Cryotherapy is often applied after injuries of synovial joints. Although positive clinical effects on periarticular swelling and pain are well known, the effects on molecular processes of cartilage and synovial cells remained largely unknown so far. Therefore, the hypothesis was tested that hypothermia alleviates the synovial reaction and prevents chondrocyte death as well as cartilage destructive processes after blunt trauma. Human articular cartilage and synovial tissue was obtained with informed consent from patients undergoing knee joint replacement. Cartilage explants from macroscopically intact cartilage were impacted by a drop-tower apparatus with defined energy (0.59J) and cultivated for 24h or 7d at following temperature conditions: 2h, 16h or throughout at 27°C and afterwards or throughout at 37°C. Furthermore, human fibroblast-like synoviocytes (FLS) were stimulated with conditioned medium from traumatized cartilage (t-CM) and cultivated as indicated above up to 4d. Effects of hypothermia were evaluated by live/dead assay, gene expression (RQ-PCR), and type II collagen synthesis/cleavage as well as release of MMP-2, MMP-13 and IL-6 on protein level (ELISA, gelatin zymography). Statistical analysis was performed by 2-way ANOVA. The experimental study was performed in the research laboratory of the Orthopedic Department, University Hospital Ulm, Germany. Hypothermic treatment significantly improved chondrocyte viability 7d after blunt cartilage trauma (2h: p=0.016; 16h: p=0.036; throughout: p=0.039). 2h posttraumatic hypothermia attenuated expression of MMP-13 (m-RNA: p=0.012; protein: p=0.024). While type II collagen synthesis was significantly increased after 16h hypothermia, MMP-13 expression (mRNA: p=0.003; protein: p<0.001) and subsequent cleavage of type II collagen (p=0.049) were inhibited. Continuous hypothermia for 7d further significantly suppressed MMP release (proMMP-2, active MMP-2 and MMP-13) and type II collagen breakdown. On day 4 t-CM stimulated FLS revealed significantly suppressed gene expression of matrix-destructive enzymes (16h: ADAMTS-4; throughout: ADAMTS-4, MMP-3, MMP-13) and by trend reduced IL-6 expression in case of 16h or continuous hypothermia. Overall, hypothermia for only 2h and/or 16h after blunt cartilage trauma exhibited significant cell- and matrix-protective effects and promoted anabolic activity of surviving chondrocytes. Expression of matrix-destructive enzymes by FLS stimulated with Danger Associated Molecular Patterns (DAMPs) released from traumatized cartilage was attenuated by more prolonged hypothermia. These findings suggest that an optimized cryotherapy management after cartilage trauma might have the potential to ameliorate early molecular processes usually associated with the pathogenesis of posttraumatic osteoarthritis.
This study aims to compare the gait pattern of patients operated with a TKA versus a normal population in order to evaluate if the excellent function of TKA reported in the literature corresponds to objectively measured parameters. 20 patients operated of TKA with a follow up >
1 year, all patients rated with a very good functional result (Knee Society Knee score >
85/100 – VAS <
= 1/10) were compared with a group of 20 “ normal” persons. The study was blind: the examiner did not know whether the person was a normal, or which knee was operated. The test consisted in an 11 meters walk, on an AMTI force platform; the movements of the body were recorded with 6 IR cameras and analysed with the “Motion Analysis” software. The implant was a mobile bearing AP stabilised knee. The measured parameters were kinematic : speed, step length, flexion angle, duration of stance /WB phase and dynamic : flexion/extension, varus/valgus, internal/ external moments and resultant force direction. When matched with age and BMI, all kinematic parameters of the TKA group are equal to that of the normals. However, dynamic parameters differ significantly between both groups: At the end of stance phase and heel strike the operated patients have a lack of extension of 10° despite a clinical measurement of full extension (0°) In the frontal plane, all patients exhibited a valgus walking pattern but the mechanical axis measured on long standing radiographs was 180°+/−1°. In the horizontal plane, all operated patients had an external rotation of +8° compared to the normals. Despite excellent clinical scores and radiologic positioning, gait analysis demonstrates important dynamic differences between the TKA and the normal group. The extension lag at heel strike may be related to either quad weakness, or an insufficient extension gap at surgery; The valgus resultant pattern occurs despite a perfect alignment of the mechanical axis (180°) on the operated patients: this rises the question whether this alignment is the goal or if an undercorrection would be more physiologic. External rotation is superior to the normal group : it is in relation with the external rotation of the femoral and tibial components. Conclusion. Gait analysis of the TKA group of patients compared to normal demonstrates important dynamic differences in relation with the surgical positioning of the implant.
The aim of the study was to compare mortalitiy and complication rate after operative treatment of pertrochanteric fractures with primary cemented arthroplasty, dynamic hip screw (DHS) or proximal femoral nail (PFN). 283 patients, which were treated betwen 1992 and 2005 for pertrochanteric femoral fractures, except pathologic fractures and a minimum age of sixty years were included. 132 of these 283 patients were treated by primary arthroplasty. Up to the end of 1999 all unstable fractures were treated by primary total hip replacement. In the year 2000 the PFN was introduced and only patients with severe osteoarthritis and osteoporosis received primary arthroplasty. I possible, more stable fractures were treated with a DHS. One year mortality was chosen as main indicator as it depends on the surgical trauma as well as the rapid return to preinjury activity and further complications. A one year period was chosen as the mortality ratio approaches that of an age matched reference population after this interval. Influencing cofactors were eliminated by stepwise logistic regression analysis. It was shown that restoration of the preoperative ambulatory level correlated with survival rate after one year. As elderly patients are often unable to cooperate with partial weight bearing, the primary stability of the device is crucial to allow early mobilisation Mortality was significantly influenced by age, gender and comorbidities but not by fracture classification. One-year mortality was significantly higher for primary total hip replacement (34.2 %) than for internal fixation (DHS: 18.4 %; PFN 21.4 %) and hemiarthroplasty (13.3 %). Since the PFN and hemiarthroplasty were introduced the over all mortality was reduced from 29 % to 18 %.
