Search

Background: The most common reason for lower-extremity amputations remains the management of complications of diabetes mellitus (DM) and/or peripheral vascular disease. Traditional socket prostheses remain the rehabilitation standard, although transcutaneous osseointegration for amputees (TOFA) is proving a viable alternative. Limited studies of TOFA for vascular amputees have been published, but no study has focused on TOFA for patients with DM, neglecting this important patient population. The primary aim of the present study exploring this potential care option was to report the frequencies and types of adverse events following TOFA for patients with well-controlled DM. The secondary aims were to report their mobility and quality-of-life changes., Methods: A retrospective review was performed of 17 consecutive patients with well-controlled DM who had undergone unilateral transfemoral TOFA from 2013 to 2019 and had been followed for at least 2 years. Outcomes were perioperative complications, additional surgery (soft-tissue refashioning, debridement, implant removal, periprosthetic fracture treatment), mobility (daily prosthesis wear hours, K-level, Timed Up and Go Test, 6-Minute Walk Test), and patient-reported outcomes (Questionnaire for Persons with a Transfemoral Amputation, Short Form-36)., Results: There were no perioperative systemic complications, deaths, or proximal amputations. Two patients (12%) sustained a periprosthetic fracture following a fall, managed by internal fixation with implant retention, and regained independent ambulation. Eight patients (47%) had additional surgery or surgeries for non-traumatic complications: 4 (24%) had soft-tissue refashioning, 3 (18%) had debridement, and 3 others had implant removal with subsequent revision osseointegration for aseptic loosening (1) or infection (2). The proportion of patients wearing their prosthesis at least 8 hours daily improved from 5 (36%) to 11 (79%) of 14 (p = 0.054). The proportion of patients who achieved at least K-level 2 improved from 6% to 94% (p < 0.001). Other changes were not significant., Conclusions: Contraindicating TOFA for all patients with DM seems draconian. Patients with well-controlled DM experienced significant mobility improvements, although additional surgery was somewhat common. Improvements in selection criteria or surgical technique to reduce risks are needed so that TOFA can be routinely considered for amputees with well-controlled DM., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: No external funding was received for this work. One of the authors holds the patent on the OPL implant. The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSOA/A720)., (Copyright © 2024 The Authors. Published by The Journal of Bone and Joint Surgery, Incorporated. All rights reserved.)

Background: Non-tuberculous mycobacteria (NTM) are rare causes of bone and joint infection (BJI) and there is limited evidence on which to base management decisions. This study describes 1 year of experience from a multi-disciplinary BJI team which collects data on all cases reviewed at a tertiary referral centre in Queensland, Australia., Methods: The database was interrogated for all cases in which NTM were recovered from operative samples. Individual chart review was performed to collect the details of each case., Results: A total of seven cases were managed between 1st February 2021 and 28th February 2022, comprising one patient with chronic osteomyelitis, three with fracture-related infections, two with prosthetic joint infections, and one with infection of a synthetic ligament graft. In contrast to pulmonary NTM infections, most patients were clinically well and immunocompetent, and most infections were propagated by direct inoculation. Time to diagnosis was unknown in three patients, with 1, 2, 2, and 5 months for the remaining four. Rapid growing NTM were diagnosed on routine cultures and specific mycobacterial cultures were confirmatory. Management was characterized by multiple stage surgical procedures and prolonged antimicrobial regimens., Conclusions: Antimicrobial complications were common; however, all patients were infection free at their latest follow up. Despite the inherent limitations, these results suggest that routinely ordering mycobacterial culture is of low yield. There is potential for shorter-term oral antimicrobial treatments. Prospective research is required to optimize treatment regimens and durations., (© 2024 The Author(s). ANZ Journal of Surgery published by John Wiley & Sons Australia, Ltd on behalf of Royal Australasian College of Surgeons.)

Background: Rotational malalignment after operative fracture treatment of the lower extremity may be associated with increased pain and functional impairment. Despite its clinical relevance, there are no uniform management guidelines. The aim of this scoping review is to provide an overview of all available evidence to diagnose and treat rotational deformities of the lower extremity following operative fracture treatment., Methods: This scoping review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A literature search was carried out on 22 August 2023 by two independent reviewers in the Pubmed (MEDLINE), Embase, Web of Science, and Cochrane library databases. The search strategy was developed with the assistance of a biomedical information specialist. The main search terms were tibial and femoral malrotations. Disagreements were resolved through discussion with a third reviewer., Results: After screening and quality assessment of 3929 unique identified records, 50 articles were included for qualitative synthesis. Most studies were retrospective case reports or case series. Thirty studies focused on the femur, 11 on the tibia and nine included both femur and tibia. Most of the included studies presented cases where malrotation was associated with other limb deformities. Only 18 studies focused solely on the treatment of malrotation of the lower extremities after operative fracture treatment. Regarding diagnosis, bilateral CT-scans were used in 34 studies. Regarding treatment, external fixation was used in two studies, internal fixation (either intramedullary nail or plate) in 45 studies, and in three studies the authors used both. Overall, revision surgery resulted in good clinical outcomes with low complication rates., Conclusion: This scoping review reveals that rotational malalignment following operative treatment of lower extremity fractures remains an important complication. Although it occurs frequently and is associated with severe disability for the patient, standardized guidelines regarding the terminology, diagnosis, indications for intervention and treatment are lacking. CT-scan is the most used diagnostic modality in daily clinical practice. Revision surgery, using diverse operative techniques, demonstrated positive results, significantly alleviating patient complaints with few complications. Nevertheless, an international consensus regarding the optimal management pathway is needed, and future prospective clinical studies seem therefore necessary., Competing Interests: Declaration of competing interest All authors declare no conflict of interest with respect to the preparation and writing of this article., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: To develop a quality appraisal tool for the assessment of cadaveric biomechanical laboratory and other basic science biomechanical studies., Methods: For item identification and development, a systematic review of the literature was performed. The content validity index (CVI) was used either to include or exclude items. The content validity ratio (CVR) was used to determine content validity. Weighting was performed by each panel member; the final weight was either up- or downgraded to the closest of 5% or 10%. Face validity was scored on a Likert scale ranked from 1 to 7. Test-retest reliability was determined using the Fleiss kappa coefficient. Internal consistency was assessed with Cronbach's alpha. Concurrent criterion validity was assessed against the Quality Appraisal for Cadaveric Studies scale., Results: The final Biomechanics Objective Basic science Quality Assessment Tool (BOBQAT) score included 15 items and was shown to be valid, reliable, and consistent. Five items had a CVI of 1.0; 10 items had a CVI of 0.875. For weighting, 5 items received a weight of 10%, and 10 items a weight of 5%. CVR was 1.0 for 6 items and 0.75 for 9 items. For face validity, all items achieved a score above 5. For test-retest reliability, almost-perfect test-retest reliability was observed for 10 items, substantial agreement for 4 items, and moderate agreement for 1 item. For internal consistency, Cronbach's alpha was calculated to be 0.71. For concurrent criterion validity, Pearson's product-moment correlation was 0.56 (95% confidence interval [CI] = 0.38-0.70, P = .0001)., Conclusions: Cadaveric biomechanical and laboratory research can be quantitatively scored for quality based on the inclusion of a clear and answerable purpose, demographics, specimen condition, appropriate bone density, reproducible technique, appropriate outcome measures, appropriate loading conditions, appropriate load magnitude, cyclic loading, sample size calculation, proper statistical analysis, results consistent with methods, limitations considered, conclusions based on results, and disclosure of funding and potential conflicts., Clinical Relevance: Study quality assessments are important to evaluate internal and external validity and reliability and to identify methodological flaws and misleading conclusions. The BOBQAT score will help not only in the critical appraisal of cadaveric biomechanical studies but also in guiding the designs of such research endeavors., Competing Interests: Disclosures The authors report no conflicts of interest in the authorship and publication of this article. Full ICMJE author disclosure forms are available for this article online, as supplementary material., (Copyright © 2024 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.)

Background: Some amputees with transfemoral osseointegration (TFOI) have ipsilateral hip arthritis which can be addressed with total hip arthroplasty (THA). This study reported the medium-term outcomes of THA in association with TFOI (THA + TFOI)., Methods: Retrospective review was performed for eight patients with THA + TFOI performed at least 2 years prior. Primary outcomes include complications prompting surgical intervention. Secondary outcomes include changes in mobility (K-level, 6-minute walk test [6MWT], timed up and go) and patient-reported measures (hip pain, daily prosthesis wear hours, Questionnaire for Persons with a Transfemoral Amputation, and Short Form 36 [SF36])., Results: One patient died after 11 months (cancer); he was included to maximally report complications but excluded from mobility and reported outcomes. Three patients required subsequent surgeries: Two had skin refashioning, and the other underwent hip debridement of the replaced joint with subsequent removal of the TFOI. No perioperative complications, fractures, or arthroplasty explantations occurred. All patients reported complete hip pain relief. Of 6 patients reporting prosthesis wear time, 2 (33%) wore their prosthetic leg at least 4 hours daily before, vs all (100%) who did afterward ( P  = .061). K-levels improved in all responding patients. All 5 wheelchair-bound patients achieved and maintained ambulation. The Questionnaire for Persons with a Transfemoral Amputation and Short Form 36 did not significantly change., Conclusions: THA + TFOI does not appear to pose an inevitable risk for prosthetic hip infection and may improve mobility and enhance quality of life (QOL) for transfemoral amputees with concurrent arthritic hip pain who are dissatisfied with their outcome following traditional socket prosthesis rehabilitation., (© 2024 The Authors.)

Background: Upper limb (UL) amputation is disabling. ULs are necessary for many domains of life 1 , and few effective motor and sensory replacements are accessible 2 . Approximately 41,000 people in the United States have UL amputation proximal to the fingers 3 , two-thirds of (all) traumatic amputations are UL 4 , and 80% of UL amputations are performed for trauma-related etiologies 5 . Socket prosthesis (SP) abandonment remains high because of the lack of sensation, limited prosthesis control, perceived weight, and difficulty comfortably wearing the SP 6 . Transcutaneous osseointegration 7,8 surgically inserts a bone-anchored implant, passed through a transcutaneous portal to attach a terminal device, improving amputee rehabilitation by reducing perceived weight, conferring osseoperception 9 , and increasing wear time 10 . Without the socket, all residual skin and musculature remain available for transcutaneous myoelectrodes. The present article describes single-stage radius and ulna press-fit osseointegration (PFOI) after trans-forearm amputation., Description: This technique resembles a lower-extremity PFOI 11,12 . Importantly, at-risk nerves and vessels are different, and implant impaction must be gentler as a result. The surgery is indicated for patients who are dissatisfied with SP rehabilitation or declining alternative rehabilitative options, and who are motivated and enabled to procure, train with, and utilize a forearm prosthesis. An engaged prosthetist is critical. Surgical steps are exposure, bone-end and canal preparation, first implant insertion (in the operative video shown, in the radius), purse-string muscle closure, confirmation that radius-ulna motion remains, performing the prior steps for the other bone (in the video, the ulna), and closure (including potential nerve reconstruction, soft-tissue contouring, and portal creation). Although the patient in the operative video did not require nerve procedures to address pain or to create targets for transcutaneous myoelectrodes, targeted muscle reinnervation or a regenerative peripheral nerve interface procedure could be performed following exposure., Alternatives: Alternatives include socket modification, bone lengthening and/or soft-tissue contouring 13 , Krukenberg-type reconstructions 14 , or accepting the situation. An alternative implant is a screw-type osseointegration implant. Our preference for press-fit implants is based on considerations such as our practice's 12-year history of >1,000 PFOI surgeries; that the screw-type implant requires sufficient cortical thickness for the threads 15 , which is compromised in some patients; the lower cost per implant; that the procedure is performed in 1 instead of 2 surgical episodes 15,16 ; and the documented suitability of press-fit implants for patients with challenging anatomy or comorbidities 17-19 ., Rationale: PFOI can be provided for amputees having difficulty with socket wear. PFOI usually provides superior prosthesis stability, which can confer better prosthesis control versus nonoperative and other operative options in patients expressing dissatisfaction for reasons such as those mentioned above, or for poor fit, compromised energy transfer, skin pinching, compression, and abrasions. For patients who want myoelectric control of their prosthesis but who are unable because the optimal myoelectric location is obstructed by the socket, osseointegration may provide access for the electrodes by eliminating the socket., Expected Outcomes: Only 3 trans-forearm osseointegration 20-22 publications totaling 10 limbs could be identified, limiting the ability to determine generalizable outcomes. Osseointegrated prostheses, being skeletally anchored, feel lighter to patients than SPs, which should confer better outcomes. In 1 patient, multiple implant fractures and infection prompted additional surgeries. Periprosthetic bone fractures and non-infectious loosening have not been documented for UL osseointegration., Important Tips: Osseointegration eliminates the socket, relieving socket-based pain. However, neurogenic pain relief requires specific nerve procedures.Osseointegration provides a prosthesis connection. Nerve- or muscle-based prosthesis control requires separate, potentially integrated planning.Osseointegrated prostheses confer osseoperception (i.e., mechanical force transmission), not "normal" skin-mediated afferent sensation (i.e., light touch, temperature, pain) or native proprioception.Prostheses must be individualized to the patient's elbow flexion and radioulnar rotation. An attentive prosthetist must be ensured preoperatively.Achieving the demonstrated outcomes requires more therapy and retraining than walking with an osseointegrated lower-extremity prosthesis. Patients must expect at least several months of spending multiple hours daily engaging in self-directed rehabilitation.Prosthesis utilization decision aids 23 may minimize non-beneficial surgeries., Acronyms and Abbreviations: UL = upper limbSP = socket prosthesisPFOI = press-fit osseointegrationperi-pros fx = periprosthetic fractureMRI = magnetic resonance imagingCT = computed tomography., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSEST/A449)., (Copyright © 2024 The Authors. Published by The Journal of Bone and Joint Surgery, Incorporated. All rights reserved.)

Importance: Most patients use a traditional socket prosthesis (TSP) to ambulate independently following transtibial amputation. However, these patients generally require prosthesis repairs more than twice annually and an entirely new prosthesis every two years. Furthermore, transtibial amputation patients have four times the skin ulceration rate of transfemoral patients, prompting more frequent prosthesis refitting and diminished use. Trans-Tibial osseointegration (TTOI) is a promising technique to address the limitations of TSP, but remains understudied with only four cohorts totaling 41 total procedures reported previously. Continued concerns regarding the risk of infection and questions as to functional capacity postoperatively have slowed adoption of TTOI worldwide., Objective: This study reports the changes in mobility, quality of life (QOL), and the safety profile of the largest described cohort of patients with unilateral TTOI following traumatic amputation., Design: Retrospective observational cohort study. The cohort consisted of patients with data outcomes collected before and after osseointegration intervention., Setting: A large, tertiary referral, major metropolitan center., Participants: Twenty-one skeletally mature adults who had failed socket prosthesis rehabilitation, with at least two years of post-osseointegration follow-up., Main Outcomes and Measures: Mobility was evaluated by K-level, Timed Up and Go (TUG), and Six Minute Walk Test (6MWT). QOL was assessed by survey: daily prosthesis wear hours, prosthesis problem experience, general contentment with prosthesis, and Short Form 36 (SF36). Adverse events included any relevant unplanned surgery such as for infection, fracture, implant loosening, or implant failure., Results: All patients demonstrated statistically significant improvement post osseointegration surgery with respect to K-level, TUG, 6MWT, prosthesis wear hours, prosthesis problem experience, general prosthesis contentment score, and SF36 Physical Component Score (p < 0.01 for all). Three patients had four unplanned surgeries: two soft tissue refashionings, and one soft tissue debridement followed eventually by implant removal. No deaths, postoperative systemic complications, more proximal amputations, or periprosthetic fractures occurred., Conclusions and Relevance: TTOI is likely to confer mobility and QOL improvements to patients dissatisfied with TSP rehabilitation following unilateral traumatic transtibial amputation. Adverse events are relatively infrequent and not further disabling. Judicious use of TTOI seems reasonable for properly selected patients., Level of Evidence: 2 (Therapeutic investigation, Observational study with dramatic effect)., Competing Interests: Declaration of competing interest 1) Munjed Al Muderis: Receives royalties, stock or stock options, and is a paid consultant for Osseointegration International Ltd, which makes implants discussed in this manuscript. 2) Yao Chang Tan: was formerly an employee of Osseointegration International Ltd, which makes implants discussed in this manuscript. 3) William Lu: is an employee of Osseointegration International Ltd, which makes implants discussed in this manuscript., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Objective: Mechanical alignment of the lower limbs has been suggested to cause abnormal uneven loading across the compartments at the knee, but its contribution to the initiation and progression of arthritis remains controversial. This study aimed to establish whether malalignment of the lower limb after trauma is associated with worsened arthritis scores in the theoretically overloaded compartment, and if arthritis scores continuously correlate with the degree of malalignment and time with deformity., Design: After screening 1160 X-rays, 60 patients were identified with long-leg radiographs > 2 years after fracture. Measurement of mechanical axis deviation (MAD) divided into groups of varus malalignment ( n = 16, >16 mm), valgus ( n = 25, <0 mm), and normal alignment ( n = 19). Alignment and bilateral knee compartmental arthritis scores were recorded by three clinicians, compared via analysis of variance and assessed with linear regression against time since injury using MAD as a covariate., Results: In varus and valgus malalignment, there was a greater mean arthritis score in the "overloaded" compartment compared to the contralateral side, with varus medial Osteoarthritis Research Society International (OARSI) scores 5.17 ± 2.91 vs 3.50 ± 2.72 ( P = 0.006) and Kellegren-Lawrence scores 2.65 ± 1.19 vs 1.79 ± 1.24 ( P ≤ 0.001). In a linear regression model, OARSI arthritis score was significantly associated with absolute MAD (0.6/10 mm MAD, P < 0.001) and time (0.7/decade, P ≤ 0.001)., Conclusions: Malalignment consistently results in more advanced arthritis scores in the overloaded compartment, most likely related to abnormal loading across the knee. Severity of arthritis using OARSI grading continuously correlates with degree of malalignment and time with deformity after post-traumatic malunion., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Transcutaneous osseointegration for amputees (TOFA) is an evolving technology that has the potential to revolutionize the interface between the amputee and their prosthesis, showing potential at many levels of amputation. While no amputation is without its challenges, TOFA requires a highly specialized prosthesis and a multidisciplinary team that includes specialized surgeons, physical therapists, wound care teams, and social workers who guide the amputee through surgery, postoperative rehabilitation, and the chronic wound care that goes into maintaining the prosthesis. The infrastructure required to facilitate care pathways that lead to reliable, successful outcomes are unique in each health care setting, including those in advanced health care systems such as the United States and Australia. This article details the emerging evidence supporting the use of this prosthetic interface design and many of the challenges that providers face when establishing programs to offer this type of care in the United States., Competing Interests: No conflict of interest for all authors, and no funding received., (Copyright © 2024 The Authors. Published by Wolters Kluwer Health, Inc. on behalf of the Orthopaedic Trauma Association.)

Background: The options available to salvage a failed total knee replacement (TKR) include transfemoral amputation (TFA) and knee arthrodesis (KA). This systematic review aims to evaluate outcomes following either TFA or KA, comparing ambulatory status, additional subsequent surgery, postoperative infection, pain, health-related quality of life (HRQoL), and mortality rate., Methods: A literature search was conducted in EMBASE, Ovid Medline, and PubMed. Only primary research studies were included and data were independently extracted using a standardized form. The methodological quality of the studies was evaluated using Newcastle-Ottawa Scale., Results: Forty-four papers were included, comprising 470 TFA and 1034 KA patients. The methodological quality of the studies was moderate. No TFA versus KA randomized controlled trials could be identified. Pooled data totals via subgroup analyses were performed, owing to inconsistent reporting methods in the included studies. Prosthesis use rate by TFA patients was 157/316 = 49.7%. Significant differences included that TFA patients had lower rates of ambulatory capacity than KA patients (139/294 = 45.6% versus 248/287 = 86.4%, p < 0.001), TFA ambulators were less likely to use an ambulatory aid (55/135 = 40.7% versus 167/232 = 72.0%, p < 0.001), and TFA was associated with a greater postoperative infection rate than KA (29/118 = 24.6% versus 129/650 = 17.2%, p = 0.054). There was a similar rate of revision surgery between TFA and KA (37/183 = 20.2% versus 145/780 = 18.6%, p = 0.612). Data on HRQoL for both TFA and KA were limited, contradictory, and heterogeneous., Conclusion: No randomized controlled trials comparing TFA versus KA exist;therefore, current data likely reflects substantial selection bias. The currently available evidence suggests that KA patients are significantly more likely to achieve independent bipedal ambulation than TFA patients. In both treatment cohorts, subsequent infection and revision surgery remain a relatively common occurrence., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Crown Copyright © 2023. Published by Elsevier B.V. All rights reserved.)

Introduction : Transcutaneous osseointegration following amputation (TOFA) confers better mobility and quality of life for most patients versus socket prosthesis rehabilitation. Peri-TOFA infection remains the most frequent complication and lacks an evidence-based diagnostic algorithm. This study's objective was to investigate preoperative factors associated with positive intraoperative cultures among patients suspected of having peri-TOFA infection in order to create an evidence-based diagnostic algorithm. Methods : We conducted a retrospective study of 83 surgeries (70 patients) performed to manage suspected lower-extremity peri-TOFA infection at a specialty orthopedic practice and tertiary referral hospital in a major urban center. The diagnosis of infection was defined as positive intraoperative cultures. Preoperative patient history (fevers, subjective pain, increased drainage), physician examination findings (local cellulitis, purulent discharge, implant looseness), and laboratory data (white blood cell count, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and external swab culture) were evaluated for association with subsequent positive intraoperative cultures using regression and area under receiver-operator curve (AUC) modeling. Results : Peri-implant limb pain (highly correlated with infection), ESR > 30 (highly correlated against infection), positive preoperative swab (moderately correlated with infection), gross implant motion (moderately correlated against infection), and erythema or cellulitis of the transcutaneous region (mildly correlated with infection) were variables included in the best AUC model, which achieved an 85 % positive predictive value. Other clinical findings and laboratory values (notably CRP and WBC) were non-predictive of infection. Conclusions : This seminal investigation to develop a preoperative diagnostic algorithm for peri-TOFA infection suggests that the clinical examination remains paramount. Further evaluation of a wider spectrum of clinical, laboratory, and imaging data, consistently and routinely collected with prospective data techniques in larger cohorts of patients, is necessary to create a robust predictive algorithm., Competing Interests: Munjed Al Muderis is the sole beneficiary of Osseointegration Holdings Pty Ltd (OH) and Osseointegration International Pty Ltd (OI). OI exclusively distributes the OPL implant system worldwide. OH owns the rights and patents to the OPL implant system. All other authors have no competing interests., (Copyright: © 2024 Shafaf Hasin Alam et al.)

Almost all prior mouse fracture healing models have used needles or K-wires for fixation, unwittingly providing inadequate mechanical stability during the healing process. Our contention is that the reported outcomes have predominantly reflected this instability, rather than the impact of diverse biological conditions, pharmacologic interventions, exogenous growth factors, or genetic considerations. This important issue becomes obvious upon a critical review of the literature. Therefore, the primary aim of this study was to demonstrate the significance of mouse-specific implants designed to provide both axial and torsional stability (Screw and IM Nail) compared to conventional pins (Needle and K-wires), even when used in mice with differently sized marrow canals and diverse genetic backgrounds. B6 (large medullary canal), DBA, and C3H (smaller medullary canals) mice were employed, all of which have different bone morphologies. Closed femoral fractures were created and stabilized with intramedullary implants that provide different mechanical conditions during the healing process. The most important finding of this study was that appropriately designed mouse-specific implants, providing both axial and torsional stability, had the greatest influence on bone healing outcomes regardless of the different bone morphologies encountered. For instance, unstable implants in the B6 strain (largest medullary canal) resulted in significantly greater callus, with a fracture region mainly comprising trabecular bone along with the presence of cartilage 28 days after surgery. The DBA and C3H strains (with smaller medullary canals) instead formed significantly less callus, and only had a small amount of intracortical trabeculation remaining. Moreover, with more stable fracture fixation a higher BV/TV was observed and cortices were largely restored to their original dimensions and structure, indicating an accelerated healing and remodeling process. These observations reveal that the diaphyseal cortical thickness, influenced by the genetic background of each strain, played a pivotal role in determining the amount of bone formation in response to the fracture. These findings are highly important, indicating the rate and type of tissue formed is a direct result of mechanical instability, and this most likely would mask the true contribution of the tested genes, genetic backgrounds, or various therapeutic agents administered during the bone healing process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Objectives: Distal femur fractures can exhibit extensive comminution, and open fractures may result in bone loss. These injuries are under high mechanical demands when stabilized with a lateral locked plate (LLP), and are at risk of non-union or implant failure. This study investigates the optimal LLP screw configuration for distal femur fractures with a large metadiaphyseal gap of 5 cm., Methods: A finite element (FE) model, validated against experimentally measured strains and displacement, evaluated pull-out forces and stress concentration on typical implants under clinical conditions corresponding with the 10 % point during the stance phase of the gait cycle., Results: Maximum stress was up to 83 % less when the ratio (Cp) between the proximal screw-distribution-length and the distance of the first screw to the fracture was less than 0.2; maximum pull-out force was 99 % less when this ratio was higher than 0.4., Conclusions: Screw configuration based on either normal or osteopenic bone quality plays an important role in determining the risk of construct failure for a major (50 mm) distal femoral metadiaphyseal segmental defect. This study provides valuable information when planning definitive fixation for distal femur fractures with extensive comminution or segmental bone defects, to mitigate the risk of implant failure and subsequent nonunion., Competing Interests: Declaration of Competing Interest The authors declare that they have no financial or personal relationships that could inappropriately influence or bias their work, including but not limited to employment, consultancies, stock ownership, honoraria, paid expert testimony, patent applications/registrations, and grants or other funding., (Copyright © 2023. Published by Elsevier Ltd.)

Aims: The aim of this study was to perform the first population-based description of the epidemiological and health economic burden of fracture-related infection (FRI)., Methods: This is a retrospective cohort study of operatively managed orthopaedic trauma patients from 1 January 2007 to 31 December 2016, performed in Queensland, Australia. Record linkage was used to develop a person-centric, population-based dataset incorporating routinely collected administrative, clinical, and health economic information. The FRI group consisted of patients with International Classification of Disease 10th Revision diagnosis codes for deep infection associated with an implanted device within two years following surgery, while all others were deemed not infected. Demographic and clinical variables, as well as healthcare utilization costs, were compared., Results: There were 111,402 patients operatively managed for orthopaedic trauma, with 2,775 of these (2.5%) complicated by FRI. The development of FRI had a statistically significant association with older age, male sex, residing in rural/remote areas, Aboriginal or Torres Strait Islander background, lower socioeconomic status, road traffic accident, work-related injuries, open fractures, anatomical region (lower limb, spine, pelvis), high injury severity, requiring soft-tissue coverage, and medical comorbidities (univariate analysis). Patients with FRI had an eight-times longer median inpatient length of stay (24 days vs 3 days), and a 2.8-times higher mean estimated inpatient hospitalization cost (AU$56,565 vs AU$19,773) compared with uninfected patients. The total estimated inpatient cost of the FRI cohort to the healthcare system was AU$156.9 million over the ten-year period., Conclusion: The results of this study advocate for improvements in trauma care and infection management, address social determinants of health, and highlight the upside potential to improve prevention and treatment strategies., Competing Interests: The authors have no financial conflicts of interest to declare. R. Crawford reports personal royalties or licenses from Stryker, unrelated to this study. K. Testworth reports consulting fees from the AO Foundation, Smith & Nephew, and Johnson and Johnson, payment or honoraria for lectures, presentations, speakers bureaus, manuscript writing or educational events from Hereus and Smith & Nephew, support for attending meetings and/or travel from the AO Foundation, and stock or stock options from OrthoDx and BioConsultancy, all of which are unrelated to this study. K. Tetsworth is also President of the Australian Limb Reconstruction Society and a member of the OTA International Relations Committee. A. Foster reports funding from Queensland University of Technology for the article processing charges., (© 2024 Foster et al.)