Mapping tibiofemoral gonarthrosis: an MRI analysis of non-traumatic knee cartilage defects.

OBJECTIVE: Arthroscopy is "the gold standard" for the diagnosis of knee cartilage lesions. However, it is invasive and expensive, and displays all the potential complications of an open surgical procedure. Ultra-high-field MRI now offers good opportunities for the indirect assessment of the integrity and structural changes of joint cartilage of the knee. The goal of the present study is to determine the site of early cartilaginous lesions in adults with non-traumatic knee pain. METHODS: 3-T MRI examinations of 200 asymptomatic knees with standard and three-dimensional double-echo steady-state (3D-DESS) cartilage-specific sequences were prospectively studied for early degenerative lesions of the tibiofemoral joint. Lesions were classified and mapped using the modified Outerbridge and modified International Cartilage Repair Society classifications. RESULTS: A total of 1437 lesions were detected: 56.1% grade I, 33.5% grade II, 7.2% grade III and 3.3% grade IV. Cartographically, grade I lesions were most common in the anteromedial tibial areas; grade II lesions in the anteromedial L5 femoral areas; and grade III in the centromedial M2 femoral areas. CONCLUSION: 3-T MRI with standard and 3D-DESS cartilage-specific sequences demonstrated that areas predisposed to early osteoarthritis are the central, lateral and ventromedial tibial plateau, as well as the central and medial femoral condyle. ADVANCES IN KNOWLEDGE: In contrast with previous studies reporting early cartilaginous lesions in the medial tibial compartment and/or in the medial femoral condyle, this study demonstrates that, regardless of grade, lesions preferentially occur at the L5 and M4 tibial and L5 and L2 femoral areas of the knee joint.

In vivo compatibility of Dynesys(®) spinal implants: a case series of five retrieved periprosthetic tissue samples and corresponding implants.

PURPOSE: To determine whether particulate debris is present in periprosthetic tissue from revised Dynesys(®) devices, and if present, elicits a biological tissue reaction. METHODS: Five Dynesys(®) dynamic stabilization systems consisting of pedicle screws (Ti alloy), polycarbonate-urethane (PCU) spacers and a polyethylene-terephthalate (PET) cord were explanted for pain and screw loosening after a mean of 2.86 years (1.9-5.3 years). Optical microscopy and scanning electron microscopy were used to evaluate wear, deformation and surface damage, and attenuated total reflectance Fourier transform infrared spectroscopy to assess surface chemical composition of the spacers. Periprosthetic tissue morphology and wear debris were determined using light microscopy, and PCU and PET wear debris by polarized light microscopy. RESULTS: All implants had surface damage on the PCU spacers consistent with scratches and plastic deformation; 3 of 5 exhibited abrasive wear zones. In addition to fraying of the outer fibers of the PET cords in five implants, one case also evidenced cord fracture. The pedicle screws were unremarkable. Patient periprosthetic tissues around the three implants with visible PCU damage contained wear debris and a corresponding macrophage infiltration. For the patient revised for cord fracture, the tissues also contained large wear particles (>10 µm) and giant cells. Tissues from the other two patients showed comparable morphologies consisting of dense fibrous tissue with no inflammation or wear debris. CONCLUSIONS: This is the first study to evaluate wear accumulation and local tissue responses for explanted Dynesys(®) devices. Polymer wear debris and an associated foreign-body macrophage response were observed in three of five cases.

Spine Tango annual report 2012.

PURPOSE: Since the Spine Tango registry was founded over a decade ago it has become established internationally. An annual report has been produced using the same format as the SWEspine group to allow for first data comparisons between the two registries. METHODS: Data was captured with the latest generation of surgery and follow-up forms. Also, the Core Outcome Measures Index (COMI) from interventions performed in the year 2012 with follow-up to June 2013 was analyzed. Groups of patients with the most common degenerative lumbar spine diseases and a single group of patients with degenerative cervical spine diseases were created. The demographics, risk factors, previous treatments, current treatment, short-term outcomes, patient satisfaction and complications were analyzed. Pre- and postoperative pain and function scores were derived from the COMI. RESULTS: About 6,500 procedures were captured with Spine Tango in 2012. The definitions and composition of all the degenerative groups could not completely be matched between the two registries with the consequence that the age and sex distributions were partially different. Preoperative pain levels were similar. The short-term outcomes available did not allow for evaluation of the final result of surgical intervention. This will be possible with the longer term data in the next annual report. There was a distinct disparity in reported complication rates between surgeons and patients. CONCLUSIONS: This is a valuable first step in creating comparable reports for SWEspine and Spine Tango. The German spine registry may be able to collaborate in the future because of similar items and data structure as Spine Tango. There needs to be more work on understanding the harmonization of the different degenerative subgroups. The Spine Tango report is weakened by the short and incomplete follow-up. The visual presentation of data may be a useful model for aiding decision making for surgeons and patients in the future.