Incidence and management of secondary deformities after megaendoprosthetic proximal femur replacement in skeletally immature bone sarcoma patients.

INTRODUCTION: Megaendoprosthetic reconstruction of bone defects in skeletally immature patients has led to the development of unique complications and secondary deformities not observed in adult patient cohorts. With an increasing number of megaendoprosthetic replacements performed, orthopedic oncologists still gain experience in the incidence and type of secondary deformities caused. In this study, we report the incidence, probable cause and management outcome of two secondary deformities after megaendoprosthetic reconstruction of the proximal femur: hip dysplasia and genu valgum. MATERIALS AND METHODS: Retrospective analysis of 14 patients who underwent primary and/or repeat reconstruction/surgery with a megaendoprosthetic proximal femur replacement between 2018 and 2022. RESULTS: Mean patient age was 9.1 years (range 4-17 years). Stress shielding was observed in 71.4%. Hip dislocation was the most frequent complication (50%). While four dislocations occurred without an underlying deformity, secondary hip dysplasia was identified in 58.3% (n = 7/12) of intraarticular resections and reconstructions, leading to dislocation in 71.4% (n = 5/7). A genu valgum deformity was observed in 41.6% (n = 5/12). The incidence of secondary hip dysplasia and concomitant genu valgum was 42.9% (n = 3/7). Triple pelvic osteotomy led to rebound hip dysplasia in two cases (patients aged < 10 years), whereas acetabular socket replacement led to stable hip joints over the course of follow-up. Temporary hemiepiphyseodesis was applied to address secondary genu valgum. CONCLUSIONS: Patients aged < 10 years were prone to develop secondary hip dysplasia and genu valgum following proximal femur replacement in this study. Management of secondary deformities should depend on remaining skeletal growth. Stress shielding was observed in almost all skeletally immature patients.

[Plastering-A technique fallen into obscurity]. / Gipsen ­ eine in Vergessenheit geratene Technik.

Immobilization of fractures and dislocations is a basic technique in orthopedic trauma surgery care. The orthopedic surgeon should be familiar with the various materials, techniques and possible complications. Despite other techniques, the classical white plaster cast remains an integral part of orthopedic trauma surgery care. The application of such a cast must be learned as failure to observe the basic principles can result in harm to the patient. In many hospitals, the application of a plaster cast is delegated to the nursing staff according to the physician's instructions. As a result, many young medical colleagues lack the knowledge of how to apply a plaster cast. In addition to the treatment of fractures, immobilization after dislocation, inflammation and ligamentous injuries are some of the areas of application. In this article the application of a plaster cast is described based on a case study, from the indications to the execution and possible complications.

Posterior pelvic ring injuries, lumbosacral junction instabilities and stabilization techniques for spinopelvic dissociation: a narrative review.

INTRODUCTION: From transiliac Harrington rods to minimally invasive (MIS) percutaneous 3D-navigated transsacral-transiliac screw (TTS) fixation, concepts of fixation methods in pelvic injuries with spinopelvic dissociation (SPD) are steadily redefined. This narrative review examines the literature of recent years regarding surgical treatment options and trends in SPD, outlining risks and benefits of each treatment option and addressing biomechanical aspects of sacral injuries and common classification systems. MATERIALS AND METHODS: A literature search on the search across relevant online databases was conducted. As a scale for quality assessment, the SANRA-scoring system was taken into account. RESULTS: Sacral Isler type 1 injuries of the LPJ in U- and H-type fractures are frequently treated with stand-alone TTS. Fractures with higher instability (Isler types 2 and 3) require unilateral or bilateral LPF, subject to side involvement, as a buttressing construct, or triangular fixation as additional compression and neutralization, determined by fracture radiation. A more comprehensive classification from which to derive stabilization options is provided by the 2023 301SPD classification. MIS techniques are on the rise and offer shorter OR time, less blood loss, fewer infections, and fewer wound complications. It is advisable to implement MIS techniques as much as possible, as long as decompression is not required and closed fracture reduction succeeds satisfactorily. CONCLUSION: SPD is characteristic of severe injuries, mostly in polytraumatized patients. The complication rates are decreasing due to the increasing adaptation of MIS techniques.

[Complications after conservative vs. operative treatment of severe thoracic trauma]. / Komplikationen nach operativer vs. konservativer Versorgung des schweren Thoraxtraumas.

BACKGROUND: Thoracic trauma is a frequent injury in the routine treatment of injured patients. Due to the increasing demographic changes a further increase is to be expected, especially after low-energy trauma. OBJECTIVE: Expected complications after conservative vs. operative treatment of various injury patterns of thoracic trauma. MATERIAL AND METHODS: Evaluation of a selective literature search regarding possible complications after thoracic trauma and formulation of instructions for action as expert recommendations. CONCLUSION: Both conservative and operative treatment of thoracic trauma have their specific complications, which have to be known to the treating physician. Lung contusions are often underestimated in the initial radiological diagnostics but often lead to relevant problems during the further course of treatment. After conservative treatment of rib fractures persistent pain, functional limitations or even relevant deformities due to secondary dislocation, can remain. There is a significant risk of overlooking or underestimating relevant injuries during the initial diagnostics which then leads to secondary complications. By far the most frequent risk of surgical treatment is an incorrect positioning of chest tubes. Overall, postoperative infections after chest trauma are relatively rare.

The Megaendoprosthesis in Revision Arthroplasty - a Cost-revenue Analysis in the aG-DRG System. / Die Megaendoprothese im Revisionsfall ­ eine Kosten-Erlös-Analyse im aG-DRG-System.

Megaendoprosthesis offer a viable treatment in complex revision arthroplasty cases with good functional outcome. In the context of a neoplastic indication, the diagnosis-related group (DRG) I95A is usually assigned with a relative weight of 4.906 (2021). In contrast, in revision arthroplasty, the appropriate DRG is assigned, depending on the joint replacement. The additional costs compared to the invoiced DRG are to be compensated by agreeing on hospital-specific individual fees. These complex revision arthroplasties set high technical and operative demands and are mainly performed in specialised departments. We conducted a cost-benefit analysis of the use of the megaendoprosthesis in revision cases in a specialised orthopaedic clinic, as a single centre study. The question we sought to answer was: Is cost recovery possible in the modified German DRG system (aG-DRG)?A retrospective single centre analysis of treatment costs was performed. From 2018 to 2020, 113 patients treated with a megaendoprosthesis reconstruction in a referral centre due to extensive bone loss after aseptic or septic revision of a hip or knee prosthesis were included in the study. Relevant case-related cost drivers of the aG-DRG matrix (including staff and material costs of the operating theatre area and the ward) were taken into account. The actual costs were determined according to the specifications of the calculation manual published by the German institute for the remuneration system in hospitals (InEK). For each case, the contribution margin was calculated by relating the hospital's internal costs to the corresponding cost pool of the aG-DRG matrix.According to the DRG system 2021, 17 different DRGs were used for billing - in 70% based on a patient clinical complexity level (PCCL) ≥ 4. Compared with the InEK calculation, there is a deficit of -2,901 € per case in the examined parameters. The costs of physicians show a shortfall in both the operating theatre and on the ward. Implant costs, which were supposed to be compensated by hospital-specific additional charges, show a hospital-specific shortage of -2,181 €. When analysing the risk factors for cost recovery, only these showed a significant difference.Implantation of the megaendoprosthesis in revision arthroplasty is often the last option to preserve limb function. At present, despite a high degree of specialisation and process optimisation, this treatment cannot be provided cost-effectively even in tertiary care. The politically desired specialised department structure requires sufficient reimbursement for complex cases. The economic outcome of each treatment case is often unpredictable, however the surgeon is confronted with these cases and is expected to treat them. The high standard deviation indicates large differences in the cost/revenue situation of each individual case. Our results show for the first time a realistic cost analysis for megaprosthesis in revision arthroplasty and underline the importance of an adequate hospital-specific charge, individually agreed by the funding units. The calculation should include not only the implant costs, but also the increased staff costs (increased, complex planning effort, quality management, surgery time, etc.).

Custom-Made Metaphyseal Sleeves in "Beyond" AORI III Defects for Revision Knee Arthroplasty-Proof of Concept and Short-Term Results of a New Technique.

BACKGROUND: While off-the-shelf cones and sleeves yield good results in AORI type 2 and 3 defects in revision knee surgery, massive longitudinal defects may require a proximal tibia replacement. To achieve the best anatomical as well as biomechanical reconstruction and preserve the tibial tuberosity, we developed custom-made metaphyseal sleeves (CMSs) to reconstruct massive defects with a hinge knee replacement. METHODS: Between 2019 and 2022, 10 patients were treated in a single-center study. The indication for revision was aseptic loosening in five cases and periprosthetic joint infection in five cases. The mean number of previous revisions after the index operations was 7 (SD: 2; 4-12). A postoperative analysis was conducted to evaluate the functional outcome as well as the osteointegrative potential. RESULTS: Implantation of the CMS in rTKA was carried out in all cases, with a mean operation time of 155 ± 48 (108-256) min. During the follow-up of 23 ± 7 (7-31) months, no CMS was revised and revisions due to other causes were conducted in five cases. Early radiographic evidence of osseointegration was recorded using a validated method. The postoperative OKS showed a significant increase (p < 0.001), with a mean score of 24 (SD: 4; range: 14-31). CONCLUSION: Custom-made metaphyseal sleeves show acceptable results in extreme cases. As custom-made components become more and more common, this treatment algorithm presents a viable alternative in complex rTKA.

Injuries and Overuse Syndromes in Rink Hockey Players.

Rink Hockey is a high-speed low-contact sport with a widely recognized injury potential. Played with a hard ball by players wearing little or no protective gear, the rates of concussions and head injuries are of high interest. In this study, we reviewed and investigated injuries sustained by 108 German National League rink hockey players. We conducted an epidemiological cross-sectional study to determine sport-specific injuries and injury patterns in female and male rink hockey players. Data were collected by a standardized questionnaire. A total of 108 players participated in the study. The combined rate of injuries were 9.4/1000 athlete exposures. There was no significant difference between injury rates during games and practice. A sexspecific difference was not detected. Head injuries were the most frequent type (20.8 % of all injuries). Concussions made up 7 % of all head injuries with a rate of 0.76/1000 athlete exposure. Ball contact was the cause for 31 % of injuries, while player contact generated 26.2 % of all injuries. High rates of ball-contact-related injuries resulted in time loss and medical consultations. Head injuries were frequent, however did not result in significant time loss as compared to other injuries. The use of protective gear should be recommended.

A salvage procedure: Radial head excision in children and adolescents-short-to-midterm outcomes and overview of the literature.

Purpose: Purpose of the study was to report the outcomes after radial head excision in children and adolescents in addition with a review of the current literature. Methods: We report a series of five children and adolescents, who had undergone a post-traumatic radial head excision. Clinical outcomes were evaluated in terms of elbow/wrist range of motion, stability, deformity and discomforts or restrictions at two follow-up points. Radiographic changes were evaluated. Results: Patient's age at time of the radial head excision averaged 14.6 (13-16) years. Mean time from the injury to the radial head excision was 3.6 (0-9) years. Follow-up I averaged 4.4 (1-8) years and follow-up II 8.5 (7-10) years. At follow-up I, patients showed an average elbow range of motion of 0-10-120° Ext/Flex and 90-0-80° Pro/Sup. Two patients reported discomfort or pain at the elbow. Four (80%) patients had a symptomatic wrist with pain or crepitation at the distal radio ulnar joint. In three (60%) of them, an ulna plus at the wrist was present. Two patients required ulna shortening and autograft stabilization of the interosseous membrane. At final follow-up, all patients reported full functioning with daily activities. Restrictions were present with sport activities. Conclusion: Functional results at the elbow joint might be improved and pain syndromes lessen due to the radial head excision. Problems at the wrist are likely secondary to the procedure. A critical analysis of other options should be performed ahead of the procedure and a careless application should be avoided by all means. Level of evidence: IV.

[Polytrauma care in air rescue in times of the COVID-19 pandemic: impact and development of case numbers]. / Polytraumaversorgung in der Luftrettung in Zeiten der COVID-19-Pandemie: Auswirkungen und Entwicklung der Fallzahlen.

Background: Changes in patient care occurred as a result of the SARS-CoV­2 virus, and both intrahospital and prehospital care were profoundly affected. Public shutdowns during lockdown periods were intended to prevent overstretching existing resources, resulting in noticeable changes in medical care for both elective treatments and emergency medicine. This study now considered the impact of the COVID 19 pandemic on air ambulance services at a central air ambulance site in 2020 compared to the previous 2 years. Methods: A retrospective evaluation of all missions of the rescue helicopter Christoph 9 in the first COVID-19 pandemic year 2020 in comparison to the years 2018 and 2019 was performed. The mission logs were evaluated for the analysis. Results: There was a 20% reduction in the number of missions in 2020, with primarily internal medicine missions affected. Despite the lockdown periods and reduction in social life, the proportion of trauma deployments remained nearly the same. As expected, the proportion of occupational accidents decreased, and recreational activities resulted in accidents more frequently. Injury or illness severity showed no significant differences. In terms of internal diseases, there was a reduction in alerts for acute coronary syndrome and respiratory emergencies. The proportion of suicide-related injuries remained constant over the years. Conclusion: During the COVID-19 study period, a decrease in the number of deployments and aborted deployments was observed. However, no significant differences in deployment and injury characteristics were observed for trauma-related deployments. These results highlight the importance of air ambulance services to ensure patient care even during pandemic periods.

The influence of distribution, severity and volume of posttraumatic bone bruise on functional outcome after ACL reconstruction for isolated ACL injuries.

INTRODUCTION: Posttraumatic MRI of ACL tears show a high prevalence of bone bruise (BB) without macroscopic proof of chondral damage. Controversial results are described concerning the association between BB and outcome after ACL tear. Aim of this study is to evaluate the influence of distribution, severity and volume of BB in isolated ACL injuries on function, quality of life and muscle strength following ACL reconstruction (ACLR). MATERIALS AND METHODS: MRI of n = 122 patients treated by ACLR without concomitant pathologies were evaluated. BB was differentiated by four localizations: medial/lateral femoral condyle (MFC/LFC) and medial/lateral tibial plateau (MTP/LTP). Severity was graded according to Costa-Paz. BB volumes of n = 46 patients were quantified (software-assisted volumetry). Outcome was measured by Lysholm Score (LS), Tegner Activity Scale (TAS), IKDC, isokinetics and SF-36. Measurements were conducted preoperatively (t0), 6 weeks (t1), 26 weeks (t2) and 52 weeks (t3) after ACLR. RESULTS: The prevalence of BB was 91.8%. LTP was present in 91.8%, LFC 64.8%, MTP 49.2% and MFC 28.7%. 18.9% were classified Costa-Paz I, 58.2% II and 14.8% III. Total BB volume was 21.84 ± 15.27 cm3, the highest value for LTP (14.31 ± 9.93 cm3). LS/TAS/IKDC/SF-36/isokinetics improved significantly between t0-t3 (p < 0.001). Distribution, severity and volume had no influence on LS/TAS/IKDC/SF-36/isokinetics (n.s.). CONCLUSIONS: No impact of BB after ACLR on function, quality of life and objective muscle strength was shown, unaffected by concomitant pathologies. Previous data regarding prevalence and distribution is confirmed. These results help surgeons counselling patients regarding the interpretation of extensive BB findings. Long-time follow-up studies are mandatory to evaluate an impact of BB on knee function due to secondary arthritis.

[Complex Regional Pain Syndrome (CRPS) - State of the Art in Diagnostics and Therapy]. / Complex Regional Pain Syndrome (CRPS).

The complex regional pain syndrome (CRPS) usually occurs within a few weeks in 2-5% of all patients after trauma or surgery or subsequent measures of the distal extremities. There are certain risk factors for its occurrence but no "CRPS personality", instead there are factors that negatively influence the course. The prognosis is generally good ("rule of thirds"), but remaining limitations are common. The diagnosis is clinically possible according to the "Budapest criteria". Additional examinations are possible in case of doubt but are neither conclusive nor exclusive. Corticoids and bisphosphonates are used alongside drugs that have an effect on neuropathic pain. Invasive therapies do not have good evidence and have therefore lost their importance. The rehabilitative therapy is carried out actively and with a lot of self-exercises at an early stage. Invasive anesthetic, passive therapies are obsolete. Special forms of treatment are "graded exposure" (GEXP) in the case of dominant anxiety and, e.g., "graded motor imagery" (GMI) in case of neglect-like symptoms. In addition to educational and behavioral therapy elements, psychotherapy for CRPS also includes participation as part of graded exposure.

Beyond type III Paprosky acetabular defects: are partial pelvic replacements with iliosacral fixation successful?

PURPOSE: Supra-acetabular bone loss close beyond the sciatic notch is one of the most challenging defect types for stable anatomical reconstruction in revision arthroplasty. Using reconstruction strategies from tumour orthopaedic surgery, we adapted tricortical trans-iliosacral fixation options for custom-made implants in revision arthroplasty. The aim of the present study was to present the clinical and radiological results of this extraordinary pelvic defect reconstruction. METHODS: Between 2016 and 2021, 10 patients with a custom-made pelvic construct using tricortical iliosacral fixation (see Fig. 1) were included in the study. Follow-up was 34 (SD 10; range 15-49) months. Postoperatively CT scans evaluating the implant position were performed. Functional outcome and the clinical results were recorded. RESULTS: Implantation was possible as planned in all cases in 236 (SD 64: range 170-378) min. Correct centre of rotation (COR) reconstruction was possible in nine cases. One sacrum screw crossed a neuroforamen in one case without clinical symptoms. During the follow-up period, four further operations were required in two patients. There were no individual implant revisions or aseptic loosening recorded. The Harris Hip Score increased significantly from 27 Pts. to 67 Pts. with a mean improvement of 37 (p < 0.005). EQ-5D developed from 0.562 to 0.725 (p = 0.038) as a clear improvement in quality of life. CONCLUSION: Custom-made partial pelvis replacement with iliosacral fixation offers a safe solution in "beyond Paprosky type III defects" for hip revision arthroplasty. Due to meticulous planning, precise implantation with good clinical outcome can be achieved. Furthermore, the functional outcome and patient satisfaction increased significantly showing promising early results with a relatively low complication rate.

Cortical Desmoid of the Distal Femur-Incidentaloma or Insertional Tendinopathy?

BACKGROUND: The cortical desmoid (DFCI) of the posteromedial femoral condyle is considered an asymptomatic incidental finding in adolescents without clinical relevance. The aim of this study was to evaluate the clinical relevance of DFCI from both a tumor orthopedic and sports medicine point of view. METHODS: n = 23 patients (13.74 ± 2.74 years; nineteen female, four male) with DFCI of the posteromedial femoral condyle were included. A localized posteromedial knee pain on exertion was differentiated from non-specific knee pain. Symptom duration, additional pathologies, number of MRIs, sports activity and training intensity, downtime, therapeutic modalities, and relief/remission of symptoms were documented. The Tegner activity scale (TAS) and Lysholm score (LS) were collected. The influence of specific posteromedial pain, MRI presence of paratendinous cysts, sports level as well as physiotherapy on downtime and LS/TAS was statistically analyzed. RESULTS: 100% reported knee symptoms at initial presentation. A localized posteromedial pain was documented in 52%. In 16/23 (70%) additional functional pathologies were diagnosed. Patients were physically highly active with high training intensities (6.52 ± 5.87 h/week) and performance level (65% competitive vs. 35% recreational). Patients underwent 1.91 ± 0.97 MRIs (max four). Symptom duration was 10.48 ± 11.02 weeks. A follow-up examination was performed after 12.62 ± 10.41 months (n = two lost to follow-up). 17/21 had physiotherapy, on average 17.06 ± 13.33 units. Overall downtime was 13.39 ± 12.50 weeks, the return-to-sports (RTS) rate 81%. 100%/38% reported a relief/remission of complaints. LS was 93.29 ± 7.95, median TAS before onset of knee complaints/at follow-up 7 (6-7)/7 (5-7). Specific posteromedial pain, presence of paratendinous cysts, sports level and physiotherapy had no significant influence on downtime and outcome parameters (n.s.). CONCLUSIONS: DFCI as a pathognomonic finding is recurrently encountered in the MRIs of children and adolescents. This knowledge is essential to spare patients from overtreatment. Contrary to the literature, the present results implicate a clinical relevance of DFCI particularly in those who are physically highly active with localized pain on exertion. Structured physiotherapy as basic treatment is recommended.

Cage subsidence-A multifactorial matter!

STUDY DESIGN: Retrospective cohort study OBJECTIVE: Wider cages are associated with improved decompression and reduced subsidence, but variation in cage physical properties limits consistent outcome analysis after thoracolumbar interbody fusion. This study investigated cage subsidence and its relationship to lateral and posterior approaches with a focus on the hypothesis that the larger surface area of lateral cages results in lower subsidence rates. METHODS: This study retrospectively reviewed 194 patients who underwent interbody fusion between 2016 and 2019 with a primary outcome of cage subsidence. Secondary outcomes were cage distribution (patients, approaches, expandability), cage dimensions, t­scores, length of hospital stay, blood loss, surgical time, and pelvic incidence-lumbar lordosis (PI-LL) mismatch. RESULTS: Medical records were reviewed for 194 patients receiving 387 cages at 379 disc levels. Subsidence was identified in 35.1% of lateral cages, 40.9% of posterior cages, and 36.3% of all cages. Lower surface area (p = 0.008) and cage expandability were associated with subsidence risk. Lower anteroposterior cage length proved to be a significant factor in the subsidence of posteriorly placed cages (p = 0.007). Osteopenic and osteoporotic patients experienced cage subsidence 36.8% of the time compared to 3.5% of patients with normal t­scores (p = 0.001). Cage subsidence correlated with postoperative deterioration of the PI-LL mismatch (p = 0.03). Patients receiving fusion augmentation with bone morphogenic protein experienced higher fusion rates (p < 0.01). CONCLUSION: Cage subsidence is a common complication that can significantly impact operative outcomes following thoracolumbar interbody fusion. Low t­scores, smaller surface area, cage expandability, and lower cage length in posterior approaches contribute significantly to cage subsidence.

Assessment of Complication Risk in the Treatment of Proximal Humerus Fractures: A Retrospective Analysis of 4019 Patients.

(1) Background: The treatment of proximal humeral fractures (PHFs) is debated controversially. Current clinical knowledge is mainly based on small single-center cohorts. The goal of this study was to evaluate the predictability of risk factors for complications after the treatment of a PHF in a large clinical cohort in a multicentric setting. (2) Methods: Clinical data of 4019 patients with PHFs were retrospectively collected from 9 participating hospitals. Risk factors for local complications of the affected shoulder were assessed using bi- and multivariate analyses. (3) Results: Fracture complexity with n = 3 or more fragments, cigarette smoking, age over 65 years, and female sex were identified as predictable individual risk factors for local complications after surgical therapy as well as the combination of female sex and smoking and the combination of age 65 years or older and ASA class 2 or higher. (4) Conclusion: Humeral head preserving reconstructive surgical therapy should critically be evaluated for patients with the risk factors abovementioned.

Brace-Free Rehabilitation after Isolated Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Autograft Is Not Inferior to Brace-Based Rehabilitation-A Randomised Controlled Trial.

PURPOSE: The postoperative use of a rehabilitative knee brace after isolated primary anterior cruciate ligament (ACL) reconstruction (ACLR) using a hamstring tendon (HT) autograft is controversial. A knee brace may provide subjective safety but can cause damage if applied incorrectly. The aim of this study is to evaluate the effect of a knee brace on clinical outcomes following isolated ACLR using HT autograft. METHODS: In this prospective randomised trial, 114 adults (32.4 ± 11.5 years, 35.1% women) underwent isolated ACLR using HT autograft after primary ACL rupture. Patients were randomly assigned to wear either a knee brace (n = 58) or no brace (n = 56) for 6 weeks postoperatively. An initial examination was performed preoperatively, and at 6 weeks and 4, 6, and 12 months. The primary endpoint was the subjective International Knee Documentation Committee (IKDC) score to measure participants' subjective perceptions. Secondary endpoints included objective knee function assessed by IKDC, instrumented knee laxity measurements, isokinetic strength tests of the knee extensors and flexors, Lysholm Knee Score, Tegner Activity Score, Anterior Cruciate Ligament-Return to Sport after Injury Score, and quality of life determined by Short Form-36 (SF36). RESULTS: There were no statistically significant or clinically meaningful differences in IKDC scores between the two study groups (3.29, 95% confidence interval (CI) -1.39 to 7.97, p = 0.03 for evidence of non-inferiority of brace-free compared with brace-based rehabilitation). The difference in Lysholm score was 3.20 (95% CI -2.47 to 8.87); the difference in SF36 physical component score 0.09 (95% CI -1.93 to 3.03). In addition, isokinetic testing did not reveal any clinically relevant differences between the groups (n.s.). CONCLUSIONS: Brace-free rehabilitation is non-inferior to a brace-based protocol regarding physical recovery 1 year after isolated ACLR using HT autograft. Consequently, the use of a knee brace might be avoided after such a procedure. LEVEL OF EVIDENCE: Level I, therapeutic study.

Safety and Feasibility of Robot-assisted Gait Training in Adults with Cerebral Palsy in an Inpatient Setting - an Observational Study.

BACKGROUND: To investigate the safety and feasibility of six sessions of Hybrid Assistive Limb (HAL) robot-assisted gait training (RAGT) integrated into an inpatient therapy concept and their influence on walking speed and gait parameters in adult CP patients. METHODS: Eleven subjects (male = 8, female = 3, mean age: 23 years and 2 months, ± 4.5 years) with spastic CP underwent six 20-minute RAGT sessions with the HAL during an 11-day hospital stay. Additionally, physiotherapy, physician-performed manual medicine, massage and exercise therapy were provided. Pre- (T1) and post- (T2) intervention assessments were: 10-metre walking test (10MWT), 6-minute walking test (6MWT), Gross Motor Function Measure (GMFM-88) and lower extremities passive range of motion (pROM). RESULTS: All subjects completed the study. No adverse events were noted. Walking speed in the 10MWT test increased from 32.5 s (± 24.5 s) at T1 to 27.5 s (± 21.4 s) at T2, without significance. Slight, but non-significant improvements were detected in the 6MWT, GMFM and pROM. Confounding factors did not significantly affect the results. Conclusion: Intensive therapy including HAL training leads to non-significant improvements. Further studies with more patients and longer intervention time could provide further insights into the RAGT therapy of adult patients with CP. Registration DRKS-ID: DRKS00020275.

Increased UHMWPE Particle-Induced Osteolysis in Fetuin-A-Deficient Mice.

Particle-induced osteolysis is a major cause of aseptic prosthetic loosening. Implant wear particles stimulate tissue macrophages inducing an aseptic inflammatory reaction, which ultimately results in bone loss. Fetuin-A is a key regulator of calcified matrix metabolism and an acute phase protein. We studied the influence of fetuin-A on particle-induced osteolysis in an established mouse model using fetuin-A-deficient mice. Ten fetuin-A-deficient (Ahsg−/−) mice and ten wild-type animals (Ahsg+/+) were assigned to test group receiving ultra-high molecular weight polyethylene (UHMWPE) particle implantation or to control group (sham surgery). After 14 days, bone metabolism parameters RANKL, osteoprotegerin (OPG), osteocalcin (OC), alkaline phosphatase (ALP), calcium, phosphate, and desoxypyridinoline (DPD) were examined. Bone volume was determined by microcomputed tomography (µCT); osteolytic regions and osteoclasts were histomorphometrically analyzed. After particle treatment, bone resorption was significantly increased in Ahsg−/− mice compared with corresponding Ahsg+/+ wild-type mice (p = 0.007). Eroded surface areas in Ahsg−/− mice were significantly increased (p = 0.002) compared with Ahsg+/+ mice, as well as the number of osteoclasts compared with control (p = 0.039). Fetuin-A deficiency revealed increased OPG (p = 0.002), and decreased levels of DPD (p = 0.038), OC (p = 0.036), ALP (p < 0.001), and Ca (p = 0.001) compared with wild-type animals. Under osteolytic conditions in Ahsg−/− mice, OPG was increased (p = 0.013), ALP (p = 0.015) and DPD (p = 0.012) were decreased compared with the Ahsg+/+ group. Osteolytic conditions lead to greater bone loss in fetuin-A-deficient mice compared with wild-type mice. Reduced fetuin-A serum levels may be a risk factor for particle-induced osteolysis while the protective effect of fetuin-A might be a future pathway for prophylaxis and treatment.

Antibody responses elicited by mRNA vaccination in firefighters persist six months and correlate inversely with age and directly with BMI.

Knowledge regarding the sustainability of immune responses after COVID-19 vaccination is important, e.g., to decide whom and when to booster. Thus, we analyzed antibody titers in firefighters six months after vaccination with the mRNA-based vaccine Comirnaty. SARS-CoV-2 spike-binding antibodies (bAb) were quantified and compared to peak responses determined in healthcare workers (HCW). For the firefighters, neutralizing antibodies (nAb) were also analyzed. Six months after the second vaccine dose, all analyzed firefighters had detectable bAb, and 91% exhibited nAb titers above 1:16. However, actual titers six months after vaccination were over 12-fold lower than in the HCW control group four weeks after vaccination. bAb and nAb responses showed a significant correlation, and age correlated inversely with antibody responses. Unexpectedly, participants with a body mass index over 25 had higher neutralization titers after six months. All participants with very low neutralization titers were offered booster vaccination. The booster vaccination improved the extent and sustainability of antibody responses.

Complication rates following stand-alone lateral interbody fusion: a single institution series after 10 years of experience.

PURPOSE: This retrospective single institution study's goal was to analyze and report the complications from stand-alone lateral lumbar interbody fusions (LLIF). METHODS: This research was approved by the institutional review board (STUDY2021000113). We retrospectively reviewed the database of patients with adult degenerative spine deformity treated via LLIF at our institution between January 2016 and December 2020. RESULTS: Stand-alone LLIF was performed in 158 patients (145 XLIF, 13 OLIF; mean age 65 y.; 88 f., 70 m.). Mean surgical time was 85 min (± 24 min). Mean follow-up was 14 months (± 5 m). Surgical blood loss averaged 120 mL (± 187 mL) and the mean number of fused levels was 1.2 (± 0.4 levels). Overall complication rate was 19.6% (31 total; 23 approach-related, 8 secondary complications). CONCLUSION: Lateral interbody fusion appears to be a safe surgical intervention with relatively low complication- and revision rates.