cavitation and component loosening may be due to the direct effect of the ultra high molecular weight polyethylene (UHMWPE) wear particles gaining access to the bone cement interface through cement defects. As a result the trend in the design, instrumentation and the surgical technique has been to facilitate central placement of the stem within the medullary canal avoiding stem tip-cortex contact and aiming at a cement mantle of a predetermined thickness. To what extent does the position of the stem within the medullary canal in cemented THA play a part in the long-term outcome has not been established with certainty. Since a prospective study would not be possible, let alone acceptable, and a long-term follow-up would be necessary, [4] we have attempted to answer the question by examining both failed and successful cases retrospectively.

Background Malposition of the glenoid component can result in premature component loosening or instability. This study was designed to test the ability of an experienced shoulder surgeon to position the glenoid component using standard preoperative planning and surgical bone preparation. Materials and methods Thirteen patients having primary total shoulder arthroplasty were evaluated using 3-dimensional surgical simulator. Ideal version was considered to have version as close to perpendicular to the plane of the scapula, with complete contact of the back side of the component on glenoid bone and maintenance of the center peg of the component within bone. Results The average retroversion angle was 13° (mean, standard deviation [SD] 12°), with a range of 1-42°. In 7 of these 13 cases, preoperative glenoid retroversion was greater or equal to 10°. In 3 cases, the component was malpositioned with greater than 10° of ideal version. In cases with less than 10° of preoperative retroversion, the glenoid component was placed within 10° of ideal version in all cases. Conclusion Traditional methods to correct moderate to severe glenoid deformity and place the glenoid component within 5° of the ideal position are not consistent. Optimal glenoid component placement can be achieved when there is minimal bone deformity. Retroversion greater or equal to 20° makes it difficult to place a pegged glenoid component perpendicular to the plane of the scapula by asymmetric reaming without center peg perforation.

Recent technologic advances in total hip arthroplasty (THA) have focused on improving the longevity and wear characteristics of bearing surfaces that can withstand the high demands of younger and more active patients. Recent reports of early failures of metal-on-metal THA have introduced doubts to its ability to be a viable long-term hard-on-hard bearing surface for hip arthroplasty. Like metal-on-metal, ceramic-on-ceramic (COC) bearing surfaces have excellent in vitro wear characteristics, but there is little information about their long-term track record in vivo, particularly in those patients who are younger and more active. The purpose of this study is to evaluate the long-term outcomes of COC THA in active patients younger than 50 years of age. We retrospectively reviewed 82 consecutive THAs in 64 patients performed by a single surgeon from 1997 to 2000. There were 42 men and 22 women with an average age of 38.6 years. Of the 82 THAs, 39 were performed for avascular necrosis of the hip, 30 for osteoarthritis, 8 for developmental dysplasia, and 5 for inflammatory or posttraumatic arthritis. Clinical outcomes were evaluated using the Harris hip score, and serial radiographs were evaluated for signs of component loosening. The mean follow-up period was 10.1 (range, 10.0-12.3) years. One patient died, and another was lost to follow-up. The mean Harris hip score was 89.8. There were no implants with subsidence or circumferential radiolucent lines. Two patients required revision surgery of their THA for a ceramic liner fracture. One patient complained of squeaking that required revision. There were no cases of revision for ceramic head fracture, instability, or aseptic loosening. At a minimum 10-year follow-up, the survivorship of the COC THA was 96.3%. Modern COC THA in active patients younger than 50 years of age is durable at a minimum 10-year follow-up; however, patients should be advised of the small chance of squeaking and ceramic fracture.

The purpose of this study was to investigate the results of 113 total hip arthroplasties in 109 patients using highly cross-linked polyethylene (HXLPE) after midterm (minimum 7 years) follow-up retrospectively. The mean age at the time of operation was 57 years. Preoperative diagnosis was osteonecrosis in 81 hips and other diagnosis in 32 hips. There was no component loosening. Acetabular osteolysis was found in 12 hips (10.6 %). Mean linear HXLPE wear rate was 0.031 ± 0.012 mm/y. We analyzed the relationship between HXLPE wear rate and several variables influencing HXLPE wear. Only the cup position was related with wear rate of HXLPE significantly (P < .05). The results of total hip arthroplasties using HXLPE showed excellent results with decreased wear rate and low incidence of osteolysis after midterm follow-up.