Fracture reduction and screw position after 3D-navigated and conventional fluoroscopy-assisted percutaneous management of acetabular fractures: a retrospective comparative study.

BACKGROUND: Navigational techniques in orthopaedic trauma surgery have developed over the last years leaving the question of really improving quality of treatment. Especially in marginal surgical indications, their benefit has to be evident. The aim of this study was to compare reduction and screw position following 3D-navigated and conventional percutaneous screw fixation of acetabular fractures. The study hypothesis postulated that better fracture reduction and better screw position are obtained with 3D navigation. MATERIALS AND METHODS: Preoperative and postoperative CT scans of 37 acetabular fractures treated by percutaneous screw fixation (24 3D-navigated, 13 conventional) were evaluated. Differences in pre- and postoperative fracture gaps and steps were compared in all reconstructions as well as the screw position relative to the joint and the fracture. RESULTS: The differences in fracture gaps and fracture steps with and without 3D navigation were not significantly different. Distance of the screw from the joint line, angle difference between screw and ideal angle relative to the fracture line, length of the possible corridor used and position of the screw thread did not show any significant differences. CONCLUSION: Comparison of 3D-navigated and conventional percutaneous surgery of acetabular fractures on the basis of pre- and postoperative CTs revealed no significant differences in terms of fracture reduction and screw position.

Diagnostic accuracy of intraoperative CT-imaging in complex articular fractures - a cadaveric study.

Anatomic reconstruction of articular fractures is one of the critical factors in later achieving good functional outcome. Intraoperative 3D imaging has been shown to offer better evaluation and therefore can significantly improve the results. The purpose of this study was to assess the difference between intraoperative three-dimensional fluoroscopy (3D) and intraoperative computed tomography (iCT) imaging regarding fracture reduction, implant placement and articular impressions in a distal humeral fracture model. AO type 13-B2 fracture pattern were created in upper extremity cadaver specimens. Articular step-offs, intra-articular screw placement and intraarticular impressions of different degrees of severity were created. All specimens had imaging performed. For each articular pattern 3D fluoroscopy in standard (3Ds) and high quality (3Dh) were performed (Arcadis Orbic, Siemens, Germany) as well as an intraoperative CT scan (iCT, Airo, Brainlab, Germany). Three observers evaluated all imaging studies regarding subjective and objective parameters. iCT is more precise than 3D fluoroscopic imaging for detection of articular impressions. Articular step-offs and intraarticular screw placement are similar for iCT and 3D. Subjective imaging quality is the highest for iCT and lowest for 3Ds. Intraoperative CT may be particularly useful in assessing articular impressions and providing a good subjective image quality for the surgeon.

Mid-term results of anatomical total shoulder arthroplasty for primary osteoarthritis using a short-stemmed cementless humeral component.

Aims: The aim of this study was to evaluate the clinical and radiological outcome of using an anatomical short-stem shoulder prosthesis to treat primary osteoarthritis of the glenohumeral joint. Patients and Methods: A total of 66 patients (67 shoulders) with a mean age of 76 years (63 to 92) were available for clinical and radiological follow-up at two different timepoints (T1, mean 2.6 years, sd 0.5; T2, mean 5.3 years, sd 0.7). Postoperative radiographs were analyzed for stem angle, cortical contact, and filling ratio of the stem. Follow-up radiographs were analyzed for timing and location of bone adaptation (cortical bone narrowing, osteopenia, spot welds, and condensation lines). The bone adaptation was classified as low (between zero and three features of bone remodelling around the humeral stem) or high (four or more features). Results: The mean Constant score improved significantly from 28.5 (sd 11.6) preoperatively to 75.5 (sd 8.5) at T1 (p < 0.001) and remained stable over time (T2: 76.6, sd 10.2). No stem loosening was seen. High bone adaptation was present in 42% of shoulders at T1, with a slight decrease to 37% at T2. Cortical bone narrowing and osteopenia in the region of the calcar decreased from 76% to 66% between T1 and T2. Patients with high bone adaptation had a significantly higher mean filling ratio of the stem at the metaphysis (0.60, sd 0.05 vs 0.55, sd 0.06; p = 0.003) and at the diaphysis (0.65 sd 0.05 vs 0.60 sd 0.05; p = 0.007). Cortical contact of the stem was also associated with high bone adaptation (14/25 shoulders, p = 0.001). The clinical outcome was not influenced by the radiological changes. Conclusion: Total shoulder arthroplasty using a short-stem humeral component resulted in good clinical outcomes with no evidence of loosening. However, approximately 40% of the shoulders developed substantial bone loss in the proximal humerus at between four and seven years of follow-up. Cite this article: Bone Joint J 2018;100-B:603-9.

2D projection-based software application for mobile C-arms optimises wire placement in the proximal femur - An experimental study.

PURPOSE: A new software application can be used without fixed reference markers or a registration process in wire placement. The aim was to compare placement of Kirschner wires (K-wires) into the proximal femur with the software application versus the conventional method without guiding. As study hypothesis, we assumed less placement attempts, shorter procedure time and shorter fluoroscopy time using the software. The same precision inside a proximal femur bone model using the software application was premised. METHODS: The software detects a K-wire within the 2D fluoroscopic image. By evaluating its direction and tip location, it superimposes a trajectory on the image, visualizing the intended direction of the K-wire. The K-wire was positioned in 20 artificial bones with the use of software by one surgeon; 20 bones served as conventional controls. A brass thumb tack was placed into the femoral head and its tip targeted with the wire. Number of placement attempts, duration of the procedure, duration of fluoroscopy time and distance to the target in a postoperative 3D scan were recorded. RESULTS: Compared with the conventional method, use of the application showed fewer attempts for optimal wire placement (p=0.026), shorter duration of surgery (p=0.004), shorter fluoroscopy time (p=0.024) and higher precision (p=0.018). Final wire position was achieved in the first attempt in 17 out of 20 cases with the software and in 9 out of 20 cases with the conventional method. CONCLUSIONS: The study hypothesis was confirmed. The new application optimised the process of K-wire placement in the proximal femur in an artificial bone model while also improving precision. Benefits lie especially in the reduction of placement attempts and reduction of fluoroscopy time under the aspect of radiation protection. The software runs on a conventional image intensifier and can therefore be easily integrated into the daily surgical routine.

[Three-dimensional correction of the thoraco-lumbar spine after sarcoma resection : An inter-disciplinary approach with free-tissue transfer]. / Dreidimensionale Korrektur der thorakolumbalen Wirbelsäule nach Resektion eines Sarkoms : Interdisziplinärer Ansatz mit freiem Gewebetransfer.

This article presents the case of a high-grade deformity of the thoraco-lumbar spine. The patient suffered from a sarcoma that was radically resected. Due to adjuvant radiation, the patient suffered from a radiation injury with chronic fistula. In a two-stage approach, the deformity was corrected by a closing-wedge osteotomy of L3 with elongation of the present dorsal spondylodesis (Th10-L4) to Th8 and the iliac bone. Soft-tissue reconstruction was achieved by a free latissimus dorsi flap that was anastomosed to an axillary arterio-venous loop. The presented interdisciplinary approach allowed an almost complete correction of the deformity and stable soft-tissue coverage.

[3D safety in osteosynthesis adjacent to joints]. / 3-D-Sicherheit bei gelenknahen Osteosynthesen.

BACKGROUND: The results and immediate consequences of intraoperative three-dimensional (3D) imaging in the treatment of AO classification type C fractures of the distal radius, the tibial head and the tibial pilon were analyzed and compared with published results on general intraoperative revision rates following intraoperative 3D-imaging. METHODS: In this retrospective study 279 patients with AO type C fractures of the distal radius (n = 84), tibial head (n = 109) and tibial pilon (n = 86) who underwent intraoperative 3D-imaging were included. The findings of the 3D-imaging and the intraoperative revision rates were analyzed and compared with previously published results of our working group. RESULTS: In 70 out of 279 patients (25 %) an intraoperative revision was carried out following 3D-imaging. The revision rates were 15 % for fractures of the distal radius, 27 % for fractures of the tibial head and 32 % for fractures of the tibial pilon. The most common reason for immediate intraoperative revision was the necessity for improved repositioning due to a remaining step in the articular surface in 51 out of 279 patients (18%). CONCLUSION: Intraoperative revision rates following 3D-imaging increased with the severity of the injury pattern. Intraoperative 3D-imaging should be routinely used in the treatment of fractures of the tibial head, tibial pilon and even in comminuted distal radius fractures due to the high intraoperative revision rates found in the present study. Alternatively, a postoperative computed tomography (CT) control should be performed.

[Postoperative implant-associated osteomyelitis of the shoulder: Hardware-retaining revision concept using temporary drainage]. / Postoperative implantatassoziierte Osteitis am Schultergürtel: Materialerhaltendes Revisionskonzept mit Einlage einer Dauerdrainage.

BACKGROUND: Posttraumatic and postoperative osteomyelitis (PPO) is a subgroup of bone infections with increasing importance. However, to date no standardized reoperation concept exists particularly for patients with PPO of the shoulder region. Therefore the purpose of this study was to evaluate a revision concept including débridement, irrigation, and insertion of temporary drainage with hardware retention until healing. PATIENTS AND METHODS: A total of 31 patients with PPO were included with a proximal humerus fracture (n = 14), clavicle fracture (n = 10), or AC-joint separation (n = 7). In all, 27 of these patients could be followed for > 1 year. RESULTS: Hardware retention until fracture or ligament healing could be achieved in > 83%. Six patients required follow-up débridement due to recurrent infections, but then were unremarkable. Clinical outcome showed excellent Constant scores (91.6 ± 2.8). CONCLUSION: A cost-efficient, simple, and successful revision concept for patients with PPO of the shoulder region is described.

[High bone consolidation rates after humeral head-preserving revision surgery in non-unions of the proximal humerus]. / Hohe knöcherne Ausheilungsraten nach kopferhaltender Revision von proximalen Humeruspseudarthrosen.

BACKGROUND: Fractures of the subcapital and proximal humerus shaft region are common fractures of the human skeleton. Their treatment should provide an early functional after-care of the shoulder joint, that is prone to arthrofibrosis. Although the upper extremity is not weight-bearing the occurrence of proximal humerus non-unions leads to severe impairment with inability to work and restrictions of activity of daily life. The aim of this study was to investigate whether an operative revision of proximal humerus non-unions with reosteosynthesis and application of distant autologous bone grafts can lead to sufficient bone healing. The second aim was to find out whether patients achieved an acceptable functional outcome, as alternatively patients could be treated by reconstruction with a shoulder prosthesis. PATIENTS AND METHODS: 27 patients (female = 15, male = 12) with reosteosynthesis of the proximal humerus and proximal humeral shaft due to non-union after initially operative fracture treatment were included between 2008 and 2014. Average age of patients was 56 years (23-87), 48% had no comorbidities, while 52% of the patients had at least 1 comorbidity such as diabetes, hypertension or nicotine abusus. The mean number of prior surgical intervention was 1.2 (1-3). The mean time between initial surgery and re-osteosynthesis was 12.3 months. Patients with signs of infection pseudarthrosis were excluded. The initial type of osteosynthesis was with plates (n = 16; thereof PHILOS Plate n = 14), and intramedullary nails (T2, Targon Nail, PHN, Seidel Nail; n = 11). Revision surgery was done with plate osteosynthesis (n = 26; thereof PHILOS Plate n = 4; LC Plate n = 10; angle plate n = 12). In 23 patients (89%) a distant bone transplantation was done from the iliac crest, and 1 patient received allogenous bone. Three patients (11%) received bone morphogenetic protein 7 (BMP 7) in combination with distant bone graft. Intraoperative swabs from the pseudarthrosis area showed no bacterial pathogen after 14 days of incubation. DASH score and Constant score were used to evaluate the functional outcome after revision surgery. Bone healing was determined by standard X-rays and evaluated by a modified radiological score. RESULTS: 89% of the patients could be followed for an average of 28 months and the radiological follow-up was at 9 months. The radiological score showed very good (50%), or good results, and a sufficient bone healing was shown in 25 of 27 patients (93%). The pseudarthrosis revision surgery failed in two cases (n = 1 persisting non-union; n = 1 humeral head necrosis after re-operation with angle plate). DASH scores provided a mean of 40 ± 28.8 with a range from 0-97 points, and the results from the Constant score provided 45 ± 25.4. The analysis with variation of age showed a trend for better results in female patients < 60 years of age. As complications after bone graft 3 patients had persistent local dysesthesia (11%), in one case fracture of the iliac bone occurred that healed with conservative treatment. CONCLUSION: The pseudarthrosis revision surgery with humeral head preserving re-osteosynthesis with bone transplantation is an effective treatment for non-unions of the proximal humerus and the proximal humeral shaft and the current results showed high bone consolidation rates. As the functional results remained limited after revision an individual treatment decision should be made concerning the most appropriate therapy. While a shoulder prosthesis may be considered in the aged patient, a revision strategy with reosteosynthesis should be considered particularly in younger patients.