Knee Society Roentgenographic Evaluation Research Articles

Functional and radiological outcomes of total knee arthroplasty using posterior-stabilized U2 knee system: A retrospective study in 560 cases at five years of follow-up.

The purpose of this study was to assess clinical and functional outcomes as well as the prosthesis survival rates of the U2 Knee system in primary total knee arthroplasty (TKA) with a minimum follow-up of four years. We retrospectively analyzed 560 consecutively primary TKA performed between 2015 and 2019 due to osteoarthritis with a mean follow-up of 5.4 ± 1.1years. The clinical outcomes were assessed using the knee society score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). Radiographic outcomes were assessed using the American knee society's roentgenographic evaluation system. Prosthetic survival was calculated using the Kaplan-Meier method. Postoperative KSS showed significant improvement at one year (Clinical: 37.4 ± 4.1 vs. 91.9 ± 3.7; p < 0.01; Functional: 41.2 ± 3.3 vs. 90.6 ± 4.8; p = < 0.01), with these improvements maintained throughout the follow-up period. The WOMAC score improved from 60 ± 10.1 preoperatively to 10.9 ± 8.3 (p = 0.02) at the end of the follow-up. There were 20 (3.7%) knees with radiolucent lines around the implant (< 2mm), and none showed evidence of loosening. There were six (1.1%) revisions-four due to prosthetic joint infections and two due to periprosthetic femur fracture. The prosthetic survival was 97.8% at the study closure. The U2 knee system demonstrates effective and safe performance for primary TKA with significant improvements in functional scores, patient-reported outcomes, and a promising prosthesis survival rate at mid-term follow-up. We will continue with the series analysis to assess the long-term outcomes.

[Artículo traducido] Aparición temprana de líneas radiolúcidas alrededor de la artroplastia total de rodilla en pacientes con artritis reumatoide. ¿Cuál es su impacto en la tasa de fracaso aséptico y los resultados funcionales a los 13 años de seguimiento?

IntroductionAseptic total knee arthroplasty (TKA) failure has been associated with radiolucent lines. This study aimed to determine the impact of the early appearance of radiolucent lines (linear images of 1, 2, or > 2mm at the cement–bone interface) around the TKA on prosthetic survival and functional outcomes in rheumatoid arthritis (RA) patients during a 2–20 years follow-up. MethodsWe retrospectively analyzed a consecutive series of RA patients treated with TKA between 2000 and 2011. We comparatively analyzed patients with and without radiolucent lines around implants. Clinical outcomes were assessed with the knee society score (KSS) collected before surgery, at years 2, 5, and 10, and at the last postoperative follow-up. The knee society roentgenographic evaluation system was used to analyze the impact of radiolucent lines around the implants at 1, 2, 5, and more than ten years of follow-up. The reoperation and prosthetic survival rates were calculated at the end of the follow-up. ResultsThe study series included 72 TKAs with a median follow-up of 13.2 years (range: 4.0–21.0), of which 16 (22.2%) had radiolucent lines. We did not observe aseptic failure, and prosthetic survival at the end of the study was 94.4% (n=68). The KSS improved significantly (p<0.001) between preoperative values at 2, 5, and 10 years and the end of follow-up, with no differences between patients with and without radiolucent lines. ConclusionsOur study demonstrates that the early appearance of radiolucent lines around a TKA in RA patients does not significantly impact prosthetic survival or long-term functional outcomes at 13 years of follow-up.

Comparison of ultra-congruent anterior-stabilized vs. a posterior cruciate substituting total knee arthroplasty for osteoarthritis with severe varus knee deformity: comparable 2 year outcomes with two design.

In this retrospective study, we compared the functionality and clinical outcomes of patients with severe varus knees who underwent total knee arthroplasty (TKA) that used prostheses with either a posterior stabilized (PS) design or an ultra-congruent (UC) design. Primary TKA was performed in 161 patients; the UC device was used in 82 (51%) cases and the PS device in 79 (49%). Preoperatively and at the final follow-up examination, all patients were evaluated by orthoroentgenography. The mechanical axis angle and radiolucent lines were evaluated according to the Knee Society Roentgenographic Evaluation System on preoperative and 5-year follow-up radiographs. Total Knee Society Score (KSS) (knee score/function score) and Visual Analog Scale scores were obtained at the final follow-up examination. Demographic and surgical data and revision rates were evaluated for all patients. Postoperative angle values were significantly decreased in both the UC and PS groups (p<0.001 and p<0.001, respectively). Postoperative flexion range of motion values were significantly increased in both the UC and PS groups (p<0.001 and p<0.001, respectively). The postoperative KSS function scores were not significantly different between the groups (p=0.194). The mean surgical time of the PS group (54.99±4.18 minutes) was significantly higher than that of the UC group (46.02±4.48 minutes) (p<0.001). No notable differences were found between the UC and PS groups with respect to the clinical and functional parameters examined. Based on these results, UC TKA can be considered a safe alternative to PS TKA in severe varus knees.

Early appearance of radiolucent lines around total knee arthroplasty in rheumatoid arthritis patients. How does it impact the aseptic failure rate and functional outcomes at 13 years of follow-up?

IntroductionAseptic total knee arthroplasty (TKA) failure has been associated with radiolucent lines. This study aimed to determine the impact of the early appearance of radiolucent lines (linear images of 1, 2, or >2mm at the cement–bone interface) around the TKA on prosthetic survival and functional outcomes in rheumatoid arthritis (RA) patients during a 2–20 years follow-up. MethodsWe retrospectively analyzed a consecutive series of RA patients treated with TKA between 2000 and 2011. We comparatively analyzed patients with and without radiolucent lines around implants. Clinical outcomes were assessed with the knee society score (KSS) collected before surgery, at years 2, 5, and 10, and at the last postoperative follow-up. The knee society roentgenographic evaluation system was used to analyze the impact of radiolucent lines around the implants at 1, 2, 5, and more than ten years of follow-up. The reoperation and prosthetic survival rates were calculated at the end of the follow-up. ResultsThe study series included 72 TKAs with a median follow-up of 13.2 years (range: 4.0–21.0), of which 16 (22.2%) had radiolucent lines. We did not observe aseptic failure, and prosthetic survival at the end of the study was 94.4% (n=68). The KSS improved significantly (p<0.001) between preoperative values at 2, 5, and 10 years and the end of follow-up, with no differences between patients with and without radiolucent lines. ConclusionsOur study demonstrates that the early appearance of radiolucent lines around a TKA in RA patients does not significantly impact prosthetic survival or long-term functional outcomes at 13 years of follow-up.

Primary TKA in patients with major deformities and ligament laxities: promising results of an intermediate constrained implant at mid-term follow-up.

Total knee arthroplasty (TKA) in major deformities with ligament insufficiency may require a higher constraint, with bone sacrifice and concerns about long-term survivorship. Mid-level constraint liners have been recently introduced, but few studies described their outcomes. The aim of this study is to evaluate the short to mid-term outcomes of a constrained postero-stabilized (CPS) insert for primary TKA in moderate to severe deformities. All patients who underwent TKA using a CPS liner in two centers between 2015 and 2017 were included in the study. The indications were: (1) valgus deformity type 2-3 partially correctable; (2) severe varus deformity with varus thrust; (3) post-traumatic deformity with major ligamentous insufficiency and any case of intra-operative ligament insufficiency. Patients were evaluated according to the Knee Society Scoring System (KSS), the Hospital for Special Surgeryscore (HSS), the Western Ontario and Mc Master University (WOMAC) and the Oxford Knee score (OKS). X-rays were evaluated according to the Knee Society Roentgenographic Evaluation System. Forty-seven TKA were included, with an average age of 66.1 ± 10.3years and an average follow-up of 68.4 ± 6months. All patients demonstrated a moderate to severe pre-operative mediolateral instability. All the scores significantly improved (p < 0.0001). In 71.4% of cases, the outcomes were excellent or very good. There were no failures due to aseptic loosening but one failure due to a traumatic ligament rupture. The cumulative survivorship was 97.9% ± 2.1% at 84months. This mid-range constraint total knee replacement demonstrated promising outcomes and survival at mid-term follow-up. IV (case series).

Are cementation quality and clinical outcomes affected by the use of tourniquet in primary total knee arthroplasty?

Total knee arthroplasty is used to treat end-stage knee osteoarthritis with great results. Tourniquet use has become popular over the years because of its various benefits, but the literature regarding functional outcomes, pain and rehabilitation and comparison between tourniquet use and improvement cement penetration and overall improve fixation is limited. The authors proposed a hypothesis thatcementation quality, and clinical outcomes can be influenced by tourniquet technique. Fifty patients were allocated randomly in two groups: (1) tourniquet was inflated throughout all the procedure and (2) only during skin incision and cementation. Radiolucent lines were analyzed by two and independent examiners, using the The Knee Society Roentgenographic Evaluation and Scoring System. The functional scores used were the Oxford knee score and improvement in visual pain scale (VAS). After a mean follow-up period of 2.4 ± 0.2years, no difference was observed regarding partial use of tourniquet in the cementation quality (p value > 0.05). There was no difference between groups regarding gender, age, knee side, Visual VAS, Oxford Score, total range-of-motion (ROM), knee extension and knee flexion (p value > 0.05). No difference was attained regarding functional outcomes and cementation quality regarding two different tourniquet protocols.

Early results with a bicruciate-retaining total knee arthroplasty: a match-paired study.

The aim of this study is to compare 2 groups of total knee arthroplasties (TKAs): the bicruciate-retaining (BCR-group) and cruciate-retaining total knee arthroplasty (CR-group), evaluating the functional results in the short-term follow-up. 24 BCR were included in the study and were compared with a group of 24 TKAs performed with the same implant, but with sacrifice of the ACL and retention of the posterior cruciate ligament. For preoperative and postoperative clinical evaluation, the visual analogue score (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) were used. Radiological evaluation included weight-bearing long-leg view, a Rosemberg view, lateral view of the knee and tangential view of the patella. Hip-knee-ankle angle (HKA) was recorded pre and postoperatively. Radiolucent lines (RLLs) were evaluated according the Knee Society Roentgenographic Evaluation System (KSRES). At last follow-up the mean VAS score was 1.81 for BCR group and 1.43 for CR group (p = 0.61). The mean WOMAC score was 8.68 for BCR group and 12.81 for CR group (p = 0.33). As for the radiological evaluation, preoperative HKA angle was 0.53° varus for BCR group and 3.14° varus for CR group (p = 0.24); postoperative HKA was 0.72° valgus for BCR group and 0.38° valgus for CR group (p = 0.75). The percentage of RLLs was similar between the two groups (12% versus 15%). BCR-TKA has showed to give similar functional and radiographic outcomes compared to conventional CR-TKA in a similar cohort of patients. An higher operative times and higher number of complications respect were found in BCR group. These results can be explained by the early learning curve experiences. Future randomized controlled trials should be performed to support new implant designs such as BCR. Level of evidence Case-control study, level III.

The High Flex Total Knee Arthroplasty\u2014Higher Incidence of Aseptic Loosening and No Benefit in Comparison to Conventional Total Knee Arthroplasty: Minimum 16-Years Follow-Up Results

PurposeThis prospective randomized study compares the clinical and radiographic long-term results at least 16 years after total knee arthroplasty (TKA) between a mobile-bearing high flex and a fixed-bearing posterior-stabilized knee.MethodsIn 2000, we included 60 patients who underwent a TKA. Patients were divided into two groups. At the time of the follow-up after a minimum of 16 years (16.5 years ± 0.6), 16 patients had died for causes unrelated to the operation, 15 were lost to the follow-up. Five patients of the high flex group had a revision. The final evaluation included the hospital for special surgery score (HSS) and radiographs. Using the X-rays and the Knee Society Roentgenographic Evaluation and Scoring System, radiolucent lines and the maximal knee flexion were determined.ResultsNo significant differences between the two groups were found. The mean HSS score of LPS group patients was 87.9 (± 10.6) points and that of the high flex group was 93.1 (± 7.4) points. Five patients of the high flex group had undergone a reoperation. One knee was revised for painful mid-flexion instability and the others for symptomatic aseptic loosening of the components.ConclusionThe long-term follow-up does not show any clear benefits and even a higher incidence of implant loosening using the mobile-bearing high-flex knee.

Clinical and radiological outcomes of total joint arthroplasty in patients with ochronotic arthropathy.

Alkaptonuria is a rare metabolic disorder, and only a few case reports of total joint arthroplasty (TJA) for ochronotic arthropathy are described in the literature. We aim to analyse the functional and radiological outcomes of TJA in patients with ochronotic arthropathy. We retrospectively collected the data of twenty-seven TJA in sixteen patients with ochronotic arthropathy from April 2007 to December 2017. We assessed the functional outcome through pre- and post-operative modified Harris hip score (HHS) and knee society score (KSS). The hip radiographs were analysed for migration and radiolucent zones, and the knee radiographs were assessed using knee society roentgenographic evaluation and scoring system. The mean follow-up was 39.4months (12-132months). Two patients died before the final follow-up. There was a statistically significant improvement in mean HHS from 17.8 preoperatively to 78 at the final follow-up (p < 0.001). Similarly, there was a significant improvement in mean KSS, following the surgery, from 27.2 preoperatively to 89.4 (p < 0.001). One patient developed deep infection, and another patient presented with aseptic loosening of the acetabular component after 7years. In the radiological evaluation at the final follow-up, signs of lysis or loosening were not noted in any of the other patients. End-stage arthritis in ochronotic arthropathy is not uncommon. These patients can have multiple joint involvements, and the need for multiple surgeries should be considered. TJA in ochronotic arthropathy leads to a significant improvement in the functional outcome compared with the preoperative disability.

Does the medial pivot knee improve the clinical and radiographic outcome of total knee arthroplasty? A single centre study on two hundred and ninety seven patients.

Total knee arthroplasty (TKA) is a cost-effective surgery with a survival rate higher than 90% after 15years. Nevertheless, patients are unsatisfied in more than 15% of cases. Medial pivot (MP) prosthetic designs were introduced in late 90's with the aim to reproduce natural knee kinematics. The purpose of this study is to evaluate the survivorship and clinical outcomes of a novel design of MP knee with a minimum follow-up of fiveyears. This is a retrospective review of all patients who underwent primary TKA using the K-Mod dynamic congruence implant (Gruppo Bioimpianti, Peschiera Borromeo, Milan, Italy) between 2012 and 2013 at a single institution. A total of 339 patients (351 knees) were included with a mean age of 74years (range 41-89). The Knee Society score, the global range of movement, the Western Ontario and McMaster Universities Osteoarthritis score, Forgotten Joint score, and the short-term form 12 health survey were collected. FJS and SF-12 were collected only post-operatively. Radiographic outcomes were evaluated according to the Knee Society's roentgenographic evaluation system. Kaplan-Meyer (KM) curves were performed to evaluate implant survivorship. A two-tailed paired t test was performed to evaluate the differences between pre-operative and post-operative score. A total 297 patients (315 knees) were available for clinical and radiographic analysis, and the mean follow-up was 66.4months. A total of 17 patients (17 knees 5.4%) experienced a post-operative complication, and a reoperation was performed in five patients (5 knees 1.6%). Four patients had a periprosthetic joint infection, and two patients had a post-traumatic periprosthetic femoral fracture. The KM survivorship at fiveyears was 98.2% (95% CI 0.96 to 0.99) for revision for any reason. There was a statistically significant improvement (p < 0.05) in all the objective and subjective outcomes measured. The K-Mod dynamic congruence design has shown an excellent clinical, radiographic, and patient-reported outcome in primary TKAs.

Revision total knee arthroplasty (TKA): mid-term outcomes and bone loss/quality evaluation and treatment

BackgroundRevision total knee arthroplasty (rTKA) is a demanding procedure, with a high complication and failure rate and a high rate of bone losses and poor bone quality. Different classifications for bone losses have been proposed, but they do not consider bone quality, which may affect implant fixation. The aim of this study is to describe the outcomes of a consecutive series of rTKA. Furthermore, a modified bone loss classification will be proposed based also on bone quality. Finally, the association between radiolucent line (RLL) development and different risk factors will be evaluated.MethodsAll the patients who underwent rTKA between 2008 and 2016 in the same institution were included. rTKAs were performed by the same surgeon according to the three-step technique. Bone losses were classified according to the proposed classification, including bone quality evaluation. The Knee Scoring System (KSS), the Hospital for Special Surgery Knee Score (HSS), and the SF-12 were used for the clinical evaluation. Radiological evaluation was performed according to the Knee Society Roentgenographic Evaluation System. Different possible risk factors (i.e., gender, age, amount of bone losses) associated to RLL development were identified, and this association was evaluated using logistic regression.ResultsFifty-one patients (53 knees) were included (60.8% female, average age 71.5 years). The average follow-up was 56.6 months (range 24–182). The most frequent cause of failure was aseptic loosening (41.5%). 18.9% of the cases demonstrated poor bone quality. Bone losses were treated according to the proposed algorithm. In all the cases, there was a significant improvement in all the scores (P < 0.05). The average post-operative range of motion was 110.5° (SD 10.7). At the radiological evaluation, all the implants resulted well aligned, with 15.1% of non-progressive RLL. There were 2 failures, with a cumulative survivorship of 92.1% at the last follow-up (SD 5.3%). At the logistic regression, none of the evaluated variables resulted associated to RLL development.ConclusionrTKA is a demanding procedure, and adequate treatment of bone losses is mandatory to achieve good results. However, also bone quality should be taken into consideration when approaching bone losses, and the proposed classification may need surgeons after an adequate validation.Level of evidenceLevel IV

Medium-term follow-up of 149 mobile-bearing total knee arthroplasties and evaluation of prognostic factors influencing outcomes.

To evaluate the medium-term outcomes of a posterior-stabilized mobile-bearing total knee arthroplasty (PS-MB-TKA) and the role of different prognostic factors. Patients indicated for a primary cemented PS-MB-TKA between 2002 and 2010 were included and prospectively evaluated using the Knee Society Scoring System (KSS) and the Hospital for Special Surgery (HSS) knee scores. The Knee Society Roentgenographic Evaluation form was used for the radiological evaluation. Different variables were collected and divided into patient- and surgery-related. Logistic regression was used to analyze the correlation between these variables and implants outcomes and survivorship. In total, 149 cases were included (67.8% female, average age 70.4 years, SD ±9.4). The patella was resurfaced in 12.1% of the cases. All the implants were cemented. The average follow-up was 87.3 months (SD ±21.2). Postoperatively, there was a statistically significant improvement in all the scores. The cumulative survival was 96.2% (SD ±0.02%). At the regression analysis, female gender was associated to worse satisfaction KSS (OR = 0.26), functional KSS (OR = 0.22), and HSS (OR = 0.37) scores. Patellar resurfacing and subsequent contralateral procedures were associated to better functional KSS score (OR = 4.13, OR = 2.21), as well as varus preoperative alignment (OR = 2.12). On contrary, valgus preoperative alignment was associated to worse objective KSS score (OR = 0.23). No variables were correlated to failure or presence of radiolucent lines. Good medium-term outcomes were obtained using PS-MB-TKA, with a cumulative survivorship of 96.5%. Female gender and valgus preoperative alignment were associated to worse objective and subjective outcomes. Conversely, patellar replacement, subsequent contralateral TKA, and varus preoperative alignment were associated to better functional outcomes.

Short-to-Midterm Outcomes of Revision Total Knee Arthroplasty Patients With a Total Stabilizer Knee System

BackgroundRevision total knee arthroplasty (TKA) can often be challenging. The use of a new revision system may aid in providing better stability, improved function, fit, and implant longevity. Therefore, we assessed: (1) survivorship, (2) clinical outcomes, (3) postoperative complications, and (4) radiographic outcomes of patients who underwent revision TKA using this system. MethodsPatients from 2 hospitals who underwent revision TKA using a newer generation revision knee system between June 2008 and December 2013 for component instability or aseptic loosening were included. There were 93 patients, who had a mean age of 65 years (range, 41-84 years), and a mean follow-up of 4 years (range, 2-7 years). Survivorship was assessed using Kaplan-Meier analysis. Radiographic analysis was performed using the new Knee Society Roentgenographic Evaluation and Scoring System. ResultsAseptic survivorship was 96% (95% confidence interval, 6.6-7.3), and all-cause survivorship was 94% (95% confidence interval, 6.4-7.2). There were 2 infections and 4 aseptic loosening cases. The mean Knee Society score was 86 points (range, 38-100 points) and the mean functional Knee Society score was 52 points (range, 15-90 points) at final follow-up. The mean postoperative extension and flexion were 2° (range, 0°-20°) and 106° (range, 20°-130°), respectively. There were 3 medical and 11 surgical complications. Excluding the aseptic and septic failures, there were no progressive radiolucencies or osteolysis at final follow-up. ConclusionAt up to 7-year follow-up, this new revision system demonstrated excellent survivorship and good functional outcomes. Future studies should be prospective, comparative, and include larger cohorts for further assessment of this device.

Outcomes of Newer Generation Cementless Total Knee Arthroplasty: Beaded Periapatite-Coated vs Highly Porous Titanium-Coated Implants

BackgroundNewer generation cementless total knee arthroplasty (TKA) designs are available and have novel implant coatings. We evaluated and compared beaded periapatite (PA)-coated vs highly porous titanium-coated cementless TKAs. Specifically, we compared: (1) survivorship, (2) Knee Society Scores (KSSs) and range of motion, (3) complications, and (4) radiographic findings. MethodsThere were 805 TKAs with beaded PA-coated tibial and patellar components (PA group; mean age 67 years; range 41-86 years), and 219 TKAs with highly porous titanium-coated tibial and patella components (mean age 66 years; range 34-88 years). Mean follow-up was 4.4 years (range 2-9 years; median 4 years). Implant survivorship was calculated using Kaplan-Meier curves. Student t-tests and chi-square tests were used as appropriate. Radiographic evaluation was performed using Knee Society Roentgenographic Evaluation and Scoring System. ResultsAll-cause implant survivorship in beaded PA-coated group was 99.5% (95% CI, 97.9%-99.9%) and 99.5% (95% CI, 92.7%-99.9%) in highly porous titanium-coated group. There were no significant differences in the KSS for pain and function. Improvement in flexion and extension was similar in the 2 groups. Overall, complication rate (2.2% vs 2.3%; P = .274) and number of revisions (6 [0.8%] vs 2 [0.2%]; P = .936) were similar in the 2 groups. Excluding the aseptic and septic failures, there were no progressive radiolucencies or osteolysis on radiographic evaluation. ConclusionThis study has shown good clinical and patient-reported outcomes of cementless TKA for both implants. Future multicenter large scale clinical and cost-effectiveness studies are needed to determine the superiority of one cementless implant type over the other.

Postoperative Radiographic Assessment of the Vega Posterior-Stabilized TKA.

Different biomechanical designs are incorporated into various total knee arthroplasty (TKA) implants. The posterior-stabilized prosthesis design utilizes a polyethylene post and femoral cam in place of the posterior cruciate ligament. This produces a more stable component interface, increased range of motion, and potentially a less technical procedure. This study aimed to assess the short-term (>2 year) outcomes associated with the Vega System posterior-stabilized knee prosthesis (Aesculap Implant Systems, Center Valley, Pennsylvania) based on postoperative radiographs using the Knee Society Roentgenographic Evaluation and Scoring System (KSRESS). Thirty-seven TKA patients who had received the Vega posterior-stabilized knee prosthesis and had postoperative radiographs at each follow-up for a minimum of 2 years were enrolled, retrospectively. Two independent observers evaluated the radiographs using KSRESS. Descriptive statistics were used to analyze the data. The average age and body mass index of patients enrolled was 67 years (range, 51-89 years) and 38.5 kg/m(2) (range, 21.2-54 kg/m(2)), respectively. Patients had radiographic follow-up for an average of 36 months (range, 24-58 months). Comparison between first and last available postoperative radiographs revealed a stable femoral and tibial interface with no significant change in prosthesis alignment over the follow-up period. Assessment of the short-term survivorship of the Vega posterior-stabilized prosthesis using KSRESS revealed no significant change in alignment after 2 years of follow-up; however, mid- to long-term studies assessing this junction are needed. A future prospective study using KSRESS in combination with clinical follow-up is recommended to allow comparison of the Vega posterior-stabilized to other prostheses. [Orthopedics. 2016; 39(3):S56-S60.].

Mobile- versus fixed-bearing total knee arthroplasty: a prospective randomized controlled trial featuring 6-10-year follow-up.

The purpose of this study was to compare long-term clinical and radiographic outcomes of mobile- (MB) and fixed-bearing (FB) total knee arthroplasties (TKA). A randomized controlled study was conducted to compare the clinical and radiographic outcomes of MB and FB prostheses in 93 consecutive patients who underwent primary TKA for knee osteoarthritis. Mean follow-up of the patients was 100.9 months in the MB group (range: 78-121 months) and 93.7 months (range: 78-120 months) in the FB group. The clinical results were graded according to the Knee Society Knee Score (KSKS) and the Knee Society Functional Score (KSFS). Secondary outcomes included pain, patellofemoral joint function, quality of life (QOL), and radiologic outcomes (Knee Society's roentgenographic evaluation system). Although there was significant improvement in both groups, there were no significant differences between the groups with respect to mean KSFS and radiologic outcomes. However, mean pain score of the MB group was significantly higher than that of the FB group (48.83±0.62 vs 47.39±0.86, respectively, p=0.011), and mean KSKS was significantly higher than that of the FB group (93.5±6.2 vs 89.7±6.9, respectively, p=0.007). TKA clinical results were satisfactory in both the MB and FB groups. KSKS and pain scores were significantly better in the MB than in the FB group. However, no differences were found in other assessments. Thus, we conclude that the best design is the one with which the surgeon is most comfortable and most able to implant reproducibly.

Radiographic Evaluations of Revision Total Knee Arthroplasty: A Plea for Uniform Assessments

Thorough radiographic evaluation is necessary for perioperative assessments in revision total knee arthroplasty. There has been a large degree of variability in reporting these findings within the peer-reviewed literature. Our purpose was to evaluate studies that radiographically assessed alignment in the coronal and sagittal plane, patella alignment and thickness, presence and characterization of implant interface, and radiolucency. Secondly, we reviewed studies using a standardized reporting system to evaluate radiographic findings (the Knee Society Roentgenographic Evaluation and Scoring System) and the number of times it was referenced. Only 62% of studies evaluated all radiographic parameters, 57% to 91% assessed each metric, and 55% used standardized reporting systems. This emphasizes the need for a uniform evaluation method to ensure consistent radiographic assessment and optimal standard of care.

Primary modular total knee replacement in severe and unstable osteoarthritis. Predictive factors for failure.

Severe cases of osteoarthritis with ligamentous instability require the use of a modular knee arthoplasty. To assess the survival, the complications, the clinical, radiological and functional outcomes, and the quality of life of those patients in whom a Optetrak Condylar Constrained Knee (CCK) had been implanted as a primary implant. To study how the pre-operative conditions (deformity, age, sex …) and the characteristics of the arthroplasty (stems, supplements, constrained component …) could change the survival or the clinical outcomes of the implants. We performed an observational retrospective study of 105 CCKs implanted between 1999 and 2005. The mean follow-up was nine years (7, 13). Mean age was 70.5 years. The mortality was 6.9 %. There were 9.3 % of the patients lost during the follow-up. We studied all the medical files of the patients in order to assess the pre-operative, surgical and postoperative conditions. We used the Knee Society Score (KSS), both clinical and functional, to study the functional and clinical situation. We analysed the X-ray using the Knee Society roentgenographic evaluation. The quality of life was studied using the Oxford Knee Score (OKS). Then in order to find predictor conditions, we made statistical multivariable predictive studies attending to the preoperative factors and to the arthroplasty conditions to compare both outcomes and survival (Kaplan-Meier groups curves and Cox Multivariable Models [hazard ratio]). Processing and data analysis was performed using SPSS 15.0. The outcomes did not show differences between all the groups. While the mean result of the clinical KSS was 75.8, the mean functional KSS was 73.1. We did not find a condition associated with worst results of the knees (p > 0.05). The KSS obtained was excellent or good in 74.9 %. The global survival at 24 months was 93.8 % and at 96 months was 90.1 %. There were some conditions associated with poorest survival of the arthroplasties: patients younger than 70 years old, tibial tuberosity osteotomy, use of long stems and new surgery two months after arthoplasty (p < 0.05). The 11.1 % of the arthroplasties required more surgeries (3.3 % were soft tissue surgeries and 7.8 % were revisions). The mean OKS obtained was 34.78. Satisfaction was obtained by 86.2 % of the patients. All severe and unstable knees obtained similar and overall excellent-good outcomes and survival using the Optetrak CCK. Although we found that there are some factors that could change the survival of the total knee replacement, these did not change the outcomes.

Long term survivorship following Scorpio Total Knee Replacement

BackgroundThe Scorpio Total Knee Replacement (TKR) is one of the most commonly used prosthesis in the United Kingdom. Concerns arose at our institution that there was a high revision rate for this prosthesis. No study has assessed survivorship of this prosthesis over 10 years. MethodsFour hundred and fifty-six consecutive patients, who underwent a primary Scorpio TKR, were clinically and radiologically evaluated. WOMAC, Oxford Knee Score and all complications including the reason for revision surgery were recorded. The Knee Society Roentgenographic Evaluation and Scoring System was used to evaluate all radiographs for prosthesis alignment and degree of subsequent lucency. Survival analysis for the prosthesis was calculated using Kaplan–Meier curves, with revision as an end-point. Patient reported outcome measures were compared against radiographic evaluation. ResultsAt a mean of 12.5 years (range 10–14 years), 196 (43.0%) patients were available for review; 124 (27.2%) were lost to follow-up and 136 (29.8%) patients had died of unrelated causes. Seven (3.6%) patients required revision surgery at a mean of 5.4 years; five because of aseptic loosening and two because of septic loosening. Cumulative survival for the prosthesis was 99.5% for any cause at five years and 97.4% at 14 years. The mean OKS and WOMAC score at final follow-up was 30.64 (range12–48) and 74 (18.9–100) respectively. ConclusionThe Scorpio TKR has good long term survivorship and functional outcomes. There is no apparent increased revision rate for this prosthesis in our study. Level of evidenceLevel IV case series.

Short-Term Results of Total Knee Arthroplasty with Anterior-Posterior Glide LCS Mobile-Bearing System.

PurposeTo evaluate the clinical and radiological results of total knee arthroplasty (TKA) using the anterior-posterior glide (APG) low contact stress (LCS) mobile-bearing system.Materials and MethodsWe evaluated 130 knees in 117 patients who had undergone TKA with APG LCS mobile-bearing system between September 2005 and July 2007 and could be followed over 5 years. The mean follow-up period was 68 months. The clinical and radiological results were evaluated using the American Knee Society Scoring System, Oxford knee score and the American Knee Society Roentgenographic Evaluation and Scoring System. And we analyzed short-term postoperative complications.ResultsThe average range of motion of the knee joint was 107.9° (range, 70° to 135°) preoperatively and 125.2° (range, 90° to 135°) at the last follow-up. The average knee and functional scores were improved from 39.1 and 42.0 to 71.2 and 75.6, respectively, between the preoperative and last follow-up evaluation. The Oxford knee score was decreased from 42.9 preoperatively to 23.1 at the last follow-up. The femoro-tibial angle (anatomical axis) changed from 10.1° varus preoperatively to 3.3° valgus at the last follow-up. Radiolucency was observed in 14% of all cases. There were 1 case of traumatic dislocation of the polyethylene liner, 1 case of aseptic loosening and 6 cases of posterior instability because of posterior cruciate ligament (PCL) insufficiency.ConclusionsTKA with APG LCS mobile-bearing system demonstrated relatively good short-term clinical and radiological results. However, further considerations for posterior instability associated with PCL insufficiency are needed.