Incidence of postoperative complications in patellar fractures related to different methods of osteosynthesis procedures - a retrospective cohort study.

BACKGROUND: Patellar fractures have a comparatively low incidence compared to all fracture frequencies of the musculoskeletal system. However, surgical management is crucial to prevent postoperative complications that affect the knee joint. The purpose of the present study was to evaluate the incidence of postoperative complications and onset of postoperative osteoarthritis related to the chosen technique of patellar fracture management. METHODS: In a retrospective cohort study consecutive managed, isolated patella fractures were reviewed for demographic data, trauma mechanism, patella fracture type, fixation technique and postoperative complications. The results were documented radiographically and clinically and analysed statistically. The reporting followed the STROBE guidelines. RESULTS: A total of 112 patients were eligible for data evaluation. Surgical management of comminuted patellar fractures with small fragment screws showed significant fewer postoperative complications compared to other fixation techniques (8%, p < 0.043). The incidence of posttraumatic infection was significantly higher following the hybrid fixation technique with cannulated screws and tension wire than following the other analysed techniques (p = 0.024). No postoperative wound infection was observed after screw fixation or locking plate fixation. Symptomatic hardware was most frequently seen after tension-band fixation. Onset of posttraumatic osteoarthritis was most often found after the hybrid fixation technique (55%). CONCLUSION: Surgical management of patellar fractures remains crucial but fracture fixation using plating systems or small fragment screws is least associated with postoperative complications. TRIAL REGISTRATION: Trial registration number (DRKS):00027894.

Evaluation of the influence of platelet-rich plasma (PRP), platelet lysate (PL) and mechanical loading on chondrogenesis in vitro.

The aim of this work is to investigate the capability of PRP as an adjuvant therapy to autologous chondrocyte implantation (ACI) in combination with multi-axial load with respect to cartilage regeneration. Articular cartilage shows poor repair capacity and therapies for cartilage defects are still lacking. Well-established operative treatments include ACI, and growing evidence shows the beneficial effects of PRP. Platelets contain numerous growth factors, among them transforming growth factor beta (TGF-ß). Dynamic mechanical loading is known to be essential for tissue formation, improving extracellular matrix (ECM) production. For our ACI model monolayer expanded human chondrocytes were seeded into polyurethane scaffolds and embedded in fibrin (hChondro), in PRP-Gel (PRP), or in fibrin with platelet lysate (PL), which was added to the media once a week with a concentration of 50 vol%. The groups were either exposed to static conditions or multi-axial forces in a ball-joint bioreactor for 1 h per day over 2 weeks, mimicking ACI under physiological load. The culture medium was collected and analyzed for glycosaminoglycan (GAG), nitrite and transforming growth factor beta 1 (TGF-ß1) content. The cell-scaffold constructs were collected for DNA and GAG quantification; the expression of chondrogenic genes, TGF-ß and related receptors, as well as inflammatory genes, were analyzed using qPCR. Loading conditions showed superior chondrogenic differentiation (upregulation of COL2A1, ACAN, COMP and PRG4 expression) than static conditions. PRP and PL groups combined with mechanical loading showed upregulation of COL2A1, ACAN and COMP. The highest amount of total TGF-ß1 was quantified in the PL group. Latent TGF-ß1 was activated in all loaded groups, while the highest amount was found in the PL group. Load increased TGFBR1/TGFBR2 mRNA ratio, with further increases in response to supplements. In general, loading increased nitrite release into the media. However, over time, the media nitrite content was lower in the PL group compared to the control group. Based on these experiments, we conclude that chondrogenic differentiation is strongest when simulated ACI is performed in combination with dynamic mechanical loading and PRP-gel or PL supplementation. An inflammatory reaction was reduced by PRP and PL, which could be one of the major therapeutic effects. Loading presumably can enhance the action of TGF-ß1, which was predominantly activated in loaded PL groups. The combination of load and PRP represents an effective and promising synergy concerning chondrocyte-based cartilage repair.

The tissue-renin-angiotensin-system of the human intervertebral disc.

Symptomatic intervertebral disc (IVD) degeneration accounts for significant socioeconomic burden. Recently, the expression of the tissue renin-angiotensin system (tRAS) in rat and bovine IVD was demonstrated. The major effector of tRAS is angiotensin II (AngII), which participates in proinflammatory pathways. The present study investigated the expression of tRAS in human IVDs, and the correlation between tRAS, inflammation and IVD degeneration. Human IVD tissue was collected during spine surgery and distributed according to principal diagnosis. Gene expression of tRAS components, proinflammatory and catabolic markers in the IVD tissue was assessed. Hydroxyproline (OHP) and glycosaminoglycan (GAG) content in the IVD tissue were determined. Tissue distribution of tRAS components was investigated by immunohistochemistry. Gene expression of tRAS components such as angiotensin-converting enzyme (ACE), Ang II receptor type 2 (AGTR2), angiotensinogen (AGT) and cathepsin D (CTSD) was confirmed in human IVDs. IVD samples that expressed tRAS components (n = 21) revealed significantly higher expression levels of interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 4 and 5 compared to tRAS-negative samples (n = 37). Within tRAS-positive samples, AGT, matrix-metalloproteinases 13 and 3, IL-1, IL-6 and IL-8 were more highly expressed in traumatic compared to degenerated IVDs. Total GAG/DNA content of non-tRAS expressing IVD tissue was significantly higher compared to tRAS positive tissue. Immunohistochemistry confirmed the presence of AngII in the human IVD. The present study identified the existence of tRAS in the human IVD and suggested a correlation between tRAS expression, inflammation and ultimately IVD degeneration.

The effect of sclerotherapy and prolotherapy on chronic painful Achilles tendinopathy-a systematic review including meta-analysis.

Chronic painful Achilles tendinopathy (AT) is a common disorder among athletes. Sclerotherapy (ST) and prolotherapy (PT) are two promising options among the numerous other conservative therapies. As their efficacy and potential adverse effects (AE) are still unclear, we systematically searched, analyzed, and synthesized the available literature on ST and PT for treating AT. Electronic databases, Google Scholar and articles' reference lists were searched according to PRISMA guidelines. Eligibility criteria were set up according to the PICOS-scheme including human and animal studies. Three authors independently reviewed the results and evaluated methodological quality (Coleman Methodology Score and Cochrane Risk of Bias Assessment). The initial search yielded 1104 entries. After screening, 18 articles were available for qualitative synthesis, six of which were subjected to meta-analysis. The mean Coleman Score of the 13 human studies was 50. Four RCTs were ranked as having a low risk of selection bias. Three of those reported a statistically significant drop in the visual analog scale (VAS) score, one a significant increase in the VISA-A Score. 12 of 13 human studies reported positive results in achieving pain relief and patient satisfaction, whereas only one study's finding differed. Meta-analysis revealed an unambiguous result in favor of the intervention (weighted mean difference D=-4.67 cm, 95% CI -5.56 to -3.76 cm [P<.001]). Only one serious AE and two minor AEs were reported in the entire literature. This systematic review suggests that ST and PT may be effective treatment options for AT and that they can be considered safe. Long-term studies and RCTs are still needed to support their recommendation.

German translation and content validation of the OSTRC Questionnaire on overuse injuries and health problems.

OBJECTIVE: The aim of this study was to translate, culturally adapt and validate the Oslo Sports Trauma Research Centre (OSTRC) Questionnaire on Health Problems into the German context. METHODS: A slightly modified back-translation method was used to translate the questionnaire. Validation was done in 24 high-level Paralympic athletes followed over 20 consecutive weeks. RESULTS: The translated version of the questionnaire showed a very high internal consistency and good test-retest reliability (Cronbach's α 0.92, intraclass correlation coefficient 0.91). Additionally, we observed high acceptance and compliance from our cohort of athletes, whose mean weekly response rate was 91.5%. Overall, 114 training days were lost because of illness or injury within the 20 weeks and, on average, 5 athletes per week (20.8%) reported health problems. CONCLUSIONS: This study demonstrates that the translated German version of the OSTRC Questionnaire is a reliable and valid tool with high internal consistency for the medical monitoring of German athletes. The OSTRC-G now offers the opportunity for a continued surveillance of high-level German athletes.

Biomechanical investigation of a minimally invasive posterior spine stabilization system in comparison to the Universal Spinal System (USS).

BACKGROUND: Although minimally invasive posterior spine implant systems have been introduced, clinical studies reported on reduced quality of spinal column realignment due to correction loss. The aim of this study was to compare biomechanically two minimally invasive spine stabilization systems versus the Universal Spine Stabilization system (USS). METHODS: Three groups with 5 specimens each and 2 foam bars per specimen were instrumented with USS (Group 1) or a minimally invasive posterior spine stabilization system with either polyaxial (Group 2) or monoaxial (Group 3) screws. Mechanical testing was performed under quasi-static ramp loading in axial compression and torsion, followed by destructive cyclic loading run under axial compression at constant amplitude and then with progressively increasing amplitude until construct failure. Bending construct stiffness, torsional stiffness and cycles to failure were investigated. RESULTS: Initial bending stiffness was highest in Group 3, followed by Group 2 and Group 1, without any significant differences between the groups. A significant increase in bending stiffness after 20'000 cycles was observed in Group 1 (p = 0.002) and Group 2 (p = 0.001), but not in Group 3, though the secondary bending stiffness showed no significant differences between the groups. Initial and secondary torsional stiffness was highest in Group 1, followed by Group 3 and Group 2, with significant differences between all groups (p ≤ 0.047). A significant increase in initial torsional stiffness after 20'000 cycles was observed in Group 2 (p = 0.017) and 3 (p = 0.013), but not in Group 1. The highest number of cycles to failure was detected in Group 1, followed by Group 3 and Group 2. This parameter was significantly different between Group 1 and Group 2 (p = 0.001), between Group 2 and Group 3 (p = 0.002), but not between Group 1 and Group 3. CONCLUSIONS: These findings quantify the correction loss for minimally invasive spine implant systems and imply that unstable spine fractures might benefit from stabilization with conventional implants like the USS.