Dextran-tryamine hydrogel maintains position and integrity under simulated loading in a human cadaver knee model.

Objective: This dextran-tyramine hydrogel is a novel cartilage repair technique, filling focal cartilage defects to provide a cell-free scaffold for subsequent cartilage repair. We aim to asses this techniques' operative feasibility in the knee joint and its ability to maintain position and integrity under expected loading conditions. Method: Seven fresh-frozen human cadaver legs (age range 55-88) were used to create 30 cartilage defects on the medial and lateral femoral condyles dependent of cartilage quality, starting with 1.0 â€‹cm2; augmenting to 1.5 â€‹cm2 and eventually 2.0 â€‹cm2. The defects were operatively filled with the injectable hydrogel scaffold. The knees were subsequently placed on a continues passive motion machine for 30 â€‹min of non-load bearing movement, mimicking post-operative rehabilitation. High resolution digital photographs documented the hydrogel scaffold after placement and directly after movement. Three independent observers blinded for the moment compared the photographs on outline attachment, area coverage and hydrogel integrity. Results: The operative procedure was uncomplicated in all defects, application of the hydrogel was straightforward and comparable to common cartilage repair techniques. No macroscopic iatrogenic damage was observed. The hydrogel scaffold remained predominately unchanged after non-load bearing movement. Outline attachment, area coverage and hydrogel integrity were unaffected in 87%, 93% and 83% of defects respectively. Larger defects appear to be more affected than smaller defects, although not statistically significant (p â€‹> â€‹0.05). Conclusion: The results of this study show operative feasibility of this cell-free hydrogel scaffold for chondral defects of the knee joint. Sustained outline attachment, area coverage and hydrogel integrity were observed after non-load bearing knee movement.

Automated Radiographic Measurements of Knee Osteoarthritis.

OBJECTIVE: Herewith, we report the development of Orthopedic Digital Image Analysis (ODIA) software that is developed to obtain quantitative measurements of knee osteoarthritis (OA) radiographs automatically. Manual segmentation and measurement of OA parameters currently hamper large-cohort analyses, and therefore, automated and reproducible methods are a valuable addition in OA research. This study aims to test the automated ODIA measurements and compare them with available manual Knee Imaging Digital Analysis (KIDA) measurements as comparison. DESIGN: This study included data from the CHECK (Cohort Hip and Cohort Knee) initiative, a prospective multicentre cohort study in the Netherlands with 1,002 participants. Knee radiographs obtained at baseline of the CHECK cohort were included and mean medial/lateral joint space width (JSW), minimal JSW, joint line convergence angle (JLCA), eminence heights, and subchondral bone intensities were compared between ODIA and KIDA. RESULTS: Of the potential 2,004 radiographs, 1,743 were included for analyses. Poor intraclass correlation coefficients (ICCs) were reported for the JLCA (0.422) and minimal JSW (0.299). The mean medial and lateral JSW, eminence height, and subchondral bone intensities reported a moderate to good ICC (0.7 or higher). Discrepancies in JLCA and minimal JSW between the 2 methods were mostly a problem in the lateral tibia plateau. CONCLUSIONS: The current ODIA tool provides important measurements of OA parameters in an automated manner from standard radiographs of the knee. Given the automated and computerized methodology that has very high reproducibility, ODIA is suitable for large epidemiological cohorts with various follow-up time points to investigate structural progression, such as CHECK or the Osteoarthritis Initiative (OAI).

Relaxation of the MCL after an Open-Wedge High Tibial Osteotomy results in decreasing contact pressures of the knee over time.

PURPOSE: The objective of this study was to investigate the effect of a medial open-wedge osteotomy (OWO) and the release of the superficial medial collateral ligament (MCL) on the tibiofemoral cartilage pressure, the MCL tension and the valgus laxity of the knee. METHODS: Seven fresh-frozen, human cadaveric knees were used. Medial and lateral mean contact pressure (CP), peak contact pressure (peakCP), and contact area (CA) were measured using a pressure-sensitive film (I-Scan; Tekscan, Boston, MA). The MCL tension was measured using a custom-made device. These measurements were continuously recorded for 5 min after an OWO of 10°. After the osteotomy, the valgus laxity was measured with a handheld Newtonmeter. For one knee, the measurements were continued for 24 h. At the end, a complete release of the superficial MCL was performed and the measurements were repeated at 10°. RESULTS: There was relaxation of the MCL after the osteotomy; the tension dropped in 5 min with 10.7% (mean difference 20.5 N (95% CI 16.1-24.9)), and in 24 h, the tension decreased by 24.2% (absolute difference 38.8 N) (one knee). After the osteotomy, the mean CP, peakCP and CA increased in the medial compartment (absolute difference 0.17 MPa (95% CI 0.14-0.20), 0.27 MPa (95% CI 0.24-0.30), 132.9mm2 (95% CI 67.7-198.2), respectively), and decreased in the lateral compartment (absolute difference 0.02 MPa (95% CI 0.03 -0.01), 0.08 MPa (95% CI 0.11 - 0.04), 47.0 mm2 (95% CI -105.8 to 11.8), respectively). Only after a release of the superficial MCL, the mean CP, peak CP and CA significantly decreased in the medial compartment (absolute difference 0.17, 0.27 MPa, 119.8 mm2, respectively), and increased in the lateral compartment (absolute difference 0.02, 0.11 MPa, 52.4 mm2, respectively). After the release of the superficial MCL, a mean increase of 7.9° [mean difference - 0.1° (95% CI -1.9 to 1.6)] of the valgus laxity was found. CONCLUSIONS: A release of the superficial MCL helps achieve the goal of reducing medial cartilage pressure in an OWO. There was considerable relaxation of the MCL after an OWO that resulted in a decrease of the mean CP in the medial and lateral compartments of the knee over time. However, cartilage pressure shifted from the medial to the lateral compartment only after release of the superficial MCL. The release of the superficial MCL caused a significant increase in the valgus laxity, which could influence stability after an OWO. LEVEL OF EVIDENCE: I.

Gait analysis before and after corrective osteotomy in patients with knee osteoarthritis and a valgus deformity.

PURPOSE: In this prospective study, the changes in kinetics and kinematics of gait and clinical outcomes after a varus osteotomy (tibial, femoral or double osteotomy) in patients with osteoarthritis (OA) of the knee and a valgus leg alignment were analysed and compared to healthy subjects. METHODS: Twelve patients and ten healthy controls were included. Both kinetics and kinematics of gait and clinical and radiographic outcomes were evaluated. RESULTS: The knee adduction moment increased significantly postoperatively (p < 0.05) and almost similar to the control group. Patients showed less knee and hip flexion/extension motion and moment during gait pre- and postoperatively compared to the controls. A significant improvement was found in WOMAC [80.8 (SD 16.1), p = 0.000], KOS [74.9 (SD 14.7), p = 0.018], OKS [21.2 (SD 7.5), p = 0.000] and VAS-pain [32.9 (SD 20.9), p = 0.003] in all patients irrespective of the osteotomy technique used. The radiographic measurements showed a mean hip knee ankle (HKA) angle correction of 10.4° (95 % CI 6.4°-14.4°). CONCLUSION: In patients with knee OA combined with a valgus leg alignment, the varus-producing osteotomy is a successful treatment. Postoperatively, the patients showed kinetics and kinematics of gait similar as that of a healthy control group. A significant increase in the knee adduction moment during stance phase was found, which was related to the degree of correction. The HKA angle towards zero degrees caused a medial shift in the dynamic knee loading. The medial shift will optimally restore cartilage loading forces and knee ligament balance and reduces progression of OA or the risk of OA. A significant improvement in all clinical outcomes was also found. LEVEL OF EVIDENCE: III.

Is There A Difference In Outcome Between Two Types Of Valgus Unloading Braces? A Randomized Controlled Trial.

The short-term clinical and radiographic outcomes of two different valgus unloading braces were compared in patients with medial knee osteoarthritis (OA) and a varus leg alignment. A RCT was performed in 100 patients (50 Bledsoe Thruster brace, 50 SofTec OA brace) with symptomatic medial knee OA and a varus leg alignment. Outcomes were the visual analogue scale pain and satisfaction, Dutch Western Ontario and McMaster Universities Osteoarthritis Index, SF-12, 6-Minutes Walking Test, hip-knee-ankle alignment, analgesic use, complications and compliance after a follow-up of 2 and 12 weeks. The clinical and radiographic outcomes were not significant different between both groups. Almost all clinical outcomes improved in both groups at follow-up compared to baseline. 24% of the patients discontinued using the brace. No significant differences in clinical and radiographic outcomes were found between both groups after 2 and 12 weeks follow-up. Both braces were effective in the treatment of varus medial knee OA. Complications and compliance remains a problem.

Better clinical results after closed- compared to open-wedge high tibial osteotomy in patients with medial knee osteoarthritis and varus leg alignment.

PURPOSE: Studies comparing mid- or long-term outcomes of open- and closed-wedge high tibial osteotomy are limited. Here, the midterm survival rate and clinical and radiographic outcomes were compared for these two techniques. The study hypothesis, based on short-term follow-up, was that after midterm follow-up, the two techniques would not differ. METHODS: A prospective follow-up study was conducted for a previously reported randomized controlled trial of an original 50 patients (25 open-wedge osteotomy and 25 closed-wedge osteotomy) with medial knee osteoarthritis and a varus leg alignment. We analyzed patients without knee arthroplasty (mean age 48.7 years, SD 8.0) for clinical and radiographic follow-up. RESULTS: Five patients in each group had undergone conversion to a total knee arthroplasty or unicompartmental knee arthroplasty, leaving 19 patients for analysis in each group. At 7.9 years of follow-up (range 7-9 years), survival did not differ significantly between groups (open-wedge group 81.3% [95% confidence interval (CI) 75.2-100], closed-wedge group 82.0% [95% CI 66.7-100]). At final follow-up, total Dutch Western Ontario and McMaster Universities Arthritis (WOMAC), Knee Society Score, and visual analog scale (VAS) pain did not differ between groups. However, the results were significantly better in the closed-wedge group for VAS satisfaction and WOMAC pain and stiffness compared to the open-wedge group. Radiographic evaluation did not differ between groups for any outcome at final follow-up. CONCLUSION: After a mean follow-up of 7.9 years, patients undergoing a closed-wedge osteotomy had favorable clinical results compared to those who underwent an open-wedge osteotomy. LEVEL OF EVIDENCE: II.

[Fatal interstitial lung disease associated with erlotinib use]. / Fataal interstitieel longbeeld bij erlotinib-gebruik.

BACKGROUND: Erlotinib is used to treat patients with non-small cell lung cancer (NSCLC). The use of this tyrosine kinase inhibitor can result in interstitial lung disease, but the aetiology of this phenomenon is not clear. CASE DESCRIPTION: A 68-year-old man with NSCLC, who had been undergoing treatment with erlotinib (150 mg daily) for the previous two weeks, presented with dyspnoea. A chest x-ray revealed infiltrates for which we started broad-spectrum antibiotics, high dose glucocorticoids and oxygen supplementation; erlotinib was discontinued. Despite these measures, the patient died of respiratory failure. Autopsy showed diffuse alveolar damage; the blood cultures taken while the patient was still alive and the post-mortem lung cultures were negative. The alveolar damage was possibly a consequence of the use of erlotinib. CONCLUSION: Clinicians should be alert to worsening pulmonary symptoms without signs of infection in patients using erlotinib. Discontinuation of erlotinib and glucocorticoid treatment should be considered until alveolar damage caused by the use of erlotinib can be excluded.