Correlation of head screw lengths in proximal humerus nailing: a CT-based study on 289 cases.

INTRODUCTION: Nailing of the proximal humerus is an established method for the treatment of proximal humerus fractures. Choice of the correct length for potentially four proximal locking screws is essential for postoperative outcome. Due to positioning of the patient, intraoperative determination of the correct length of the anteroposterior (AP) screw with the x-ray beam is particularly challenging even for experienced surgeons. We hypothesized that there would be a correlation between the projected lengths of the different proximal locking screws and therefore the length of the AP-screw could be determined based on the three lateromedial (LM) screws. MATERIALS AND METHODS: In this retrospective study (level of evidence: III) CT-scans of shoulders of 289 patients were 3D reconstructed with the program Horos. Using the manufacturer Stryker's instructions, the four proximal locking screws of the T2 Humeral Nail system were reproduced in the 3D reconstructed shoulders. The length of the AP-screw was correlated with the lengths of the LM-screws by Linear Regression and Multiple Linear Regression. RESULTS: The results of this study showed that the lengths of proximal locking screws in proximal humeral nailing correlated significantly with each other. Based on the given data, a formula could be established to calculate the length of the AP-screw based on the lengths of the LM-screws with a probability of 76.5%. CONCLUSIONS: This study was able to show that the length of the AP-screw could be determined from the intraoperatively measured lengths of the LM-screws. As our findings base on measurements performed in CT scans, clinical studies are needed to support our data.

Influence of the inclination angle of the S1 pedicle on screw malposition and operative revision in percutaneous iliosacral screw fixation of posterior pelvic ring fractures.

INTRODUCTION: Due to aging society, osteoporotic posterior ring fractures of the pelvis are gaining importance. Percutaneous iliosacral screw fixation can reduce pain if conservative therapy is not sufficient. One of the surgical complications is the malposition of the screws in neuroforamen. The aim of this study is to correlate the measured pedicle angle with the screw position in postoperative CT scans. MATERIALS AND METHODS: In this retrospective study (level of evidence: III), 97 patients with posterior ring fractures were treated with 137 percutaneous iliosacral screws. The inclination angles of the S1 pedicle were measured in the preoperative pelvic CT scan of each patient. Patients were divided up into pedicle angles from 10 - 19.9° (Group 1), 20 - 29.9° (Group 2), 30 - 39.9° (Group 3) and 40 - 49.9° (Group 4). We correlated the pedicle inclination angle to radiologically described screw position in the L5/S1 neuroforamen and the need for revision because of screw malposition. RESULTS: A total of 10 pedicle inclination angles were from 10 - 19.9° (7.3%), 96 from 20 - 29.9° (70.1%), 28 from 30 - 39.9° (20.4%) and three from 40 - 49.9° (2.2%). Of the 137 screws used, 19 were intraforaminal (13.9%). There were no intraforaminal screws in the Group 1, eight in Group 2, 10 in Group 3 and one in Group 4. Five of the screws needed revision (3,6%). There were no revisions in Groups 1 and 4, two in Group 2 and three in Group 3. Groups 3 and 4 had a higher percentage of intraforaminal screw positions. Patients with steeper angles S1 pedicles showed a significantly higher probability of intraforaminal screw location and revision (p<0.01). DISCUSSION: Complications such as intraforaminal screw position and revision surgery are more frequent in patients with steeper S1 pedicles, making this a detrimental prognostic marker.

Rare implant-specific complications of the MoPyC radial head prosthesis.

BACKGROUND: According to currently available data, the clinical short-term results of the MoPyC radial head prosthesis (Bioprofile, Tornier, Montbonnot-Saint-Martin, France) seem favorable. However, we have encountered several implant-specific complications in recent years. Hence, this case series reports rare complications after radial head arthroplasty with the MoPyC prosthesis to make surgeons aware of their existence and to provide information about the underlying cause and possible salvage strategies. METHODS: A retrospective chart review from 2011 to 2016 was conducted to identify all adult patients with a minimum 2-year follow-up who underwent or were referred after radial head arthroplasty with the MoPyC radial head prosthesis and experienced implant-related complications. RESULTS: Five patients with 7 implant-related complications were found. One patient experienced breakage of the pyrocarbon head. In another patient, breakage of the stem and-after revision surgery-partial breakage were observed. Disassembly of the prosthesis was seen in 1 case. Extensive periprosthetic stress shielding was seen in 3 patients resulting in symptomatic loosening (1), periprosthetic radial neck fracture (1), and stem migration (1). CONCLUSIONS: Whereas clinical short-term results of the MoPyC radial head prosthesis are satisfactory, rare implant-related complications can occur. Surgeons should be aware of these complications as they may lead to a poor outcome.

Percutaneous iliosacral screw fixation after osteoporotic posterior ring fractures of the pelvis reduces pain significantly in elderly patients.

INTRODUCTION: Osteoporotic posterior ring fractures of the pelvis are common injuries in the elderly, but the treatment of these fractures still remains controversial. Percutaneous iliosacral screw fixation is one surgical option if conservative treatment cannot provide sufficient pain reduction. The aim of this study is to provide short-term results of elderly patients with percutaneous screw fixation. METHODS: 30 patients with posterior ring fractures were treated between 12/2009 and 01/2014 with percutaneous iliosacral screw fixation. Patients' mean age was 78.4 years. Concerning short-term outcome, we focused on initial pain level and postoperative pain reduction together with intra- and postoperative complications. RESULTS: The average hospital stay was 23.7 days, with surgical treatment performed after an average of 9.2 days. 90% of our patients were female. All 30 patients had a lower level of pain at discharge compared with admission or immediately prior to surgery. The difference in pain level at admission compared with the pain level upon discharge showed a mean reduction from 6.8 to 1.8 with a statistically significant change (P≤0.001). 24 of 30 patients had no registered complications, one screw malpositioning with postoperative nerve irritation occurred. DISCUSSION: Conventional percutaneous iliosacral screw fixation is a successful operative treatment for elderly patients with persistent lower back pain after unstable posterior ring fractures of the pelvis. Intra- and postoperative complications are rare, so this treatment can be regarded as a safe procedure. LEVEL OF EVIDENCE: IV (retrospective study).

Presentation of the vascular supply of the proximal ulna using a sequential plastination technique.

PURPOSE: The purpose of this study was to demonstrate the peri- and intraosseous vascular supply of the proximal ulna. METHODS: Eleven fresh human cadaveric elbows were sequentially plastinated beginning with arterial injection, followed by block and secondary slice plastination of the whole elbow. With this technique, we obtained completely transparent cadaveric slices in which the peri- and intraosseous vascular architecture could be studied. RESULTS: Proximal ulna vascularization is due to an arterial network: a superior and inferior collateral ulnar artery and the profunda brachial artery climbing to the olecranon from proximal. An anterior artery and a posterior recurrent artery climb up distally to the medial parts of the ulna and an interosseous recurrent artery is responsible for the lateral and posterolateral proximal part of the ulna. The intraosseous vascularization is due to directly penetrating branches out of the posterior recurrent ulnar artery and a vascular plexus at the olecranon tip. In addition, we saw a major distal bone penetration branch coming from the recurrent posterior artery, climbing intraosseously without junction to the proximal penetrating branches. CONCLUSION: The peri- and intraosseous vascularization of the proximal ulna was shown. A transitional zone of the intraosseous vascularization of the proximal ulna was detected.

Treatment of unstable elbow dislocations with hinged elbow fixation-subjective and objective results.

BACKGROUND: The aim of this study was to provide subjective and objective results of surgical treatment of unstable elbow dislocations with the hinged external fixation technique. METHODS: Twenty-six patients were available for re-examination after treatment. Parameters used to quantify the subjective functional results were the Mayo Elbow Performance Score, the shortened Disabilities of the Arm, Shoulder, and Hand questionnaire, and the stability of the elbow joint. In addition, we measured the medial and lateral joint space by varus and valgus stress ultrasound examinations of the elbow. RESULTS: The mean Mayo Elbow Performance Score was 93.5 (±8.3 standard deviation), and the shortened Disabilities of the Arm, Shoulder, and Hand questionnaire showed an average of 7.3 points (±8.9 standard deviation). We saw 18 patients with stable joints and 8 patients with slight instability. In the ultrasound stress test, we saw a significant difference of the affected joint under varus stress (7.8 ± 1.7 mm) compared with the healthy joint (5.8 ± 1.2 mm) laterally. Furthermore, medially the gap was significantly larger (4.8 ± 0.9 mm; treated elbow) than contralaterally under valgus stress (3.3 ± 0.7 mm) (P < .001). CONCLUSION: Closed reduction and hinged external fixation of unstable elbow dislocations resulted in good and very good results. We could identify a slight difference in the stability of the affected elbow compared with the contralateral side in all patients without clinical relevance.

Characterization of tumor-associated B-cell subsets in patients with colorectal cancer.

PURPOSE: A precise understanding of the mechanisms by which human immune cell subsets affect tumor biology will be critical for successful treatment of cancer using immunotherapeutic approaches. Recent evidence suggests that B cells can both promote and inhibit the development and progression of tumors. The aim of this study was to characterize the composition of the B-cell infiltrates in colorectal cancers (CRC) in order to gain further insight into the role of B cells in CRC. EXPERIMENTAL DESIGN: In this study we characterized B-cell subsets in primary tumors (n=38), metastases (n=6) and blood (n=46) of 51 patients with a diagnosis of CRC and blood of 10 healthy controls. B-cell subsets were analyzed by flow cytometry or immunohistochemistry. RESULTS: Peripheral blood of CRC patients contained a higher percentage of memory B cells than that of age-matched healthy controls. Furthermore, the percentage of B cells within tumors was higher than that in the peripheral blood of CRC patients while metastases were typically devoid of tumor-infiltrating B cells. Tumor-associated B cells were enriched for activated and terminally differentiated B cells. Relevant proportions of regulatory B cells could only be detected in advanced cancer and metastases. CONCLUSION: B cells constitute a significant proportion of the immune infiltrate in CRC. The B-cell infiltrate of primary CRC is characterized by an accumulation of terminally differentiated memory B cells or plasma cells suggestive of a specific immune response against the tumor. However advanced tumors and metastases are also infiltrated by a considerable number of regulatory B cells.

The bispecific immunoligand ULBP2-aCEA redirects natural killer cells to tumor cells and reveals potent anti-tumor activity against colon carcinoma.

NKG2D, an activating receptor expressed on NK cells and T cells, is critically involved in tumor immunosurveillance. In this study, we explored the potential therapeutic utility of the NKG2D ligand ULBP2 for the treatment of colon carcinoma. To this end we designed a fusion protein consisting of human ULBP2 and an antibody-derived single chain targeting the tumor carcinoembryonic antigen (CEA). The bispecific recombinant fusion protein re-directed NK cells towards malignant cells by binding to both, tumor cells and NK cells, and triggered NK cell-mediated target cell killing in vitro. Moreover, tumor growth was significantly delayed in a syngeneic colon carcinoma mouse model in response to immunoligand treatment. The anti-tumor activity could be attributed to the stimulation of immune cells with an elevated expression of the activation marker CD69 on NK, T and NKT cells and the infiltration of CD45+ immune cells into the solid tumor. In summary, it was demonstrated that immunoligands provide specific tumor targeting by NK cells and exert anti-tumor activity in vitro and in vivo. This technology represents a novel immunotherapeutic strategy for solid tumors with the potential to be further developed for clinical applications.

The ratio between dendritic cells and T cells determines whether prostaglandin E2 has a stimulatory or inhibitory effect.

Prostaglandin E2 has been shown to enhance the maturation, migration, and antigen-presenting capacity of DCs. It is therefore included in many maturation cocktails for the generation of monocyte-derived DCs. Paradoxically, PGE2 is also an important tumor-derived immunosuppressive factor and has inhibitory effects on DC differentiation and function. To further investigate these seemingly contradictory results we studied whether the DC:T cell ratio has an impact on the outcome of the interaction between PGE2-treated DCs and T cells. Surprisingly, at high DC:T cell ratios T cell proliferation was inhibited while at low ratios PGE2-treated DCs displayed enhanced T cell-stimulatory properties. The inhibitory function of PGE2-treated DCs depended primarily on the PGE2-induced induction of indoleamine 2,3-dioxygenase competence. In summary, we show that PGE2-treated DCs can have either an immunogenic or tolerogenic function depending on the DC:T cell ratio. This finding could explain the conflicting results regarding the influence of PGE2 on DC function.

Reconstruction of a Bryan and Morrey type I capitellar fracture in a sawbone model with four different fixation devices: an experimental study.

BACKGROUND: We evaluated 4 different fixation devices for the reconstruction of a standardised Bryan and Morrey capitellar shear fracture in a sawbone model. Outcome measurements were the quality of reduction, time for reconstruction and stability. METHODS: 80 standardised Bryan and Morrey type I fractures were created for 5 different orthopaedic surgeons in 80 sawbones. Each surgeon reconstructed 16 fractures with 2mm K-wires, 3mm Herbert screws, 2.7 mm AO screws and 2.2mm fine-threaded wires (Fragment Fixation System: FFS). 4 fractures were allocated to each method with a standardised reconstruction procedure. Quality of reduction and time for reconstruction were measured after definitive fixation. Biomechanical testing was performed using a shear loading model with the application of monocyclic or polycyclic stress to the reconstructed capitulum. RESULTS: There was no difference in the quality of reduction with the different fixation devices. Herbert and AO screw fixation was slower than the other implants (p<0.05). No difference in the time for reconstruction was observed with K-wires and FFS. Failure load was less for K-wires compared to FFS, Herbert screws and AO screws (p<0.05). With polycyclic loading, residual deformation was higher with K-wire reconstruction compared to FFS, Herbert screws and AO screws (p<0.05). CONCLUSION: When using four different fixation devices, the fixation of standardised Bryan and Morrey type I fractures in the sawbone model differs when it comes to the time needed for reduction, but not in the quality of reduction. Stability was the same for the implants used, except for the K-wires. There is no argument in favour one of the screw implants over another in clinical use.

Reconstruction of radial capitellar fractures using fine-threaded implants (FFS).

Fractures of the capitulum humeri are rare and challenging injuries to the elbow and outcome results are limited to case series, often with different fixation devices. This article aims to present 15 patients with a fracture of the capitulum humeri treated with the same implant, fine-threaded Kirschner wires (FFS). Besides range of motion and grip strength, outcome measurements include the following scores: the Mayo Elbow Performance index (MEPI); the American Shoulder and Elbow Surgeons' Elbow Assessment (ASES) Form; the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire; and the Broberg-Morrey score. Using the modified Bryan and Morrey classification, there were seven type-I injuries, three type-II, two type-III and three type-IV fractures. In addition to fractures of the capitellum, five patients were diagnosed with a complex ligamentous injury and three had suffered radial head fractures. After a minimum follow-up of 12 months, we obtained a range of motion in flexion and extension of 124° and a pro- and supination of 173°. The mean DASH showed 10.84 and the Broberg-Morrey score reached 90.8. ASES and MEPI scores were 91.5 and 90, respectively. The mean grip strength of the injured side was 217.9N versus 236.4N on the healthy side. The use of FFS for capitellar fractures of the humerus achieved good clinical results and these implants can be considered as a treatment option for this fracture entity.

Analysis of Tie2-expressing monocytes (TEM) in patients with colorectal cancer.

Tie2-expressing monocytes (TEM) promote tumor angiogenesis and growth in experimental cancer models. The role of TEM in cancer patients is unknown. We studied TEM in healthy volunteers and colorectal cancer (CRC) patients. Although TEM were detectable in the blood and tumor lesions of CRC patients, their frequency and functional phenotype showed no correlation with levels of angiopoietin-2 or vascular endothelial growth factor, microvessel density, tumor markers, tumor stage, or outcome of antiangiogenic therapy. These unexpected findings are at odds with murine tumor models and question the diagnostic or therapeutic value of TEM in human cancer.

Treatment of displaced proximal fifth metatarsal fractures using a new one-step fixation technique.

BACKGROUND: Fractures of the tuberosity of the fifth metatarsal are common after foot twisting injuries, and operative treatment is recommended in cases of displacement. The purpose of this study was to report the radiologic outcome and clinical results of displaced fractures of the tuberosity of the fifth metatarsal treated using fine-threaded K-wires (FFS). METHODS: In 3 years' time, in a total of 35 cases, patients had an initial fracture displacement of more than 2 mm for isolated extraarticular fractures and an involvement of the cuboidal joint surface of more than 30%. After 15 months to 60 months (mean, 30.6), 32 of these patients participated in a clinical follow-up examination and questionnaire according to a clinical rating system for midfoot fractures. Radiologic outcome measurements were the remaining postoperative intraarticular step off and the healing time. RESULTS: The mean midfoot scale score was 96.5 points. All the patients returned to prior activities after operative treatment. Seven patients reported minor pain during longer periods of walking. One patient with secondary wound healing experienced frequent pain. Radiologically, in 32 of 35 patients, there was a remaining step off of less than 1 mm and in three patients less than 3 mm. All fractures except one healed within the first 3 months to 6 months. CONCLUSION: Operative treatment of displaced proximal fifth metatarsal fractures using the FFS system leads to a good clinical and radiologic outcome. The FFS system provides a new treatment option for this fracture type.

Olecranon fracture fixation with a new implant: biomechanical and clinical considerations.

UNLABELLED: This study aims to describe the first clinical results in the treatment of dislocated olecranon fractures with 2.2-mm, fine-threaded wires with a washer. Furthermore, in the second part of the article, the stability of these new implants has been compared to standard tension band wiring in a sawbone model. PATIENTS: The radiological and clinical outcomes in 24 patients (mean age: 53.6 years) with 24 isolated Mayo type I and II fractures of the olecranon were evaluated in a prospective study after open reduction and internal fixation (ORIF) with a new fixation device (FFS; Orthofix). The quality of reduction with the implementation of 24 FFS constructions was compared with 24 tension band-wiring procedures performed by six different surgeons in a standard sawbone Mayo type IIa fracture model. Stability was tested in all constructs using a single cycle load to failure protocol (group I), cyclic loading for 300 cycles between 10 and 500 N (group II) and incremental sinusoidal loading from 10 to 200 N with an incremental increase of 10 N per cycle (group III) in a laboratory study. RESULTS: The Morrey elbow score was excellent in 23 patients and good in one patient, with mean DASH score of 1.6. No implant migration, secondary dislocation or nonunion was observed. In the sawbone model, the quality of reduction was the same with the FFS implants compared to the tension band wiring in the sawbone model. Here, bending moments in all three groups showed no significant difference, whereas displacement at failure was significantly greater in the tension band-wiring group at a single cycle load (p=0.017). CONCLUSION: Clinical results were comparable to tension band wiring and stability of the implants in the sawbone model was the same; thus, we conclude that the FFS technique can serve as an alternative treatment option for isolated olecranon fractures.

Efficient activation of autologous tumor-specific T cells: a simple coculture technique of autologous dendritic cells compared to established cell fusion strategies in primary human colorectal carcinoma.

Different technologies have been employed to deliver the whole spectrum of tumor antigens (TAs) to dendritic cells (DCs) to be presented to T cells. These include whole tumor RNA-transfected DCs, preparations of DCs loaded with tumor-derived apoptotic bodies or tumor cell lysates, and DC tumor cell fusions. Early clinical trials have been conducted using such techniques. The presented study was aimed to revisit the necessity of tumor cell manipulation in DC-based immunotherapy strategies for colorectal carcinoma. We investigated a simple coculture method of autologous monocyte-derived DCs and human primary colorectal carcinoma (pCC) in comparison with 2 well-described cell fusion strategies for the efficacy of uptake, processing and presentation of TAs to autologous T cells. Before coculture or fusion, pCC had been cryopreserved without further manipulation. Fluorescence microscopy and flow cytometry analyses of fluorescent dye labeled cells were used for monitoring engulfment of pCC by DCs. The coculture procedure resulted in a double positive cell fraction of up to 22% and thus was comparable to that observed after cell fusion. More important, DCs after coculture with autologous pCC induced significant tumor-specific interferon-gamma-producing autologous T cells in the same number of patients as DC/pCC fusions. Furthermore, tumor-specific major histocompatibility complex class I restricted cytotoxic T lymphocytes were generated by stimulation with DCs cocultured with pCC. In prior studies for human carcinomas coculture techniques were described to be inferior. In contrast, our data strongly suggest that at least for human pCC and autologous DCs this simple coculture method is similarly efficient compared to established fusion techniques.

Reconstruction of Mason type-III and type-IV radial head fractures with a new fixation device: 23 patients followed 1-4 years.

BACKGROUND: Treatment options in radial head fractures of Mason types III and IV range from open reduction and internal fixation (ORIF) to radial head resection with or without prosthetic replacement. PATIENTS: In a prospective study, the radiographic and clinical outcome was evaluated in 23 patients (age median 51 years) with 23 complex radial head fractures median 2 (1-4) years after ORIF using a new fixation device (FFS; Orthofix). 14 Mason type-III fractures with 2 concomitant olecranon fractures and 1 ulnar nerve lesion, and 11 type-IV fractures with 2 olecranon fractures and 2 fractures of the coronoid process were treated. 2 patients were lost to follow-up. In 7 cases of joint instability, an elbow fixator with motion capacity was applied after ORIF of the radial head. RESULTS: No radial head resection was necessary. No secondary dislocations or nonunion occurred. The Morrey elbow score was excellent in 8 and good in 4 Mason type-III fractures and excellent in 5, good in 3, and fair in 3 Mason type-IV fractures. INTERPRETATION: Reconstruction of comminuted radial head fractures can be performed with this device and radial head resection can be avoided.

Mechanical distraction for the treatment of posttraumatic stiffness of the elbow in children and adolescents. Surgical technique.

BACKGROUND: Elbow contracture is a recognized sequela of elbow injuries in children and adolescents, but previous studies of operative treatment with formal capsular release have demonstrated unpredictable outcomes and unfavorable results. METHODS: Over a period of five years, fourteen children and adolescents with a mean age of fourteen years who had posttraumatic stiffness of the elbow were managed according to a prospective protocol. Eleven patients had undergone a mean of three previous operative procedures before the index operation. After intraoperative distraction with an external fixator, there was a relaxation phase for six days followed by mobilization of the elbow joint under distraction in the fixator for a mean of seven weeks. Intraoperative range of motion under distraction reached a mean of 100 degrees . Open arthrolysis was not performed, but in four children impinging heterotopic bone was removed through a limited approach. Decompression of the ulnar nerve was performed in seven patients. RESULTS: The mean preoperative arc of total elbow motion was 37 degrees . The mean pronation was 46 degrees , and the mean supination was 56 degrees . After a mean duration of follow-up of thirty-four months, all patients but two had achieved an arc of motion of 100 degrees . The mean arc of flexion-extension was 108 degrees (range, 75 degrees to 130 degrees ). The mean range of pronation was 73 degrees (range, 20 degrees to 90 degrees ), and the mean range of supination was 75 degrees (range, 10 degrees to 90 degrees ). There were no pin-track infections or deep infections, and all elbows were stable. At the time of follow-up, three patients had radiographic evidence of humeroulnar degeneration. CONCLUSIONS: Closed distraction of the elbow joint with use of a monolateral external fixation frame with motion capacity yields more favorable results than other previously reported options for the treatment of posttraumatic elbow contractures in children and adolescents.

Treatment of bilateral elbow dislocation using external fixation with motion capacity: a report of 2 cases.

Bilateral elbow dislocation is a rare injury and only 11 cases are described in the literature, including 8 patients with isolated ligamentous and 3 patients with an additional osseous injury. We present 2 cases of bilateral posterior elbow dislocations treated with a bilateral hinged elbow fixator with motion capacity to allow for early physiotherapy. Both patients had a high-energy trauma with one who fell off a ladder from a 5 m height and the second from a mountain bike injury during off-road biking. All extremities were neurovascularly intact. In the operating room, severe instability was detected in all 4 elbows: after closed reduction in 3 elbows and open reduction in 1 elbow for a Mason type 4 fracture of the radial head that was internally fixed using fine threaded implants, an elbow fixator with motion capacity was applied in all 4 elbows for a period of 6 weeks. One year after surgery, the active range of motion was 0/10/140 degrees of extension and flexion on the right and 0/0/130 degrees on the left side. The second patient achieved 0/0/125 degrees and 0/10/130, respectively. Pro- and supination was full in both patients. All 4 elbows were stable and there were no radiologic signs of degenerative changes at the 1 year follow-up. Treatment of bilateral elbow dislocation using external fixation with early motion capacity allows for active physiotherapy although maintaining joint stability, thus minimizing complications normally associated with the injury. Using this method resulted in an excellent clinical outcome for both patients.