Different microbial and resistance patterns in primary total knee arthroplasty infections - a report on 283 patients from Lithuania and Sweden.

BACKGROUND: The microbiology and the susceptibility patterns of infected total knee arthroplasties (TKAs) vary depending on demographic, local antimicrobial stewardship, and surgical factors. We wanted to compare the recent microbial profile and antimicrobial resistance pattern in revisions due to infections after primary TKAs in Sweden and Lithuania. Our hypothesis was that there is a difference in bacteriology and resistance pattern based on patient related, societal and local hospital factors as almost similar praxis have been applied for TKA surgery, short term systemic prophylaxis and routine use of local gentamicin containing bone cement. METHODS: Primary TKAs revised for the first time due to verified or suspected infection were collected nationwide in Sweden during 2018, and in Lithuania between 2011 and 2020 from a single major TKA revision centre in Kaunas. We identified 202 TKAs in Sweden from the Swedish Knee Arthroplasty Register and 84 from Kaunas revised due to infection. We collected available culture reports and evaluated the type of microorganisms with antimicrobial resistance pattern at revision. RESULTS: The majority of the infected cases in Sweden were early-type prosthetic joint infection (PJI) (44%), whereas late-type PJI (52%) were more common in the Kaunas cases. Gram-positive bacteria prevailed in both Sweden (55%) and Lithuania (80%). Staphylococcus aureus was the most frequent organism identified in both countries (33% in Sweden and 34% in Lithuania). More polymicrobial infections were observed in Sweden than in Lithuania (16 and 6% respectively). Methicillin resistance in Staphylococcus aureus and coagulase-negative staphylococci were higher in Lithuania (4/28 and 19/29) than in Sweden (1/42 and 9/41). CONCLUSIONS: The type of infections, microbial profile, and drug resistance pattern differed between Sweden and Lithuania. Societal and local hospitals factors with emerging resistance in Lithuania are the most plausible explanation for the difference. Lack of complete data on a national level in Lithuania underlines the importance of adding microbiology of PJIs in implant registers for national aggregation and allow cross country comparisons.

Synthetic hydroxyapatite: a recruiting platform for biologically active molecules.

Background and purpose - Targeted delivery of drugs is important to achieve efficient local concentrations and reduce systemic side effects. We hypothesized that locally implanted synthetic hydroxyapatite (HA) particles can act as a recruiting moiety for systemically administered drugs, leading to targeted drug accretion.Methods - Synthetic HA particles were implanted ectopically in a muscle pouch in rats, and the binding of systemically circulating drugs such as zoledronic acid (ZA), tetracycline and 18F-fluoride (18F) was studied. The local biological effect was verified in an implant integration model in rats, wherein a hollow implant was filled with synthetic HA particles and the animals were given systemic ZA, 2-weeks post-implantation. The effect of HA particle size on drug binding and the possibility of reloading HA particles were also evaluated in the muscle pouch.Results - The systemically administered biomolecules (ZA, tetracycline and 18F) all sought the HA moiety placed in the muscle pouch. Statistically significant higher peri-implant bone volume and peak force were observed in the implant containing HA particles compared with the empty implant. After a single injection of ZA at 2 weeks, micro HA particles showed a tendency to accumulate more 14C-zoledronic acid (14C-ZA) than nano-HA particles in the muscle pouch. HA particles could be reloaded when ZA was given again at 4 weeks, showing increased 14C-ZA accretion by 73% in microparticles and 77% in nanoparticles.Interpretation - We describe a novel method of systemic drug loading resulting in targeted accretion in locally implanted particulate HA, thereby biologically activating the material.

Intermediate-Term Outcome After Distal Radius Fracture in Patients With Poor Outcome at 1 Year: A Register Study With a 2- to 12-Year Follow-Up.

PURPOSE: Most patients recover well from a distal radius fracture (DRF). However, approximately one-fifth have severe disability after 1 year when evaluated using the Disabilities of the Arm, Shoulder, and Hand (DASH) questionnaire. In the present study, we evaluated this subgroup of patients in our register with an inferior outcome. We hypothesized that the patient-reported outcome would improve with time. METHODS: Since 2001, patients 18 years and older with a DRF, at the Department of Orthopedics, Skåne University Hospital (Lund, Sweden) are prospectively registered in the Lund Wrist Fracture Register. We have previously defined a DASH score above 35 at the 1-year follow-up as the cutoff of major disability. Between 2003 and 2012, 17% of the patients (445 of 2,571) in the register exceeded this cutoff. Three hundred eighty-eight were women and 57 men and the mean age was 69 years (range, 18-95 years). One-fourth had been surgically treated. In December 2014, 2 to 12 years after the fracture, a follow-up DASH questionnaire was sent to the 346 of 445 patients still alive. RESULTS: Seventy-three patients (27%) had initially been treated surgically and 196 (73%) nonsurgically for their DRF. Two hundred sixty-nine of 346 patients (78%) returned the follow-up DASH questionnaire at 2 to 12 years (mean, 5.5 years) after the fracture. The overall median DASH score improved from 50 at 1 year to 36 at the 2- to 12-year follow-up, (P < .05). Forty-seven percent had improved to a score below the cutoff 35, but 53% remained at a high suboptimal level. CONCLUSIONS: The subjective outcome after a DRF improves over time for patients with an inferior result at 1 year, but more than half of the patients continue to have major disability. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Decreased migration with locally administered bisphosphonate in cemented cup revisions using impaction bone grafting technique.

Background and purpose - Impaction bone grafting (IBG) in revision hip surgery is an established method in restoring bone stock deficiencies. We hypothesized that local treatment of the morsellized allograft with a bisphosphonate in cemented revision would, in addition to increased bone density, also reduce the early migration of the cup as measured by radiostereometry (RSA). Patients and methods - 20 patients with aseptic cup loosening underwent revision using the IBG technique. The patients were randomized to either clodronate (10 patients) or saline (10 patients, control group) as local adjunct to the morsellized bone. The outcome was evaluated by dual-energy X-ray absorptiometry (DXA) during the first year regarding periacetabular bone density and with radiostereometric analysis (RSA) for the first 2 years regarding cup migration. Results - 2 patients were lost to follow-up: 9 patients remained in the clodronate and 9 in the control group. Less proximal migration was found in the clodronate group compared with the controls, measured both over time (mixed-models analysis, p = 0.02) as well as at the specified time points up to 2 years (0.22 mm and 0.59 mm respectively, p = 0.02). Both groups seemed to have stabilized at 1 year. We found similar bone mineral density measured by DXA, and similar RSA migration in the other directions. No cups were re-revised. Interpretation - Local treatment of the allograft bone with clodronate reduced early proximal migration of the revised cup but without any measurable difference in periacetabular bone density.

Fragment-Specific Fixation Versus Volar Locking Plates in Primarily Nonreducible or Secondarily Redisplaced Distal Radius Fractures: A Randomized Controlled Study.

PURPOSE: To compare the patient-reported, clinical, and radiographic outcome of 2 methods of internal fixation in distal radius fractures. METHODS: Fifty patients, mean age 56 years (range, 21-69 years) with primarily nonreducible or secondarily redisplaced distal radius fractures were randomized to open reduction internal fixation using volar locking plates (n = 25) or fragment-specific fixation (n = 25). The patients were assessed on grip strength, range of motion, patient-reported outcome (Quick Disabilities of the Arm, Shoulder, and Hand), pain (visual analog scale), health-related quality of life (Short Form-12 [SF-12]), and radiographic evaluation. Grip strength at 12 months was the primary outcome measure. RESULTS: At 12 months, no difference was found in grip strength, which was 90% of the uninjured side in the volar plate group and 87% in the fragment-specific fixation group. No differences were found in range of motion and the median Quick Disabilities of the Arm, Shoulder, and Hand score was 5 in both groups. The overall complication rate was significant, 21% in the volar locking plate group, compared with 52% in the fragment-specific group. CONCLUSIONS: In treatment of primarily nonreducible or secondarily redisplaced distal radius fractures, volar locking plates and fragment-specific fixation both achieve good and similar patient-reported outcomes, although more complications were recorded in the fragment-specific group. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Similar 1-year subjective outcome after a distal radius fracture during the 10-year-period 2003-2012.

Background and purpose - During the last decades, treatment of distal radius fractures (DRFs) has changed, with surgical intervention being more common and with new techniques. We investigated whether this change has influenced the subjective outcome. Here we report, year by year, the 1-year score after a DRF over a 10-year-period, using a patient-reported outcome measure. Patients and methods - Patients aged 18 years or more with a DRF between 2003 and 2012 were prospectively and consecutively registered in a longitudinal outcome database. 1 year after the fracture, all the patients were sent a validated subjective outcome questionnaire, the Disabilities of the Arm, Shoulder, and Hand (DASH). The lower the score (0-100), the better the outcome. Results - Between 2003 and 2012, 3,666 patients (2,833 of them women; mean age 62 (18-98) years) were included. 22% were operated and the rate remained constant over the years. The surgical methods shifted from external fixators (42%) and fragment-specific plates (45%) in 2003, to mainly volar locking plates (65%) in 2012. 70% of the patients responded to the 1-year DASH questionnaire. The median DASH score was 9 (IQR: 2-25) for the cohort, both in surgically treated patients (9 (IQR: 3-25)) and in non-surgically treated patients (9 (IQR 2-27)). Subgroup analysis showed a higher median DASH score for women than for men; for patients with AO type C fractures rather than type B or type A fractures; for patients with external fixation or fragment-specific fixation than for those who underwent surgery using volar locking plates; and for patients who were operated by a general orthopedic surgeon rather than a hand surgeon. Interpretation - The shift in surgical treatment had no influence on the subjective outcome for the cohort.

Bone mineral crystal size and organization vary across mature rat bone cortex.

The macro- and micro-features of bone can be assessed by using imaging methods. However, nano- and molecular features require more detailed characterization, such as use of e.g., vibrational spectroscopy and X-ray scattering. Nano- and molecular features also affect the mechanical competence of bone tissue. The aim of the present study was to reveal the effects of mineralization and its alterations on the mineral crystal scale, by investigating the spatial variation of molecular composition and mineral crystal structure across the cross-section of femur diaphyses in young rats, and healthy and osteoporotic mature rats (N=5). Fourier transform infrared spectroscopy and scanning small- and wide-angle X-ray scattering (SAXS/WAXS) techniques with high spatial resolution were used at identical locations over the whole cross-section. This allowed quantification of point-by-point information about the spatial distribution of mineral crystal volume. All measured parameters (crystal dimensions, degree of orientation and predominant orientation) varied across the cortex. Specifically, the crystal dimensions were lower in the central cortex than in the endosteal and periosteal regions. Mineral crystal orientation followed the cortical circumference in the periosteal and endosteal regions, but was less well-oriented in the central regions. Central cortex is formed rapidly during development through endochondral ossification. Since rats possess no osteonal remodeling, this bone remains (until old age). Significant linear correlations were observed between the dimensional and organizational parameters, e.g., between crystal length and degree of orientation (R(2)=0.83, p<0.001). Application of SAXS/WAXS provides valuable information on bone nanostructure and its constituents, effects of diseases and, prospectively, mechanical competence.

Characterizing the composition of bone formed during fracture healing using scanning electron microscopy techniques.

About 5-10% of all bone fractures suffer from delayed healing, which may lead to non-union. Bone morphogenetic proteins (BMPs) can be used to induce differentiation of osteoblasts and enhance the formation of the bony callus, and bisphosphonates help to retain the newly formed callus. The aim of this study was to investigate if scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) can identify differences in the mineral composition of the newly formed bone compared to cortical bone from a non-fractured control. Moreover, we investigate whether the use of BMPs and bisphosphonates-alone or combined-may have an effect on bone mineralization and composition. Twelve male Sprague-Dawley rats at 9 weeks of age were randomly divided into four groups and treated with (A) saline, (B) BMP-7, (C) bisphosphonates (Zoledronate), and (D) BMP-7 + Zoledronate. The rats were sacrificed after 6 weeks. All samples were imaged using SEM and chemically analyzed with EDS to quantify the amount of C, N, Ca, P, O, Na, and Mg. The Ca/P ratio was the primary outcome. In the fractured samples, two areas of interest were chosen for chemical analysis with EDS: the callus and the cortical bone. In the non-fractured samples, only the cortex was analyzed. Our results showed that the element composition varied to a small extent between the callus and the cortical bone in the fractured bones. However, the Ca/P ratio did not differ significantly, suggesting that the mineralization at all sites is similar 6 weeks post-fracture in this rat model.

Characterising bone material composition and structure in the ovariectomized (OVX) rat model of osteoporosis.

The ovariectomized (OVX) rat model is well established in investigations of osteoporosis and osteoporotic therapies. Advent of techniques such as Fourier-transform infrared (FTIR) spectroscopy and small angle X-ray scattering (SAXS) facilitate characterization of bone composition and mineral structure, respectively, which are key determinants of bone strength. Limited publications exist on the implementation of these techniques in the OVX rat model. At 12 weeks of age, female Sprague-Dawley rats were either sham-operated (n = 6) or ovariectomized (n = 6) and sacrificed 18 weeks later. L2 lumbar vertebrae and proximal tibiae were assessed by µCT, FTIR and SAXS. Presence of extensive trabecular deterioration in the µCT data confirmed the onset of osteoporosis. FTIR compositional parameters were determined including measures of degree of mineralization, crystallinity, collagen maturity and acid phosphate content. Mineral crystal thickness was determined from the SAXS data using two approaches available in literature. Compositionally, a decline in the heterogeneity of acid phosphate content was observed while measures of crystallinity and collagen maturity remained unaltered. Using an iterative curve fitting method, OVX-induced increases in the mineral crystal thickness of 3.8 and 7.8 % (p < 0.05) were noted in the trabecular of the vertebra and tibia, respectively. In conclusion, implementation of FTIR and SAXS techniques in the OVX rat model, identified no significant compositional changes while substantiating thickening of the mineral crystals as a general structural feature of OVX-induced osteoporosis in rats.

Arthroscopically diagnosed scapholunate ligament injuries associated with distal radial fractures: a 13- to 15-year follow-up.

PURPOSE: To evaluate the natural history of untreated complete or partial scapholunate (SL) ligament tears associated with displaced distal radius fractures. METHODS: Between 1995 and 1997, 51 consecutive patients aged < 60 years with displaced distal radius fractures were examined arthroscopically to assess for concomitant soft tissue injuries. Thirty-two of 51 patients had an SL ligament tear, 10 had a complete tear (Lindau grade 3), and 22 had a partial tear (Lindau grades 1 and 2). Thirty-two patients had AO type-C fractures, 3 had type-B fractures, and 16 had type-A fractures. In 2010, 47 of the 51 patients were still alive, and they were invited for an interview, clinical examination, and radiography. RESULTS: Thirty-eight of the 51 original patients participated in the long-term follow-up. Mean grip strength was 83% relative to the contralateral hand in patients with a complete tear, as compared with 92% in patients with partial or no SL tears (nonsignificant). Median Disabilities of the Arm, Shoulder, and Hand questionnaire score was 2 (range, 0‒55) for complete SL tears, compared with 9 (range, 0‒70) for the others (nonsignificant). No differences were found regarding visual analog scale pain or wrist motion/forearm rotation. None of the patients developed a static SL dissociation or a SL advanced collapse wrist. CONCLUSIONS: No major differences were found in the subjective, objective, or radiographic outcome after a complete (grade 3) or partial (grade 1 or 2) SL untreated tear associated with displaced distal radius fracture. It should be noted that none of the patients had a grade 4 SL tear, which may have a different outcome. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Patients Aged 80 or More With Distal Radius Fractures Have a Lower One-Year Mortality Rate Than Age- and Gender-Matched Controls: A Register-Based Study.

Introduction: With a rapidly ageing population, the number of distal radius fractures (DRFs) in the elderly will increase dramatically. The aim of this retrospective register study was to examine the 1- and 5-year mortality in DRF patients aged 80 years or more and correlate the overall survival to factors not related to the fracture itself. Material and Methods: Patients aged ≥80 diagnosed with DRFs in Lund University Hospital in Sweden in the period 2010-2012 were extracted from the prospective Lund Distal Radius Fracture register. One- and 5-year standardised mortality rates (SMRs) were calculated using the Swedish standard population as a reference. Medical records were searched for non-fracture-related factors including comorbidity, medications, cognitive impairment and type of living. Cox proportional hazard regression models were used to identify prognostic factors for all-cause mortality. Results: The study cohort included 240 patients, with a mean age of 86. The overall 1-year mortality was 5% (n = 11/240) and the 5-year mortality was 44% (n = 105/240). The 1-year SMR was .44 (CI .18-.69, P < .01) when indirectly adjusted for age and gender and compared to the Swedish standard population. The 5-year SMR was .96 (CI .78-1.14). The patients' ability to live independently in their own home had the highest impact on survival. Discussion: The 1-year mortality rate among the super-elderly DRF patients was only 44% of that expected. Possibly, a DRF at this age could be a sign of a healthier and more active patient. Conclusions: The DRF patients aged 80 or more had a substantially lower mortality rate 1 year after fracture compared to the age- and gender-matched standard population. Patients living independently in their own homes had the longest life expectancy. Treatment should not be limited solely because of old age, but individualised according to the patient's ability and activity level.

Co-delivery of rhBMP-2 and zoledronic acid using calcium sulfate/hydroxyapatite carrier as a bioactive bone substitute to enhance and accelerate spinal fusion.

Recombinant human bone morphogenetic protein-2 (rhBMP-2) has been FDA-approved for lumbar fusion, but supraphysiologic initial burst release due to suboptimal carrier and late excess bone resorption caused by osteoclast activation have limited its clinical usage. One strategy to mitigate the pro-osteoclast side effect of rhBMP-2 is to give systemic bisphosphonates, but it presents challenges with systemic side effects and low local bioavailability. The aim of this in vivo study was to analyze if posterolateral spinal fusion (PLF) could be improved by utilizing a calcium sulfate/hydroxyapatite (CaS/HA) carrier co-delivering rhBMP-2 and zoledronic acid (ZA). Six groups were allocated (CaS/HA, CaS/HA + BMP-2, CaS/HA + systemic ZA, CaS/HA + local ZA, CaS/HA + BMP-2 + systemic ZA, and CaS/HA + BMP-2 + local ZA). 10-week-old male Wistar rats, were randomly assigned to undergo L4-L5 PLF with implantation of group-dependent scaffolds. At 3 and 6 weeks, the animals were euthanized for radiography, µCT, histological staining, or biomechanical testing to evaluate spinal fusion. The results demonstrated that the CaS/HA biomaterial alone or in combination with local or systemic ZA didn't support PLF. However, the delivery of rhBMP-2 significantly promoted PLF. Combining systemic ZA with BMP-2 didn't enhance spinal fusion. Notably, the co-delivery of rhBMP-2 and ZA using the CaS/HA carrier significantly enhanced and accelerated PLF, without inhibiting systemic bone turnover, and potentially reduced the dose of rhBMP-2. Together, the treatment regimen of CaS/HA biomaterial co-delivering rhBMP-2 and ZA could potentially be a safe and cost-effective off-the-shelf bioactive bone substitute to enhance spinal fusion.

Systemically administered zoledronic acid activates locally implanted synthetic hydroxyapatite particles enhancing peri-implant bone formation: A regenerative medicine approach to improve fracture fixation.

Fracture fixation in an ageing population is challenging and fixation failure increases mortality and societal costs. We report a novel fracture fixation treatment by applying a hydroxyapatite (HA) based biomaterial at the bone-implant interface and biologically activating the biomaterial by systemic administration of a bisphosphonate (zoledronic acid, ZA). We first used an animal model of implant integration and applied a calcium sulphate (CaS)/HA biomaterial around a metallic screw in the tibia of osteoporotic rats. Using systemic ZA administration at 2-weeks post-surgery, we demonstrated that the implant surrounded by HA particles showed significantly higher peri­implant bone formation compared to the unaugmented implants at 6-weeks. We then evaluated the optimal timing (day 1, 3, 7 and 14) of ZA administration to achieve a robust effect on peri­implant bone formation. Using fluorescent ZA, we demonstrated that the uptake of ZA in the CaS/HA material was the highest at 3- and 7-days post-implantation and the uptake kinetics had a profound effect on the eventual peri­implant bone formation. We furthered our concept in a feasibility study on trochanteric fracture patients randomized to either CaS/HA augmentation or no augmentation followed by systemic ZA treatment. Radiographically, the CaS/HA group showed signs of increased peri­implant bone formation compared with the controls. Finally, apart from HA, we demonstrated that the concept of biologically activating a ceramic material by ZA could also be applied to ß-tricalcium phosphate. This novel approach for fracture treatment that enhances immediate and long-term fracture fixation in osteoporotic bone could potentially reduce reoperations, morbidity and mortality. STATEMENT OF SIGNIFICANCE: • Fracture fixation in an ageing population is challenging. Biomaterial-based augmentation of fracture fixation devices has been attempted but lack of satisfactory biological response limits their widespread use. • We report the biological activation of locally implanted microparticulate hydroxyapatite (HA) particles placed around an implant by systemic administration of the bisphosphonate zoledronic acid (ZA). The biological activation of HA by ZA enhances peri­implant bone formation. •Timing of ZA administration after HA implantation is critical for optimal ZA uptake and consequently determines the extent of peri­implant bone formation. • We translate the developed concept from small animal models of implant integration to a proof-of-concept clinical study on osteoporotic trochanteric fracture patients. • ZA based biological activation can also be applied to other calcium phosphate biomaterials.

Augmentation of autologous bone graft by a combination of bone morphogenic protein and bisphosphonate increased both callus volume and strength.

BACKGROUND AND PURPOSE: Bone morphogenic proteins (BMPs) can be used in non-unions to replace autograft. BMPs induce osteoblasts and (less well known) also osteoclasts, which can in turn be controlled by a bisphosphonate. In the present study, our aim was to improve the biological effect of autologous bone graft by adding an anabolic BMP, with or without bisphosphonates, in an open-fracture model prone to non-union. METHODS: Rat femurs were osteotomized and fixed with an intramedullary K-wire. Autograft was placed at the osteotomy, mixed with either saline or BMP-7. After 2 weeks, the rats had a single injection of saline or of a bisphosphonate (zoledronate). The rats were killed after 6 weeks and the femurs were evaluated by radiography, micro-CT, histology, and 3-point bending test. RESULTS: All fractures healed. The callus volume was doubled in the BMP-treated femurs (p < 0.01) and increased almost 4-fold in the femurs treated with both BMP and systemic zoledronate (p < 0.01) compared to autograft. In mechanical testing, the autograft group reached approximately half the strength of the contralateral, non-osteotomized femur (p < 0.001). By adding BMP to the autograft, the strength was doubled (p < 0.001) and with both BMP and systemic zoledronate, the strength was increased 4-fold (p < 0.001) compared to autograft alone. INTERPRETATION: The combination of BMP and bisphosphonate as an adjunct to autograft is superior to autograft alone or combined with BMP. The combination may prove valuable in the treatment of non-unions.

The natural course of spontaneous osteonecrosis of the knee (SPONK): a 1- to 27-year follow-up of 40 patients.

BACKGROUND AND PURPOSE: Spontaneous osteonecrosis of the knee (SPONK) is a painful lesion in the elderly, frequently leading to osteoarthritis and subsequent knee surgery. We evaluated the natural course and long-term consequences of SPONK in terms of need for major knee surgery. METHODS: Between 1982 and 1988, 40 consecutive patients were diagnosed with SPONK. The short-term outcome has been reported previously (1991). After 1-7 years, 10 patients had a good radiographic outcome and 30 were considered failures, developing osteoarthritis. In 2012, all 40 of the patients were matched with the Swedish Knee Arthroplasty Register (SKAR) and their medical records were reviewed to evaluate the long-term need for major knee surgery. RESULTS: At the 2012 review, 33 of the 40 patients had died. The mean follow-up time from diagnosis to surgery, death, or end of study was 9 (1-27) years. 17 of 40 patients had had major knee surgery with either arthroplasty (15) or osteotomy (2). All operated patients but 1 were in the radiographic failure group and had developed osteoarthritis in the study from 1991. 6 of 7 patients with large lesions (> 40% of the AP radiographic view of the condyle) at the time of the diagnosis were operated. None of the 10 patients with a lesion of less than 20% were ever operated. INTERPRETATION: It appears that the size of the osteonecrotic lesion can be used to predict the outcome. Patients showing early signs of osteoarthritis or with a large osteonecrosis have a high risk of later major knee surgery.

Virtual Follow up After Distal Radius Fracture Surgery-Patient Experiences During the COVID-19 Pandemic.

The majority of patients with a distal radius fracture (DRF) are elderly, a group known to experience difficulties with new technology, partly due to a low level of digital literacy. At the beginning of the coronavirus disease 2019 pandemic, during the spring 2020, patients that underwent DRF surgery had regular follow-ups replaced by video calls from their surgeon and physiotherapist. Afterward, patients answered questionnaires regarding health and digital literacy and took part in semistructured interviews regarding the experience of the virtual follow-up. By systemic text condensation, 2 major categories were identified: (1) The video call-new, but surprisingly simple: All but 1 found it easier than expected, and (2) Video calls-the patient's choice: All but 1 patient preferred video calls to physical visits for follow-up. This is the first mixed methods study to assess patients' experiences of digital follow-up after DRF surgery. This study indicates that digital follow-up was highly appreciated, even among patients with low levels of digital literacy. Digital technologies must be made suitable even for patients with inadequate levels of digital literacy.

Systemic rifampicin shows accretion to locally implanted hydroxyapatite particles in a rat abdominal muscle pouch model.

Introduction: biomaterials combined with antibiotics are routinely used for the management of bone infections. After eluting high concentrations of antibiotics during the first week, sub-inhibitory concentrations of antibiotics may lead to late repopulation of recalcitrant bacteria. Recent studies have shown that systemically given antibiotics like tetracycline and rifampicin (RIF) could seek and bind to locally implanted hydroxyapatite (HA). The aim of this in vivo study was to test if systemically administered rifampicin could replenish HA-based biomaterials with or without prior antibiotic loading to protect the material from late bacterial repopulation. Methods: in vivo accretion of systemically administered RIF to three different types of HA-based materials was tested. In group 1, nano (n)- and micro (m)-sized HA particles were used, while group 2 consisted of a calcium sulfate / hydroxyapatite (CaS / HA) biomaterial without preloaded antibiotics gentamycin (GEN) or vancomycin (VAN), and in group 3, the CaS / HA material contained GEN (CaS / HA + GEN) or VAN (CaS / HA + VAN). The above materials were implanted in an abdominal muscle pouch model in rats, and at 7 d post-surgery, the animals were assigned to a control group (i.e., no systemic antibiotic) and a test group (i.e., animals receiving one single intraperitoneal injection of RIF each day (4 mg per rat) for 3 consecutive days). Twenty-four hours after the third injection, the animals were sacrificed and the implanted pellets were retrieved and tested against Staphylococcus aureus ATCC 25923 in an agar diffusion assay. After overnight incubation, the zone of inhibition (ZOI) around the pellets were measured. Results: in the control group, 2 / 6 CaS / HA + GEN pellets had a ZOI, while all other harvested pellets had no ZOI. No pellets from animals in test group 1 had a ZOI. In test group 2, 10 / 10 CaS / HA pellets showed a ZOI. In test group 3, 5 / 6 CaS / HA + GEN and 4 / 6 CaS / HA + VAN pellets showed a ZOI. Conclusions: in this proof-of-concept study, we have shown that a locally implanted biphasic CaS / HA carrier after 1 week can be loaded by systemic RIF administration and exert an antibacterial effect. Further in vivo infection models are necessary to validate our findings.

Association Between Radiographic and Clinical Outcomes Following Distal Radial Fractures: A Prospective Cohort Study with 1-Year Follow-up in 366 Patients.

BACKGROUND: Several studies of distal radial fractures have investigated final displacement and its association with clinical outcomes. There is still no consensus on the importance of radiographic outcomes, and published studies have not used the same criteria for acceptable alignment. Previous reports have involved the use of linear or dichotomized analyses. METHODS: The present study included 438 patients who were managed with either reduction and cast immobilization or surgery for the treatment of distal radial fractures. Radiographic outcomes were determined on the basis of radiographs that were made 3 months after the injury. Clinical outcome was determined on the basis of the QuickDASH (an abbreviated version of the Disabilities of the Arm, Shoulder and Hand [DASH] questionnaire) score, range of motion, and grip strength at 1 year after the injury. Nonlinear relations were analyzed with cubic splines. RESULTS: Three hundred and sixty-six patients (84%) had both radiographic and clinical follow-up. Seventy patients were lost to follow-up. The mean age was 57 years (range, 18 to 75 years), and 79% of the patients were female. Dorsal tilt was the radiographic parameter that was most strongly associated with the QuickDASH score, grip strength, and range of motion. We found nonlinear relations. Clinical outcomes were found to worsen with increasing dorsal tilt, with the cutoff value being approximately 5°. CONCLUSIONS: We found that clinical outcomes following distal radial fractures have a nonlinear relationship with dorsal tilt, with worse outcomes being associated with increasing dorsal tilt. The decline in clinical outcome starts at 5°, but there is unlikely to be a noticeable difference in capability as measured with the QuickDASH until 20° of dorsal tilt (based on the minimum clinically important difference) in a population up to 75 years old. LEVEL OF EVIDENCE: Diagnostic Level II . See Instructions for Authors for a complete description of levels of evidence.