Multicenter Evaluation of Circulating Cell-Free DNA Extraction and Downstream Analyses for the Development of Standardized (Pre)analytical Work Flows.

BACKGROUND: In cancer patients, circulating cell-free DNA (ccfDNA) can contain tumor-derived DNA (ctDNA), which enables noninvasive diagnosis, real-time monitoring, and treatment susceptibility testing. However, ctDNA fractions are highly variable, which challenges downstream applications. Therefore, established preanalytical work flows in combination with cost-efficient and reproducible reference materials for ccfDNA analyses are crucial for analytical validity and subsequently for clinical decision-making. METHODS: We describe the efforts of the Innovative Medicines Initiative consortium CANCER-ID (http://www.cancer-id.eu) for comparing different technologies for ccfDNA purification, quantification, and characterization in a multicenter setting. To this end, in-house generated mononucleosomal DNA (mnDNA) from lung cancer cell lines carrying known TP53 mutations was spiked in pools of plasma from healthy donors generated from 2 different blood collection tubes (BCTs). ccfDNA extraction was performed at 15 partner sites according to their respective routine practice. Downstream analysis of ccfDNA with respect to recovery, integrity, and mutation analysis was performed centralized at 4 different sites. RESULTS: We demonstrate suitability of mnDNA as a surrogate for ccfDNA as a process quality control from nucleic acid extraction to mutation detection. Although automated extraction protocols and quantitative PCR-based quantification methods yielded the most consistent and precise results, some kits preferentially recovered spiked mnDNA over endogenous ccfDNA. Mutated TP53 fragments derived from mnDNA were consistently detected using both next-generation sequencing-based deep sequencing and droplet digital PCR independently of BCT. CONCLUSIONS: This comprehensive multicenter comparison of ccfDNA preanalytical and analytical work flows is an important contribution to establishing evidence-based guidelines for clinically feasible (pre)analytical work flows.

Outcomes of proximal humeral fracture fixation with locked CFR-PEEK plating.

PURPOSE: To investigate the outcomes of proximal humeral fracture (PHF) fixation with a novel carbon-fiber-reinforced (CFR)-PEEK plate and to compare results with outcomes after conventional locked titanium plating. METHODS: Twenty-one patients (7 male, 14 female) with operative treatment of unilateral displaced PHFs (mean age, 66.8 ± 9.9 years) with a novel CRF-PEEK plate were prospectively enrolled. Patients were followed up clinically (Constant Score, Simple Shoulder Test and Simple Shoulder Value) and radiologically 3 months postoperative and again clinically 12 months postoperative. Implant-related complications were evaluated after 3 and 12 months. Results at 1-year follow-up were compared with results of 21 patients (7 male, 14 female; mean age, 67.4 ± 9.7 years) with conventional titanium locked plating by matched case-control analysis. RESULTS: All functional outcomes improved after CFR-PEEK plating (p < 0.05). Twelve months postoperatively, the mean age- and gender-related Constant Score was 99.8 ± 21.2%. All fractures healed by the 3-month follow-up without evidence of secondary screw perforation, fragment displacement or loss of fixation. There were no significant differences between the functional outcomes of patients with the CF-PEEK plate and patients with locked titanium plating (p > 0.05). Patients with locked titanium plating were significantly more likely to require revision surgery related to articular screw perforations (p = 0.048). CONCLUSIONS: Fracture fixation of displaced PHFs with a novel CFR-PEEK plate resulted in good to excellent 1-year functional outcomes which were similar to outcomes of conventional locked titanium plating. The stiffer locked titanium plating was associated with a higher risk of articular screw perforations than the more elastic CFR-PEEK plate.

Long-acting recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in children. Results of a phase 3 trial.

A global phase 3 study evaluated the pharmacokinetics, efficacy and safety of a recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in 27 previously treated male children (1-11 years) with severe and moderately severe haemophilia B (factor IX [FIX] activity ≤2 IU/dl). All patients received routine prophylaxis once every seven days for up to 77 weeks, and treated any bleeding episodes on-demand. The mean terminal half-life of rIX-FP was 91.4 hours (h), 4.3-fold longer than previous FIX treatment and clearance was 1.11 ml/h/kg, 6.4-fold slower than previous FIX treatment. The median (Q1, Q3) annualised spontaneous bleeding rate was 0.00 (0.00, 0.91) and was similar between the <6 years and ≥6 years age groups, with a weekly median prophylactic dose of 46 IU/kg. In addition, patients maintained a median trough level of 13.4 IU/dl FIX activity on weekly prophylaxis. Overall, 97.2 % of bleeding episodes were successfully treated with one or two injections of rIX-FP (95 % CI: 92 % to 99 %), 88.7 % with one injection, and 96 % of the treatments were rated effective (excellent or good) by the Investigator. No patient developed FIX inhibitors and no safety concerns were identified. These results indicate that rIX-FP is safe and effective for preventing and treating bleeding episodes in children with haemophilia B with weekly prophylaxis. Routine prophylaxis with rIX-FP at treatment intervals of up to 14 days are currently being investigated in children with severe and moderately severe haemophilia B. Clinicaltrials.gov (NCT01662531).

Influence of plate material and screw design on stiffness and ultimate load of locked plating in osteoporotic proximal humeral fractures.

INTRODUCTION: The main purpose was to compare the biomechanical properties of a carbon-fibre reinforced polyetheretherketone (CF-PEEK) composite locking plate with pre-existing data of a titanium-alloy plate when used for fixation of an unstable 2-part fracture of the surgical neck of the humerus. The secondary purpose was to compare the mechanical behaviour of locking bolts and conventional locking cancellous screws. METHODS: 7 pairs of fresh frozen human humeri were allocated to two equal groups. All specimens were fixed with the CF-PEEK plate. Cancellous screws (PEEK/screw) were compared to locking bolts (PEEK/bolt) for humeral head fixation. Stiffness, fracture gap deflection and ultimate load as well as load before screw perforation of the articular surface were assessed. Results were compared between groups and with pre-existing biomechanical data of a titanium-alloy plate. RESULTS: The CF-PEEK plate featured significantly lower stiffness compared to the titanium-alloy plate (P<0.001). In ultimate load testing, 6 out of 14 CF-PEEK plates failed due to irreversible deformation and cracking. No significant difference was observed between results of groups PEEK/screw and PEEK/bolt (P>0.05). DISCUSSION: The CF-PEEK plate has more elastic properties and significantly increases movement at the fracture site of an unstable proximal humeral fracture model compared to the commonly used titanium-alloy plate. The screw design however does neither affect the constructs primary mechanical behaviour in the constellation tested nor the load before screw perforation.

Long-acting recombinant coagulation factor IX albumin fusion protein (rIX-FP) in hemophilia B: results of a phase 3 trial.

A global phase 3 study evaluated the pharmacokinetics, efficacy, and safety of recombinant fusion protein linking coagulation factor IX with albumin (rIX-FP) in 63 previously treated male patients (12-61 years) with severe hemophilia B (factor IX [FIX] activity ≤2%). The study included 2 groups: group 1 patients received routine prophylaxis once every 7 days for 26 weeks, followed by either 7-, 10-, or 14-day prophylaxis regimen for a mean of 50, 38, or 51 weeks, respectively; group 2 patients received on-demand treatment of bleeding episodes for 26 weeks and then switched to a 7-day prophylaxis regimen for a mean of 45 weeks. The mean terminal half-life of rIX-FP was 102 hours, 4.3-fold longer than previous FIX treatment. Patients maintained a mean trough of 20 and 12 IU/dL FIX activity on prophylaxis with rIX-FP 40 IU/kg weekly and 75 IU/kg every 2 weeks, respectively. There was 100% reduction in median annualized spontaneous bleeding rate (AsBR) and 100% resolution of target joints when subjects switched from on-demand to prophylaxis treatment with rIX-FP (P< .0001). The median AsBR was 0.00 for all prophylaxis regimens. Overall, 98.6% of bleeding episodes were treated successfully, including 93.6% that were treated with a single injection. No patient developed an inhibitor, and no safety concerns were identified. These results indicate rIX-FP is safe and effective for preventing and treating bleeding episodes in patients with hemophilia B at dosing regimens of 40 IU/kg weekly and 75 IU/kg every 2 weeks. This trial was registered at www.clinicaltrials.gov as #NCT0101496274.

Recovery of subscapularis and shoulder function following arthroscopic treatment of isolated anterior and combined anterosuperior rotator cuff lesions.

BACKGROUND: The purpose of the study was to evaluate the recovery of the subscapularis and shoulder function dependent on the type of lesion and type of surgical treatment, when compared to the non-affected contralateral shoulder. We hypothesized that regardless of type of lesion and performed surgical intervention, a significant muscle insufficiency as compared to the healthy contralateral side will remain. PATIENTS AND METHODS: Sixty-eight patients (14 females and 54 males) with an anterior or anterosuperior cuff lesion at an average age of 55.7 ± 11.7 years (range 20-80 years) were prospectively evaluated up to 24 months. Intraoperatively, the lesions were classified according to current systems and treated by debridement or reconstruction. Pre- and postoperatively, the Constant Score (CS) as well as the belly-press angle (BPA) and back-to-hand distance (BHD) on the affected and on the contralateral shoulder was noted. RESULTS: 29.4% had an isolated subscapularis lesion whereas 69.1% had concomitant supraspinatus pathology. In 17 patients an arthroscopic debridement and in 51 patients an arthroscopic repair were performed. Postoperatively, all patients revealed a significant improvement of the CS, BPA and BHD (p < 0.05) independent of the type of lesion or the surgical intervention. However, reconstruction of the subscapularis tendon resulted in significant differences of CS, BPA and BHD (p < 0.05) compared to the contralateral shoulder. CONCLUSION: Reconstruction of subscapularis lesions cannot provide full subscapularis function since a residual subscapularis insufficiency remains, other than in patients with small partial tears treated with debridement alone.

Arthroplasty compared to internal fixation by locking plate osteosynthesis in comminuted fractures of the distal humerus.

PURPOSE: The purpose of this study was to evaluate and compare the results after double locking plate osteosynthesis (ORIF) and total elbow arthroplasty (TEA) in AO type C fractures of the distal humerus. METHODS: This retrospective study includes clinical results of 29 patients (9xTEA, 20xORIF) with a mean age of 62 years. The male to female ratio was 8:21. Range of motion, MEPS, DASH and complications were evaluated. Patients older than 60 years (n = 19) were filtered and compared statistically. RESULTS: After a mean follow-up of 25 months the ORIF-group reached an extension-flexion of 99°±23° and the TEA-group of 111°±13°. The ORIF-group vs. the TEA-group had a mean MEPS of 85±17 vs. 94±11 and DASH of 34±24 vs. 24±12. In patients older than 60 years extension-flexion was 97°±23° after ORIF and 110°±14 after TEA (p = 0.237). The ORIF-group vs. the TEA-group had a mean MEPS of 82±21 vs. 94±11 (p = 0.078) and DASH of 45±18 vs. 26±11 (p = 0.023). The ORIF-group had a 4.4 times higher risk for major complications. CONCLUSION: TEA and ORIF lead to comparable functional results, but major complications are more common after ORIF. Despite this, ORIF remains the gold standard for younger and older patients because of the lifelong loading limitation after TEA, unknown implant survival and problematic revision surgery. For patients older than 60 years a primary TEA can be recommended in exceptional cases, if the loading limitation is acceptable for the individual or the fracture is not reconstructable.

Coenzyme A-transferase-independent butyrate re-assimilation in Clostridium acetobutylicum-evidence from a mathematical model.

The hetero-dimeric CoA-transferase CtfA/B is believed to be crucial for the metabolic transition from acidogenesis to solventogenesis in Clostridium acetobutylicum as part of the industrial-relevant acetone-butanol-ethanol (ABE) fermentation. Here, the enzyme is assumed to mediate re-assimilation of acetate and butyrate during a pH-induced metabolic shift and to faciliate the first step of acetone formation from acetoacetyl-CoA. However, recent investigations using phosphate-limited continuous cultures have questioned this common dogma. To address the emerging experimental discrepancies, we investigated the mutant strain Cac-ctfA398s::CT using chemostat cultures. As a consequence of this mutation, the cells are unable to express functional ctfA and are thus lacking CoA-transferase activity. A mathematical model of the pH-induced metabolic shift, which was recently developed for the wild type, is used to analyse the observed behaviour of the mutant strain with a focus on re-assimilation activities for the two produced acids. Our theoretical analysis reveals that the ctfA mutant still re-assimilates butyrate, but not acetate. Based upon this finding, we conclude that C. acetobutylicum possesses a CoA-tranferase-independent butyrate uptake mechanism that is activated by decreasing pH levels. Furthermore, we observe that butanol formation is not inhibited under our experimental conditions, as suggested by previous batch culture experiments. In concordance with recent batch experiments, acetone formation is abolished in chemostat cultures using the ctfa mutant.

Biomechanical effects of calcar screws and bone block augmentation on medial support in locked plating of proximal humeral fractures.

BACKGROUND: The objective of this study was to investigate the biomechanical effects of medial fracture gap augmentation in locked plating of an unstable 2-part proximal humeral fracture with calcar screws and insertion of a corticocancellous bone block. Furthermore the mechanical behavior of dynamic locking screws in the non-parallel arrangement of a proximal humeral plate was of interest. METHODS: Thirty-two fresh frozen humeri were randomized in four equal groups. An unstable 2-part fracture was fixed by locked plating in all specimens. The basic screw setup was supplemented by additional calcar screws in one group. Humeral head screws were replaced by dynamic locking screws in a second group. The third group featured an additional corticocancellous femoral head allograft. Assessment of stiffness was followed by cyclic loading and load to failure tests. Resulting stiffness, fracture gap deflection and ultimate load were compared utilizing Bonferroni corrected t-test for independent samples. FINDINGS: The mechanical effect of additional calcar screws was non-significant as compared to the basic screw configuration whereas bone block insertion significantly increased construct stiffness and failure load. The use of dynamic locking screws did not significantly reduce construct stiffness when compared to conventional locking screws. INTERPRETATION: Additional calcar screws alone did not improve the initial biomechanical properties of an unstable 2-part proximal humeral fracture model. However bone block augmentation appeared to be a reliable alternative of additional bony support by raising stiffness and failure load. Dynamic locking screws did not show their expected dynamic component when used in a non-parallel arrangement.

Arthroscopy after locked plating of proximal humeral fractures: implant removal, capsular release, and intra-articular findings.

PURPOSE: The purpose of this study was to determine the outcomes of arthroscopy after proximal humeral plating and the occurrence of concomitant pathology and avascular necrosis. METHODS: Forty-five patients (28 women; median age, 58.5 years [range, 30 to 82 years]) underwent arthroscopies of 46 shoulders because of unsatisfactory results after locked plating of proximal humeral fractures. They were prospectively followed up for 3, 12, and 24 months postoperatively. Relevant intra-articular lesions were documented. The patients were assigned to 1 of the following groups: (1) articular screw perforation, (2) subacromial plate impingement, or (3) post-traumatic/postoperative shoulder stiffness. Shoulder range of motion and function as measured with the age- and gender-adjusted Constant-Murley score, as well as the Simple Shoulder Test, were compared among the groups. RESULTS: Concomitant lesions of the articular cartilage, long head of the biceps tendon, tuberosities, and rotator cuff were found in 34 patients (75%). Two-thirds of patients (n = 31) had a partial or complete 270° capsular release. Of the patients, 84% (n = 38) underwent 3 and 12 months' follow-up and 82% (n = 37) underwent 24 months' follow-up. The active range of abduction (P = .029), flexion (P = .048), and internal rotation (P = .0005) had improved significantly at 24 months' follow-up compared with the preoperative status. The mean adjusted Constant-Murley score of patients with post-traumatic shoulder stiffness (n = 15, 64.2% ± 7.9%) and articular screw perforation (n = 19, 73.3% ± 8.4%) was significantly lower (P = .0089 and P = .042, respectively) than that of patients with subacromial plate impingement (n = 12, 93.4% ± 4.3%). CONCLUSIONS: High rates of relevant articular pathologies and the necessity of capsular release in a majority of patients with unsatisfactory results after locked plating of proximal humeral fractures make arthroscopy a valuable revision tool with promising results in cases of high plate positioning, screw perforation, and postoperative/post-traumatic shoulder stiffness. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

The Influence of Local Bone Density on the Outcome of One Hundred and Fifty Proximal Humeral Fractures Treated with a Locking Plate.

BACKGROUND: There is biomechanical evidence that bone density predicts the mechanical failure of implants. The aim of this prospective study was to evaluate the influence of local bone mineral density on the rate of mechanical failure after locking plate fixation of proximal humeral fractures. METHODS: We enrolled 150 patients who were from fifty to ninety years old with a closed, displaced proximal humeral fracture fixed with use of a locking plate from July 2007 to April 2010. There were 118 women and thirty-two men who had a mean age of sixty-nine years. Preoperative computed tomography (CT) scans were done to assess bone mineral density of the contralateral humerus, and dual x-ray absorptiometry of the distal end of the radius of the unaffected arm was conducted within the first six weeks postoperatively. At follow-up evaluations at six weeks, three months, and one year postoperatively, pain, shoulder mobility, strength, and multiple functional and quality-of-life outcome measures (Disabilities of the Arm, Shoulder and Hand [DASH] questionnaire; Shoulder Pain and Disability Index [SPADI]; Constant score; and EuroQuol-5D [EQ-5D]) were done and standard radiographs were made. We defined mechanical failure as all complications related to bone quality experienced within one year. RESULTS: After locking plate fixation, fifty-three (35%) of 150 patients had mechanical failure; loss of reduction and secondary screw loosening with perforation were common. CT assessments of local bone mineral density showed no difference between patients with and without mechanical failure (89.82 versus 91.51 mg/cm3, respectively; p = 0.670). One-year DASH, SPADI, and Constant scores were significantly better for patients without mechanical failure (p ≤ 0.05). CONCLUSIONS: We did not find evidence of an association between bone mineral density and the rate of mechanical failures, which may suggest that patients with normal bone mineral density are less prone to sustain a proximal humeral fracture. Future studies should target other discriminating factors between patients with and without mechanical failure. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Identification of PTS(Fru) as the major fructose uptake system of Clostridium acetobutylicum.

As a member of the saccharolytic clostridia, a variety of different carbohydrates like glucose, fructose, or mannose can be used as carbon and energy source by Clostridium acetobutylicum ATCC 824. Thirteen phosphoenolpyruvate-dependent phosphotransferase systems (PTS) have been identified in C. acetobutylicum, which are likely to be responsible for the uptake of hexoses, hexitols, or disaccharides. Here, we focus on three PTS which are expected to be involved in the uptake of fructose, PTS(Fru), PTS(ManI), and PTS(ManII). To analyze their individual functions, each PTS was inactivated via homologous recombination or insertional mutagenesis. Standardized comparative batch fermentations in a synthetic medium with glucose, fructose, or mannose as sole carbon source identified PTS(Fru) as primary uptake system for fructose, whereas growth with fructose was not impaired in PTS(ManI) and slightly altered in PTS(ManII)-deficient strains of C. acetobutylicum. The inactivation of PTS(ManI) resulted in slower growth on mannose whereas the loss of PTS(ManII) revealed no phenotype during growth on mannose. This is the first time that it has been shown that PTS(Fru) and PTS(ManI) of C. acetobutylicum are directly involved in fructose and mannose uptake, respectively. Moreover, comprehensive comparison of the fermentation products revealed that the loss of PTS(Fru) prevents the solvent shift as no butanol and only basic levels of acetone and ethanol could be determined.

Has the arthroscopically assisted reduction of acute AC joint separations with the double tight-rope technique advantages over the clavicular hook plate fixation?

PURPOSE: The purpose of this study was to compare the results after arthroscopically assisted double TightRope(®)-(TR) reduction with results after clavicular hook plate (HP) fixation in acute high-grade acromioclavicular (AC) joint separations. METHODS: Between 2004 and 2010, 69 consecutive patients with acute AC joint separations type Rockwood III and V were subjected to surgical reconstruction. 56 patients (81 %) were available for evaluation. Thereof, 30 (median age: 39 years; n = 12 acute Rockwood III and n = 18 Rockwood V injuries) were treated by a clavicular HP and 26 (median age: 39 years; n = 10 acute Rockwood III and n = 16 Rockwood V injuries) using the double TR technique. Group HP was evaluated at a median of 48 (7-77) months after surgery and the TR group 17 (7-29) months after stabilization. Visual Analogue Scale (VAS) for Pain, Simple Shoulder Test (SST), Constant Score (CS) and Taft Score (TS) were assessed. Sonographic measurements were performed to evaluate recurrent instability. RESULTS: Clinical examination demonstrated comparable results without significant differences. In the groups HP and TR, the VAS was median 0.8 (range, 0.0-7.5) and 0.4 (range, 0.0-5.7), the SST reached median 11 (range, 0-12 points) and 12 points (range, 8-12 points). The CS was median 92.4 % (range, 21.5-105.4 %) and 94.0 % (range, 54.6-105.3 %) and the TS median 10 (range, 3-12 points) and 10 points (range, 5-12 points). Sonographic measurements showed a mean coracoclavicular (CC) distance of 25.3 ± 4.5 (HP) and 25.5 ± 4.3 mm (TR) (n.s.). In both groups, CC distance of the operated side was significantly higher compared to the uninjured side. The complication rate was 13 % in group HP and 12 % in group TR. CONCLUSIONS: In acute high-grade AC joint instabilities, both techniques lead to mostly good and excellent clinical results, although comparable partial recurrent vertical instability could be observed. Diagnosis and therapy of concomitant glenohumeral injuries and no obligatory implant removal are advantages of the arthroscopic procedure.

Treatment of osteochondral fractures of the knee: a meta-analysis of available scientific evidence.

PURPOSE: Although traumatic osteochondral fractures of the knee represent a common pathology of the knee joint, there is no general agreement concerning specific treatment of this entity. This meta-analysis was initiated in order to evaluate scientific evidence on different treatment options for acute osteochondral fractures of the knee. METHODS: For this purpose an OVID-based systematic literature search was performed including the following databases: MEDLINE, MEDLINE preprints, Embase, CINAHL, Life Science Citations, British National Library of Health and Cochrane Central Register of Controlled Trials. The literature search period was from 1946 to January 2012, which led to the identification of 1,226 articles. After applying study-specific inclusion criteria a total of 19 studies with clinical follow-up of 638 patients were included. The methodology of these studies was systematically analysed by means of the Coleman Methodology Score. Outcome and success rates were evaluated depending on treatment applied. RESULTS: All studies (n = 19) identified represent case series (evidence-based medicine level IV) and included a total of 638 patients. The average post-operative follow-up was 46 ± 27 months (range 3.75-108). The mean number of study subjects per study was 33 ± 44 patients (range 4-169). The average Coleman Methodology Score was 29 ± 17 points (range 5-72). Six different scoring systems were used for clinical assessment. The overall clinical success rate was 83% and varied between 45 and 100%. CONCLUSIONS: This meta-analysis reveals a significant lack of scientific evidence for treatment of osteochondral fractures of the knee. No valid conclusion can be drawn from this study concerning the recommendation of a specific treatment algorithm. Nevertheless, the overall failure rate of 17% underlines that an acute osteochondral fracture of the knee represents an important pathology which is not a self-limiting injury and needs further investigation.

Arthroscopically assisted stabilization of chronic AC-joint instabilities in GraftRope™ technique with an additive horizontal tendon augmentation.

PURPOSE: A chronic symptomatic acromioclavicular joint (ACJ) instability is a possible consequence of an acute ACJ separation. Besides vertical instability a horizontal component of the instability is common in high-grade ACJ separation and clinically relevant; especially, in chronic cases. A new technique of horizontal biologic ACJ augmentation with a transacromial gracilis tendon loop as an addition to the arthroscopically assisted stabilization with the GraftRope™ device is described and first clinical and sonographical results are shown. HYPOTHESIS: The results after arthroscopically assisted single bundle reconstruction of the coracoclavicular (CC) ligaments with an additional horizontal tendon augmentation are comparable to the results of other stabilizing techniques in chronic ACJ instabilities. METHODS: A consecutive series of 20 patients with chronic symptomatic ACJ instability was stabilized with this new technique. 16 patients were followed-up clinically and sonographically. Patient satisfaction, visual analogue scale (VAS), simple shoulder test (SST), Constant score (CS) and Taft score (TS) were assessed. Bilateral sonographic measurements were performed to evaluate recurrent instabilities. Complications and concomitant glenohumeral injuries were analyzed. RESULTS: Sixteen patients (n = 2 female, n = 14 male, median age 40 (21-61) years, follow-up rate 84 %) were evaluated median 13 months (range 4-27 months) after indexed operation. 11 patients had a chronic ACJ instability after Rockwood type III, and 5 patients after Rockwood type V lesion. 6 patients suffered a recurrent symptomatic instability after operative treatment. 10 patients of the group were primary stabilized with the new technique. 15 of 16 patients were satisfied with the result of the operation at the follow-up examination. The VAS was median 4.6 of 10 points (range 1.1-7.4 points). The SST reached 9 points (range 5-12 points). The adjusted CS was median 84 % (range 46-93 %) and TS median 9 points (range 5-12 points). The sonographic measurements showed a significant difference in the CC distance between the unaffected and the affected side (21.7 vs. 24.8 mm, p = 0.009). The acromioclavicular distance was median 11 mm (range 7-17 mm) after resection of the lateral clavicle. Concomitant glenohumeral injuries were arthroscopically detected in seven patients. Postoperative complications occurred in one patient (wound infection). In one case, the clavicular washer was removed due to local paresthesia after healing of the graft. CONCLUSIONS: The arthroscopically assisted stabilization of chronic ACJ instabilities with the GraftRope™ device and an additive horizontal tendon augmentation technique leads to good short-term results with a supplementary horizontal stabilization.

Biomechanical testing of a new plate system for the distal humerus compared to two well-established implants.

PURPOSE: A biomechanical study was performed to test the hypothesis that a new anatomically preformed, thinner, soft-tissue protecting plate system for distal humeral fractures (Tifix®-hybridplate [HP]) would show comparable results in the quasi-static and dynamic testings compared to two conventional implants: The 3.5-mm reconstruction plate (RP) providing primary stability with normal bone mineral density (BMD), and a multidirectional locking plate (Tifix(®)-plate [P]) which can be used with poor bone quality. METHODS: The Tifix(®)-HP was developed by the working group. The biomechanical testing was performed on a C2-fracture-model in 24 synthetic humeri. Three groups, each with eight bone-implant-constructs, were analysed in quasi-static and dynamic tests. RESULTS: The quasi-static measurements showed that under extension loading both locking plates (Tifix(®)-P, Tifix(®)-HP) were significantly stiffer than the reconstruction plate, and that the Tifix(®)-HP had a significantly lower stiffness than the two other implants under flexion loading. In the dynamic tests the Tifix(®)-P allowed significantly less fracture motion compared to the Tifix(®)-HP and the reconstruction plate. In an osteopaenic bone model locking plates failed only under much higher dynamic force than the reconstruction plate. The reconstruction plate and the Tifix(®)-P always failed through screw loosening, whereas the newly developed Tifix(®)-HP showed screw loosening in only one third of cases. CONCLUSION: The hypothesis that the newly designed plate system showed comparable results in the quasi-static and dynamic tests compared to the conventional implants with a significantly lower implant volume and thickness was confirmed.

Anterior cruciate ligament reconstruction using bone plug-free quadriceps tendon autograft: intermediate-term clinical outcome after 24-36 months.

INTRODUCTION: Although known as a possible graft option for decades, quadriceps tendon grafts have often been termed a second-line graft option. We report a consecutive case series using this method as the primary treatment line. The rationale for this study was to evaluate the midterm results of this method in a prospective and consecutive case series. The primary study question was to determine the clinical results 24-36 months after primary anterior cruciate ligament (ACL) reconstruction using a bone plug-free quadriceps tendon autograft fixed with bioabsorbable cross-pins. MATERIALS AND METHODS: The study population included 55 patients, of whom 24 were female (43.6%). The mean age at the index procedure was 31.7 years (15-58 years). All patients received an ACL construction using a bone block-free quadriceps tendon graft fixed with resorbable cross-pins. The postoperative regimen included partial weight-bearing for 3 weeks and flexion limited to 90° for six weeks; an orthosis was not used. The mean follow-up duration was 29.5 months (24.3-38.5 months) after the index procedure. The International Knee Documentation Committee (IKDC) subjective score and examination form was assessed, as well as the Lysholm and Gillquist score and the Tegner activity index. The Rolimeter arthrometer was used to assess the anterior laxity of the knee. RESULTS: Graft harvesting was possible in all cases; a bony extension was never required. On average, graft length was measured at 8.8 cm (7.5-10 cm). The mean IKDC subjective score at follow-up was 80.44 points (55.17-100 points, standard deviation [SD] 12.05). The mean preinjury Tegner activity index was 4.98 (2-7) compared to a mean value of 4.16 (2-7, SD 0.8) at follow-up. There was a mean loss of 0.82 index points. The average Lysholm and Gillquist score was 89 points (65-100, SD 17.7). Of the results, 89.1% were in the good or very good groups; in one case (1.8%), the result was poor, while the rest were fair. CONCLUSION: ACL reconstruction using a bone plug-free quadriceps tendon autograft achieved satisfactory results in a midterm review.

Monobloc radial head prostheses in complex elbow injuries: results after primary and secondary implantation.

PURPOSE: Dislocations of components, loosening of the stem, overstuffing and removal in up to 24 % of common radial head prostheses (RHP) after implantation in complex elbow injuries signal the need for improvement. The latest biomechanical evidence shows advantages for monopolar designs. Clinical results after primary and secondary implantation of the newly designed press-fit monobloc monopolar RHP in cases of complex elbow injury are evaluated. METHODS: Twenty-nine patients [median age 60 years (29-86)] were followed up retrospectively for a median of 25 months (7-54) post-operatively. Subjective parameters, the Mayo Elbow Performance Score (MEPS), the Broberg and Morrey score (BMS), latest radiographs and complications were evaluated. RESULTS: MEPS and BMS averaged 87.2 ± 12.9 and 81.1 ± 11.9 points, respectively. No case of implant loosening was observed; the RHP had to be removed in one case (3 %). The overall complication and revision rate was higher after secondary (53 %) than after primary (19 %) implantation. CONCLUSIONS: Satisfactory clinical results and low short-term removal rates emphasise the practicality of monobloc monopolar RHP. Differentiated treatment of complex elbow fracture-dislocations is compulsory to avoid the need for secondary RHP implantation which carries a higher complication rate.