Hand Dominance Is Not of Significance in Performing Fundamental Arthroscopic Skills Simulation Training Tasks.

Purpose: To compare the performance of the dominant and nondominant hand during fundamental arthroscopic simulator training. Methods: Surgical trainees who participated in a 2-day simulator training course between 2021 and 2023 were classified, according to their arthroscopic experience in beginners and competents. Only right-handed individuals with complete data sets were included in the study. Ambidexterity was trained using a box trainer (Fundamentals of Arthroscopic Surgery Training, Virtamed AG, Schlieren, Switzerland).Two tasks, periscoping for learning camera guidance and triangulation for additional instrument handling, were performed 4 times with the camera in the dominant hand and then in the nondominant hand. For each task, exercise time, camera path length, and instrument path length were recorded and analyzed. Results: Out of 94 participants 74 right-handed individuals (22 females, 52 males) were classified to novices (n = 43, less than 10 independently performed arthroscopies) and competents (n = 31, more than 10 independently performed arthroscopies). Competents performed significantly better than novices. No significant difference was found after changing the guiding hand for the camera from the dominant to the nondominant hand regarding the camera path length and the instrument path length. Notably, tasks were performed even faster when using the camera in the nondominant hand. Conclusions: Our data demonstrate that the learned manual skills during basic arthroscopic training are quickly transferred to the contralateral side. In consequence, additional fundamental skills training for camera guidance and instrument handling of the nondominant hand are not necessary. Clinical Relevance: For skillful arthroscopy, camera guidance and instrument handing must be equally mastered with both hands. It is important to understand how hand dominance may affect learning during arthroscopic simulator training.

The number of arthroscopies performed by trainees does not deduce the level of their arthroscopic proficiency.

PURPOSE: It is reasonable to question whether the case volume is a suitable proxy for the manual competence of an arthroscopic surgeon. The aim of this study was to evaluate the correlation between the number of arthroscopies previously performed and the arthroscopic skills acquired using a standardized simulator test. METHODS: A total of 97 resident and early orthopaedic surgeons who participated in arthroscopic simulator training courses were divided into five groups based on their self-reported number of arthroscopic surgeries: (1) none, (2) < 10, (3) 10 to 19, (4) 20 to 39 and (5) 40 to 100. Arthroscopic manual skills were evaluated with a simulator by means of the diagnostic arthroscopy skill score (DASS) before and after training. Seventy-five points out of 100 must be achieved to pass the test. RESULTS: In the pretest, only three trainees in group 5 passed the arthroscopic skill test, and all other participants failed. Group 5 (57 ± 17 points; n = 17) scored significantly higher than the other groups (group 1: 30 ± 14, n = 20; group 2: 35 ± 14, n = 24; group 3: 35 ± 18, n = 23; and group 4: 33 ± 17, n = 13). After a two-day simulator training, trainees showed a significant increase in performance. In group 5, participants scored 81 ± 17 points, which was significantly higher than the other groups (group 1: 75 ± 16; group 2: 75 ± 14; group 3: 69 ± 15; and group 4: 73 ± 13). While self-reported arthroscopic procedures were n.s. associated with higher log odds of passing the test (p = 0.423), the points scored in the pretest were found to be a good predictor of whether a trainee would pass the test (p < 0.05). A positive correlation was observed between the points scored in the pretest and the posttest (p < 0.05, r = 0.59, r2 = 0.34). CONCLUSIONS: The number of previously performed arthroscopies is not a reliable indicator of the skills level of orthopaedic residents. A reasonable alternative in the future would be to verify arthroscopic proficiency on the simulator by means of a score as a pass-fail examination. LEVEL OF EVIDENCE: III.

Surgical simulation training should become a mandatory part of orthopaedic education.

PURPOSE: Ethical concerns and increasing economic constraints of hospitals have caused a reduction in proper training and education. It has been hypothesized that due to the lack of a one-to-one apprenticeship throughout the residency, surgical simulation training is essential. METHODS: Between June 2020 and June 2021, residents from teaching hospitals in Switzerland, France, Germany, and Luxembourg were surveyed to learn about their experience with and thoughts on surgical simulation training. Survey responses were analysed using descriptive statistics. RESULTS: Of the 596 residents surveyed, 557 residents (51% female, 49% male) from Switzerland (270), France (214), Germany (52) and Luxembourg (21) agreed to anonymous data analysis. Among those giving consent, 100% considered that simulation training was important for their practical education and 84% thought that simulation training should become a mandatory part of their curriculum, with an average estimated training time of 42 ± 51 h per year, based on the survey. CONCLUSIONS: This study suggests that surgical simulation training is well accepted and even demanded among surgical residents as an alternative training solution able to address some of the limitations and challenges of the current one-to-one apprenticeship model. There is a wide variation among the residents regarding the number of training hours required, underscoring the need for structured performance-based simulator training.

The Diagnostic Arthroscopy Skill Score (DASS): a reliable and suitable assessment tool for arthroscopic skill training.

PURPOSE: To develop and validate a novel score to more objectively assess the performance of diagnostic knee arthroscopy using a simulator. METHODS: A Diagnostic Arthroscopy Skill Score (DASS) was developed by ten AGA (AGA-Society for Arthroscopy and Joint-Surgery) instructors for the assessment of arthroscopic skills. DASS consists of two parts: the evaluation of standardized diagnostic knee arthroscopy (DASSpart1) and the evaluation of manual dexterity, including ambidexterity and triangulation, using objective measurement parameters (DASSpart2). Content validity was determined by the Delphi method. One hundred and eleven videos of diagnostic knee arthroscopies were recorded during simulator training courses and evaluated by six specially trained instructors using DASS. Construct validity, measurement error calculated by the minimum detectable change (MDC), internal consistency using Cronbach's alpha and interrater and intrarater reliability were assessed. The Bland-Altman method was used to calculate the intrarater agreement. RESULTS: Six skill domains were identified and evaluated for each knee compartment. DASS, DASSpart1, and DASSpart2 showed construct validity, with experts achieving significantly higher scores than competents and novices. MDC was 4.5 ± 1.7 points for DASSpart1. There was high internal consistency for all domains in each compartment from 0.78 to 0.86. The interrater reliability showed high agreement between the six raters (ICC = 0.94). The evaluation of intrarater reliability demonstrated good and excellent agreement for five raters (ICC > 0.80) and moderate agreement for one rater (ICC = 0.68). The Bland-Altman comparison showed no difference between the first and second evaluations in five out of six raters. Precision, estimated by the regression analysis and comparison with the method of Bland and Altman, was excellent for four raters and moderate for two raters. CONCLUSIONS: The results of this study indicate good validity and reliability of DASS for the assessment of the surgical performance of diagnostic knee arthroscopy during simulator training. Standardized training is recommended before arthroscopy surgery is considered in patients. LEVEL OF EVIDENCE: II.

Ten hours of simulator training in arthroscopy are insufficient to reach the target level based on the Diagnostic Arthroscopic Skill Score.

PURPOSE: Simulator arthroscopy training has gained popularity in recent years. However, it remains unclear what level of competency surgeons may achieve in what time frame using virtual training. It was hypothesized that 10 h of training would be sufficient to reach the target level defined by experts based on the Diagnostic Arthroscopic Skill Score (DASS). METHODS: The training concept was developed by ten instructors affiliated with the German-speaking Society of Arthroscopy and Joint Surgery (AGA). The programme teaches the basics of performing arthroscopy; the main focus is on learning and practicing manual skills using a simulator. The training was based on a structured programme of exercises designed to help users reach defined learning goals. Initially, camera posture, horizon adjustment and control of the direction of view were taught in a virtual room. Based on these skills, further training was performed with a knee model. The learning progress was assessed by quantifying the exercise time, camera path length and instrument path length for selected tasks. At the end of the course, the learners' performance in diagnostic arthroscopy was evaluated using DASS. Participants were classified as novice or competent based on the number of arthroscopies performed prior to the assessment. RESULTS: Except for one surgeon, 131 orthopaedic residents and surgeons (29 women, 102 men) who participated in the seven courses agreed to anonymous data analysis. Fifty-eight of them were competents with more than ten independently performed arthroscopies, and 73 were novices, with fewer than ten independently performed arthroscopies. There were significant reductions in exercise time, camera path length and instrument path length for all participants after the training, indicating a rapid increase in performance. No difference in camera handling between the dominant and non-dominant sides was found in either group. The competents performed better than the novices in various tasks and achieved significantly better DASS values on the final performance test. CONCLUSIONS: Our data have demonstrated that arthroscopic skills can be taught effectively on a simulator, but a 10-h course is not sufficient to reach the target level set by experienced arthroscopists. However, learning progress can be monitored more objectively during simulator training than in the operating room, and simulation may partially replace the current practice of arthroscopic training. LEVEL OF EVIDENCE: III.

[Virtual arthroscopy : Gaming or training concept of the future]. / Virtuelle Arthroskopie : Computerspiel oder Weiterbildungskonzept der Zukunft?

Arthroscopy is a technically challenging surgical procedure with a relatively shallow learning curve compared to open procedures. To become an expert special cognitive and manual abilities have to be acquired and trained. The current situation in further medical education combined with the increasing economic pressure in the medical field does not leave enough room for a time-consuming training in arthroscopic techniques. A structured simulation training could be an alternative solution to this problem. The benefits of arthroscopic simulation training are meanwhile well documented. The complex tasks that an expert carries out during arthroscopy can be fragmented into more simple and elementary exercises and can be trained in a stress-free environment outside the operation room. An essential advantage of simulation training is the assessment of objective measurement parameters during the individual exercises. These parameters can be used to evaluate the learning process and performance of arthroscopic tasks. The aim of this review is to reflect the current state of simulation technology in arthroscopy and to show how simulator training can be meaningfully and effectively integrated into arthroscopic further training, exemplified by a modern medical further education concept.

Meniscectomy leads to early changes in the mineralization distribution of subchondral bone plate.

PURPOSE: It is generally recognized that the subchondral bone plate (SBP) is involved in development of osteoarthritis (OA). However, the pathophysiological significance is not yet clear. The goal of this study is to investigate the extent of the changes that occur in SBP of the tibial plateau in the early stages of experimental OA. METHODS: Forty-three female rabbits were assigned to 5 experimental (n = 8 each group) and one sham group (n = 3). OA was induced by medial meniscectomy in the right knee, the left knee served as control. 2, 4, 8, 12, and 24 weeks after meniscectomy, cartilage damage was evaluated, and bone mineral density (BMD) and mineralization distribution of the SBP was measured by computed tomography osteoabsorptiometry (CT-OAM). RESULTS: Cartilage damage started 2 weeks after meniscectomy with surface roughening. Cartilage defects increased over time. 24 weeks postoperatively, subchondral bone was exposed. As early as 2 weeks after meniscectomy, BMD in the medial tibial plateau decreased significantly. BMD increased again and reached the values of the non-operated knee 12 weeks postoperatively. In addition, already 4 weeks after meniscectomy a significant shift of the density maximum on the medial tibial plateau, which is normally centrally located toward the margin was observed. CONCLUSIONS: In conclusion, the results of this study contribute to the concept of early involvement of the SBP in the development of OA. The hypothesis that changes in the SBP occur simultaneously to cartilage damage was confirmed.

Evidence of an autoregulatory mechanism of regional bone blood flow at hypotension.

BACKGROUND: Blood flow in various organs is determined by an autoregulatory mechanism that guarantees constant organ perfusion over a wide range of arterial blood pressure changes. This physiological principle has been proven for the kidney, brain and intestinal tract, but so far not for bone. This study was carried out to determine whether there is an autoregulatory mechanism of bone or not. METHODS: The fluorescent microsphere reference sample method was used to determine blood flow within the bone and kidneys. Eight anesthetized female New Zealand rabbits received left ventricular injections of fluorescent microspheres over a wide range of arterial pressure levels prior to removal of kidney, femur and tibia. Blood flow values were calculated by measurement of fluorescence intensity in kidney and bone and correlated to fluorescence intensity in the peripheral blood (reference sample). RESULTS: Despite a reduction of mean arterial pressure from 100 to 80 mmHg bone blood flow remained constant. Further reduction of mean arterial pressure results in a linear decrease in bone blood flow. CONCLUSION: The correlation between arterial pressure and organ perfusion in the bone is similar to blood flow within the kidney, indicating the presence of an autoregulated blood flow mechanism within the bone tissue.

Local cooling reduces regional bone blood flow.

Local cooling is very common after bone and joint surgery. Therefore the knowledge of bone blood flow during local cooling is of substantial interest. Previous studies revealed that hypothermia leads to vasoconstriction followed by decreased blood flow levels. The aim of this study was to characterize if local cooling is capable of inducing reduced blood flow in bone tissue using a stepwise-reduced temperature protocol in experimental rabbits. To examine bone blood flow we utilized the fluorescent microsphere (FM) method. In New Zealand white rabbits one randomly chosen hind limb was cooled stepwise from 32 to 2°C, whereas the contra lateral hind limb served as control. Injection of microspheres was performed after stabilization of bone and muscle temperature at each temperature level. Bones were removed, dissected and fluorescence intensity was determined to calculate blood flow values. We found that blood flow of all cooled regions decreased relative to the applied external temperature. At maximum cooling blood flow was almost completely disrupted, indicating local cooling as powerful regulatory mechanism for regional bone blood flow (RBBF). Postoperative cooling therefore may lead to strongly decreased bone blood flow values. As a result external cooling has capacity to both diminish bone healing and reduce bleeding complications.

[Double-bundle technique - anatomic reconstruction of the anterior cruciate ligament]. / Die Zwei-Bündel-Technik - eine anatomische Rekonstruktion des vorderen Kreuzbandes.

OBJECTIVE: To improve the rotational stability of the knee by anatomic reconstruction of the anterior cruciate ligament by socalled double-bundle technique using anteromedial and posterolateral grafts from native semitendinosus and gracilis. The grafts are fixed with bioabsorbable screws utilizing aperture fixation. INDICATIONS: Complete tear of the anterior cruciate ligament with positive Lachman sign and pivot shift. CONTRAINDICATIONS: Open growth plate. Osteoarthritis > grade 1 according to Jäger & Wirth. Age > or = 50 years with low sports activity (relative contraindication). SURGICAL TECHNIQUE: Graft harvest of the semitendinosus and gracilis tendons via a 3-cm horizontal skin incision parallel to pes anserinus and preparation of the tendons as double-looped grafts. Arthroscopy, resection of the stump of the anterior cruciate ligament, and clearance of its origin and insertion. Tunnel placement by means of aiming devices in the following order: tibial posterolateral, tibial anteromedial, femoral anteromedial (transtibial or via the anteromedial portal in 120 degrees flexion), and femoral posterolateral (via additional medial arthroscopic portal). The anteromedial (semitendinosus tendon) and posterolateral (gracilis tendon) bundles are passed through the tunnels and fixed on the femoral side. Tibial fixation of the graft by bioresorbable interference screw with knee flexion of 45 degrees (anteromedial) and 10 degrees (posterolateral). POSTOPERATIVE MANAGEMENT: Depending on the degree of swelling, rehabilitation with partial weight bearing for 14 days and full range of motion. Return to sports after 6 months, no contact sports until 9 months. RESULTS: From May 2004 to June 2005, anatomic double-bundle reconstruction was performed in 19 patients (13 male, six female, average age 31 years [18-48 years]) with isolated anterior cruciate ligament rupture without concomitant lesions. Clinical follow-up examination on average at 21.3 months (16-30 months) postoperatively. The Lysholm Score improved from an average of 65.2 to 94.5 points (75-100 points). The IKDC (International Knee Documentation Committee) Score yielded nine very good and ten good results in the relevant subgroups of motion, effusion and ligament stability. Measurement of anteroposterior translation with the KT-1000 instrument at 134 N showed increased translation of 1.8 mm (-2 to 5 mm) compared to the contralateral knee.

Anterior shoulder instability modifies glenoid subchondral bone density.

Subchondral bone mineralization is used as a morphologic marker for individual stress distribution of joints and therefore may help to distinguish variations of glenohumeral contact. Therefore, an in vivo analysis was done to evaluate glenoid stress distribution in anterior glenohumeral instability by computed tomography osteoabsorptiometry. Patients with recurrent anterior glenohumeral dislocation, seven of posttraumatic and six of atraumatic origin, and an intact rotator cuff were grouped retrospectively and compared with healthy, age-matched shoulder specimens from cadavers (n = 13). Glenoid subchondral bone mineralization, including those in all patients with anterior glenohumeral instability, indicated a more anterior and inferior stress distribution compared with stable shoulders. The position of the anterior glenoid density maximum had shifted anteriorly and inferiorly whereas the position of the posterior maximum had shifted anteriorly. Analyzing results on the basis of cause, in posttraumatic instabilities, the shift of the anterior maximum mainly was anterior and in atraumatic instabilities, it mainly was inferior. Individual glenoid stress distribution in anterior glenohumeral instability can be assessed objectively by computed tomography osteoabsorptiometry. The shift of the density maxima corresponded with anterior and inferior directions of humeral head displacement, whereas the degree of changes varied according to the cause of glenohumeral instability.

The sublabral foramen: does it affect stress distribution on the anterior glenoid?

Even though it is believed that a sublabral foramen (SF) requires no treatment, no objective data are available to establish whether this condition bears a relationship to anterior-inferior glenohumeral instability. Therefore, the influence on glenoid subchondral bone mineralization of an isolated SF was investigated, because the individual distribution of subchondral bone mineralization may be used as an indirect parameter for long-term stress distribution of joints. Two age- and side-matched groups of healthy glenohumeral specimens with SF (n = 10, aged 37-85 years) and without SF (n = 10, aged 36-86 years) were examined by computed tomography osteoabsorptiometry. As variables for comparison, the anterior and posterior density maxima on the glenoid were measured in a standardized manner. No shift of the anterior density maximum [p(x1) = 0.353/p(y1) = 0.739] was found between both groups, which is in contrast to anterior glenohumeral instability. This indicates a long-term stress distribution in SF shoulders comparable to that in non-SF shoulders. The data suggest that an isolated SF is probably not disproportionately related to glenohumeral instability and support the general assumption that surgical treatment of SF is not required.

The mineralization patterns at the subchondral bone plate of the glenoid cavity in healthy shoulders.

The distribution of mineralization of the subchondral bone plate (DMSB) is used as a parameter for the individual stress distribution of joints. In this study the DMSB of the glenoid from healthy glenohumeral joints was analyzed. In a standardized manner, 44 macroscopically normal shoulder specimens (28 individuals aged 18 to 96 years) were selected and DMSB of the glenoid was evaluated by computed tomography osteoabsorptiometry. The mineralization patterns were described, and the 2 most frequent maxima of density were localized and statistically assessed to analyze any influence of age, side, or shape of the glenoid on DMSB. An anterior-superior maximum was found in 100% and a posterior maximum in 82%. Three different patterns of DMSB were distinguished in relation to the constant anterior-superior maximum: 68% were not combined with a further central or anterior-inferior maximum (type A), whereas a central maximum coexisted in 18% (type B) and an anterior-inferior maximum in 14% (type C). The localization of the anterior-superior and posterior maxima was independent of age or side of the glenoid, indicating a constant long-term stress distribution in healthy glenohumeral joints. The typical localization of the density maxima showed that stress distribution is usually peripherical (82%) and often bicentric. Functional aspects related to internal rotation of the arm support a more constant anterior than posterior stress on the glenoid surface.