Immersive virtual reality in orthopedic surgery as elective subject for medical students : First experiences in curricular teaching.

BACKGROUND: Virtual reality (VR) simulators have been introduced for skills training in various medical disciplines to create an approximately realistic environment without the risk of patient harm and have improved to more immersive VR (iVR) simulators at affordable costs. There is evidence that training on VR simulators improves technical skills but its use in orthopedic training programs and especially in curricular teaching sessions for medical students are currently not well established. The aim of this study was to describe the implementation of a VR operating theater as an elective course for undergraduate medical students and to evaluate its effect on student learning. METHODS: An elective course for 12 students was implemented during the summer semester of 2023. Using Oculus Quest 2 headsets (Reality Labs, Meta Platforms, USA) and controllers and the PrecisionOS platform, they were able to train five different surgical procedures. The courses were accompanied by weekly topic discussions and instructional videos. Students were assigned to two groups: group VR vs. group non-VR. The groups were switched after 5 weeks. User feedback and performance development (theoretical and procedural surgical knowledge) after VR training were assessed using three questionnaires. RESULTS: The students highly appreciated the implementation of VR training into their curriculum and 91% stated that they would opt for further VR training. All students stated that VR training improved their understanding of surgical procedures and that it should be obligatory in surgical training for undergraduate medical students. After 5 weeks of training, students in the VR group achieved significantly better results (100 out of maximum 180 points) than the non-VR group (70 points, p = 0.0495) in procedural surgical knowledge. After completion of the VR training the VR group achieved 106 points and the non-VR group 104 points (p = 0.8564). The procedural knowledge for non-VR group after 5 weeks significantly improved after VR training from 70 to 106 points (p = 0.0087). CONCLUSION: The iVR can be easily integrated into the curriculum of medical students and is highly appreciated by the participants. The iVR statistically improves the procedural knowledge of surgical steps compared to conventional teaching methods. Further implementation of iVR training in curricular teaching of medical students should be considered.

Effect of an upper body exoskeleton for surgeons on postoperative neck, back, and shoulder complaints.

OBJECTIVES: Surgeons are exposed to high levels of physical stress while working in the operating room. In industry, so-called exoskeletons are used to support the back and shoulder area. The aim of this study was to investigate the feasibility and effects of an upper body exoskeleton on postoperative physical complaints of surgeons. METHODS: Surgeons from a university hospital in the fields of orthopedics, trauma, and visceral surgery performed 2 operations of the same type and planned length on 2 different days. The first operation was performed without an exoskeleton, the second with an exoskeleton. The participants completed questionnaires on shoulder pain (Shoulder Pain and Disability Index [SPADI]), neck pain (Visual Analogue Scale [VAS] and Neck Disability Index [NDI]), and back pain (VAS and Oswestry Disability Index [ODI]) before and after the procedure. RESULTS: A total of 25 participants were included and performed 50 surgeries with a mean surgery duration of 144 minutes without and 138 minutes with the exoskeleton. Without the exoskeleton, the activity of the operation resulted in a significant increase of the VAS neck by 1.0 point (SD 1.2; P < .001), NDI by 4.8 (SD 8.6; P = .010), VAS back by 0.7 (SD 1.0; P = .002), and ODI by 2.7 (SD 4.1; P = .003). With the exoskeleton the participants reported significantly fewer complaints after the surgery (VAS neck: P = .001; NDI: P = .003; VAS back: P = .036; ODI: P = .036; SPADI: P = .016). CONCLUSION: An upper body exoskeleton can significantly reduce the discomfort in the neck, shoulder, and back caused to surgeons by surgery.

Comparison of needle and conventional arthroscopy for visualisation of predefined anatomical structures of the knee joint: a feasibility study in human cadavers and patients.

BACKGROUND: In terms of the optics used for Knee arthroscopy, a large number of different endoscopes are currently available. However, the use of the 30° optics in knee arthroscopy has been established as the standard procedure for many years. As early as the 1990s, needle arthroscopy was occasionally used as a diagnostic tool. In addition to the development of conventional optics technology in terms of camera and resolution, needle arthroscopes are now available with chip-on-tip image sensor technology. To date, no study has compared the performance of this kind of needle arthroscopy versus standard arthroscopy in the clinical setting in terms of the visibility of anatomical landmarks. In this monocentric prospective feasibility study, our aim was to evaluate predefined anatomical landmarks of the knee joint using needle arthroscopy (0° optics) and conventional knee arthroscopy (30° optics) and compare their performance during knee surgery. METHODS: Examinations were performed on eight cadavers and seven patients who required elective knee arthroscopy. Two surgeons independently performed the examinations on these 15 knee joints, so that we were able to compare a total of 30 examinations. The focus was on the anatomical landmarks that could be visualized during a conventional diagnostic knee arthroscopy procedure. The quality of visibility was evaluated using a questionnaire. RESULTS: In summary, the average visibility for all the anatomic landmarks was rated 4.98/ 5 for the arthroscopy using 30° optics. For needle arthroscopy, an average score of 4.89/ 5 was obtained. Comparatively, the needle arthroscope showed slightly limited visibility of the retropatellar gliding surface in eight (4.5/ 5 vs. 5/ 5), medial rim of the patella in four (4.85/ 5 vs. 5/ 5), and suprapatellar recess in four (4.83/ 5 vs. 5/ 5) cases. Needle arthroscopy was slightly better at visualizing the posterior horn of the medial meniscus in four knee joints (4.9/ 5 vs. 4.85/ 5). CONCLUSION: Needle arthroscopy is a promising technology with advantages in terms of minimally invasive access and good visibility of anatomical landmarks. However, it also highlights some limitations, particularly in cases with challenging anatomy or the need for a wide field of view.

A comparison between a maximum care university hospital and an outpatient clinic - potential for optimization in arthroscopic workflows?

BACKGROUND: Due to the growing economic pressure, there is an increasing interest in the optimization of operational processes within surgical operating rooms (ORs). Surgical departments are frequently dealing with limited resources, complex processes with unexpected events as well as constantly changing conditions. In order to use available resources efficiently, existing workflows and processes have to be analyzed and optimized continuously. Structural and procedural changes without prior data-driven analyses may impair the performance of the OR team and the overall efficiency of the department. The aim of this study is to develop an adaptable software toolset for surgical workflow analysis and perioperative process optimization in arthroscopic surgery. METHODS: In this study, the perioperative processes of arthroscopic interventions have been recorded and analyzed subsequently. A total of 53 arthroscopic operations were recorded at a maximum care university hospital (UH) and 66 arthroscopic operations were acquired at a special outpatient clinic (OC). The recording includes regular perioperative processes (i.a. patient positioning, skin incision, application of wound dressing) and disruptive influences on these processes (e.g. telephone calls, missing or defective instruments, etc.). For this purpose, a software tool was developed ('s.w.an Suite Arthroscopic toolset'). Based on the data obtained, the processes of the maximum care provider and the special outpatient clinic have been analyzed in terms of performance measures (e.g. Closure-To-Incision-Time), efficiency (e.g. activity duration, OR resource utilization) as well as intra-process disturbances and then compared to one another. RESULTS: Despite many similar processes, the results revealed considerable differences in performance indices. The OC required significantly less time than UH for surgical preoperative (UH: 30:47 min, OC: 26:01 min) and postoperative phase (UH: 15:04 min, OC: 9:56 min) as well as changeover time (UH: 32:33 min, OC: 6:02 min). In addition, these phases result in the Closure-to-Incision-Time, which lasted longer at the UH (UH: 80:01 min, OC: 41:12 min). CONCLUSION: The perioperative process organization, team collaboration, and the avoidance of disruptive factors had a considerable influence on the progress of the surgeries. Furthermore, differences in terms of staffing and spatial capacities could be identified. Based on the acquired process data (such as the duration for different surgical steps or the number of interfering events) and the comparison of different arthroscopic departments, approaches for perioperative process optimization to decrease the time of work steps and reduce disruptive influences were identified.

Combined Humeral Head and Shaft Fractures: Outcome Following Intramedullary Nailing and Plating.

Background and Objectives: Combined fractures of the humeral head and shaft (FHS) are rare but frequently involve an intermuscular fracture as its characteristic pattern. The aim of this retrospective study was to investigate intramedullary nailed and plated FHS in terms of outcomes and complications. Materials and Methods: The present study included patients with FHS, treated via either intramedullary nailing or plating within a period of 10 years, with a minimum follow-up of 12 months. Functional outcome was assessed using the age- and sex-adapted Constant-Murley Score (CMS-K). Rates of complications and revision surgeries were registered. Results: Twenty-five patients (18 females, 7 males, age 60.1 ± 14.2 years, range 23-76 years) were included in the study. Nailing was performed in 16 patients (12 females, 4 males, age 62.6 ± 12.4 years), whereas plating was executed in nine patients (6 females, 3 males, age 55.8 ± 17.0 years). Follow-up among all patients was 45.1 ± 26.3 months (range 12-97 months). CMS-K was 70.3 ± 32.3 in the nailing group, with reoperation in four cases, and 76.0 ± 31.0 in the plating group, with one reoperation (p = 0.42). Patients with no metaphyseal fragment displacement (n = 19; CMS-K 76.7 ± 17.3) demonstrated significantly better functional outcomes versus those with secondary displacement of the metaphyseal fragments (n = 6; CMS-K 60.0 ± 17.1), p = 0.046. Conclusions: Comparable acceptable clinical outcome is obtained when comparing nailing with additional open cerclage or lag-screw fixation techniques versus plating with open reduction. However, a higher revision rate was observed after nailing. The correct metaphyseal fragment fixation seems to be crucial to avoid loss of reduction and hence the need for revision surgery, as well as a worse outcome.

Levator scapulae and rhomboid minor are united.

Pain over the superior angle of the scapula is a common musculoskeletal symptom. It is often accompanied by radiating pain to the neck, head, and shoulder. The aetiologies can be varied but may also be idiopathic in nature. To explore the fascial connections of this region, we studied 26 unembalmed, -two Thiel and one alcohol body-donors of science, by dissection, histological probes, and plastinations. When removing the descending and transverse fibres of the trapezius, a large prominent triangular area of white connectives is revealed, varying in mass. A subdivision of these connectives can be further dissected to prove that the rhomboid minor and levator scapulae muscles are interconnected and enclosed by connectives. Between these two muscles a bridge of connective tissue, containing fat, is observed. These connectives end cranially at the surface of the splenius capitis, and at the midline, containing vessels and nerves, as supported by histology and plastinations. This unification is separate from the rhomboid major muscle but overlaps with the latter dorsally. It connects to the superior angle of scapula and its upper medial borders, respectively, and cranially to the root of the spine of the scapula. Beneath the united levator scapulae and rhomboid minor, described here, the serratus posterior superior and possibly serratus anterior form a hypomochlion or fulcrum at the superior angle of the scapula. Any tension on this unified entity can unbalance this fulcrum. Investigating the connections between these two unified muscles may help explain the often idiopathic nature of superior scapular pain, and the success or failure of surgery, and other treatments.

Methods for bone quality assessment in human bone tissue: a systematic review.

BACKGROUND: For biomechanical investigations on bone or bone implants, bone quality represents an important potential bias. Several techniques for assessing bone quality have been described in the literature. This study aims to systematically summarize the methods currently available for assessing bone quality in human bone tissue, and to discuss the advantages and limitations of these techniques. METHODS: A systematic review of the literature was carried out by searching the PubMed and Web of Science databases from January 2000 to April 2021. References will be screened and evaluated for eligibility by two independent reviewers as per PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Studies must apply to bone quality assessment with imaging techniques, mechanical testing modalities, and compositional characterization. The terms used for the systematic search were: "(bone quality". Ti,ab.) AND "(human bone specimens)". RESULTS: The systematic review identified 502 relevant articles in total. Sixty-eight articles met the inclusion criteria. Among them, forty-seven articles investigated several imaging modalities, including radiography, dual-energy X-ray absorptiometry (DEXA), CT-based techniques, and MRI-based methods. Nineteen articles dealt with mechanical testing approaches, including traditional testing modalities and novel indentation techniques. Nine articles reported the correlation between bone quality and compositional characterization, such as degree of bone mineralization (DBM) and organic composition. A total of 2898 human cadaveric bone specimens were included. CONCLUSIONS: Advanced techniques are playing an increasingly important role due to their multiple advantages, focusing on the assessment of bone morphology and microarchitecture. Non-invasive imaging modalities and mechanical testing techniques, as well as the assessment of bone composition, need to complement each other to provide comprehensive and ideal information on the bone quality of human bone specimens.

Online consultation in an orthopedic trauma surgery outpatient clinic: is there a learning curve?

BACKGROUND: In the context of the German contact restrictions due to the COVID-19 pandemic of March 2020, an online-based consultation system was established in our university orthopedic outpatient department to maintain patient care. As a basis for contact-minimizing communication, this was continued after the contact restrictions were lifted. The aim of this prospective pilot study was to assess the effectiveness, technical feasibility, and patient flow in this system under lockdown conditions and in the period afterwards. METHODS: The evaluation took place from the beginning of the first lockdown on March 13, 2020, until May 31, 2021. For each patient encounter, the quality of the sound and video connections was documented. The outcomes of the consultations were recorded. Four categories were distinguished: 1) no follow-up necessary, 2) follow-up via online consultation, 3) referral for surgical therapy, and 4) follow-up in the outpatient clinic for physical examination. A comparison was made between an early cohort right after implementation of the online consultation and and a late cohort after establishment of the consultation. RESULTS: There were 408 patient encounters via online consultation. A total of 360 (88%) consultations were uninterrupted. Initial presentations accounted for 124 (30%) consultations. In 75 (18%) patients, no further follow-up was necessary. Follow-up via online consultation was scheduled in 82 (20%) patients, direct referral for surgery was made in 86 (21%) patients, and a follow-up for physical examination was arranged in 165 (40%) patients. When comparing the early and late cohort, there was no difference in the duration of the conversation (p = 0.23). A significant difference was found in the type of further treatment. In the late cohort, conservative therapy was used more often (p < 0.01), resulting in a lower number of follow-up visits for clinical examination (p < 0.01). CONCLUSION: While a definite decision for further procedure was possible solely by online consultation in a large percentage of cases, 40% of patients still needed an additional in-person consultation for physical examination. A learning curve could be observed regarding the selection of patients suited for online consultation. Overall, online consultation is a useful measure to manage patient volume and to visibly support direct doctor-patient contact.

Intraoperative hyperspectral imaging (HSI) as a new diagnostic tool for the detection of cartilage degeneration.

To investigate, whether hyperspectral imaging (HSI) is able to reliably differentiate between healthy and damaged cartilage tissue. A prospective diagnostic study was performed including 21 patients undergoing open knee surgery. HSI data were acquired during surgery, and the joint surface's cartilage was assessed according to the ICRS cartilage injury score. The HSI system records light spectra from 500 to 1000 nm and generates several parameters including tissue water index (TWI) and the absorbance at 960 nm and 540 nm. Receiver operating characteristic curves were calculated to assess test parameters for threshold values of HSI. Areas with a cartilage defect ICRS grade ≥ 3 showed a significantly lower TWI (p = 0.026) and higher values for 540 nm (p < 0.001). No difference was seen for 960 nm (p = 0.244). For a threshold of 540 nm > 0.74, a cartilage defect ICRS grade ≥ 3 could be detected with a sensitivity of 0.81 and a specificity of 0.81. TWI was not suitable for cartilage defect detection. HSI can provide reliable parameters to differentiate healthy and damaged cartilage. Our data clearly suggest that the difference in absorbance at 540 nm would be the best parameter to achieve accurate identification of damaged cartilage.

Anatomical versus non-anatomical configuration of double coraco-clavicular tunnel technique in acromioclavicular joint reconstruction.

PURPOSE: Horizontal instability is a common problem after acromioclavicular joint injuries. The aim of this study was to evaluate if there is a difference regarding horizontal stability between an anatomical and a non-anatomical configuration of the double tunnel coraco-clavicular ligament reconstruction of the acromioclavicular joint. METHODS: Thirteen acromioclavicular joints of human cadaveric shoulders in ethanol-glycerin fixation were included in the study and underwent cyclic anterior and posterior translational testing at a load of 70 N using an electromechanical uniaxial testing machine. The shoulders were randomly assigned to the following groups: double coraco-clavicular tunnel technique in an anatomical configuration (DCTa) and double coraco-clavicular tunnel technique in an inverse configuration of the anatomical position (DCTb). The dislocation was recorded with a 3D optical measuring system. RESULTS: The total horizontal displacement (p10 = 0.0221; p5000 = 0.082) was significantly higher for the non-anatomical reconstruction (DCTb) compared to the anatomical reconstruction (DCTa) after every measured amount of cycles. The increase in displacement for DCTb group was overall higher than the increase in displacement for DCTa group but without significance. CONCLUSION: Reconstruction of the CC ligaments in an anatomical configuration with two suture devices results in a significantly higher stability of the AC joint in the horizontal plane than reconstruction of the CC ligaments in a non-anatomical configuration. Based on the results of this biomechanical in vitro study, the use of a double coraco-clavicular reconstruction should focus on an anatomically correct position of the suture devices.

[Video consultation in an orthopedic trauma surgery outpatient clinic : Effective adjunctive interventions in lockdown and post-lockdown scenarios-a prospective pilot study]. / Die Videosprechstunde in einer unfallchirurgisch/orthopädischen Spezialsprechstunde : Effektive ergänzende Maßnahme in Lockdown- und Post-Lockdown-Szenarien ­ eine prospektive Pilotstudie.

BACKGROUND: With the regulation of the Saxon State Government and the Saxon State Ministry for Social Affairs and Social Responsibility on the modification of the Infection Protection Act of March 2020 coming into force, a video-based outpatient consultation was implemented to maintain patient care. In order to allow communication with minimized contact, this was continued after the lockdown. AIM OF THE WORK: The aim of this prospective pilot study was to assess the effectiveness of a video-based outpatient consultation service, technical feasibility and control of patient flow under both lockdown and post-lockdown conditions. MATERIAL AND METHODS: The initial evaluation was conducted up to 14 December 2020 when the second restrictive measures were implemented by the state government. The quality of the connections regarding sound and image was documented. Furthermore, the consequences of the conversations were documented. Distinctions were made in four categories: 1. no follow-up visit, 2. follow-up via video consultation, 3. operative intervention and 4. in-person follow-up visit for clinical examination. RESULTS: There were 236 video-based outpatient consultations, 182 (82%) consultations were without restrictions and 47 (21%) consultations were initial presentations. There were no follow-up consultations in 41 (18%) patients. Video-based follow-up was scheduled in 36 (16%) patients, direct referral for surgery in 36 (16%) patients, and in-person follow-up in 105 (47%) patients. DISCUSSION: In 40% of the patients a definite decision could be made by the initial video-based consultation alone. On the other hand, 47% of the patients needed in-person follow-up for a clinical examination. Thus, video consultation is a very useful measure to manage patient volume and visibly support direct doctor-patient contact.

Comorbidities, substance abuse, weight and age are independent risk factors for postoperative complications following operation for proximal humerus fractures: a retrospective analysis of 1109 patients.

INTRODUCTION: This study aimed to investigate the influence of epidemiologic parameters on complications that needed operative revision of operatively treated proximal humerus fractures. METHODS: We performed a retrospective single-center study in a level 1 trauma center. We included all patients with operatively treated proximal humerus fractures from January 1 2005 to December 31 2015. We characterized our cohort and subgroup using descriptive statistics. The primary outcome was postoperative complications. For this purpose, postoperative complications were defined in advance, an operative revision was necessary on a general rule. The secondary outcome was a model of the risk factors for complications created with multiple logistic regression. RESULTS: We included 1109 patients. The average age was 67.2 years (± 16.4), and 71.4% of the fractures occurred in women. A total of 644 patients (58.1%) had between one to three comorbidities, and 27.8% had four or more. The fracture morphology was as follows: 3 part 41.8%, 4 part 26.9%, 2 part 24.3%, and dislocation fracture 6.7%. Complications occurred in 150 patients (13.5%). The number of comorbidities [odds ratio (OR) 2.85, p < 0.01], body weight (OR 1.15, p = 0.02), and substance abuse (OR 1.82, p = 0.04) significantly correlated with the risk of complications. We achieved a sensitivity of 48% and a specificity of 74% for the variables body weight, substance abuse, age, and comorbidities CONCLUSION: The epidemiologic parameters, comorbidities, substance abuse, weight, and age are independent risk factors for complications. If these factors are present, one can predict a postoperative complication requiring surgical revision with low sensitivity and moderate specificity. Therefore, concerning the high number of multi-morbid patients with proximal humerus fractures, an increased postoperative complication rate can be expected. LEVEL OF EVIDENCE: Level of evidence IV.

Supraspinatus tendon reconstruction using open infraspinatus tendon shift and autologous biceps tendon interposition grafts.

INTRODUCTION: Inferior tendon quality, wide retraction, and tendon stumps that cannot be mobilized define the limits of what is technically feasible for open and arthroscopic rotator cuff reconstruction. The aim of this study was to develop a procedure that enables the open reconstruction of otherwise non-reconstructable rotator cuff tears. METHODS: From 2014 to 2018, 23 operations were performed on 21 patients (mean age 63) using open procedure involving separating the infraspinatus tendon from the point of insertion on the greater tubercle and mobilizing it proximally and ventrally into the defective area. Any remaining defects were augmented using an autologous biceps tendon interposition graft. This augmentation was performed to achieve complete closure of the defect. Furthermore, the augmentation of the rupture zone was intended to strengthen the tendon stumps of the SSP and ISP to better neutralize the initial tensile forces. After a postoperative period of 12 months-4 years, clinical examination and functional tests were carried out, the Constant score was determined, and radiological and magnetic resonance imaging check-up examinations were performed. RESULTS: The technique resulted in a low-tension closure of an otherwise "non-repairable" superior rotator cuff defect. All patients experienced a significant functional improvement, a reduction in pain, and an increase in muscle strength. An improvement in the Constant score from 48 points preoperatively to 87 points postoperatively (p < 0.05) was observed. In 19 patients (90%), the magnetic resonance image showed an intact reconstruction. Re-rupture was seen in three patients (14%). CONCLUSION: The surgical procedure using infraspinatus tendon shift and autologous biceps tendon interposition grafts resulted in the successful reconstruction of otherwise non-reconstructable massive rotator cuff lesions. The complete closure of the defect was observed.

Clinical outcomes of arthroscopic and navigation-assisted two tunnel technique for coracoclavicular ligament augmentation of acute acromioclavicular joint dislocations.

BACKGROUND: The purpose of this study was to present a navigated image-free augmentation technique for the acromioclavicular joint (ACJ) and coracoclavicular (CC) ligaments and to report the clinical and radiological outcomes. METHODS: From 2013 to 2018, 35 eligible patients were treated with our navigated image-free ACJ- and CC-augmentation technique. The average follow-up was 3 years. Follow-up evaluations included the Constant-Murley Score, subjective shoulder value, Taft score, and the acromioclavicular joint instability (ACJI) score. The patients' quality of life was assessed using the EuroQol-5D (EQ-5D) questionnaire. In addition, in accordance with the instability criteria, radiographs were evaluated before surgery, after surgery, and during follow-up. RESULTS: Overall, 25 patients (71%) suffered an acute type V disruption, 5 (14%) had a type IV disruption, and 5 (14%) had an acute Rockwood type IIIb injury. The mean Constant-Murley Score was 90 (range: 56-100; p = 0.53) on the injured side, and the mean subjective shoulder value was 92% (range: 80-100%). The mean Taft and ACJI scores were 10 (range: 4-12) and 86 (range: 34-100), respectively and the mean EQ-5D was 86 (range: 2-100). The mean CC difference of the injured side was 4 mm (range: 1.9-9.1 mm) at follow-up, which was not significantly different than that of the healthy side (p = 0.06). No fractures in the area of the clavicle or the coracoid were reported. CONCLUSIONS: The arthroscopic- and navigation-assisted treatment of high-grade ACJ injuries in an anatomical double-tunnel configuration yields similar clinical and radiological outcomes as the conventional technique using an aiming device. Precise positioning of the navigation system prevents multiple drillings, which avoids fractures.

[How badly is the coronavirus pandemic affecting orthopaedic and trauma surgery clinics? : An analysis of the first 5 weeks]. / Wie stark trifft die Corona-Pandemie die Kliniken für Orthopädie und Unfallchirurgie? : Eine Analyse der ersten 5 Wochen.

BACKGROUND: The corona pandemic poses enormous financial challenges for hospitals. Using the example of a clinic for orthopaedics and trauma surgery, the performance development of the first 5 weeks in comparison to last year and an evaluation of the compensation measures laid down by law will be evaluated. METHODOLOGY: Based on the performance figures, a comparison is made between the period 16.03 to 17.04.2019 and the same period in 2020. Changes in the number of cases, case mix, case-mix index and day-mix index, as well as the occupancy days are recorded. The monetary measures from the COVID-19 Hospital Relief Act are applied to these changes, and the adequacy is evaluated. RESULTS: Compared to last year, there was a decrease in inpatient admissions of n = 307 patients in the observation period. As a result, there was a decrease of 595 points in case mix and 2320 days of occupancy. This results in a decrease in revenue of approximately EUR 1.9 million. The flat rate for empty beds represents the largest monetary compensation for the loss of revenue. It amounts to approximately EUR 1.3 million. Taking into account further support and an adjustment for variable costs, a deficit of EUR 382,069 remains for 5 weeks. DISCUSSION: The measures taken by the Government are an important pillar for the economic security of German hospitals. The lack of differentiation of measures by specialty leads to insufficient compensation for orthopaedics and trauma surgery.

The single-suture technique for anterior cruciate ligament graft preparation provides similar stability as a three-suture technique: a biomechanical in vitro study in a porcine model.

PURPOSE: Numerous techniques have been described for the tibial-sided graft preparation in anterior cruciate ligament (ACL) reconstruction. The use of less suture material for graft preparation is thought to improve ingrowth and to reduce the risk for infection. At the same time, the suture construct should be strong enough to resist the surgeon's pull during tensioning of the transplant. METHODS: In total, 39 fresh-frozen procine deep flexor tendons were used and prepared as four-strand grafts. In the three-suture group (n = 19), graft preparation was performed using three tibial-sided sutures, with each tendon end sutured separately. In the one-suture group (n = 20), a modified graft preparation using only one tibial-sided suture was applied. Each sample underwent load-to-failure testing (Nmax) after cyclic pre-loading. To estimate intraoperative tension forces acting on the tibial-sided suture constructs, the maximal tension force of 26 volunteers on such a construct was measured using a load cell. RESULTS: The biomechanical testing of the two different suture constructs showed a significantly higher load-to-failure for the three-suture group (711 N ± 91 N) compared to the one-suture group (347 N ± 24 N) (p = 0.0001). In both groups, the mode of failure was a tear of the suture in all samples. A failure of the suture-tendon interface was not observed in any case. The median maximal tension force on the construct applied by the 26 volunteers was 134 N (range 73-182 N). CONCLUSION: The presented single-suture tendon graft preparation resisted to smaller failure loads than the conventional three-suture technique. However, no failures in the suture-tendon interface were seen and the failure loads observed were far beyond the tension forces that can be expected intraoperatively. Hence, the single-suture graft preparation technique may be a valuable alternative to the conventional technique.

Nontraumatic avascular necrosis of the femoral head : Arthroscopic and navigation-supported core decompression.

OBJECTIVE: The aim is to address core decompression and pathologies of the femoral head, treating them during the same procedure. Furthermore, radiation exposure will be reduced. INDICATIONS: Femoral head necrosis ARCO (Association Research Circulation Osseous) stages I-III. CONTRAINDICATIONS: Progressive femoral head necrosis as ARCO stages IIIC-IV. SURGICAL TECHNIQUE: Arthroscopically navigated core decompression of the femoral head using an established optoelectronic system with fluoro-free software module. First, hip joint arthroscopy was performed and further pathologies were treated. Second, core decompression was navigated by a navigation pointer and drill sleeve to reach the correct target point. After visualization, the procedure is repeated 3-5 times. POSTOPERATIVE MANAGEMENT: Limited weight bearing of the operated leg (20 kg) for 10-14 days. Active or passive continuous motion machine for 4 weeks. Adjuvant postoperative indomethacin therapy for 10 days to reduce pain and bone marrow edema. RESULTS: From May 2018 to January 2019, 7 patients (male = 4; 40 ± 9 years) underwent arthroscopically navigated core decompression with 2 (29%) and 5 (71%) patients being classified as ARCO II and III, respectively. Preoperatively, all patients reported load-dependent pain. In all cases, we could identify synovitis, which results in soft tissue release and synovectomy. Furthermore, 4 of 7 patients had an additional labrum lesion, which is addressed by refixation or shrinking. DISCUSSION: Compared to the conventional technique, this fluoro-free navigation procedure allows more precise drilling. Moreover, additional pathologies, as found in all our cases, could be simultaneously addressed. The intraoperative radiation exposure for the patient and surgical team could also be reduced. Although arthroscopically assisted core decompression requires more preparation time, there are advantages over conventional surgery.

Acromioclavicular joint reconstruction: an additional acromioclavicular cerclage does not improve horizontal stability in double coraco-clavicular tunnel technique.

PURPOSE: Horizontal instability-especially in the posterior plane-is a common problem after acromioclavicular joint injuries. The purpose was to compare the stability of a single coraco-clavicular tunnel technique and a double coraco-clavicular tunnel technique for coraco-clavicular ligament reconstruction and to examine the influence of an additional acromioclavicular cerclage on the horizontal stability in the acromioclavicular joint. METHODS: 21 acromioclavicular joints of human cadaveric shoulders were randomly assigned to the following groups: single coraco-clavicular tunnel technique with horizontal augmented acromioclavicular cerclage (SCT + AC); double coraco-clavicular tunnel technique (DCT); double coraco-clavicular tunnel technique and acromioclavicular cerclage (DCT + AC). The specimens underwent cyclic horizontal testing and were recorded using a 3D optical measuring system. RESULTS: The displacement and the increase in displacement in relation to the displacement after precondition for SCT + AC were significantly higher after every measured amount of cycles than for DCT (p10 = 0.0023; p5000 = 0.0012) and DCT + AC (p10 = 0.0006; p5000 = 0.0012). There was no significant difference in the total displacement, or in the increase in total displacement between double coraco-clavicular tunnel reconstructed groups with and without additional acromioclavicular cerclage. CONCLUSION: Double coraco-clavicular tunnel technique with and without additional acromioclavicular cerclage results in a significant higher stability regarding the horizontal plane in comparison to single coraco-clavicular tunnel technique with acromioclavicular cerclage. Based on the results of this biomechanical in vitro study, the use of an additional acromioclavicular cerclage with single coraco-clavicular tunnel technique may not be indicated in most cases. The effect of an additional acromioclavicular cerclage seems to be negligible, at least in presence of a double-coraco-clavicular tunnel technique reconstruction. Techniques of AC joint reconstruction should focus on the use of double coraco-clavicular tunnel devices.

Real-time intraoperative 3D image intensifier-based navigation in reversed shoulder arthroplasty- analyses of image quality.

BACKGROUND: Due to the high anatomical variability and limited visualization of the scapula, optimal screw placement for baseplate anchorage in reversed total shoulder arthroplasty (rTSA) is challenging. Image quality plays a key role regarding the decision of an appropriate implant position. However, these data a currently missing for rTSA and were investigated in the present study. Furthermore, the rate of required K-wire changes for the central peg as well as post-implantation inclination and version were assessed. METHODS: In ten consecutive patients (8 female, 86 years, range 74-94) with proximal humeral fracture and indication for rTSA, an intraoperative 3D-scan of the shoulder with a 3D image intensifier (Ziehm Vision FD Vario 3D© [Ziehm Imaging GmbH, Nürnberg, Germany]) was performed after resection of the humeral head. Using the Vectorvision© Software (Brainlab AG, Feldkirchen, Germany), the virtual anatomy was compared to the visible anatomical landmarks. After implantation of the baseplate, a 3D scan was performed. All 3D scans included multiplanar reconstruction (MPR) and the cinemode to examine screw and baseplate placement. The rate of required K-wire changes was assessed. The intraoperative 3D image quality (modified visual analogue scale [VAS] and point system) was assessed before and after implantation of the glenoid component. Inclination and version were determined in post-implantation scans. RESULTS: The virtually presented anatomical landmarks always correlated to the anatomical visible points indicating an good virtual accuracy. The central K-wire position was corrected in three cases due to a deviation from the face plane technique position. The VAS was higher for the pre-implantation MPR (6.7, range 5-8) compared to the post-implantation acquired MPR (5.1, range 4-6; p = 0.0002). The point system showed a reduced quality in all subcategories, especially regarding the grading of the articular surfaces. The preoperative (7.9, range 6-9) and post-implantation (7.9, range 6-9) cinemode displayed no significant differences (p = 0.6). CONCLUSION: The present study underlines the need for the improvement of 3D image intensifiers algorithms to reduce artifact associated impaired image quality to enhance the benefit of real-time intraoperative 3D scans and navigation.

Risk factors for early infection following hemiarthroplasty in elderly patients with a femoral neck fracture.

PURPOSE: Periprosthetic joint infections (PJI) after hemiarthroplasty for geriatric femoral neck fractures are a devastating complication that results in serious morbidity and increased mortality. Identifying risk factors associated with early infection after HA for hip fractures may offer an opportunity to address and prevent this complication in many patients. The aim of this study was to evaluate preoperative risk factors for early PJI after HA in hip fracture patients. METHODS: From January 2010 to December 2015, 312 femoral neck fractures (AO/OTA 31-B) in 305 patients were included in this single-center, retrospective study. PJI was defined according to the Centers for Disease Control (CDC) definition of deep incisional surgical site infection. Early infection referred to a postoperative period of 4 weeks. Binary univariable and multivariable regression analysis with backward elimination was applied to identify predictors of PJI. RESULTS: Median age of all patients was 83.0 (IQR 76-89) years. We identified 16 (5.1%) early PJI which all required surgical revision. Median length of in-hospital stay (LOS) was 20.0 (IQR 10-36) days after PJI compared to 10.0 (8-15) days without deep wound infection. In-hospital mortality was 30.8 vs. 6.6%, respectively. Preoperative CRP levels (OR 1.009; 95% CI 1.002-1.018; p = 0.044), higher BMI (OR 1.092; 95% CI 1.002-1.189; p = 0.044) and prolonged surgery time (OR 1.013; 95% CI 1.000-1.025; p = 0.041) were independent risk factors for PJI. Excluding infection following major revision due to mechanical complications identified preoperative CRP levels (OR 1.012; 95% CI 1.003-1.021; p = 0.007) and chronic glucocorticoid therapy (OR 6.314; 95% CI 1.223-32.587; p = 0.028) as risk factors, a clear trend was seen for higher BMI (OR 1.114; 95% CI 1.000-1.242; p = 0.051). A cut-off value at CRP levels ≥ 14 mg/l demonstrated a sensitivity of 69% and a specificity of 70% with a fair accuracy (AUC 0.707). CONCLUSION: Preoperative serum CRP levels, higher BMI and prolonged surgery time are independent predictors of early PJI. Excluding PJI secondary to major revision surgery revealed chronic glucocorticoid use as a risk factor apart from preoperative CRP levels.