The aim of this study was to determine medium term functional outcomes in military casualties undergoing limb salvage for severe open tibia fractures, and compare them to trans-tibial amputees. Cases of severe open diaphyseal tibia fractures sustained in combat between 2006 – 2010 were contacted and interviewed. These results were compared to a similar cohort of 18 military patients who sustained a unilateral trans-tibial amputation in the same period. Forty-nine patients with 57 severe open tibia fractures met the inclusion criteria, of which 30 patients (61%) were followed-up. Ten of the 30 patients required revision surgery, 3 of which involved conversion to a circular frame. Twenty-two of the 30 patients (73%) recovered sufficiently to complete a basic military fitness test. The median physical component score of SF-36 in the limb salvage group was 46 (IQR 35–54) which was similar to the trans-tibial amputation cohort (p=0.3057, Mann-Whitney). There was no significant difference in the proportion of patients in either the amputation or limb salvage group reporting pain (p=0.1157, Fisher's exact test) or with respect to SF-36 physical pain scores (p=0.5258, Mann-Whitney). This study demonstrates that medium term outcomes for military patients are similar following trans-tibial amputation or limb salvage following combat trauma

The aim of this study was to establish medium term outcomes in military casualties following severe open tibia fractures. Cases from a previously published series were contacted and assessed with the SF-36 outcome tool. Their results were then compared to a similar study of military trans-tibial amputees. Of the original data set of 49 patients, 30 patients were followed up and completed an SF-36 (61%) with a median follow-up of 4 years (49 months, IQR 397–63). Ten of the 30 required revision surgery, 3 of which involved conversion from initial fixation to a circular frame. Twenty-two of the 30 patients recovered sufficiently to complete a military basic fitness test. The median physical component of SF-36 in the tibia fracture group was 46 (IQR 35–54) which was similar to the trans-tibial amputation cohort (p=0.3057, Mann-Whitney). Similarly there was no difference in mental component scores (p=0.1595, Mann-Whitney). There was no significant difference in the proportion of patients in the amputation or fracture group reporting pain (p= 0.1157, Fisher's exact test) or with respect to SF-36 physical pain scores (p=0.5258, Mann-Whitney). We present the patient reported outcomes following combat open tibia fracture and show that they are similar to those achieved after trans-tibial amputation

Introduction: Goal of study to demonstrate that treatment with low-intensity pulsed ultrasound [LIPUS] results in greater increases in bone density and greater reductions in bone gap area as compared to sham control in tibia fractures with delayed union (no progression of healing for at least four months). Methods: Two primary effectiveness variables, change of bone density and gap area during treatment, were selected as surrogates for bone healing. Abbreviated treatment period was maximum that sham treatment could be administered ethically. Both variables measured by blinded central reviewers from CT-scans taken before/after termination of treatment. All adverse events recorded, evaluated. Treatment duration was 16wks. Patients instructed to apply device once daily for 20 minutes. Control devices were visually identical but did not transmit ultrasound waves. Neither patients nor physicians could recognize shams. Results: 101 patients enrolled (51 LIPUS, 50 sham), mean age 42.6 (active) versus 45.1 years (sham). Based on log-transformed data, mean improvement in bone density was 1.34 (90% CI 1.14 to 1.57) times greater for patients randomized to LIPUS compared to sham (p=0.002). A mean reduction in bone gap area also favored LIPUS treatment (p=0.014). Conclusion: Double-blind, intent-to-treat analyses demonstrated statistically significant superior effectiveness for LIPUS device compared to sham in terms of both endpoints over 16wks of treatment. Estimated increase in bone density among patients randomized to LIPUS treatment was 34% greater than among patients randomized to sham. A significantly greater mean reduction in bone gap area after LIPUS treatment was also shown. Evaluation of adverse events showed that ultrasound therapy is safe

Objectives

Proximal tibial fracture is one of the most common postoperative complications of unilateral knee arthroplasty (UKA). The objective of the present study is to investigate the risk factors of these fractures, occurred after UKA in our facility.

A multicenter retrospective analysis of patients treated for tibial fracture was conducted to develop a score that correlates with fracture healing time and, ultimately, to identify the risk gradient of delayed healing.

The clinical records of 93 patients treated for tibial fracture at three orthopaedic centers were evaluated. Patients were considered healed when full weight bearing was allowed and no further controls were scheduled. For the purpose of our analysis, we separated patients healed within or after 180 days.

Patient's risk factors known to be associated to delay healing, as well as fracture morphology and orthopaedic treatment were recorded in an electronic Case Report Form (e-CRF). Information available in the literature was used to weight the relative risk (RR) associated to each risk factor; values were combined to calculate a score to be correlated to the fracture healing time: L-ARRCO (Literature-Algoritmo Rischio Ritardo Consolidazione Ossea). Among all information collected in e-CRFs, we identified other risk factors, associated to delayed healing, that were used to calculate a new score: ARRCO. Univariate logistic analysis was used to determine a correlation between the score and healing time. Analysis by receiver operating characteristic (ROC) and calculation of the area under the curve (AUC) were used for sensitivity and specificity.

Complete information was available for 53 patients. The mean value of the L-ARRCO score among patients healed within 180 days was 5.78 ± 1.59 and 7.05 ± 2.46 among those healed afterwards, p=0.044. The mean value of the ARRCO score of patients healed within 180 days was 5.92 ± 1.78 and 9.03 ± 2.79 among those healed afterwards, p<0.0001. The ROC curve shows an AUC of 0.62±0.09 for L-ARRCO and an AUC of 0.82±0.07 for ARRCO, (p<0.0001).

We have shown that the ARRCO score value is significantly correlated to fracture healing time. The score may be used to identify fractures at risk of delayed healing, thus allowing surgeon's early intervention to stimulate osteogenesis.

Aims

The aim of this study was to determine the immediate post-fixation stability of a distal tibial fracture fixed with an intramedullary nail using a biomechanical model. This was used as a surrogate for immediate weight-bearing postoperatively. The goal was to help inform postoperative protocols.

Since the introduction of carving skis, the injuries of the tibia is changing from simple fractures of the diaphyse to complex fractures of the epiphyses, according to high energy traumas. There are no studies about results of the treatment and consequences after winter sport accidents. Method: Prospective documentation of all proximal tibia fractures after winter sport accidents, which were treated between 01.12.2006 and 31.04.2009 in the Trauma Department of the Klinikum Garmisch-Parten-kirchen, Germany. X-Rays and CT scans were classified according to the AO –Classification. Operations, complications, co-injuries and the hospital stay were analysed. We performed the Lysholm score, WOMAC Knee-score and the Tegner-index on the day of injury, 6 months, 12 months, and 2 years after injury. Results: 78 patients had a proximal tibia fracture following a skiing accident, 36 Male and 42 female. All except two patients had a monotrauma of the proximal tibia. Mean age 46 ± 15 years. 17 types A.1.3, 41 types B and 18 types C3 fractures. 4 patients developed a compartment syndrome, one patient had a lesion of the n. peroneus. 65 patients were operated in our hospital. In 8 patients we performed a conservative treatment. The mean hospital stay was 12 ± 7.5 days. In 15 patients a menisci reconstruction was necessary. 6 patients had a postoperative complication: 3 thromboses, 2 cardiac decompensations, 1 wound healing problems. By now 42 patients were ready for follow-up. So far the mean follow-up time is 13.8 months. The Lysholm score was at 12 months (n= 22) 78 ± 20 points. The Tegner score was pre-injury 6.2 ± 1.1 and 12 months post-injury 4.1 ± 1,8. The results of the WOMAC score show an improvement in the subcategories pain and function in all patients. In the subcategory stiffness only the type A and B fractures show an improvement during the follow-up. Conclusion: The proximal tibia joint fractures are a serious injury. The most patients’ activity level is tremendously reduced. The major problem after one year seems to be the ligament instability of the knee. A beginning knee arthritis after one year becomes relevant only in the type C fractures. More effort for the prevention of the proximal tibia fractures while skiing is necessary

We report on the use of the Ilizarov method to treat 40 consecutive fractures of the tibial shaft (35 AO 42C fractures and five AO 42B3 fractures) in adults. There were 28 men and 12 women with a mean age of 43 years (19 to 81). The series included 19 open fractures (six Gustilo grade 3A and 13 grade 3B) and 21 closed injuries. The mean time from injury to application of definitive Ilizarov frame was eight days (0 to 35) with 36 fractures successfully uniting without the need for any bone-stimulating procedure. The four remaining patients with nonunion healed with a second frame. There were no amputations and no deep infections. None required intervention for malunion. The total time to healing was calculated from date of injury to removal of the frame, with a median of 166 days (mean 187, (87 to 370)). Minor complications included snapped wires in two patients and minor pin-site infections treated with oral antibiotics in nine patients (23%). Clinical scores were available for 32 of the 40 patients at a median of 55 months (mean 62, (26 to 99)) post-injury, with ‘good’ Olerud and Molander ankle scores (median 80, mean 75, (10 to 100)), ‘excellent’ Lysholm knee scores (median 97, mean 88, (29 to 100)), a median Tegner activity score of 4 (mean 4, (0 to 9)) (comparable to ‘moderately heavy labour / cycling and jogging’) and Short Form-12 scores that exceeded the mean of the population as a whole (median physical component score 55 (mean 51, (20 to 64)), median mental component score 57 (mean 53, (21 to 62)). In conclusion, the Ilizarov method is a safe and reliable way of treating complex tibial shaft fractures with a high rate of primary union.

Using human cadaver specimens, we investigated the role of supplementary fibular plating in the treatment of distal tibial fractures using an intramedullary nail. Fibular plating is thought to improve stability in these situations, but has been reported to have increased soft-tissue complications and to impair union of the fracture. We proposed that multidirectional locking screws provide adequate stability, making additional fibular plating unnecessary. A distal tibiofibular osteotomy model performed on matched fresh-frozen lower limb specimens was stabilised with reamed nails using conventional biplanar distal locking (CDL) or multidirectional distal locking (MDL) options with and without fibular plating. Rotational stiffness was assessed under a constant axial force of 150 N and a superimposed torque of ± 5 Nm. Total movement, and neutral zone and fracture gap movement were analysed.

In the CDL group, fibular plating improved stiffness at the tibial fracture site, albeit to a small degree (p = 0.013). In the MDL group additional fibular plating did not increase the stiffness. The MDL nail without fibular plating was significantly more stable than the CDL nail with an additional fibular plate (p = 0.008).

These findings suggest that additional fibular plating does not improve stability if a multidirectional distal locking intramedullary nail is used, and is therefore unnecessary if not needed to aid reduction.

Cite this article: Bone Joint J 2014;96-B:385–9.

The August 2023 Trauma Roundup. 360. looks at: A comparison of functional cast and volar-flexion ulnar deviation for dorsally displaced distal radius fractures; Give your stable ankle fractures some AIR!; Early stabilization of rib fractures – an effective thing to do?; Locked plating versus nailing for proximal tibia fractures: A multicentre randomized controlled trial; Time to flap coverage in open tibia fractures; Does tranexamic acid affect the incidence of heterotropic ossification around the elbow?; High BMI – good or bad in surgical fixation of hip fractures?

Open tibia fractures are common injuries in our paediatric population and are often associated with high-energy trauma such as pedestrian-vehicle accidents. At our institution, these injuries are routinely treated with debridement and mono-lateral external fixation. The purpose of this study was to determine the outcome of open tibia fractures treated according to this protocol, as well as the complication rate and factors contributing to the development of complications. We performed a retrospective folder review of all patients with open tibia fractures that were treated according to our protocol from 2015–2019. Patients treated by other means, who received primary treatment elsewhere, and with insufficient data, were excluded. Data was collected on presenting demographics, injury characteristics, management, and clinical course. Complications were defined as pin tract infections, delayed- or non-union, malunion, growth arrest, and neurovascular injury. Appropriate statistical analysis was performed. One-hundred-and-fifteen fractures in 114 children (82 males) with a median age of 7 years (IQR 6–9) were included in the analysis. Pedestrian vehicle accidents (PVA's) accounted for 101 (88%) of fractures, and the tibial diaphysis was affected in 74 cases (64%). Fracture severity was equally distributed among the Gustillo-Anderson grades. The median Abbreviated Injury Score was 4 (IQR 4;5). Ninety-five fractures (83%) progressed to uneventful union within 7 weeks. Twenty patients (17%) developed complications, with delayed union and fracture site infections being the most common complications. Gustillo-Anderson Grade 3 fractures, an increased Abbreviated Injury Score, and the need for advanced wound closure techniques were risk factors for developing complications. Surgical debridement and external fixation in a simple mono-lateral frame is an effective treatment for open tibia fractures in children and good outcomes were seen in 83% of patients. More severe injuries requiring advanced wound closure were associated with the development of complications

Aims: To present the experience of our department in the treatment of the closed shaft tibial fractures using the unreamed nail of Orthoþx. Material- Method: Between 1991–2001 we treated 180 closed fractures. There were162 men and 18 women. The preferred method of stabilization is unreamed nailing. Results: The average follow-up was 38 months. 165 of the fractures that were treated with uiin, healed in the proper time (3–6 months). The rest of them did not have callus signs and we revised the nailing using reamed nails. No screws and nail failure was observed. Three deep venous thrombosis, healed with no further complications. 65% of our patients were able to return to their usual activities within 4 months and the rest between 4–8 months. 15 non-unions and 2 malunions occurred and were treated with correction and reamed interlocking nailing. P.W.B. allowed for fractures type A and B according AO classiþcation from the beginning. F.W.B. allowed at mean 3 months. Conclusions: Immediate stabilization of the close fractures of the tibia using uiin (Orthoþx device): advances the healing of the fractures, decreases hospitalization time, helps early return to social activities, is easier for the surgeon, easier to place the distal locking screws, requires less operative time and less radiation. We did not þnd this method inferior to reamed interlocking nailing.

Aims. The optimal bearing surface design for medial unicompartmental knee arthroplasty (UKA) remains controversial. The aim of this study was to compare outcomes of fixed-bearing (FB) and mobile-bearing (MB) UKAs from a single high-volume institution. Methods. Prospectively collected data were reviewed for all primary cemented medial UKAs performed by seven surgeons from January 2006 to December 2022. A total of 2,999 UKAs were identified, including 2,315 FB and 684 MB cases. The primary outcome measure was implant survival. Secondary outcomes included 90-day and cumulative complications, reoperations, component revisions, conversion arthroplasties, range of motion, and patient-reported outcome measures. Overall mean age at surgery was 65.7 years (32.9 to 94.3), 53.1% (1,593/2,999) of UKAs were implanted in female patients, and demographics between groups were similar (p > 0.05). The mean follow-up for all UKAs was 3.7 years (0.0 to 15.6). Results. Using revision for any reason as an endpoint, five-year survival for FB UKAs was 97.2% (95% CI 96.4 to 98.1) compared to 96.0% for MB (95% CI 94.1 to 97.9; p = 0.008). The FB group experienced fewer component revisions (14/2,315, 0.6% vs 12/684, 1.8%; p < 0.001) and conversion arthroplasties (38/2315, 1.6% vs 24/684, 3.5%; p < 0.001). A greater number of MB UKAs underwent revision due to osteoarthritis progression (FB = 21/2,315, 0.9% vs MB = 16/684, 2.3%; p = 0.003). In the MB group, 12 (1.8%) subjects experienced bearing dislocations which required revision surgery. There were 15 early periprosthetic tibia fractures (0.6%) in the FB group compared to 0 for MB (p = 0.035). Conclusion. In similar patient populations, FB UKAs demonstrated slightly higher survival than a commonly used MB design. Adverse event profiles differed by bearing type, with an increased risk of bearing dislocation and OA progression with MB designs, and early periprosthetic tibia fractures for FB designs. Cite this article: Bone Joint J 2024;106-B(9):916–923

Introduction. Diaphyseal tibial fractures account for approximately 1.9% of adult fractures. Several studies demonstrate a high proportion of diaphyseal tibial fractures have ipsilateral occult posterior malleolus fractures, this ranges from 22–92.3%. Materials and Methods. A retrospective review of a prospectively collected database was performed at Liverpool University Hospitals NHS Foundation Trust between 1/1/2013 and 9/11/2020. The inclusion criteria were patients over 16, with a diaphyseal tibial fracture and who underwent a CT. The articular fracture extension was categorised into either posterior malleolar (PM) or other fracture. Results. 764 fractures were analysed, 300 had a CT. There were 127 intra-articular fractures. 83 (65.4%) cases were PM and 44 were other fractures. On univariate analysis for PM fractures, fibular spiral (p=.016) fractures, no fibular fracture(p=.003), lateral direction of the tibial fracture (p=.04), female gender (p=.002), AO 42B1 (p=.033) and an increasing angle of tibial fracture. On multivariate regression analysis a high angle of tibia fracture was significant. Other fracture extensions were associated with no fibular fracture (p=.002), medial direction of tibia fracture (p=.004), female gender (p=.000), and AO 42A1 (p=.004), 42A2 (p=.029), 42B3 (p=.035) and 42C2 (p=.032). On multivariate analysis, the lateral direction of tibia fracture, and AO classification 42A1 and 42A2 were significant. Conclusions. Articular extension happened in 42.3%. A number of factors were associated with the extension, however multivariate analysis did not create a suitable prediction model. Nevertheless, rotational tibia fractures with a high angle of fracture should have further investigation with a CT

Orthopaedic injuries in the knee are often associated with vascular injury. When these vascular injuries are missed devastating there are devastating outcomes like limb ablation. Pulse examination in these patients is not sensitive to exclude vascular injuries. That often lead to clinicians opting for Computed Tomography Angiogram (CTA) to exclude vascular. this usually leads to a burden in Radiology Department. This study aimed to evaluate the prevalence of vascular injury in patient with orthopaedic injury in the knee. The computed tomography (CT) done in patients with distal femur fracture, knee dislocation and proximal tibia fractures were retrieved from the picture archiving and comunication system (PACS). The CTs were done between June 2017 and June 2022. The computed tomography angiogram (CTA) reports were reviewed to determine cases that vascular injury. A sample size of 511 cases was collected. 386 cases were done CTA and 125 cases were not done CTA. There were 218 tibial plateau fractures, 79 knee dislocations, 72 distal metaphyseal femur fractures, 61 floating knees, 55 distal femure intraarticular and 26 proximal metaphyseal tibia fractures. The mechanisms of injury in these were gunshot, fall from standing height, fall from height, MVA, MBA, PVA and sports. Prevalance was 9.17% (47) of the total injuries in the knee. Prevalance in patients who were sent for CTA was 12.08%. Routine CTA in patients with injuries in the knee is not recomended. The use of ankle brachial index may decrease the number of CTA done

The October 2023 Trauma Roundup. 360. looks at: Intramedullary nailing versus sliding hip screw in trochanteric fracture management: the INSITE randomized clinical trial; Five-year outcomes for patients with a displaced fracture of the distal tibia; Direct anterior versus anterolateral approach in hip joint hemiarthroplasty; Proximal humerus fractures: treat them all nonoperatively?; Tranexamic acid administration by prehospital personnel; Locked plating versus nailing for proximal tibia fractures: a multicentre randomized controlled trial; A retrospective review of the rate of septic knee arthritis after retrograde femoral nailing for traumatic femoral fractures at a single academic institution

Introduction. Open fractures of the tibia are disabling injuries with a significant risk of deep infection. Treatment involves early antibiotic administration, early and aggressive surgical debridement, and may require complex soft tissue coverage techniques. The extent of disruption to the skin and soft-tissue envelope often varies, with ‘simple’ open fractures (defined by the Orthopaedic Trauma Society (OTS) open fracture severity classification) able to be closed primarily, whilst others may require shortening or soft-tissue reconstruction. This study aimed to determine whether OTS simple tibial open fractures received different rates of adequate debridement and plastic surgical presence at initial debridement, compared with OTS complex injuries, and whether rates of fracture-related infection, nonunion, or reoperation differed between the groups. Materials & Methods. A consecutive series of open tibia fractures managed at a tertiary UK Major Trauma Centre between January 2021 and November 2022 were included. Patient demographics, injury characteristics, timing of antibiotic delivery, timing and method of definitive fixation, and frequency of plastic surgical presence at initial debridement were retrospectively collected. The delivery of bone ends at initial debridement was used as a proxy for adequacy of surgical debridement. The primary outcome measure was rate of fracture-related infection, secondary outcomes included rates of reoperation, nonunion, and amputation. Chi2 Tests and independent samples T-tests were used to assess nominal and continuous outcomes respectively between simple and complex injuries. Ordinal data was assessed using nonparametric equivalent tests. Results. 79 patients with open fractures of the tibia were included. 70.8% of patients were male, with mean age 50.4 years (SD 19.2) and BMI 26.4 Kg/m2 (SD 6.0). Injuries were mostly sustained by low-energy falls (n = 28, 35.4%) and from road traffic accidents (n = 26, 32.9%). 27 (34.2%) were OTS simple open fractures. Simple open fractures were most commonly Gustillo-Anderson grade 1 (38.5%), or 2 (30.8%), whilst complex open fractures were mostly grade 3B (66.7%) (p < 0.001). Fracture-related infection rates in OTS simple and complex open fractures were 25.9% and 25.5% respectively (p = 0.967), and nonunion rates were 32% and 37.8% (p = 0.637). Primary amputation was less common in simple (0%) than in complex open fractures (20%, p = 0.012), there were no differences in delayed amputation rates (7.4% and 6% respectively, p = 0.811). Simple open fractures were less likely to have plastic surgeons present at initial debridement compared to complex open fractures (18.5% and 44%, p = 0.025), and less likely to have bone ends delivered through the skin at initial debridement (25.9% and 61.2%, p = 0.003). There were no differences in patient age, delays to antibiotic administration, or reoperation rates between OTS simple and OTS complex fractures (p > 0.05). Conclusions. Despite involving less significant soft tissue injury, OTS simple open tibia fractures had comparable deep infection and nonunion rates to complex fractures and received early plastic surgical input and adequate debridement less frequently. The severity of open fractures with less significant soft tissue injury may be underrecognized and therefore undertreated, although further prospective study is needed

This study aimed to investigate the outcomes of open tibia shaft fractures at a level one trauma center in a developing world setting. Specific objectives were to determine the association of time delay to antibiotic administration, surgical debridement, definitive skeletal stabilisation and soft tissue reconstruction, and the development of fracture-related infection (FRI). A retrospective cohort study included all adult patients with open tibia shaft fractures from July 2014 to June 2016 and January 2018 to December 2019. Patients who were skeletally immature at the time of injury, those with pathological fractures and who did not complete follow-up of at least three months were excluded. Patients were identified from hospital records. Data was captured in Microsoft Excel and analysed using STATISTICA. A Chi-squared was used to detect significant differences between groups. No association between infection and antibiotic administration was observed when patients were treated within or after 3 hours (p=0.625) or if patients had their first surgical debridement in theatre before or after 24 hours (p=0.259). Patients who waited more than five days for definitive skeletal fixation or soft tissue reconstruction had a significant increase in FRI (OR 4.7, 95% CI 2.0 – 10.9 and OR 4.7, 95% CI 2.0 – 11.0, respectively). Patients who underwent more than two formal debridements had a higher risk of developing FRI (OR 15.6, 95% CI 5.8 – 41.6). Whilst administration of antibiotics within 3 hours of presentation to the emergency unit had no impact on the development of FRI, time delays in managing open tibia shaft fractures are associated with an increased risk for FRI. Definitive soft tissue reconstruction and skeletal stabilization should not be delayed for more than five days

Osteosynthesis of high-energy metaphyseal proximal tibia fractures is still challenging, especially in patients with severe soft tissue injuries and/or short stature. Although the use of external fixators is the traditional treatment of choice for open comminuted fractures, patients' acceptance is low due to the high profile and therefore the physical burden of the devices. Recently, clinical case reports have shown that supercutaneous locked plating used as definite external fixation could be an efficient alternative. Therefore, the aim of this study was to evaluate the effect of implant configuration on stability and interfragmentary motions of unstable proximal tibia fractures fixed by means of externalized locked plating. Based on a right tibia CT scan of a 48 years-old male donor, a finite element model of an unstable proximal tibia fracture was developed to compare the stability of one internal and two different externalized plate fixations. A 2-cm osteotomy gap, located 5 cm distally to the articular surface and replicating an AO/OTA 41-C2.2 fracture, was virtually fixed with a medial stainless steel LISS-DF plate. Three implant configurations (IC) with different plate elevations were modelled and virtually tested biomechanically: IC-1 with 2-mm elevation (internal locked plate fixation), IC-2 with 22-mm elevation (externalized locked plate fixation with thin soft tissue simulation) and IC-3 with 32-mm elevation (externalized locked plate fixation with thick soft tissue simulation). Axial loads of 25 kg (partial weightbearing) and 80 kg (full weightbearing) were applied to the proximal tibia end and distributed at a ratio of 80%/20% on the medial/lateral condyles. A hinge joint was simulated at the distal end of the tibia. Parameters of interest were construct stiffness, as well as interfragmentary motion and longitudinal strain at the most lateral aspect of the fracture. Construct stiffness was 655 N/mm (IC-1), 197 N/mm (IC-2) and 128 N/mm (IC-3). Interfragmentary motions under partial weightbearing were 0.31 mm (IC-1), 1.09 mm (IC-2) and 1.74 mm (IC-3), whereas under full weightbearing they were 0.97 mm (IC-1), 3.50 mm (IC-2) and 5.56 mm (IC-3). The corresponding longitudinal strains at the fracture site under partial weightbearing were 1.55% (IC-1), 5.45% (IC-2) and 8.70% (IC-3). From virtual biomechanics point of view, externalized locked plating of unstable proximal tibia fractures with simulated thin and thick soft tissue environment seems to ensure favorable conditions for callus formation with longitudinal strains at the fracture site not exceeding 10%, thus providing appropriate relative stability for secondary bone healing under partial weightbearing during the early postoperative phase

Sonographic callus may enable assessment of fracture healing. The aim of this study was to establish a reliable method for three-dimensional reconstruction of sonographic callus. Patients that underwent non-operative management of displaced midshaft clavicle fractures and intramedullary nailing of tibia fractures were prospectively recruited and followed to union. Ultrasound scanning was performed at periodical time points following injury. Infra-red tracking technology was used to map each image to a three-dimensional lattice. Criteria was fist established for two-dimensional bridging callus detection in a pilot study. Using echo intensity of the ultrasound image, semi-automated mapping was used to create an anatomic three-dimensional representation of fracture healing. Agreement on the presence of sonographic bridging callus was assessed using the kappa coefficient and intra-class-correlation (ICC) between observers. 112 clavicle fractures and 10 tibia fractures completed follow-up at six months. Sonographic bridging callus was detected in 62.5% (n=70/112) of the clavicles at six weeks post-injury. If present, union occurred in 98.6% of the fractures (n=69/70). If absent, nonunion developed in 40.5% of cases (n=17/42)(73.4%-sensitive and 100%-specific to predict union). Out of 10 tibia fractures, 7 had bridging callus of at least one cortex at 6 weeks and when present all united. Of the three patients lacking sonographic bridging callus, one went onto a nonunion (77.8%-sensitive and 100%-specific to predict union). The ICC for sonographic callus between four reviewers was 0.82 (95% CI 0.68–0.91). Three-dimensional ultrasound reconstruction of bridging callus has the potential to identify impaired fracture healing at an early stage in fracture management