Comparable results in total knee arthroplasty using the ROSA knee system versus the conventional technique: A retrospective propensity-matched cohort study.

PURPOSE: Robotic-assisted total knee arthroplasty (RA-TKA) is an increasingly popular alternative that may increase the accuracy of conventional TKA techniques. This study aims to evaluate RA-TKA accuracy and compare its radiographic and clinical outcomes to conventional TKA (cTKA). METHODS: A retrospective examination of patients with bi- or tricompartmental knee osteoarthritis who underwent RA-TKA (RObotic Surgical Assistant system) or cTKA and were prospectively documented in the TKA registry. Accuracy was assessed using standardized radiographic implant position evaluations, namely femoral and tibial coronal angles and femoral and tibial sagittal angles. Baseline demographics, surgery details and 6- and 12-month post-TKA patient-reported outcomes (PROMs; e.g., Oxford Knee Score [OKS] and Core Outcome Measures Index) were compared between RA-TKA and propensity score-matched cTKA patients. RESULTS: Overall correlation between preset and 6-week postoperative angle measurements for RA-TKA was low with significant differences noted only for mean tibial sagittal angles (84.6° [RA-TKA] vs. 82.3° [cTKA]) (p < 0.001). The study groups were demographically similar, although RA-TKA patients had slightly longer operative times and higher blood loss but shorter inpatient stays. There were sustainable improvements in all PROMs already at 6 months, yet RA-TKA patients had significantly higher OKS values over their conventional counterparts at this time point. CONCLUSION: Radiological and clinical outcomes were comparable between RA-TKA and cTKA. The robotic-assisted system demonstrated higher accuracy in the coronal than sagittal plane and RA-TKA patients achieved better short-term outcomes for pain and disability. While both methods are similar in the hands of a skilled surgeon, long-term studies are necessary to establish clear method superiority. LEVEL OF EVIDENCE: Therapeutic, Level III.

Autologous minced cartilage repair for chondral and osteochondral lesions of the knee joint demonstrates good postoperative outcomes and low reoperation rates at minimum five-year follow-up.

PURPOSE: Minced cartilage is a one-step, autologous procedure with promising short-term results. The aim of the present study was to evaluate mid-term results in a patient cohort with chondral and osteochondral lesions in the knee joint treated with minced cartilage. METHODS: From 2015 through 2016, a total of 34 consecutive patients were treated with a single-step, autologous minced cartilage for knee chondral and osteochondral lesions. Numeric analogue scale (NAS) for pain and knee function were obtained prior to surgery and at 12, 24 and 60 months postoperatively. Secondary outcomes, including Lysholm score, Tegner activity score, and the International Knee Documentation Committee (IKDC) score, were recorded at final follow-up. MRI examinations of patients with unplanned radiological follow-up were analysed using the MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score. RESULTS: A total of 28 patients (44.1% females, age at surgery: 29.5 ± 11.5 years) were available at a mean follow-up of 65.5 ± 4.1 months. Mean defect size was 3.5 ± 1.8 cm2. NAS for pain decreased from a median of 7 (range: 2-10) preoperatively to 2 (0-8) postoperatively. NAS knee function improved from a median of 7 (range: 2-10) to 3 (0-7) after five years, respectively. Satisfactory Lysholm (76.5 ± 12.5), IKDC (71.6 ± 14.8) and Tegner activity (4, range 3-9) scores were reported at final follow-up. Of all patients, 21(75%) and 19 (67.9%) reached or exceeded the PASS for the IKDC- and Lysholm score at final follow-up, respectively. The average overall MOCART 2.0 scores for all postoperatively performed MRIs (n = 23) was 62.3 ± 17.4. Four (14.2%) postoperative complications were directly linked to minced cartilage, one (3.5%) of which required revision surgery. CONCLUSION: One-step, autologous minced cartilage repair of chondral and osteochondral lesions of the knee without the necessity for subchondral bone treatment demonstrated good patient-reported outcomes, low complication rates, and graft longevity at mid-term follow-up. Minced cartilage represents a viable treatment option to more traditional cartilage repair techniques even in mid-term. LEVEL OF EVIDENCE: Level III.

Biologic principles of minced cartilage implantation: a narrative review.

Cartilage tissue has a very limited ability to regenerate. Symptomatic cartilage lesions are currently treated by various cartilage repair techniques. Multiple treatment techniques have been proposed in the last 30 years. Nevertheless, no single technique is accepted as a gold standard. Minced cartilage implantation is a newer technique that has garnered increasing attention. This procedure is attractive because it is autologous, can be performed in a single surgery, and is therefore given it is cost-effective. This narrative review provides an overview of the biological potential of current cartilage regenerative repair techniques with a focus on the translational evidence of minced cartilage implantation.

Medial unicompartmental knee arthroplasty in ACL-deficient knees is a viable treatment option: in vivo kinematic evaluation using a moving fluoroscope.

PURPOSE: Unicompartmental knee arthroplasty (UKA), resulting in similar kinematics to native knees, is functionally superior to total knee arthroplasty (TKA). However, ACL deficiency is generally considered to be a contraindication. The main purpose of this study was to investigate if UKA in ACL-deficient knees would result in similar kinematics to conventional UKA with an intact ACL. METHODS: Ten conventional UKA patients were compared to eight ACL-deficient patients with a reduced tibial slope to compensate for instability, resulting from the deficient ACL. Knee kinematics was evaluated with a moving fluoroscope, tracking the knee joint during daily activities. In a standing position (baseline), posterior shift of the femur was observed for ACL-deficient UKA patients, compared to conventional UKA patients. RESULTS: A significant posterior femoral shift in the ACL-deficient group was observed during the first 25% (near extension) of deep knee bend, while there was no difference in kinematic waveforms for all other activities. No significant range of motion differences across different activities between the two UKA groups were detected, except for an increase of medial AP translation in the ACL-deficient group, during deep knee bend and stair descent. CONCLUSION: Despite the posterior femoral shift due to ACL deficiency, both UKA groups showed similar kinematic waveforms, indicating that posterior tibial slope reduction can partially compensate for ACL function. This supported our hypothesis that fixed bearing UKA can be a viable treatment option for selected ACL-deficient patients, allowing patient-specific kinematics. While anteroposterior laxity can be compensated, rotational stability was a prerequisite for this approach. LEVEL OF EVIDENCE: III.

EUROSPINE 2017 FULL PAPER AWARD: Time to remove our rose-tinted spectacles: a candid appraisal of the relative success of surgery in over 4500 patients with degenerative disorders of the lumbar spine, hip or knee.

PURPOSE: Studies comparing the outcome of spine surgery with that of large-joint replacement report equivocal findings. The patient-reported outcome measures (PROMs) used in such studies are typically generic and may not be sufficiently sensitive to the successes/failures of treatment. This study compared different indices of "success" in patients undergoing surgery for degenerative disorders of the lumbar spine, hip, or knee, using a validated, multidimensional, and joint-specific PROM. METHODS: Preoperatively and 12 months postoperatively, 4594 patients (3937 lumbar spine, 368 hip, 269 knee) undergoing first-time surgery completed a PROM that included the Core Outcome Measures Index (COMI) for the affected joint. The latter comprises a set of single items on pain, function, symptom-specific well-being, quality of life, and disability-all in relation to the specified joint problem. Other single-item ratings of treatment success were made 12 months postoperatively. RESULTS: In multiple regression analyses, controlling for confounders, the mean improvement in COMI at 12 months was greatest for the hip patients and lowest for those with degenerative spinal deformity (= the statistical reference group) (p < 0.05). Compared with spinal deformity, the odds of achieving "success" were: higher for hip (OR 4.6; 95% CI 2.5-8.5) and knee (OR 4.0; 95% CI 2.1-7.7) (no difference between spine subgroups) for "satisfaction with care"; higher for hip (OR 16.9; 95% CI 7.3-39.6), knee (OR 6.3; 95% CI 3.4-11.6), degenerative spondylolisthesis (OR 1.6; 95% CI 1.2-2.2), and herniated disc (OR 1.7; 95% CI 1.2-2.4) for "global treatment outcome"; and higher for hip (OR 13.8; 95% CI 8.8-21.6), knee (OR 5.3; 95% CI 3.6-7.8), degenerative spondylolisthesis (OR 1.6; 95% CI 1.3-2.1), and herniated disc (1.5; 95% CI 1.1-2.0) for "patient-acceptable symptom state". Patient-rated complications were the greatest in degenerative spinal deformity (29%) and the lowest in hip (18%). CONCLUSIONS: The current study is the largest of its kind and the first to use a common, but joint-specific instrument to report patient-reported outcomes after surgery for degenerative disorders of the spine, hip, or knee. The findings provide a sobering account of the significantly poorer outcomes after spine surgery compared with large-joint replacement. Further work is required to hone the indications and patient selection criteria for spine surgery. The data should be used to lobby research funding-bodies, governmental agencies, industry, and charitable foundations to invest more in spine research/registries, in the hope of ultimately improving spine outcomes. These slides can be retrieved under Electronic Supplementary Material.

Anterior Cruciate Ligament (ACL) Repair Using Dynamic Intraligamentary Stabilization Combined with Lateral Extra-articular Augmentation: A Case Report and Technical Note.

The treatment options for an anterior cruciate ligament (ACL) rupture range from conservative therapy to ACL repair and reconstruction. ACL repair is particularly suitable for younger patients with an acute proximal tear, and moderate athletic demand. Preserving the ACL can restore its proprioceptive and stabilizing functions, avoid donor site morbidity, and shorten rehabilitation time. Repair techniques include the use of suture anchors, internal brace augmentation, and dynamic intraligamentary stabilization. Dynamic intraligamentary stabilization employs a coil spring mechanism for dynamic tibial fixation, allowing posterior translation during knee flexion, which stabilizes the ACL for optimal healing. However, patients with a positive preoperative pivot shift test have shown worse postoperative outcomes and higher failure rates after ACL repair. To address this, lateral extraarticular augmentation is recommended during ACL reconstruction to restore stability and prevent graft failure. We present the case of a 27-year-old female recreational handball player who sustained an acute proximal ACL rupture. Arthroscopic ACL repair was performed using the technique of dynamic intraligamentary stabilization combined with lateral extra-articular augmentation in the modified Lemaire technique. At six weeks postoperatively, the patient presented with a hard endpoint at Lachman's test and negative pivot shift. At five months, the isokinetic strength testing showed above-average strength values. At eight months, the patient underwent hardware removal and arthroscopically showed a fully healed ACL. For the final examination 12 months postoperatively, the patient presented with in-reference strength values in isokinetic strength testing and excellent scoring in patient-reported outcome measurements. The combination of dynamic intraligamentary stabilization and lateral extra-articular augmentation demonstrates an adequate treatment option for patients with proximal ACL ruptures and immediate functional demands in moderate activity level sports due to the rapid achievement of clinical and subjective stability as well as excellent results in isokinetic strength testing.

The influence of implant design and limb alignment on in vivo wear rates of fixed-bearing and rotating-platform knee implant retrievals.

Analysis of polyethylene (PE) wear in knee implants is crucial for understanding the factors leading to revision in total knee arthroplasty. Importantly, current experimental and computational methods for predicting insert wear can only be validated against true in vivo measurements from retrievals. This study quantitatively investigated in vivo PE wear rates in fixed-bearing (FB) (n = 21) and rotating-platform (n = 53) implant retrievals. 3D surface geometry of the retrievals was measured using a structured light scanner. Then, a reference surface that included the deformation, but not the wear that the retrievals had experienced in vivo, was constructed using a fully automatic surface reconstruction algorithm. Finally, wear volume was calculated from the deviation between the worn and reconstructed surfaces. The measurement and analysis techniques were validated and the algorithm was found to produce errors of only 0.2% relative to the component volumes. In addition to quantifying cohort-level wear rates, the effect of mechanical axis limb alignment on mediolateral wear distribution was examined for a subset of the retrievals (n = 14 + 26). Our results show that FB implants produce significantly (p = 0.04) higher topside wear rates (24.6 ± 10.1 mm3/year) than rotating-platform implants (15.3 ± 8.0 mm3/year). This effect was larger than that of limb alignment, which had a smaller and nonsignificant influence on overall wear rates (+4.5 ± 11.6 mm3/year, p = 0.43). However, increased varus alignment was associated significantly with greater medial compartment wear in both the FB and rotating-platform designs (+1.7 ± 1.3%/° and +1.8 ± 1.6%/°). Our findings emphasize the importance of implant design and limb alignment on wear outcomes, providing reference data for improving implant performance and longevity.

Measurement properties of PROMIS short forms for pain and function in patients receiving knee arthroplasty.

BACKGROUND: While there are a few studies on measurement properties of PROMIS short forms for pain and function in patients with knee osteoarthritis, nothing is known about the measurement properties in patients with knee arthroplasty. Therefore, this study examined the measurement properties of the German Patient-Reported Outcomes Measurement Information System (PROMIS) short forms for pain intensity (PAIN), pain interference (PI) and physical function (PF) in knee arthroplasty patients. METHODS: Short forms were collected from consecutive patients of our clinic's knee arthroplasty registry before and 12 months post-surgery. Oxford Knee Score (OKS) was the reference measure. A subsample completed the short forms twice to test reliability. Construct validity and responsiveness were assessed using scale-specific hypothesis testing. For reliability, Cronbach's alpha, intraclass correlation coefficients, and agreement using standard error of measurement (SEMagr) were used. Agreement was used to determine standardised effect sizes and smallest detectable changes (SDC90). Individual-level minimal important change (MIC) was calculated using a method of adjusted prediction. RESULTS: Of 213 eligible patients, 155 received questionnaires, 143 returned baseline questionnaires and 119, 12-month questionnaires. Correlations of short forms with OKS were large (│r│ ≥ 0.7) with slightly lower values for PAIN, and specifically for men. Cronbach's alpha values were ≥ 0.84 and intraclass correlation coefficients ≥ 0.90. SEMagr were around 3.5 for PAIN and PI and 1.7 for PF. SDC90 were around 8 for PAIN and PI and 4 for PF. Follow-up showed a relevant ceiling effect for PF. Correlations with OKS change scores of around 0.5 to 0.6 were moderate. Adjusted MICs were 7.2 for PAIN, 3.5 for PI and 5.7 for PF. CONCLUSION: Our results partly support the use of the investigated short forms for knee arthroplasty patients. The ability of PF to differentiate between patients with high perceived recovery is limited. Therefore, the advantages and disadvantages should be strongly considered within the context of the intended use.

Comparable in vivo joint kinematics between self-reported stable and unstable knees after TKA can be explained by muscular adaptation strategies: A retrospective observational study.

Background: Postoperative knee instability is one of the major reasons accounting for unsatisfactory outcomes, as well as a major failure mechanism leading to total knee arthroplasty (TKA) revision. Nevertheless, subjective knee instability is not well defined clinically, plausibly because the relationships between instability and implant kinematics during functional activities of daily living remain unclear. Although muscles play a critical role in supporting the dynamic stability of the knee joint, the influence of joint instability on muscle synergy patterns is poorly understood. Therefore, this study aimed to understand the impact of self-reported joint instability on tibiofemoral kinematics and muscle synergy patterns after TKA during functional gait activities of daily living. Methods: Tibiofemoral kinematics and muscle synergy patterns were examined during level walking, downhill walking, and stair descent in eight self-reported unstable knees after TKA (3M:5F, 68.9 ± 8.3 years, body mass index [BMI] 26.1 ± 3.2 kg/m2, 31.9 ± 20.4 months postoperatively), and compared against 10 stable TKA knees (7M:3F, 62.6 ± 6.8 years, 33.9 ± 8.5 months postoperatively, BMI 29.4 ± 4.8 kg/m2). For each knee joint, clinical assessments of postoperative outcome were performed, while joint kinematics were evaluated using moving video-fluoroscopy, and muscle synergy patterns were recorded using electromyography. Results: Our results reveal that average condylar A-P translations, rotations, as well as their ranges of motion were comparable between stable and unstable groups. However, the unstable group exhibited more heterogeneous muscle synergy patterns and prolonged activation of knee flexors compared to the stable group. In addition, subjects who reported instability events during measurement showed distinct, subject-specific tibiofemoral kinematic patterns in the early/mid-swing phase of gait. Conclusions: Our findings suggest that accurate movement analysis is sensitive for detecting acute instability events, but might be less robust in identifying general joint instability. Conversely, muscle synergy patterns seem to be able to identify muscular adaptation associated with underlying chronic knee instability. Funding: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.

Triple Hybrid Tibial Anterior Cruciate Ligament Graft Fixation.

Optimal graft fixation in anterior cruciate ligament reconstruction is critical. Several direct and indirect methods of graft fixation exist, each with advantages and disadvantages. This Technical Note describes a tibial hybrid anterior cruciate ligament graft fixation technique combining direct and indirect fixation methods, including autologous bone augmentation of the drill tunnel using cancellous bone fragments.

The effect of femoral component rotation on the five-year outcome of cemented mobile bearing total knee arthroplasty.

PURPOSE: Performing total knee replacement, accurate alignment and neutral rotation of the femoral component are widely believed to be crucial for the ultimate success. Contrary to absolute bone referenced alignment, using a ligament balancing technique does not automatically rotate the femoral component parallel to the transepicondylar axis. In this context we established the hypothesis that rotational alignment of the femoral component parallel to the transepicondylar axis (0° ± 3°) results in better outcome than alignment outside of this range. METHODS: We analysed 204 primary cemented mobile bearing total knee replacements five years postoperatively. Femoral component rotation was measured on axial radiographs using the condylar twist angle (CTA). Knee society score, range of motion as well as subjective rating documented outcome. RESULTS: In 96 knees the femoral component rotation was within the range 0 ± 3° (neutral rotation group), and in 108 knees the five-year postoperative rotational alignment of the femoral component was outside of this range (outlier group). Postoperative CTA showed a mean of 2.8° (±3.4°) internal rotation (IR) with a range between 6° external rotation (ER) and 15° IR (CI 95). No difference with regard to subjective and objective outcome could be detected. CONCLUSION: The present work shows that there is a large given natural variability in optimal rotational orientation, in this study between 6° ER and 15° IR, with numerous co-factors determining correct positioning of the femoral component. Further studies substantiating pre- and postoperative determinants are required to complete the understanding of resulting biomechanics in primary TKA.

Towards planning of osteotomy around the knee with quantitative inclusion of the adduction moment: a biomechanical approach.

PURPOSE: Despite practised for decades, the planning of osteotomy around the knee, commonly using the Mikulicz-Line, is only empirically based, clinical outcome inconsistent and the target angle still controversial. A better target than the angle of frontal-plane static leg alignment might be the external frontal-plane lever arm (EFL) of the knee adduction moment. Hypothetically assessable from frontal-plane-radiograph skeleton dimensions, it might depend on the leg-alignment angle, the hip-centre-to-hip-centre distance, the femur- and tibia-length. METHODS: The target EFL to achieve a medial compartment force ratio of 50% during level-walking was identified by relating in-vivo-measurement data of knee-internal loads from nine subjects with instrumented prostheses to the same subjects' EFLs computed from frontal-plane skeleton dimensions. Adduction moments derived from these calculated EFLs were compared to the subjects' adduction moments measured during gait analysis. RESULTS: Highly significant relationships (0.88 ≤ R2 ≤ 0.90) were found for both the peak adduction moment measured during gait analysis and the medial compartment force ratio measured in vivo to EFL calculated from frontal-plane skeleton dimensions. Both correlations exceed the respective correlations with the leg alignment angle, EFL even predicts the adduction moment's first peak. The guideline EFL for planning osteotomy was identified to 0.349 times the epicondyle distance, hence deducing formulas for individualized target angles and Mikulicz-Line positions based on full-leg radiograph skeleton dimensions. Applied to realistic skeleton geometries, widespread results explain the inconsistency regarding correction recommendations, whereas results for average geometries exactly meet the most-consented "Fujisawa-Point". CONCLUSION: Osteotomy outcome might be improved by planning re-alignment based on the provided formulas exploiting full-leg-radiograph skeleton dimensions.

Five-year results of the Innex total knee arthroplasty system.

The clinical and radiographic results of 174 female and 86 male Innex (Zimmer, Warsaw, Indiana) mobile bearing total knee arthroplasty systems (245 patients) were evaluated, with particular emphasis on gender-related differences at five-year follow-up. Pre-operative Knee Society (KS) function and total scores were lower in women than in men. All KS scores showed a significant improvement at follow-up, but women still obtained lower KS function scores than men. Self-reported function was significantly better for male knees. No gender differences were observed for component alignment, while the occurrence of radiolucent lines, endosteal cavitations, and wear was significantly greater in male knees. Male Innex mobile bearing knees exhibited better clinical function and satisfaction than their female peers at five-year follow-up, despite inferior radiographic findings and higher revision rates.

Patient Expectations about Communication in the Perioperative Setting of Elective Knee Surgery - a Questionnaire-based Cross-sectional Study.

BACKGROUND: Patient expectations are an issue which is attracting increased interest in outcome research for knee surgery procedures. So far, research into patient expectations has mainly focused on the procedure and postoperative functional improvements. The purpose of this study was to identify patient expectations in the perioperative setting. MATERIAL AND METHODS: This was a single-center prospective study. A 17-item questionnaire (ordinal answer scale) about patients' perioperative expectations was developed and completed by patients undergoing elective joint-preserving knee surgery. The study covered a period of 3 months and included all patients consecutively undergoing knee surgery. Subgroup analysis was performed for gender, age and type of insurance. RESULTS: 111 consecutive patients completed the questionnaire on admission. Significant preferences for one answer option were found for 13 out of 17 items. Patients considered it "unimportant" whether or not the physician wore a white coat during the consultation and "very important" that the first medical consultation after the patient was discharged from hospital was with the surgeon who had performed their operation. A concise explanation of the surgical procedure using images, talking to the surgeon the day before surgery and immediately after surgery, having their wound personally inspected by the surgeon, and, finally, the availability of the surgeon by phone were regarded as "important". There were no differences in patient responses between the different subgroups. CONCLUSION: Patients expect a high personal commitment and availability of the surgeon during the entire perioperative setting, starting from the first consultation and continuing during follow-up examinations.

Attenuated suppression of the oxidative burst by cells dying in the presence of oxidized low density lipoprotein.

Macrophages ingesting apoptotic cells attenuate inflammatory responses, such as reactive oxygen species (ROS) generation. In atherosclerosis, ongoing inflammation and accumulation of apoptotic/necrotic material are observed, suggesting defects of phagocytes in recognizing or responding to dying cells. Modified lipoproteins such as oxidized LDL (oxLDL) are known to promote inflammation and to interfere with apoptotic cell clearance. Here, we studied the impact of cells exposed to oxLDL on their ability to interfere with the oxidative burst in phagocytes. In contrast to apoptotic cells, cells dying in response to or in the presence of oxLDL failed to suppress ROS generation despite efficiently being taken up by phagocytes. In addition, apoptotic cells, but not oxLDL-treated cells, inhibited phosphorylation of extracellular signal-regulated kinase, which is important for NADPH oxidase activation. oxLDL treatment did not interfere with activation of the antiinflammatory transcriptional regulator peroxisome proliferator-activated receptor gamma by apoptotic cells. Moreover, cells exposed to oxLDL failed to suppress lipopolysaccharide- induced proinflammatory cytokine expression, whereas apoptotic cells attenuated these phagocyte responses. Thus, the presence of oxLDL during cell death impaired the ability of apoptotic cells to act antiinflammatory with regard to oxidative burst inhibition and cytokine expression in phagocytes.

Association of body mass index and clinical outcome 2 years after unicompartmental knee arthroplasty.

INTRODUCTION: Unicompartmental knee arthroplasty (UKA) has gained in popularity during the last years. However, the body mass index (BMI) of patients undergoing UKA is controversially discussed in the literature. There is, moreover, a paucity of information available concerning the association of BMI with early clinical outcomes after UKA. MATERIALS AND METHODS: We retrospectively reviewed the clinical data of 83 consecutive UKA, 2 years after surgery, and investigated the potential association of BMI and the outcome variables Knee Society Score (KSS), University of California at Los Angeles (UCLA) activity levels, anterior knee pain (AKP), range of motion, and implant failure. RESULTS: The KSS and UCLA significantly increased from 132 and 4.7 preoperatively to 187.5 and 7.1, respectively, after surgery. Knee flexion significantly improved from 123.7 to 128.4 degrees and the prevalence of extension deficiencies significantly decreased from 28.9 to 15.7%. Three knees (3.6%) failed and were converted to total knee arthroplasty. Failures were not associated with increased BMI (P = 0.387). The BMI had no significant association with KSS values, UCLA levels, and implant failure. We found a weak negative correlation between BMI and postoperative knee flexion (r = -0.285, P = 0.009) and a moderate positive correlation between BMI and the intensity of AKP (r = 0.525, P < 0.001). CONCLUSION: The results of the present study suggest that the BMI of patients undergoing UKA has no major impact on the early clinical outcome 2 years after surgery. There was, however, a definite correlation between the BMI and AKP. Longer follow-up is necessary to determine if overweight and obesity may increase revision rates after UKA.

Correlation between the AMADEUS score and preoperative clinical patient-reported outcome measurements (PROMs) in patients undergoing matrix-induced autologous chondrocyte implantation (MACI).

BACKGROUND: Recently, the AMADEUS (Area Measurement And DEpth Underlying Structures) grading system has been introduced to evaluate and grade osteochondral lesions prior to cartilage surgery. The AMADEUS score has not been connected to clinical data in order to test a potential clincial impact. PURPOSE: To examine the correlation between the AMADEUS score and preoperative patient-reported outcome measurements (PROMs). STUDY DESIGN: Case series METHODS: Patients treated with matrix-induced autologous chondrocyte implantation (MACI) were included in the study, unless exclusion criteria like BMI > 35, prior extensive meniscectomy or ongoing inflammatory arthritis were present. Preoperative magnetic resonance (MR) examinations were graded according to the standardized AMADEUS protocol. The final AMADEUS score was correlated with preoperative patient-reported outcome measurements (PROMs), including the IKDC (International Knee Documentation Committee), the Lysholm score, the Short-Form-12 (SF-12) score, and the Core Outcome Measures Index (COMI) score. RESULTS: A total of 50 patients with a mean age of 33.6 ± 11.5 years, a mean BMI of 25.1 ± 4.9, and a mean defect size of 2.3 ± 1.5 cm2 were included in the study. More severe cartilage defects, indicated by the AMADEUS grade (R = 0.35, p = 0.01) and the AMADEUS score (R = - 0.36, p = 0.01) as well as larger chondral defects (R = 0.32, p = 0.03) show a moderate correlation with the higher COMI scores. No correlative capacity was demonstrated for the AMADEUS score and the IKDC, Lysholm, and Tegner activity scores as well as for its subscales. CONCLUSION: There is a moderate correlation of the COMI and the AMADEUS score in patients treated with matrix-induced autologous chondrocyte implantation (MACI). All other patient-reported outcome measurement scores (PROMs) show no evidence of an association to the magnetic resonance-based AMADEUS score. CLINICAL RELEVANCE: The clinical and scientific implication of the COMI score as a PROM tool can be recommended when working with the AMADEUS score and patients undergoing MACI.

One-Step Autologous Minced Cartilage Procedure for the Treatment of Knee Joint Chondral and Osteochondral Lesions: A Series of 27 Patients With 2-Year Follow-up.

BACKGROUND: Chondral and osteochondral lesions are being detected with increasing frequency. For large-diameter lesions, cell-based treatment modalities are speculated to result in the best possible outcome. PURPOSE: To prospectively evaluate the 2-year clinical and radiological results after the treatment of chondral and osteochondral knee joint lesions by a single-step autologous minced cartilage procedure. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: From February 2015 to June 2016, a total of 27 consecutive patients suffering from chondral or osteochondral lesions of the knee joint were treated using a single-step autologous minced cartilage procedure. All patients underwent preoperative and postoperative magnetic resonance imaging for the collection of AMADEUS (Area Measurement and Depth and Underlying Structures) and MOCART (magnetic resonance observation of cartilage repair tissue) scores. Clinical analysis was conducted by a numeric analog scale (NAS) for pain and knee function before the intervention and at 12 and 24 months postoperatively. RESULTS: A total of 12 female and 15 male patients (mean age, 28.7 years) were evaluated for a mean of 28.2 ± 3.8 months. The mean cartilage defect size encountered intraoperatively was 3.1 ± 1.6 cm2. There was a significant decrease in pain from 7.2 ± 1.9 preoperatively to 1.8 ± 1.6 (P < .001) at 2-year follow-up. Knee function improved from a mean of 7.2 ± 2.0 preoperatively to 2.1 ± 2.3 (P < .001) at 2 years after surgery. The mean preoperative AMADEUS score was 57.4 ± 21.4. Postoperatively, the mean MOCART score was 40.6 ± 21.1 at 6-month follow-up. No correlation was observed between the clinical data and the MOCART or AMADEUS scores. CONCLUSION: Overall, the findings of this study demonstrated that patients undergoing a single-step autologous minced cartilage procedure had a satisfactory outcome at 2-year follow-up. As a result, the single-step autologous minced cartilage procedure does represent a possible alternative to standard autologous chondrocyte implantation. Longer follow-up and larger cohorts are required to define the benefits of this procedure.

Is ACL deficiency always a contraindication for medial UKA? Kinematic and kinetic analysis of implanted and contralateral knees.

BACKGROUND: Prevalence of knee osteoarthritis increases because life expectancy continues to rise with an active patient population. Hence, the concept of unicompartmental knee arthroplasty (UKA) has regained popularity as a treatment option for unicompartmental knee osteoarthritis. Anterior cruciate ligament (ACL) deficiency is widely considered as a contraindication for UKA, however, there are conflicting reports. If otherwise indicated, some surgeons consider UKA for ACL-deficient patients using a modified surgical technique, with a reduction of posterior tibial slope. RESEARCH QUESTION: The purpose of this study was to evaluate outcomes in UKA patients with ACL deficiency in comparison to a conventional UKA group (intact ACL) by the measurement of knee kinematics and kinetics. METHODS: Ten patients with conventional UKA and an intact ACL and eight patients with an ACL-deficient UKA and a reduced posterior tibial slope relative to the native knee were recruited. Three-dimensional joint kinematics of the knee were measured, using skin markers and an infrared optical motion capture system. Ground reaction forces (GRF) were measured with force plates in all three directions. Level walking, ramp descent and stair descent were analyzed, comparing implanted and contralateral native knees and the two UKA groups. RESULTS: No significant differences in kinetics and kinematics were observed between conventional UKA and ACL-deficient UKA groups for any of the activities. However, some asymmetries in GRF between the implanted and contralateral side were present for the ACL-deficient group, during level walking (unloading rate) and stair descent (stance time). SIGNIFICANCE: Promising outcomes of the ACL-deficient UKA group suggest that ACL deficiency may not always be a contraindication. Therefore, ACL-deficient UKA could be an alternative treatment option to total knee arthroplasty for an appropriate surgeon selected patient population.