Background: We aimed to evaluate the impact of knee periprosthetic joint infection (PJI) by assessing the patients’ long-term quality of life and explicitly their psychological wellbeing after successful treatment. Methods: Thirty-six patients with achieved eradication of infection after knee PJI were included. Quality of life was evaluated with the EQ-5D and SF-36 outcome instruments as well as with an ICD-10 based symptom rating (ISR) and compared to normative data. Results: At a follow-up of 4.9 ± 3.5 years the mean SF-36 score was 24.82 ± 10.0 regarding the physical health component and 46.16 ± 13.3 regarding the mental health component compared to German normative values of 48.36 ± 9.4 (p < 0.001) and 50.87 ± 8.8 (p = 0.003). The mean EQ-5D index reached 0.55 ± 0.33 with an EQ-5D VAS rating of 52.14 ± 19.9 compared to reference scores of 0.891 (p < 0.001) and 68.6 ± 1.1 (p < 0.001). Mean scores of the ISR revealed the psychological symptom burden on the depression scale. Conclusion: PJI patients still suffer from significantly lower quality of life compared to normative data, even years after surgically successful treatment. Future clinical studies should focus on patient-related outcome measures. Newly emerging treatment strategies, prevention methods, and interdisciplinary approaches should be implemented to improve the quality of life of PJI patients.

Persistent pain around the greater trochanter is a common complication after total hip arthroplasty. Restoration of biomechanics such as leg length, femoral und acetabular offset is crucial in THA. The purpose of this study was to evaluate postoperative differences of these parameters after THA and to analyze their association to greater trochanteric pain syndrome. Furthermore, we aimed to evaluate the clinical relevance of trochanteric pain syndrome compared to patient reported outcome measures. 3D-CT scans of 90 patients were analyzed after minimalinvasive total hip arthroplasty and leg length, femoral and acetabular offset differences were measured. Clinical evaluation was performed three years after THA regarding the presence of trochanteric pain syndrome and using outcome measures. Furthermore, the patients’ expectation were evaluated. Patients with trochanteric pain syndrome showed a higher absolute discrepancy of combined leg length, femoral and acetabular offset restoration compared to the non-operated contralateral side with 11.8 ± 6.0 mm than patients without symptoms in the trochanteric region with 7.8 ± 5.3 mm (p = 0.01). Patients with an absolute deviation of the combined parameters of more than 5 mm complained more frequently about trochanteric symptoms (29.2%, 19/65) than patients with a biomechanical restoration within 5 mm compared to the non-affected contralateral side (8.0%, 2/25, p = 0.03). Clinical outcome measured three years after THA was significantly lower in patients with trochanteric symptoms than without trochanteric pain (p < 0.03). Similarly, fulfillment of patient expectations as measured by THR-Survey was lower in the patients with trochanteric pain (p < 0.005). An exact combined restoration of leg length, acetabular and femoral offset reduces significantly postoperative trochanteric pain syndrome and improves the clinical outcome of the patients.

Unicompartimental and total knee arthroplasty is one of the most successful and most performed operations worldwide. In the last years the number of primary knee arthroplasty increased constantly. The aim of this study is to analyze the rising numbers of primary knee arthroplasty and to see how it is used in Germany. In this retrospective study data, provided by the Federal Statistical Office of Germany from 2008 to 2018 was analyzed, using operation codes from the German procedure classification system and characteristics like age, sex and type of the prosthesis. We found a slight increase of unicompartimental and total knee arthroplasty over the investigated 10 years from 150.504 in 2008 up to 168.479 procedures in 2018, with a maximum of 169.334 in 2017. Most patients were female and over 65 years old. Interestingly, there was an obvious decrease of regular TKA in the year 2013, with a relevant impact on the total number of procedures. In the following years the number rised again reaching the former level in 2015 and is still increasing. The highest increase was found in partial knee arthroplasty, with a constant rise every year, starting with 7988 in 2008 up to 21.072 in 2018. In contrast, we found a relevant reduction of constrained prosthesis in primary TKA, whereas the number of semi-constrained prosthesis in primary TKA is again rising after a decrease in 2015. We found that the number of bicondylar TKA and especially UKA increased from 2008 to 2018. Regarding an aging population, we can expect a rising number for Primary knee arthroplasty and in consequence a rising number of revision arthroplasty in the future. This will be a challenging cost factor for the healthcare system in Germany.

Due to demographic changes, more and more fracture patterns involving anterior acetabular structures occur. The infra-acetabular screw is seen a useful tool to increase stability in fixation of the acetabular cup. However, the exact position of this screw in relation to anatomic landmarks which are intra-operatively palpable via an intra-pelvic approach has not yet been determined. This biomorphometric experimental study references the ideal screw position of an infra-acetabular screw to anatomic landmarks palpable via an intra-pelvic approach. Therefore, we created a computer tomography-based 3D-model of 40 patients (20 women, 20 men) who received a computer tomography (CT) scan of the pelvis for any other reason than an acetabular fracture. The entry point of an ideal infra-acetabular was of high constancy. At mean, this point was 10.2 mm caudal and 10.4 mm medial of the ilio-pubic/ilio-pectineal eminence. This reference is independent of age, gender, or physical dimensions. However, we found gender-dependent differences for the angulation and the length of the screw. This study provides a comprehensive guideline to determine the ideal entry point for an infra-acetabular screw via an intra-pelvic approach. The entry point is located 10.2 mm caudal and 10.4 mm medial of the ilio-pubic/ilio-pectineal eminence. Clinical Trial Registry University of Regensburg Z-2017-0930-1 . Registered 04. Dec 2017.

Improper femoral and acetabular component positioning can be associated with instability, impingement, component wear and finally patient dissatisfaction in total hip arthroplasty (THA). The concept of “femur first”/“combined anteversion”, incorporates various aspects of performing a functional optimization of the prosthetic stem and cup position of the stem relative to the cup intraoperatively. In the present study we asked two questions: (1) Do native femoral anteversion and anteversion of the implant correlate? (2) Do anteversion of the final broach and implant anteversion correlate? In a secondary analysis of a prospective controlled trial, a subgroup of 55 patients, who underwent computer-assisted, cementless THA with a straight, tapered stem through an anterolateral, minimally invasive (MIS) approach in a lateral decubitus position were examined retrospectivly. Intraoperative fluoroscopy was used to verify a “best-fit” position of the final broach. An image-free navigation system was used for measurement of the native femoral version, version of the final broach and the final implant. Femoral neck resection height was measured in postoperative CT-scans. This investigation was approved by the local Ethics Commission (No.10-121-0263) and is a secondary analysis of a larger project (DRKS00000739, German Clinical Trials Register May-02–2011). The mean difference between native femoral version and final implant was 1.9° (+/− 9.5), with a range from −20.7° to 21.5° and a Spearman’s correlation coefficient of 0.39 (p < 0.003). In contrast, we observed a mean difference between final broach and implant version of −1.9° (+/− 3.5), with a range from −12.7° to 8.7° and a Spearman’s correlation coefficient of 0.89 (p < 0.001). In 83.6 % (46/55) final stem version was outside the normal range as defined by Tönnis (15-20°). The mean femoral neck resection height was 7.3 mm (+/− 5.6). There was no correlation between resection height and version of the implant (Spearman’s correlation coefficient 0.14). Native femoral version significantly differs from the final anteversion of a cementless, straight, tapered stem and therefore is not a reliable reference in cementless THA. Measuring anteversion of the final “fit and fill” broach is a feasible assistance in order to predict final stem anteversion intraoperatively. There is no correlation between femoral neck resection height and version of the implant.

Clinical and radiological outcomes of operatively treated unstable pelvic ring fractures are well documented, whereas little is known about the patient’s related outcome. The purpose of this study is to evaluate the patient-reported outcome after minimal invasive treatment of pelvic ring fractures using the SF-36 and EQ-5D medical outcome scores. Patients with unstable pelvic ring fractures treated in our trauma department with a minimal invasive screw-rod system between 01/2004 and 12/2014 were included. Next to patient data (sex, age), injury related details (fracture type, additional injuries, Injury Severity Score (ISS)) as well as operation details (method, time to operation, general complications, adverse events associated with the surgical procedure, revision surgery, fracture reduction) were assessed. The patient related outcome was evaluated using the SF-36 and the EQ-5D score. A total of 105 patients (57 men; 48 women; mean age 56 ± 21 years) were identified as candidates for the study. 60 patients completed the SF-36 and EQ-5D score after a mean follow-up of five years (60.5 months (14-142 months)). Of these patients 77% were multiply injured with a mean ISS of 26 ± 19. Within the respondent group 22% showed type B and 78% type C pelvic ring fractures. In 82% the dorsal pelvic ring fracture was stabilized using a minimally invasive transiliac internal fixator, in 18% an iliolumbar fixation was performed respectively. The mean physical component score of the SF-36 was 37.9 ± 12.0, the mean mental component score was 49.8 ± 12.5. The mean EQ-5D VAS reached 70.5 ± 24.4. Patients being multiply injured and treated with minimal invasive treated dorsal pelvic ring fractures were suffering more especially concerning physical domains compared to the healthy reference population. Nevertheless, the overall patient-related outcome is comparable to pelvic ring fractures in general. Clinical Trial Registry University of Regensburg Z-2017-0878-3 . Registered 22. July 2017. Retrospectively registered.