Purpose: A three-year evaluation of long-term clinical efficacy of Characterized Chondrocyte Implantation (CCI) compared to microfracture (MF), in the repair of symptomatic cartilage defects of the femoral condyles at 36 months post-surgery.

Materials and Methods: In a prospective, randomized, controlled, multicenter trial, CCI was compared to MF in patients aged 18–50 years with a single symptomatic ICRS grade III–IV lesion of the knee. Clinical outcome was measured 36 months after surgery by means of the KOOS, VAS for pain and ARS, with a non-inferiority margin preset at 9 % points for KOOS and VAS. Furthermore, response to treatment and progression of knee symptoms were assessed. Treatment failure was monitored throughout the study.

Results: Improvement from baseline was higher in the CCI group (N = 41) compared to the MF group (N = 49) for all clinical outcome parameters. Mean improvement from baseline for Overall KOOS was 22.14 vs. 14.48, respectively, with VAS and ARS scores revealing a similar trend. Responder analysis showed 83% of the patients treated with CCI improving vs. 61% after MF. Additionally, we observed a shift in the proportion of knee symptoms over time (52% vs. 35% of asymptomatic knees at 36 months compared to 2% vs. 8% at baseline in the CCI and MF group respectively). At 36 months, failure rates were low in both groups (n=2 in CCI vs. n=7 in MF).

Conclusions: Previous data have described a superior structural repair after CCI compared to MF at 1 year post-surgery. Continued clinical improvement as well as a favorable responder analysis was demonstrated for CCI compared to MF at 36 months.

The purpose of the current study was to compare mid-term outcomes of posterior cruciate retaining(CR) versus posterior cruciate substituting (PS)procedures, using the Genesis II total knee arthroplasty (TKA) system(Smith and Nephew, Memphis TN). Ninety nine CR and 93 PS TKA’s were analysed in this prospective, randomised, clinical trial. Surgeries were performed at seven medical centres by participating surgeons. Clinical outcomes (Knee Society Score, Range of Motion, WOMAC, SF 12 : and radiographic findings), in addition to postoperative complications, were evaluated with a minimum follow-up of five years. Following data analysis, there were no Significant differences in patient demographics or pre-operative clinical measures between the two groups. At the latest follow-up interval, no Significant differences were found between the CR and PS groups with regard to functional assessment, patient satisfaction or post-operative complications. However the PS group did display statistically Significant improvements in range of motion when compared with the CR group. The results of this investigation would suggest that while comparable in regards to supporting good clinical outcomes, the PS Genesis II design does appear to support significantly improved post-operative range of motion when compared with the CR design

Purpose: As a one-step surgical procedure, microfracture is frequently considered to be technically easier and associated with less postoperative morbidity than autologous chondrocyte implantation (ACI), which involves both arthrotomy and arthroscopy and therefore safety was assessed in patients with symptomatic cartilage lesions of the knee treated with characterized chondrocyte implantation (CCI) or microfracture.

Methods: CCI (n=57) was compared to microfracture (n=61) in patients with grade III–IV symptomatic cartilage defects of the femoral condyles in a Phase III, prospective, multi-center, randomized, controlled trial. Safety assessments included adverse events (AEs), physical examination, vital signs, hematology and clinical chemistry.

Results: At 18 months post-surgery, similar proportions of patients experienced AEs in the CCI (88%) and microfracture (82%) groups; 67% and 59%, respectively, experienced AEs considered treatment related. The AE profile was generally similar between groups, with no significant difference for hypertrophy, although significantly more CCI-treated patients had joint swelling (19% versus 4.9%; p=0.022) and treatment-related joint crepitation (12% versus 1.6%; p=0.028). Although the proportion of patients with severe AEs was similar for CCI (12%) and microfracture (13%), slightly more microfracture-treated patients experienced serious (life-threatening or requiring hospitalization) AEs (13% versus 8.8%). No patients discontinued due to AEs or died during the study.

Conclusion: Contrary to general opinion, the two-step CCI procedure, involving arthroscopy followed by arthrotomy, has a similar safety profile to that of microfracture, a one-step arthroscopic procedure, for treating cartilage lesions of the knee.

Purpose: This study compared the efficacy and safety of Characterized Chondrocyte Implantation (CCI) to microfracture in the repair of symptomatic cartilage defects of the femoral condyle.

Methods: CCI (n=51) was compared to microfracture (n=61) in patients with grade III–IV symptomatic cartilage defects of the femoral condyles in a prospective, multicenter, randomized, controlled trial. Structural repair was assessed at 1 year by histopathologists blinded to the treatment using

computerized histomorphometry and

Results: CCI resulted in better structural repair than microfracture at 1 year post-treatment, as assessed by histomorphometry (p=0.003) and overall histology (p=0.012). Structural repair parameters relating to chondrocyte phenotype and tissue structure were also superior with CCI. Noninferiority of CCI was demonstrated for clinical outcome at 12–18 months, and both treatments were generally well tolerated.

Conclusion: At 1 year post-treatment, CCI resulted in superior tissue repair compared to microfracture. Short-term clinical outcome after 12–18 months was similar for both treatments, as was the safety profile. The superior structural repair achieved with CCI may lead to improved long-term clinical benefits.

Aims: The aim of the study was to determine the accuracy of the kinematical determination of the centre of rotation of the hip and to compare the outcome of the Computer assisted surgery (CAS) group versus a control group of patients with conventionally instrumented TKA, in a prospective randomized way. Methods: A prospective, randomized and controlled trial was undertaken with an image based CAS system (ION®), using specific knee software for the GENESIS II®total knee system. Randomization was performed on a consecutive group of 50 primary TKA’s, without exclusion criteria. All computed kinematical centres of rotation of the hip were compared to the anatomic fluoroscopic images. The difference between the kinematical centre of rotation and the anatomic centre of the femoral head was measured in the frontal plane. Coronal alignment was measured on full leg standing films. Validation of the full leg standing films was carried out in comparing the pre-operative measured angle and the computed deformity angle at the beginning of the surgery. Outcome of the CAS group was compared to the conventional group on the following items: tourniquet time, operative time, blood loss, patellar alignment, tibial slope, coronal alignment, range of motion and complications. Results: ACCURACY: The correlation index between pre-op full legs and CAS measured values was excellent: r²=0.997. Difference between kinematical centre of rotation and anatomic centre of the hip: mean deviation between the two points was 1.2 mm (0–4mm), stdv 1.2 mm. This corresponds with a mean angular deviation of 0.17° (0–0.57°). OUTCOME: Tourniquet time: conventional 56 min., CAS 72 min. p=0.002. Operative time: conventional 70 min., CAS 93 min. p< 0.001. Blood loss: conventional 3.3 g/dl, CAS 4 g/dl. Patellar alignment: no tilt > 5°, no subluxation > 3 mm, both groups. Tibial slope: conventional 3.5°, CAS 3°. Post-operative mechanical alignment was between 0 and 2° of deformity for 16 conventional knees, and between 3–4° for 5 conventional knees. In the CAS group, all 21 knees scored between 0° and 2° of mechanical alignment. ROM at 6 weeks: flexion conventional 106°, CAS 105°. Fixed flexion contracture: conventional 2.9, CAS 2.1. Complications: delayed wound healing: conventional 2, CAS 1. Conclusions: Computer assisted kinematical determination of the centre of the hip can be highly accurate. Post-operative coronal alignment in CAS group is excellent, however not significantly better than conventional instrumentation.