Evidence of Bacterial Metabolism in Synovial Fluid of Patients With Graft Failure After Anterior Cruciate Ligament Reconstruction: A Microbiological Comparison of Primary Anterior Cruciate Ligament and Hamstring Tendon Autograft Ruptures.

PURPOSE: To investigate whether the bacterial presence in a primary ruptured native anterior cruciate ligament (ACL) differs from that in a ruptured hamstrings ACL autograft and whether low-grade infections cumulatively can be detected in the case of graft failure. METHODS: In a retrospective case-control study with prospectively collected data, synovial fluid aspirates and tissue samples of failed ACL grafts were examined for evidence of bacterial colonization and compared to samples of the native ACL in primary ACL reconstruction (ACLR) using microbiological culture, 16S rRNA-PCR and histopathological examination. Furthermore, synovial fluid aspiration was investigated for possible future biomarkers for a low-grade infection. RESULTS: A total of 112 consecutive patients undergoing primary ACLR without history of previous surgeries to the affected knee (n = 59) and revision ACLR after reconstruction with a hamstring tendon autograft (n = 53) were recruited from one center. No patient had a history or showed clinical signs of infection. A total of 389 samples were analyzed by culture. Bacteria were detected in 9.4% of patients with a graft rupture (n = 5/53) compared to 3.4% of patients with a primary ACL rupture (n = 2/59) showing no statistical difference (P = .192). One patient with a "true" low-grade infection was found in our study population, resulting in a prevalence of 1.9% (1/53) in the graft group. The percentage of polymorphonuclear leukocytes (PMN%) as a highly sensitive marker for joint infections was significantly higher in aspirated synovial fluid of graft ruptures (27% ± 3% vs 20% ± 4%; P = .032), as well as glucose levels were significantly lower (83 mg/dL ± 2 mg/dL vs 88 mg/dL ± 2 mg/dL; P = .042). CONCLUSIONS: Synovial fluid obtained before revision ACLR showed a higher percentage of polymorphonuclear leukocytes and lower glucose levels compared with primary ACLR, suggesting bacterial metabolism and demonstrating that the intra-articular milieu changes significantly after ACLR. Tissue samples of ACL grafts revealed a low-grade infection in one case, although overall cultivable bacterial presence did not differ significantly when compared to samples of a native ACL. LEVEL OF EVIDENCE: Level III, retrospective case-control study.

Semitendinosus tendons are commonly contaminated with skin flora during graft harvest for anterior cruciate ligament reconstruction.

PURPOSE: To investigate the rate of bacterial contamination of semitendinosus (ST) tendons during graft harvest in anterior cruciate ligament reconstruction (ACLR), in order to precisely specify the underlying pathogens and obtain data on their susceptibility to potential antibiotics. METHODS: In a prospective study, a total of 59 consecutive patients undergoing primary ACLR were recruited from one centre. No patient had history of previous surgery to the knee or showed clinical signs of infection. Four tissue samples of harvested ST tendons for anterior cruciate ligament (ACL) autografts (case group; ST) were examined for evidence of bacterial colonisation and compared to four tissue samples of the native ACL as negative controls (control group; ACL). Three of the respective samples were subjected to cultural microbiological examination and one to 16S rRNA-PCR. Antibiotic susceptibility testing was performed for each pathogen that was identified. RESULTS: A total of 342 samples were analysed by culture. Significantly more patients showed a positive culture of the ST (33.9%; n = 20/59) compared to 3.4% of patients (n = 2/59) with positive culturing of the ACL (p < 0.0001). Including 16S rRNA-PCR, in a total of 42.4% (25/59) of patients, bacteria were detected in at least one ST sample either by PCR and/or culture. All species found (n = 33) belong to the typical skin flora with Staphylococcus epidermidis (39.4%; n = 13/33) being the most common species, followed by Staphylococcus capitis (24.2%; n = 8/33). All tested isolates (n = 29) were susceptible to vancomycin (29/29, 100%), 69% (n = 20/29) to oxacillin and 65.5% (n = 19/29) to clindamycin. CONCLUSION: ST autografts for ACLR were commonly contaminated with skin commensal bacteria during harvest. One-third of the isolates showed resistance to typical perioperative intravenous antibiotics, whereas all isolates were sensitive to vancomycin. Therefore, routine prophylactic decontamination of all hamstring autografts before implantation should be recommended, preferably with topical vancomycin. LEVEL OF EVIDENCE: Level III.

Current status of the management of isolated syndesmotic injuries in Germany.

INTRODUCTION: Although non-fracture-related syndesmotic injuries of the ankle are relatively rare, they may lead to poor clinical outcome if initially undiagnosed or managed improperly. Despite a variety of literature regarding possibilities for treatment of isolated syndesmotic injuries, little is known about effective applications of different therapeutic methods in day-to-day work. The aim of this study was to assess the current status of the treatment of isolated syndesmotic injuries in Germany. MATERIALS AND METHODS: An online-questionnaire, capturing the routine diagnostic workup including clinical examination, radiologic assessment and treatment strategies, was sent to all members of the German Society of Orthopedic Surgery and Traumatology (DGOU) and Association of Arthroscopic and Joint Surgery (AGA). Statistical analysis was performed using Microsoft excel and SPSS. RESULTS: Each question of the questionnaire was on average answered by 431 ± 113 respondents. External rotation stress test (66%), squeeze test (61%) and forced dorsiflexion test (40%) were most commonly used for the clinical examination. In the diagnostic workup, most clinicians relied on MRI (83%) and conventional X-ray analysis (anterior-posterior 58%, lateral 41%, mortise view 38%). Only 15% of the respondents stated that there is a role for arthroscopic evaluation for the assessment of isolated syndesmotic injuries. Most frequently used fixation techniques included syndesmotic screw fixation (80%, 42% one syndesmotic screw, 38% two syndesmotic screws), followed by suture-button devices in 13%. Syndesmotic screw fixation was mainly performed tricortically (78%). While 50% of the respondents stated that syndesmotic screw fixation and suture-button devices are equivalent in the treatment of isolated syndesmotic injuries with respect to clinical outcome, 36% answered that syndesmotic screw fixation is superior compared to suture-button devices. CONCLUSIONS: While arthroscopy and suture-button devices do not appear to be widely used, syndesmotic screw fixation after diagnostic work-up by MRI seems to be the common treatment algorithm for non-fracture-related syndesmotic injuries in Germany.

Epidemiology of Injuries in Olympic Sports.

Injuries effect the performance of athletes. Severity of injuries is determined by time loss and sporting performance reduction. To treat injuries adequately, it is necessary to get an overview of varied injuries types in different sports disciplines. In a retrospective study 7.809 athletes from Germany, Switzerland and Austria competing in competitive or recreational levels of sports were included. Injury prevalence was highest in team sports (75%), followed by combat (64%), racquet (54%) and track and field (51%). Knee (28%) and shoulder (14%) were the most at risk joints. Time loss in sporting activity after injury was longest in the region of knee (26 weeks). Of all reported injuries, 48% were accompanied by a reduced level of performance. The highest injury prevalence occurred in the year 2016 (45%). More injuries occurred during training (58%) compared to competition (42%). Across Olympic disciplines, a large number of injuries occurred during training sessions. Injury frequency increased as the Olympic games drew closer. Knee and shoulder injuries were the most severe injuries with respect to time loss and reduction sporting performance.

Side Differences Regarding the Limb Symmetry Index in Healthy Professional Athletes.

Side differences in the limb symmetry index during hop tests have been rarely investigated in uninjured athletes. Unknown differences can result in false interpretation of hop tests and affect return to sport decision. Hypothesis was that un-injured athletes in Judo and Taekwondo have side differences in hop test and that asymmetries can be predicted based on the athletes fighting display. Differences, risk relationships were analyzed using the chi-squared test and the odds ratio. A two-tailed p value of<0.05 was considered statistically significant. 115 athletes from the national teams were included (mean age 18.4 years; range 13-27 years). 93, 97.4 and 98.3% did not have symmetric hop distance for three hop tests. Up to a quarter did not reach a limb symmetry index of>90. Moreover, 57.4% (n=66) reached longer jumping distance with the standing leg. Ignoring such pre-existent side differences in evaluation of hop tests and not knowing which limb was dominant prior the injury, can lead to premature or delayed return to sports in the rehabilitation process. Therefore, it might be helpful to refer to individual jump lengths for each limb in case of injury by using hop tests in pre-season screening in professional athletes in Judo and Taekwondo.

Tactile techniques are associated with a high variability of tunnel positions in lateral extra-articular tenodesis procedures.

INTRODUCTION: The purpose of this study was to determine the variability of femoral tunnel positions applying two different lateral extra-articular tenodesis (LET) techniques, guiding on the tactile identification (1) of the lateral epicondyle (Lemaire procedure) and (2) of the Kaplan fibre attachments on the distal femur (MacIntosh procedure) and to analyse whether one of these procedures is more suitable for reliable femoral tunnel positioning in LET procedures. MATERIALS AND METHODS: Two experienced knee surgeons determined femoral tunnel positions in ten fresh-frozen cadaveric knee specimens according to the modified Lemaire and MacIntosh techniques. Tunnel positions were measured on true lateral radiographs as absolute distances from the posterior cortex line (anterior-posterior direction) and from a perpendicular line intersecting the contact of the posterior femoral condyle (proximal-distal direction), respectively. Further, tunnel positions were measured relatively to the femur height. An independent F test was used to compare variances between Lemaire and MacIntosh tunnel positions and between anterior-posterior and proximal-distal directions. RESULTS: The mean Lemaire and MacIntosh positions were found 2.7 ± 5.5 mm and 3.6 ± 3.4 mm anterior to the posterior cortex line, and 7.5 ± 5.0 mm and 17.3 ± 6.9 mm proximal to the perpendicular line intersecting the contact of the posterior femoral condyle, respectively. Mean Lemaire and MacIntosh positions, relative to the femur height, were found at 8.8% and 10.9% (anterior-posterior) and 22.2% and 50.8% (proximal-distal), respectively. Variability in tunnel positioning was observed for both techniques, showing no significant differences in the variance (p > 0.05) and partially overlapping tunnel positions of both techniques. The overall variance of tunnel positions, however, was significantly greater in proximal-distal than in anterior-posterior direction (F = 2.673, p < 0.038). CONCLUSIONS: Femoral tunnel positions in LET procedures have a high degree of variability and inaccuracy. Palpating anatomic landmarks appears to be insufficient to generate reproducible tunnel positions. Radiographic landmarks may enable more reproducible identification of isometric femoral tunnel positions and reduce malpositioning.

Radiographic images are inapplicable for a precise evaluation of the femoral tunnel position following MPFL reconstruction.

PURPOSE: In medial patellofemoral ligament (MPFL) reconstruction, it remains controversial whether more accurate femoral tunnel positioning is correlated with improved clinical outcomes. The purpose was to verify the accuracy of methods for evaluating tunnel positioning, one of which is the use of postoperative radiographs, in determining the femoral tunnel position following MPFL reconstruction and to compare the variability of tunnel positions to the intraoperatively documented positions on a true-lateral view. METHODS: Seventy-three consecutive MPFL reconstructions were prospectively enrolled. Femoral tunnel positions were intraoperatively determined using fluoroscopy to obtain true-lateral radiographs. Postoperatively, lateral radiographic images were taken. Seven independent radiologists and seven independent orthopaedic knee surgeons evaluated the femoral tunnel position and amount of malrotation for each radiograph. Deviations from the Schoettle's point were measured and repeated after 4 weeks. Intraobserver and interobserver analyses of variance were calculated to determine the reliability of measurements on both intraoperative and postoperative radiographs. RESULTS: Fifty-six patients were included in the final analysis. Tunnel positions were unable to be identified on postoperative radiographs in 14% of cases on average, independent of the degree of radiograph rotation. Intraoperative images showed mean deviations from the tunnel position to the centre of Schoettle's point of 1.9 ± 1.4 mm and 1.6 ± 1.0 mm in anterior-posterior and proximal-distal direction, respectively. Postoperative radiographs showed mean anterior-posterior and deviations of 7.4 ± 4.4 mm and 8.9 ± 5.8 mm assessed by orthopaedic surgeons and 10.6 ± 6.3 mm and 11.6 ± 7.1 mm assessed by radiologists at first and repeated measurement, respectively. The mean proximal-distal deviations were 4.8 ± 4.4 mm and 6.5 ± 6.0 mm and 7.2 ± 6.3 mm and 8.1 ± 7.1 mm, respectively. Measurement of tunnel position on intraoperative fluoroscopic images was significantly different compared to postoperative radiographs for each of the 14 observers (p < 0.05). Significant intraobserver and interobserver differences between the first and repeat measurements for both orthopaedic surgeons and radiologists were observed (p < 0.05). CONCLUSION: Measurement of the femoral tunnel position on postoperative lateral radiographs is not an accurate or reliable method for evaluating tunnel position after MPFL reconstruction due to exposure, contrast, and malrotation of the radiograph from a true-lateral image. In contrast, intraoperative fluoroscopic control allows for a precise lateral view and correct tunnel positioning. Thus, postoperative radiographic images may be unnecessary for the evaluation of femoral tunnel positions, particularly when intraoperative fluoroscopy has been used. STUDY DESIGN: Level II, prospective cohort study.

Increased medial and lateral tibial posterior slopes are independent risk factors for graft failure following ACL reconstruction.

PURPOSE: To analyze the contribution of increased lateral (LTPS) and medial tibial slopes (MTPS) as independent risk factors of graft failure following anterior cruciate ligament (ACL) reconstruction. MATERIALS AND METHODS: Fifty-seven patients with graft failure after ACL reconstruction who underwent revision surgery between 2009 and 2014 were enrolled and matched to a control group of 69 patients with primary anatomic successful ACL reconstruction. Patients were matched based on age, sex, date of primary surgery and graft type. LTPS and MTPS were measured on MRI in a blinded fashion. Tibial and femoral tunnel positions were determined on CT scans. Independent t test was used to compare the MTPS and LTPS between subgroups. Risks of graft failure associated with an increasing MTPS and LTPS were analyzed using binary logistic analysis. RESULTS: The means of LTPS (7.3°) and MTPS (6.7°) in the graft failure group were found to be significantly greater than in the control group (4.6° and 4.1°, respectively; p = < 0.001). Non-anatomic and anatomic tunnel positions were found in 42 cases (73.7%) and 15 cases (26.3%), respectively. There were no significant differences in MTPS or LTPS between patients with anatomic and non-anatomic tunnel positions within the graft failure group. An increase of the MTPS of 1° was associated with an 1.24 times increased likelihood of exhibiting graft failure [95% CI 1.07-1.43] (p = 0.003) and an increase of the LTPS of 1° was associated with an 1.17 times increased likelihood of exhibiting graft failure [95% CI 1.04-1.31] (p = 0.009). The increased risk was most evident in patients with a lateral tibial posterior slope of ≥ 10°. CONCLUSIONS: Increased LTPS and MTPS are independent risk factors for graft failure following ACL reconstruction regardless whether tunnel position is anatomic or non-anatomic. This information may be helpful to clinicians when considering slope correction in selected revision ACL reconstruction procedures.

Differences between traumatic and non-traumatic causes of ACL revision surgery.

PURPOSE: The purpose of this study was to evaluate and classify causes for anterior cruciate ligament (ACL) reconstruction failure. It was hypothesized that specific technical and biological reconstruction aspects would differ when comparing traumatic and non-traumatic ACL reconstruction failures. MATERIALS AND METHODS: One hundred and forty-seven consecutive patients who experienced ACL reconstruction failure and underwent revision between 2009 and 2014 were analyzed. Based on a systematic failure analysis, including evaluation of technical information on primary ACL reconstruction and radiological assessment of tunnel positions, causes were classified into traumatic and non-traumatic mechanisms of failure; non-traumatic mechanisms were further sub-divided into technical and biologic causes. Spearman's rank correlation coefficient and chi-squared tests were performed to determine differences between groups based on various factors including graft choice, fixation technique, technique of femoral tunnel positioning, tunnel malpositioning, and time to revision. RESULTS: Non-traumatic, i.e., technical, and traumatic mechanisms of ACL reconstruction failure were found in 64.5 and 29.1% of patients, respectively. Biological failure was found only in 6.4% of patients. Non-anatomical femoral tunnel positioning was found the most common cause (83.1%) for technical reconstruction failure followed by non-anatomical tibial tunnel positioning (45.1%). There were strong correlations between non-traumatic technical failure and femoral tunnel malpositioning, transtibial femoral tunnel drilling techniques, femoral transfixation techniques as well as earlier graft failure (p < 0.05). CONCLUSIONS: Technical causes, particularly tunnel malpositioning, were significantly correlated with increased incidence of non-traumatic ACL reconstruction failure. Transtibial femoral tunnel positioning techniques and femoral transfixation techniques, showed an increased incidence of non-traumatic, earlier graft failure.

Fluoroscopic control allows for precise tunnel positioning in MPFL reconstruction.

PURPOSE: In MPFL reconstruction, anatomical graft positioning is required to restore physiological joint biomechanics and patellofemoral stability. Considerable rates of non-anatomical femoral tunnel placement exist. The purpose of this study was to analyse whether intraoperative fluoroscopic control is applicable to reduce variability of femoral tunnel positioning. METHODS: Femoral tunnel positions of 116 consecutive MPFL reconstructions applying intraoperative fluoroscopic images were analysed. Tunnel positions were determined by two independent observers according to Schöttle's radiographic measurement method. Mean positions, standard deviations and ranges were calculated to determine the variability of the tunnel positions. Interclass correlation coefficient (ICC) was calculated. RESULTS: The mean anterior/posterior distances from the anatomical insertion of the MPFL to the centre of the femoral tunnel were 2.34 mm (range 0.0-5.9 mm) and 1.7 mm (range 0.1-7.3 mm, SD 1.3) for proximal/distal deviations; 95.7 % (111/116) of femoral tunnel positions were found to be within the anatomical insertion area defined by Schöttle. Interobserver tunnel position measurements were highly reliable (ICC: depth 0.979; height 0.979). CONCLUSION: The study demonstrates that intraoperative fluoroscopic control is a feasible and effective method that enables to create reproducible and precise anatomical femoral tunnel positions in MPFL reconstruction. Accordingly, the routine use of intraoperative fluoroscopy can be recommended. Furthermore, the results indicate Schöttle's method as a reliable method for intraoperative control and postoperative analysis of femoral tunnel positioning. LEVEL OF EVIDENCE: IV.

High non-anatomic tunnel position rates in ACL reconstruction failure using both transtibial and anteromedial tunnel drilling techniques.

INTRODUCTION: Although it is well known from cadaveric and biomechanical studies that transtibial femoral tunnel (TT) positioning techniques are associated with non-anatomic tunnel positions, controversial data exist as so far no clinical differences could have been found, comparing transtibial with anteromedial techniques (AM). The purpose of the study was to analyze if graft failure following TT ACL reconstruction was more commonly associated with non-anatomic tunnel position in comparison with the AM technique. We hypothesized that, compared to AM techniques, non-anatomic tunnel positions correlate with TT tunnel positioning techniques. MATERIALS AND METHODS: A total of 147 cases of ACL revision surgery were analyzed retrospectively. Primary ACL reconstructions were analyzed regarding the femoral tunnel drilling technique. Femoral and tibial tunnel positions were determined on CT scans using validated radiographic measurement methods. Correlation analysis was performed to determine differences between TT and AM techniques. RESULTS: A total of 101 cases were included, of whom 64 (63.4%) underwent the TT technique and 37 (36.6%) the AM technique for primary ACL reconstruction. Non-anatomic femoral tunnel positions were found in 77.2% and non-anatomical tibial tunnel positions in 40.1%. No correlations were found comparing tunnel positions in TT and AM techniques, revealing non-anatomic femoral tunnel positions in 79.7 and 73% and non-anatomic tibial tunnel positions in 43.7 and 35.1%, respectively (p > 0.05). CONCLUSIONS: Considerable rates of non-anatomic femoral and tibial tunnel positions were found in ACL revisions with both transtibial and anteromedial femoral drilling techniques. Despite the potential of placing tunnels more anatomically using an additional AM portal, this technique does not ensure anatomic tunnel positioning. Consequently, the data highlight the importance of anatomic tunnel positioning in primary ACL reconstruction, regardless of the applied drilling technique.

Moderate value of non-contrast magnetic resonance imaging after non-dislocating shoulder trauma.

PURPOSE: The purpose of the present study was to determine the value of shoulder magnetic resonance imaging (MRI) obtained in the community setting interpreted by musculoskeletal radiologists in patients with shoulder pain initiated by a single non-dislocating shoulder trauma. METHODS: In 56 of 61 consecutive patients who underwent shoulder arthroscopy due to pain after a single non-dislocating shoulder trauma, the data sets of non-contrast MRI were complete. These were retrospectively interpreted by three radiologists specialized on musculoskeletal MRI who were blinded for patients' history and who did not have access to the reports of arthroscopy. Standard evaluation forms were used to assess the MRIs for superior labrum anterior and posterior (SLAP) lesions, anterior or posterior labrum lesions, lesions of the long head of biceps tendon (LHB) and for partial tears of the supraspinatus tendon and the upper quarter of the subscapularis tendon. Quality of the MRI was assessed by each radiologist on a four-point scale. RESULTS: The pooled sensitivity for the three radiologists for the detection of SLAP lesions was 45.0 %, for anterior or posterior labrum tears 77.8 and 66.7 %, for lesions of the LHB 63.2 % and for partial tears of the supraspinatus or subscapularis tendon tears 84.8 and 33.3 %. Corresponding inter-rater reliabilities were poor (SLAP lesions) to substantial (anterior labrum tears). Quality of MRI only influenced the accuracy for the detection of posterior labrum tears. CONCLUSION: A non-contrast shoulder MRI obtained in the community setting after non-dislocating shoulder trauma has a moderate sensitivity for most intraarticular pathologies when interpreted by musculoskeletal radiologists. Accuracy is dependent on the observer and not on the assessed quality. LEVEL OF EVIDENCE: Case series, Level IV.

Management of shoulder instability: the current state of treatment among German orthopaedic surgeons.

INTRODUCTION: The aim of this study was to evaluate the current state of treatment in traumatic anterior shoulder dislocation in Germany and to detect changes over the last 12 years. METHODS: Seven hundred ninety-six trauma and/or orthopaedic departments were found in the German hospital directory 2012. The websites of each department were searched for the email address of the responsible shoulder surgeon (if applicable) or the head of the department. Seven hundred forty-six email addresses were found, and emails with the request to participate in an online survey were sent in January 2013. Six hundred seventy-five emails probably reached the correct addressee. Seventy-one emails were rejected, and no contact could be made. One-hundred ninety-one (28 %) participated in the study. The data were compared to similar data from a survey on shoulder dislocation performed in the same department and published in 2001. RESULTS: After the first-time traumatic shoulder dislocation in patients aged younger than 30 years participating in sports, 14 % of the participants would prefer conservative treatment, 83 % arthroscopic, and 3 % open surgery. When surgery was indicated, arthroscopic Bankart repair was the treatment of choice for 93 % of the participants. In 2001, 27 % had indicated conservative treatment after the first-time shoulder dislocation in active patients younger than 30 years. When surgery was indicated, 66 % had performed arthroscopic and 34 % open stabilization. For the standard arthroscopic Bankart repair without concomitant injuries, 41 % of the participants use two and 54 % three suture anchors. Knotless anchors were preferred by 72 %. In the case of glenoid bone loss greater than 25 %, only 46 % perform a procedure for glenoid bone augmentation. Fifteen percent of the participants always recommended immobilization in external rotation after traumatic first-time shoulder dislocation. CONCLUSIONS: The majority of participants recommend arthroscopic Bankart repair with two or three suture anchors in young persons with the first-time dislocations. Compared to 2001 less recommend conservative treatment, complex "open" surgical procedures are no longer used. The knowledge that a Bankart procedure likely fails in significant glenoid bone loss is not implemented in the clinical practice. Thus, there is a need to educate surgeons on this topic.

Current status of ACL reconstruction in Germany.

INTRODUCTION: Reconstruction of the anterior cruciate ligament (ACL) is characterized by a variety of possibilities concerning its implementation. Different choices for grafts, fixation methods and tunnel positioning, as well as diverse technical tools are available and have clinical significance. Besides specific pre- and post-operative procedures, different indications for surgery and further surgeon-/clinic-related factors add variability to the treatment. In response to the lack of descriptive statistics about the implementation of these factors and the increasing numbers of ACL reconstructions this study has been conducted to display the current state of the treatment for ACL tears throughout Germany. MATERIALS AND METHODS: 709 clinics with surgical and orthopedic departments were provided an online-questionnaire that surveyed their statistical records (e.g. annually implemented operations, number of surgeons, duration of operations), implemented techniques (e.g. choice of grafts, construction of drilling tunnel, tibial/femoral fixation) and personal assessment (e.g. frequency/cause of graft failure, frequency/handling of infection). The response rate was 22 % (n = 155). Based on the statistical records a specialized group within the respondents was identified, enabling a cross-comparison between high- and low-volume surgeons. RESULTS: On average, the German orthopedic surgeons in the clinics surveyed annually performs 35 ACL reconstructions, with each operation lasting an average of 67 min. After subdividing the data with references to annually performed surgeries into high- and low-volume-surgeons, differences and common features between the subgroups become apparent. Differences between high- and low-volume-surgeons, respectively, show shorter duration of both ACL reconstructions (55 vs. 71 min) and revision ACL reconstructions (75 vs. 90 min), higher membership rates in professional associations (83 vs. 38 % have at least one membership), more frequent implementation of stability examinations (47 vs. 21 %) and different frequencies of femoral drilling techniques (using the anterolateral portal in 71 vs. 54 %). With reference to evaluating operation dates, choosing grafts and assessing reasons for graft failure both groups share commonalities, as well as regarding the predominant use of monofixation for femoral fixation (88 % of the participants-mainly with endobutton in 38 % and transfixation pin in 27 %) and for tibial fixation (81 % of the participants-mainly with bioabsorbable screw in 60 %). CONCLUSIONS: The treatment of ACL tears in the group of German clinics studied is characterized by a variety of surgical possibilities. This condition might reflect the entirety of clinics reconstructing ACL in Germany. For the first time, a descriptive statistical survey was implemented to display this variety and to provide insight into the current status quo. Within the entirety of surgeons implementing ACL reconstruction a specialized subgroup with a particular expertise seems to exist.

Rolimeter measurements are suitable as substitutes to stress radiographs in the evaluation of posterior knee laxity.

PURPOSE: The quantification of posterior knee laxity is crucial in the evaluation of injuries to the posterior cruciate ligament (PCL) as it has important implications to the treatment for these injuries. The objective of this study was to compare the test results of stress radiography and instrumented drawer testing (Rolimeter) for the assessment of posterior knee laxity in patients with PCL injury. METHODS: In 45 patients with an injury to the PCL, lateral radiographs of both knees were obtained under anterior and posterior tibial load (150 N) using a standardized approach. Patients with injury of the ACL to either knee were excluded from the study. During the same clinic visit, an instrumented measurement of anterior-posterior knee laxity was performed at 90° of knee flexion by an experienced examiner using the Rolimeter device. The mean side-to-side differences (SSD) of both (radiographic and instrumented) measurements were compared to each other, and the correlation was calculated using the Pearson coefficient. RESULTS: The SSD (affected/healthy side) of posterior translation determined from the radiographs was 8.2 ± 3.2 mm, and the SSD of the instrumented measurement testing was 7.6 ± 3.2 mm. The mean difference between radiographic and Rolimeter test results was 1.8 ± 1.5 mm. The Pearson's correlation coefficient revealed a good correlation between both measurements of 0.74. CONCLUSIONS: It may be suggested by the results of this study that under the absence of an ACL injury and a fixed posterior drawer sign, the Rolimeter is a suitable tool to assess the posterior laxity of the knee in the clinical setting. Its advantages are the absence of radiation to the patient, its availability, and the low cost. Therefore, the Rolimeter device may serve as a valuable alternative to stress radiography in the evaluation of PCL-injured patients. LEVEL OF EVIDENCE: II.

Variability of landmark acquisition affects tunnel calculation in image-free ACL navigation.

PURPOSE: The purpose of this study was to determine the inter- and intraobserver variability of intraarticular landmark identification for tunnel position calculation in image-free anterior cruciate ligament (ACL) navigation. METHODS: In a test/retest scenario, thirteen experienced ACL surgeons (>50 reconstructions year) experienced in image-free ACL navigation were asked to identify the landmarks required for image-free ACL navigation in the same cadaver knee. Landmark positions were registered using a fluoroscopic ACL navigation system. Positions were determined using validated radiological measurement methods. For variability analysis, mean positions, deviations between the test/retest positions, standard deviations (SD) and range were calculated. RESULTS: Interobserver analysis showed a mean variability (SD) for the tibial landmark positions of 3.0 mm with deviations of up to 24.3 mm (range). Mean femoral landmark variability was 2.9 mm (SD) with deviations of up to 11.3 mm (range). Intraobserver analysis showed a tibial reproducibility of 2.2 mm (SD 2.0 mm; range 10.9 mm) and a femoral of 1.9 mm (SD 1.9 mm; range 10.4 mm). CONCLUSION: The data of the presented study suggest that a considerable inter- and intraobserver variability in intraarticular landmark identification exists. Reasonable ranges were found that have to be considered as a potential risk for miscalculation of tunnel positions in image-free ACL reconstruction. CLINICAL RELEVANCE: Landmark acquisition affects tunnel calculation in image-free ACL. LEVEL OF EVIDENCE: IV.

Current state of treatment of acute acromioclavicular joint injuries in Germany: is there a difference between specialists and non-specialists? A survey of German trauma and orthopaedic departments.

PURPOSE: The purpose of this study was to evaluate currently preferred treatment strategies as well as the acceptance of new arthroscopic techniques among German orthopaedic surgeons. We assumed that surgeons specialized in shoulder surgery and arthroscopy would treat acute acromioclavicular joint dislocations different to non-specialized surgeons. METHODS: Seven hundred and ninety-six orthopaedic and/or trauma departments were found through the German hospital directory of 2012. Corresponding websites were searched for the email address of the chair of shoulder surgery (if applicable) or the department. Seven hundred forty-six emails with the request for study participation including a link to an online survey of 36 questions were sent. In 60 emails, the recipient was unknown. RESULTS: Two hundred and three (30 %) surgeons participated in the survey. one hundred and one were members of the AGA (German-speaking Society for Arthroscopy and Joint-Surgery) and/or of the DVSE (German Association of Shoulder and Elbow Surgery) and regarded as specialists, while 102 were non-members and regarded as non-specialists. According to the treatment of Rockwood I/II and IV-VI injuries, no significant differences were found. Seventy-four % of non-specialists and 67 % of specialists preferred surgical treatment for Rockwood III injuries (P = 0.046). Non-specialists would use the hook plate in 56 % followed by the TightRope in 16 %; specialists would use the TightRope in 38 % followed by the hook plate in 32 % (P = 0.004). CONCLUSIONS: The majority of German orthopaedic and trauma surgeons advise surgical treatment for Rockwood III injuries. Specialists recommend surgery less often. Non-specialists prefer the hook plate, whereas specialists prefer the arthroscopic TightRope technique. LEVEL OF EVIDENCE: Observational survey, Level IV.

Soft tissue injury of the shoulder after single non-dislocating trauma: prevalence and spectrum of intraoperative findings during shoulder arthroscopy and treatment results.

BACKGROUND AND PURPOSE: The purpose of our study was to present the spectrum and prevalence of intraarticular lesions in patients with shoulder pain after a single non-dislocating shoulder trauma and to evaluate the clinical results according to pathology and workers' compensation status. METHODS: Sixty consecutive patients (61 shoulders) with shoulder pain following a single non-dislocating shoulder trauma had shoulder arthroscopy. The indication for surgery was either persistent pain for 3 months or longer after trauma and/or an intraarticular lesion on MRI. Patients with history of shoulder complaints, previous shoulder surgery, a complete rotator cuff tear or a fracture of the shoulder girdle were excluded. Intraarticular findings during shoulder arthroscopy were retrospectively analyzed. After a minimum follow-up of 1 year patients were contacted by telephone interview and ASES score, Simple Shoulder Test, Subjective Shoulder Value and residual pain were assessed for the entire population and for patients with and without workers' compensation. RESULTS: The most common intraarticular findings were SLAP (44.3 %) and Pulley (19.7 %) lesions followed by lesions of the anterior or posterior labrum (14.8 %). The mean age of the 13 women and 47 men was 41.9 years (SD 10.9). Patients with workers' compensation had significantly lower scores than patients without and had a significantly lower return to work rate than patients without. INTERPRETATION: In patients with persistent shoulder pain after sprain or contusion arthroscopy revealed a broad spectrum of intraarticular findings. Patients with workers' compensation claims had worse results than those without. LEVEL OF EVIDENCE: Case series (Level IV).

The fabella syndrome - a rare cause of posterolateral knee pain: a review of the literature and two case reports.

BACKGROUND: The purpose of this article was to evaluate the risks and benefits of non-operative treatment versus surgical excision of a fabella causing posterolateral knee pain. We performed a systematic review of literature and also present two case reports.Twelve publications were found in a PubMed literature review searching the word "fabella syndrome". Non-operative treatment and surgical excision of the fabella has been described. CASE PRESENTATION: Two patients presented to our outpatient clinic with persisting posterolateral knee pain. In both cases the presence of a fabella was identified, located in close proximity to the posterolateral femoral condyle. All other common causes of intra- and extra articular pathologies possibly causing the posterolateral knee pain were excluded.Following failure to respond to physiotherapy both patients underwent arthroscopy which excluded other possible causes for posterolateral knee pain. The decision was made to undertake surgical excision of the fabella in both cases without complication.Both patients were examined 6 month and one year after surgery with the Tegner activity score, the Visual Analogue Scale (VAS), and International Knee Documentation Committee Score (IKDC). CONCLUSION: Consistent posterolateral pain during exercise might indicate the presence of a fabella syndrome. Resecting the fabella can be indicated and is a minor surgical procedure with minimal risk. Despite good results in the literature posterolateral knee pain can persist and prevent return to a high level of sports. LEVEL OF EVIDENCE: IV, case reports and analysis of literature.

Low inter- and intraobserver variability allows for reliable tunnel measurement in ACL reconstruction using the quadrant method.

INTRODUCTION: Correct anatomic tunnel positions are essential in anterior cruciate ligament (ACL) reconstruction. To establish recommendations for tunnel positioning based on anatomical findings and to compare tunnel positions with clinical results, different radiological measurement methods as the quadrant method exist. Comparing the data of different observers requires the validation of the reliability of measurement methods. The purpose of this study therefore was to determine the reliability of the quadrant method to measure tunnel positions in ACL reconstruction. The hypothesis was, that the quadrant method shows a low inter- and intraobserver variability. MATERIALS AND METHODS: In a test/retest scenario 20 knee surgeons were asked to determine defined tunnel positions in five lateral radiographs applying the quadrant method. Rotation, angle deviation, height and depth of the quadrant as well as absolute and relative tunnel positions of each observation were measured along referenced scales. Mean sizes and angle deviations of the quadrants, tunnel positions and deviations between the test/retest positions were calculated as well as standard deviations and range. RESULTS: Interobserver variability analyses, to plan as well as to determine tunnel positions in ACL reconstruction, showed a mean variability (SD) of <1 mm, with ranges of 2.5 mm for planning and 3.7 mm for determination of tunnel positions using the quadrant method. Intraobserver analysis showed mean variability with deviations of <1 mm and maximum standard deviations of 0.7 mm and ranges of up to 2.3 mm. CONCLUSIONS: We confirmed the hypothesis that the quadrant method has a low inter- and intraobserver variability. Based on the presented validation data, the quadrant method can be recommended as reliable method to radiographically describe insertion areas of the ACL as well as to determine tunnel positions in ACL reconstruction intra and postoperatively.