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Background: Developmental hip dysplasia is the most common cause of secondary hip osteoarthritis. Due to severe acetabular bone deficiency, cup positioning in total hip arthroplasty (THA) of dysplastic hips remains a surgical challenge. The aim was to analyze the functional outcome of far proximal cup positions in primary THA.Methods: Fifty patients (61 hips) with THA for severe dysplastic osteoarthritis and a far proximal cup position were included. Patients were divided according to the heights of the implanted cups with increasing vertical distance from the interteardrop line (group A: 55-65 mm, group B: 65-75 mm, group C: >75 mm). Functional outcome was assessed at latest follow-up (38 ± 16 months) by Lower Extremity Functional Score, Tegner Activity Score, and Harris Hip Score (HHS). Patients answered a Patient Satisfaction Questionnaire. Leg length discrepancy was estimated radiographically.Results: The Lower Extremity Functional Score significantly decreased in C (45.3 ± 25) compared to A (66.7 ± 15.3) and B (67.9 ± 9.9). The Tegner Activity Score significantly increased in all subgroups from preoperative to postoperative (2.2 ± 1.3 to 4.1 ± 1.4; P < .05). The mean overall HHS was 89.3 ± 14.7 (A: 89.5 ± 14.3, B: 94.3 ± 6.5, C: 78.3 ± 22.1). The HHS domains of activity of daily life and gait were significantly reduced in C (P < .05). Patients described a high satisfaction level with the surgery. No significant differences were found with regard to preoperative and postoperative leg lengthening (P = .881). Neither dislocations, impingement problems nor neurologic complications were observed.Conclusion: Primary THA without any concomitant surgical interventions with a far proximal cup position offers a safe and effective treatment option in severe dysplastic hip osteoarthritis. [ABSTRACT FROM AUTHOR]

Implant loosening is frequently detected after fixation of open book injuries. Though many authors do not see this as a complication, it is often the reason for hardware removal or reinstrumentation in the case of remaining instability. We hypothesized that the flexibility of the implant has an influence on loosening and thus on failure of the construct.Methods We used 6 fresh-frozen pelvic specimens and tested them with our recently introduced test setup for two-leg alternate loading. We subjected them to a non-destructive quasi-static test in the intact condition followed by a non-destructive cyclic test under axial sinusoidal loading with progressive amplitude. Afterwards we simulated an open book injury and performed fixation with three different configurations of a modular fixation system (1-, 2- or 4-rod configuration) in randomized order. Subsequently, the specimens were subjected to 3 cyclic tests with the same loading protocol as previously defined. Finally, each construct was cyclically tested to failure keeping the final rod configuration.Findings We detected significantly greater mobility after 1-rod-fixation and no significant differences after 2-rod or 4-rod-fixation compared to the intact symphysis condition. In the destructive test series the 4-rod-fixation failed first followed by the 1-rod-fixation. The 2-rod-fixation sustained almost 3 times as many load cycles prior to failure as the 4-rod-fixation, whereas the 1-rod-fixation sustained twice as many cycles as the 4-rod-fixation.Interpretation In conclusion, flexible fixation of the ruptured pubic symphysis in human specimens shows superior behavior with respect to load bearing capacity and ability to withstand cyclic loading compared to stiff constructs. [ABSTRACT FROM AUTHOR]

Background: Non-unions and chronic instability of the pelvis remain rare complications after complex high velocity injuries with vertical and rotational instability of the pelvis. Treatment options are insufficiently supported by data evidence due to the rareness of this condition.Patients and Methods: we conducted a single center, retrospective study of all non-unions and pelvic instabilities between 1.1.2008 and 1.1.2019, excluding fragility fractures. Patients' characteristics, fracture patterns, procedures and outcomes with regard to developing treatment options and successful union in the follow-up were obtained.Results: 26 patients were included in this retrospective analysis. The mean age was 55 years (range 34-78 years). Seventy-seven percent of the patients were male. The standard procedure consisted of radical debridement of the non-union, interposition of autologous bone graft and rigid stabilization systems. Three patients were lost to follow up. In the remaining n = 23 patients (88%) consolidation of the non-union was achieved. The mean follow up was 31.3 months (range 6-144). Follow up showed that an iliolumbar fixation seems to be favorable regarding outcome and complications.Discussion: Non-union and remaining instability of the pelvic ring represent a rare complication after high grade pelvic trauma. There are only limited data regarding the incidence and the treatment regimen is based on small study populations only. Based on our findings we recommend to combine autologous bone grafts with rigid fixation systems especially for non-union of the pelvis to restore the posterior sacroiliac arch. [ABSTRACT FROM AUTHOR]

Intraoperative imaging has been advanced substantially over the last decades. It supports localization of the region of interest, verification of the preoperatively classified fracture pattern, identification of correct insertion point of the implant, placement of instruments and fixation material, and verification of correct fracture reduction and implant positioning. While conventional fluoroscopic 2D imaging remains the gold standard in intraoperative imaging, critical anatomical regions are predestined for intraoperative 3D imaging. Additional options such as perioperative virtual planning, simulation, and surgical training, 3D printing techniques and 3D augmented reality visualization may potentially open new windows to improve surgical results in fracture care. This manuscript presents an update on current and upcoming imaging techniques in orthopaedic and trauma surgery focusing on technical advances for decreasing malreduction, malalignment, and malposition, as well as tips and tricks for daily surgical practice in order to improve clinical outcomes and patients' and surgeons' safety. [ABSTRACT FROM AUTHOR]

Background: Fractures of the acetabulum are rare injuries. The indication for surgical stabilization depends on the grade of instability and dislocation. Exact knowledge of the different possible surgical approaches is essential for the planning of the surgical treatment. Both, knowledge of anatomical structures and possible risks of the different approaches, are important.Methods: Over a period of 15 years, we analyzed all patients with acetabular fractures, treated in our Level I Trauma Center with special interest in surgical and approach-related complications. Based on our complication rates, we describe the used different surgical approaches and the accessible anatomical structures respectively. Finally, we focus on strategies to reduce the risk of approach-related complications in acetabular surgery.Results: Between January 2003 and December 2017, 523 patients with an acetabular fracture were treated in our Tertiary Referral Hospital. Of these, 101 patients had at least one complication, resulting in an overall complication rate of 19.3%. 296 patients underwent surgical treatment of the acetabular fracture, while 227 patients were treated non-operatively. Surgically treated patients had a significantly higher complication rate of 21.2% (63/296) compared to conservatively treated patients with a complication rate of 16.7% (38/227). Neurovascular and thromboembolic adverse events were the most often complications.Conclusions: Patients with acetabular fractures are at a high risk for different kind of complications. The most common risks are neuro-vascular and thromboembolic incidents. The risk of getting a complication is increased in surgically treated patients, therefore both the indication for surgical treatment and the surgical approach should be carried out carefully, including individual patient parameters and fracture types as well as the surgeons expertise. [ABSTRACT FROM AUTHOR]

The dorsal component of the pelvic ring is considered to be the most essential element for the stability of the pelvic ring. None of the current biomechanical set-ups include the effect of shear stresses by alternating loads that the pelvic ring has to withstand during walking. We hypothesize that a biomechanical test set-up with two-leg alternate loading will lead to stress imitation at the pubic symphysis that are more similar to existing strains than other test set-ups, and would, therefore, be more adequate for biomechanical testing of fixation methods. A new biomechanical two-leg standing test set-up with an alternate pelvic loading was constructed and was validated with six human pelvises from fresh frozen cadavers. Three-dimensional motion tracking was performed. The specimens were subjected to a non-destructive quasi-static test and a non-destructive cyclic test with progressive load amplitude from 170 N to 340 N over 1000 cycles. The initial rotational 'range of motion' and 'mean displacement' around the vertical axis for a pre-load of 170 N was about 0.3° and 0.2°, respectively, increasing by 0.1-0.2° at a load of 340 N. The rotation around the vertical axis and the translation along the frontal horizontal axis confirmed the stability of the pubic symphysis. The rate of ascend of displacements decreased, once the rotation reached 1° or the translation reached 1 mm. The current biomechanical test set-up was compared with previous clinical findings, and the method was found valid for measuring inter-segmentary movements at the pubic symphysis. [ABSTRACT FROM AUTHOR]