Postero-Central Slice Osteotomy of the Proximal Tibia: A Novel Technique for Correcting Resistant Tight Extension Gaps in Posterior-Stabilized Total Knee Arthroplasty for Varus Osteoarthritis.

BACKGROUND: The aim of total knee arthroplasty (TKA) is to circumvent the pain due to advanced osteoarthritis of the knee joint and correct the limb alignment and biomechanics to improve patients' quality of life. Apart from medio-lateral balancing, balancing flexion and extension gaps is a prerogative to achieve good results. This study proposes a novel surgical technique of postero-central slice osteotomy of the proximal tibia (PCSO-PT) for correcting tight extension gaps in posterior-stabilized knees and assesses its clinical and functional outcomes. METHODS: A prospective study was conducted on 84 consecutive knees with tricompartmental osteoarthritis and varus deformity, requiring PCSO-PT during posterior-stabilized TKA between January 2016 and July 2018. Knee Society scores, flexion deformity, range of motion, antero-posterior instability, and complications were assessed at regular intervals for a minimum of 2 years postoperatively. RESULTS: Residual flexion deformities less than 11° after posterior capsular release were successfully corrected by the osteotomy. The mean preoperative flexion deformity of 18.1 ± 2.5° improved to 8.6 ± 2.2° intraoperatively after posterior capsular release from the femoral end and to 0.65 ± 0.76° intraoperatively immediately after the osteotomy, with no residual flexion deformity noted in any patient 6 weeks postoperatively. It had no negative effect on the significant post-TKA improvement of the mean Knee Society score from 32 ± 12 preoperatively to 94 ± 3 at the terminal follow-up. A direct correlation between preoperative flexion deformity and a resistant, tight extension gap (P = 0.003) was noted. There was no increase in coronal plane or sagittal plane instabilities in midflexion or on mobilization throughout the follow-up period, nor were any major adverse effects noted in this period. CONCLUSIONS: A PCSO-PT is an effective and safe alternative to overcoming tight extension during TKA after femoral-end capsular release, instead of capsular release from the tibial end or midcapsular region. LEVEL OF EVIDENCE: Level IV, therapeutic study.

Lateral versus medial approach for total knee arthroplasty for valgus knee deformity shows comparable functional outcomes, hip-knee-ankle angle values, and complication rates: a meta-analysis of comparative studies.

INTRODUCTION: The aim of this meta-analysis of comparative studies was to update the current evidence on functional and radiographic outcomes and complications between medial and lateral approaches for total knee arthroplasty (TKA) for valgus knee deformity. MATERIALS AND METHODS: The PubMed, MEDLINE, Scopus, and the Cochrane Central databases were used to search keywords and a total of ten studies were included. The methodological quality of the included studies was assessed. Data extracted for quantitative analysis included the Knee Society score (KSS), range of motion (ROM), surgical time, hip-knee-ankle angle (HKA), and number and types of complications. Random- and fixed-effect models were used for the meta-analysis of pooled mean differences (MDs) and odds ratios (ORs). The Mantel-Haenszel method was adopted. RESULTS: A total of 1008 patients were identified, of whom 689 and 319 underwent TKA for valgus knee deformity with lateral and medial approach, respectively. The mean age was 70 ± 9.5 and 67.3 ± 9.6 years for the lateral and medial approaches, respectively. The mean follow-up was 37.8 ± 21.9 and 45.9 ± 26.7 months for the lateral and medial approach groups, respectively. Significantly higher functional outcomes were found for the medial approach, as measured by the postoperative KSS (MD = 1.8, 95% CI [0.48, 3.12], P = 0.007) and flexion ROM (MD = 3.12, 95% CI [0.45, 5.79], P = 0.02). However, both of these differences were lower than the minimal clinically important difference. Comparable surgical time and postoperative HKA angle values (MD = 0.22, 95% CI [- 0.30, 0.75], P = 0.40) between the two surgical approaches were found. The incidence of periprosthetic joint infections, fractures, transient peroneal nerve injuries, and deep vein thrombosis was comparable. CONCLUSION: This meta-analysis of comparative studies showed that when lateral and medial approaches are used for total knee arthroplasty for valgus knee deformity, comparable functional outcomes in terms of the KSS and ROM, surgical time, and postoperative hip-knee-ankle angle values can be expected. Similar rates of periprosthetic joint infection, fracture, and peroneal nerve injury were also found. LEVEL OF EVIDENCE: I. PROSPERO REGISTRATION NUMBER ID: CRD42023392807.

Predictors of outcome following two-stage revision total knee arthroplasty.

PURPOSE: Two stage revision arthroplasty remains the gold standard for peri-prosthetic joint infections of the knee. However, the functional outcomes of revision surgeries and the factors governing them require further investigation. The purpose of this study was to (a) evaluate impact of early and late stage I surgery and interval between stage I and stage II; (b) understand the impact of infecting organism and resistance; (c) to estimate long term survivorship and causes of failure. METHODS: A retrospective review of 86 patients, who underwent two stage revision for prosthetic joint infections of the knee, was performed. Time between onset of symptoms to stage I (T1), and T1 to re-implantation (T2), along with microbiological studies, were analysed for their impact on functional outcomes, failure modalities and survivorship. RESULTS: In this study, the mean KSS-Knee improved from 64.0 ± 10.0 pre-operatively to 76.9 ± 10.4, and 77.2 ± 10.1 at the 5 and 10 year follow up respectively. The KSS-Function improved from 44.4 ± 8.8 pre-operatively to 72.2 ± 9.5 and 79.8 ± 8.1 at 5 and 10 year follow-up respectively. This study also found that T1 and T2 remained critical factors in determining functional outcome and longevity of the implant and a delay in these intervals was a significant predictor of failure. Gram negative, poly-microbial infections and organisms with methicillin and vancomycin resistance demonstrated lower survivorship (p-value, 0.001 at 5, 10 and 12 years). Re-infections occurred in 4 cases while 9 cases failed due to aseptic causes. CONCLUSION: Two-stage revision arthroplasty produced good functional outcomes when the infection was caused by single sensitive organism that did not exhibit high resistance to antibiotics. Stage I performed within 4 weeks and the subsequent re-implantation procedure undertaken within 6 weeks demonstrated better outcomes.

Does design change in total knee arthroplasty implants affect patient-reported outcomes?

PURPOSE: The purpose of this study is to compare the early results of patient-reported outcomes between two generations of a total knee system. METHODS: Between June 2018 and April 2020, 121 first-generation, cemented TKAs (89 patients) and 123 s-generation, cemented TKAs (98 patients) were performed by a single surgeon. Demographic and surgical data were collected from all patients. Starting at the 6-month follow-up, patient-reported outcome measures Knee Injury and Osteoarthritis Outcome Score, Joint Reconstruction (KOOS-JR) and Knee Society (KS) clinical and radiographic scores were prospectively recorded. This study represents a retrospective review of these prospectively collected data. RESULTS: There were no statistically significant differences between the two groups in terms of demographic variables such as age, body mass index, gender and race. KOOS-JR and Knee Society (KS) scores improved significantly (p < 0.001) from their preoperative values in both device generations. There were no differences, pre-operatively, between the two groups in terms of KOOS-JR, KS functional, KS objective, patient satisfaction, and expectation scores; however, there were statistically significant (p < 0.001) lower values of KOOS-JR and KS functional scores for first versus second generation at 6 months (81 vs. 89 and 69 vs. 74, respectively). CONCLUSION: While significant improvement in KS objective, subjective, and patient satisfaction scores were noted with both knee systems, KOOS-JR and KS function scores were significantly higher at the early (6-month) follow-up in the second-generation group. Patients responded acutely to the design change as evidenced by significantly improved patient-reported outcome scores for the second generation.

Midvastus Versus Medial Parapatellar Approach in Simultaneous Bilateral Total Knee Arthroplasty.

BACKGROUND: The purpose of this study was to compare the postoperative outcomes over a period of 3 years in patients who underwent bilateral total knee arthroplasty (TKA) using midvastus (MV) versus medial parapatellar (MPP) approaches. METHODS: In this retrospective study, 2 propensity-matched cohorts of patients who underwent simultaneous bilateral TKA via MV (n = 100) and MPP (n = 100) approaches from January 2017 to December 2018 were compared. Surgical parameters compared were surgery time and the incidence of lateral retinacular release (LRR). Clinical parameters including the visual analog score for pain, time for straight leg raise (SLR), range of motion, the Knee Society Score, and the Feller patellar score were assessed in the early postoperative and follow-up periods up to 3 years. Radiographs were evaluated for alignment, patellar tilt, and displacement. RESULTS: LRR was performed on 17 knees (8.5%) in the MPP group and 4 knees (2%) in the MV group which was significant (P = .03). The time to SLR was significantly lower in the MV group. There was no statistically significant difference in the length of hospital stay between the groups. The visual analog score, range of motion, and Knee Society Score were better in the MV group within 1 month (P < .05), but no statistically significant differences were found later. Patellar scores, radiographic patellar tilt, and displacements were similar at all follow-up periods. CONCLUSION: In our study, the MV approach had faster SLR, less LRR, and better pain and function scores in the first few weeks after TKA. However, its effect on different patient outcomes has not been sustained at 1 month and further follow-up points. We recommend that surgeons use the surgical approach with which they are most familiar.

Clinical outcomes and survival comparison between NexGen all-poly and its metal-backed equivalent in total knee arthroplasty.

PURPOSE: This study aims to compare total knee replacement (TKA) with NexGen All-Poly (APT) and NexGen Metal-Backed (MBT) in terms of implant survivorship, reasons leading to implant failure and functional results of defined age categories. METHODS: A single-centre, retrospective evaluation of 812 patients who underwent knee replacement with NexGen CR between 2005 and 2021, comparing a modern congruent APT component to a modular MBT equivalent component using a similar surgical technique at a notable mean follow-up duration. Implant survival, functional outcomes using the Knee Society Score and range of motion were evaluated and compared in different age categories. RESULTS: Of the 812 NexGen CR TKAs performed at our institution, 410 (50.4%) used APT components and 402 (49.6%) MBT components. The survival rate of NexGen APT was 97.1% and that of NexGen MBT was 93.2% (p = 0.36). Removal of the implant occurred overall in 15 cases, for MBT in ten cases, and for APT in four cases. The FS was proved to be significantly higher when APT components were implanted in younger patients than for MBT (p = 0.005). A similar range of motion between the components was recorded (p = 0.1926). CONCLUSION: Under defined conditions, we measured the clinical results of implants from a single manufacturer implanted in a single department using a similar surgical technique. Considering the limitations, we suggest that all-polyethylene tibial components are equal or even superior to metal-backed ones across the examined age categories.

Do we still need to screen our patients?-Orthopaedic scoring based on motion tracking.

PURPOSE: Orthopaedic scores are essential for the clinical assessment of movement disorders but require an experienced clinician for the manual scoring. Wearable systems are taking root in the medical field and offer a possibility for the convenient collection of motion tracking data. The purpose of this work is to demonstrate the feasibility of automated orthopaedic scorings based on motion tracking data using the Harris Hip Score and the Knee Society Score as examples. METHODS: Seventy-eight patients received a clinical examination and an instrumental gait analysis after hip or knee arthroplasty. Seven hundred forty-four gait features were extracted from each patient's representative gait cycle. For each score, a hierarchical multiple regression analysis was conducted with a subsequent tenfold cross-validation. A data split of 70%/30% was applied for training/testing. RESULTS: Both scores can be reproduced with excellent coefficients of determination R2 for training, testing and cross-validation by applying regression models based on four to six features from instrumental gait analysis as well as the patient-reported parameter 'pain' as an offset factor. CONCLUSION: Computing established orthopaedic scores based on motion tracking data yields an automated evaluation of a joint function at the hip and knee which is suitable for direct clinical interpretation. In combination with novel technologies for wearable data collection, these computations can support healthcare staff with objective and telemedical applicable scorings for a large number of patients without the need for trained clinicians.

Failure modes in malrotated total knee replacement.

PURPOSE: Achieving normal rotational alignment of both components in total knee arthroplasty (TKA) is essential for improved knee survivorship and function. However, malrotation is a known complication resulting in higher revision rates. Understanding malrotation of the components and its concomitant clinical and functional outcomes are important for early diagnosis and management. The purpose of this study was to evaluate the effect of malrotation on clinical outcomes and failure modes in both single and combined rotational malalignment. METHODS: From our hospital database of 364 revisions, a cohort of 76 knees with patellar maltracking, stiffness, reduced range of motion and early aseptic failure were reviewed and investigated for component malrotation using computed tomography following Berger protocol. CT findings confirmed component malrotation in 70 of these patients. Investigations included (1) measurement of femoral component malrotation using surgical transepicondylar axis, (2) measurement of tibial component malrotation using anteroposterior axis and (3) measurement of combined component rotational errors. RESULTS: The correlation of CT analysis and clinical outcomes after primary TKA revealed association of patellar maltracking with femoral internal rotation, pain and instability with tibial internal rotation and knee stiffness in patients with combined component malrotation as the commonest mode of presentation. Our study showed that patients with isolated femoral, tibial and combined malrotation presented at a mean period of 3.4 ± 1.34, 1.7 ± 0.8 and 2.3 ± 0.69 years, respectively, after the index surgery. Post-revision, the mean Knee Society Score and Oxford Knee Score improved from 29.1 to 78.7, and 10.5 to 32.8, respectively, and the mean range of motion improved from 74.9 ± 24.8 to 97.1 ± 12.7 degrees at a mean follow-up of 42 months. CONCLUSION: Early detection of malrotation in TKA and its management with revision of both components can lead to better clinical and functional outcomes. LEVEL OF EVIDENCE: III.

Early- to Mid-Term Review of a Prospective, Multi-Center, International, Outcomes Study of an Anatomically Designed Implant with Posterior-Stabilized Bearing in Total Knee Arthroplasty.

Background and Objectives: National joint registries report higher total knee arthroplasty (TKA) revision rates in posterior-stabilized (PS) systems compared to non-posterior-stabilized designs. The purpose of this study was to investigate the implant survivorship and clinical outcomes of an anatomic implant with a PS bearing. Materials and Methods: An early- to mid-term follow-up of a prospective, multi-center, non-controlled outcomes study of patients who received primary TKA between November 2014 and June 2017 was performed. A total of 800 cases using PS bearings that were implanted in 664 patients were monitored post-operatively for their implant survivorship and adverse events for up to five years. The Knee Society Knee and Function scores, patient satisfaction, the five-dimensional European Quality of Life questionnaire, and range of motion (ROM) were evaluated pre-operatively and post-operatively at six weeks, six months, one year, two years, three years, and five years. Results: The mean follow-up period was 3.7 ± 1.3 years, and the three-year implant survival rate was 99.3% (95% CI: 98.4%, 99.7%) with five revisions during the five-year follow-up. Patient satisfaction was 96.1% at six weeks and increased to 99.3% at one year. All patient-reported outcome measures significantly (p < 0.0001) increased up to the one-year follow-up and then remained stable up to the five-year follow-up. Conclusions: This study supports the excellent survivorship and patient-reported outcomes of the Persona® Knee system using cemented, fixed bearing, posterior-stabilized components with minimal complications at early- to mid-term follow-up in an international Asian population. Ongoing observations are being performed to investigate the mid- to long-term survivorship and clinical outcomes associated with this knee system.

Primary constrained condylar knee arthroplasty in severe varus deformity: a prospective 5-year functional follow-up study in Iraqi patients.

PURPOSE: The outcomes of the constrained condylar knee (CCK) implant used during primary total knee arthroplasty (TKA) in knees with severe varus in patients from low- and middle-income countries (LMICs) such as Iraq are not known. Hence, this study aimed to analyze and report the functional outcome of CCK TKA in patients with severe varus deformities at the end of 5 years in Iraqi patients. METHODS: In this prospective study, pre- and post-operative (at the end of 5 years) clinical outcome using Knee Society Score (KSS) and radiological deformity using hip-knee-ankle (HKA) angle was analyzed in 76 CCK TKAs (20 bilateral and 36 unilateral TKAs) performed in 56 patients with severe varus deformity (> 15°). RESULTS: At a mean follow-up of 60.3 months (range 60-68 months), the mean preoperative KSS knee score of 6.6 ± 4.5 improved significantly (p < 0.0001) to 87.2 ± 6.6 and the mean preoperative KSS function score of 7.1 ± 6.4 improved significantly (p < 0.0001) to 70.4 ± 7.8. The function score was good to excellent in 64.3% (36 patients), fair in 28.5% (16 patients), and poor in 7.1% (4 patients) at the end of 5 years. The mean preoperative HKA angle significantly improved (p < 0.001) from 25.5° ± 6° varus (range 17°-37°) to 3° ± 2.5° varus (range 0°-7.5°) at final follow-up. CONCLUSION: The CCK implant significantly improved pain and function in patients with severe varus deformity at the end of 5 years. The CCK implant is a good option during primary TKA in severe varus knees in patients from LMICs and can help achieve clinical outcomes similar to patients from high-income countries.

All-polyethylene versus metal-backed tibial components in total knee arthroplasty: a meta-analysis of randomized controlled trials.

OBJECTIVES: The design of tibial trays for total knee arthroplasty (TKA) has been a topic of research for several decades. Although all-polyethylene trays were developed to address issues such as osteolysis and to enhance the longevity of the prosthesis, as well as knee range of motion, metal-backed designs have remained the most commonly used type of prosthesis. This meta-analysis aimed to compare the clinical, radiological, and survival outcomes of both designs. METHODS: Five databases were searched from inception until October 1, 2020, for randomized controlled trials (RCTs) that compared the outcomes of all-polyethylene and metal-backed tibial components in TKA. The outcomes of interest included range of motion, knee society score, stairs climbing scores, radiostereographic analysis, survivorship and complication. This review was conducted in line with PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Risk of bias was assessed using the Newcastle-Ottawa tool. RESULTS: A total of 14 RCTs with 1367 TKA were included with a mean age of - years and - years for all-polyethylene and metal-backed tibial components groups, respectively. All-polyethylene group demonstrated statistically significant differences in five-year survivorship (OR 0.27; 95% CI 0.10-0.75; p value 0.01) and stairs climbing score (OR - 2.07; 95% CI - 3.27-0.87; p value 0.0007) when compared to the metal-backed group. The metal-backed design was significantly more radiographically stable in anterior-posterior, varus-valgus, and internal-external rotations at the 2-year follow-up compared to all-polyethylene tibias (OR - 0.09; 95% CI - 0.16 to - 0.02; p value 0.02) as per the pooled radiostereographic analysis. However, ten-year survivorship (OR 0.92; 95% CI 0.53-1.60; p value 0.78), range of motion (OR - 0.57; 95% CI - 2.00-0.85, p value 0.43), knee society scores (OR 1.38; 95% CI - 0.47-3.23, p value 0.14), and complications (OR 0.83; 95% CI 0.5-1.39, p value 0.48) were comparable between both groups. CONCLUSIONS: While this meta-analysis suggests that all-polyethylene tibial components in total knee arthroplasty may offer advantages over metal-backed components in terms of five-year survivorship, and stairs climbing score, this finding should be considered in the context of potential confounding factors. Nonetheless, based on the results, the all-polyethylene implant should be considered a viable choice for primary knee replacement. LEVEL OF EVIDENCE: I.

The role of posterior condylar offset ratio on clinical and functional outcome of posterior stabilized total knee arthroplasty: a retrospective cohort study.

BACKGROUND: Postoperative Range of Motion (ROM) is an important measurement of the success of a Total Knee Arthroplasty (TKA). Much enthusiasm has been recently directed toward the posterior femoral condylar offset (PFCO), with some authors reporting increasing postoperative knee flexion when increasing PFCO. The aim of this study is to retrospectively determine the effect of the PFCO on the clinical and functional outcome of a cohort of patients who underwent a Posterior Stabilized (PS) TKA. METHODS: Clinical and radiological data of all patients who underwent TKA with PS implant for primary osteoarthritis were retrospectively reviewed. Knee Society Score (KSS), knee ROM, PFCO ratio (PFCOR), and tibial slope (TS) were measured pre and postoperatively. RESULTS: One hundred and twenty-one patients (141 knees) met the inclusion criteria. The mean knee flexion increased from 98 ± 20.2° (range 30-130) to 123 ± 12.1° (range 70-140) and the mean KSS increased from 74.0 ± 3.3 (range 27-130) to 203.9 ± 8.1 (range 26-249). Postoperative PFCOR and TS were 0.492 ± 0.005 (range 0.40-0.57) and 2.36 ± 0.56° (range - 10.9-12.15°), respectively. Neither maximal flexion angle nor KSS showed a significant correlation with postoperative PFCOR (Pearsons'r = - 0.057, p = 0.5 for flexion angle and Pearsons'r = - 0.073, p = 0.5 for KSS) or with postoperative TS (Pearsons'r = 0.042, p = 0.62 for flexion angle and Pearsons'r = 0.002, p = 0.98 for KSS). CONCLUSION: Posterior femoral condylar offset remains an important parameter and, especially when using anterior femoral referencing TKA, care must be taken to prevent excessive resection of the posterior femoral condyles.

Increased posterior translation but similar clinical outcomes using ultracongruent instead of posterior stabilized total knee arthroplasties in a prospective randomized trial.

PURPOSE: The aim of this study was to compare the posterior tibial translation after ultracongruent (UC) and posterior-stabilized (PS) total knee arthroplasty (TKA) with two different UC with different heights in the anterior lip, and two different PS designs. This study also aimed to compare the range of motion (ROM) and outcomes scores after the use of these TKA models. It was hypothesised less posterior tibial translation after PS than after UC TKA, and less posterior tibial translation with a higher anterior lip in the UC insert than with a lower one. METHODS: It was designed as a prospective randomized study of a group of 120 patients operated with a cemented TKA. To clarify the main purpose of the study, four groups were analysed using different polyethylene designs: Triathlon PS insert in group one, Triathlon UC insert in group two, U2 PS insert in group three and U2 UC insert in group four. One year after surgery, a forced posterior drawer with a Telos Stress applying 15 kg of force posteriorly on the proximal tibia at 90° of knee flexion was analysed in the lateral radiograph. Limb alignment, tibial posterior slope and posterior condylar offset were also studied. RESULTS: 30 patients were included in each group. The average age was 73 years. There were 72.2% female and 27.8% male patients. There were no significant differences in any demographic or radiographic studied variables, preoperative range of motion (ROM) or preoperative Knee Society Scores (KSS) among the different groups. One year after surgery, the average postoperative ROM and the postoperative KSS Knee and KSS Function scores improved in respect of the preoperative values in all the groups. There were no significant differences in the postoperative outcome scores among the different groups (p = n.s.). Postoperative alignment of the limb, tibial posterior slope and posterior condylar offset were similar in the 4 study groups (p = n.s.). The postoperative posterior tibial translation was different between groups: the PS groups (groups 1 and 3) showed significant inferior values (p < 0.001) in respect of the UC groups (groups 2 and 4). There were no differences between both groups of PS models, but there was a significant increase in the posterior tibial translation of the Triathlon UC insert (11.2 mm SD 3.2) in respect of the U2 UC insert (6.1 mm SD 4.5) (p = 0.004). CONCLUSIONS: UC inserts restrict the posterior tibial translation after TKA less than PS inserts, but a design with a high anterior lip in the polyethylene UC insert can better control the posterior tibial translation than an insert with a small anterior lip. LEVEL OF EVIDENCE: Level I. Randomised controlled trial.

A validated outcome categorization of the knee society score for total knee arthroplasty.

PURPOSE: To determine cutoff values for the Knee Society Scores (KSS) indicative of a categorical scale of medium-term outcomes. METHODS: One hundred and fifty-five patients who underwent primary cruciate-retaining TKA with a patellar button for osteoarthritis at a single-centre were assessed prospectively by the KSS and short-form Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) simultaneously at the 3-year follow-up. A validated categorization of the WOMAC score was used as a standard. The area under the curve (AUC) of receiver-operating characteristic (ROC) was used to assess the discriminative analysis accuracy of the, and the Youden index estimated the optimal cutoff point. RESULTS: For the KSS-knee score, the cutoff for an excellent outcome was 90.3 (AUC 0.75, 95% CI 0.71-0.78), 76.6 (AUC 76.6, 95% CI 0.70-076) for good, 64.8 (AUC 0.76, 95% CI 0.72-0.79) for fair, and < 64.8 (AUC 0.69, 95% CI 0.67-0.73) for poor. For the KSS-function score, the cutoff values were 85.2 (AUC 0.71, 95% CI 0.69-0.75), 73.1 (AUC 0.72, 95% CI, 0.70-0.76), 55.7 (AUC 0.70, 95% CI 0.71-0.74), and < 55.7 (AUC 0.68, 95% CI 0.66-0.72), respectively. CONCLUSION: A KSS-knee score ≥ of 90 was considered an excellent outcome, 77 good, 65 fair, and < 65 poor. For the KSS-function, those values are 85, 73, 56 and < 56, respectively. The treatment outcome's judgement may be clearer for the surgeon concerning a particular patient when using cutoff values for the scoring system employed, such as those determined in the present study. LEVEL OF EVIDENCE: II.

Clinical Outcomes Following Distal Femur Replacement for Periprosthetic Distal Femur Fractures: A Systematic Review and Meta-Analysis.

BACKGROUND: Management of periprosthetic distal femur fractures (PDFFs) is often complicated by poor bone quality and limited bone stock making fixation attempts challenging and prone to failure. Distal femoral replacement (DFR) is being used to treat such injuries although outcome data are mostly from small case series. We sought to systematically review the literature on DFR for PDFF to summarize their outcomes. METHODS: PubMed, MEDLINE (EBSCO), and Cochrane Central Database were searched to identify reports of PDFFs treated with DFR. Articles reporting on 5 or more knees were systematically reviewed for clinical function, complications, and mortality. Random effects meta-analysis was used to create summary estimates and publication bias also assessed. RESULTS: Of 287 identified and screened articles, 15 were included, 14 retrospective, reporting on 352 knees. Following DFR, 87% (95% confidence interval [CI] 71-95) of patients were able to ambulate. The mean postoperative Knee Society Score was 80 (95% CI 77-84). The risk of periprosthetic joint infection was 4.3% (95% CI 2.2-8.2). One-year postoperative mortality rate was 10% (95% CI 6-18). There was some evidence of publication bias with a trend toward smaller studies reporting lower infection risk and mortality. CONCLUSION: DFR for PDFFs is associated with high functional outcomes and a relatively modest risk of infection. The periprosthetic joint infection and 1-year mortality rates reported here should be considered lower bounds estimates due to publication bias and loss to follow-up. Further investigation of long-term outcomes following DFR for PDFFs is warranted though short-term functional outcomes are promising.

The AAHKS Clinical Research Award: Are Minimum Two-Year Patient-Reported Outcome Measures Necessary for Accurate Assessment of Patient Outcomes After Primary Total Knee Arthroplasty?

BACKGROUND: The two-year minimum follow-up after total knee arthroplasty (TKA) required by most academic journals is based on implant survivorship studies rather than patient-reported outcome measures (PROMs). Additionally, the COVID-19 pandemic placed an unprecedented burden on patients and staff and halted asymptomatic surveillance clinic visits to minimize exposure. The purpose of this study was to determine if clinically meaningful differences were observed in PROMs beyond one year after TKA. METHODS: A retrospective review was performed on prospectively collected PROMs after 1093 primary TKAs at a suburban academic center. PROMs related to pain, function, activity level, and satisfaction were compared by subsequent follow-up intervals preoperatively, at 4 months, 1 year, and minimum 2 years using paired data analysis techniques. RESULTS: Pain with level walking and while climbing stairs improved from preoperative levels to 4-month, 1-year, and minimum 2-year follow-up. The University of California Los Angeles activity level and Knee Injury and Osteoarthritis Outcome Score for Joint Replacement improved over the same intervals. Patient satisfaction improved over postoperative follow-up intervals (84.0%, 87.3%, and 90.9%). While PROMs improved with statistical and clinical significance preoperatively to 4-month to 1-year follow-up, improvements from 1-year to minimum 2-year follow-up were small and did not reach minimum clinically important differences for nearly all PROMs, demonstrating significant overlap of the 95% confidence intervals. CONCLUSION: While long-term follow-up after TKA remains important for implant survivorship, it appears that one-year PROMs are as clinically reliable and meaningful as two-year PROMs. Therefore, it is reasonable to question the currently accepted 2-year minimum follow-up requirement used in peer-reviewed research involving PROMs. LEVEL OF EVIDENCE: Level III.

Use of an Intramedullary Allogenic Fibular Strut Bone and Lateral Locking Plate for Distal Femoral Fracture with Supracondylar Comminution in Patients over 50 Years of Age.

Background and Objectives: Distal femoral fracture is a severe injury that makes surgery challenging, particularly comminuted fractures in the supracondylar region. This study aimed to evaluate the outcomes of distal femoral fracture treated with the application of an intramedullary fibular allogenic bone strut in open reduction and internal fixation (ORIF) with precontoured locking plates in patients over 50 years of age. Materials and Methods: The study retrospectively enrolled 202 patients over 50 years of age with traumatic comminuted distal femoral fracture (AO/OTA 33-A3, 33-C2 and 33-C3) treated with ORIF with a locking plate from January 2016 to December 2019. The two groups were divided into patients who received an intramedullary allogenic bone strut and those who did not. Patients were followed for at least 1 year, with their function scores and radiographic data recorded. Results: A total of 124 patients were recruited, comprising 60 men and 64 women with an average age of 62.4 ± 8.5 years. The 36 patients who had received an intramedullary allogenic fibular bone strut reported lower postoperative pain scores at 1 month and lower postoperative Knee Society Scores (KSS) at 3 months than the control group. The application of an intramedullary allogenic fibular bone strut appeared to be significantly correlated with better 3-month postoperative KSS. Conclusions: The ORIF of distal femoral comminuted fracture with an intramedullary allogenic fibular bone strut can reduce pain and improve knee function in the early stages of postoperative rehabilitation and may reduce the time to union in patients over 50 years of age.

Mid-term clinical outcomes and complications of primary total knee arthroplasty in hemodialysis patients: a retrospective comparative cohort study.

BACKGROUND: Numerous patients who receive hemodialysis (HD) undergo total knee arthroplasty (TKA) due to advanced knee joint arthritis. However, there are few studies that describe the clinical outcomes and complications of TKA in HD patients. This study investigated the mid-term results of TKA in patients undergoing HD. METHODS: This single-center retrospective study compared clinical and surgical outcomes following TKA in patients who were receiving HD with those who were not. We used propensity scores to match 21 knees of 18 patients who received HD to 706 knees of 569 patients who had not received HD, from a total of 727 knees (587 patients) that underwent primary unilateral TKA. The clinical outcomes were evaluated using the American Knee Society Score-knee (AKSS-knee) and AKSS-function scores. The primary surgical outcome measure was the number of knees with postoperative complications. RESULTS: In both the HD and non-HD groups, postoperative AKSS-knee and function scores significantly improved when compared to preoperative values. Postoperative AKSS-knee and function scores were not significantly different between the groups. The number of knees with postoperative complications was larger in the HD group than the non-HD group within the first postoperative month, 0-12 months, 12-24 months, 0-24 months, and two years after surgery. Additionally, in the HD group, more complications occurred in the first month than any subsequent month in the two years after surgery. CONCLUSIONS: TKA improves AKSS-knee and function scores equivalently for HD patients and non-HD patients. However, HD patients develop more complications after TKA, especially within the first month. Therefore, surgeons who perform TKA for HD patients should obtain informed consent after explaining the possible complications, and HD patients should be carefully observed following TKA.

Early post-operative oxford knee score and knee society score predict patient satisfaction 2 years after total knee arthroplasty.

BACKGROUND: There is poor correlation between functional outcomes and patient satisfaction following total knee arthroplasty (TKA). We asked if early post-operative scores at 6 months or the pre- to post-operative change in scores are predictive of patient satisfaction 2 years after TKA. METHODS: We conducted a retrospective review of prospectively collected registry data of 4359 TKAs performed at a single institution. At 6 months and 2 years, the Knee Society Score (KSS), Oxford Knee Score (OKS), and Short-Form 36 scores were assessed. A satisfaction questionnaire was also completed. Logistic regression was used to generate receiver-operating characteristic (ROC) curves to assess the ability of each scoring system in predicting satisfaction at 2 years. RESULTS: At 2 years, 91.1% of patients were satisfied. For the absolute post-operative OKS at 6 months, an AUC of 0.762 (95% CI 0.736-0.788) and a threshold of ≤ 21.5 points (or ≥ 38.5 points on the new scale) were obtained. For the KSS knee score, an AUC of 0.704 (95% CI 0.674-0.734) and a threshold of ≥ 80.5 points were identified. The OKS performed significantly better than the KSS knee score (p = 0.03) and the other post-operative scores (p < 0.001). When analysing the change in scores pre-operatively to 6 months, the AUC was < 0.7 for all scales. CONCLUSIONS: Early post-operative scores, specifically the OKS and KSS knee score, can predict patient satisfaction at 2 years after TKA with good accuracy. The threshold values offer surgeons an additional tool to identify patients at risk of dissatisfaction at 2 years, enabling them to intervene earlier to ensure good patient satisfaction. LEVEL OF EVIDENCE: III, retrospective cohort study.

Customised, individually made total knee arthroplasty shows promising 1-year clinical and patient reported outcomes.

INTRODUCTION: Customised individually made (CIM) implants for total knee arthroplasty (TKA) were introduced about 10 years ago. These implants aim to reduce the risk of prosthesis-related issues resulting from anthropometric differences between different knees. The purpose of this study was to analyse the short-term clinical outcome and patient reported outcome measures (PROMs) of a specific CIM implant, the ORIGIN® knee replacement system (Symbios, Yverdon-les-Bains, Switzerland), which was introduced in 2018. MATERIALS AND METHODS: This is a prospective cohort study of patients undergoing primary posterior-stabilised (PS) CIM TKA using the specific ORIGIN® knee replacement system, (Symbios, Yverdon-les-Bains, Switzerland). TKAs were performed from February 2019 to October 2020. Data was collected preoperatively and postoperatively at 4 and 12 months. Outcome measures included the objective part of the Knee Society Score (KSS) with the range of motion (ROM) and the following PROMs: the Knee injury and Osteoarthritis Outcome Score (KOOS), the Forgotten Joint Score (FJS-12), the EuroQol, five dimensions, three levels (EQ-5D-3L) with the EuroQol visual analogue scale (EQ-VAS) and patient satisfaction. Differences in pre- to preoperative data were assessed with paired sample t tests. A p value < 0.05 was considered significant. RESULTS: Twenty-five CIM TKA (20 patients, 8 female) were included. The mean age at surgery was 66 years (SD, 6.9). At 4 and 12 months, significant improvements in the KSS (p < 0.001), the ROM (p < 0.001), all KOOS subscales (p < 0.001), the FJS (p < 0.001) and the EQ-5D-3L (p < 0.026) were found. Satisfaction rate was 91% and 88% at 4 and 12 months, respectively. Intraoperative complications did not occur and no revision surgeries were undertaken. CONCLUSIONS: The present study demonstrated significant improvements in the KSS and specific PROMs 1 year after CIM TKA. This study suggests that CIM TKA is a safe and suitable option, which can yield good clinical outcome and PROMs at least during short-term follow-up.