[Clinical studies in trauma surgery and orthopedics: read, interpret and implement]. / Klinische Studien in Unfallchirurgie und Orthopädie: lesen, interpretieren und umsetzen.

Informative, participatory clinical decision-making needs to combine both skills and expertise as well as current scientific evidence. The flood of digital information makes it difficult in everyday clinical practice to keep up to date with the latest publications. This article provides assistance for coping with this problem. A basic understanding of prior and posterior probabilities as well as systematic error (bias) makes it easier to weigh up the benefits and risks, e.g. of a (surgical) intervention compared to a nonsurgical treatment. Randomized controlled trials (RCT, with all modern modifications) deliver undistorted results but in orthopedic and trauma surgery can lead to a heavily selected nonrepresentative sample and the results must be confirmed or refuted by further, independent RCTs. Large-scale observational data (e.g. from registries) can be modelled in a quasi-experimental manner and accompany RCTs in health technology assessment.

Mesenchymal stem cells from osteoporotic patients reveal reduced migration and invasion upon stimulation with BMP-2 or BMP-7.

Fractures to the osteoporotic bone feature a delay in callus formation and reduced enchondral ossification. Human mesenchymal stem cells (hMSC), the cellular source of fracture healing, are recruited to the fracture site by cytokines, such as BMP-2 and BMP-7. Aim of the study was to scrutinize hMSC for osteoporosis associated alterations in BMP mediated migration and invasion as well as in extracellular matrix (ECM) binding integrin expression. HMSC were isolated from 18 healthy or osteoporotic donors. Migration was assessed using a collagen IV coated micro-slide linear gradient chamber and time-lapse microscopy. Invasion was analyzed utilizing an ECM coated transmembrane invasion assay. Quantitative real-time RT PCR was performed for the ECM binding integrins α1, α2, α3, α4, α5, α11, αv and ß1. HMSC from osteoporotic patients showed a significant increase of migration upon BMP-2 or FCS stimulation, as well as a significant increase of invasion upon BMP-2, BMP-7 or FCS stimulation. Nevertheless, the migration and invasion capacity was significantly decreased compared to healthy controls. Out of all integrins analyzed, collagen binding integrin α2 was significantly downregulated in hMSC from osteoporotic patients. In conclusion, we here demonstrate for the first time osteoporosis associated alterations in BMP mediated hMSC recruitment. These findings may underlie the reduced healing of osteoporotic fractures. Nevertheless, the maintained migration and invasion response upon BMP stimulation illustrates the therapeutic potential of these clinically approved substances in the treatment of osteoporotic fractures. Another therapeutic target may be the downregulation of the collagen binding integrin α2 in hMSC from osteoporotic patients.

Pathologic fracture of the distal radius in a 25-year-old patient with a large unicameral bone cyst.

BACKGROUND: Distal radius fractures (DRF) are often referred to as osteoporosis indicator fractures as their incidence increases from age 45. In the group of young adults, distal radius fractures normally result from high-energy trauma. Wrist fractures in young patients without adequate trauma thus raise suspicion of a pathologic fracture. In this report we present the case of a fractured unicameral bone cyst (UBC) at the distal radius in a young adult.To the author's best knowledge, this is the first detailed report in an UBC at the distal radius causing a pathologic DRF in an adult patient. CASE PRESENTATION: A 25-year-old otherwise healthy male presented to our Emergency Department after a simple fall on his right outstretched hand. Extended diagnostics revealed a pathologic, dorsally displaced, intra-articular distal radius fracture secondary to a unicameral bone cyst occupying almost the whole metaphysis of the distal radius. To stabilize the fracture, a combined dorsal and volar approach was used for open reduction and internal fixation. A tissue specimen for histopathological examination was gathered and the lesion was filled with an autologous bone graft harvested from the ipsilateral femur using a reamer-irrigator-aspirator (RIA) system. Following one revision surgery due to an intra-articular step-off, the patient recovered without further complications. CONCLUSIONS: Pathologic fractures in young patients caused by unicameral bone cysts require extended diagnostics and adequate treatment. A single step surgical treatment is reasonable if fracture and bone cyst are treated appropriately. Arthroscopically assisted fracture repair may be considered in intra-articular fractures or whenever co-pathologies of the carpus are suspected.

The influence of knee position on ankle dorsiflexion - a biometric study.

BACKGROUND: Musculus gastrocnemius tightness (MGT) can be diagnosed by comparing ankle dorsiflexion (ADF) with the knee extended and flexed. Although various measurement techniques exist, the degree of knee flexion needed to eliminate the effect of the gastrocnemius on ADF is still unknown. The aim of this study was to identify the minimal degree of knee flexion required to eliminate the restricting effect of the musculus gastrocnemius on ADF. METHODS: Bilateral ADF of 20 asymptomatic volunteers aged 18-40 years (50% female) was assessed prospectively at six different degrees of knee flexion (0°, 20°, 30°, 45°, 60°, 75°, Lunge). Tests were performed following a standardized protocol, non weightbearing and weightbearing, by two observers. Statistics comprised of descriptive statistics, t-tests, repeated measurement ANOVA and ICC. RESULTS: 20 individuals with a mean age of 27 ± 4 years were tested. No significant side to side differences were observed. The average ADF [95% confidence interval] for non weightbearing was 4° [1°-8°] with the knee extended and 20° [16°-24°] for the knee 75° flexed. Mean weightbearing ADF was 25° [22°-28°] for the knee extended and 39° [36°-42°] for the knee 75° flexed. The mean differences between 20° knee flexion and full extension were 15° [12°-18°] non weightbearing and 13° [11°-16°] weightbearing. Significant differences of ADF were only found between full extension and 20° of knee flexion. Further knee flexion did not increase ADF. CONCLUSION: Knee flexion of 20° fully eliminates the ADF restraining effect of the gastrocnemius. This knowledge is essential to design a standardized clinical examination assessing MGT.

Long-term functional outcomes (median 10 years) after locked plating for displaced fractures of the proximal humerus.

BACKGROUND: Locked plating has become an accepted treatment for displaced fractures of the proximal humerus. However, to our knowledge, long-term outcomes have not been reported. METHODS: Between February 2002 and March 2004, 121 patients with displaced proximal humeral fractures were treated by open reduction and locking plate fixation. Forty-three patients were available for 10-year (95% confidence interval [CI], 9.8-10.1) follow-up, including Constant score (CS), Disabilities of the Arm, Shoulder and Hand score, and Short Form 36 questionnaire. RESULTS: Of 43 patients (72% women; mean age at time of fracture repair, 58.2 years; 95% CI, 54.2-62.2), the absolute CS 10 years after surgery was 75.3 (95% CI, 69.2-81.4). The normalized CS was 88.4 (95% CI, 81.7-95.1), and the CS in percentage to the contralateral side (%CS) was 83.7 (95% CI, 78.5-88.9). In contrast, at 1 year, the CS was 73.9 (95% CI, 67.8-80.2, P = .774), the normalized CS was 87.2 (95% CI, 80.4-94.0; P = .765), and the %CS was 78.7 (95% CI, 71.5-85.8; P = .355). The CS at 10 years correlated with the CS at 1 year after surgery (r = 0.460; P < .01) and with patient gender (r = -0.424; P < .01), and it strongly correlated with patient age (r = -0.545; P < .001). CONCLUSIONS: Ten years after locked plating of displaced proximal humeral fractures, patients show good to excellent outcomes in the majority of cases with no relevant decline compared with the shoulder function 1 year after surgery. However, poor long-term outcome is seen in 16% of patients and relates to a low CS 1 year after surgery. Thus, patients developing poor long-term outcomes may be identified at an earlier stage.

Prepatellar and olecranon bursitis: literature review and development of a treatment algorithm.

PURPOSE: Olecranon bursitis and prepatellar bursitis are common entities, with a minimum annual incidence of 10/100,000, predominantly affecting male patients (80 %) aged 40-60 years. Approximately 1/3 of cases are septic (SB) and 2/3 of cases are non-septic (NSB), with substantial variations in treatment regimens internationally. The aim of the study was the development of a literature review-based treatment algorithm for prepatellar and olecranon bursitis. METHODS: Following a systematic review of Pubmed, the Cochrane Library, textbooks of emergency medicine and surgery, and a manual reference search, 52 relevant papers were identified. RESULTS: The initial differentiation between SB and NSB was based on clinical presentation, bursal aspirate, and blood sampling analysis. Physical findings suggesting SB were fever >37.8 °C, prebursal temperature difference greater 2.2 °C, and skin lesions. Relevant findings for bursal aspirate were purulent aspirate, fluid-to-serum glucose ratio <50 %, white cell count >3,000 cells/µl, polymorphonuclear cells >50 %, positive Gram staining, and positive culture. General treatment measures for SB and NSB consist of bursal aspiration, NSAIDs, and PRICE. For patients with confirmed NSB and high athletic or occupational demands, intrabursal steroid injection may be performed. In the case of SB, antibiotic therapy should be initiated. Surgical treatment, i.e., incision, drainage, or bursectomy, should be restricted to severe, refractory, or chronic/recurrent cases. CONCLUSIONS: The available evidence did not support the central European concept of immediate bursectomy in cases of SB. A conservative treatment regimen should be pursued, following bursal aspirate-based differentiation between SB and NSB.

Position of polyaxial versus monoaxial screws in locked plating for proximal humeral fractures: analysis of a prospective randomized study.

BACKGROUND: Aim of the study was to compare the chosen position of polyaxial locking screws with the position of monoaxial screws in the humeral head of proximal humeral fractures treated by locked plating. METHODS: In a prospective randomized observational study, 124 consecutive patients (mean age 70.9±14.8 years) sustaining a displaced proximal humeral fracture were treated with either monoaxial or polyaxial screw-inserted locking plate fixation. The chosen positions of locking screws were identified from standardized postoperative radiographs in anteroposterior and outlet-view, with regard to a regional mapping of the humeral head. RESULTS: In monoaxial locking technique, a mean of 6 screws purchased the humeral head (95% CI 5.1-6.2), and in polyaxial locking technique, a mean of 4 screws (95% CI 3.3-4.5), respectively. Screws were placed in the regions superolateral: monoaxial 24.8%, polyaxial 20.7% (p=0.49); superomedial: monoaxial 21.9%, polyaxial 20.0% (p=0.433); inferolateral: monoaxial 32.5%, polyaxial 35.0% (p=0.354); inferomedial: monoaxial 20.8%, polyaxial 24.2% (p=0.07), superoposterior: monoaxial 45.5%, polyaxial 30.8% (p=0.57); superoanterior: monoaxial 4.4%, polyaxial 8.3% (p=0.33); inferoposterior: monoaxial 22.5%, polyaxial 29.8% (p=0.49) and inferoanterior: monoaxial 27.5%, polyaxial: 31.2% (p=0.09). CONCLUSION: The chosen screws' position in monoaxial and polyaxial locking plate fixation of displaced proximal humeral fractures do not differ significantly. However, loss of fixation is observed more frequently if the fixation did not include at least one screw within the superoposterior region of the humeral head, suggesting that a screw purchasing the superoposterior region is beneficial in locked plating of proximal humeral fractures. LEVEL OF EVIDENCE: Treatment Study, Level II.