Radiographic Lucency Research Articles

A Radiographic Evaluation of Uncemented Total Hip Replacements and the Role of Uncemented Implants in the Management of Hip Osteoarthritis in the Elderly Population.

Introduction The idea of an uncemented, fully coated hydroxyapatite (HA) stem was introduced almost 40 years ago, aiming to achieve a solid biological fixation by preserving natural bone activity. While many studies underline the longevity of uncemented total hip replacement (THR), NHS England's Best Practice Tariff (BPT) recommends using cemented implants in patients over the age of 69, with financial penalties when this policy is not met. At the same time, the 'paradox' of increased use of uncemented implants worldwide has been well described, with many surgeons using them regardless of the age group of the patient. Materials and methods This study focuses on the radiographic evaluation of the uncemented Pinnacle/Corail total hip replacement construct in 123 patients of all age groups who underwent an elective procedure, with a minimum radiographic follow-up of two years. Implant information (collared or non-collared stem), femur type (Dorr classification), age, gender, and revision rate were collected and radiographic analysis of the femoral stem and acetabular component was performed for the immediate post-operative, six-month, one- to two-year follow-up radiograph of all patients. We conducted a statistical analysis, dividing the patients into two groups based on age: those above or below 69 years old. Results There was no statistically significant difference in rates of radiographic lucency after two years with regard to the femoral component. Both collared and non-collared stems seem to perform equally well, with no significant difference detected. However, a statistically significant difference in rates of radiographic lucency of the acetabular cup was noted between the two age groups (p=0.018), with higher rates detected in the under-69-year-old age group. Conclusion This study demonstrates that, radiographically, the uncemented Pinnacle/Corail construct performs equally well in all age groups. In our cohort of patients, the age of the patient did not predict the osseointegration of the implant in the short-term follow-up.

Early-to-Intermediate Clinical and Radiographic Outcomes of the Vantage Total Ankle Arthroplasty

Category: Ankle Arthritis Introduction/Purpose: The Vantage total ankle arthroplasty (TAA) features a design based on careful study of arthritic ankles and current ankle biomechanics, with theoretical advantages of a vertically-oriented tibial fixation and a fully congruent talar dome bone-implant interface. In this design-team, single-institution investigation, we report early-to-intermediate term clinical and radiographic outcomes, implant survivorship, and complications of the Vantage TAA. Methods: We retrospectively reviewed prospectively collected data for 278 consecutive patients undergoing Vantage fixed-bearing TAA. Ankles with coronal plane deformity > 25 degrees and suspected poor bone quality were prospectively excluded. Prospectively collected data includes: PROMIS, SF-36, SMFA, VAS and AOFAS hindfoot-ankle scores. Using previously published and commonly accepted evaluation methods, independent radiographic analysis, performed by a non-design surgeon investigator, included pre-operative, 1-year, and most recent follow-up assessments of 2-plane alignment, component position, and the bone- implant interface. A non-design surgeon investigator with dedicated training in statistics performed the statistical analysis using descriptive statistics to report PROM and radiographic measures and Kaplan-Meier survivorship analysis. Results: Mean patient age was 64.8yrs (range:33-86), 44.2% were female, and mean follow-up was 3.1yrs (2.0-5.5). Mean preoperative and postoperative PROMs were as following: PROMIS-Depression 50.3+/-4.2 and 45.6+/-9.8, PROMIS-Physical Function 39.0+/-3.4 and 45.0+/-7.8, SF-36 total score 55.8+/-15.3 and 73.2+/-20.0, SMFA-Function 29.0+/-13.5 and 15.9+/-5.4, VAS 15.8+/-24.8 and 3.1+/-10.1, and AOFAS hindfoot-ankle 46.3+/-16.5 and 81.1+/-16.3 (Table 1). Radiographic lucency at the bone- implant interface was noted in 33 (18.5%) TAAs at final follow-up; 20 (11.2%) were progressive. Lucency was almost exclusive to the tibial component. Implant survivorship was 99.6% [98.9-100.0] at 1-year and 93.3% [88.7-98.2] at the 5-year mark (Table 2, Figure 1). We identified suboptimal bone preparation, initial component alignment and/or component position in all 11 implant failures (Table 3). Conclusion: At early-to-intermediate followup, we observed favorable clinical outcomes, radiographic results and implant survivorship for the fixed-bearing Vantage TAA, especially with optimal bone preparation and component position. Tibial component lucency remains a concern and warrants further investigation. Suboptimal bone preparation, initial component alignment and/or component position was observed in all implant failures.

Subsidence in Centraliser Sign: A Novel Tool to Help Predict Early Subsidence in Periprosthetic Femoral Fractures Around Polished Tapered Stems Treated With Internal Fixation.

Background When treating periprosthetic femoral fractures (PPF) around polished taper slip stems (PTS), determining which patients can be successfully treated with internal fixation can be challenging. We have described the subsidence-in-centraliser (SINC) sign as a radiographic feature of PPF around PTS stems. We hypothesise that a positive SINC sign can help predict a poorer outcome for the fixation of these fractures. Patients and methods Retrospective identification of PPFs around cemented PTS with an appreciable centraliser on radiographs was conducted at a single centre. A positive SINC sign was defined as a post-injury radiograph demonstrating >50% reduction in the radiographic lucency representing the stem centraliser when compared to pre-injury films or complete obliteration of distal lucency when no pre-injury film was available. The primary outcome was the rate of subsequent stem subsidence on follow-up radiographs comparing SINC-positive and SINC-negative fractures, which were managed with open reduction and internal fixation (ORIF). Results Fifty-four patients were included in the analysis. The mean age was 76.8 years, and the mean follow-up for all patients was 12.7 months. Thirty-five fractures were deemed SINC-positive, and 19 were SINC-negative. 17/17 (100%) SINC-positive fractures managed with fixation underwent further subsidence (mean 5.4 mm, SD 2.8). A positive SINC sign demonstrated a sensitivity of 90.5% and specificity of 100% for subsequent stem subsidence in fractures treated without revision. SINC positive fractures underwent significantly more subsidence compared with SINC negative fractures when fixed (5.4 mm vs. 0.28 mm, U = 6.50, p<0.001) at a mean follow-up of 12.7 months. The SINC sign demonstrated strong inter- (k=0.96) and intra-rater (k=0.86) reliability. Conclusion The SINC sign can serve as a useful adjunct in the decision to fix or revise PPF around PTS. A positive SINC sign may represent a cement mantle that cannot be reconstituted anatomically, leading to subsidence after treatment with ORIF.

Cutibacterium positive cultures in total joint arthroplasty: a comparison of the hip, knee, and shoulder.

Cutibacterium spp. (formerly Propionibacterium) is a slow growing, Gram-positive, anaerobic bacteria and is an emerging clinical entity in prosthetic joint infection (PJI). This study compares the presentation, surgical management, and post-operative antibiotic therapy of patients with positive intraoperative cultures during revision total joint arthroplasty (TJA) of the hip, knee, and shoulder. This was a retrospective cohort study of patients from 2014 to 2020 of 57 revision TJAs (27 total hip arthroplasty (THA), 17 total shoulder arthroplasty (TSA), and 13 total knee arthroplasty (TKA)) with intraoperative cultures positive for Cutibacterium at a tertiary academic centre. Patient demographics, pre-operative labs, radiographs, and aspirate results were collected. Intraoperative data was reviewed. Post-operative antibiotic therapy and repeat infections were recorded. Data was compared with univariate analyses. There was no significant difference in pre-operative lab values between the cohorts. All cohorts had >58% radiographic lucency. Revision TSA patients had significantly fewer pre-operative aspirates. Six patients undergoing revision THA, three TKA and one TSA had a repeat infection requiring further surgery. Four in the THA cohort and one in the TKA cohort with repeat infections did not receive prolonged antibiotic therapy. Cutibacterium is an infectious agent that can present in an indolent fashion after TJA. It commonly causes progressive radiographic lucency. The workup and post-operative management differs in the hip, knee, and shoulder, which is likely due to existing literature guiding physician practice. In all joints, Cutibacterium is a virulent pathogen that can cause repeat infections requiring surgical treatment.

Do radiolucencies affect the outcomes of a 4th generation total ankle prosthesis? A 2-year follow-up

Category: Ankle Arthritis; Ankle Introduction/ Purpose: Fourth generation ankle replacements benefit from improved surgical technique, respect for bony preservation, and increased surgeon awareness of operative indications. The rate of radiolucencies around the tibial component observed in studies about 3rd generation total ankle replacements are reported at rates that range from 30% to 43%. To date, studies have not been shown to predict survivorship or patient reported outcomes (PROs) however. We hypothesize that radiolucenices do not affect PROs or survivorship. Methods: Patients presenting for a total ankle replacement at 9 institutions were prospectively enrolled in academic and private settings. Each patient received an INFINTY ankle prosthesis (Stryker, Memphis, TN, USA). Implants were assessed for subsidence and the presence of radiolucencies based on the analysis and comparison of all postoperative weightbearing ankle radiographs available. Subsidence was defined as a change of tibial component alignment greater than 5degrees or a change in the vertical position of the talar component of 5 mm or more. Subsidence and radiolucent lines were deemed nonprogressive when no change in position or size was noted with comparison of the last 2 radiographs. PROMs were recorded pre-operatively and at 6months, 12months, and 24month intervals. The following PROMs were collected: Ankle Osteoarthritis Score (AOS), PROMIS Global Physical Health, and Foot and Ankle Outcome Score (FAOS). The preoperative and latest follow-up scores for patients with two years of follow-up were analyzed. Results: 110 patients were enrolled in the study who had 2-year follow-up with twenty-one patients (19.1%) exhibiting a radiographic lucency. To date, our survivorship is 97.3%, of which 2 patients were revised for aseptic loosening; both reporting radiolucencies. The radiolucencies for one identified at 6months became progressive for both tibia and talus with cysts above 5mm requiring revision at 1.5years post op. The other requiring revision at 2years post-op reported progressive radiolucency. There was no difference in rates of survivorship with or without radiolucencies. One patient had subsidence which required revision. All patients with radiolucencies had significant improvements in all domains of the AOS, PROMIS, and FAOS Scores (p&lt; 0001). Radiolucency did not impact the PROs (AOA p=.741, PROMIS p=.964, FAOS p=.8937) in those with 2-year follow-up. Conclusion: Radiolucencies did not impact PROMs in patients undergoing implantation with a 4th generation total ankle replacement. In carefully selected patients, radiolucency did not correlate with an increased need for revision surgery nor had decreased survivorship.

Baseplate retroversion does not affect postoperative outcomes after reverse shoulder arthroplasty

There is concern that excessive glenoid component retroversion leads to altered biomechanics and baseplate failure in reverse shoulder arthroplasty (RSA). However, much of this has been rooted in the total shoulder arthroplasty experience. In the current literature, it is not well defined whether glenoid baseplate positioning in reverse arthroplasty affects functional outcomes. Our practice has been to preserve glenoid bone stock without aiming for a certain degree of retroversion. We aimed to evaluate the correlation between pre- and postoperative retroversion in a cohort of RSAs and determine the effect of glenoid retroversion on functional outcomes, range of motion, and postoperative complications. A retrospective review of patients who had an RSA between 2017 and 2019 was performed. Preoperative computed tomography scans were used to assess preoperative retroversion, and axillary radiographs were used for postoperative retroversion. Outcome measures included American Shoulder and Elbow Surgeons score, visual analog scale for pain score, Single Assessment Numeric Evaluation score, range of motion, radiographic lucency, and complications. A total of 271 patients were eligible for the study. There was a 76.9% 2-year follow-up rate. In total 161 patients had postoperative retroversion ≤15° (group A), and 110 patients had retroversion >15° (group B). There were no significant differences in American Shoulder and Elbow Surgeons, visual analog scale, or Single Assessment Numeric Evaluation scores. There were also no significant differences in postoperative range of motion. There was 1 baseplate failure in each group, and there was 1 patient in group B with asymptomatic radiographic loosening (baseplate at risk). The mean change in pre- to postoperative retroversion was 1° and 4° in groups A and B, respectively. There was no significant difference in postoperative functional outcomes, range of motion, or complications between patients who had baseplate retroversion ≤15° vs. those who had retroversion >15°.

Prevalence and Risk Factors Associated With Pelvic Rod/Screw Radiographic Lucency Following Scoliosis Surgery in Spastic Cerebral Palsy: A Longitudinal Study.

Radiographic lucency around a smooth pelvic rod (Galveston/unit rod technique) or sacroiliac/iliac screw following spinal fusion in children with nonambulatory spastic cerebral palsy (CP) has been described as a "windshield wiper" phenomenon. We evaluated demographics, radiographs, and complications in 101 cases from a single center to determine prevalence, risk factors, and complications associated with persistent radiographic lucency from 1 to 5 years following spinal fusion. Inclusion criteria were diagnosis of nonambulatory spastic quadriplegic CP [Gross Motor Function Classification System (GMFCS) IV-V], under 18 years of age, scoliosis treated by posterior fusion from upper thoracic to sacrum with pelvic fixation (Galveston rod, iliac screw, or sacroiliac screw), adequate radiographs (preoperative, immediate postoperative, first-year, and second-year), and minimum 5-year follow-up. We evaluated demographics, radiographic parameters, comorbidities, scoliosis curve type, type of pelvic screw/rod, use of off-set connector, screw width, associated with posterior column osteotomy and/or additional anterior spinal release concurrent with posterior spine fusion, and infection over the follow-up period. Specific attention was given to the area and shape of the radiographic lucency. The logistic regression analysis was performed for continuous and categorical variables to define risk factors ( P =0.05). In 101 patients, data were collected at mean intervals of 1-year, 2-year, and >5-year follow-up and were 12.9±1.5, 25.8±2.5, and 81.5±23.0 months, respectively. Prevalence of pelvic rod/screw radiographic lucency was unchanged at 33%, 35%, and 24% at 1-year, 2-year, and >5-year follow-up, respectively, and radiographic parameters did not change ( P >0.05). Furthermore, no risk factors or complications were associated with radiographic lucency around pelvic rods/screws ( P >0.05). In patients with spastic nonambulatory CP who had scoliosis treated with posterior spinal fusion from upper thorax to pelvis, the prevalence of pelvic rod/screw lucency is high. Persistent lucency >2 mm around pelvic implants is not clinically significant, does not warrant advanced imaging, or indicate a complication if stable over time and wider distally than proximally. Level III.

Early outcomes of augmented glenoid components in anatomic total shoulder arthroplasty: a systematic review.

BackgroundThe objective was to evaluate the short-term clinical and radiological outcomes following augmented anatomic total shoulder arthroplasty in patients with posterior glenoid deficiency.MethodsAn electronic search of EMBASE, MEDLINE, and PubMed identified studies reporting clinical and radiographic outcomes following augmented anatomic total shoulder arthroplasty among patients with posterior glenoid deficiency.ResultsNine studies including 312 shoulders underwent anatomic total shoulder arthroplasty using an augmented glenoid implant between 2015 and 2020. A statistically significant improvement in range of motion (ROM), visual analog scale (VAS), American Shoulder & Elbow Surgeons (ASES), Constant, University of California - Los Angeles and Simple Shoulder Test (SST) scores was demonstrated at mean follow-up of 37.1 months. Glenoid retroversion improved from 21.8° to 9.5°. At final follow-up, radiolucency was reported in 35.1% of shoulders. The 16° full-wedge augment led to higher and more severe radiographic lucency, while high peg perforation rates (44%) were observed among 5-mm augment stepped implants. The overall rate of complication was 2.6%. Rate of revision surgery was 1.9%.ConclusionsOverall, early- to mid-term outcomes following augmented anatomic total shoulder arthroplasty for posterior glenoid deficiency demonstrate good to excellent overall clinical results. More radiographic and clinical failures were reported in larger full wedge (16°) augments and stepped augments (5 mm). Prospective studies examining mid- and long-term outcomes will help further elucidate safety and efficacy of these relatively new implants.

Primary Tritanium acetabular components have increased rates of radiolucency associated with inferior clinical outcomes at short-term follow-up.

Cementless fixation is the standard for acetabular fixation in primary total hip arthroplasty (THA). There are various surface finishes thought to improve osteointegration, although literature regarding the long-term survival of some of these surfaces is limited. Regardless of design, primary stability is essential to allow for osteointegration. Previous studies have suggested an increased rate of radiolucency and compromised short-term functional outcomes using the Tritanium primary acetabular component (Stryker, Mahwah, NJ). The purpose of this study was to compare the primary Tritanium acetabular component to another contemporary acetabular component as a control group with an established clinical record. 444 consecutive, primary THAs performed by a single surgeon from 2008 to 2012 were reviewed. Patients were included if they had a minimum 1-year follow-up. Implant survivorship and modified Harris Hip Scores (mHHS) were recorded for all patients at final follow-up. Radiographs were evaluated by 2 surgeons at 6 weeks, 1 year, and the most recent follow-up for evidence of radiolucency and migration. Components were considered to have evidence of radiographic lucency if they had radiolucency in 2 or more DeLee zones. 198 patients met criteria for inclusion (96 Pinnacle, 102 Tritanium). Average follow-up was 28 (12-72) months. At final follow-up 6.2% of the Pinnacle cups and 29.4% of the Tritanium cups had radiographic evidence of loosening (p < 0.01). The average mHHS for the Tritanium group was 83.1, and 88.4 for the Pinnacle group (p < 0.01). Radiographic evidence of loosening also correlated with a lower mHHS: 75.5 versus 86.4 (p < 0.01). In patients that received Tritanium cups without screw fixation 44.6% showed radiographic evidence of loosening versus 8% that received screw fixation (p < 0.01). In total, 6 patients in the Tritanium group required revision for aseptic loosening of the acetabular component. The 30% rate of radiographic loosening in the Tritanium group was significantly higher than the Pinnacle group and correlated with an inferior clinical outcome. Interestingly the use of screw augmentation was protective against radiographic evidence of loosening. This suggests that the Tritanium component may be prone to fibrous in-growth because of inadequate primary stability.

Endodontic Peri-implant Defects: A New Disease Entity

Peri-implantitis is becoming a frequent complication observed around dental implants. An endodontic infection of a nearby tooth or an immediate implant placement in an inflamed bone socket from failing endodontic therapy has been associated with retrograde peri-implantitis (RPI), a condition that presents with radiographic lucency at the “apex” of an implant. However, current classification schemes do not capture endodontic lesions that may manifest as coronal or intrabony lesions associated with dental implants. As a result, such cases may be mistreated. Here we present for the first time 2 cases in which peri-implant bone loss occurred in the coronal half of the implant adjacent to a tooth with an endodontic-periodontic lesion and was resolved via endodontic therapy or tooth extraction as indicated. This proof of concept report aimed to introduce endodontic peri-implant (“endo-implant”) defects and increase vigilance, which may help prevent overtreatment or mistreatment of such cases.

High rate of tibial debonding and failure in a popular knee replacement: A cause for concern

BackgroundTotal knee arthroplasty (TKA) is a common orthopedic procedure with 975,739 performed in the UK between 2003 and 2016. The two most common prosthetics used are P.F.C. Sigma and NexGen. The aim of this study is to compare the experience of a single fellowship-trained arthroplasty surgeon at a single dedicated orthopedic hospital using both of these prosthetics over a 17-year period. MethodsThis study was carried out as a retrospective review. Information was gathered from a database of primary TKAs and revision TKAs, as well as medical records, correspondence and operative notes. ResultsA total of 1,511 TKAs were performed between 1999 and 2015 – with a further follow-up period of 2 years. There were 1,161 consecutive P.F.C. primary TKAs done from 1999 to April 2013, after which, 350 consecutive NexGen primary TKAs were performed. Between 2015 and 2017, 26 NexGen revisions were required. 23 (6.6%) of the NexGen knees were carried out for aseptic loosening. The average time for revision from the NexGen index surgery was 30.4 months. The failures all presented similarly – with the tibial component having collapsed into varus and radiographic lucency noted under the implant. ConclusionIn spite of changes in orthopedic practice and advances in implant technology over the time period of this study, we would not expect this level of implant failure from a surgeon who had no previous significant issues with aseptic loosening using a different prosthetic. Usage of the NexGen knee has been discontinued at this center.

Mid to long-term outcomes of the primary constrained condylar knee arthroplasty

BackgroundThe design of the constrained condylar knee (CCK) implant is meant to provide significantly more varus-valgus and anterior-posterior stability than a standard implant system. We hypothesized that while an increased constraint in design may lead to radiographic signs of loosening, the pain and functional outcome scores for patients with constrained implants remain acceptable at a mid to long term follow-up. Methods113 patients who underwent a primary TKA with a CCK implant by a single surgeon between the years 2008–2015 were contacted. 28 patients (30 knees) responded and returned for evaluation, which consisted of a Knee Society Score questionnaire and repeat radiographs. The average time to follow-up was 49.5 months. ResultsPain outcome scores (total of 30 knees) included, 19 excellent (63.3%), 7 good (23.3%) and 4 poor outcomes (13.3%). Function scores included 19 excellent (63.3%), 2 good (6.6%), 4 fair (13.3%), and 5 poor (16.7%) outcomes. There was a significant difference (p = 0.032) in pain scores between patients with no signs of radiographic lucency (mean pain score of 88.6) and patients with signs of implant loosening (mean pain score of 78.3). There was no significant difference in functional scores. ConclusionThe CCK implant is an acceptable option for a total knee arthroplasty which requires the extra stability not provided by a standard implant system. More studies with larger sample sizes, different populations and longer follow-up are needed to further evaluate outcomes in CCK implant recipients.

The Peritubercle Lucency Sign is a Common and Early Radiographic Finding in Slipped Capital Femoral Epiphysis.

A rotational mechanism of slipped capital femoral epiphysis (SCFE) in which the epiphyseal tubercle acts as a fulcrum has been recently described. However, there is limited radiographic evidence supporting this theory. We aimed to investigate whether a radiographic lucency around the epiphyseal tubercle (peritubercle lucency sign) could be observed before or at the diagnosis of a subsequent slip in patients initially presenting with unilateral SCFE. We evaluated 70 patients with unilateral SCFE who were followed until a contralateral slip was diagnosed, and 180 patients with unilateral SCFE who had no contralateral slip until skeletal maturity between 2000 and 2017. We revised anteroposterior and lateral radiographs from the initial presentation, surveillance, and diagnosis of a contralateral SCFE. The presence or absence of the peritubercle lucency sign in the contralateral initially uninvolved hip was recorded for every radiograph. The presence of hip pain, and the presence of classic radiographic parameters for SCFE diagnosis (epiphyseal tilt and Klein's line) were recorded when the peritubercle lucency sign became noticeable. The peritubercle lucency sign was observed in 84% [59/70; 95% confidence interval (CI), 73%-92%] of the patients who developed contralateral slip. Most patients (46/59=78%; 95% CI, 65%-87%; P<0.001) had the peritubercle lucency sign visible within 9 months after the initial diagnosis of unilateral SCFE. The sign preceded the definitive diagnosis of the contralateral slip at a median of 9 weeks (interquartile range, 0 to 10 wk). At the time of first observation of the peritubercle lucency sign, 36% (25/70; 95% CI, 25%-48%) of the patients were asymptomatic and 49% (34/70; 95% CI, 36%-61%) of the hips showed no abnormalities in the tilt angle or the Klein line. Among patients who did not experience a contralateral slip (n=180), the sign was observed in 2 patients (1.1%; 95% CI, 0.2%-4.4%). The sensitivity was 84% and specificity was 99%. A peritubercle lucency is an early imaging sign, present in >80% of contralateral slips following an initial presentation of unilateral SCFE. The presence of the peritubercle lucency sign may be helpful for contralateral hip surveillance. Future studies are necessary to establish the clinical validity of the peritubercle lucency sign and whether it may serve as a predictor of contralateral involvement. Diagnostic level III.

Radiographic comparison of finned, cementless central pegged glenoid component and conventional cemented pegged glenoid component in total shoulder arthroplasty: a prospective randomized study

Radiographic lucency of the glenoid component remains a problem after cement fixation in primary total shoulder arthroplasty. Glenoid component design likely contributes to rates of glenoid lucency. The purpose of this study was to prospectively compare radiographic lucency between a finned, cementless central pegged glenoid component (CL component) and a conventional cemented pegged glenoid component (P component) on immediate postoperative and minimum 2-year follow-up radiographs. Fifty-four patients undergoing total shoulder arthroplasty were prospectively randomized to receive an all-polyethylene CL component or a conventional all-polyethylene P component. Three raters graded glenoid lucency and bone interdigitation on immediate postoperative and latest follow-up radiographs. Patients who had undergone revision surgery or had died before evaluation were excluded. Minimum 2-year follow-up was required for inclusion of radiographic evaluation. Fifty patients met inclusion criteria; 42 patients (84%; 20 CL and 22 P) were available for follow-up with the original glenoid implant in place. The mean follow-up duration was 35 months (24-64 months). There were no significant differences in glenoid radiolucency between CL (1/20 [5%]) and P (2/22 [9%]) components at last follow-up (P = .999). Five patients (25%) in the CL group had bone interdigitation. No instances of aseptic glenoid loosening occurred. There were no significant differences in the rate of glenoid lucency between the 2 groups at immediate or an average 35-month follow-up. Both techniques appear to be viable options for initial glenoid component fixation, with CL components allowing possible osseointegration, imparting potential long-term stability.

Radiographic and clinical comparison of pegged and keeled glenoid components using modern cementing techniques: midterm results of a prospective randomized study

Glenoid component loosening remains a significant issue after anatomic shoulder arthroplasty. Pegged glenoid components have shown better lucency rates than keeled components in the short term; however, midterm to long-term results have not fully been determined. We previously reported early outcomes of the current randomized controlled group of patients, with higher glenoid lucency rates in those with a keeled glenoid. The purpose of this study was to evaluate the radiographic and clinical outcomes of these components at minimum 5-year follow-up. Fifty-nine total shoulder arthroplasties were performed in patients with primary glenohumeral osteoarthritis. Patients were randomized to receive either a pegged or keeled glenoid component. Three raters graded radiographic glenoid lucencies. Clinical outcome scores and active mobility outcomes were collected preoperatively and at yearly postoperative appointments. Of the 46 shoulders meeting the inclusion criteria, 38 (82.6%) were available for minimum 5-year radiographic follow-up. After an average of 7.9 years, radiographic lucency was present in 100% of pegged and 91% of keeled components (P = .617). Grade 4 or 5 lucency was present in 44% of pegged and 36% of keeled components (P = .743). There were no differences in clinical outcome scores or active mobility outcomes between shoulders with pegged and keeled components at last follow-up. Within the initial cohort, 20% of the keeled shoulders (6 of 30) and 7% of the pegged shoulders (2 of 29) underwent revision surgery (P = .263). Kaplan-Meier analysis showed no significant difference in survival rates between groups (P = .560). At an average 7.9-year follow-up, non-ingrowth, all-polyethylene pegged glenoid implants are equivalent to keeled implants with respect to radiolucency, clinical outcomes, and need for revision surgery.

Radial Neck Dilatory Remodeling After Radial Head Arthroplasty With an Uncemented, Press Fit, Fully Chemically Etched Stem Design

To compare the radiographic outcomes of 2 widely used side loading, press fit, RHA implants used to reconstruct complex elbow trauma. Retrospective cohort study. Level-1 Academic trauma center. Patients undergoing RHA. Cohort 1 received Synthes Radial Head Prosthesis. Cohort 2 received Biomet ExploR Radial Head Replacement. Radial neck dilatory remodeling. Eighty-two subjects were included in final analysis, 63 from the Biomet Cohort, and 19 from Synthes cohort. Demographic and injury characteristics were similar among cohorts. Radial neck dilatory remodeling as well as periprosthetic radiographic lucency were seen significantly more frequently and to a significantly greater degree in the Synthes cohort. The average percentage of dilatory remodeling of the Synthes cohort was 34.9% and that of the Biomet cohort was 2.7%. There were no differences in rates of revision surgery. Our study demonstrates significant radiographic differences between 2 frequently used RHA implants. Radial neck dilatory remodeling is a common, rapidly progressive, and dramatic finding frequently seen with the Synthes Radial Head Prosthesis. Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Tritanium acetabular wedge augments: short-term results.

Reconstruction of acetabular defects in total hip arthroplasty (THA) presents a great challenge to orthopaedic surgeons. Previous studies have reported on the use and outcomes of trabecular metal acetabular augments for the reconstruction of acetabular defects. However, no study has been conducted evaluating the short-term results of tritanium acetabular wedge augments for the reconstruction of acetabular defects in THA. A retrospective study was conducted using a prospective database at a single institution including primary and revision THA patients from January 2013 to December 2014. Patients were included if they received a tritanium acetabular wedge augment system and had a minimum of 2-year follow-up (average 2.2 years ±0.3, range, 2-2.6 years). Demographic data and outcomes data [Harris Hip Score-HHS and Short Form (SF)-36] was collected. Radiographic data was also collected on THA revision cases (Paprosky classification), developmental dysplasia of the hip (DDH) cases (Crowe classification), and radiographic follow-up using DeLee and Charnley's classification system. There were 4 revision THA patients, 3 DDH patients, and 1 patient with posttraumatic arthritis. At the latest radiographic follow-up, there were no lucent lines in DeLee and Charnley Zones I, II or III. During the follow-up period, there was no open revision surgery. The SF-36 physical score significantly improved from preoperative measurement (29.6±2.2) to postoperative measurement (52.2±8.7, P=0.003), and the SF-36 mental score also significantly improved from preoperative assessment (34.5±4.5) to postoperative assessment (52.2±7.5, P=0.003). Total HHS scores also significantly improved postoperatively (P=0.02), with significant improvements in both the pain score (P=0.01) and function score (P=0.02). Tritanium acetabular wedge augments in this short follow-up case series exhibit high clinical outcome scores, no radiographic lucency, and no early failures.

Unexpected radiographic lucency following grafting of bone defects with calcium sulfate/tricalcium phosphate bone substitute.

To report the development of unexpected radiographic lucency (URL) corresponding to the use of a commercially available calcium sulfate/tricalcium phosphate composite used to treat benign osseous lesions. This is a retrospective comparative study of patients with and without URL after treatment with curettage and grafting with calcium sulfate/tricalcium phosphate. The charts of 87 patients meeting the inclusion criteria were reviewed for demographic, clinical, and radiographic data. The group with URL was compared to those with more typical patterns of graft incorporation. Thirteen of 87 cases (15%) showed URL. There was no difference with respect to the pathologic subtype, anatomic location, or specific bone for the presence of URL. Of patients with URL, one (7.7%) required reoperation and regrafting, whereas among patients without URL, five (6.7%) had clinical complications, with one requiring reoperation and regrafting, and one requiring radiofrequency ablation. The majority of patients treated with calcium sulfate/tricalcium phosphate cementing after curettage of low-grade bone lesions go on to uneventful healing in our series. In a minority of patients, URL occurs in lieu of the more typical pattern of centripetal incorporation. However, there is no increase in complications associated with URL. Based on these findings, patients should be informed of the possibility of this risk, although there appears to be little risk of clinically relevant adverse consequences. Physicians should be aware of this complication in order to avoid mistaking it for recurrence of the primary lesion.

Radiographic Lucency around Pedicle Screws with Cobalt Chromium Rod Constructs in the Setting of Lumbar Fusion

Background Context: Hybrid spinal implants that combine cobalt-chrome rods with titanium screws have been introduced with the goal of reducing the profile of implants used for lumbar fusion. 4.5mm and 4.75mm cobalt-chrome rods have been reported by the manufacturers as having similar results in biomechanical testing to conventional 5.5mm titanium rods, however little is known about the long-term clinical performance of these implants. This report discusses an interesting radiographic finding routinely encountered in our practice following use of these implants. Purpose: To describe the occurrence of radiographic lucency surrounding pedicle screws following the use of low-profile hybrid spinal implants for instrumented posterior lumbar fusion. Study Design: Case report. Methods: This is an observational case series of 14 patients undergoing lumbar fusion instrumented with hybrid cobalt/chrome – titanium implants. All cases involved instrumented posterior lumbar fusion for the treatment of degenerative spondylolisthesis. Patients were followed for one year with radiographic evaluation of both screw lucency and bony fusion as well as subjective outcomes including visual analog scale (VAS) pain score and Oswestry disability index (ODI). Results: At one year post-operative, all 14 patients had radiographic lucency around at least two pedicle screws in the construct despite radiographic bony fusion. All patients reported subjective improvement in VAS score and ODI, and all patients returned to work within 3 months post-operative. Conclusion: We note a 100% rate of pedicle screw lucency in our series of patients undergoing posterior spinal fusion instrumented with hybrid lowprofile cobalt-chrome implants. Lucency around pedicle screws has been previously associated in the literature with screw loosening, micro motion, and pseudo arthrosis. Despite this observation, the patients in our series subjectively report favorable outcomes. The significance and cause of lucency around pedicle screws with these low-profile implants is unknown, but may be due to decreased construct stiffness related to smaller rod diameter. Long-term experience with these implants is lacking and further studies are warranted.

Lucent lines and glenoid components: What do they portend?

Glenoid component radiolucent lines following total shoulder arthroplasty are not uncommon postoperative radiographic findings and their incidence varies. With time, a certain percentage of radiolucent lines progress and potentially compromise component stability. The incidence of radiographic lucency progresses from 9% to 27% and then 73% at 2, 5, and 15 years, respectively. Radiolucent lines can be caused by posterior glenoid wear, inflammatory arthritis, design factors such as a metal-backed glenoid implant, and improper implantation techniques where the prosthesis is not fully seated or cement is used to fill a defect. Intraoperative techniques to prevent lucent lines include removing minimal bone from the glenoid vault and pressurizing cement into the cancellous bone at time of glenoid component implantation. Furthermore, a pegged glenoid component rather than a keel type is preferred, as this has been associated with a lower incidence of radiolucent lines.