Surgical Drill Guide for Insertion of an Infra-Acetabular Screw Based on an Anatomically Precontoured Plate System: A Cadaveric Study.

PURPOSE: Due to the anatomic structure of the pelvis, free-hand placement of screws in the acetabular fracture management can be difficult. Infra-acetabular screw fixation increases acetabular stability by distal fixation of the cup. Aim of this cadaveric study is to investigate if a plate-referenced drill guide can provide save placement of an infra-acetabular screw over a precontoured suprapectineal quadrilateral buttress plate (SQBP). METHODS: We constructed a drill guide for an infra-acetabular screw based on the surface of an anatomically precontoured SQBP. A total of 12 adult cadaveric acetabular specimens were used for drill guide-assisted placement of the infra-acetabular screw. The drill guide contains a radiopaque spiral to allow longitudinal fine adjustment of the SQBP along the pelvic brim to assure correct position of the plate-drill-guide construct in relation to the Koehler's teardrop. After screw placement, we conducted a computed tomography (CT) scan of all specimens to assess the actual position of the screw in relation of the infra-acetabular corridor and the acetabular joint surface. RESULTS: The position of the screw was within the infra-acetabular corridor in all cases. We did not see any intra-articular or intrapelvic screw penetration. The mean distance of the centerline of the screw to the medial border of the infra-acetabular corridor was 3.35 mm. The secure distance to the virtual surface of the femoral head to was 7.3 mm. CONCLUSIONS: A plate-referenced drill guide can provide safe placement of an infra-acetabular screw for treatment of acetabular fractures. Radiographic fine adjustment is necessary to access the optimal entry point.

Injury Analysis in Professional Soccer by Means of Media Reports - Only Severe Injury Types Show High Validity.

PURPOSE: Injury data of professional soccer players obtained from media reports are frequently used in scientific research, but the accuracy of such data is still unclear. PATIENTS AND METHODS: Injuries of professional soccer players of the German first and second league were documented by continuously screening media reports over one season (2015-2016). After the season, the validity of media-reported injuries was anonymously analyzed by the team physicians of 8 different soccer clubs. RESULTS: A total of 255 injuries of 240 players of 8 professional soccer teams had been published online, of which 146 were confirmed by the team doctors as correct, yielding a rate of 57.3% of confirmed media-reported injuries. In addition, 92 injuries without media registration were detected and added to the online statistics, resulting in 347 injuries and an overall weak validity of media-based data of 42.1%. Statistical analysis showed that the validity of media-reported injury data depended on both the individual soccer club and the body site affected by injury: publications on knee injuries (78.2%) had a higher validity than those on foot injuries (46.2%), and publications on severe injuries had a higher validity (joint dislocation: 100%; ligament rupture: 82.9%; fracture: 73.3%) than those on minor injuries. Publications on specific severe soccer injuries, such as anterior cruciate ligament (ACL) injuries, had a validity of 100%. CONCLUSION: Media-based injury data were only valid for a few severe injury types such as ACL injuries. In daily soccer routine and scientific research, media-based data should thus only be used in combination with specific criteria or verification processes.

Novel implant-free loop Tenodesis vs. simple Tenotomy of the long biceps tendon - a biomechanical investigation.

BACKGROUND: Simple tenotomy and anchor tenodesis are commonly used in treatment of long biceps tendon (LHB) pathologies. The tenotomy can result in biceps distalization or cosmetic deformities. A novel loop Tenodesis Technique (LTD) could prevent a distalization of the biceps muscle without the risk of implant associated complications. The purpose of this study was to investigate the biomechanical aspects of the novel LTD compared to a standard tenotomy of the LHB. It has been hypothesized that the novel technique will show biomechanical superiority in terms of resistance and distalization. METHODS: Seven paired adult human cadaveric shoulder joints were assigned to one of the two study groups: Loop tenodesis (LTD); simple tenotomy (STT). In both groups load-to-failure testing was performed. The load-displacement curve was used to determine the maximum load (N), the degree of distalization of the LHB (mm) and the stiffness (N/mm). Additionally, the mode of failure was registered. RESULTS: The LTD group achieved a significantly higher ultimate load to failure (LTD: 50.5 ± 12.5 N vs. STT: 6.6 ± 3.9 N; p = 0.001). Significantly less distalization of the tendon could be detected for the LTD group (LTD: 8 ± 2.3 mm vs. STT: 22.4 ± 2.4 mm; p = 0.001). Stiffness was 7.4 ± 3.9 N/mm for the LTD group and 0.23 ± 0.16 N/mm for the STT group (p = 0.001). In all specimens of the LTD group a tendon rupture was found as mode of failure, while the STT group failed because of pulling out the LHB through the bicipital groove. CONCLUSION: The novel loop Tenodesis Technique shows biomechanically higher stability as well as less distalization compared to a simple tenotomy of the long biceps tendon.

Normal values of distal radioulnar translation assessed by three-dimensional C-arm scans: a cadaveric study.

We investigated whether mobile C-arm cone beam computer tomography (CBCT) could be used to measure radioulnar translation. The study was conducted on 31 Thiel-fixed intact cadaver arms. Three-dimensional scans of each wrist were carried out in pronation and supination. Four established measurement methods were used (radioulnar line, subluxation ratio, epicentre and radioulnar ratio methods) to measure radioulnar translation. The intraclass correlation coefficient for inter-observer and intra-observer reliability were excellent in three of four methods (>0.94). The reference ranges for physiological radioulnar translation were between -30% and 91% (radioulnar line method), -32% and 87% (subluxation ratio method), -40% and 23% (epicentre method), and 2% and 73% (radioulnar ratio method). Our results indicate that radioulnar translation in the distal radioulnar joint can be determined reliably using mobile C-arm CBCT. The normal values provide a basis for further experimental and clinical studies.

Total Hip Arthroplasty for Hip Fractures: Time to Surgery With Respect to Surgical Revision, Failure, and Mortality.

INTRODUCTION: There are increasing demands to perform surgery of hip fractures without delay. However, few studies have assessed the time to surgery in relation to outcome measurements. METHODS: A total of 643 consecutive patients with a minimum age of 60 years underwent total hip arthroplasty (THA) for an intracapsular hip fracture. For this retrospective case series, demographic data and the outcome measurements-(1) any surgical revision, (2) implant failure, and (3) mortality-were documented from a prospective clinical database. The time from admission to surgery was also documented prospectively and then data were divided into 4 groups according to the time of surgery: (1) within 12 hours, (2) >12 to 24 hours, (3) >24 to 48 hours, and (4) later than >48 hours. The study end point was 2 years after surgery. Final evaluation was conducted for any missing data through a telephone interview. RESULTS: The patients comprised 456 women (70.9%) and 187 men (29.1%) with a mean age of 80.2 years (range 60-104 years; standard deviation ±7.4). Descriptive data were without effect in all 4 groups. Time to surgery did not significantly influence revision for any reason (P = .323), implant failure (P = .521), and mortality (P = .643). Cox regression analysis identified male sex (P < .001; 95% confidence interval (CI), 1.27-2.44), American Society of Anesthesiologists score ≥3 (P < .001; 95% CI, 2.12-21.59), C-reactive protein level >21 mg/L (P < .018; 95% CI, 1.09-2.60), hemoglobin level <12.0 g/dL (P = .033; 95% CI, 1.04-2.68), and dementia (P < .000; 95% CI, 1.50-2.86) as independent significant risk factors for mortality. CONCLUSION: Time to surgery had no effect on revision for any reason, implant failure, and mortality in patients undergoing THA for an intracapsular hip fracture.

Clinical application of a minimally invasive cement-augmentable Schanz screw rod system to treat pelvic ring fractures.

PURPOSE: The purpose of this study is to analyze the results using the USS fracture MIS system (DePuy Synthes) to treat instable pelvic ring fractures. As its outstanding feature, it is the only Schanz screw and rod system at present that combines angular stability, perforation/fenestration of the screws for cement-augmentation, a variable screw length, and a large screw diameter. MATERIALS AND METHODS: Retrospective investigation of 134 pelvic ring fractures treated in 2012-2013. Twenty-five patients obtained the abovementioned implant. Besides baseline characteristics of the included patients and the surgical procedure, a clinical/radiological follow-up of six months was analyzed. RESULTS: Dividing the collective into two groups, I high-energy trauma and II fragility fracture of the pelvis, the following results were recorded: group I: ten patients, six male, age 48.4 ± 19.7 years. Mean ISS 41 ± 22.5, fracture classification: AO/OTA type 61 B1/C1/C3 = 1/5/4. Operative treatment: three transiliac internal fixator, seven iliolumbar fixation, one implant was cement-augmented. Group II: 15 patients, 14 female, age 77.5 ± 10.1 years. Fracture classification according to Rommens: FFPII/III/IV = 6/1/8. Operative treatment: eight transiliac internal fixator, seven iliolumbar fixation, 14 implants were cement-augmented. Overall surgical side complications: 16%. Radiological examination: correct positioning of all ilium screws. Follow-up after six month (16 patients): all showed fracture consolidation. One ilium screw was broken close to the connecting clamp. CONCLUSION: The investigated Schanz screw rod system is a suitable implant to broaden the established procedures to stabilize dorsal pelvic ring fractures. TRIAL REGISTRATION: The study is registered at the Clinical Trial Registry University of Regensburg (Number Z-2017-0878-3).

Determination of Elbow Laxity in a Sequential Soft-Tissue Injury Model: A Cadaveric Study.

BACKGROUND: The objective of our study was to analyze, under fluoroscopy, joint angulation of uninjured elbows and elbows with distinct induced collateral ligament injury. METHODS: Twelve elbow specimens were tested for varus and valgus joint angulation using 4 different examination methods (application of both varus and valgus stress by each of 2 examiners [Examiner 1 and Examiner 2] and application of 1 and 2 Nm of torque using a calibrated electric force scale) in 4 elbow positions (in full extension with 90° of supination and 90° of pronation, and in 30° of flexion with 90° of supination and 90° of pronation). Six elbow specimens were examined under varus stress at each of 5 sequential stages: (1) intact, (2) transection of the lateral ulnar collateral ligament (LUCL), (3) complete transection of the lateral collateral ligament complex (LCLC), (4) transection of the anterior aspect of the capsule (AC), and (5) transection of the medial collateral ligament (MCL). An additional 6 elbow specimens were examined under valgus stress at 5 sequential stages: (1) intact, (2) transection of the anteromedial collateral ligament (AML), (3) complete transection of the MCL, (4) transection of the AC, and (5) transection of the LCLC. Examinations under fluoroscopy were made to measure the joint angulation. Intraclass correlation coefficients (ICCs) were calculated. RESULTS: Testing of the intact elbow specimen by both examiners showed a joint angulation of <5°. Transection of the LUCL led to a varus joint angulation of 4.3° to 7.0°, and transection of the AML resulted in a valgus joint angulation of 4.9° to 8.8°. Complete dissection of the respective collateral ligament complex resulted in a joint angulation of 7.9° to 13.4° (LCLC) and 9.1° to 12.3° (MCL), and additional transection of the AC led to a joint angulation of >20° in some positions in both the medial and the lateral series. Under varus stress, elbow dislocations occurred only after dissection of the LCLC+AC (26% of the examinations) and additional dissection of the MCL (59%). Under valgus stress, elbow dislocations occurred only after dissection of the MCL+AC (30%) and additional dissection of the LCLC (47%). Very good to excellent ICCs were found among Examiners 1 and 2 and the tests done with the standardized torques at stages 1 through 4. CONCLUSIONS: Dynamic fluoroscopy makes it possible to distinguish among different stages of collateral ligament injury of the elbow and therefore might be helpful for guiding treatment of simple elbow dislocations. CLINICAL RELEVANCE: Assessment of collateral ligament injury with varus and valgus stress testing under fluoroscopy is an easily available method and is often used as the imaging modality of choice to determine the degree of elbow laxity. The technique and results described in this study should form the basis for additional clinical studies.

Wire Placement in the Sustentaculum Tali Using a 2D Projection-Based Software Application for Mobile C-Arms: Cadaveric Study.

BACKGROUND: Indirect screw fixation of the sustentaculum tali in the lateral-medial direction can be challenging due to the complex calcaneal anatomy. A novel 2-dimensional (2D) projection-based software application detects Kirschner wires (K-wires) and visualizes their intended direction as a colored trajectory. The aim of this prospectively randomized cadaver study was to investigate whether the software would facilitate the indirect K-wire placement in the sustentaculum tali. METHODS: In 20 cadaver foot specimens, K-wires were placed indirectly in the sustentaculum tali by an experienced and an inexperienced surgeon, with and without using the application. Number of placement attempts, duration of procedure, fluoroscopy time, and number of individual fluoroscopy images were recorded. Each wire's position was analyzed in a 3-dimensional (3D) C-arm scan by an experienced blinded investigator. RESULTS: Use of the software by the inexperienced surgeon significantly reduced the number of placement attempts from 3.2 to 1.2 ( P = .006). The application also reduced operating time, from 273 s to 199 s ( P = .15), and fluoroscopy time, from 41 s to 29 s ( P = .15). Using the software, the experienced surgeon had a longer operating time (139 s to 183 s; P = .30), longer fluoroscopy time (5.6 s to 9.2 s; P = .17), and more individual fluoroscopy images (11.6 to 14.8; P = .30). Wire position did not show significant differences in both cases. CONCLUSION: During indirect K-wire placement in the sustentaculum tali, the software appeared to be a useful tool for the inexperienced surgeon. In our chosen study setting, the experienced surgeon did not benefit from the software. CLINICAL RELEVANCE: Possible indications for the software would be fractures of the proximal femur, sacrum, sacroiliac instabilities, vertebral bodies, scaphoid, Lisfranc joint, talus and calcaneus.

Biomechanical investigation of four different fixation techniques in sacrum Denis type II fracture with low bone mineral density.

With increasing life expectancy, fragility fractures of the pelvic ring are seen more frequently. Although their osteosynthesis can be very challenging, specific biomechanical studies for investigation of the fixation stability are still lacking. The aim of this study was to biomechanically evaluate four different fixation methods for sacrum Denis type II fractures in osteoporotic bone. Unstable Denis type II vertical sacrum fractures were created in 16 human pelves. Their osteosynthesis was performed with one sacro-iliac screw, posterior sacral plating, triangular fixation, or spino-pelvic fixation. For that purpose, each pelvis was randomly assigned to two paired groups for treatment with either SI-screw/posterior sacral plating or triangular fixation/spino-pelvic fixation. Each hemi-pelvis was cyclically tested under progressively increasing axial compression. Relative interfragmentary movements were investigated via optical motion tracking analysis. Axial stiffness of triangular fixation was significantly higher versus posterior sacral plating and spino-pelvic fixation (p ≤ 0.022), but not significantly different in comparison to SI-screw fixation (p = 0.337). Cycles to 2, 3, 5, and 8 mm fracture displacement, as well as to 3°, 5°, and 8° gap angle at the fracture site were significantly higher for triangular fixation compared to all other groups (p ≤ 0.041). Main failure mode for all osteosynthesis techniques was screw cutting through the bone, leading loss of fixation stability. From a biomechanical point of view, triangular fixation in sacrum Denis type II fractures demonstrated less interfragmentary movements and should be considered in unstable fragility fractures of the sacrum. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1624-1629, 2018.

Humeral shaft cerclage wiring: a safe technique to prevent radial nerve injury.

Humeral periprosthetic fractures are a challenging problem and their occurrence has increased, particularly over the last decade. The role of cerclage wires or cables in these fractures includes revisions with longer stems, and augmentation of a plate osteosynthesis in which the stem does not allow additional screw placement or structural bone grafts as supplementary fixation. These procedures are demanding because of the proximity of the radial nerve within the operating field. Placing a cerclage wire or cable around the fractured fragments offers a simple and safe procedure to avoid radial nerve injury or palsy in the treatment of complex humeral shaft fractures. This new technique is a simple and safe procedure to place a cerclage wire or cable around the humeral shaft.

Avoiding radial nerve palsy in proximal radius shaft plating - a cadaver study.

BACKGROUND: Opinions vary concerning the position of forearm rotation during detachment of the supinator in radial nerve palsy Henry's and Thompson's approaches. PURPOSE: To define the optimal forearm position for a safe detachment of the supinator during these approaches and to clarify their close relationship to the posterior interosseous nerve (PIN). METHODS: The study sample comprised 90 upper extremities of 45 human adult cadavers, embalmed using Thiel's method. After detection of the radial nerve in the interval between the brachialis and brachioradialis, its pathway was traced to the Arcade of Frohse (AF). Measurements involved the distance between the AFand the radial border of the distal biceps tendon (DBT) in pronation and supination, the interval between the AF and the radiocapitellar joint space (RCJS) in supination and the radial length (RL). RESULTS: Distances between the DBT and the AF were significantly shorter during pronation (right side: 14.1 ± 3.4mm; left side: 13.5 ± 3.2mm) compared with supination (right side: 20.5 ± 3.6mm; left side: 19.8 ± 3.5mm) for both right and left extremities. The mean interval between the AF and the centre of the RCJS was 25.2 ± 5.9mm for the right side and 24.7 ± 5.6mm for the left side, which correlated positively with the RL. CONCLUSION: These results indicate a safe detachment of the supinator from the radius with the forearm placed in supination during both Henry's and Thompson's approaches.

Comparison of volar and dorsal plate osteosynthesis for radial shaft fractures: an anatomical pilot study.

BACKGROUND: No publication has yet described the interface between the radius and the plate in various positions. Neither clinical examination nor assessment of fracture radiographs provides information about the anatomy of the radius before injury. PURPOSE: We investigated radius anatomy to analyse dorsal and volar plate-to-bone fit for radial shaft fracture management. METHODS: We examined 20 specimens from human adult cadavers. An 8-hole 3.5-mm titanium locking plate was used at three different positions on the dorsal and the volar side of the bone. The space between the well-positioned plate and the radial shaft was attained for each hole of the plate. RESULTS: The average space between the midshaft radial cortex and the plate holes for all positions was 0.69mm (range: 0.0mmto 2.38mm). The greatest mean distance between the plate and the radial cortex was measured at the volar mid-diaphyseal position of the plate with an average of 1.31mm. CONCLUSION: This incongruence between the radial cortex at the volar diaphysis and the plate should be considered when applying plates to this position of the radius. The results of this cadaver study indicate that radius plate osteosynthesis should preferably be done from the dorsal side.

Scaphoid screw placement under minimal radiation exposure.

BACKGROUND: Percutaneous scaphoid fixation through either a volar or dorsal approach has the advantage of minor soft tissue damage compared with ORIF, and faster fracture union compared with conservative treatment. However, this technique demands highly intraoperative reliance on X-ray control, including increased radiation exposure and all associated side effects. PURPOSE: To test the possibility and efficacy of volar percutaneous scaphoid screw placement under minimalradiation exposure. METHODS: The sample included 20 hands (seven left, 13 right) from human adult cadavers. For this study, the utilised wrists were assumed to have non-displaced scaphoid fractures. Using a percutaneous approach, a 2-mm Kirschner wire (K-wire) was advanced to the distal pole of the scaphoid and placed in a 45° horizontal and vertical angle under monitoring with the C-arm. The K-wire was inserted blindly alongside the estimated length of the scaphoid. Following K-wire insertion, four X-rays were taken to depict K-wire positioning and to assess positioning alongside the axis of the scaphoid and K-wire protrusion. The rating scale comprised 1 (good), 2 (moderate) or 3 (poor). RESULTS: All tested radiographic views were evaluated with a median of 2 points (moderate position) regardingplacement alongside the scaphoid axis. CONCLUSION: Our results indicate that percutaneous scaphoid fixation with the guide wire placed in a 45° horizontal and vertical angle enables primary moderate positioning, which may lead to quicker adjustment to the ideal position and a decrease of radiation exposure.

Anatomical and radiological evaluation of less invasive stabilisation system (LISS) in correlation with knee lateral collateral ligament insertion.

INTRODUCTION: The Less Invasive Stabilisation System (LISS) is an angle-stable plate that enables treatment of distal femoral comminuted and periprosthetic fracture. As it is placed through a minimally-invasive lateral approach, lateral knee pain is a commonly described symptom after its application. This study investigates knee lateral collateral ligament (LCL) iatrogenic injury during LISS plate fixation. A cadaver study was performed and a retrospective radiological investigation with the analysis of its clinical application was conducted to evaluate possible knee LCL damage. METHODS: The cadaver study included 13 human lower extremities, treated with LISS. After application, lateral knee side was dissected, implants were removed and distances between the drill holes and LCL origin were measured. In the retrospective radiological evaluation, postoperative X-rays for patients treated with distal femoral LISS plate in the University Hospital Regensburg, Germany from January 2010 to December 2015 were examined. Following a protocol described by Pietrini et al., the LCL origin on postoperative X-rays was calculated, both in lateral and anterior-posterior (AP) view, and distances between the plate and its closest locking screw to the LCL origin were measured. RESULTS: In the cadaver study, the mean distance between the closest drilling hole and the ligament origin was 14.0mm (range 9-21mm; SD 3.8mm). Twenty-two patients matched the inclusion criteria for the retrospective radiological study. In lateral view, the mean distance between the origin and the closest locking screw was 6.3mm (range 0-16.4mm; SD 4.7mm); the mean distance between the origin and the plate was 3.1mm (range 0-13.9mm; SD 4.1mm). In AP view, the mean distance between LCL origin and the nearest screw was 2.4mm (range 0-7.6mm; SD 2.4mm). The mean distance between the origin and the most distal locking screw was 9.2mm (range 0-17.5mm; SD 4.0mm). DISCUSSION: The LISS is a safe option to treat distal femoral fractures in respect to the LCL. Due to close proximity, the LCL might be harmed; therefore, lateral knee pain or lateral instability after implantation should be assessed in further treatment.

Primary stability in total hip replacement: A biomechanical investigation.

BACKGROUND: In total hip replacement (THR), it is essential to achieve a primary stability to guarantee good long-term results. A novel locking screw hip (LSH)-stem, anchored to the medial cortex of the proximal femur by 5 monocortical locking screws, was developed to overcome the shortcomings of uncemented press-fit and cemented straight stems while simultaneously achieving primary stability. The aim of this study was to investigate the biomechanical competence of the LSH-stem in comparison to an uncemented press-fit stem. METHODS: Six pairs of embalmed human cadaveric femora from donors aged 68 to 84 years were assigned to 2 study groups (n = 6) with equal number of right and left bones. The specimens in each group and pair were implanted with either an uncemented press-fit stem or an LSH-stem and tested biomechanically under progressively increasing cyclic axial loading until catastrophic failure. Axial construct stiffness, failure load, and cycles to failure were detected and statistically evaluated at a level of significance P = .05. RESULTS: Although the axial stiffness was comparable for both prosthesis types, the uncemented press-fit stem showed a significant lower stability in terms of failure load and cycles to failure in comparison to the LSH-stem, P = .04. CONCLUSION: Converting our results to percentage of bodyweight (BW) in an assumed adult patient of 80 kg shows that the LSH-stem achieves a primary stability allowing to carry average loads of up to 507% BW, whereas the uncemented press-fit stem carried average loads of up to 404% BW. We conclude that both stems achieve a primary stability strong enough to carry hip joint loads experienced in the immediate rehabilitation period after THR.

Clinical and Radiological Regeneration of Large and Deep Osteochondral Defects of the Knee by Bone Augmentation Combined With Matrix-Guided Autologous Chondrocyte Transplantation.

BACKGROUND: Large osteochondral defects of the knee are a challenge for regenerative treatment. While matrix-guided autologous chondrocyte transplantation (MACT) represents a successful treatment for chondral defects, the treatment potential in combination with bone grafting by cancellous bone or bone block augmentation for large and deep osteochondral defects has not been evaluated. PURPOSE: To evaluate 1- to 3-year clinical outcomes and radiological results on magnetic resonance imaging (MRI) after the treatment of large osteochondral defects of the knee with bone augmentation and MACT. Special emphasis is placed on different methods of bone grafting (cancellous bone grafting or bone block augmentation). STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Fifty-one patients were included. Five patients were lost to follow-up. This left 46 patients (mean age, 28.2 years) with a median follow-up time of 2 years. The 46 patients had 47 deep, large osteochondral defects of the knee joint (1 patient with bilateral defects; mean defect size, 6.7 cm2). The origin of the osteochondral defects was osteochondritis dissecans (n = 34), osteonecrosis (n = 8), or subchondral cysts (n = 5). Depending on the depth, all defects were treated by cancellous bone grafting (defect depth ≤10 mm; n = 16) or bone block augmentation (defect depth >10 mm; n = 31) combined with MACT. Clinical outcomes were followed at 3 months, 6 months, 1 year, 2 years, and 3 years and evaluated using the International Knee Documentation Committee (IKDC) score and Cincinnati score. A magnetic resonance imaging (MRI) evaluation was performed at 1 and 2 years, and the magnetic resonance observation of cartilage repair tissue (MOCART) score with additional specific subchondral bone parameters (bone regeneration, bone signal quality, osteophytes, sclerotic areas, and edema) was analyzed. RESULTS: The clinical outcome scores revealed a significant increase at follow-up (6 months to 3 years) compared with the preclinical results. The median IKDC score increased from 42.6 preoperatively to 75.3 at 1 year, 79.7 at 2 years, and 84.3 at 3 years. The median Cincinnati score significantly increased from 39.8 preoperatively to 72.0 at 1 year, 78.0 at 2 years, and 80.3 at 3 years. The MRI evaluation revealed a MOCART score of 82.6 at 1 year without a deterioration at the later follow-up time point. Especially, the subchondral bone analysis showed successful regeneration. All bone blocks and cancellous bone grafts were integrated in the bony defects, and no chondrocyte transplant failure could be detected throughout the follow-up. CONCLUSION: Large and deep osteochondral defects of the knee joint can be treated successfully with bone augmentation and MACT. The treatment of shallow bony defects with cancellous bone grafting and deep bony defects with bone block augmentation shows promising results.

Wrist denervation of the posterior interosseous nerve through a volar approach: a new technique with anatomical considerations.

PURPOSE: Full or selective wrist denervation is an effective treatment for chronic wrist pain. In this cadaveric study, a volar approach for prophylactic denervation of the posterior interosseous nerve (PIN) and the anterior interosseous nerve (AIN) was assessed, which can simultaneously be performed during volar approaches for distal radius fracture fixation or in combination with metalwork removal. MATERIALS AND METHODS: In total 40 adult upper limbs, embalmed using Thiel's method, were investigated. Group 1 included 20 limbs of which the distances between AIN and PIN to the ulnar margin of radius were measured at levels 6, 8 and 10 cm proximal to the styloid process and the distance radial styloid process to proximal border of pronator quadratus which might be useful as an intraoperative landmark. Subsequently further additional 20 adult limbs (group 2) were used. Transection of the PIN via this volar approach at the evaluated best level of step 1 was performed and evaluated by dissection via a dorsal approach. RESULTS: In group 1, the PIN runs within the interosseous membrane, from the ulnar border of the radius, 6.4 mm (SD 2.66) at 6 cm, 8.4 mm (SD 2.28) at 8 cm and 3.75 mm (SD 5.46) at 10 cm proximal to the radial styloid. The AIN runs within the interosseous membrane, from the ulna edge of the radius, 7.5 mm (SD 2.4) at 6 cm, 7.3 mm (SD 1.95) at 8 cm and 2.35 mm (3.42) at 10 cm proximal to the radial styloid. AIN and PIN were in close proximity at the 8-cm level which equals a 1-cm distance proximal to the pronator quadratus border. Group 2 showed a successful transection of the PIN through a single volar surgical approach in additional 18 out of 20 adult upper limbs. CONCLUSIONS: This study shows the local anatomy of the PIN, allowing denervation via a volar approach.

Biomechanical comparison of plate and screw fixation in anterior pelvic ring fractures with low bone mineral density.

INTRODUCTION: Osteosynthesis of anterior pubic ramus fractures can be challenging, especially in poor bone quality. The aim of the present study was to compare plate and retrograde endomedullary screw fixation of the superior pubic ramus with low bone mineral density (BMD). MATERIALS AND METHODS: Twelve human cadaveric hemi-pelvises were analyzed in a matched pair study design. BMD of the specimens was 35±30mgHA/cm(3), as measured in the fifth lumbar vertebra. A simulated two-fragment superior pubic ramus fracture model was fixed with either a 7.3-mm cannulated retrograde screw (Group 1) or a 10-hole 3.5-mm reconstruction plate (Group 2). Cyclic progressively increasing axial loading was applied through the acetabulum. Relative interfragmentary movements were captured using an optical motion tracking system. RESULTS: Initial axial construct stiffness was 424±116.1N/mm in Group 1 and 464±69.7N/mm in Group 2, with no significant difference (p=0.345). Displacement and gap angle at the fracture site during cyclic loading were significantly higher in Group 1 compared to Group 2. Cycles to failure, based on clinically relevant criteria, were significantly lower in Group 1 (3469±1837) compared to Group 2 (10,226±3295) (p=0.028). Failure mode in Group 1 was characterized by screw cutting through the cancellous bone. In Group 2 the specimens exclusively failed by plate bending. CONCLUSIONS: From biomechanical point of view, pubic ramus stabilization with plate osteosynthesis is superior compared to a single retrograde screw fixation in osteoporotic bone. However, the extensive surgical approach needed for plating must be considered.

The effect of leukocyte-reduced platelet-rich plasma on the proliferation of autologous adipose-tissue derived mesenchymal stem cells.

Clinical application of platelet-rich plasma (PRP) and stem cells has become more and more important in regenerative medicine during the last decade. However, differences in PRP preparations may contribute to variable PRP compositions with unpredictable effects on a cellular level. In the present study, we modified the centrifugation settings in order to provide a leukocyte-reduced PRP and evaluated the interactions between PRP and adipose-tissue derived mesenchymal stem cells (ASCs).PRP was obtained after modification of three different centrifugation settings and investigated by hemogram analysis, quantification of protein content and growth factor concentration. ASCs were cultured in serum-free α-MEM supplemented with autologous 10% or 20% leukocyte-reduced PRP. Cell cycle kinetics of ASCs were analyzed using flow cytometric analyses after 48 hours.Thrombocytes in PRP were concentrated, whereas erythrocytes, and white blood cells (WBC) were reduced, independent of centrifugation settings. Disabling the brake further reduced the number of WBCs. A higher percentage of cells in the S-phase in the presence of 20% PRP in comparison to 10% PRP and 20% fetal calf serum (FCS) advocates the proliferation stimulation of ASCs.These findings clearly demonstrate considerable differences between three PRP separation settings and assist in safeguarding the combination of leukocyte-reduced PRP and stem cells for regenerative therapies.

Influence of preparation and football skill level on injury incidence during an amateur football tournament.

INTRODUCTION: Scientific studies on injury characteristics are rather common in professional football but not in amateur football despite the thousands of amateur football tournaments taking place worldwide each year. The purpose of this study was to evaluate the preparation and injury patterns of players of two different football skill levels who participated in an international amateur football tournament. METHODS: In a prospective cohort study, an international amateur football tournament of medical doctors in 2011 was analysed with regard to training and warm-up preparation, the level of football played before the tournament and injury data during the tournament by means of standardised injury definitions and data samples for football. RESULTS: Amateur players of registered football clubs had higher training exposure before the tournament (p < 0.001) than recreational players and had more frequently performed warm-up programmes (p < 0.001). Recreational football players showed a significantly higher overall injury incidence (p < 0.002), particularly of overuse injuries (p < 0.001), during the tournament than amateur players. In almost 75% of players in both groups, the body region most affected by injuries and complaints was the lower extremities. Orthopaedic and trauma surgeons had the lowest overall injury incidence and anaesthetists the highest (p = 0.049) during the tournament. CONCLUSION: For the first time, this study presents detailed information on the injury incidence and injury patterns of an amateur football tournament. Less-trained recreational players sustained significantly more injuries than better-trained amateur players, probably due to the lack of sufficient preparation before the tournament. Preventive strategies against overuse and traumatic injuries of recreational football players should start with regular training and warm-up programmes in preparation for a tournament.