Periprosthetic Lucency Research Articles

Comparing Rates of Radiographic Baseplate Loosening Between Cement and Cementless INFINITY Total Ankle Prostheses

Category: Ankle Arthritis Introduction/Purpose: Total ankle replacement has risen in popularity as the contemporary treatment-of-choice for end-stage ankle osteoarthritis. INFINITY™ Total Ankle System (Stryker, Kalamazoo, MI) is one of the most frequently used ankle prostheses. Prior studies established positive functional outcomes; however, aseptic baseplate loosening has reported to occur in approximately one-third of patients. Aseptic baseplate loosening is seen radiographically either as shift in talar or tibial components or evidence of periprosthetic lucency. Aseptic baseplate loosening with persistent pain defines prosthesis failure, thus an indication for early surgical revision. Implementing bone cement may fixate and stabilize prostheses, potentially reducing incidence of aseptic baseplate loosening. This study aimed to determine if patients with cemented INFINITY total ankle prostheses had different incidence of aseptic baseplate loosening than those with cementless prostheses. Methods: Patients who underwent total ankle arthroplasty using the INFINITY total ankle prosthesis system between January 2016 and May 2022 (n = 28) were retrospectively identified using keyword search for “infinity” and Current Procedural Terminology (CPT) code 27702. Fourteen patients had prostheses affixed with cement, and fourteen patients had prostheses that were not cemented. Preoperative, immediate postoperative, and most recently available anteroposterior (AP), mortise, and lateral ankle X- rays were reviewed. Tibiotalar angle, talar tilt, and presence of visible postoperative lucency were assessed independently by two reviewers. Wilcoxon rank-sum test on quantitative variables and chi-square test on categorical variables were performed with 0.05 significance level. Results: Inter-rater reliability was above 94% for all measurements. Comparing the cemented to cementless sample group, difference in average age (59.5 years vs. 56.5 years, p=0.32) and sex (57.1% vs. 50.0% female, p=0.70) were not statistically significant. Pre-operative and immediate post-operative tibiotalar and talar tilt angles were not statistically significantly different between cement and cementless groups (p>0.31 for all comparisons). Only one patient in the cement group had evidence of periprosthetic lucency in the immediate postoperative period. Median follow-up was 362.5 days and 544.5 days in the cement and cementless group, respectively (p=0.52). Follow-up tibiotalar angles and talar tilt angle between cement and cementless groups were not significantly different (p>0.51 for all comparisons). Periprosthetic lucency occurred in 50% of both groups in the follow- up period (p=1.0). Conclusion: Patients with cemented INFINITY total ankle prostheses had equal incidence of aseptic baseplate loosening compared to patients with cementless prostheses. Continuing to examine methods for reducing incidence of baseplate loosening is significant for potentially reducing rate of early prosthesis revision and prosthesis failure, consequently improving quality of life for patients.

Survivorship, Clinical Outcomes, and Radiographic Complications in the Infinity Total Ankle Arthroplasty at Mid-term (Minimum 5-Year) Follow-up

Category: Ankle Arthritis; Ankle Introduction/Purpose: As the frequency of total ankle arthroplasties (TAA) performed annually has increased significantly over the past decade, several novel TAA implants have entered the market. The Infinity TAA (Stryker, Mahwah, NJ) is a low-profile fixed- bearing implant that was approved for use in the United States in 2014. Although the short-term survivorship and complication rates of the Infinity TAA have been well documented in the literature, mid- to long-term outcome studies of this implant are limited. The aim of this study was to describe the survivorship, reoperation rate, and radiographic and clinical outcomes of the Infinity implant at minimum 5-year follow-up. We hypothesized that there would be no significant drop-off in clinical outcome or alignment from 2-year to 5-year follow-up. Methods: This is a single-institution retrospective review of patients who underwent primary TAA with the Infinity implant from July 2014 to April 2017. Four fellowship-trained foot and ankle surgeons contributed patients. Out of 74 identified ankles, 65 ankles in 64 patients had minimum clinical follow-up of 5 years (mean, 6.5; range, 5.0-8.0) and were included for analysis. Medical records were reviewed to record demographics, surgical data, complications, reoperations, and revisions. Radiographs were assessed to measure preoperative and postoperative alignment, and the incidence of postoperative peri-implant lucencies and cysts. Preoperative, 2-year, and 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscores in the categories of Pain, Symptoms, Activities of Daily Living, Sports, and Quality of Life were obtained. The primary outcome was 5-year survivorship. Secondary outcomes were reoperations with retention of tibial and talar components, radiographic alignment, peri-implant lucencies/cysts, and clinical outcomes (FAOS) scores. Results: Implant survivorship at 5 years was 93.8%, with 4/65 revisions. Three revisions occurred less than 2 years from the index surgery (2/3 for tibial subsidence; 1/3 for tibial and talar subsidence). The fourth revision occurred at 7.1 years due to cystic changes with tibial and talar subsidence. There were 11 reoperations in 10 ankles. Alignment correction achieved surgically (preop coronal deformity 9.0 ± 6.8°; 1Y postop 1.6 ± 1.5°) was maintained at final radiographic follow-up (1.8 ± 1.7°; P = 0.32). There were 16 ankles (24.6%) with peri-implant radiographic abnormalities: 14 cases of lucency (14 tibia, 0 talus) and 3 cases of cysts. FAOS outcomes demonstrated significant improvement from preop to postop in all five domains at 2 years, which were maintained at 5 years. Conclusion: The mid-term outcomes of the Infinity implant in this single-institution study demonstrated good survivorship of 93.8% and improved clinical outcomes at mean 6.3-year follow-up. This was a mid-term follow-up to the 2-year outcome study published at this institution. Radiographic assessment at final follow-up demonstrated that alignment correction was maintained, and there was a 21.5% incidence of asymptomatic periprosthetic lucencies. These results demonstrate that there was no significant change in radiographic or clinical outcomes with this implant after 5 years, which is valuable for surgeons in terms of counseling and following patients in the immediate and mid-term postoperative period.

ARTIFICIAL INTELLIGENCE CAN IDENTIFY FAILING TOTAL HIP ARTHROPLASTIES BEFORE RADIOLOGICAL FEATURES OR A DROP IN PROMS SCORES

Over 8000 total hip arthroplasties (THA) in the UK were revised in 2019, half for aseptic loosening. It is believed that Artificial Intelligence (AI) could identify or predict failing THA and result in early recognition of poorly performing implants and reduce patient suffering.The aim of this study is to investigate whether Artificial Intelligence based machine learning (ML) / Deep Learning (DL) techniques can train an algorithm to identify and/or predict failing uncemented THA.Consent was sought from patients followed up in a single design, uncemented THA implant surveillance study (2010–2021). Oxford hip scores and radiographs were collected at yearly intervals. Radiographs were analysed by 3 observers for presence of markers of implant loosening/failure: periprosthetic lucency, cortical hypertrophy, and pedestal formation.DL using the RGB ResNet 18 model, with images entered chronologically, was trained according to revision status and radiographic features. Data augmentation and cross validation were used to increase the available training data, reduce bias, and improve verification of results.184 patients consented to inclusion. 6 (3.2%) patients were revised for aseptic loosening. 2097 radiographs were analysed: 21 (11.4%) patients had three radiographic features of failure.166 patients were used for ML algorithm testing of 3 scenarios to detect those who were revised. 1) The use of revision as an end point was associated with increased variability in accuracy. The area under the curve (AUC) was 23–97%. 2) Using 2/3 radiographic features associated with failure was associated with improved results, AUC: 75–100%. 3) Using 3/3 radiographic features, had less variability, reduced AUC of 73%, but 5/6 patients who had been revised were identified (total 66 identified).The best algorithm identified the greatest number of revised hips (5/6), predicting failure 2–8 years before revision, before all radiographic features were visible and before a significant fall in the Oxford Hip score. True-Positive: 0.77, False Positive: 0.29.ML algorithms can identify failing THA before visible features on radiographs or before PROM scores deteriorate. This is an important finding that could identify failing THA early.

Tibial Component Subsidence in a Total Ankle System Comparing Standard Technique Versus a Hybrid Technique

Total ankle arthroplasty (TAA) is a viable treatment option for end-stage ankle arthritis. However, implant survivorship remains an important consideration. Concerns regarding early component loosening with the low-profile tibial tray utilized by fourth-generation TAA systems have been raised in the literature. We have previously described our preliminary outcomes of a hybrid technique combining a stemmed intramedullary tibial component with a chamfer-cut talar component for TAA. A retrospective study comparing short-term outcomes of the tibial component between a standard fourth-generation TAA system versus our hybrid technique was performed. 46 patients with a minimum of 1-year follow up were included in the analyses. There were 25 subjects in the standard implant cohort utilizing a low-profile tibial tray, and 21 subjects in the hybrid group utilizing a stemmed intramedullary tibial component. No statistically significant difference between the demographics of each group was found. The rate of tibial component subsidence was 8% (n = 2) in the standard implant group, and 0% (n = 0) in the hybrid group, though this did not meet statistical significance (p = .49). Mean time to subsidence was 6 months, and revision rate due to tibial component subsidence was 2.1% (n = 1). Periprosthetic lucency was present on most recent follow-up radiographs in 32% and 9.5% of ankles in the standard and hybrid groups, respectively (p = .08). Despite prior concerns for tibial component subsidence with the standard fourth-generation system, we demonstrated low rates in both implant groups. Additional studies are needed to further explore factors that may predispose patients to early tibial component subsidence and resulting implant failure.

After Total Ankle Arthroplasty, When Does Bone Perfusion and Metabolic Activity at the Bone-Implant Interface Normalize? A PET/CT Study

Category: Ankle Arthritis Introduction/Purpose: Radionuclide bone scintigraphy in combination with computed tomography (CT) has been used to evaluate painful total hip and knee arthroplasties, and has also been used in the evaluation of the painful total ankle arthroplasty (TAA). Increased tracer uptake around implants may indicate loosening, but uptake characteristics of bone-seeking radiopharmaceuticals in asymptomatic total ankle patients have not been clarified. While findings of increased metabolic activity may prompt surgical intervention, there has been no work performed to define when postoperatively periprosthetic activity normalizes, if at all. In this study, we plan to establish normative data on 18F sodium fluoride (18F-NaF) positron emission tomography/CT (PET/CT) uptake ratios around TAA implants at various time intervals after surgery in asymptomatic TAA patients. Methods: The majority of the arthroplasty literature has investigated use of SPECT/CT performed with 99mTc-labeled bisphosphonates. However, data suggest that 18F-NaF PET/CT may be superior for this indication, with more favorable pharmacokinetics and similar sensitivity to detect aseptic loosening. In the present study, asymptomatic patients who underwent TAA with a modern fixed-bearing TAA prosthesis (either the Wright Infinity Adaptis or Exactech Vantage prosthesis) for posttraumatic arthritis were eligible for inclusion. Patients with ipsilateral hindfoot fusion and with any periprosthetic lucencies or cysts were excluded. Patients were enrolled at one of four time intervals following TAA: 6, 12, 18, or 24 months. Standard uptake values were measured at the bone-implant interface for the tibial and talar components on static PET, in regions of interest defined on axial CT scan slices. Periprosthetic bone blood flow (K1) and bone turnover (flux) were assessed at each time interval in each periprosthetic region using dynamic PET. Results: Sixteen asymptomatic patients underwent PET/CT: 4 patients at 6 months postoperatively, 6 at 12 months, and 6 at 24 months. We are currently still in data collection and at this time only 2 patients at 18 months have completed the scan, therefore their data were excluded. The average age was 65 years (range, 55 to 80) and 6 patients were female (38%), with individual patient data shown in the Table. Talar K1 and flux both appeared to increase from 6 to 12 months, and decrease between 12 and 24 months, although there was no statistically significant difference between timepoints. Overall tibial K1 and flux appeared to decrease slightly from 6 to 12 months, and stayed relatively stable between 12 and 24 months, again with no significant difference between timepoints (Figure). Conclusion: There is currently no normative data to help guide interpretation of radionuclide bone scintigraphy for the painful TAA. The present study utilizing 18F-NaF PET/CT scans demonstrates that even in asymptomatic patients, periprosthetic bone blood flow and bone turnover remain elevated up to 24 months following modern fixed-bearing TAA. Not only do these values remain elevated at 24 months, but we found that there does not appear to be any significant decrease in either measurement over time from 6 to 24 months postoperatively. Our findings suggest that radionuclide bone scintigraphy should be cautiously interpreted when performed within 2 years of TAA.

Early Radiographic and Clinical Outcomes of a Novel, Fixed-Bearing Fourth-Generation Total Ankle Replacement System.

The Cadence Total Ankle System is a 2-component, fixed-bearing fourth-generation total ankle arthroplasty (TAA) system that was introduced for clinical use in 2016. The purpose of this study was to report non-inventor, non-industry funded survivorship, radiographic and clinical outcomes, and early complications following use of this implant at a minimum of 2 years. This single-center retrospective study included patients who underwent TAA by 2 surgeons with this novel fixed-bearing system between January 2017 and September 2018. Forty-eight patients were evaluated at an average of 33.6 months. Radiographic outcomes included preoperative and postoperative tibiotalar angle on anteroposterior radiographs of the ankle, sagittal tibial angle (STA) on lateral radiographs of the ankle, and periprosthetic lucency formation and location. Revision and reoperation data were collected, and patient-reported outcomes were assessed using Patient Reported Outcomes Measurement Information System (PROMIS). Subgroup analysis assessed associations between preoperative deformity, postoperative implant alignment, PROMIS scores, and periprosthetic lucency formation. Survivorship of implant was 93.7%, with 3 revisions, 1 due to infection and 2 due to loosening of the implant (1 tibial and 1 talar component). Three patients had reoperations (6.3%): 2 for superficial infection and 1 for gutter debridement due to medial gutter impingement. Fifteen patients (35.8%) developed periprosthetic lucencies, all on the tibial side. PROMIS scores improved after surgery in all domains except Depression. Patients with significant postoperative periprosthetic lucency had worse postoperative PROMIS Physical function scores than patients without lucency (P < .05). This study demonstrated excellent minimum 2-year clinical and radiographic outcomes and low revision and reoperation rates of this new fourth-generation TAA system. Future studies with longer follow-up, especially on patients with periprosthetic lucency, are necessary to investigate the long-term complications and understand the long-term functional and radiographic outcomes of this implant.

Anatomic Monopolar Press-fit Radial Head Arthroplasty; High Rate of Loosening at Mid-Term Follow Up.

Radial head arthroplasty (RHA) is used for the management of unstable or unreconstructable injuries of the radial head. Our aim was to investigate clinical and radiographic outcomes in patients treated with the Acumed anatomic radial head press-fit system for trauma. Clinical and radiographic assessment of RHAs undertaken for trauma with minimum 2-year follow-up. 16 consecutive patients, mean age 53 (21-82) and 66 month ± 27 (26-122) clinical follow-up were included. There were marked radiographic changes with 11/16 showing periprosthetic lucent lines and 13/16 showing subcollar osteolysis. Radiographic changes occurred early post-surgery. Stem loosening was associated with larger cantilever quotients (0.47 vs 0.38, p = 0.004). Overall survivability was 81.2%, with 3 RHAs removed. Clinical outcomes for the retained RHAs were acceptable with mean flexion 134°, extension deficit of 10°, pronation of 82°, and supination of 73°. Mean VAS scores were 8.5 ± 14.4, QuickDASH 13.8 ± 18.9, Mayo Elbow Performance Scores were 91.5 ± 12.5 with no poor scores. Mid-term clinical functional outcomes following the Acumed anatomic RHA are acceptable in most cases. However, in view of the extensive periprosthetic lucencies and surgical removal due to loosening, patients should be cautioned when consented for implantation of the prosthesis, especially if a large collar is anticipated.

Long-term outcomes of open arthrolysis combined with radial head arthroplasty for post-traumatic elbow stiffness: results are durable over 8 years.

Post-trauma elbow stiffness (PTES) is a common complication after elbow trauma that causes severe upper limb disability. Open elbow arthrolysis (OEA) with radial head arthroplasty (RHA) is an effective method to treat PTES with rotation limitation, or persistent pain/instability after radial head resection. However, no long-term results have been reported for this technique. This study aimed to show the clinical and radiographic outcomes of OEA with RHA over 8 years and compare its efficacy at 3 years (short-term). Patients with PTES treated by OEA with RHA between September 2010 and December 2012 were retrospectively reviewed. Seventeen patients were followed up over 8 years (range, 100-106 months). A bipolar prosthesis of RHA was performed during OEA. Preoperative, 3-year, and 8-year elbow and forearm motion, upper limb function, radiographic outcomes, and complications were recorded. Clinically important improvements in elbow motion and forearm rotation were obtained, from 34° and 58° preoperatively, to 109° and 135° at 3 years, which were maintained over 8 years, to 113° (P = .262) and 134° (P = .489). The Mayo Elbow Performance Index had clinically important increases from the preoperative level of 58 to 94 points at 3 years, and was maintained over 8 years (95 points, P = .422), with 100% reporting excellent to good outcomes. Pain and nerve symptoms were also improved. Complications consisted of new-onset ulnar nerve symptoms in 1 patient, nonclinically significant heterotopic ossification recurrence in 3, humeroulnar arthritis exacerbation in 4, and periprosthetic lucency in8. OEA with RHA yielded satisfactory short-term outcomes for PTES at 3 years, with substantial improvements in elbow mobility and function, and the results were durable over the long term (8 years).

Midterm Survivorship of the INBONE II Total Ankle Arthroplasty

The use of total ankle arthroplasty (TAA) in the treatment of ankle arthritis has grown substantially as advancements are made in design and surgical technique. Among the criteria guiding the choice between arthroplasty and arthrodesis, the long-term survival and postoperative outcomes are of crucial importance. Although outcomes of the INBONE I have been published, there is limited midterm survival data for the INBONE II. The purpose of this study was to determine the radiographic and patient-reported outcomes, and survivorship of this prosthesis in patients with a minimum 5-year follow-up. We retrospectively identified 51 ankles (46 patients) from 2010 to 2015 who underwent TAA with the INBONE II prosthesis at our institution. Of these, 44 cases had minimum clinical follow-up of 5 years (mean, 6.4; range 5-9). Median age was 66 years (range 42-81) and median BMI was 27.5 (range 20.1-33.0). A chart review was performed to record the incidence of revision and reoperation. Preoperative and postoperative radiographs were analyzed to assess the coronal tibiotalar alignment (TTA), the talar inclination angle, and the presence of periprosthetic lucencies and cyst formation. Preoperative and minimum 5-year postoperative Foot and Ankle Outcome Score (FAOS) subscales were compared. Survivorship was determined by incidence of revision, defined as removal of a metallic component. The survivorship at 5 years was 98% and the rate of reoperation was 7.8% (n = 4); 2 patients underwent irrigation and debridement for infection, 1 patient underwent a medializing calcaneal osteotomy, and 1 patient underwent open gutter debridement, 1 patient underwent a revision of a subsided talar component at 3.2 years after index surgery. Average postoperative TTA was 88.6 degrees, with 42 rated as neutral (85-95 degrees), 2 varus (<85 degrees), and no valgus (>95 degrees) ankles. At final follow-up, asymptomatic periprosthetic cysts were observed in 8 patients. All FAOS domain scores improved between preoperative and final follow-up. At midterm follow-up, we observed significant improvement in radiographic alignment and patient-reported outcome scores for the INBONE II total ankle prosthesis. In addition, this cohort has had a relatively low reoperation rate and high survivorship. Level IV, case series.

Predictive factors affecting long-term survivorship of ASR metal-on-metal total hip arthroplasty.

Introduction: We present the outcome of 154 ASR (Articular Surface Replacement) hips performed at the P.D Hinduja Hospital and Medical Research Centre in terms of revision rate, metal ion levels, and factors affecting survivorship. Further, determined the importance of serial metal ion estimation over single value with poorly functioning arthroplasties. Methods: A retrospective study of 154 ASR arthroplasties (136 patients) performed from April 2005 till March 2010 was conducted. Ninety-seven patients were available for final analysis. All patients were assessed for symptoms, radiographs, blood metal (chromium and cobalt), metal artefact reduction sequence (MARS), magnetic resonance imaging (MRI), and computerized tomography (CT). Results: Female gender, smaller femoral head, patients with a rising level of metal ion levels were more likely to have revision surgery. However, abnormal acetabular inclination/anteversion was not associated with the occurrence of raised metal ion levels, ARMD (adverse reaction to metal debris) or revision surgery. Patients with raised metal ion levels were more likely to have periprosthetic lucency, ARMD, and revision surgery. Median metal levels increased initially for the first three years. Still, patients who required revision surgery continued to have a metal ion rise until the point when revision surgery was performed. In contrast, patients who had a fall in metal ion levels did not require revision. Conclusion: A single metal ion value is less predictive of failing arthroplasties; instead, a rising trend of metal ion levels can better delineate arthroplasties which will require revision. ASR hips whose blood ion levels fell after an initial rise and showed a declining trend did well.

Short- to mid-term outcomes of radial head replacement for complex radial head fractures.

BackgroundThe purpose of the current study was to investigate short- to mid-term outcomes and complications following radial head replacement (RHR) for complex radial head fractures and to identify factors associated with clinical outcomes.MethodsTwenty-four patients with complex radial head fractures were treated by RHR. The mean age of the patients was 49.8 years (range, 19–73 years). Clinical and radiographic outcomes were evaluated for a mean follow-up period of 58.9 months (range, 27–163 months) using the visual analog scale (VAS) score for pain, the Mayo elbow performance score (MEPS), the quick disabilities of the arm, shoulder and hand (Quick-DASH) score, and serial plain radiographs. Complications were also evaluated. ResultsAt the final follow-up, the mean VAS score, MEPS, and Quick-DASH score were 0.6±1.1, 88.7±11.5, and 19.4±7.8, respectively. The mean range of motion was 132.7° of flexion, 4.7° of extension, 76.2° of pronation, and 77.5° of supination. Periprosthetic lucency was observed in six patients (25%). Heterotopic ossification was observed in four patients (16.7%). Arthritic change of the elbow joint developed in seven patients (29.2%). Capitellar wear was found in five patients (20.8%). Arthritic change of the elbow joint was significantly correlated with MEPS (P=0.047). Four cases of complications (16.6%) were observed, including two cases of major complications (one stiffness with heterotopic ossification and progressive ulnar neuropathy and one stiffness) and two cases of minor complications (two transient ulnar neuropathy).ConclusionsRHR for the treatment of complex radial head fractures yielded satisfactory short- to mid-term clinical outcomes, though radiographic complications were relatively high.

The INFINITY Total Ankle Prosthesis: Outcomes at Short Term Follow-up

Category:Ankle Arthritis; Ankle; OtherIntroduction/Purpose:The INFINITY total ankle prosthesis remains the most widely used 4th generation total ankle arthroplasty (TAA) system in the United States. The purpose of the present study was to assess outcomes for the INFINITY prosthesis at short-term follow-up.Methods:All patients who underwent primary TAA with INFINITY between August 2015 and June 2018 at a single institution and who were at least 1 year postoperative were included. A total of 55 ankles with a mean follow up 22 (range, 12-43) months met the criteria. Weightbearing radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6- 8 weeks postoperatively, and at the most recent follow-up. Medical records and charts were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al. and Glazebrook at el., respectively.Results:Overall survivorship for the INFINITY prosthesis was 98.2%. Coronal and sagittal tibiotalar alignment improved after surgery (p<.001, p=0.09), and was maintained during the latest follow-up (p=0.62, p=0.47). One ankle (1.8%) required early component revision; while 5 (9.1%) required non-implant related revision. Postoperative periprosthetic lucency’s were observed in nineteen ankles (34.5%); most of which were non-progressive (17 ankles, 89.5%). Thirteen complications (3 high grade, 3 intermediate, and 7 low) in 11 ankles (20%) were recorded according to the Glazebrook classification system.Conclusion:INFINITY survivorship was 98.2% at a mean of 1.8 years of follow-up, with only 1 ankle requiring prosthetic revision. Additional studies with longer follow-up are warranted for 4th generation TAA prostheses.

The INFINITY Total Ankle Prosthesis: Outcomes at Short-Term Follow-up

The INFINITY total ankle prothesis remains the most widely used fourth-generation total ankle arthroplasty (TAA) system in the United States. The purpose of the present study was to assess radiographic outcomes for INFINITY at short-term follow-up. All patients who underwent primary TAA with INFINITY between August 2015 and June 2018 at a single institution and who were at least 1 year postoperative were included. A total of 55 ankles with a mean follow up 22 months (range, 12-43 months) met the criteria. Weightbearing radiographs were assessed using coronal and sagittal alignment parameters preoperatively, at 6 to 8 weeks postoperatively, and at the most recent follow-up. Medical records and charts were reviewed and revisions, reoperations, and complications were classified according to the criteria established by Vander Griend et al and Glazebrook at el, respectively. Overall, INFINITY survivorship was 98.2%. Coronal and sagittal tibiotalar alignment improved after surgery (P < .001, P = .09, respectively), and was maintained during the latest follow-up (P = .62, P = .47, respectively). Only 1 ankle (1.8%) required early revision; while 5 (9.1%) indicated non-implant-related revision; 85.5% required no reoperation. In nineteen ankles (34.5%), postoperative periprosthetic lucency was observed; most were not progressive (17 ankles, 89.5%). Twelve complications (3 high grade, 3 intermediate, and 6 low grade) in 11 ankles (20%) were recorded according to the Glazebrook classification system. INFINITY survivorship was 98.2% at a mean of 1.8 years of follow-up, and only 1 ankle required prosthetic revision. Additional studies with longer follow-up are warranted for fourth-generation TAA prostheses. Level IV: Case series.

Cementless curved short stem shoulder prostheses with a proximal porous coating: ingrowth properties at 2-5 years of radiological follow-up with clinical correlation

Little is known about the way the newest generation of stems integrate into the proximal humerus and their effect on the surrounding bone. Factors that may influence ingrowth have not been investigated. A consecutive cohort study was conducted that examined 74 anatomical, reverse, or pyrocarbon hemiprostheses, using a curved modular short stem with a proximal porous coating 2-5 years postoperatively (mean 35 months). X-rays were reviewed by 2 examiners independently. Bone loss was scored with 1 point per zone with partial and 2 points per zone with complete resorption (10 zones). The Constant score was used for clinical correlation. Multiple linear regression was employed to investigate correlations between variables. No subsidence or shift of the stems occurred. Two of 74 patients showed 1 zone of periprosthetic lucency of 1 mm. The filling ratio averaged 0.54 (range: 0.36-0.75). Thirty patients (40.5%) displayed bone resorption, first seen at 16.6 months (range: 3-40 months), commonly in zones 1 and 5. A total of 22 patients had ≥1 zone with partial resorption, and 8 (10.8%) developed full thickness resorption after 32 (range: 10-49) months.One new finding was that female sex and older age accounted for 51% of the variation of the filling ratio. A high filling ratio, especially when >0.55, correlated with bone resorption (P < .001). Age, sex, and prosthesis type did not directly predict bone resorption. Bony sclerosis correlated with a high filling ratio (P = .019) and thereby indirectly with resorption. A direct correlation between sclerosis and resorption was narrowly insignificant (P = .058) once correcting for the filling ratio. Reverse shoulder prosthesis had a higher filling ratio than total shoulder prosthesis patients (P < .001), resulting indirectly in more bone resorption. The preoperative diagnosis did not significantly correlate with the filling ratio (P = .59) or the resorption score (P = .69). A varus or valgus alignment did not predict resorption (P = .21) or the formation of sclerotic lines (P = .93). Bone loss did not correlate with clinical results. These short stems are firmly anchored 2-5 years postoperatively. However, significant bone loss, linked to a high filling ratio (>0.55), is observed proximally around these stems. The development of sclerotic lines around the stem indicates oversizing. Other factors were not found to have a significant effect on stem ingrowth. The implantation of stems with a large filling ratio is more common in older females and in patients receiving reverse shoulder prosthesis. Autologous impaction bone grafting could downsize the required stem. If adequate hold is not afforded by a suitably small stem, cementation is advisable.

Medium-term rates of radiolucency after primary total shoulder arthroplasty using a cementless metal-backed pegged polyethylene glenoid.

Total shoulder arthroplasty is an established treatment with the commonest cause of failure loosening of the glenoid component. Hydroxyapatite metal-backed glenoid components could offer better survivorship due to improved fixation. The aim of this study was to investigate periprosthetic radiolucency rates associated with an uncemented, metal-backed polyethylene glenoid component with medium-term results. A single centre retrospective study examining radiological outcomes of the Epoca metal-backed glenoid component. Radiographs were analysed for post-operative adequacy of glenoid seating and radiographs at follow-up assessed for periprosthetic lucencies and any revision procedures were recorded. Forty-one patients were followed up with a mean follow-up time of 5.5 years (3-8 years). Primary indication for total shoulder arthroplasty was osteoarthritis (80%). Mean age was 69 years (53-86 years). Ninety-five per cent of glenoid components were completely seated. At follow-up six patients had undergone revision (14.6%). Thirty of the remaining patients (86%) did not demonstrate any radiolucency on follow-up radiographs. Complete glenoid seating post-operatively was associated with lower rate of subsequent radiolucency and revision (P < 0.01). Low rates of radiolucency at medium-term follow-up with an uncemented metal-backed glenoid, however significant rates of revision. Complete seating of the glenoid component was associated with lower rates of radiolucency and revision.

The Bologna-Oxford ankle replacement: a case series of clinical and radiological outcomes.

The Bologna-Oxford (BOX®) total ankle arthroplasty (TAA) is a three-component mobile-bearing implant gaining popularity in Europe. We aimed to analyse the outcomes of this TAA. We retrospectively analysed data on 34 consecutive BOX® TAAs performed at a single centre with a mean follow-up of 58months. Radiographic outcomes, such as periprosthetic lucency and alignment, were measured and recorded. Prospectively captured clinical scores and range of movement (ROM) were also recorded. There were significant improvements in patient-reported outcome scores recorded in the Manchester-Oxford Foot Questionnaire (MOxFQ) for pain (43.8 ± 20.2, p < 0.001), standing and walking (55.6 ± 19.8, p < 0.001), social activities (45.0 ± 26.9, p < 0.02) and visual analogue score (VAS) (3.1 ± 2.5, p < 0.001). Mean improvement in ROM postoperatively was 18.7° (p < 0.001), with post-operative dorsiflexion 8.8° (10°-25°) and plantar flexion 32.6° (20°-40°). There was evidence of asymptomatic lucency on five radiographs (15%), which was present in 10% at three years. Nine patients had complications (26%): six (18%) requiring secondary surgery and one requiring revision (3%) for infection. We have demonstrated 97% survivorship at a mean of 58months. There are maintained improvements in clinical and radiological outcomes and reoperation that are consistent with the literature.

Long-term results of an anatomically implanted hip arthroplasty with a short stem prosthesis (MiniHipTM).

AIMTo evaluate the clinical and radiological outcome nine and ten years after short-stemmed, bone preserving and anatomical hip arthroplasty with the MiniHipTM system.METHODSIn a prospective study, 186 patients underwent hip arthroplasty with a partial neck preserving short stem (MiniHipTM, Corin). Elderly patients were not excluded from this study, thus the mean age at the time of surgery was 59.3 years (range 32 to 82 years). Surgery and the follow-up assessments were performed at two Centers. Up until now, the mean follow-up was 112.5 ± 8.2 mo. The Oxford Hip Score (OHS) and the Hip Dysfunction Osteoarthritis and Outcome Score (HOOS) was assessed pre- and each year after surgery. The clinical follow-up was accompanied by standardized a.p. and axial radiological examinations. Periprosthetic lucencies, hypertrophies within the Gruen zones one to fourteen were assessed. A subsidence of the stem was investigated according to Morray and heterotopic ossifications were assessed according to Brooker.RESULTSThe OHS and HOOS improved from 18 ± 3.3 to 46 ± 2.0 and from 30 ± 8.3 to 95 ± 4.6 points, P < 0.001 respectively. There were no differences regarding age, etiology, friction pairings, etc., (P > 0.05). Two stems were revised due to a symptomatic subsidence four and twelve months postoperatively. Thus, the survivorship for aseptic loosening at nine to ten years was 98.66%. Including one stem revision due to a symptomatic exostosis, bursitis and thigh pain as well as one revision because of a septic stem loosening, the overall survival for the stem with revision for any reason was 97.32%. Besides one asymptomatic patient, radiological signs of a proximal stress-shielding, such as bone resorptions within the proximal Gruen zones, were not noticed. Findings suggesting a distal loading, e.g., bony hypertrophies or bone appositions of more than 2 mm, were also not detected.CONCLUSIONRegarding these first long-term results on the MiniHipTM, the implant performed exceedingly well with a high rate of survivorship for aseptic loosening. Our radiological results within the Gruen zones support the design rationale of the Minihip to provide a reliable metaphyseal anchoring with the expected proximal, more physiological load transfer. This might minimize or exclude a stress shielding which might be associated with thigh pain, proximal bone loss and an increased risk of aseptic loosening. The MiniHipTM is a reliable partial-neck retaining prosthesis with good a clinical long-term outcome in younger as well as elderly patients.

Short-term rates of radiolucency after primary total shoulder arthroplasty using a cementless metal-backed pegged polyethylene glenoid.

Total shoulder arthroplasty has shown good clinical efficacy in treating primary and secondary degenerative conditions of the glenohumeral joint. Glenoid loosening, however, remains the commonest cause of failure. The purpose of this study was to investigate the rate of radiographic periprosthetic lucency associated with the use of an uncemented, pegged, metal-backed polyethylene glenoid component. A retrospective, single-centre study using the Epoca (Synthes, Paoli, Pennsylvania) metal-backed glenoid component. Operations were performed by two experienced consultant upper limb surgeons. Radiographs were analysed for immediate post-operative component seating and periprosthetic radiolucent lines at predefined regular post-operative intervals. Intra- and inter-observer reliability was assessed to improve validity of results. Mean age and follow-up was 72 (48-91) years and 2.5 years (2-5), respectively. Main indications for total shoulder arthroplasty were primary osteoarthritis, rheumatoid arthritis, revision for failed hemi-arthroplasty and acute fracture. Ninety-six per cent of components were completely seated post-operatively. Fifty-four (95%) of the 57 shoulders had no periprosthetic radiolucent lines at most recent follow-up. Complete post-operative glenoid seating was significantly associated with the absence of later periprosthetic radiolucency (p < 0.01). This study reports low early radiolucency rates with the pegged, uncemented, metal-backed polyethylene glenoid prosthesis used. Excellent post-operative glenoid seating is associated with a significantly lower rate of radiolucency. Longer follow-up data are required to confirm these early promising results.Level of evidence: Therapeutic, level IV.

Mid- to Long-Term Results of Total Ankle Replacement in Patients with Hemophilic Arthropathy

Category: Ankle Arthritis Introduction/Purpose: Hemophilia is a rare hematological disease associated with spontaneous joint hemorrhaging causing hemophilic arthropathy. Symptoms comprise joint pain and deformity, paired with loss of function. In the presence of advanced joint deterioration, therapeutic options are confined to either arthroplasty or arthrodesis. For the ankle, the latter is still referred to as the procedure of choice. However - in light of its capacity to reduce pain while preserving ankle motion - total ankle replacement (TAR) has recently gained acceptance as an alternative. The aim of this study was to investigate the mid- to long-term results of TAR in hemophilic ankle arthropathy. Methods: Seventeen TARs were implanted between 1998 and 2012 (mean age: 43 years). Preoperative demographic and disease specific data, complications and revision surgeries were recorded. With a mean follow-up of 9.3 years (range, 2.2-17.8) implant survival was estimated using Kaplan-Meier analysis. Follow-up assessment of 12 TARs was performed after 9.6 years (5 lost to follow-up). Satisfaction and pain scales, the AOFAS hindfoot-score, and the SF-36 were obtained to assess clinical outcome. Radiographic evaluation of pre- and follow-up radiographs was conducted. Results: Three cases (17.6%) had undergone TAR removal secondary to loosening at an average interval of 7.5 years. The estimated implant survival was 94% at 5, 85% at 10, and 70% at 15 years (95% CI, 11.9-17.7). The mean estimated implant survival was 14.77 years (95% CI, 11.9-17.7). The mean level of satisfaction was 76%, and of pain 2/10 (VAS). ROM had increased significantly (p=0.037). The SF-36 summary scores were comparable to those of a matched standard population. The AOFAS hindfoot-score averaged 81/100 points. Conclusion: TAR is a viable treatment option for advanced hemophilic ankle arthropathy. Based on the herein presented follow- up, implant survival compares to that of non-hemophilic populations. Clinical mid- to long-term results are favorable. However, the majority of follow-up radiographs revealed component loosening and/or periprosthetic lucency. Considering the study population’s young age and specific risk factors, need for revision surgery secondary to symptomatic component loosening may arise.

Can Specific Implant Designs Implicate Variations in Outcomes of Total Ankle Arthroplasty? A Systematic Review

Category: Ankle Arthritis Introduction/Purpose: Some complications of total ankle arthroplasty could not be reduced by improvement of surgeon experience. The purposes of the study were to determine whether there were variations in term of (1) intraoperative complications, (2) postoperative complication, (3) reoperation, revision and failure, and (4) postoperative radiographic findings among different studies. Methods: A comprehensive search was conducted. There were 953 for initial review. Initially, 136 irrelevant records, 174 review articles, 46 case reports and 1 retracted paper were excluded. Of the remaining 596 papers, 23 ultimately met our inclusion for final review. Results: Intraoperative fractures rates were higher studies of BP-type. Most of the pain or stiffness, malalignments, impingements, cysts were occurred in studies of STAR, HINTEGRA, Agility and Salto. Polyethylene insert fractures were occurred in most studies of STAR. Ten reported postoperative osseous fractures which all resulted from patients used STAR and BP-type. Reoperation rates were higher in studies of STAR, BP-type, Agility and Salto. Arthrodesis rates were lower from HINTEGRA. Arthrodesis rates from STAR, BP-type and Salto were higher than their revision rates. Periprosthetic lucency rates were lower from studies of HINTEGRA. The lucency rates of tibia were higher than talus. Cyst could be more easily observed from studies of STAR, Agility and Salto. All the osteoarthritis were reported in studies of STAR, BP-type and Agility. Conclusion: Currently the complication rates of TAA significantly decrease with modern implants, surgeons experience and patients selection. Some design-specific features of different prostheses were found in our study which could implicate variations in the complications and radiographic findings. We believed that these result could further improve the implant design.