Treatment of Large Knee Osteochondral Lesions With a Biomimetic Scaffold: Results of a Multicenter Study of 49 Patients at 2-Year Follow-up.

BACKGROUND: Osteochondral knee lesions represent a challenging condition encountered by orthopaedic surgeons. A variety of methods have been developed to repair articular cartilage defects. However, these techniques are limited by donor site morbidity or by the requirement for a staged procedure. PURPOSE: To assess the effectiveness of a biomimetic osteochondral scaffold for the treatment of large osteochondral knee lesions. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: From 2009 to 2011, a total of 49 patients affected by isolated large osteochondral knee lesions (mean [± SD] size, 4.35 ± 1.26 cm2) were treated with the biomimetic scaffold. Patients were evaluated using the International Knee Documentation Committee (IKDC), Tegner, and visual analog scale (VAS) pain scores, as well as magnetic resonance imaging (MRI) up to 3-year follow-up. The MOCART (magnetic resonance observation of cartilage repair tissue) score was performed to analyze different variables. Biopsies were carried out in 5 patients. Four of the 5 second-look arthroscopies and biopsies were performed on patients with failed results because of ethical issues. RESULTS: The mean IKDC subjective score increased significantly from 45.45 ± 19.29 preoperatively to 70.86 ± 18.08 at 1-year follow-up and to 75.42 ± 19.31 at 2-year follow-up (P < .001). The IKDC objective score changed from 50% normal and nearly normal knees before treatment to 89.79% at the 2-year follow-up. There was a statistically significant improvement (P < .005) in VAS score from the preoperative level (6.69 ± 1.88) to the 2-year follow-up (1.96 ± 2.47). Tegner scores increased (P < .001) from the preoperative value (2.20 ± 0.67) to the 2-year follow-up (4.9 ± 1.73) without achieving preinjury level. A correlation was found between the IKDC subjective score and age (P < .001, r = -0.497, ρ = -0.502). Patients affected by osteochondritis dissecans (OCD) achieved a statistically significantly better outcome (P < .05). A subgroup of 19 competitive athletes showed a statistically significantly improvement (P < .001) in the subjective IKDC (86.5 ± 13.2) compared with the nonathletic subpopulation (69.03 ± 19.41) at the 2-year follow-up. The MRI findings of 30 patients were available at 2-year follow-up: 70% showed complete filling of the lesion, 63.3% had an intact articular surface, and 86% had mild or no effusion. In all cases, in dual T2-weighted fast spin echo sequence, the repair tissue showed a hyperintensive signal with respect to the surrounding subchondral bone; however, no edema was observed. CONCLUSION: The study findings indicate that the biomimetic scaffold that was investigated is an off-the-shelf, cell-free, and cost-effective implant that can regenerate either cartilage or subchondral bone. The scaffold allows a 1-step surgical procedure that can be used for osteochondral lesions, OCD, and in some cases osteonecrosis.

Use of innovative biomimetic scaffold in the treatment for large osteochondral lesions of the knee.

PURPOSE: Large osteochondral defects involve two different tissues characterized by different intrinsic healing capacity. Different techniques have been proposed to treat these lesions with results still under discussion. The aim of the study is to evaluate the clinical outcome of 19 patients treated with a type I collagen-hydroxyapatite nanostructural biomimetic osteochondral scaffold at minimum follow-up of 2 years. METHODS: Twenty lesions, 19 patients were treated with this scaffold implantation. The lesions size went from 4 to 8 cm(2) (mean size 5.2 ± 1.6 cm(2)). All patients were clinically evaluated using the International Repair Cartilage Society score, the Tegner Score and EQ-VAS. MRI was performed at 12 and 24 months after surgery and then every 12 months and evaluated with magnetic resonance observation of cartilage repair tissue scoring scale. RESULTS: The IKDC subjective score improved from a mean score of 35.7 ± 6.3 at the baseline evaluation to 67.7 ± 13.4 at 12-month follow-up (p < 0.0005). A further improvement was documented from 12 to 24 months (mean score of 72.9 ± 12.4 at 24 months) (p < 0.0005). The IKDC objective score confirmed the results. The Tegner activity score improvement was statistically significant (p < 0.0005). The EQ-VAS showed a significant improvement from 3.15 ± 1.09 to 7.35 ± 1.14 (p < 0.0005) at 2-year follow-up. The lesion' site seems to influence the results showing a better outcome in the patients affected in the medial femoral condyle. CONCLUSIONS: The use of the MaioRegen scaffold is a good procedure for the treatment for large osteochondral defects where other classic techniques are difficult to apply. It is an open one-step surgery with promising stable results at medium follow-up. LEVEL OF EVIDENCE: IV.

The use of an eccentric glenosphere compared with a concentric glenosphere in reverse total shoulder arthroplasty: two-year minimum follow-up results.

PURPOSE: The current models of reverse shoulder arthroplasty (RSA) expose the procedure to the risk of scapular notching, possibly leading to loosening of the glenoid. We compared the clinical and radiographic results obtained with a concentric or eccentric glenosphere to assess whether the eccentric design might give better clinical results and avoid or decrease the risk of scapular notching METHODS: Of our patients, 31 underwent RSA using a concentric glenosphere (group A), while 29 had an eccentric glenosphere (group B). Postoperatively, patients were followed-up at one to 12 months and annually thereafter, with the mean being 33 months in group A and 27.5 in group B. In both groups the minimum follow up (F-U) was 24 months. Preoperatively and at each F-U starting from six months, patients were assessed using the Constant score. On radiographs, prosthesis scapular neck angle (PSNA), distance between scapular neck and glenosphere (DBSNG) and peg-glenoid rim distance (PGRD) were calculated. The severity of notching was classified in four grades. RESULTS: In group A the mean Constant score increased by 30 points compared to the preoperative score and the active ROM increased considerably. At latest F-U, the mean PSNA, DBSNG and PGRD were, respectively, 87°, 3.4 mm and 19.8 mm. Glenoid notching was present in 42% of cases. In group A, the mean Constant score increased by 34 points and the mean ROM was better than in group A. The average PSNA, PGRD and DBSNG were, respectively, 92°, 21.2 mm and 4.3 mm. Radiographs showed no inferior scapular notching. CONCLUSIONS: The eccentric glenosphere yielded better clinical results than the concentric glenosphere and was associated with no scapular notching.

Conversion of shoulder arthroplasty to reverse implants: clinical and radiological results using a modular system.

PURPOSE: Revision of a shoulder arthroplasty to a reverse arthroplasty is a highly demanding procedure. The aim of this study is to report the clinical results of hemi and total shoulder prosthesis revisions to reverse implants without removal of the humeral stem, using a modular shoulder replacement system (SMR Lima LTD). We retrospectively reviewed 26 patients who underwent an operation from 2004 to 2009. METHODS: The patients were divided into two groups: in Group I, 18 patients underwent a revision of hemiarthroplasty implanted for fracture; in Group II, eight patients underwent a revision of anatomical total prosthesis. All patients were evaluated at a mean follow-up of 32.3 (±12.7) months using the Constant score rating scale and by range of motion evaluation, EQ-VAS, X-ray and CT scan. RESULTS: The Constant score of each patient was 47.88 (±5.88) after the revision. The EQ-VAS improved from 40 (±20) to 70 (±10). All patients improved in terms of range of motion. The radiographs and CT scans obtained after revision showed good integration and no signs of loosening of the implant. The mean time of surgery was recorded as 62' (±8'), with a maximum blood loss of less than 300 ml in all cases. CONCLUSIONS: Our study demonstrates that using a full modular system at the time of the first implant allows avoidance of the step to remove the humeral stem and metal back in cases of shoulder prosthesis revision to a reverse prosthesis, resulting in a short operative time, few intraoperative complications and a satisfactory clinical outcome at medium-term follow-up.

Reverse total shoulder arthroplasty: radiological and clinical result using an eccentric glenosphere.

In reverse shoulder arthroplasty, an eccentric glenosphere has been developed with the aim of lowering the centre of rotation, in order to prevent inferior scapular notching as occurs with concentric designs. The objective of this retrospective study was to evaluate clinical and radiographic outcomes using the eccentric glenosphere and to determine whether this design might prevent inferior scapular notching. Between 2006 and 2010, 40 patients affected by cuff tear arthropathy underwent reverse shoulder arthroplasty with an eccentric 36-mm glenoid component. Patients with less than 2 years' follow-up were excluded. The results for 25 patients with a minimum of 24 months' follow-up are reported. Clinical and radiographic evaluation was performed preoperatively and at 1, 3, 6 months, 1 year and annually thereafter. All patients were evaluated with MRI or CT scan preoperatively and with X-ray examinations postoperatively to evaluate the presence of inferior scapular notching and to measure the prosthesis-scapular neck angle (PSNA), the peg-glenoid rim distance (PGRD) and the distance between the scapula neck and the glenosphere. At last follow-up (average 27.5 months, range 24-46), the Constant Score, the VAS score and range of motion had improved significantly. The average PSNA was 92° + 29°, the average PGRD was 21.2 mm + 9 mm and the average distance between the inferior bony glenoid rim and the inferior edge of the glenosphere was 4.3 mm + 0.8 mm. No inferior scapular notching and no implant-related complications were seen. The data suggest that use of an eccentric glenosphere lowers the centre of rotation, reducing the risk of inferior scapular notching. Level of evidence IV.